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diff --git a/gcc/ada/sem_ch12.adb b/gcc/ada/sem_ch12.adb new file mode 100644 index 00000000000..3f47a62627c --- /dev/null +++ b/gcc/ada/sem_ch12.adb @@ -0,0 +1,8932 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ C H 1 2 -- +-- -- +-- B o d y -- +-- -- +-- $Revision: 1.776 $ +-- -- +-- Copyright (C) 1992-2001, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Einfo; use Einfo; +with Elists; use Elists; +with Errout; use Errout; +with Expander; use Expander; +with Fname; use Fname; +with Fname.UF; use Fname.UF; +with Freeze; use Freeze; +with Hostparm; +with Inline; use Inline; +with Lib; use Lib; +with Lib.Load; use Lib.Load; +with Lib.Xref; use Lib.Xref; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Restrict; use Restrict; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Cat; use Sem_Cat; +with Sem_Ch3; use Sem_Ch3; +with Sem_Ch6; use Sem_Ch6; +with Sem_Ch7; use Sem_Ch7; +with Sem_Ch8; use Sem_Ch8; +with Sem_Ch10; use Sem_Ch10; +with Sem_Ch13; use Sem_Ch13; +with Sem_Elab; use Sem_Elab; +with Sem_Elim; use Sem_Elim; +with Sem_Eval; use Sem_Eval; +with Sem_Res; use Sem_Res; +with Sem_Type; use Sem_Type; +with Sem_Util; use Sem_Util; +with Stand; use Stand; +with Sinfo; use Sinfo; +with Sinfo.CN; use Sinfo.CN; +with Sinput; use Sinput; +with Sinput.L; use Sinput.L; +with Snames; use Snames; +with Stringt; use Stringt; +with Uname; use Uname; +with Table; +with Tbuild; use Tbuild; +with Uintp; use Uintp; +with Urealp; use Urealp; + +with GNAT.HTable; + +package body Sem_Ch12 is + + use Atree.Unchecked_Access; + -- This package performs untyped traversals of the tree, therefore it + -- needs direct access to the fields of a node. + + ---------------------------------------------------------- + -- Implementation of Generic Analysis and Instantiation -- + ----------------------------------------------------------- + + -- GNAT implements generics by macro expansion. No attempt is made to + -- share generic instantiations (for now). Analysis of a generic definition + -- does not perform any expansion action, but the expander must be called + -- on the tree for each instantiation, because the expansion may of course + -- depend on the generic actuals. All of this is best achieved as follows: + -- + -- a) Semantic analysis of a generic unit is performed on a copy of the + -- tree for the generic unit. All tree modifications that follow analysis + -- do not affect the original tree. Links are kept between the original + -- tree and the copy, in order to recognize non-local references within + -- the generic, and propagate them to each instance (recall that name + -- resolution is done on the generic declaration: generics are not really + -- macros!). This is summarized in the following diagram: + -- + -- .-----------. .----------. + -- | semantic |<--------------| generic | + -- | copy | | unit | + -- | |==============>| | + -- |___________| global |__________| + -- references | | | + -- | | | + -- .-----|--|. + -- | .-----|---. + -- | | .----------. + -- | | | generic | + -- |__| | | + -- |__| instance | + -- |__________| + -- + -- b) Each instantiation copies the original tree, and inserts into it a + -- series of declarations that describe the mapping between generic formals + -- and actuals. For example, a generic In OUT parameter is an object + -- renaming of the corresponing actual, etc. Generic IN parameters are + -- constant declarations. + -- + -- c) In order to give the right visibility for these renamings, we use + -- a different scheme for package and subprogram instantiations. For + -- packages, the list of renamings is inserted into the package + -- specification, before the visible declarations of the package. The + -- renamings are analyzed before any of the text of the instance, and are + -- thus visible at the right place. Furthermore, outside of the instance, + -- the generic parameters are visible and denote their corresponding + -- actuals. + + -- For subprograms, we create a container package to hold the renamings + -- and the subprogram instance itself. Analysis of the package makes the + -- renaming declarations visible to the subprogram. After analyzing the + -- package, the defining entity for the subprogram is touched-up so that + -- it appears declared in the current scope, and not inside the container + -- package. + + -- If the instantiation is a compilation unit, the container package is + -- given the same name as the subprogram instance. This ensures that + -- the elaboration procedure called by the binder, using the compilation + -- unit name, calls in fact the elaboration procedure for the package. + + -- Not surprisingly, private types complicate this approach. By saving in + -- the original generic object the non-local references, we guarantee that + -- the proper entities are referenced at the point of instantiation. + -- However, for private types, this by itself does not insure that the + -- proper VIEW of the entity is used (the full type may be visible at the + -- point of generic definition, but not at instantiation, or vice-versa). + -- In order to reference the proper view, we special-case any reference + -- to private types in the generic object, by saving both views, one in + -- the generic and one in the semantic copy. At time of instantiation, we + -- check whether the two views are consistent, and exchange declarations if + -- necessary, in order to restore the correct visibility. Similarly, if + -- the instance view is private when the generic view was not, we perform + -- the exchange. After completing the instantiation, we restore the + -- current visibility. The flag Has_Private_View marks identifiers in the + -- the generic unit that require checking. + + -- Visibility within nested generic units requires special handling. + -- Consider the following scheme: + -- + -- type Global is ... -- outside of generic unit. + -- generic ... + -- package Outer is + -- ... + -- type Semi_Global is ... -- global to inner. + -- + -- generic ... -- 1 + -- procedure inner (X1 : Global; X2 : Semi_Global); + -- + -- procedure in2 is new inner (...); -- 4 + -- end Outer; + + -- package New_Outer is new Outer (...); -- 2 + -- procedure New_Inner is new New_Outer.Inner (...); -- 3 + + -- The semantic analysis of Outer captures all occurrences of Global. + -- The semantic analysis of Inner (at 1) captures both occurrences of + -- Global and Semi_Global. + + -- At point 2 (instantiation of Outer), we also produce a generic copy + -- of Inner, even though Inner is, at that point, not being instantiated. + -- (This is just part of the semantic analysis of New_Outer). + + -- Critically, references to Global within Inner must be preserved, while + -- references to Semi_Global should not preserved, because they must now + -- resolve to an entity within New_Outer. To distinguish between these, we + -- use a global variable, Current_Instantiated_Parent, which is set when + -- performing a generic copy during instantiation (at 2). This variable is + -- used when performing a generic copy that is not an instantiation, but + -- that is nested within one, as the occurrence of 1 within 2. The analysis + -- of a nested generic only preserves references that are global to the + -- enclosing Current_Instantiated_Parent. We use the Scope_Depth value to + -- determine whether a reference is external to the given parent. + + -- The instantiation at point 3 requires no special treatment. The method + -- works as well for further nestings of generic units, but of course the + -- variable Current_Instantiated_Parent must be stacked because nested + -- instantiations can occur, e.g. the occurrence of 4 within 2. + + -- The instantiation of package and subprogram bodies is handled in a + -- similar manner, except that it is delayed until after semantic + -- analysis is complete. In this fashion complex cross-dependencies + -- between several package declarations and bodies containing generics + -- can be compiled which otherwise would diagnose spurious circularities. + + -- For example, it is possible to compile two packages A and B that + -- have the following structure: + + -- package A is package B is + -- generic ... generic ... + -- package G_A is package G_B is + + -- with B; with A; + -- package body A is package body B is + -- package N_B is new G_B (..) package N_A is new G_A (..) + + -- The table Pending_Instantiations in package Inline is used to keep + -- track of body instantiations that are delayed in this manner. Inline + -- handles the actual calls to do the body instantiations. This activity + -- is part of Inline, since the processing occurs at the same point, and + -- for essentially the same reason, as the handling of inlined routines. + + ---------------------------------------------- + -- Detection of Instantiation Circularities -- + ---------------------------------------------- + + -- If we have a chain of instantiations that is circular, this is a + -- static error which must be detected at compile time. The detection + -- of these circularities is carried out at the point that we insert + -- a generic instance spec or body. If there is a circularity, then + -- the analysis of the offending spec or body will eventually result + -- in trying to load the same unit again, and we detect this problem + -- as we analyze the package instantiation for the second time. + + -- At least in some cases after we have detected the circularity, we + -- get into trouble if we try to keep going. The following flag is + -- set if a circularity is detected, and used to abandon compilation + -- after the messages have been posted. + + Circularity_Detected : Boolean := False; + -- This should really be reset on encountering a new main unit, but in + -- practice we are not using multiple main units so it is not critical. + + ----------------------- + -- Local subprograms -- + ----------------------- + + procedure Abandon_Instantiation (N : Node_Id); + pragma No_Return (Abandon_Instantiation); + -- Posts an error message "instantiation abandoned" at the indicated + -- node and then raises the exception Instantiation_Error to do it. + + procedure Analyze_Formal_Array_Type + (T : in out Entity_Id; + Def : Node_Id); + -- A formal array type is treated like an array type declaration, and + -- invokes Array_Type_Declaration (sem_ch3) whose first parameter is + -- in-out, because in the case of an anonymous type the entity is + -- actually created in the procedure. + + -- The following procedures treat other kinds of formal parameters. + + procedure Analyze_Formal_Derived_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id); + + -- All the following need comments??? + + procedure Analyze_Formal_Decimal_Fixed_Point_Type + (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Discrete_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Floating_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Signed_Integer_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Modular_Type (T : Entity_Id; Def : Node_Id); + procedure Analyze_Formal_Ordinary_Fixed_Point_Type + (T : Entity_Id; Def : Node_Id); + + procedure Analyze_Formal_Private_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id); + -- This needs comments??? + + procedure Analyze_Generic_Formal_Part (N : Node_Id); + + procedure Analyze_Generic_Access_Type (T : Entity_Id; Def : Node_Id); + -- This needs comments ??? + + function Analyze_Associations + (I_Node : Node_Id; + Formals : List_Id; + F_Copy : List_Id) + return List_Id; + -- At instantiation time, build the list of associations between formals + -- and actuals. Each association becomes a renaming declaration for the + -- formal entity. F_Copy is the analyzed list of formals in the generic + -- copy. It is used to apply legality checks to the actuals. I_Node is the + -- instantiation node itself. + + procedure Analyze_Subprogram_Instantiation + (N : Node_Id; + K : Entity_Kind); + + procedure Build_Instance_Compilation_Unit_Nodes + (N : Node_Id; + Act_Body : Node_Id; + Act_Decl : Node_Id); + -- This procedure is used in the case where the generic instance of a + -- subprogram body or package body is a library unit. In this case, the + -- original library unit node for the generic instantiation must be + -- replaced by the resulting generic body, and a link made to a new + -- compilation unit node for the generic declaration. The argument N is + -- the original generic instantiation. Act_Body and Act_Decl are the body + -- and declaration of the instance (either package body and declaration + -- nodes or subprogram body and declaration nodes depending on the case). + -- On return, the node N has been rewritten with the actual body. + + procedure Check_Formal_Packages (P_Id : Entity_Id); + -- Apply the following to all formal packages in generic associations. + + procedure Check_Formal_Package_Instance + (Formal_Pack : Entity_Id; + Actual_Pack : Entity_Id); + -- Verify that the actuals of the actual instance match the actuals of + -- the template for a formal package that is not declared with a box. + + procedure Check_Forward_Instantiation (N : Node_Id; Decl : Node_Id); + -- If the generic is a local entity and the corresponding body has not + -- been seen yet, flag enclosing packages to indicate that it will be + -- elaborated after the generic body. Subprograms declared in the same + -- package cannot be inlined by the front-end because front-end inlining + -- requires a strict linear order of elaboration. + + procedure Check_Hidden_Child_Unit + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl_Id : Entity_Id); + -- If the generic unit is an implicit child instance within a parent + -- instance, we need to make an explicit test that it is not hidden by + -- a child instance of the same name and parent. + + procedure Check_Private_View (N : Node_Id); + -- Check whether the type of a generic entity has a different view between + -- the point of generic analysis and the point of instantiation. If the + -- view has changed, then at the point of instantiation we restore the + -- correct view to perform semantic analysis of the instance, and reset + -- the current view after instantiation. The processing is driven by the + -- current private status of the type of the node, and Has_Private_View, + -- a flag that is set at the point of generic compilation. If view and + -- flag are inconsistent then the type is updated appropriately. + + procedure Check_Generic_Actuals + (Instance : Entity_Id; + Is_Formal_Box : Boolean); + -- Similar to previous one. Check the actuals in the instantiation, + -- whose views can change between the point of instantiation and the point + -- of instantiation of the body. In addition, mark the generic renamings + -- as generic actuals, so that they are not compatible with other actuals. + -- Recurse on an actual that is a formal package whose declaration has + -- a box. + + function Contains_Instance_Of + (Inner : Entity_Id; + Outer : Entity_Id; + N : Node_Id) + return Boolean; + -- Inner is instantiated within the generic Outer. Check whether Inner + -- directly or indirectly contains an instance of Outer or of one of its + -- parents, in the case of a subunit. Each generic unit holds a list of + -- the entities instantiated within (at any depth). This procedure + -- determines whether the set of such lists contains a cycle, i.e. an + -- illegal circular instantiation. + + function Denotes_Formal_Package (Pack : Entity_Id) return Boolean; + -- Returns True if E is a formal package of an enclosing generic, or + -- the actual for such a formal in an enclosing instantiation. Used in + -- Restore_Private_Views, to keep the formals of such a package visible + -- on exit from an inner instantiation. + + function Find_Actual_Type + (Typ : Entity_Id; + Gen_Scope : Entity_Id) + return Entity_Id; + -- When validating the actual types of a child instance, check whether + -- the formal is a formal type of the parent unit, and retrieve the current + -- actual for it. Typ is the entity in the analyzed formal type declaration + -- (component or index type of an array type) and Gen_Scope is the scope of + -- the analyzed formal array type. + + function Get_Package_Instantiation_Node (A : Entity_Id) return Node_Id; + -- Given the entity of a unit that is an instantiation, retrieve the + -- original instance node. This is used when loading the instantiations + -- of the ancestors of a child generic that is being instantiated. + + function In_Same_Declarative_Part + (F_Node : Node_Id; + Inst : Node_Id) + return Boolean; + -- True if the instantiation Inst and the given freeze_node F_Node appear + -- within the same declarative part, ignoring subunits, but with no inter- + -- vening suprograms or concurrent units. If true, the freeze node + -- of the instance can be placed after the freeze node of the parent, + -- which it itself an instance. + + procedure Set_Instance_Of (A : Entity_Id; B : Entity_Id); + -- Associate analyzed generic parameter with corresponding + -- instance. Used for semantic checks at instantiation time. + + function Has_Been_Exchanged (E : Entity_Id) return Boolean; + -- Traverse the Exchanged_Views list to see if a type was private + -- and has already been flipped during this phase of instantiation. + + procedure Hide_Current_Scope; + -- When compiling a generic child unit, the parent context must be + -- present, but the instance and all entities that may be generated + -- must be inserted in the current scope. We leave the current scope + -- on the stack, but make its entities invisible to avoid visibility + -- problems. This is reversed at the end of instantiations. This is + -- not done for the instantiation of the bodies, which only require the + -- instances of the generic parents to be in scope. + + procedure Install_Body + (Act_Body : Node_Id; + N : Node_Id; + Gen_Body : Node_Id; + Gen_Decl : Node_Id); + -- If the instantiation happens textually before the body of the generic, + -- the instantiation of the body must be analyzed after the generic body, + -- and not at the point of instantiation. Such early instantiations can + -- happen if the generic and the instance appear in a package declaration + -- because the generic body can only appear in the corresponding package + -- body. Early instantiations can also appear if generic, instance and + -- body are all in the declarative part of a subprogram or entry. Entities + -- of packages that are early instantiations are delayed, and their freeze + -- node appears after the generic body. + + procedure Insert_After_Last_Decl (N : Node_Id; F_Node : Node_Id); + -- Insert freeze node at the end of the declarative part that includes the + -- instance node N. If N is in the visible part of an enclosing package + -- declaration, the freeze node has to be inserted at the end of the + -- private declarations, if any. + + procedure Freeze_Subprogram_Body + (Inst_Node : Node_Id; + Gen_Body : Node_Id; + Pack_Id : Entity_Id); + -- The generic body may appear textually after the instance, including + -- in the proper body of a stub, or within a different package instance. + -- Given that the instance can only be elaborated after the generic, we + -- place freeze_nodes for the instance and/or for packages that may enclose + -- the instance and the generic, so that the back-end can establish the + -- proper order of elaboration. + + procedure Install_Parent (P : Entity_Id; In_Body : Boolean := False); + -- When compiling an instance of a child unit the parent (which is + -- itself an instance) is an enclosing scope that must be made + -- immediately visible. This procedure is also used to install the non- + -- generic parent of a generic child unit when compiling its body, so that + -- full views of types in the parent are made visible. + + procedure Remove_Parent (In_Body : Boolean := False); + -- Reverse effect after instantiation of child is complete. + + procedure Inline_Instance_Body + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl : Node_Id); + -- If front-end inlining is requested, instantiate the package body, + -- and preserve the visibility of its compilation unit, to insure + -- that successive instantiations succeed. + + -- The functions Instantiate_XXX perform various legality checks and build + -- the declarations for instantiated generic parameters. + -- Need to describe what the parameters are ??? + + function Instantiate_Object + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return List_Id; + + function Instantiate_Type + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return Node_Id; + + function Instantiate_Formal_Subprogram + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return Node_Id; + + function Instantiate_Formal_Package + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return List_Id; + -- If the formal package is declared with a box, special visibility rules + -- apply to its formals: they are in the visible part of the package. This + -- is true in the declarative region of the formal package, that is to say + -- in the enclosing generic or instantiation. For an instantiation, the + -- parameters of the formal package are made visible in an explicit step. + -- Furthermore, if the actual is a visible use_clause, these formals must + -- be made potentially use_visible as well. On exit from the enclosing + -- instantiation, the reverse must be done. + + -- For a formal package declared without a box, there are conformance rules + -- that apply to the actuals in the generic declaration and the actuals of + -- the actual package in the enclosing instantiation. The simplest way to + -- apply these rules is to repeat the instantiation of the formal package + -- in the context of the enclosing instance, and compare the generic + -- associations of this instantiation with those of the actual package. + + function Is_In_Main_Unit (N : Node_Id) return Boolean; + -- Test if given node is in the main unit + + procedure Load_Parent_Of_Generic (N : Node_Id; Spec : Node_Id); + -- If the generic appears in a separate non-generic library unit, + -- load the corresponding body to retrieve the body of the generic. + -- N is the node for the generic instantiation, Spec is the generic + -- package declaration. + + procedure Inherit_Context (Gen_Decl : Node_Id; Inst : Node_Id); + -- Add the context clause of the unit containing a generic unit to + -- an instantiation that is a compilation unit. + + function Associated_Node (N : Node_Id) return Node_Id; + -- In order to propagate semantic information back from the analyzed + -- copy to the original generic, we maintain links between selected nodes + -- in the generic and their corresponding copies. At the end of generic + -- analysis, the routine Save_Global_References traverses the generic + -- tree, examines the semantic information, and preserves the links to + -- those nodes that contain global information. At instantiation, the + -- information from the associated node is placed on the new copy, so that + -- name resolution is not repeated. + -- Two kinds of nodes have associated nodes: + + -- a) those that contain entities, that is to say identifiers, expanded_ + -- names, and operators. + + -- b) aggregates. + + -- For the first class, the associated node preserves the entity if it is + -- global. If the generic contains nested instantiations, the associated_ + -- node itself has been recopied, and a chain of them must be followed. + + -- For aggregates, the associated node allows retrieval of the type, which + -- may otherwise not appear in the generic. The view of this type may be + -- different between generic and instantiation, and the full view can be + -- installed before the instantiation is analyzed. For aggregates of + -- type extensions, the same view exchange may have to be performed for + -- some of the ancestor types, if their view is private at the point of + -- instantiation. + + -- The associated node is stored in Node4, using this field as a free + -- union in a fashion that should clearly be under control of sinfo ??? + + procedure Move_Freeze_Nodes + (Out_Of : Entity_Id; + After : Node_Id; + L : List_Id); + -- Freeze nodes can be generated in the analysis of a generic unit, but + -- will not be seen by the back-end. It is necessary to move those nodes + -- to the enclosing scope if they freeze an outer entity. We place them + -- at the end of the enclosing generic package, which is semantically + -- neutral. + + procedure Pre_Analyze_Actuals (N : Node_Id); + -- Analyze actuals to perform name resolution. Full resolution is done + -- later, when the expected types are known, but names have to be captured + -- before installing parents of generics, that are not visible for the + -- actuals themselves. + + procedure Set_Associated_Node + (Gen_Node : Node_Id; + Copy_Node : Node_Id); + -- Establish the link between an identifier in the generic unit, and the + -- corresponding node in the semantic copy. + + procedure Valid_Default_Attribute (Nam : Entity_Id; Def : Node_Id); + -- Verify that an attribute that appears as the default for a formal + -- subprogram is a function or procedure with the correct profile. + + ------------------------------------------- + -- Data Structures for Generic Renamings -- + ------------------------------------------- + + -- The map Generic_Renamings associates generic entities with their + -- corresponding actuals. Currently used to validate type instances. + -- It will eventually be used for all generic parameters to eliminate + -- the need for overload resolution in the instance. + + type Assoc_Ptr is new Int; + + Assoc_Null : constant Assoc_Ptr := -1; + + type Assoc is record + Gen_Id : Entity_Id; + Act_Id : Entity_Id; + Next_In_HTable : Assoc_Ptr; + end record; + + package Generic_Renamings is new Table.Table + (Table_Component_Type => Assoc, + Table_Index_Type => Assoc_Ptr, + Table_Low_Bound => 0, + Table_Initial => 10, + Table_Increment => 100, + Table_Name => "Generic_Renamings"); + + -- Variable to hold enclosing instantiation. When the environment is + -- saved for a subprogram inlining, the corresponding Act_Id is empty. + + Current_Instantiated_Parent : Assoc := (Empty, Empty, Assoc_Null); + + -- Hash table for associations + + HTable_Size : constant := 37; + type HTable_Range is range 0 .. HTable_Size - 1; + + procedure Set_Next_Assoc (E : Assoc_Ptr; Next : Assoc_Ptr); + function Next_Assoc (E : Assoc_Ptr) return Assoc_Ptr; + function Get_Gen_Id (E : Assoc_Ptr) return Entity_Id; + function Hash (F : Entity_Id) return HTable_Range; + + package Generic_Renamings_HTable is new GNAT.HTable.Static_HTable ( + Header_Num => HTable_Range, + Element => Assoc, + Elmt_Ptr => Assoc_Ptr, + Null_Ptr => Assoc_Null, + Set_Next => Set_Next_Assoc, + Next => Next_Assoc, + Key => Entity_Id, + Get_Key => Get_Gen_Id, + Hash => Hash, + Equal => "="); + + Exchanged_Views : Elist_Id; + -- This list holds the private views that have been exchanged during + -- instantiation to restore the visibility of the generic declaration. + -- (see comments above). After instantiation, the current visibility is + -- reestablished by means of a traversal of this list. + + Hidden_Entities : Elist_Id; + -- This list holds the entities of the current scope that are removed + -- from immediate visibility when instantiating a child unit. Their + -- visibility is restored in Remove_Parent. + + -- Because instantiations can be recursive, the following must be saved + -- on entry and restored on exit from an instantiation (spec or body). + -- This is done by the two procedures Save_Env and Restore_Env. + + type Instance_Env is record + Ada_83 : Boolean; + Instantiated_Parent : Assoc; + Exchanged_Views : Elist_Id; + Hidden_Entities : Elist_Id; + Current_Sem_Unit : Unit_Number_Type; + end record; + + package Instance_Envs is new Table.Table ( + Table_Component_Type => Instance_Env, + Table_Index_Type => Int, + Table_Low_Bound => 0, + Table_Initial => 32, + Table_Increment => 100, + Table_Name => "Instance_Envs"); + + procedure Restore_Private_Views + (Pack_Id : Entity_Id; + Is_Package : Boolean := True); + -- Restore the private views of external types, and unmark the generic + -- renamings of actuals, so that they become comptible subtypes again. + -- For subprograms, Pack_Id is the package constructed to hold the + -- renamings. + + procedure Switch_View (T : Entity_Id); + -- Switch the partial and full views of a type and its private + -- dependents (i.e. its subtypes and derived types). + + ------------------------------------ + -- Structures for Error Reporting -- + ------------------------------------ + + Instantiation_Node : Node_Id; + -- Used by subprograms that validate instantiation of formal parameters + -- where there might be no actual on which to place the error message. + -- Also used to locate the instantiation node for generic subunits. + + Instantiation_Error : exception; + -- When there is a semantic error in the generic parameter matching, + -- there is no point in continuing the instantiation, because the + -- number of cascaded errors is unpredictable. This exception aborts + -- the instantiation process altogether. + + S_Adjustment : Sloc_Adjustment; + -- Offset created for each node in an instantiation, in order to keep + -- track of the source position of the instantiation in each of its nodes. + -- A subsequent semantic error or warning on a construct of the instance + -- points to both places: the original generic node, and the point of + -- instantiation. See Sinput and Sinput.L for additional details. + + ------------------------------------------------------------ + -- Data structure for keeping track when inside a Generic -- + ------------------------------------------------------------ + + -- The following table is used to save values of the Inside_A_Generic + -- flag (see spec of Sem) when they are saved by Start_Generic. + + package Generic_Flags is new Table.Table ( + Table_Component_Type => Boolean, + Table_Index_Type => Int, + Table_Low_Bound => 0, + Table_Initial => 32, + Table_Increment => 200, + Table_Name => "Generic_Flags"); + + --------------------------- + -- Abandon_Instantiation -- + --------------------------- + + procedure Abandon_Instantiation (N : Node_Id) is + begin + Error_Msg_N ("instantiation abandoned!", N); + raise Instantiation_Error; + end Abandon_Instantiation; + + -------------------------- + -- Analyze_Associations -- + -------------------------- + + function Analyze_Associations + (I_Node : Node_Id; + Formals : List_Id; + F_Copy : List_Id) + return List_Id + is + Actuals : List_Id := Generic_Associations (I_Node); + Actual : Node_Id; + Actual_Types : Elist_Id := New_Elmt_List; + Assoc : List_Id := New_List; + Formal : Node_Id; + Next_Formal : Node_Id; + Temp_Formal : Node_Id; + Analyzed_Formal : Node_Id; + Defaults : Elist_Id := New_Elmt_List; + Match : Node_Id; + Named : Node_Id; + First_Named : Node_Id := Empty; + Found_Assoc : Node_Id; + Is_Named_Assoc : Boolean; + Num_Matched : Int := 0; + Num_Actuals : Int := 0; + + function Matching_Actual + (F : Entity_Id; + A_F : Entity_Id) + return Node_Id; + -- Find actual that corresponds to a given a formal parameter. If the + -- actuals are positional, return the next one, if any. If the actuals + -- are named, scan the parameter associations to find the right one. + -- A_F is the corresponding entity in the analyzed generic,which is + -- placed on the selector name for ASIS use. + + procedure Set_Analyzed_Formal; + -- Find the node in the generic copy that corresponds to a given formal. + -- The semantic information on this node is used to perform legality + -- checks on the actuals. Because semantic analysis can introduce some + -- anonymous entities or modify the declaration node itself, the + -- correspondence between the two lists is not one-one. In addition to + -- anonymous types, the presence a formal equality will introduce an + -- implicit declaration for the corresponding inequality. + + --------------------- + -- Matching_Actual -- + --------------------- + + function Matching_Actual + (F : Entity_Id; + A_F : Entity_Id) + return Node_Id + is + Found : Node_Id; + Prev : Node_Id; + + begin + Is_Named_Assoc := False; + + -- End of list of purely positional parameters + + if No (Actual) then + Found := Empty; + + -- Case of positional parameter corresponding to current formal + + elsif No (Selector_Name (Actual)) then + Found := Explicit_Generic_Actual_Parameter (Actual); + Found_Assoc := Actual; + Num_Matched := Num_Matched + 1; + Next (Actual); + + -- Otherwise scan list of named actuals to find the one with the + -- desired name. All remaining actuals have explicit names. + + else + Is_Named_Assoc := True; + Found := Empty; + Prev := Empty; + + while Present (Actual) loop + if Chars (Selector_Name (Actual)) = Chars (F) then + Found := Explicit_Generic_Actual_Parameter (Actual); + Set_Entity (Selector_Name (Actual), A_F); + Set_Etype (Selector_Name (Actual), Etype (A_F)); + Found_Assoc := Actual; + Num_Matched := Num_Matched + 1; + exit; + end if; + + Prev := Actual; + Next (Actual); + end loop; + + -- Reset for subsequent searches. In most cases the named + -- associations are in order. If they are not, we reorder them + -- to avoid scanning twice the same actual. This is not just a + -- question of efficiency: there may be multiple defaults with + -- boxes that have the same name. In a nested instantiation we + -- insert actuals for those defaults, and cannot rely on their + -- names to disambiguate them. + + if Actual = First_Named then + Next (First_Named); + + elsif Present (Actual) then + Insert_Before (First_Named, Remove_Next (Prev)); + end if; + + Actual := First_Named; + end if; + + return Found; + end Matching_Actual; + + ------------------------- + -- Set_Analyzed_Formal -- + ------------------------- + + procedure Set_Analyzed_Formal is + Kind : Node_Kind; + begin + while Present (Analyzed_Formal) loop + Kind := Nkind (Analyzed_Formal); + + case Nkind (Formal) is + + when N_Formal_Subprogram_Declaration => + exit when Kind = N_Formal_Subprogram_Declaration + and then + Chars + (Defining_Unit_Name (Specification (Formal))) = + Chars + (Defining_Unit_Name (Specification (Analyzed_Formal))); + + when N_Formal_Package_Declaration => + exit when + Kind = N_Formal_Package_Declaration + or else + Kind = N_Generic_Package_Declaration; + + when N_Use_Package_Clause | N_Use_Type_Clause => exit; + + when others => + + -- Skip freeze nodes, and nodes inserted to replace + -- unrecognized pragmas. + + exit when + Kind /= N_Formal_Subprogram_Declaration + and then Kind /= N_Subprogram_Declaration + and then Kind /= N_Freeze_Entity + and then Kind /= N_Null_Statement + and then Kind /= N_Itype_Reference + and then Chars (Defining_Identifier (Formal)) = + Chars (Defining_Identifier (Analyzed_Formal)); + end case; + + Next (Analyzed_Formal); + end loop; + + end Set_Analyzed_Formal; + + -- Start of processing for Analyze_Associations + + begin + -- If named associations are present, save the first named association + -- (it may of course be Empty) to facilitate subsequent name search. + + if Present (Actuals) then + First_Named := First (Actuals); + + while Present (First_Named) + and then No (Selector_Name (First_Named)) + loop + Num_Actuals := Num_Actuals + 1; + Next (First_Named); + end loop; + end if; + + Named := First_Named; + while Present (Named) loop + if No (Selector_Name (Named)) then + Error_Msg_N ("invalid positional actual after named one", Named); + Abandon_Instantiation (Named); + end if; + + Num_Actuals := Num_Actuals + 1; + Next (Named); + end loop; + + if Present (Formals) then + Formal := First_Non_Pragma (Formals); + Analyzed_Formal := First_Non_Pragma (F_Copy); + + if Present (Actuals) then + Actual := First (Actuals); + + -- All formals should have default values + + else + Actual := Empty; + end if; + + while Present (Formal) loop + Set_Analyzed_Formal; + Next_Formal := Next_Non_Pragma (Formal); + + case Nkind (Formal) is + when N_Formal_Object_Declaration => + Match := + Matching_Actual ( + Defining_Identifier (Formal), + Defining_Identifier (Analyzed_Formal)); + + Append_List + (Instantiate_Object (Formal, Match, Analyzed_Formal), + Assoc); + + when N_Formal_Type_Declaration => + Match := + Matching_Actual ( + Defining_Identifier (Formal), + Defining_Identifier (Analyzed_Formal)); + + if No (Match) then + Error_Msg_NE ("missing actual for instantiation of &", + Instantiation_Node, Defining_Identifier (Formal)); + Abandon_Instantiation (Instantiation_Node); + + else + Analyze (Match); + Append_To (Assoc, + Instantiate_Type (Formal, Match, Analyzed_Formal)); + + -- an instantiation is a freeze point for the actuals, + -- unless this is a rewritten formal package. + + if Nkind (I_Node) /= N_Formal_Package_Declaration then + Append_Elmt (Entity (Match), Actual_Types); + end if; + end if; + + -- A remote access-to-class-wide type must not be an + -- actual parameter for a generic formal of an access + -- type (E.2.2 (17)). + + if Nkind (Analyzed_Formal) = N_Formal_Type_Declaration + and then + Nkind (Formal_Type_Definition (Analyzed_Formal)) = + N_Access_To_Object_Definition + then + Validate_Remote_Access_To_Class_Wide_Type (Match); + end if; + + when N_Formal_Subprogram_Declaration => + Match := + Matching_Actual ( + Defining_Unit_Name (Specification (Formal)), + Defining_Unit_Name (Specification (Analyzed_Formal))); + + -- If the formal subprogram has the same name as + -- another formal subprogram of the generic, then + -- a named association is illegal (12.3(9)). Exclude + -- named associations that are generated for a nested + -- instance. + + if Present (Match) + and then Is_Named_Assoc + and then Comes_From_Source (Found_Assoc) + then + Temp_Formal := First (Formals); + while Present (Temp_Formal) loop + if Nkind (Temp_Formal) = + N_Formal_Subprogram_Declaration + and then Temp_Formal /= Formal + and then + Chars (Selector_Name (Found_Assoc)) = + Chars (Defining_Unit_Name + (Specification (Temp_Formal))) + then + Error_Msg_N + ("name not allowed for overloaded formal", + Found_Assoc); + Abandon_Instantiation (Instantiation_Node); + end if; + + Next (Temp_Formal); + end loop; + end if; + + Append_To (Assoc, + Instantiate_Formal_Subprogram + (Formal, Match, Analyzed_Formal)); + + if No (Match) + and then Box_Present (Formal) + then + Append_Elmt + (Defining_Unit_Name (Specification (Last (Assoc))), + Defaults); + end if; + + when N_Formal_Package_Declaration => + Match := + Matching_Actual ( + Defining_Identifier (Formal), + Defining_Identifier (Original_Node (Analyzed_Formal))); + + if No (Match) then + Error_Msg_NE + ("missing actual for instantiation of&", + Instantiation_Node, + Defining_Identifier (Formal)); + + Abandon_Instantiation (Instantiation_Node); + + else + Analyze (Match); + Append_List + (Instantiate_Formal_Package + (Formal, Match, Analyzed_Formal), + Assoc); + end if; + + -- For use type and use package appearing in the context + -- clause, we have already copied them, so we can just + -- move them where they belong (we mustn't recopy them + -- since this would mess up the Sloc values). + + when N_Use_Package_Clause | + N_Use_Type_Clause => + Remove (Formal); + Append (Formal, Assoc); + + when others => + raise Program_Error; + + end case; + + Formal := Next_Formal; + Next_Non_Pragma (Analyzed_Formal); + end loop; + + if Num_Actuals > Num_Matched then + Error_Msg_N + ("unmatched actuals in instantiation", Instantiation_Node); + end if; + + elsif Present (Actuals) then + Error_Msg_N + ("too many actuals in generic instantiation", Instantiation_Node); + end if; + + declare + Elmt : Elmt_Id := First_Elmt (Actual_Types); + + begin + while Present (Elmt) loop + Freeze_Before (I_Node, Node (Elmt)); + Next_Elmt (Elmt); + end loop; + end; + + -- If there are default subprograms, normalize the tree by adding + -- explicit associations for them. This is required if the instance + -- appears within a generic. + + declare + Elmt : Elmt_Id; + Subp : Entity_Id; + New_D : Node_Id; + + begin + Elmt := First_Elmt (Defaults); + while Present (Elmt) loop + if No (Actuals) then + Actuals := New_List; + Set_Generic_Associations (I_Node, Actuals); + end if; + + Subp := Node (Elmt); + New_D := + Make_Generic_Association (Sloc (Subp), + Selector_Name => New_Occurrence_Of (Subp, Sloc (Subp)), + Explicit_Generic_Actual_Parameter => + New_Occurrence_Of (Subp, Sloc (Subp))); + Mark_Rewrite_Insertion (New_D); + Append_To (Actuals, New_D); + Next_Elmt (Elmt); + end loop; + end; + + return Assoc; + end Analyze_Associations; + + ------------------------------- + -- Analyze_Formal_Array_Type -- + ------------------------------- + + procedure Analyze_Formal_Array_Type + (T : in out Entity_Id; + Def : Node_Id) + is + DSS : Node_Id; + + begin + -- Treated like a non-generic array declaration, with + -- additional semantic checks. + + Enter_Name (T); + + if Nkind (Def) = N_Constrained_Array_Definition then + DSS := First (Discrete_Subtype_Definitions (Def)); + while Present (DSS) loop + if Nkind (DSS) = N_Subtype_Indication + or else Nkind (DSS) = N_Range + or else Nkind (DSS) = N_Attribute_Reference + then + Error_Msg_N ("only a subtype mark is allowed in a formal", DSS); + end if; + + Next (DSS); + end loop; + end if; + + Array_Type_Declaration (T, Def); + Set_Is_Generic_Type (Base_Type (T)); + + if Ekind (Component_Type (T)) = E_Incomplete_Type + and then No (Full_View (Component_Type (T))) + then + Error_Msg_N ("premature usage of incomplete type", Def); + + elsif Is_Internal (Component_Type (T)) + and then Nkind (Original_Node (Subtype_Indication (Def))) + /= N_Attribute_Reference + then + Error_Msg_N + ("only a subtype mark is allowed in a formal", + Subtype_Indication (Def)); + end if; + + end Analyze_Formal_Array_Type; + + --------------------------------------------- + -- Analyze_Formal_Decimal_Fixed_Point_Type -- + --------------------------------------------- + + -- As for other generic types, we create a valid type representation + -- with legal but arbitrary attributes, whose values are never considered + -- static. For all scalar types we introduce an anonymous base type, with + -- the same attributes. We choose the corresponding integer type to be + -- Standard_Integer. + + procedure Analyze_Formal_Decimal_Fixed_Point_Type + (T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + Base : constant Entity_Id := + New_Internal_Entity + (E_Decimal_Fixed_Point_Type, + Current_Scope, Sloc (Def), 'G'); + Int_Base : constant Entity_Id := Standard_Integer; + Delta_Val : constant Ureal := Ureal_1; + Digs_Val : constant Uint := Uint_6; + + begin + Enter_Name (T); + + Set_Etype (Base, Base); + Set_Size_Info (Base, Int_Base); + Set_RM_Size (Base, RM_Size (Int_Base)); + Set_First_Rep_Item (Base, First_Rep_Item (Int_Base)); + Set_Digits_Value (Base, Digs_Val); + Set_Delta_Value (Base, Delta_Val); + Set_Small_Value (Base, Delta_Val); + Set_Scalar_Range (Base, + Make_Range (Loc, + Low_Bound => Make_Real_Literal (Loc, Ureal_1), + High_Bound => Make_Real_Literal (Loc, Ureal_1))); + + Set_Is_Generic_Type (Base); + Set_Parent (Base, Parent (Def)); + + Set_Ekind (T, E_Decimal_Fixed_Point_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, Int_Base); + Set_RM_Size (T, RM_Size (Int_Base)); + Set_First_Rep_Item (T, First_Rep_Item (Int_Base)); + Set_Digits_Value (T, Digs_Val); + Set_Delta_Value (T, Delta_Val); + Set_Small_Value (T, Delta_Val); + Set_Scalar_Range (T, Scalar_Range (Base)); + + end Analyze_Formal_Decimal_Fixed_Point_Type; + + --------------------------------- + -- Analyze_Formal_Derived_Type -- + --------------------------------- + + procedure Analyze_Formal_Derived_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + New_N : Node_Id; + Unk_Disc : Boolean := Unknown_Discriminants_Present (N); + + begin + Set_Is_Generic_Type (T); + + if Private_Present (Def) then + New_N := + Make_Private_Extension_Declaration (Loc, + Defining_Identifier => T, + Discriminant_Specifications => Discriminant_Specifications (N), + Unknown_Discriminants_Present => Unk_Disc, + Subtype_Indication => Subtype_Mark (Def)); + + Set_Abstract_Present (New_N, Abstract_Present (Def)); + + else + New_N := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => T, + Discriminant_Specifications => + Discriminant_Specifications (Parent (T)), + Type_Definition => + Make_Derived_Type_Definition (Loc, + Subtype_Indication => Subtype_Mark (Def))); + + Set_Abstract_Present + (Type_Definition (New_N), Abstract_Present (Def)); + end if; + + Rewrite (N, New_N); + Analyze (N); + + if Unk_Disc then + if not Is_Composite_Type (T) then + Error_Msg_N + ("unknown discriminants not allowed for elementary types", N); + else + Set_Has_Unknown_Discriminants (T); + Set_Is_Constrained (T, False); + end if; + end if; + + -- If the parent type has a known size, so does the formal, which + -- makes legal representation clauses that involve the formal. + + Set_Size_Known_At_Compile_Time + (T, Size_Known_At_Compile_Time (Entity (Subtype_Mark (Def)))); + + end Analyze_Formal_Derived_Type; + + ---------------------------------- + -- Analyze_Formal_Discrete_Type -- + ---------------------------------- + + -- The operations defined for a discrete types are those of an + -- enumeration type. The size is set to an arbitrary value, for use + -- in analyzing the generic unit. + + procedure Analyze_Formal_Discrete_Type (T : Entity_Id; Def : Node_Id) is + Loc : constant Source_Ptr := Sloc (Def); + Lo : Node_Id; + Hi : Node_Id; + + begin + Enter_Name (T); + Set_Ekind (T, E_Enumeration_Type); + Set_Etype (T, T); + Init_Size (T, 8); + Init_Alignment (T); + + -- For semantic analysis, the bounds of the type must be set to some + -- non-static value. The simplest is to create attribute nodes for + -- those bounds, that refer to the type itself. These bounds are never + -- analyzed but serve as place-holders. + + Lo := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => New_Reference_To (T, Loc)); + Set_Etype (Lo, T); + + Hi := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => New_Reference_To (T, Loc)); + Set_Etype (Hi, T); + + Set_Scalar_Range (T, + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi)); + + end Analyze_Formal_Discrete_Type; + + ---------------------------------- + -- Analyze_Formal_Floating_Type -- + --------------------------------- + + procedure Analyze_Formal_Floating_Type (T : Entity_Id; Def : Node_Id) is + Base : constant Entity_Id := + New_Internal_Entity + (E_Floating_Point_Type, Current_Scope, Sloc (Def), 'G'); + + begin + -- The various semantic attributes are taken from the predefined type + -- Float, just so that all of them are initialized. Their values are + -- never used because no constant folding or expansion takes place in + -- the generic itself. + + Enter_Name (T); + Set_Ekind (T, E_Floating_Point_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, (Standard_Float)); + Set_RM_Size (T, RM_Size (Standard_Float)); + Set_Digits_Value (T, Digits_Value (Standard_Float)); + Set_Scalar_Range (T, Scalar_Range (Standard_Float)); + + Set_Is_Generic_Type (Base); + Set_Etype (Base, Base); + Set_Size_Info (Base, (Standard_Float)); + Set_RM_Size (Base, RM_Size (Standard_Float)); + Set_Digits_Value (Base, Digits_Value (Standard_Float)); + Set_Scalar_Range (Base, Scalar_Range (Standard_Float)); + Set_Parent (Base, Parent (Def)); + end Analyze_Formal_Floating_Type; + + --------------------------------- + -- Analyze_Formal_Modular_Type -- + --------------------------------- + + procedure Analyze_Formal_Modular_Type (T : Entity_Id; Def : Node_Id) is + begin + -- Apart from their entity kind, generic modular types are treated + -- like signed integer types, and have the same attributes. + + Analyze_Formal_Signed_Integer_Type (T, Def); + Set_Ekind (T, E_Modular_Integer_Subtype); + Set_Ekind (Etype (T), E_Modular_Integer_Type); + + end Analyze_Formal_Modular_Type; + + --------------------------------------- + -- Analyze_Formal_Object_Declaration -- + --------------------------------------- + + procedure Analyze_Formal_Object_Declaration (N : Node_Id) is + E : constant Node_Id := Expression (N); + Id : Node_Id := Defining_Identifier (N); + K : Entity_Kind; + T : Node_Id; + + begin + Enter_Name (Id); + + -- Determine the mode of the formal object + + if Out_Present (N) then + K := E_Generic_In_Out_Parameter; + + if not In_Present (N) then + Error_Msg_N ("formal generic objects cannot have mode OUT", N); + end if; + + else + K := E_Generic_In_Parameter; + end if; + + Find_Type (Subtype_Mark (N)); + T := Entity (Subtype_Mark (N)); + + if Ekind (T) = E_Incomplete_Type then + Error_Msg_N ("premature usage of incomplete type", Subtype_Mark (N)); + end if; + + if K = E_Generic_In_Parameter then + if Is_Limited_Type (T) then + Error_Msg_N + ("generic formal of mode IN must not be of limited type", N); + end if; + + if Is_Abstract (T) then + Error_Msg_N + ("generic formal of mode IN must not be of abstract type", N); + end if; + + if Present (E) then + Analyze_Default_Expression (E, T); + end if; + + Set_Ekind (Id, K); + Set_Etype (Id, T); + + -- Case of generic IN OUT parameter. + + else + -- If the formal has an unconstrained type, construct its + -- actual subtype, as is done for subprogram formals. In this + -- fashion, all its uses can refer to specific bounds. + + Set_Ekind (Id, K); + Set_Etype (Id, T); + + if (Is_Array_Type (T) + and then not Is_Constrained (T)) + or else + (Ekind (T) = E_Record_Type + and then Has_Discriminants (T)) + then + declare + Non_Freezing_Ref : constant Node_Id := + New_Reference_To (Id, Sloc (Id)); + Decl : Node_Id; + + begin + -- Make sure that the actual subtype doesn't generate + -- bogus freezing. + + Set_Must_Not_Freeze (Non_Freezing_Ref); + Decl := Build_Actual_Subtype (T, Non_Freezing_Ref); + Insert_Before_And_Analyze (N, Decl); + Set_Actual_Subtype (Id, Defining_Identifier (Decl)); + end; + else + Set_Actual_Subtype (Id, T); + end if; + + if Present (E) then + Error_Msg_N + ("initialization not allowed for `IN OUT` formals", N); + end if; + end if; + + end Analyze_Formal_Object_Declaration; + + ---------------------------------------------- + -- Analyze_Formal_Ordinary_Fixed_Point_Type -- + ---------------------------------------------- + + procedure Analyze_Formal_Ordinary_Fixed_Point_Type + (T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + Base : constant Entity_Id := + New_Internal_Entity + (E_Ordinary_Fixed_Point_Type, Current_Scope, Sloc (Def), 'G'); + begin + -- The semantic attributes are set for completeness only, their + -- values will never be used, because all properties of the type + -- are non-static. + + Enter_Name (T); + Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, Standard_Integer); + Set_RM_Size (T, RM_Size (Standard_Integer)); + Set_Small_Value (T, Ureal_1); + Set_Delta_Value (T, Ureal_1); + Set_Scalar_Range (T, + Make_Range (Loc, + Low_Bound => Make_Real_Literal (Loc, Ureal_1), + High_Bound => Make_Real_Literal (Loc, Ureal_1))); + + Set_Is_Generic_Type (Base); + Set_Etype (Base, Base); + Set_Size_Info (Base, Standard_Integer); + Set_RM_Size (Base, RM_Size (Standard_Integer)); + Set_Small_Value (Base, Ureal_1); + Set_Delta_Value (Base, Ureal_1); + Set_Scalar_Range (Base, Scalar_Range (T)); + Set_Parent (Base, Parent (Def)); + end Analyze_Formal_Ordinary_Fixed_Point_Type; + + ---------------------------- + -- Analyze_Formal_Package -- + ---------------------------- + + procedure Analyze_Formal_Package (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Formal : Entity_Id := Defining_Identifier (N); + Gen_Id : constant Node_Id := Name (N); + Gen_Decl : Node_Id; + Gen_Unit : Entity_Id; + New_N : Node_Id; + Parent_Installed : Boolean := False; + Renaming : Node_Id; + Parent_Instance : Entity_Id; + Renaming_In_Par : Entity_Id; + + begin + Text_IO_Kludge (Gen_Id); + + Check_Generic_Child_Unit (Gen_Id, Parent_Installed); + Gen_Unit := Entity (Gen_Id); + + if Ekind (Gen_Unit) /= E_Generic_Package then + Error_Msg_N ("expect generic package name", Gen_Id); + return; + + elsif Gen_Unit = Current_Scope then + Error_Msg_N + ("generic package cannot be used as a formal package of itself", + Gen_Id); + return; + end if; + + -- Check for a formal package that is a package renaming. + + if Present (Renamed_Object (Gen_Unit)) then + Gen_Unit := Renamed_Object (Gen_Unit); + end if; + + -- The formal package is treated like a regular instance, but only + -- the specification needs to be instantiated, to make entities visible. + + if not Box_Present (N) then + Hidden_Entities := New_Elmt_List; + Analyze_Package_Instantiation (N); + + if Parent_Installed then + Remove_Parent; + end if; + + else + -- If there are no generic associations, the generic parameters + -- appear as local entities and are instantiated like them. We copy + -- the generic package declaration as if it were an instantiation, + -- and analyze it like a regular package, except that we treat the + -- formals as additional visible components. + + Save_Env (Gen_Unit, Formal); + + Gen_Decl := Unit_Declaration_Node (Gen_Unit); + + if In_Extended_Main_Source_Unit (N) then + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + end if; + + New_N := + Copy_Generic_Node + (Original_Node (Gen_Decl), Empty, Instantiating => True); + Set_Defining_Unit_Name (Specification (New_N), Formal); + Rewrite (N, New_N); + + Enter_Name (Formal); + Set_Ekind (Formal, E_Generic_Package); + Set_Etype (Formal, Standard_Void_Type); + Set_Inner_Instances (Formal, New_Elmt_List); + New_Scope (Formal); + + -- Within the formal, the name of the generic package is a renaming + -- of the formal (as for a regular instantiation). + + Renaming := Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, Chars (Gen_Unit)), + Name => New_Reference_To (Formal, Loc)); + + if Present (Visible_Declarations (Specification (N))) then + Prepend (Renaming, To => Visible_Declarations (Specification (N))); + elsif Present (Private_Declarations (Specification (N))) then + Prepend (Renaming, To => Private_Declarations (Specification (N))); + end if; + + if Is_Child_Unit (Gen_Unit) + and then Parent_Installed + then + -- Similarly, we have to make the name of the formal visible in + -- the parent instance, to resolve properly fully qualified names + -- that may appear in the generic unit. The parent instance has + -- been placed on the scope stack ahead of the current scope. + + Parent_Instance := Scope_Stack.Table (Scope_Stack.Last - 1).Entity; + + Renaming_In_Par := + Make_Defining_Identifier (Loc, Chars (Gen_Unit)); + Set_Ekind (Renaming_In_Par, E_Package); + Set_Etype (Renaming_In_Par, Standard_Void_Type); + Set_Scope (Renaming_In_Par, Parent_Instance); + Set_Parent (Renaming_In_Par, Parent (Formal)); + Set_Renamed_Object (Renaming_In_Par, Formal); + Append_Entity (Renaming_In_Par, Parent_Instance); + end if; + + Analyze_Generic_Formal_Part (N); + Analyze (Specification (N)); + End_Package_Scope (Formal); + + if Parent_Installed then + Remove_Parent; + end if; + + Restore_Env; + + -- Inside the generic unit, the formal package is a regular + -- package, but no body is needed for it. Note that after + -- instantiation, the defining_unit_name we need is in the + -- new tree and not in the original. (see Package_Instantiation). + -- A generic formal package is an instance, and can be used as + -- an actual for an inner instance. Mark its generic parent. + + Set_Ekind (Formal, E_Package); + Set_Generic_Parent (Specification (N), Gen_Unit); + Set_Has_Completion (Formal, True); + end if; + end Analyze_Formal_Package; + + --------------------------------- + -- Analyze_Formal_Private_Type -- + --------------------------------- + + procedure Analyze_Formal_Private_Type + (N : Node_Id; + T : Entity_Id; + Def : Node_Id) + is + begin + New_Private_Type (N, T, Def); + + -- Set the size to an arbitrary but legal value. + + Set_Size_Info (T, Standard_Integer); + Set_RM_Size (T, RM_Size (Standard_Integer)); + end Analyze_Formal_Private_Type; + + ---------------------------------------- + -- Analyze_Formal_Signed_Integer_Type -- + ---------------------------------------- + + procedure Analyze_Formal_Signed_Integer_Type + (T : Entity_Id; + Def : Node_Id) + is + Base : constant Entity_Id := + New_Internal_Entity + (E_Signed_Integer_Type, Current_Scope, Sloc (Def), 'G'); + + begin + Enter_Name (T); + + Set_Ekind (T, E_Signed_Integer_Subtype); + Set_Etype (T, Base); + Set_Size_Info (T, Standard_Integer); + Set_RM_Size (T, RM_Size (Standard_Integer)); + Set_Scalar_Range (T, Scalar_Range (Standard_Integer)); + + Set_Is_Generic_Type (Base); + Set_Size_Info (Base, Standard_Integer); + Set_RM_Size (Base, RM_Size (Standard_Integer)); + Set_Etype (Base, Base); + Set_Scalar_Range (Base, Scalar_Range (Standard_Integer)); + Set_Parent (Base, Parent (Def)); + end Analyze_Formal_Signed_Integer_Type; + + ------------------------------- + -- Analyze_Formal_Subprogram -- + ------------------------------- + + procedure Analyze_Formal_Subprogram (N : Node_Id) is + Spec : constant Node_Id := Specification (N); + Def : constant Node_Id := Default_Name (N); + Nam : constant Entity_Id := Defining_Unit_Name (Spec); + Subp : Entity_Id; + + begin + if Nkind (Nam) = N_Defining_Program_Unit_Name then + Error_Msg_N ("name of formal subprogram must be a direct name", Nam); + return; + end if; + + Analyze_Subprogram_Declaration (N); + Set_Is_Formal_Subprogram (Nam); + Set_Has_Completion (Nam); + + -- Default name is resolved at the point of instantiation + + if Box_Present (N) then + null; + + -- Else default is bound at the point of generic declaration + + elsif Present (Def) then + if Nkind (Def) = N_Operator_Symbol then + Find_Direct_Name (Def); + + elsif Nkind (Def) /= N_Attribute_Reference then + Analyze (Def); + + else + -- For an attribute reference, analyze the prefix and verify + -- that it has the proper profile for the subprogram. + + Analyze (Prefix (Def)); + Valid_Default_Attribute (Nam, Def); + return; + end if; + + -- Default name may be overloaded, in which case the interpretation + -- with the correct profile must be selected, as for a renaming. + + if Etype (Def) = Any_Type then + return; + + elsif Nkind (Def) = N_Selected_Component then + Subp := Entity (Selector_Name (Def)); + + if Ekind (Subp) /= E_Entry then + Error_Msg_N ("expect valid subprogram name as default", Def); + return; + end if; + + elsif Nkind (Def) = N_Indexed_Component then + + if Nkind (Prefix (Def)) /= N_Selected_Component then + Error_Msg_N ("expect valid subprogram name as default", Def); + return; + + else + Subp := Entity (Selector_Name (Prefix (Def))); + + if Ekind (Subp) /= E_Entry_Family then + Error_Msg_N ("expect valid subprogram name as default", Def); + return; + end if; + end if; + + elsif Nkind (Def) = N_Character_Literal then + + -- Needs some type checks: subprogram should be parameterless??? + + Resolve (Def, (Etype (Nam))); + + elsif (not Is_Entity_Name (Def) + or else not Is_Overloadable (Entity (Def))) + then + Error_Msg_N ("expect valid subprogram name as default", Def); + return; + + elsif not Is_Overloaded (Def) then + Subp := Entity (Def); + + if Subp = Nam then + Error_Msg_N ("premature usage of formal subprogram", Def); + + elsif not Entity_Matches_Spec (Subp, Nam) then + Error_Msg_N ("no visible entity matches specification", Def); + end if; + + else + declare + I : Interp_Index; + I1 : Interp_Index := 0; + It : Interp; + It1 : Interp; + + begin + Subp := Any_Id; + Get_First_Interp (Def, I, It); + while Present (It.Nam) loop + + if Entity_Matches_Spec (It.Nam, Nam) then + if Subp /= Any_Id then + It1 := Disambiguate (Def, I1, I, Etype (Subp)); + + if It1 = No_Interp then + Error_Msg_N ("ambiguous default subprogram", Def); + else + Subp := It1.Nam; + end if; + + exit; + + else + I1 := I; + Subp := It.Nam; + end if; + end if; + + Get_Next_Interp (I, It); + end loop; + end; + + if Subp /= Any_Id then + Set_Entity (Def, Subp); + + if Subp = Nam then + Error_Msg_N ("premature usage of formal subprogram", Def); + + elsif Ekind (Subp) /= E_Operator then + Check_Mode_Conformant (Subp, Nam); + end if; + + else + Error_Msg_N ("no visible subprogram matches specification", N); + end if; + end if; + end if; + end Analyze_Formal_Subprogram; + + ------------------------------------- + -- Analyze_Formal_Type_Declaration -- + ------------------------------------- + + procedure Analyze_Formal_Type_Declaration (N : Node_Id) is + Def : constant Node_Id := Formal_Type_Definition (N); + T : Entity_Id; + + begin + T := Defining_Identifier (N); + + if Present (Discriminant_Specifications (N)) + and then Nkind (Def) /= N_Formal_Private_Type_Definition + then + Error_Msg_N + ("discriminants not allowed for this formal type", + Defining_Identifier (First (Discriminant_Specifications (N)))); + end if; + + -- Enter the new name, and branch to specific routine. + + case Nkind (Def) is + when N_Formal_Private_Type_Definition + => Analyze_Formal_Private_Type (N, T, Def); + + when N_Formal_Derived_Type_Definition + => Analyze_Formal_Derived_Type (N, T, Def); + + when N_Formal_Discrete_Type_Definition + => Analyze_Formal_Discrete_Type (T, Def); + + when N_Formal_Signed_Integer_Type_Definition + => Analyze_Formal_Signed_Integer_Type (T, Def); + + when N_Formal_Modular_Type_Definition + => Analyze_Formal_Modular_Type (T, Def); + + when N_Formal_Floating_Point_Definition + => Analyze_Formal_Floating_Type (T, Def); + + when N_Formal_Ordinary_Fixed_Point_Definition + => Analyze_Formal_Ordinary_Fixed_Point_Type (T, Def); + + when N_Formal_Decimal_Fixed_Point_Definition + => Analyze_Formal_Decimal_Fixed_Point_Type (T, Def); + + when N_Array_Type_Definition + => Analyze_Formal_Array_Type (T, Def); + + when N_Access_To_Object_Definition | + N_Access_Function_Definition | + N_Access_Procedure_Definition + => Analyze_Generic_Access_Type (T, Def); + + when others => + raise Program_Error; + + end case; + + Set_Is_Generic_Type (T); + + end Analyze_Formal_Type_Declaration; + + ------------------------------------ + -- Analyze_Function_Instantiation -- + ------------------------------------ + + procedure Analyze_Function_Instantiation (N : Node_Id) is + begin + Analyze_Subprogram_Instantiation (N, E_Function); + end Analyze_Function_Instantiation; + + --------------------------------- + -- Analyze_Generic_Access_Type -- + --------------------------------- + + procedure Analyze_Generic_Access_Type (T : Entity_Id; Def : Node_Id) is + begin + Enter_Name (T); + + if Nkind (Def) = N_Access_To_Object_Definition then + Access_Type_Declaration (T, Def); + + if Is_Incomplete_Or_Private_Type (Designated_Type (T)) + and then No (Full_View (Designated_Type (T))) + and then not Is_Generic_Type (Designated_Type (T)) + then + Error_Msg_N ("premature usage of incomplete type", Def); + + elsif Is_Internal (Designated_Type (T)) then + Error_Msg_N + ("only a subtype mark is allowed in a formal", Def); + end if; + + else + Access_Subprogram_Declaration (T, Def); + end if; + end Analyze_Generic_Access_Type; + + --------------------------------- + -- Analyze_Generic_Formal_Part -- + --------------------------------- + + procedure Analyze_Generic_Formal_Part (N : Node_Id) is + Gen_Parm_Decl : Node_Id; + + begin + -- The generic formals are processed in the scope of the generic + -- unit, where they are immediately visible. The scope is installed + -- by the caller. + + Gen_Parm_Decl := First (Generic_Formal_Declarations (N)); + + while Present (Gen_Parm_Decl) loop + Analyze (Gen_Parm_Decl); + Next (Gen_Parm_Decl); + end loop; + end Analyze_Generic_Formal_Part; + + ------------------------------------------ + -- Analyze_Generic_Package_Declaration -- + ------------------------------------------ + + procedure Analyze_Generic_Package_Declaration (N : Node_Id) is + Id : Entity_Id; + New_N : Node_Id; + Save_Parent : Node_Id; + + begin + -- Create copy of generic unit, and save for instantiation. + -- If the unit is a child unit, do not copy the specifications + -- for the parent, which are not part of the generic tree. + + Save_Parent := Parent_Spec (N); + Set_Parent_Spec (N, Empty); + + New_N := Copy_Generic_Node (N, Empty, Instantiating => False); + Set_Parent_Spec (New_N, Save_Parent); + Rewrite (N, New_N); + Id := Defining_Entity (N); + Generate_Definition (Id); + + -- Expansion is not applied to generic units. + + Start_Generic; + + Enter_Name (Id); + Set_Ekind (Id, E_Generic_Package); + Set_Etype (Id, Standard_Void_Type); + New_Scope (Id); + Enter_Generic_Scope (Id); + Set_Inner_Instances (Id, New_Elmt_List); + + Set_Categorization_From_Pragmas (N); + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + + -- For a library unit, we have reconstructed the entity for the + -- unit, and must reset it in the library tables. + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Cunit_Entity (Current_Sem_Unit, Id); + end if; + + Analyze_Generic_Formal_Part (N); + + -- After processing the generic formals, analysis proceeds + -- as for a non-generic package. + + Analyze (Specification (N)); + + Validate_Categorization_Dependency (N, Id); + + End_Generic; + + End_Package_Scope (Id); + Exit_Generic_Scope (Id); + + if Nkind (Parent (N)) /= N_Compilation_Unit then + Move_Freeze_Nodes (Id, N, Visible_Declarations (Specification (N))); + Move_Freeze_Nodes (Id, N, Private_Declarations (Specification (N))); + Move_Freeze_Nodes (Id, N, Generic_Formal_Declarations (N)); + + else + Set_Body_Required (Parent (N), Unit_Requires_Body (Id)); + Validate_RT_RAT_Component (N); + end if; + + end Analyze_Generic_Package_Declaration; + + -------------------------------------------- + -- Analyze_Generic_Subprogram_Declaration -- + -------------------------------------------- + + procedure Analyze_Generic_Subprogram_Declaration (N : Node_Id) is + Spec : Node_Id; + Id : Entity_Id; + Formals : List_Id; + New_N : Node_Id; + Save_Parent : Node_Id; + + begin + -- Create copy of generic unit,and save for instantiation. + -- If the unit is a child unit, do not copy the specifications + -- for the parent, which are not part of the generic tree. + + Save_Parent := Parent_Spec (N); + Set_Parent_Spec (N, Empty); + + New_N := Copy_Generic_Node (N, Empty, Instantiating => False); + Set_Parent_Spec (New_N, Save_Parent); + Rewrite (N, New_N); + + Spec := Specification (N); + Id := Defining_Entity (Spec); + Generate_Definition (Id); + + if Nkind (Id) = N_Defining_Operator_Symbol then + Error_Msg_N + ("operator symbol not allowed for generic subprogram", Id); + end if; + + Start_Generic; + + Enter_Name (Id); + + New_Scope (Id); + Set_Inner_Instances (Id, New_Elmt_List); + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + + Analyze_Generic_Formal_Part (N); + + Formals := Parameter_Specifications (Spec); + + if Present (Formals) then + Process_Formals (Id, Formals, Spec); + end if; + + if Nkind (Spec) = N_Function_Specification then + Set_Ekind (Id, E_Generic_Function); + Find_Type (Subtype_Mark (Spec)); + Set_Etype (Id, Entity (Subtype_Mark (Spec))); + else + Set_Ekind (Id, E_Generic_Procedure); + Set_Etype (Id, Standard_Void_Type); + end if; + + -- For a library unit, we have reconstructed the entity for the + -- unit, and must reset it in the library tables. We also need + -- to make sure that Body_Required is set properly in the original + -- compilation unit node. + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Cunit_Entity (Current_Sem_Unit, Id); + Set_Body_Required (Parent (N), Unit_Requires_Body (Id)); + end if; + + Set_Categorization_From_Pragmas (N); + Validate_Categorization_Dependency (N, Id); + + Save_Global_References (Original_Node (N)); + + End_Generic; + End_Scope; + + end Analyze_Generic_Subprogram_Declaration; + + ----------------------------------- + -- Analyze_Package_Instantiation -- + ----------------------------------- + + -- Note: this procedure is also used for formal package declarations, + -- in which case the argument N is an N_Formal_Package_Declaration + -- node. This should really be noted in the spec! ??? + + procedure Analyze_Package_Instantiation (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Gen_Id : constant Node_Id := Name (N); + + Act_Decl : Node_Id; + Act_Decl_Name : Node_Id; + Act_Decl_Id : Entity_Id; + Act_Spec : Node_Id; + Act_Tree : Node_Id; + + Gen_Decl : Node_Id; + Gen_Unit : Entity_Id; + + Is_Actual_Pack : Boolean := Is_Internal (Defining_Entity (N)); + Parent_Installed : Boolean := False; + Renaming_List : List_Id; + Unit_Renaming : Node_Id; + Needs_Body : Boolean; + Inline_Now : Boolean := False; + + procedure Delay_Descriptors (E : Entity_Id); + -- Delay generation of subprogram descriptors for given entity + + function Might_Inline_Subp return Boolean; + -- If inlining is active and the generic contains inlined subprograms, + -- we instantiate the body. This may cause superfluous instantiations, + -- but it is simpler than detecting the need for the body at the point + -- of inlining, when the context of the instance is not available. + + ----------------------- + -- Delay_Descriptors -- + ----------------------- + + procedure Delay_Descriptors (E : Entity_Id) is + begin + if not Delay_Subprogram_Descriptors (E) then + Set_Delay_Subprogram_Descriptors (E); + Pending_Descriptor.Increment_Last; + Pending_Descriptor.Table (Pending_Descriptor.Last) := E; + end if; + end Delay_Descriptors; + + ----------------------- + -- Might_Inline_Subp -- + ----------------------- + + function Might_Inline_Subp return Boolean is + E : Entity_Id; + + begin + if not Inline_Processing_Required then + return False; + + else + E := First_Entity (Gen_Unit); + + while Present (E) loop + + if Is_Subprogram (E) + and then Is_Inlined (E) + then + return True; + end if; + + Next_Entity (E); + end loop; + end if; + + return False; + end Might_Inline_Subp; + + -- Start of processing for Analyze_Package_Instantiation + + begin + -- Very first thing: apply the special kludge for Text_IO processing + -- in case we are instantiating one of the children of [Wide_]Text_IO. + + Text_IO_Kludge (Name (N)); + + -- Make node global for error reporting. + + Instantiation_Node := N; + + -- Case of instantiation of a generic package + + if Nkind (N) = N_Package_Instantiation then + Act_Decl_Id := New_Copy (Defining_Entity (N)); + Set_Comes_From_Source (Act_Decl_Id, True); + + if Nkind (Defining_Unit_Name (N)) = N_Defining_Program_Unit_Name then + Act_Decl_Name := + Make_Defining_Program_Unit_Name (Loc, + Name => New_Copy_Tree (Name (Defining_Unit_Name (N))), + Defining_Identifier => Act_Decl_Id); + else + Act_Decl_Name := Act_Decl_Id; + end if; + + -- Case of instantiation of a formal package + + else + Act_Decl_Id := Defining_Identifier (N); + Act_Decl_Name := Act_Decl_Id; + end if; + + Generate_Definition (Act_Decl_Id); + Pre_Analyze_Actuals (N); + + Check_Generic_Child_Unit (Gen_Id, Parent_Installed); + Gen_Unit := Entity (Gen_Id); + + -- Verify that it is the name of a generic package + + if Etype (Gen_Unit) = Any_Type then + return; + + elsif Ekind (Gen_Unit) /= E_Generic_Package then + Error_Msg_N + ("expect name of generic package in instantiation", Gen_Id); + return; + end if; + + if In_Extended_Main_Source_Unit (N) then + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + + if Present (Renamed_Object (Gen_Unit)) then + Set_Is_Instantiated (Renamed_Object (Gen_Unit)); + Generate_Reference (Renamed_Object (Gen_Unit), N); + end if; + end if; + + if Nkind (Gen_Id) = N_Identifier + and then Chars (Gen_Unit) = Chars (Defining_Entity (N)) + then + Error_Msg_NE + ("& is hidden within declaration of instance", Gen_Id, Gen_Unit); + + elsif Nkind (Gen_Id) = N_Expanded_Name + and then Is_Child_Unit (Gen_Unit) + and then Nkind (Prefix (Gen_Id)) = N_Identifier + and then Chars (Act_Decl_Id) = Chars (Prefix (Gen_Id)) + then + Error_Msg_N + ("& is hidden within declaration of instance ", Prefix (Gen_Id)); + end if; + + -- If renaming, indicate this is an instantiation of renamed unit. + + if Present (Renamed_Object (Gen_Unit)) + and then Ekind (Renamed_Object (Gen_Unit)) = E_Generic_Package + then + Gen_Unit := Renamed_Object (Gen_Unit); + Set_Entity (Gen_Id, Gen_Unit); + end if; + + -- Verify that there are no circular instantiations. + + if In_Open_Scopes (Gen_Unit) then + Error_Msg_NE ("instantiation of & within itself", N, Gen_Unit); + return; + + elsif Contains_Instance_Of (Gen_Unit, Current_Scope, Gen_Id) then + Error_Msg_Node_2 := Current_Scope; + Error_Msg_NE + ("circular Instantiation: & instantiated in &!", N, Gen_Unit); + Circularity_Detected := True; + return; + + else + Save_Env (Gen_Unit, Act_Decl_Id); + Gen_Decl := Unit_Declaration_Node (Gen_Unit); + + -- Initialize renamings map, for error checking, and the list + -- that holds private entities whose views have changed between + -- generic definition and instantiation. If this is the instance + -- created to validate an actual package, the instantiation + -- environment is that of the enclosing instance. + + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + + Create_Instantiation_Source (N, Gen_Unit, S_Adjustment); + + -- Copy original generic tree, to produce text for instantiation. + + Act_Tree := + Copy_Generic_Node + (Original_Node (Gen_Decl), Empty, Instantiating => True); + + Act_Spec := Specification (Act_Tree); + + -- If this is the instance created to validate an actual package, + -- only the formals matter, do not examine the package spec itself. + + if Is_Actual_Pack then + Set_Visible_Declarations (Act_Spec, New_List); + Set_Private_Declarations (Act_Spec, New_List); + end if; + + Renaming_List := + Analyze_Associations + (N, + Generic_Formal_Declarations (Act_Tree), + Generic_Formal_Declarations (Gen_Decl)); + + Set_Defining_Unit_Name (Act_Spec, Act_Decl_Name); + Set_Is_Generic_Instance (Act_Decl_Id); + + Set_Generic_Parent (Act_Spec, Gen_Unit); + + -- References to the generic in its own declaration or its body + -- are references to the instance. Add a renaming declaration for + -- the generic unit itself. This declaration, as well as the renaming + -- declarations for the generic formals, must remain private to the + -- unit: the formals, because this is the language semantics, and + -- the unit because its use is an artifact of the implementation. + + Unit_Renaming := + Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, Chars (Gen_Unit)), + Name => New_Reference_To (Act_Decl_Id, Loc)); + + Append (Unit_Renaming, Renaming_List); + + -- The renaming declarations are the first local declarations of + -- the new unit. + + if Is_Non_Empty_List (Visible_Declarations (Act_Spec)) then + Insert_List_Before + (First (Visible_Declarations (Act_Spec)), Renaming_List); + else + Set_Visible_Declarations (Act_Spec, Renaming_List); + end if; + + Act_Decl := + Make_Package_Declaration (Loc, + Specification => Act_Spec); + + -- Save the instantiation node, for subsequent instantiation + -- of the body, if there is one and we are generating code for + -- the current unit. Mark the unit as having a body, to avoid + -- a premature error message. + + -- We instantiate the body if we are generating code, if we are + -- generating cross-reference information, or if we are building + -- trees for ASIS use. + + declare + Enclosing_Body_Present : Boolean := False; + Scop : Entity_Id; + + begin + if Scope (Gen_Unit) /= Standard_Standard + and then not Is_Child_Unit (Gen_Unit) + then + Scop := Scope (Gen_Unit); + + while Present (Scop) + and then Scop /= Standard_Standard + loop + if Unit_Requires_Body (Scop) then + Enclosing_Body_Present := True; + exit; + end if; + + Scop := Scope (Scop); + end loop; + end if; + + -- If front-end inlining is enabled, and this is a unit for which + -- code will be generated, we instantiate the body at once. + -- This is done if the instance is not the main unit, and if the + -- generic is not a child unit, to avoid scope problems. + + if Front_End_Inlining + and then Expander_Active + and then not Is_Child_Unit (Gen_Unit) + and then Is_In_Main_Unit (N) + and then Nkind (Parent (N)) /= N_Compilation_Unit + and then Might_Inline_Subp + then + Inline_Now := True; + end if; + + Needs_Body := + (Unit_Requires_Body (Gen_Unit) + or else Enclosing_Body_Present + or else Present (Corresponding_Body (Gen_Decl))) + and then (Is_In_Main_Unit (N) + or else Might_Inline_Subp) + and then not Is_Actual_Pack + and then not Inline_Now + + and then (Operating_Mode = Generate_Code + or else (Operating_Mode = Check_Semantics + and then Tree_Output)); + + -- If front_end_inlining is enabled, do not instantiate a + -- body if within a generic context. + + if Front_End_Inlining + and then not Expander_Active + then + Needs_Body := False; + end if; + + end; + + -- If we are generating the calling stubs from the instantiation + -- of a generic RCI package, we will not use the body of the + -- generic package. + + if Distribution_Stub_Mode = Generate_Caller_Stub_Body + and then Is_Compilation_Unit (Defining_Entity (N)) + then + Needs_Body := False; + end if; + + if Needs_Body then + + -- Here is a defence against a ludicrous number of instantiations + -- caused by a circular set of instantiation attempts. + + if Pending_Instantiations.Last > + Hostparm.Max_Instantiations + then + Error_Msg_N ("too many instantiations", N); + raise Unrecoverable_Error; + end if; + + -- Indicate that the enclosing scopes contain an instantiation, + -- and that cleanup actions should be delayed until after the + -- instance body is expanded. + + Check_Forward_Instantiation (N, Gen_Decl); + if Nkind (N) = N_Package_Instantiation then + declare + Enclosing_Master : Entity_Id := Current_Scope; + + begin + while Enclosing_Master /= Standard_Standard loop + + if Ekind (Enclosing_Master) = E_Package then + if Is_Compilation_Unit (Enclosing_Master) then + if In_Package_Body (Enclosing_Master) then + Delay_Descriptors + (Body_Entity (Enclosing_Master)); + else + Delay_Descriptors + (Enclosing_Master); + end if; + + exit; + + else + Enclosing_Master := Scope (Enclosing_Master); + end if; + + elsif Ekind (Enclosing_Master) = E_Generic_Package then + Enclosing_Master := Scope (Enclosing_Master); + + elsif Ekind (Enclosing_Master) = E_Generic_Function + or else Ekind (Enclosing_Master) = E_Generic_Procedure + or else Ekind (Enclosing_Master) = E_Void + then + -- Cleanup actions will eventually be performed on + -- the enclosing instance, if any. enclosing scope + -- is void in the formal part of a generic subp. + + exit; + + else + if Ekind (Enclosing_Master) = E_Entry + and then + Ekind (Scope (Enclosing_Master)) = E_Protected_Type + then + Enclosing_Master := + Protected_Body_Subprogram (Enclosing_Master); + end if; + + Set_Delay_Cleanups (Enclosing_Master); + + while Ekind (Enclosing_Master) = E_Block loop + Enclosing_Master := Scope (Enclosing_Master); + end loop; + + if Is_Subprogram (Enclosing_Master) then + Delay_Descriptors (Enclosing_Master); + + elsif Is_Task_Type (Enclosing_Master) then + declare + TBP : constant Node_Id := + Get_Task_Body_Procedure + (Enclosing_Master); + + begin + if Present (TBP) then + Delay_Descriptors (TBP); + Set_Delay_Cleanups (TBP); + end if; + end; + end if; + + exit; + end if; + end loop; + end; + + -- Make entry in table + + Pending_Instantiations.Increment_Last; + Pending_Instantiations.Table (Pending_Instantiations.Last) := + (N, Act_Decl, Expander_Active, Current_Sem_Unit); + end if; + end if; + + Set_Categorization_From_Pragmas (Act_Decl); + + if Parent_Installed then + Hide_Current_Scope; + end if; + + Set_Instance_Spec (N, Act_Decl); + + -- Case of not a compilation unit + + if Nkind (Parent (N)) /= N_Compilation_Unit then + Mark_Rewrite_Insertion (Act_Decl); + Insert_Before (N, Act_Decl); + Analyze (Act_Decl); + + -- Case of compilation unit that is generic instantiation + + -- Place declaration on current node so context is complete + -- for analysis (including nested instantiations). + + else + if Cunit_Entity (Current_Sem_Unit) = Defining_Entity (N) then + + -- The entity for the current unit is the newly created one, + -- and all semantic information is attached to it. + + Set_Cunit_Entity (Current_Sem_Unit, Act_Decl_Id); + + -- If this is the main unit, replace the main entity as well. + + if Current_Sem_Unit = Main_Unit then + Main_Unit_Entity := Act_Decl_Id; + end if; + end if; + + Set_Unit (Parent (N), Act_Decl); + Set_Parent_Spec (Act_Decl, Parent_Spec (N)); + Analyze (Act_Decl); + Set_Unit (Parent (N), N); + Set_Body_Required (Parent (N), False); + + -- We never need elaboration checks on instantiations, since + -- by definition, the body instantiation is elaborated at the + -- same time as the spec instantiation. + + Set_Suppress_Elaboration_Warnings (Act_Decl_Id); + Set_Suppress_Elaboration_Checks (Act_Decl_Id); + end if; + + Check_Elab_Instantiation (N); + + if ABE_Is_Certain (N) and then Needs_Body then + Pending_Instantiations.Decrement_Last; + end if; + Check_Hidden_Child_Unit (N, Gen_Unit, Act_Decl_Id); + + Set_First_Private_Entity (Defining_Unit_Name (Unit_Renaming), + First_Private_Entity (Act_Decl_Id)); + + if Nkind (Parent (N)) = N_Compilation_Unit + and then not Needs_Body + then + Rewrite (N, Act_Decl); + end if; + + if Present (Corresponding_Body (Gen_Decl)) + or else Unit_Requires_Body (Gen_Unit) + then + Set_Has_Completion (Act_Decl_Id); + end if; + + Check_Formal_Packages (Act_Decl_Id); + + Restore_Private_Views (Act_Decl_Id); + + if not Generic_Separately_Compiled (Gen_Unit) then + Inherit_Context (Gen_Decl, N); + end if; + + if Parent_Installed then + Remove_Parent; + end if; + + Restore_Env; + end if; + + Validate_Categorization_Dependency (N, Act_Decl_Id); + + -- Check restriction, but skip this if something went wrong in + -- the above analysis, indicated by Act_Decl_Id being void. + + if Ekind (Act_Decl_Id) /= E_Void + and then not Is_Library_Level_Entity (Act_Decl_Id) + then + Check_Restriction (No_Local_Allocators, N); + end if; + + if Inline_Now then + Inline_Instance_Body (N, Gen_Unit, Act_Decl); + end if; + + exception + when Instantiation_Error => + if Parent_Installed then + Remove_Parent; + end if; + + end Analyze_Package_Instantiation; + + --------------------------- + -- Inline_Instance_Body -- + --------------------------- + + procedure Inline_Instance_Body + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl : Node_Id) + is + Vis : Boolean; + Gen_Comp : constant Entity_Id := + Cunit_Entity (Get_Source_Unit (Gen_Unit)); + Curr_Comp : constant Node_Id := Cunit (Current_Sem_Unit); + Curr_Scope : Entity_Id := Empty; + Curr_Unit : constant Entity_Id := + Cunit_Entity (Current_Sem_Unit); + Removed : Boolean := False; + Num_Scopes : Int := 0; + Use_Clauses : array (1 .. Scope_Stack.Last) of Node_Id; + Instances : array (1 .. Scope_Stack.Last) of Entity_Id; + Inner_Scopes : array (1 .. Scope_Stack.Last) of Entity_Id; + Num_Inner : Int := 0; + N_Instances : Int := 0; + S : Entity_Id; + + begin + -- Case of generic unit defined in another unit + + if Gen_Comp /= Cunit_Entity (Current_Sem_Unit) then + Vis := Is_Immediately_Visible (Gen_Comp); + + S := Current_Scope; + + while Present (S) + and then S /= Standard_Standard + loop + Num_Scopes := Num_Scopes + 1; + + Use_Clauses (Num_Scopes) := + (Scope_Stack.Table + (Scope_Stack.Last - Num_Scopes + 1). + First_Use_Clause); + End_Use_Clauses (Use_Clauses (Num_Scopes)); + + exit when Is_Generic_Instance (S) + and then (In_Package_Body (S) + or else Ekind (S) = E_Procedure + or else Ekind (S) = E_Function); + S := Scope (S); + end loop; + + -- Find and save all enclosing instances. + + S := Current_Scope; + + while Present (S) + and then S /= Standard_Standard + loop + if Is_Generic_Instance (S) then + N_Instances := N_Instances + 1; + Instances (N_Instances) := S; + end if; + + S := Scope (S); + end loop; + + -- Remove context of current compilation unit, unless we + -- are within a nested package instantiation, in which case + -- the context has been removed previously. + -- If current scope is the body of a child unit, remove context + -- of spec as well. + + S := Current_Scope; + + while Present (S) + and then S /= Standard_Standard + loop + exit when Is_Generic_Instance (S) + and then In_Package_Body (S); + + if S = Curr_Unit + or else (Ekind (Curr_Unit) = E_Package_Body + and then S = Spec_Entity (Curr_Unit)) + then + Removed := True; + + if Is_Child_Unit (S) then + -- Remove child unit from stack, as well as inner scopes. + -- Removing its context of child unit will remove parent + -- units as well. + + while Current_Scope /= S loop + Num_Inner := Num_Inner + 1; + Inner_Scopes (Num_Inner) := Current_Scope; + Pop_Scope; + end loop; + + Pop_Scope; + Remove_Context (Curr_Comp); + Curr_Scope := S; + + else + Remove_Context (Curr_Comp); + end if; + + if Ekind (Curr_Unit) = E_Package_Body then + Remove_Context (Library_Unit (Curr_Comp)); + end if; + end if; + + S := Scope (S); + end loop; + + Instantiate_Package_Body + ((N, Act_Decl, Expander_Active, Current_Sem_Unit)); + + -- Restore context. + + Set_Is_Immediately_Visible (Gen_Comp, Vis); + + -- Reset Generic_Instance flag so that use clauses can be installed + -- in the proper order. (See Use_One_Package for effect of enclosing + -- instances on processing of use clauses). + + for J in 1 .. N_Instances loop + Set_Is_Generic_Instance (Instances (J), False); + end loop; + + if Removed then + -- Make local entities not visible, so that when the context of + -- unit is restored, there are not spurious hidings of use- + -- visible entities (which appear in the environment before the + -- current scope). + + if Current_Scope /= Standard_Standard then + S := First_Entity (Current_Scope); + + while Present (S) loop + if Is_Overloadable (S) then + Set_Is_Immediately_Visible (S, False); + end if; + + Next_Entity (S); + end loop; + end if; + + Install_Context (Curr_Comp); + + if Current_Scope /= Standard_Standard then + S := First_Entity (Current_Scope); + + while Present (S) loop + if Is_Overloadable (S) then + Set_Is_Immediately_Visible (S); + end if; + + Next_Entity (S); + end loop; + end if; + + if Present (Curr_Scope) + and then Is_Child_Unit (Curr_Scope) + then + New_Scope (Curr_Scope); + Set_Is_Immediately_Visible (Curr_Scope); + + -- Finally, restore inner scopes as well. + + for J in reverse 1 .. Num_Inner loop + New_Scope (Inner_Scopes (J)); + end loop; + end if; + end if; + + for J in reverse 1 .. Num_Scopes loop + Install_Use_Clauses (Use_Clauses (J)); + end loop; + + for J in 1 .. N_Instances loop + Set_Is_Generic_Instance (Instances (J), True); + end loop; + + -- If generic unit is in current unit, current context is correct. + + else + Instantiate_Package_Body + ((N, Act_Decl, Expander_Active, Current_Sem_Unit)); + end if; + end Inline_Instance_Body; + + ------------------------------------- + -- Analyze_Procedure_Instantiation -- + ------------------------------------- + + procedure Analyze_Procedure_Instantiation (N : Node_Id) is + begin + Analyze_Subprogram_Instantiation (N, E_Procedure); + end Analyze_Procedure_Instantiation; + + -------------------------------------- + -- Analyze_Subprogram_Instantiation -- + -------------------------------------- + + procedure Analyze_Subprogram_Instantiation + (N : Node_Id; + K : Entity_Kind) + is + Loc : constant Source_Ptr := Sloc (N); + Gen_Id : constant Node_Id := Name (N); + + Act_Decl_Id : Entity_Id; + Anon_Id : Entity_Id := + Make_Defining_Identifier + (Sloc (Defining_Entity (N)), + New_External_Name + (Chars (Defining_Entity (N)), 'R')); + Act_Decl : Node_Id; + Act_Spec : Node_Id; + Act_Tree : Node_Id; + + Gen_Unit : Entity_Id; + Gen_Decl : Node_Id; + Pack_Id : Entity_Id; + Parent_Installed : Boolean := False; + Renaming_List : List_Id; + Spec : Node_Id; + + procedure Analyze_Instance_And_Renamings; + -- The instance must be analyzed in a context that includes the + -- mappings of generic parameters into actuals. We create a package + -- declaration for this purpose, and a subprogram with an internal + -- name within the package. The subprogram instance is simply an + -- alias for the internal subprogram, declared in the current scope. + + ------------------------------------ + -- Analyze_Instance_And_Renamings -- + ------------------------------------ + + procedure Analyze_Instance_And_Renamings is + Def_Ent : constant Entity_Id := Defining_Entity (N); + Pack_Decl : Node_Id; + + begin + if Nkind (Parent (N)) = N_Compilation_Unit then + + -- For the case of a compilation unit, the container package + -- has the same name as the instantiation, to insure that the + -- binder calls the elaboration procedure with the right name. + -- Copy the entity of the instance, which may have compilation + -- level flags (eg. is_child_unit) set. + + Pack_Id := New_Copy (Def_Ent); + + else + -- Otherwise we use the name of the instantiation concatenated + -- with its source position to ensure uniqueness if there are + -- several instantiations with the same name. + + Pack_Id := + Make_Defining_Identifier (Loc, + Chars => New_External_Name + (Related_Id => Chars (Def_Ent), + Suffix => "GP", + Suffix_Index => Source_Offset (Sloc (Def_Ent)))); + end if; + + Pack_Decl := Make_Package_Declaration (Loc, + Specification => Make_Package_Specification (Loc, + Defining_Unit_Name => Pack_Id, + Visible_Declarations => Renaming_List, + End_Label => Empty)); + + Set_Instance_Spec (N, Pack_Decl); + Set_Is_Generic_Instance (Pack_Id); + + -- Case of not a compilation unit + + if Nkind (Parent (N)) /= N_Compilation_Unit then + Mark_Rewrite_Insertion (Pack_Decl); + Insert_Before (N, Pack_Decl); + Set_Has_Completion (Pack_Id); + + -- Case of an instantiation that is a compilation unit + + -- Place declaration on current node so context is complete + -- for analysis (including nested instantiations), and for + -- use in a context_clause (see Analyze_With_Clause). + + else + Set_Unit (Parent (N), Pack_Decl); + Set_Parent_Spec (Pack_Decl, Parent_Spec (N)); + end if; + + Analyze (Pack_Decl); + Check_Formal_Packages (Pack_Id); + Set_Is_Generic_Instance (Pack_Id, False); + + -- Body of the enclosing package is supplied when instantiating + -- the subprogram body, after semantic analysis is completed. + + if Nkind (Parent (N)) = N_Compilation_Unit then + + -- Remove package itself from visibility, so it does not + -- conflict with subprogram. + + Set_Name_Entity_Id (Chars (Pack_Id), Homonym (Pack_Id)); + + -- Set name and scope of internal subprogram so that the + -- proper external name will be generated. The proper scope + -- is the scope of the wrapper package. + + Set_Chars (Anon_Id, Chars (Defining_Entity (N))); + Set_Scope (Anon_Id, Scope (Pack_Id)); + end if; + + Set_Is_Generic_Instance (Anon_Id); + Act_Decl_Id := New_Copy (Anon_Id); + + Set_Parent (Act_Decl_Id, Parent (Anon_Id)); + Set_Chars (Act_Decl_Id, Chars (Defining_Entity (N))); + Set_Sloc (Act_Decl_Id, Sloc (Defining_Entity (N))); + Set_Comes_From_Source (Act_Decl_Id, True); + + -- The signature may involve types that are not frozen yet, but + -- the subprogram will be frozen at the point the wrapper package + -- is frozen, so it does not need its own freeze node. In fact, if + -- one is created, it might conflict with the freezing actions from + -- the wrapper package (see 7206-013). + + Set_Has_Delayed_Freeze (Anon_Id, False); + + -- If the instance is a child unit, mark the Id accordingly. Mark + -- the anonymous entity as well, which is the real subprogram and + -- which is used when the instance appears in a context clause. + + Set_Is_Child_Unit (Act_Decl_Id, Is_Child_Unit (Defining_Entity (N))); + Set_Is_Child_Unit (Anon_Id, Is_Child_Unit (Defining_Entity (N))); + New_Overloaded_Entity (Act_Decl_Id); + Check_Eliminated (Act_Decl_Id); + + -- In compilation unit case, kill elaboration checks on the + -- instantiation, since they are never needed -- the body is + -- instantiated at the same point as the spec. + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Suppress_Elaboration_Warnings (Act_Decl_Id); + Set_Suppress_Elaboration_Checks (Act_Decl_Id); + Set_Is_Compilation_Unit (Anon_Id); + + Set_Cunit_Entity (Current_Sem_Unit, Pack_Id); + end if; + + -- The instance is not a freezing point for the new subprogram. + + Set_Is_Frozen (Act_Decl_Id, False); + + if Nkind (Defining_Entity (N)) = N_Defining_Operator_Symbol then + Valid_Operator_Definition (Act_Decl_Id); + end if; + + Set_Alias (Act_Decl_Id, Anon_Id); + Set_Parent (Act_Decl_Id, Parent (Anon_Id)); + Set_Has_Completion (Act_Decl_Id); + Set_Related_Instance (Pack_Id, Act_Decl_Id); + + if Nkind (Parent (N)) = N_Compilation_Unit then + Set_Body_Required (Parent (N), False); + end if; + + end Analyze_Instance_And_Renamings; + + -- Start of processing for Analyze_Subprogram_Instantiation + + begin + -- Very first thing: apply the special kludge for Text_IO processing + -- in case we are instantiating one of the children of [Wide_]Text_IO. + -- Of course such an instantiation is bogus (these are packages, not + -- subprograms), but we get a better error message if we do this. + + Text_IO_Kludge (Gen_Id); + + -- Make node global for error reporting. + + Instantiation_Node := N; + Pre_Analyze_Actuals (N); + + Check_Generic_Child_Unit (Gen_Id, Parent_Installed); + Gen_Unit := Entity (Gen_Id); + + Generate_Reference (Gen_Unit, Gen_Id); + + if Nkind (Gen_Id) = N_Identifier + and then Chars (Gen_Unit) = Chars (Defining_Entity (N)) + then + Error_Msg_NE + ("& is hidden within declaration of instance", Gen_Id, Gen_Unit); + end if; + + if Etype (Gen_Unit) = Any_Type then return; end if; + + -- Verify that it is a generic subprogram of the right kind, and that + -- it does not lead to a circular instantiation. + + if Ekind (Gen_Unit) /= E_Generic_Procedure + and then Ekind (Gen_Unit) /= E_Generic_Function + then + Error_Msg_N ("expect generic subprogram in instantiation", Gen_Id); + + elsif In_Open_Scopes (Gen_Unit) then + Error_Msg_NE ("instantiation of & within itself", N, Gen_Unit); + + elsif Contains_Instance_Of (Gen_Unit, Current_Scope, Gen_Id) then + Error_Msg_Node_2 := Current_Scope; + Error_Msg_NE + ("circular Instantiation: & instantiated in &!", N, Gen_Unit); + Circularity_Detected := True; + + elsif K = E_Procedure + and then Ekind (Gen_Unit) /= E_Generic_Procedure + then + if Ekind (Gen_Unit) = E_Generic_Function then + Error_Msg_N + ("cannot instantiate generic function as procedure", Gen_Id); + else + Error_Msg_N + ("expect name of generic procedure in instantiation", Gen_Id); + end if; + + elsif K = E_Function + and then Ekind (Gen_Unit) /= E_Generic_Function + then + if Ekind (Gen_Unit) = E_Generic_Procedure then + Error_Msg_N + ("cannot instantiate generic procedure as function", Gen_Id); + else + Error_Msg_N + ("expect name of generic function in instantiation", Gen_Id); + end if; + + else + -- If renaming, indicate that this is instantiation of renamed unit + + if Present (Renamed_Object (Gen_Unit)) + and then (Ekind (Renamed_Object (Gen_Unit)) = E_Generic_Procedure + or else + Ekind (Renamed_Object (Gen_Unit)) = E_Generic_Function) + then + Gen_Unit := Renamed_Object (Gen_Unit); + Set_Entity (Gen_Id, Gen_Unit); + end if; + + if In_Extended_Main_Source_Unit (N) then + Set_Is_Instantiated (Gen_Unit); + Generate_Reference (Gen_Unit, N); + end if; + + Gen_Decl := Unit_Declaration_Node (Gen_Unit); + Spec := Specification (Gen_Decl); + + -- The subprogram itself cannot contain a nested instance, so + -- the current parent is left empty. + + Save_Env (Gen_Unit, Empty); + + -- Initialize renamings map, for error checking. + + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + + Create_Instantiation_Source (N, Gen_Unit, S_Adjustment); + + -- Copy original generic tree, to produce text for instantiation. + + Act_Tree := + Copy_Generic_Node + (Original_Node (Gen_Decl), Empty, Instantiating => True); + + Act_Spec := Specification (Act_Tree); + Renaming_List := + Analyze_Associations + (N, + Generic_Formal_Declarations (Act_Tree), + Generic_Formal_Declarations (Gen_Decl)); + + -- Build the subprogram declaration, which does not appear + -- in the generic template, and give it a sloc consistent + -- with that of the template. + + Set_Defining_Unit_Name (Act_Spec, Anon_Id); + Set_Generic_Parent (Act_Spec, Gen_Unit); + Act_Decl := + Make_Subprogram_Declaration (Sloc (Act_Spec), + Specification => Act_Spec); + + Set_Categorization_From_Pragmas (Act_Decl); + + if Parent_Installed then + Hide_Current_Scope; + end if; + + Append (Act_Decl, Renaming_List); + Analyze_Instance_And_Renamings; + + -- If the generic is marked Import (Intrinsic), then so is the + -- instance. This indicates that there is no body to instantiate. + -- If generic is marked inline, so it the instance, and the + -- anonymous subprogram it renames. If inlined, or else if inlining + -- is enabled for the compilation, we generate the instance body + -- even if it is not within the main unit. + + -- Any other pragmas might also be inherited ??? + + if Is_Intrinsic_Subprogram (Gen_Unit) then + Set_Is_Intrinsic_Subprogram (Anon_Id); + Set_Is_Intrinsic_Subprogram (Act_Decl_Id); + + if Chars (Gen_Unit) = Name_Unchecked_Conversion then + Validate_Unchecked_Conversion (N, Act_Decl_Id); + end if; + end if; + + Generate_Definition (Act_Decl_Id); + + Set_Is_Inlined (Act_Decl_Id, Is_Inlined (Gen_Unit)); + Set_Is_Inlined (Anon_Id, Is_Inlined (Gen_Unit)); + + Check_Elab_Instantiation (N); + Check_Hidden_Child_Unit (N, Gen_Unit, Act_Decl_Id); + + -- Subject to change, pending on if other pragmas are inherited ??? + + Validate_Categorization_Dependency (N, Act_Decl_Id); + + if not Is_Intrinsic_Subprogram (Act_Decl_Id) then + + if not Generic_Separately_Compiled (Gen_Unit) then + Inherit_Context (Gen_Decl, N); + end if; + + Restore_Private_Views (Pack_Id, False); + + -- If the context requires a full instantiation, mark node for + -- subsequent construction of the body. + + if (Is_In_Main_Unit (N) + or else Is_Inlined (Act_Decl_Id)) + and then (Operating_Mode = Generate_Code + or else (Operating_Mode = Check_Semantics + and then Tree_Output)) + and then (Expander_Active or else Tree_Output) + and then not ABE_Is_Certain (N) + and then not Is_Eliminated (Act_Decl_Id) + then + Pending_Instantiations.Increment_Last; + Pending_Instantiations.Table (Pending_Instantiations.Last) := + (N, Act_Decl, Expander_Active, Current_Sem_Unit); + Check_Forward_Instantiation (N, Gen_Decl); + + -- The wrapper package is always delayed, because it does + -- not constitute a freeze point, but to insure that the + -- freeze node is placed properly, it is created directly + -- when instantiating the body (otherwise the freeze node + -- might appear to early for nested instantiations). + + elsif Nkind (Parent (N)) = N_Compilation_Unit then + + -- For ASIS purposes, indicate that the wrapper package has + -- replaced the instantiation node. + + Rewrite (N, Unit (Parent (N))); + Set_Unit (Parent (N), N); + end if; + + elsif Nkind (Parent (N)) = N_Compilation_Unit then + + -- Replace instance node for library-level instantiations + -- of intrinsic subprograms, for ASIS use. + + Rewrite (N, Unit (Parent (N))); + Set_Unit (Parent (N), N); + end if; + + if Parent_Installed then + Remove_Parent; + end if; + + Restore_Env; + Generic_Renamings.Set_Last (0); + Generic_Renamings_HTable.Reset; + end if; + + exception + when Instantiation_Error => + if Parent_Installed then + Remove_Parent; + end if; + + end Analyze_Subprogram_Instantiation; + + --------------------- + -- Associated_Node -- + --------------------- + + function Associated_Node (N : Node_Id) return Node_Id is + Assoc : Node_Id := Node4 (N); + -- ??? what is Node4 being used for here? + + begin + if Nkind (Assoc) /= Nkind (N) then + return Assoc; + + elsif Nkind (Assoc) = N_Aggregate + or else Nkind (Assoc) = N_Extension_Aggregate + then + return Assoc; + else + -- If the node is part of an inner generic, it may itself have been + -- remapped into a further generic copy. Node4 is otherwise used for + -- the entity of the node, and will be of a different node kind, or + -- else N has been rewritten as a literal or function call. + + while Present (Node4 (Assoc)) + and then Nkind (Node4 (Assoc)) = Nkind (Assoc) + loop + Assoc := Node4 (Assoc); + end loop; + + -- Follow and additional link in case the final node was rewritten. + -- This can only happen with nested generic units. + + if (Nkind (Assoc) = N_Identifier or else Nkind (Assoc) in N_Op) + and then Present (Node4 (Assoc)) + and then (Nkind (Node4 (Assoc)) = N_Function_Call + or else Nkind (Node4 (Assoc)) = N_Explicit_Dereference + or else Nkind (Node4 (Assoc)) = N_Integer_Literal + or else Nkind (Node4 (Assoc)) = N_Real_Literal + or else Nkind (Node4 (Assoc)) = N_String_Literal) + then + Assoc := Node4 (Assoc); + end if; + + return Assoc; + end if; + end Associated_Node; + + ------------------------------------------- + -- Build_Instance_Compilation_Unit_Nodes -- + ------------------------------------------- + + procedure Build_Instance_Compilation_Unit_Nodes + (N : Node_Id; + Act_Body : Node_Id; + Act_Decl : Node_Id) + is + Decl_Cunit : Node_Id; + Body_Cunit : Node_Id; + Citem : Node_Id; + New_Main : constant Entity_Id := Defining_Entity (Act_Decl); + Old_Main : constant Entity_Id := Cunit_Entity (Main_Unit); + + begin + -- A new compilation unit node is built for the instance declaration + + Decl_Cunit := + Make_Compilation_Unit (Sloc (N), + Context_Items => Empty_List, + Unit => Act_Decl, + Aux_Decls_Node => + Make_Compilation_Unit_Aux (Sloc (N))); + + Set_Parent_Spec (Act_Decl, Parent_Spec (N)); + Set_Body_Required (Decl_Cunit, True); + + -- We use the original instantiation compilation unit as the resulting + -- compilation unit of the instance, since this is the main unit. + + Rewrite (N, Act_Body); + Body_Cunit := Parent (N); + + -- The two compilation unit nodes are linked by the Library_Unit field + + Set_Library_Unit (Decl_Cunit, Body_Cunit); + Set_Library_Unit (Body_Cunit, Decl_Cunit); + + -- The context clause items on the instantiation, which are now + -- attached to the body compilation unit (since the body overwrote + -- the original instantiation node), semantically belong on the spec, + -- so copy them there. It's harmless to leave them on the body as well. + -- In fact one could argue that they belong in both places. + + Citem := First (Context_Items (Body_Cunit)); + while Present (Citem) loop + Append (New_Copy (Citem), Context_Items (Decl_Cunit)); + Next (Citem); + end loop; + + -- Propagate categorization flags on packages, so that they appear + -- in ali file for the spec of the unit. + + if Ekind (New_Main) = E_Package then + Set_Is_Pure (Old_Main, Is_Pure (New_Main)); + Set_Is_Preelaborated (Old_Main, Is_Preelaborated (New_Main)); + Set_Is_Remote_Types (Old_Main, Is_Remote_Types (New_Main)); + Set_Is_Shared_Passive (Old_Main, Is_Shared_Passive (New_Main)); + Set_Is_Remote_Call_Interface + (Old_Main, Is_Remote_Call_Interface (New_Main)); + end if; + + -- Make entry in Units table, so that binder can generate call to + -- elaboration procedure for body, if any. + + Make_Instance_Unit (Body_Cunit); + Main_Unit_Entity := New_Main; + Set_Cunit_Entity (Main_Unit, Main_Unit_Entity); + + -- Build elaboration entity, since the instance may certainly + -- generate elaboration code requiring a flag for protection. + + Build_Elaboration_Entity (Decl_Cunit, New_Main); + end Build_Instance_Compilation_Unit_Nodes; + + ----------------------------------- + -- Check_Formal_Package_Instance -- + ----------------------------------- + + -- If the formal has specific parameters, they must match those of the + -- actual. Both of them are instances, and the renaming declarations + -- for their formal parameters appear in the same order in both. The + -- analyzed formal has been analyzed in the context of the current + -- instance. + + procedure Check_Formal_Package_Instance + (Formal_Pack : Entity_Id; + Actual_Pack : Entity_Id) + is + E1 : Entity_Id := First_Entity (Actual_Pack); + E2 : Entity_Id := First_Entity (Formal_Pack); + + Expr1 : Node_Id; + Expr2 : Node_Id; + + procedure Check_Mismatch (B : Boolean); + -- Common error routine for mismatch between the parameters of + -- the actual instance and those of the formal package. + + procedure Check_Mismatch (B : Boolean) is + begin + if B then + Error_Msg_NE + ("actual for & in actual instance does not match formal", + Parent (Actual_Pack), E1); + end if; + end Check_Mismatch; + + -- Start of processing for Check_Formal_Package_Instance + + begin + while Present (E1) + and then Present (E2) + loop + exit when Ekind (E1) = E_Package + and then Renamed_Entity (E1) = Renamed_Entity (Actual_Pack); + + if Is_Type (E1) then + + -- Subtypes must statically match. E1 and E2 are the + -- local entities that are subtypes of the actuals. + -- Itypes generated for other parameters need not be checked, + -- the check will be performed on the parameters themselves. + + if not Is_Itype (E1) + and then not Is_Itype (E2) + then + Check_Mismatch + (not Is_Type (E2) + or else Etype (E1) /= Etype (E2) + or else not Subtypes_Statically_Match (E1, E2)); + end if; + + elsif Ekind (E1) = E_Constant then + + -- IN parameters must denote the same static value, or + -- the same constant, or the literal null. + + Expr1 := Expression (Parent (E1)); + + if Ekind (E2) /= E_Constant then + Check_Mismatch (True); + goto Next_E; + else + Expr2 := Expression (Parent (E2)); + end if; + + if Is_Static_Expression (Expr1) then + + if not Is_Static_Expression (Expr2) then + Check_Mismatch (True); + + elsif Is_Integer_Type (Etype (E1)) then + + declare + V1 : Uint := Expr_Value (Expr1); + V2 : Uint := Expr_Value (Expr2); + begin + Check_Mismatch (V1 /= V2); + end; + + elsif Is_Real_Type (Etype (E1)) then + + declare + V1 : Ureal := Expr_Value_R (Expr1); + V2 : Ureal := Expr_Value_R (Expr2); + begin + Check_Mismatch (V1 /= V2); + end; + + elsif Is_String_Type (Etype (E1)) + and then Nkind (Expr1) = N_String_Literal + then + + if Nkind (Expr2) /= N_String_Literal then + Check_Mismatch (True); + else + Check_Mismatch + (not String_Equal (Strval (Expr1), Strval (Expr2))); + end if; + end if; + + elsif Is_Entity_Name (Expr1) then + if Is_Entity_Name (Expr2) then + if Entity (Expr1) = Entity (Expr2) then + null; + + elsif Ekind (Entity (Expr2)) = E_Constant + and then Is_Entity_Name (Constant_Value (Entity (Expr2))) + and then + Entity (Constant_Value (Entity (Expr2))) = Entity (Expr1) + then + null; + else + Check_Mismatch (True); + end if; + else + Check_Mismatch (True); + end if; + + elsif Nkind (Expr1) = N_Null then + Check_Mismatch (Nkind (Expr1) /= N_Null); + + else + Check_Mismatch (True); + end if; + + elsif Ekind (E1) = E_Variable + or else Ekind (E1) = E_Package + then + Check_Mismatch + (Ekind (E1) /= Ekind (E2) + or else Renamed_Object (E1) /= Renamed_Object (E2)); + + elsif Is_Overloadable (E1) then + + -- Verify that the names of the entities match. + -- What if actual is an attribute ??? + + Check_Mismatch + (Ekind (E2) /= Ekind (E1) or else (Alias (E1)) /= Alias (E2)); + + else + raise Program_Error; + end if; + + <<Next_E>> + Next_Entity (E1); + Next_Entity (E2); + end loop; + end Check_Formal_Package_Instance; + + --------------------------- + -- Check_Formal_Packages -- + --------------------------- + + procedure Check_Formal_Packages (P_Id : Entity_Id) is + E : Entity_Id; + Formal_P : Entity_Id; + + begin + -- Iterate through the declarations in the instance, looking for + -- package renaming declarations that denote instances of formal + -- packages. Stop when we find the renaming of the current package + -- itself. The declaration for a formal package without a box is + -- followed by an internal entity that repeats the instantiation. + + E := First_Entity (P_Id); + while Present (E) loop + if Ekind (E) = E_Package then + if Renamed_Object (E) = P_Id then + exit; + + elsif Nkind (Parent (E)) /= N_Package_Renaming_Declaration then + null; + + elsif not Box_Present (Parent (Associated_Formal_Package (E))) then + Formal_P := Next_Entity (E); + Check_Formal_Package_Instance (Formal_P, E); + end if; + end if; + + Next_Entity (E); + end loop; + end Check_Formal_Packages; + + --------------------------------- + -- Check_Forward_Instantiation -- + --------------------------------- + + procedure Check_Forward_Instantiation (N : Node_Id; Decl : Node_Id) is + S : Entity_Id; + Gen_Comp : Entity_Id := Cunit_Entity (Get_Source_Unit (Decl)); + + begin + -- The instantiation appears before the generic body if we are in the + -- scope of the unit containing the generic, either in its spec or in + -- the package body. and before the generic body. + + if Ekind (Gen_Comp) = E_Package_Body then + Gen_Comp := Spec_Entity (Gen_Comp); + end if; + + if In_Open_Scopes (Gen_Comp) + and then No (Corresponding_Body (Decl)) + then + S := Current_Scope; + + while Present (S) + and then not Is_Compilation_Unit (S) + and then not Is_Child_Unit (S) + loop + if Ekind (S) = E_Package then + Set_Has_Forward_Instantiation (S); + end if; + + S := Scope (S); + end loop; + end if; + end Check_Forward_Instantiation; + + --------------------------- + -- Check_Generic_Actuals -- + --------------------------- + + -- The visibility of the actuals may be different between the + -- point of generic instantiation and the instantiation of the body. + + procedure Check_Generic_Actuals + (Instance : Entity_Id; + Is_Formal_Box : Boolean) + is + E : Entity_Id; + Astype : Entity_Id; + + begin + E := First_Entity (Instance); + while Present (E) loop + if Is_Type (E) + and then Nkind (Parent (E)) = N_Subtype_Declaration + and then Scope (Etype (E)) /= Instance + and then Is_Entity_Name (Subtype_Indication (Parent (E))) + then + Check_Private_View (Subtype_Indication (Parent (E))); + Set_Is_Generic_Actual_Type (E, True); + Set_Is_Hidden (E, False); + + -- We constructed the generic actual type as a subtype of + -- the supplied type. This means that it normally would not + -- inherit subtype specific attributes of the actual, which + -- is wrong for the generic case. + + Astype := Ancestor_Subtype (E); + + if No (Astype) then + + -- can happen when E is an itype that is the full view of + -- a private type completed, e.g. with a constrained array. + + Astype := Base_Type (E); + end if; + + Set_Size_Info (E, (Astype)); + Set_RM_Size (E, RM_Size (Astype)); + Set_First_Rep_Item (E, First_Rep_Item (Astype)); + + if Is_Discrete_Or_Fixed_Point_Type (E) then + Set_RM_Size (E, RM_Size (Astype)); + + -- In nested instances, the base type of an access actual + -- may itself be private, and need to be exchanged. + + elsif Is_Access_Type (E) + and then Is_Private_Type (Etype (E)) + then + Check_Private_View + (New_Occurrence_Of (Etype (E), Sloc (Instance))); + end if; + + elsif Ekind (E) = E_Package then + + -- If this is the renaming for the current instance, we're done. + -- Otherwise it is a formal package. If the corresponding formal + -- was declared with a box, the (instantiations of the) generic + -- formal part are also visible. Otherwise, ignore the entity + -- created to validate the actuals. + + if Renamed_Object (E) = Instance then + exit; + + elsif Nkind (Parent (E)) /= N_Package_Renaming_Declaration then + null; + + -- The visibility of a formal of an enclosing generic is already + -- correct. + + elsif Denotes_Formal_Package (E) then + null; + + elsif Present (Associated_Formal_Package (E)) + and then Box_Present (Parent (Associated_Formal_Package (E))) + then + Check_Generic_Actuals (Renamed_Object (E), True); + Set_Is_Hidden (E, False); + end if; + + else + Set_Is_Hidden (E, not Is_Formal_Box); + end if; + + Next_Entity (E); + end loop; + + end Check_Generic_Actuals; + + ------------------------------ + -- Check_Generic_Child_Unit -- + ------------------------------ + + procedure Check_Generic_Child_Unit + (Gen_Id : Node_Id; + Parent_Installed : in out Boolean) + is + Loc : constant Source_Ptr := Sloc (Gen_Id); + Gen_Par : Entity_Id := Empty; + Inst_Par : Entity_Id; + E : Entity_Id; + S : Node_Id; + + function Find_Generic_Child + (Scop : Entity_Id; + Id : Node_Id) + return Entity_Id; + -- Search generic parent for possible child unit. + + function In_Enclosing_Instance return Boolean; + -- Within an instance of the parent, the child unit may be denoted + -- by a simple name. Examine enclosing scopes to locate a possible + -- parent instantiation. + + function Find_Generic_Child + (Scop : Entity_Id; + Id : Node_Id) + return Entity_Id + is + E : Entity_Id; + + begin + -- If entity of name is already set, instance has already been + -- resolved, e.g. in an enclosing instantiation. + + if Present (Entity (Id)) then + if Scope (Entity (Id)) = Scop then + return Entity (Id); + else + return Empty; + end if; + + else + E := First_Entity (Scop); + while Present (E) loop + if Chars (E) = Chars (Id) + and then Is_Child_Unit (E) + then + if Is_Child_Unit (E) + and then not Is_Visible_Child_Unit (E) + then + Error_Msg_NE + ("generic child unit& is not visible", Gen_Id, E); + end if; + + Set_Entity (Id, E); + return E; + end if; + + Next_Entity (E); + end loop; + + return Empty; + end if; + end Find_Generic_Child; + + function In_Enclosing_Instance return Boolean is + Enclosing_Instance : Node_Id; + + begin + Enclosing_Instance := Current_Scope; + + while Present (Enclosing_Instance) loop + exit when Ekind (Enclosing_Instance) = E_Package + and then Nkind (Parent (Enclosing_Instance)) = + N_Package_Specification + and then Present + (Generic_Parent (Parent (Enclosing_Instance))); + + Enclosing_Instance := Scope (Enclosing_Instance); + end loop; + + if Present (Enclosing_Instance) then + E := Find_Generic_Child + (Generic_Parent (Parent (Enclosing_Instance)), Gen_Id); + else + return False; + end if; + + if Present (E) then + Rewrite (Gen_Id, + Make_Expanded_Name (Loc, + Chars => Chars (E), + Prefix => New_Occurrence_Of (Enclosing_Instance, Loc), + Selector_Name => New_Occurrence_Of (E, Loc))); + + Set_Entity (Gen_Id, E); + Set_Etype (Gen_Id, Etype (E)); + Parent_Installed := False; -- Already in scope. + return True; + else + Analyze (Gen_Id); + return False; + end if; + end In_Enclosing_Instance; + + -- Start of processing for Check_Generic_Child_Unit + + begin + -- If the name of the generic is given by a selected component, it + -- may be the name of a generic child unit, and the prefix is the name + -- of an instance of the parent, in which case the child unit must be + -- visible. If this instance is not in scope, it must be placed there + -- and removed after instantiation, because what is being instantiated + -- is not the original child, but the corresponding child present in + -- the instance of the parent. + + -- If the child is instantiated within the parent, it can be given by + -- a simple name. In this case the instance is already in scope, but + -- the child generic must be recovered from the generic parent as well. + + if Nkind (Gen_Id) = N_Selected_Component then + S := Selector_Name (Gen_Id); + Analyze (Prefix (Gen_Id)); + Inst_Par := Entity (Prefix (Gen_Id)); + + if Ekind (Inst_Par) = E_Package + and then Present (Renamed_Object (Inst_Par)) + then + Inst_Par := Renamed_Object (Inst_Par); + end if; + + if Ekind (Inst_Par) = E_Package then + if Nkind (Parent (Inst_Par)) = N_Package_Specification then + Gen_Par := Generic_Parent (Parent (Inst_Par)); + + elsif Nkind (Parent (Inst_Par)) = N_Defining_Program_Unit_Name + and then + Nkind (Parent (Parent (Inst_Par))) = N_Package_Specification + then + Gen_Par := Generic_Parent (Parent (Parent (Inst_Par))); + end if; + + elsif Ekind (Inst_Par) = E_Generic_Package + and then Nkind (Parent (Gen_Id)) = N_Formal_Package_Declaration + then + + -- A formal package may be a real child package, and not the + -- implicit instance within a parent. In this case the child is + -- not visible and has to be retrieved explicitly as well. + + Gen_Par := Inst_Par; + end if; + + if Present (Gen_Par) then + + -- The prefix denotes an instantiation. The entity itself + -- may be a nested generic, or a child unit. + + E := Find_Generic_Child (Gen_Par, S); + + if Present (E) then + Change_Selected_Component_To_Expanded_Name (Gen_Id); + Set_Entity (Gen_Id, E); + Set_Etype (Gen_Id, Etype (E)); + Set_Entity (S, E); + Set_Etype (S, Etype (E)); + + -- Indicate that this is a reference to the parent. + + if In_Extended_Main_Source_Unit (Gen_Id) then + Set_Is_Instantiated (Inst_Par); + end if; + + -- A common mistake is to replicate the naming scheme of + -- a hierarchy by instantiating a generic child directly, + -- rather than the implicit child in a parent instance: + -- + -- generic .. package Gpar is .. + -- generic .. package Gpar.Child is .. + -- package Par is new Gpar (); + + -- with Gpar.Child; + -- package Par.Child is new Gpar.Child (); + -- rather than Par.Child + -- + -- In this case the instantiation is within Par, which is + -- an instance, but Gpar does not denote Par because we are + -- not IN the instance of Gpar, so this is illegal. The test + -- below recognizes this particular case. + + if Is_Child_Unit (E) + and then not Comes_From_Source (Entity (Prefix (Gen_Id))) + and then (not In_Instance + or else Nkind (Parent (Parent (Gen_Id))) = + N_Compilation_Unit) + then + Error_Msg_N + ("prefix of generic child unit must be instance of parent", + Gen_Id); + end if; + + if not In_Open_Scopes (Inst_Par) + and then Nkind (Parent (Gen_Id)) + not in N_Generic_Renaming_Declaration + then + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + + else + -- If the generic parent does not contain an entity that + -- corresponds to the selector, the instance doesn't either. + -- Analyzing the node will yield the appropriate error message. + -- If the entity is not a child unit, then it is an inner + -- generic in the parent. + + Analyze (Gen_Id); + end if; + + else + Analyze (Gen_Id); + + if Is_Child_Unit (Entity (Gen_Id)) + and then Nkind (Parent (Gen_Id)) + not in N_Generic_Renaming_Declaration + and then not In_Open_Scopes (Inst_Par) + then + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + end if; + + elsif Nkind (Gen_Id) = N_Expanded_Name then + + -- Entity already present, analyze prefix, whose meaning may be + -- an instance in the current context. If it is an instance of + -- a relative within another, the proper parent may still have + -- to be installed, if they are not of the same generation. + + Analyze (Prefix (Gen_Id)); + Inst_Par := Entity (Prefix (Gen_Id)); + + if In_Enclosing_Instance then + null; + + elsif Present (Entity (Gen_Id)) + and then Is_Child_Unit (Entity (Gen_Id)) + and then not In_Open_Scopes (Inst_Par) + then + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + + elsif In_Enclosing_Instance then + -- The child unit is found in some enclosing scope. + null; + + else + Analyze (Gen_Id); + + -- If this is the renaming of the implicit child in a parent + -- instance, recover the parent name and install it. + + if Is_Entity_Name (Gen_Id) then + E := Entity (Gen_Id); + + if Is_Generic_Unit (E) + and then Nkind (Parent (E)) in N_Generic_Renaming_Declaration + and then Is_Child_Unit (Renamed_Object (E)) + and then Is_Generic_Unit (Scope (Renamed_Object (E))) + and then Nkind (Name (Parent (E))) = N_Expanded_Name + then + Rewrite (Gen_Id, + New_Copy_Tree (Name (Parent (E)))); + Inst_Par := Entity (Prefix (Gen_Id)); + + if not In_Open_Scopes (Inst_Par) then + Install_Parent (Inst_Par); + Parent_Installed := True; + end if; + + -- If it is a child unit of a non-generic parent, it may be + -- use-visible and given by a direct name. Install parent as + -- for other cases. + + elsif Is_Generic_Unit (E) + and then Is_Child_Unit (E) + and then + Nkind (Parent (Gen_Id)) not in N_Generic_Renaming_Declaration + and then not Is_Generic_Unit (Scope (E)) + then + if not In_Open_Scopes (Scope (E)) then + Install_Parent (Scope (E)); + Parent_Installed := True; + end if; + end if; + end if; + end if; + end Check_Generic_Child_Unit; + + ----------------------------- + -- Check_Hidden_Child_Unit -- + ----------------------------- + + procedure Check_Hidden_Child_Unit + (N : Node_Id; + Gen_Unit : Entity_Id; + Act_Decl_Id : Entity_Id) + is + Gen_Id : Node_Id := Name (N); + + begin + if Is_Child_Unit (Gen_Unit) + and then Is_Child_Unit (Act_Decl_Id) + and then Nkind (Gen_Id) = N_Expanded_Name + and then Entity (Prefix (Gen_Id)) = Scope (Act_Decl_Id) + and then Chars (Gen_Unit) = Chars (Act_Decl_Id) + then + Error_Msg_Node_2 := Scope (Act_Decl_Id); + Error_Msg_NE + ("generic unit & is implicitly declared in &", + Defining_Unit_Name (N), Gen_Unit); + Error_Msg_N ("\instance must have different name", + Defining_Unit_Name (N)); + end if; + end Check_Hidden_Child_Unit; + + ------------------------ + -- Check_Private_View -- + ------------------------ + + procedure Check_Private_View (N : Node_Id) is + T : constant Entity_Id := Etype (N); + BT : Entity_Id; + + begin + -- Exchange views if the type was not private in the generic but is + -- private at the point of instantiation. Do not exchange views if + -- the scope of the type is in scope. This can happen if both generic + -- and instance are sibling units, or if type is defined in a parent. + -- In this case the visibility of the type will be correct for all + -- semantic checks. + + if Present (T) then + BT := Base_Type (T); + + if Is_Private_Type (T) + and then not Has_Private_View (N) + and then Present (Full_View (T)) + and then not In_Open_Scopes (Scope (T)) + then + -- In the generic, the full type was visible. Save the + -- private entity, for subsequent exchange. + + Switch_View (T); + + elsif Has_Private_View (N) + and then not Is_Private_Type (T) + and then not Has_Been_Exchanged (T) + and then Etype (Associated_Node (N)) /= T + then + -- Only the private declaration was visible in the generic. If + -- the type appears in a subtype declaration, the subtype in the + -- instance must have a view compatible with that of its parent, + -- which must be exchanged (see corresponding code in Restore_ + -- Private_Views). Otherwise, if the type is defined in a parent + -- unit, leave full visibility within instance, which is safe. + + if In_Open_Scopes (Scope (Base_Type (T))) + and then not Is_Private_Type (Base_Type (T)) + and then Comes_From_Source (Base_Type (T)) + then + null; + + elsif Nkind (Parent (N)) = N_Subtype_Declaration + or else not In_Private_Part (Scope (Base_Type (T))) + then + Append_Elmt (T, Exchanged_Views); + Exchange_Declarations (Etype (Associated_Node (N))); + end if; + + -- For composite types with inconsistent representation + -- exchange component types accordingly. + + elsif Is_Access_Type (T) + and then Is_Private_Type (Designated_Type (T)) + and then Present (Full_View (Designated_Type (T))) + then + Switch_View (Designated_Type (T)); + + elsif Is_Array_Type (T) + and then Is_Private_Type (Component_Type (T)) + and then not Has_Private_View (N) + and then Present (Full_View (Component_Type (T))) + then + Switch_View (Component_Type (T)); + + elsif Is_Private_Type (T) + and then Present (Full_View (T)) + and then Is_Array_Type (Full_View (T)) + and then Is_Private_Type (Component_Type (Full_View (T))) + then + Switch_View (T); + + -- Finally, a non-private subtype may have a private base type, + -- which must be exchanged for consistency. This can happen when + -- instantiating a package body, when the scope stack is empty but + -- in fact the subtype and the base type are declared in an enclosing + -- scope. + + elsif not Is_Private_Type (T) + and then not Has_Private_View (N) + and then Is_Private_Type (Base_Type (T)) + and then Present (Full_View (BT)) + and then not Is_Generic_Type (BT) + and then not In_Open_Scopes (BT) + then + Append_Elmt (Full_View (BT), Exchanged_Views); + Exchange_Declarations (BT); + end if; + end if; + end Check_Private_View; + + -------------------------- + -- Contains_Instance_Of -- + -------------------------- + + function Contains_Instance_Of + (Inner : Entity_Id; + Outer : Entity_Id; + N : Node_Id) + return Boolean + is + Elmt : Elmt_Id; + Scop : Entity_Id; + + begin + Scop := Outer; + + -- Verify that there are no circular instantiations. We check whether + -- the unit contains an instance of the current scope or some enclosing + -- scope (in case one of the instances appears in a subunit). Longer + -- circularities involving subunits might seem too pathological to + -- consider, but they were not too pathological for the authors of + -- DEC bc30vsq, so we loop over all enclosing scopes, and mark all + -- enclosing generic scopes as containing an instance. + + loop + -- Within a generic subprogram body, the scope is not generic, to + -- allow for recursive subprograms. Use the declaration to determine + -- whether this is a generic unit. + + if Ekind (Scop) = E_Generic_Package + or else (Is_Subprogram (Scop) + and then Nkind (Unit_Declaration_Node (Scop)) = + N_Generic_Subprogram_Declaration) + then + Elmt := First_Elmt (Inner_Instances (Inner)); + + while Present (Elmt) loop + if Node (Elmt) = Scop then + Error_Msg_Node_2 := Inner; + Error_Msg_NE + ("circular Instantiation: & instantiated within &!", + N, Scop); + return True; + + elsif Node (Elmt) = Inner then + return True; + + elsif Contains_Instance_Of (Node (Elmt), Scop, N) then + Error_Msg_Node_2 := Inner; + Error_Msg_NE + ("circular Instantiation: & instantiated within &!", + N, Node (Elmt)); + return True; + end if; + + Next_Elmt (Elmt); + end loop; + + -- Indicate that Inner is being instantiated within Scop. + + Append_Elmt (Inner, Inner_Instances (Scop)); + end if; + + if Scop = Standard_Standard then + exit; + else + Scop := Scope (Scop); + end if; + end loop; + + return False; + end Contains_Instance_Of; + + ----------------------- + -- Copy_Generic_Node -- + ----------------------- + + function Copy_Generic_Node + (N : Node_Id; + Parent_Id : Node_Id; + Instantiating : Boolean) + return Node_Id + is + Ent : Entity_Id; + New_N : Node_Id; + + function Copy_Generic_Descendant (D : Union_Id) return Union_Id; + -- Check the given value of one of the Fields referenced by the + -- current node to determine whether to copy it recursively. The + -- field may hold a Node_Id, a List_Id, or an Elist_Id, or a plain + -- value (Sloc, Uint, Char) in which case it need not be copied. + + function Copy_Generic_Elist (E : Elist_Id) return Elist_Id; + -- Make copy of element list. + + function Copy_Generic_List + (L : List_Id; + Parent_Id : Node_Id) + return List_Id; + -- Apply Copy_Node recursively to the members of a node list. + + ----------------------------- + -- Copy_Generic_Descendant -- + ----------------------------- + + function Copy_Generic_Descendant (D : Union_Id) return Union_Id is + begin + if D = Union_Id (Empty) then + return D; + + elsif D in Node_Range then + return Union_Id + (Copy_Generic_Node (Node_Id (D), New_N, Instantiating)); + + elsif D in List_Range then + return Union_Id (Copy_Generic_List (List_Id (D), New_N)); + + elsif D in Elist_Range then + return Union_Id (Copy_Generic_Elist (Elist_Id (D))); + + -- Nothing else is copyable (e.g. Uint values), return as is + + else + return D; + end if; + end Copy_Generic_Descendant; + + ------------------------ + -- Copy_Generic_Elist -- + ------------------------ + + function Copy_Generic_Elist (E : Elist_Id) return Elist_Id is + M : Elmt_Id; + L : Elist_Id; + + begin + if Present (E) then + L := New_Elmt_List; + M := First_Elmt (E); + while Present (M) loop + Append_Elmt + (Copy_Generic_Node (Node (M), Empty, Instantiating), L); + Next_Elmt (M); + end loop; + + return L; + + else + return No_Elist; + end if; + end Copy_Generic_Elist; + + ----------------------- + -- Copy_Generic_List -- + ----------------------- + + function Copy_Generic_List + (L : List_Id; + Parent_Id : Node_Id) + return List_Id + is + N : Node_Id; + New_L : List_Id; + + begin + if Present (L) then + New_L := New_List; + Set_Parent (New_L, Parent_Id); + + N := First (L); + while Present (N) loop + Append (Copy_Generic_Node (N, Empty, Instantiating), New_L); + Next (N); + end loop; + + return New_L; + + else + return No_List; + end if; + end Copy_Generic_List; + + -- Start of processing for Copy_Generic_Node + + begin + if N = Empty then + return N; + end if; + + New_N := New_Copy (N); + + if Instantiating then + Adjust_Instantiation_Sloc (New_N, S_Adjustment); + end if; + + if not Is_List_Member (N) then + Set_Parent (New_N, Parent_Id); + end if; + + -- If defining identifier, then all fields have been copied already + + if Nkind (New_N) in N_Entity then + null; + + -- Special casing for identifiers and other entity names and operators + + elsif (Nkind (New_N) = N_Identifier + or else Nkind (New_N) = N_Character_Literal + or else Nkind (New_N) = N_Expanded_Name + or else Nkind (New_N) = N_Operator_Symbol + or else Nkind (New_N) in N_Op) + then + if not Instantiating then + + -- Link both nodes in order to assign subsequently the + -- entity of the copy to the original node, in case this + -- is a global reference. + + Set_Associated_Node (N, New_N); + + -- If we are within an instantiation, this is a nested generic + -- that has already been analyzed at the point of definition. We + -- must preserve references that were global to the enclosing + -- parent at that point. Other occurrences, whether global or + -- local to the current generic, must be resolved anew, so we + -- reset the entity in the generic copy. A global reference has + -- a smaller depth than the parent, or else the same depth in + -- case both are distinct compilation units. + + -- It is also possible for Current_Instantiated_Parent to be + -- defined, and for this not to be a nested generic, namely + -- if the unit is loaded through Rtsfind. In that case, the + -- entity of New_N is only a link to the associated node, and + -- not a defining occurrence. + + -- The entities for parent units in the defining_program_unit + -- of a generic child unit are established when the context of + -- the unit is first analyzed, before the generic copy is made. + -- They are preserved in the copy for use in ASIS queries. + + Ent := Entity (New_N); + + if No (Current_Instantiated_Parent.Gen_Id) then + if No (Ent) + or else Nkind (Ent) /= N_Defining_Identifier + or else Nkind (Parent (N)) /= N_Defining_Program_Unit_Name + then + Set_Associated_Node (New_N, Empty); + end if; + + elsif No (Ent) + or else + not (Nkind (Ent) = N_Defining_Identifier + or else + Nkind (Ent) = N_Defining_Character_Literal + or else + Nkind (Ent) = N_Defining_Operator_Symbol) + or else No (Scope (Ent)) + or else Scope (Ent) = Current_Instantiated_Parent.Gen_Id + or else (Scope_Depth (Scope (Ent)) > + Scope_Depth (Current_Instantiated_Parent.Gen_Id) + and then + Get_Source_Unit (Ent) = + Get_Source_Unit (Current_Instantiated_Parent.Gen_Id)) + then + Set_Associated_Node (New_N, Empty); + end if; + + -- Case of instantiating identifier or some other name or operator + + else + -- If the associated node is still defined, the entity in + -- it is global, and must be copied to the instance. + + if Present (Associated_Node (N)) then + if Nkind (Associated_Node (N)) = Nkind (N) then + Set_Entity (New_N, Entity (Associated_Node (N))); + Check_Private_View (N); + + elsif Nkind (Associated_Node (N)) = N_Function_Call then + Set_Entity (New_N, Entity (Name (Associated_Node (N)))); + + else + Set_Entity (New_N, Empty); + end if; + end if; + end if; + + -- For expanded name, we must copy the Prefix and Selector_Name + + if Nkind (N) = N_Expanded_Name then + + Set_Prefix + (New_N, Copy_Generic_Node (Prefix (N), New_N, Instantiating)); + + Set_Selector_Name (New_N, + Copy_Generic_Node (Selector_Name (N), New_N, Instantiating)); + + -- For operators, we must copy the right operand + + elsif Nkind (N) in N_Op then + + Set_Right_Opnd (New_N, + Copy_Generic_Node (Right_Opnd (N), New_N, Instantiating)); + + -- And for binary operators, the left operand as well + + if Nkind (N) in N_Binary_Op then + Set_Left_Opnd (New_N, + Copy_Generic_Node (Left_Opnd (N), New_N, Instantiating)); + end if; + end if; + + -- Special casing for stubs + + elsif Nkind (N) in N_Body_Stub then + + -- In any case, we must copy the specification or defining + -- identifier as appropriate. + + if Nkind (N) = N_Subprogram_Body_Stub then + Set_Specification (New_N, + Copy_Generic_Node (Specification (N), New_N, Instantiating)); + + else + Set_Defining_Identifier (New_N, + Copy_Generic_Node + (Defining_Identifier (N), New_N, Instantiating)); + end if; + + -- If we are not instantiating, then this is where we load and + -- analyze subunits, i.e. at the point where the stub occurs. A + -- more permissivle system might defer this analysis to the point + -- of instantiation, but this seems to complicated for now. + + if not Instantiating then + declare + Subunit_Name : constant Unit_Name_Type := Get_Unit_Name (N); + Subunit : Node_Id; + Unum : Unit_Number_Type; + New_Body : Node_Id; + + begin + Unum := + Load_Unit + (Load_Name => Subunit_Name, + Required => False, + Subunit => True, + Error_Node => N); + + -- If the proper body is not found, a warning message will + -- be emitted when analyzing the stub, or later at the the + -- point of instantiation. Here we just leave the stub as is. + + if Unum = No_Unit then + Subunits_Missing := True; + goto Subunit_Not_Found; + end if; + + Subunit := Cunit (Unum); + + -- We must create a generic copy of the subunit, in order + -- to perform semantic analysis on it, and we must replace + -- the stub in the original generic unit with the subunit, + -- in order to preserve non-local references within. + + -- Only the proper body needs to be copied. Library_Unit and + -- context clause are simply inherited by the generic copy. + -- Note that the copy (which may be recursive if there are + -- nested subunits) must be done first, before attaching it + -- to the enclosing generic. + + New_Body := + Copy_Generic_Node + (Proper_Body (Unit (Subunit)), + Empty, Instantiating => False); + + -- Now place the original proper body in the original + -- generic unit. + + Rewrite (N, Proper_Body (Unit (Subunit))); + Set_Was_Originally_Stub (N); + + -- Finally replace the body of the subunit with its copy, + -- and make this new subunit into the library unit of the + -- generic copy, which does not have stubs any longer. + + Set_Proper_Body (Unit (Subunit), New_Body); + Set_Library_Unit (New_N, Subunit); + Inherit_Context (Unit (Subunit), N); + + end; + + -- If we are instantiating, this must be an error case, since + -- otherwise we would have replaced the stub node by the proper + -- body that corresponds. So just ignore it in the copy (i.e. + -- we have copied it, and that is good enough). + + else + null; + end if; + + <<Subunit_Not_Found>> null; + + -- If the node is a compilation unit, it is the subunit of a stub, + -- which has been loaded already (see code below). In this case, + -- the library unit field of N points to the parent unit (which + -- is a compilation unit) and need not (and cannot!) be copied. + + -- When the proper body of the stub is analyzed, thie library_unit + -- link is used to establish the proper context (see sem_ch10). + + -- The other fields of a compilation unit are copied as usual + + elsif Nkind (N) = N_Compilation_Unit then + + -- This code can only be executed when not instantiating, because + -- in the copy made for an instantiation, the compilation unit + -- node has disappeared at the point that a stub is replaced by + -- its proper body. + + pragma Assert (not Instantiating); + + Set_Context_Items (New_N, + Copy_Generic_List (Context_Items (N), New_N)); + + Set_Unit (New_N, + Copy_Generic_Node (Unit (N), New_N, False)); + + Set_First_Inlined_Subprogram (New_N, + Copy_Generic_Node + (First_Inlined_Subprogram (N), New_N, False)); + + Set_Aux_Decls_Node (New_N, + Copy_Generic_Node (Aux_Decls_Node (N), New_N, False)); + + -- For an assignment node, the assignment is known to be semantically + -- legal if we are instantiating the template. This avoids incorrect + -- diagnostics in generated code. + + elsif Nkind (N) = N_Assignment_Statement then + + -- Copy name and expression fields in usual manner + + Set_Name (New_N, + Copy_Generic_Node (Name (N), New_N, Instantiating)); + + Set_Expression (New_N, + Copy_Generic_Node (Expression (N), New_N, Instantiating)); + + if Instantiating then + Set_Assignment_OK (Name (New_N), True); + end if; + + elsif Nkind (N) = N_Aggregate + or else Nkind (N) = N_Extension_Aggregate + then + + if not Instantiating then + Set_Associated_Node (N, New_N); + + else + if Present (Associated_Node (N)) + and then Nkind (Associated_Node (N)) = Nkind (N) + then + -- In the generic the aggregate has some composite type. + -- If at the point of instantiation the type has a private + -- view, install the full view (and that of its ancestors, + -- if any). + + declare + T : Entity_Id := (Etype (Associated_Node (New_N))); + Rt : Entity_Id; + + begin + if Present (T) + and then Is_Private_Type (T) + then + Switch_View (T); + end if; + + if Present (T) + and then Is_Tagged_Type (T) + and then Is_Derived_Type (T) + then + Rt := Root_Type (T); + + loop + T := Etype (T); + + if Is_Private_Type (T) then + Switch_View (T); + end if; + + exit when T = Rt; + end loop; + end if; + end; + end if; + end if; + + Set_Field1 (New_N, Copy_Generic_Descendant (Field1 (N))); + Set_Field2 (New_N, Copy_Generic_Descendant (Field2 (N))); + Set_Field3 (New_N, Copy_Generic_Descendant (Field3 (N))); + Set_Field5 (New_N, Copy_Generic_Descendant (Field5 (N))); + + -- For a proper body, we must catch the case of a proper body that + -- replaces a stub. This represents the point at which a separate + -- compilation unit, and hence template file, may be referenced, so + -- we must make a new source instantiation entry for the template + -- of the subunit, and ensure that all nodes in the subunit are + -- adjusted using this new source instantiation entry. + + elsif Nkind (N) in N_Proper_Body then + + declare + Save_Adjustment : constant Sloc_Adjustment := S_Adjustment; + + begin + if Instantiating and then Was_Originally_Stub (N) then + Create_Instantiation_Source + (Instantiation_Node, Defining_Entity (N), S_Adjustment); + end if; + + -- Now copy the fields of the proper body, using the new + -- adjustment factor if one was needed as per test above. + + Set_Field1 (New_N, Copy_Generic_Descendant (Field1 (N))); + Set_Field2 (New_N, Copy_Generic_Descendant (Field2 (N))); + Set_Field3 (New_N, Copy_Generic_Descendant (Field3 (N))); + Set_Field4 (New_N, Copy_Generic_Descendant (Field4 (N))); + Set_Field5 (New_N, Copy_Generic_Descendant (Field5 (N))); + + -- Restore the original adjustment factor in case changed + + S_Adjustment := Save_Adjustment; + end; + + -- Don't copy Ident or Comment pragmas, since the comment belongs + -- to the generic unit, not to the instantiating unit. + + elsif Nkind (N) = N_Pragma + and then Instantiating + then + declare + Prag_Id : constant Pragma_Id := Get_Pragma_Id (Chars (N)); + + begin + if Prag_Id = Pragma_Ident + or else Prag_Id = Pragma_Comment + then + New_N := Make_Null_Statement (Sloc (N)); + + else + Set_Field1 (New_N, Copy_Generic_Descendant (Field1 (N))); + Set_Field2 (New_N, Copy_Generic_Descendant (Field2 (N))); + Set_Field3 (New_N, Copy_Generic_Descendant (Field3 (N))); + Set_Field4 (New_N, Copy_Generic_Descendant (Field4 (N))); + Set_Field5 (New_N, Copy_Generic_Descendant (Field5 (N))); + end if; + end; + + -- For the remaining nodes, copy recursively their descendants. + + else + Set_Field1 (New_N, Copy_Generic_Descendant (Field1 (N))); + Set_Field2 (New_N, Copy_Generic_Descendant (Field2 (N))); + Set_Field3 (New_N, Copy_Generic_Descendant (Field3 (N))); + Set_Field4 (New_N, Copy_Generic_Descendant (Field4 (N))); + Set_Field5 (New_N, Copy_Generic_Descendant (Field5 (N))); + + if Instantiating + and then Nkind (N) = N_Subprogram_Body + then + Set_Generic_Parent (Specification (New_N), N); + end if; + end if; + + return New_N; + end Copy_Generic_Node; + + ---------------------------- + -- Denotes_Formal_Package -- + ---------------------------- + + function Denotes_Formal_Package (Pack : Entity_Id) return Boolean is + Par : constant Entity_Id := Current_Instantiated_Parent.Act_Id; + Scop : Entity_Id := Scope (Pack); + E : Entity_Id; + + begin + if Ekind (Scop) = E_Generic_Package + or else Nkind (Unit_Declaration_Node (Scop)) + = N_Generic_Subprogram_Declaration + then + return True; + + elsif Nkind (Parent (Pack)) = N_Formal_Package_Declaration then + return True; + + elsif No (Par) then + return False; + + else + -- Check whether this package is associated with a formal + -- package of the enclosing instantiation. Iterate over the + -- list of renamings. + + E := First_Entity (Par); + while Present (E) loop + + if Ekind (E) /= E_Package + or else Nkind (Parent (E)) /= N_Package_Renaming_Declaration + then + null; + elsif Renamed_Object (E) = Par then + return False; + + elsif Renamed_Object (E) = Pack then + return True; + end if; + + Next_Entity (E); + end loop; + + return False; + end if; + end Denotes_Formal_Package; + + ----------------- + -- End_Generic -- + ----------------- + + procedure End_Generic is + begin + -- ??? More things could be factored out in this + -- routine. Should probably be done at a later stage. + + Inside_A_Generic := Generic_Flags.Table (Generic_Flags.Last); + Generic_Flags.Decrement_Last; + + Expander_Mode_Restore; + end End_Generic; + + ---------------------- + -- Find_Actual_Type -- + ---------------------- + + function Find_Actual_Type + (Typ : Entity_Id; + Gen_Scope : Entity_Id) + return Entity_Id + is + T : Entity_Id; + + begin + if not Is_Child_Unit (Gen_Scope) then + return Get_Instance_Of (Typ); + + elsif not Is_Generic_Type (Typ) + or else Scope (Typ) = Gen_Scope + then + return Get_Instance_Of (Typ); + + else + T := Current_Entity (Typ); + while Present (T) loop + if In_Open_Scopes (Scope (T)) then + return T; + end if; + + T := Homonym (T); + end loop; + + return Typ; + end if; + end Find_Actual_Type; + + ---------------------------- + -- Freeze_Subprogram_Body -- + ---------------------------- + + procedure Freeze_Subprogram_Body + (Inst_Node : Node_Id; + Gen_Body : Node_Id; + Pack_Id : Entity_Id) + is + F_Node : Node_Id; + Gen_Unit : constant Entity_Id := Entity (Name (Inst_Node)); + Par : constant Entity_Id := Scope (Gen_Unit); + Enc_G : Entity_Id; + Enc_I : Node_Id; + E_G_Id : Entity_Id; + + function Earlier (N1, N2 : Node_Id) return Boolean; + -- Yields True if N1 and N2 appear in the same compilation unit, + -- ignoring subunits, and if N1 is to the left of N2 in a left-to-right + -- traversal of the tree for the unit. + + function Enclosing_Body (N : Node_Id) return Node_Id; + -- Find innermost package body that encloses the given node, and which + -- is not a compilation unit. Freeze nodes for the instance, or for its + -- enclosing body, may be inserted after the enclosing_body of the + -- generic unit. + + function Package_Freeze_Node (B : Node_Id) return Node_Id; + -- Find entity for given package body, and locate or create a freeze + -- node for it. + + function True_Parent (N : Node_Id) return Node_Id; + -- For a subunit, return parent of corresponding stub. + + ------------- + -- Earlier -- + ------------- + + function Earlier (N1, N2 : Node_Id) return Boolean is + D1 : Integer := 0; + D2 : Integer := 0; + P1 : Node_Id := N1; + P2 : Node_Id := N2; + + procedure Find_Depth (P : in out Node_Id; D : in out Integer); + -- Find distance from given node to enclosing compilation unit. + + procedure Find_Depth (P : in out Node_Id; D : in out Integer) is + begin + while Present (P) + and then Nkind (P) /= N_Compilation_Unit + loop + P := True_Parent (P); + D := D + 1; + end loop; + end Find_Depth; + + begin + Find_Depth (P1, D1); + Find_Depth (P2, D2); + + if P1 /= P2 then + return False; + else + P1 := N1; + P2 := N2; + end if; + + while D1 > D2 loop + P1 := True_Parent (P1); + D1 := D1 - 1; + end loop; + + while D2 > D1 loop + P2 := True_Parent (P2); + D2 := D2 - 1; + end loop; + + -- At this point P1 and P2 are at the same distance from the root. + -- We examine their parents until we find a common declarative + -- list, at which point we can establish their relative placement + -- by comparing their ultimate slocs. If we reach the root, + -- N1 and N2 do not descend from the same declarative list (e.g. + -- one is nested in the declarative part and the other is in a block + -- in the statement part) and the earlier one is already frozen. + + while not Is_List_Member (P1) + or else not Is_List_Member (P2) + or else List_Containing (P1) /= List_Containing (P2) + loop + P1 := True_Parent (P1); + P2 := True_Parent (P2); + + if Nkind (Parent (P1)) = N_Subunit then + P1 := Corresponding_Stub (Parent (P1)); + end if; + + if Nkind (Parent (P2)) = N_Subunit then + P2 := Corresponding_Stub (Parent (P2)); + end if; + + if P1 = P2 then + return False; + end if; + end loop; + + return + Top_Level_Location (Sloc (P1)) < Top_Level_Location (Sloc (P2)); + end Earlier; + + -------------------- + -- Enclosing_Body -- + -------------------- + + function Enclosing_Body (N : Node_Id) return Node_Id is + P : Node_Id := Parent (N); + + begin + while Present (P) + and then Nkind (Parent (P)) /= N_Compilation_Unit + loop + if Nkind (P) = N_Package_Body then + + if Nkind (Parent (P)) = N_Subunit then + return Corresponding_Stub (Parent (P)); + else + return P; + end if; + end if; + + P := True_Parent (P); + end loop; + + return Empty; + end Enclosing_Body; + + ------------------------- + -- Package_Freeze_Node -- + ------------------------- + + function Package_Freeze_Node (B : Node_Id) return Node_Id is + Id : Entity_Id; + + begin + if Nkind (B) = N_Package_Body then + Id := Corresponding_Spec (B); + + else pragma Assert (Nkind (B) = N_Package_Body_Stub); + Id := Corresponding_Spec (Proper_Body (Unit (Library_Unit (B)))); + end if; + + Ensure_Freeze_Node (Id); + return Freeze_Node (Id); + end Package_Freeze_Node; + + ----------------- + -- True_Parent -- + ----------------- + + function True_Parent (N : Node_Id) return Node_Id is + begin + if Nkind (Parent (N)) = N_Subunit then + return Parent (Corresponding_Stub (Parent (N))); + else + return Parent (N); + end if; + end True_Parent; + + -- Start of processing of Freeze_Subprogram_Body + + begin + -- If the instance and the generic body appear within the same + -- unit, and the instance preceeds the generic, the freeze node for + -- the instance must appear after that of the generic. If the generic + -- is nested within another instance I2, then current instance must + -- be frozen after I2. In both cases, the freeze nodes are those of + -- enclosing packages. Otherwise, the freeze node is placed at the end + -- of the current declarative part. + + Enc_G := Enclosing_Body (Gen_Body); + Enc_I := Enclosing_Body (Inst_Node); + Ensure_Freeze_Node (Pack_Id); + F_Node := Freeze_Node (Pack_Id); + + if Is_Generic_Instance (Par) + and then Present (Freeze_Node (Par)) + and then + In_Same_Declarative_Part (Freeze_Node (Par), Inst_Node) + then + Insert_After (Freeze_Node (Par), F_Node); + + -- The body enclosing the instance should be frozen after the body + -- that includes the generic, because the body of the instance may + -- make references to entities therein. If the two are not in the + -- same declarative part, or if the one enclosing the instance is + -- frozen already, freeze the instance at the end of the current + -- declarative part. + + elsif Is_Generic_Instance (Par) + and then Present (Freeze_Node (Par)) + and then Present (Enc_I) + then + if In_Same_Declarative_Part (Freeze_Node (Par), Enc_I) + or else + (Nkind (Enc_I) = N_Package_Body + and then + In_Same_Declarative_Part (Freeze_Node (Par), Parent (Enc_I))) + then + + -- The enclosing package may contain several instances. Rather + -- than computing the earliest point at which to insert its + -- freeze node, we place it at the end of the declarative part + -- of the parent of the generic. + + Insert_After_Last_Decl + (Freeze_Node (Par), Package_Freeze_Node (Enc_I)); + end if; + + Insert_After_Last_Decl (Inst_Node, F_Node); + + elsif Present (Enc_G) + and then Present (Enc_I) + and then Enc_G /= Enc_I + and then Earlier (Inst_Node, Gen_Body) + then + if Nkind (Enc_G) = N_Package_Body then + E_G_Id := Corresponding_Spec (Enc_G); + else pragma Assert (Nkind (Enc_G) = N_Package_Body_Stub); + E_G_Id := + Corresponding_Spec (Proper_Body (Unit (Library_Unit (Enc_G)))); + end if; + + -- Freeze package that encloses instance, and place node after + -- package that encloses generic. If enclosing package is already + -- frozen we have to assume it is at the proper place. This may + -- be a potential ABE that requires dynamic checking. + + Insert_After_Last_Decl (Enc_G, Package_Freeze_Node (Enc_I)); + + -- Freeze enclosing subunit before instance + + Ensure_Freeze_Node (E_G_Id); + + if not Is_List_Member (Freeze_Node (E_G_Id)) then + Insert_After (Enc_G, Freeze_Node (E_G_Id)); + end if; + + Insert_After_Last_Decl (Inst_Node, F_Node); + + else + + -- If none of the above, insert freeze node at the end of the + -- current declarative part. + + Insert_After_Last_Decl (Inst_Node, F_Node); + end if; + end Freeze_Subprogram_Body; + + ---------------- + -- Get_Gen_Id -- + ---------------- + + function Get_Gen_Id (E : Assoc_Ptr) return Entity_Id is + begin + return Generic_Renamings.Table (E).Gen_Id; + end Get_Gen_Id; + + --------------------- + -- Get_Instance_Of -- + --------------------- + + function Get_Instance_Of (A : Entity_Id) return Entity_Id is + Res : Assoc_Ptr := Generic_Renamings_HTable.Get (A); + begin + if Res /= Assoc_Null then + return Generic_Renamings.Table (Res).Act_Id; + else + -- On exit, entity is not instantiated: not a generic parameter, + -- or else parameter of an inner generic unit. + + return A; + end if; + end Get_Instance_Of; + + ------------------------------------ + -- Get_Package_Instantiation_Node -- + ------------------------------------ + + function Get_Package_Instantiation_Node (A : Entity_Id) return Node_Id is + Decl : Node_Id := Unit_Declaration_Node (A); + Inst : Node_Id; + + begin + -- If the instantiation is a compilation unit that does not need a + -- body then the instantiation node has been rewritten as a package + -- declaration for the instance, and we return the original node. + -- If it is a compilation unit and the instance node has not been + -- rewritten, then it is still the unit of the compilation. + -- Otherwise the instantiation node appears after the declaration. + -- If the entity is a formal package, the declaration may have been + -- rewritten as a generic declaration (in the case of a formal with a + -- box) or left as a formal package declaration if it has actuals, and + -- is found with a forward search. + + if Nkind (Parent (Decl)) = N_Compilation_Unit then + if Nkind (Original_Node (Decl)) = N_Package_Instantiation then + return Original_Node (Decl); + else + return Unit (Parent (Decl)); + end if; + + elsif Nkind (Decl) = N_Generic_Package_Declaration + and then Nkind (Original_Node (Decl)) = N_Formal_Package_Declaration + then + return Original_Node (Decl); + + else + Inst := Next (Decl); + while Nkind (Inst) /= N_Package_Instantiation + and then Nkind (Inst) /= N_Formal_Package_Declaration + loop + Next (Inst); + end loop; + + return Inst; + end if; + end Get_Package_Instantiation_Node; + + ------------------------ + -- Has_Been_Exchanged -- + ------------------------ + + function Has_Been_Exchanged (E : Entity_Id) return Boolean is + Next : Elmt_Id := First_Elmt (Exchanged_Views); + + begin + while Present (Next) loop + if Full_View (Node (Next)) = E then + return True; + end if; + + Next_Elmt (Next); + end loop; + + return False; + end Has_Been_Exchanged; + + ---------- + -- Hash -- + ---------- + + function Hash (F : Entity_Id) return HTable_Range is + begin + return HTable_Range (F mod HTable_Size); + end Hash; + + ------------------------ + -- Hide_Current_Scope -- + ------------------------ + + procedure Hide_Current_Scope is + C : constant Entity_Id := Current_Scope; + E : Entity_Id; + + begin + Set_Is_Hidden_Open_Scope (C); + E := First_Entity (C); + + while Present (E) loop + if Is_Immediately_Visible (E) then + Set_Is_Immediately_Visible (E, False); + Append_Elmt (E, Hidden_Entities); + end if; + + Next_Entity (E); + end loop; + + -- Make the scope name invisible as well. This is necessary, but + -- might conflict with calls to Rtsfind later on, in case the scope + -- is a predefined one. There is no clean solution to this problem, so + -- for now we depend on the user not redefining Standard itself in one + -- of the parent units. + + if Is_Immediately_Visible (C) + and then C /= Standard_Standard + then + Set_Is_Immediately_Visible (C, False); + Append_Elmt (C, Hidden_Entities); + end if; + + end Hide_Current_Scope; + + ------------------------------ + -- In_Same_Declarative_Part -- + ------------------------------ + + function In_Same_Declarative_Part + (F_Node : Node_Id; + Inst : Node_Id) + return Boolean + is + Decls : Node_Id := Parent (F_Node); + Nod : Node_Id := Parent (Inst); + + begin + while Present (Nod) loop + if Nod = Decls then + return True; + + elsif Nkind (Nod) = N_Subprogram_Body + or else Nkind (Nod) = N_Package_Body + or else Nkind (Nod) = N_Task_Body + or else Nkind (Nod) = N_Protected_Body + or else Nkind (Nod) = N_Block_Statement + then + return False; + + elsif Nkind (Nod) = N_Subunit then + Nod := Corresponding_Stub (Nod); + + elsif Nkind (Nod) = N_Compilation_Unit then + return False; + else + Nod := Parent (Nod); + end if; + end loop; + + return False; + end In_Same_Declarative_Part; + + --------------------- + -- Inherit_Context -- + --------------------- + + procedure Inherit_Context (Gen_Decl : Node_Id; Inst : Node_Id) is + Current_Context : List_Id; + Current_Unit : Node_Id; + Item : Node_Id; + New_I : Node_Id; + + begin + if Nkind (Parent (Gen_Decl)) = N_Compilation_Unit then + + -- The inherited context is attached to the enclosing compilation + -- unit. This is either the main unit, or the declaration for the + -- main unit (in case the instantation appears within the package + -- declaration and the main unit is its body). + + Current_Unit := Parent (Inst); + while Present (Current_Unit) + and then Nkind (Current_Unit) /= N_Compilation_Unit + loop + Current_Unit := Parent (Current_Unit); + end loop; + + Current_Context := Context_Items (Current_Unit); + + Item := First (Context_Items (Parent (Gen_Decl))); + while Present (Item) loop + if Nkind (Item) = N_With_Clause then + New_I := New_Copy (Item); + Set_Implicit_With (New_I, True); + Append (New_I, Current_Context); + end if; + + Next (Item); + end loop; + end if; + end Inherit_Context; + + ---------------------------- + -- Insert_After_Last_Decl -- + ---------------------------- + + procedure Insert_After_Last_Decl (N : Node_Id; F_Node : Node_Id) is + L : List_Id := List_Containing (N); + P : Node_Id := Parent (L); + + begin + if not Is_List_Member (F_Node) then + if Nkind (P) = N_Package_Specification + and then L = Visible_Declarations (P) + and then Present (Private_Declarations (P)) + and then not Is_Empty_List (Private_Declarations (P)) + then + L := Private_Declarations (P); + end if; + + Insert_After (Last (L), F_Node); + end if; + end Insert_After_Last_Decl; + + ------------------ + -- Install_Body -- + ------------------ + + procedure Install_Body + (Act_Body : Node_Id; + N : Node_Id; + Gen_Body : Node_Id; + Gen_Decl : Node_Id) + is + Act_Id : Entity_Id := Corresponding_Spec (Act_Body); + Act_Unit : constant Node_Id := + Unit (Cunit (Get_Source_Unit (N))); + F_Node : Node_Id; + Gen_Id : Entity_Id := Corresponding_Spec (Gen_Body); + Gen_Unit : constant Node_Id := + Unit (Cunit (Get_Source_Unit (Gen_Decl))); + Orig_Body : Node_Id := Gen_Body; + Par : constant Entity_Id := Scope (Gen_Id); + Body_Unit : Node_Id; + + Must_Delay : Boolean; + + function Enclosing_Subp (Id : Entity_Id) return Entity_Id; + -- Find subprogram (if any) that encloses instance and/or generic body. + + function True_Sloc (N : Node_Id) return Source_Ptr; + -- If the instance is nested inside a generic unit, the Sloc of the + -- instance indicates the place of the original definition, not the + -- point of the current enclosing instance. Pending a better usage of + -- Slocs to indicate instantiation places, we determine the place of + -- origin of a node by finding the maximum sloc of any ancestor node. + -- Why is this not equivalent fo Top_Level_Location ??? + + function Enclosing_Subp (Id : Entity_Id) return Entity_Id is + Scop : Entity_Id := Scope (Id); + + begin + while Scop /= Standard_Standard + and then not Is_Overloadable (Scop) + loop + Scop := Scope (Scop); + end loop; + + return Scop; + end Enclosing_Subp; + + function True_Sloc (N : Node_Id) return Source_Ptr is + Res : Source_Ptr; + N1 : Node_Id; + + begin + Res := Sloc (N); + N1 := N; + while Present (N1) and then N1 /= Act_Unit loop + if Sloc (N1) > Res then + Res := Sloc (N1); + end if; + + N1 := Parent (N1); + end loop; + + return Res; + end True_Sloc; + + -- Start of processing for Install_Body + + begin + -- If the body is a subunit, the freeze point is the corresponding + -- stub in the current compilation, not the subunit itself. + + if Nkind (Parent (Gen_Body)) = N_Subunit then + Orig_Body := Corresponding_Stub (Parent (Gen_Body)); + else + Orig_Body := Gen_Body; + end if; + + Body_Unit := Unit (Cunit (Get_Source_Unit (Orig_Body))); + + -- If the instantiation and the generic definition appear in the + -- same package declaration, this is an early instantiation. + -- If they appear in the same declarative part, it is an early + -- instantiation only if the generic body appears textually later, + -- and the generic body is also in the main unit. + + -- If instance is nested within a subprogram, and the generic body is + -- not, the instance is delayed because the enclosing body is. If + -- instance and body are within the same scope, or the same sub- + -- program body, indicate explicitly that the instance is delayed. + + Must_Delay := + (Gen_Unit = Act_Unit + and then ((Nkind (Gen_Unit) = N_Package_Declaration) + or else Nkind (Gen_Unit) = N_Generic_Package_Declaration + or else (Gen_Unit = Body_Unit + and then True_Sloc (N) < Sloc (Orig_Body))) + and then Is_In_Main_Unit (Gen_Unit) + and then (Scope (Act_Id) = Scope (Gen_Id) + or else + Enclosing_Subp (Act_Id) = Enclosing_Subp (Gen_Id))); + + -- If this is an early instantiation, the freeze node is placed after + -- the generic body. Otherwise, if the generic appears in an instance, + -- we cannot freeze the current instance until the outer one is frozen. + -- This is only relevant if the current instance is nested within some + -- inner scope not itself within the outer instance. If this scope is + -- a package body in the same declarative part as the outer instance, + -- then that body needs to be frozen after the outer instance. Finally, + -- if no delay is needed, we place the freeze node at the end of the + -- current declarative part. + + if Expander_Active then + Ensure_Freeze_Node (Act_Id); + F_Node := Freeze_Node (Act_Id); + + if Must_Delay then + Insert_After (Orig_Body, F_Node); + + elsif Is_Generic_Instance (Par) + and then Present (Freeze_Node (Par)) + and then Scope (Act_Id) /= Par + then + -- Freeze instance of inner generic after instance of enclosing + -- generic. + + if In_Same_Declarative_Part (Freeze_Node (Par), N) then + Insert_After (Freeze_Node (Par), F_Node); + + -- Freeze package enclosing instance of inner generic after + -- instance of enclosing generic. + + elsif Nkind (Parent (N)) = N_Package_Body + and then In_Same_Declarative_Part (Freeze_Node (Par), Parent (N)) + then + + declare + Enclosing : Entity_Id := Corresponding_Spec (Parent (N)); + + begin + Insert_After_Last_Decl (N, F_Node); + Ensure_Freeze_Node (Enclosing); + + if not Is_List_Member (Freeze_Node (Enclosing)) then + Insert_After (Freeze_Node (Par), Freeze_Node (Enclosing)); + end if; + end; + + else + Insert_After_Last_Decl (N, F_Node); + end if; + + else + Insert_After_Last_Decl (N, F_Node); + end if; + end if; + + Set_Is_Frozen (Act_Id); + Insert_Before (N, Act_Body); + Mark_Rewrite_Insertion (Act_Body); + end Install_Body; + + -------------------- + -- Install_Parent -- + -------------------- + + procedure Install_Parent (P : Entity_Id; In_Body : Boolean := False) is + S : Entity_Id := Current_Scope; + Inst_Par : Entity_Id; + First_Par : Entity_Id; + Inst_Node : Node_Id; + Gen_Par : Entity_Id; + First_Gen : Entity_Id; + Ancestors : Elist_Id := New_Elmt_List; + Elmt : Elmt_Id; + + procedure Install_Formal_Packages (Par : Entity_Id); + -- If any of the formals of the parent are formal packages with box, + -- their formal parts are visible in the parent and thus in the child + -- unit as well. Analogous to what is done in Check_Generic_Actuals + -- for the unit itself. + + procedure Install_Noninstance_Specs (Par : Entity_Id); + -- Install the scopes of noninstance parent units ending with Par. + + procedure Install_Spec (Par : Entity_Id); + -- The child unit is within the declarative part of the parent, so + -- the declarations within the parent are immediately visible. + + ----------------------------- + -- Install_Formal_Packages -- + ----------------------------- + + procedure Install_Formal_Packages (Par : Entity_Id) is + E : Entity_Id; + + begin + E := First_Entity (Par); + + while Present (E) loop + + if Ekind (E) = E_Package + and then Nkind (Parent (E)) = N_Package_Renaming_Declaration + then + -- If this is the renaming for the parent instance, done. + + if Renamed_Object (E) = Par then + exit; + + -- The visibility of a formal of an enclosing generic is + -- already correct. + + elsif Denotes_Formal_Package (E) then + null; + + elsif Present (Associated_Formal_Package (E)) + and then Box_Present (Parent (Associated_Formal_Package (E))) + then + Check_Generic_Actuals (Renamed_Object (E), True); + Set_Is_Hidden (E, False); + end if; + end if; + + Next_Entity (E); + end loop; + end Install_Formal_Packages; + + ------------------------------- + -- Install_Noninstance_Specs -- + ------------------------------- + + procedure Install_Noninstance_Specs (Par : Entity_Id) is + begin + if Present (Par) + and then Par /= Standard_Standard + and then not In_Open_Scopes (Par) + then + Install_Noninstance_Specs (Scope (Par)); + Install_Spec (Par); + end if; + end Install_Noninstance_Specs; + + ------------------ + -- Install_Spec -- + ------------------ + + procedure Install_Spec (Par : Entity_Id) is + Spec : constant Node_Id := + Specification (Unit_Declaration_Node (Par)); + + begin + New_Scope (Par); + Set_Is_Immediately_Visible (Par); + Install_Visible_Declarations (Par); + Install_Private_Declarations (Par); + Set_Use (Visible_Declarations (Spec)); + Set_Use (Private_Declarations (Spec)); + end Install_Spec; + + -- Start of processing for Install_Parent + + begin + -- We need to install the parent instance to compile the instantiation + -- of the child, but the child instance must appear in the current + -- scope. Given that we cannot place the parent above the current + -- scope in the scope stack, we duplicate the current scope and unstack + -- both after the instantiation is complete. + + -- If the parent is itself the instantiation of a child unit, we must + -- also stack the instantiation of its parent, and so on. Each such + -- ancestor is the prefix of the name in a prior instantiation. + + -- If this is a nested instance, the parent unit itself resolves to + -- a renaming of the parent instance, whose declaration we need. + + -- Finally, the parent may be a generic (not an instance) when the + -- child unit appears as a formal package. + + Inst_Par := P; + + if Present (Renamed_Entity (Inst_Par)) then + Inst_Par := Renamed_Entity (Inst_Par); + end if; + + First_Par := Inst_Par; + + Gen_Par := + Generic_Parent (Specification (Unit_Declaration_Node (Inst_Par))); + + First_Gen := Gen_Par; + + while Present (Gen_Par) + and then Is_Child_Unit (Gen_Par) + loop + -- Load grandparent instance as well. + + Inst_Node := Get_Package_Instantiation_Node (Inst_Par); + + if Nkind (Name (Inst_Node)) = N_Expanded_Name then + Inst_Par := Entity (Prefix (Name (Inst_Node))); + + if Present (Renamed_Entity (Inst_Par)) then + Inst_Par := Renamed_Entity (Inst_Par); + end if; + + Gen_Par := + Generic_Parent + (Specification (Unit_Declaration_Node (Inst_Par))); + + if Present (Gen_Par) then + Prepend_Elmt (Inst_Par, Ancestors); + + else + -- Parent is not the name of an instantiation. + + Install_Noninstance_Specs (Inst_Par); + + exit; + end if; + + else + -- Previous error. + + exit; + end if; + end loop; + + if Present (First_Gen) then + Append_Elmt (First_Par, Ancestors); + + else + Install_Noninstance_Specs (First_Par); + end if; + + if not Is_Empty_Elmt_List (Ancestors) then + Elmt := First_Elmt (Ancestors); + + while Present (Elmt) loop + Install_Spec (Node (Elmt)); + Install_Formal_Packages (Node (Elmt)); + + Next_Elmt (Elmt); + end loop; + end if; + + if not In_Body then + New_Scope (S); + end if; + end Install_Parent; + + -------------------------------- + -- Instantiate_Formal_Package -- + -------------------------------- + + function Instantiate_Formal_Package + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return List_Id + is + Loc : constant Source_Ptr := Sloc (Actual); + Actual_Pack : Entity_Id; + Formal_Pack : Entity_Id; + Gen_Parent : Entity_Id; + Decls : List_Id; + Nod : Node_Id; + Parent_Spec : Node_Id; + + function Formal_Entity + (F : Node_Id; + Act_Ent : Entity_Id) + return Entity_Id; + -- Returns the entity associated with the given formal F. In the + -- case where F is a formal package, this function will iterate + -- through all of F's formals and enter map associations from the + -- actuals occurring in the formal package's corresponding actual + -- package (obtained via Act_Ent) to the formal package's formal + -- parameters. This function is called recursively for arbitrary + -- levels of formal packages. + + procedure Map_Entities (Form : Entity_Id; Act : Entity_Id); + -- Within the generic part, entities in the formal package are + -- visible. To validate subsequent type declarations, indicate + -- the correspondence betwen the entities in the analyzed formal, + -- and the entities in the actual package. There are three packages + -- involved in the instantiation of a formal package: the parent + -- generic P1 which appears in the generic declaration, the fake + -- instantiation P2 which appears in the analyzed generic, and whose + -- visible entities may be used in subsequent formals, and the actual + -- P3 in the instance. To validate subsequent formals, me indicate + -- that the entities in P2 are mapped into those of P3. The mapping of + -- entities has to be done recursively for nested packages. + + ------------------- + -- Formal_Entity -- + ------------------- + + function Formal_Entity + (F : Node_Id; + Act_Ent : Entity_Id) + return Entity_Id + is + Orig_Node : Node_Id := F; + + begin + case Nkind (F) is + when N_Formal_Object_Declaration => + return Defining_Identifier (F); + + when N_Formal_Type_Declaration => + return Defining_Identifier (F); + + when N_Formal_Subprogram_Declaration => + return Defining_Unit_Name (Specification (F)); + + when N_Formal_Package_Declaration | + N_Generic_Package_Declaration => + + if Nkind (F) = N_Generic_Package_Declaration then + Orig_Node := Original_Node (F); + end if; + + declare + Actual_Ent : Entity_Id := First_Entity (Act_Ent); + Formal_Node : Node_Id; + Formal_Ent : Entity_Id; + + Gen_Decl : Node_Id := + Unit_Declaration_Node + (Entity (Name (Orig_Node))); + Formals : List_Id := + Generic_Formal_Declarations (Gen_Decl); + + begin + if Present (Formals) then + Formal_Node := First_Non_Pragma (Formals); + else + Formal_Node := Empty; + end if; + + -- As for the loop further below, this loop is making + -- a probably invalid assumption about the correspondence + -- between formals and actuals and eventually needs to + -- corrected to account for cases where the formals are + -- not synchronized and in one-to-one correspondence + -- with actuals. ??? + + -- What is certain is that for a legal program the + -- presence of actual entities guarantees the existing + -- of formal ones. + + while Present (Actual_Ent) + and then Present (Formal_Node) + and then Actual_Ent /= First_Private_Entity (Act_Ent) + loop + -- ??? Are the following calls also needed here: + -- + -- Set_Is_Hidden (Actual_Ent, False); + -- Set_Is_Potentially_Use_Visible + -- (Actual_Ent, In_Use (Act_Ent)); + + Formal_Ent := Formal_Entity (Formal_Node, Actual_Ent); + if Present (Formal_Ent) then + Set_Instance_Of (Formal_Ent, Actual_Ent); + end if; + Next_Non_Pragma (Formal_Node); + + Next_Entity (Actual_Ent); + end loop; + end; + + return Defining_Identifier (Orig_Node); + + when N_Use_Package_Clause => + return Empty; + + when N_Use_Type_Clause => + return Empty; + + -- We return Empty for all other encountered forms of + -- declarations because there are some cases of nonformal + -- sorts of declaration that can show up (e.g., when array + -- formals are present). Since it's not clear what kinds + -- can appear among the formals, we won't raise failure here. + + when others => + return Empty; + + end case; + end Formal_Entity; + + ------------------ + -- Map_Entities -- + ------------------ + + procedure Map_Entities (Form : Entity_Id; Act : Entity_Id) is + E1 : Entity_Id; + E2 : Entity_Id; + + begin + Set_Instance_Of (Form, Act); + + E1 := First_Entity (Form); + E2 := First_Entity (Act); + while Present (E1) + and then E1 /= First_Private_Entity (Form) + loop + if not Is_Internal (E1) + and then not Is_Class_Wide_Type (E1) + then + + while Present (E2) + and then Chars (E2) /= Chars (E1) + loop + Next_Entity (E2); + end loop; + + if No (E2) then + exit; + else + Set_Instance_Of (E1, E2); + + if Is_Type (E1) + and then Is_Tagged_Type (E2) + then + Set_Instance_Of + (Class_Wide_Type (E1), Class_Wide_Type (E2)); + end if; + + if Ekind (E1) = E_Package + and then No (Renamed_Object (E1)) + then + Map_Entities (E1, E2); + end if; + end if; + end if; + + Next_Entity (E1); + end loop; + end Map_Entities; + + -- Start of processing for Instantiate_Formal_Package + + begin + Analyze (Actual); + + if not Is_Entity_Name (Actual) + or else Ekind (Entity (Actual)) /= E_Package + then + Error_Msg_N + ("expect package instance to instantiate formal", Actual); + Abandon_Instantiation (Actual); + raise Program_Error; + + else + Actual_Pack := Entity (Actual); + Set_Is_Instantiated (Actual_Pack); + + -- The actual may be a renamed package, or an outer generic + -- formal package whose instantiation is converted into a renaming. + + if Present (Renamed_Object (Actual_Pack)) then + Actual_Pack := Renamed_Object (Actual_Pack); + end if; + + if Nkind (Analyzed_Formal) = N_Formal_Package_Declaration then + Gen_Parent := Get_Instance_Of (Entity (Name (Analyzed_Formal))); + Formal_Pack := Defining_Identifier (Analyzed_Formal); + else + Gen_Parent := + Generic_Parent (Specification (Analyzed_Formal)); + Formal_Pack := + Defining_Unit_Name (Specification (Analyzed_Formal)); + end if; + + if Nkind (Parent (Actual_Pack)) = N_Defining_Program_Unit_Name then + Parent_Spec := Specification (Unit_Declaration_Node (Actual_Pack)); + else + Parent_Spec := Parent (Actual_Pack); + end if; + + if Gen_Parent = Any_Id then + Error_Msg_N + ("previous error in declaration of formal package", Actual); + Abandon_Instantiation (Actual); + + elsif + Generic_Parent (Parent_Spec) /= Get_Instance_Of (Gen_Parent) + then + Error_Msg_NE + ("actual parameter must be instance of&", Actual, Gen_Parent); + Abandon_Instantiation (Actual); + end if; + + Set_Instance_Of (Defining_Identifier (Formal), Actual_Pack); + Map_Entities (Formal_Pack, Actual_Pack); + + Nod := + Make_Package_Renaming_Declaration (Loc, + Defining_Unit_Name => New_Copy (Defining_Identifier (Formal)), + Name => New_Reference_To (Actual_Pack, Loc)); + + Set_Associated_Formal_Package (Defining_Unit_Name (Nod), + Defining_Identifier (Formal)); + Decls := New_List (Nod); + + -- If the formal F has a box, then the generic declarations are + -- visible in the generic G. In an instance of G, the corresponding + -- entities in the actual for F (which are the actuals for the + -- instantiation of the generic that F denotes) must also be made + -- visible for analysis of the current instance. On exit from the + -- current instance, those entities are made private again. If the + -- actual is currently in use, these entities are also use-visible. + + -- The loop through the actual entities also steps through the + -- formal entities and enters associations from formals to + -- actuals into the renaming map. This is necessary to properly + -- handle checking of actual parameter associations for later + -- formals that depend on actuals declared in the formal package. + -- + -- This processing needs to be reviewed at some point because + -- it is probably not entirely correct as written. For example + -- there may not be a strict one-to-one correspondence between + -- actuals and formals and this loop is currently assuming that + -- there is. ??? + + if Box_Present (Formal) then + declare + Actual_Ent : Entity_Id := First_Entity (Actual_Pack); + Formal_Node : Node_Id := Empty; + Formal_Ent : Entity_Id; + Gen_Decl : Node_Id := Unit_Declaration_Node (Gen_Parent); + Formals : List_Id := Generic_Formal_Declarations (Gen_Decl); + + begin + if Present (Formals) then + Formal_Node := First_Non_Pragma (Formals); + end if; + + while Present (Actual_Ent) + and then Actual_Ent /= First_Private_Entity (Actual_Pack) + loop + Set_Is_Hidden (Actual_Ent, False); + Set_Is_Potentially_Use_Visible + (Actual_Ent, In_Use (Actual_Pack)); + + if Present (Formal_Node) then + Formal_Ent := Formal_Entity (Formal_Node, Actual_Ent); + + if Present (Formal_Ent) then + Set_Instance_Of (Formal_Ent, Actual_Ent); + end if; + + Next_Non_Pragma (Formal_Node); + end if; + + Next_Entity (Actual_Ent); + end loop; + end; + + -- If the formal is not declared with a box, reanalyze it as + -- an instantiation, to verify the matching rules of 12.7. The + -- actual checks are performed after the generic associations + -- been analyzed. + + else + declare + I_Pack : constant Entity_Id := + Make_Defining_Identifier (Sloc (Actual), + Chars => New_Internal_Name ('P')); + + begin + Set_Is_Internal (I_Pack); + + Append_To (Decls, + Make_Package_Instantiation (Sloc (Actual), + Defining_Unit_Name => I_Pack, + Name => New_Occurrence_Of (Gen_Parent, Sloc (Actual)), + Generic_Associations => + Generic_Associations (Formal))); + end; + end if; + + return Decls; + end if; + + end Instantiate_Formal_Package; + + ----------------------------------- + -- Instantiate_Formal_Subprogram -- + ----------------------------------- + + function Instantiate_Formal_Subprogram + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return Node_Id + is + Loc : Source_Ptr := Sloc (Instantiation_Node); + Formal_Sub : constant Entity_Id := + Defining_Unit_Name (Specification (Formal)); + Analyzed_S : constant Entity_Id := + Defining_Unit_Name (Specification (Analyzed_Formal)); + Decl_Node : Node_Id; + Nam : Node_Id; + New_Spec : Node_Id; + + function From_Parent_Scope (Subp : Entity_Id) return Boolean; + -- If the generic is a child unit, the parent has been installed + -- on the scope stack, but a default subprogram cannot resolve to + -- something on the parent because that parent is not really part + -- of the visible context (it is there to resolve explicit local + -- entities). If the default has resolved in this way, we remove + -- the entity from immediate visibility and analyze the node again + -- to emit an error message or find another visible candidate. + + procedure Valid_Actual_Subprogram (Act : Node_Id); + -- Perform legality check and raise exception on failure. + + ----------------------- + -- From_Parent_Scope -- + ----------------------- + + function From_Parent_Scope (Subp : Entity_Id) return Boolean is + Gen_Scope : Node_Id := Scope (Analyzed_S); + + begin + while Present (Gen_Scope) + and then Is_Child_Unit (Gen_Scope) + loop + if Scope (Subp) = Scope (Gen_Scope) then + return True; + end if; + + Gen_Scope := Scope (Gen_Scope); + end loop; + + return False; + end From_Parent_Scope; + + ----------------------------- + -- Valid_Actual_Subprogram -- + ----------------------------- + + procedure Valid_Actual_Subprogram (Act : Node_Id) is + begin + if not Is_Entity_Name (Act) + and then Nkind (Act) /= N_Operator_Symbol + and then Nkind (Act) /= N_Attribute_Reference + and then Nkind (Act) /= N_Selected_Component + and then Nkind (Act) /= N_Indexed_Component + and then Nkind (Act) /= N_Character_Literal + and then Nkind (Act) /= N_Explicit_Dereference + then + if Etype (Act) /= Any_Type then + Error_Msg_NE + ("Expect subprogram name to instantiate &", + Instantiation_Node, Formal_Sub); + end if; + + -- In any case, instantiation cannot continue. + + Abandon_Instantiation (Instantiation_Node); + end if; + end Valid_Actual_Subprogram; + + -- Start of processing for Instantiate_Formal_Subprogram + + begin + New_Spec := New_Copy_Tree (Specification (Formal)); + + -- Create new entity for the actual (New_Copy_Tree does not). + + Set_Defining_Unit_Name + (New_Spec, Make_Defining_Identifier (Loc, Chars (Formal_Sub))); + + -- Find entity of actual. If the actual is an attribute reference, it + -- cannot be resolved here (its formal is missing) but is handled + -- instead in Attribute_Renaming. If the actual is overloaded, it is + -- fully resolved subsequently, when the renaming declaration for the + -- formal is analyzed. If it is an explicit dereference, resolve the + -- prefix but not the actual itself, to prevent interpretation as a + -- call. + + if Present (Actual) then + Loc := Sloc (Actual); + Set_Sloc (New_Spec, Loc); + + if Nkind (Actual) = N_Operator_Symbol then + Find_Direct_Name (Actual); + + elsif Nkind (Actual) = N_Explicit_Dereference then + Analyze (Prefix (Actual)); + + elsif Nkind (Actual) /= N_Attribute_Reference then + Analyze (Actual); + end if; + + Valid_Actual_Subprogram (Actual); + Nam := Actual; + + elsif Present (Default_Name (Formal)) then + + if Nkind (Default_Name (Formal)) /= N_Attribute_Reference + and then Nkind (Default_Name (Formal)) /= N_Selected_Component + and then Nkind (Default_Name (Formal)) /= N_Indexed_Component + and then Nkind (Default_Name (Formal)) /= N_Character_Literal + and then Present (Entity (Default_Name (Formal))) + then + Nam := New_Occurrence_Of (Entity (Default_Name (Formal)), Loc); + else + Nam := New_Copy (Default_Name (Formal)); + Set_Sloc (Nam, Loc); + end if; + + elsif Box_Present (Formal) then + + -- Actual is resolved at the point of instantiation. Create + -- an identifier or operator with the same name as the formal. + + if Nkind (Formal_Sub) = N_Defining_Operator_Symbol then + Nam := Make_Operator_Symbol (Loc, + Chars => Chars (Formal_Sub), + Strval => No_String); + else + Nam := Make_Identifier (Loc, Chars (Formal_Sub)); + end if; + + else + Error_Msg_NE + ("missing actual for instantiation of &", + Instantiation_Node, Formal_Sub); + Abandon_Instantiation (Instantiation_Node); + end if; + + Decl_Node := + Make_Subprogram_Renaming_Declaration (Loc, + Specification => New_Spec, + Name => Nam); + + -- Gather possible interpretations for the actual before analyzing the + -- instance. If overloaded, it will be resolved when analyzing the + -- renaming declaration. + + if Box_Present (Formal) + and then No (Actual) + then + Analyze (Nam); + + if Is_Child_Unit (Scope (Analyzed_S)) + and then Present (Entity (Nam)) + then + if not Is_Overloaded (Nam) then + + if From_Parent_Scope (Entity (Nam)) then + Set_Is_Immediately_Visible (Entity (Nam), False); + Set_Entity (Nam, Empty); + Set_Etype (Nam, Empty); + + Analyze (Nam); + + Set_Is_Immediately_Visible (Entity (Nam)); + end if; + + else + declare + I : Interp_Index; + It : Interp; + + begin + Get_First_Interp (Nam, I, It); + + while Present (It.Nam) loop + if From_Parent_Scope (It.Nam) then + Remove_Interp (I); + end if; + + Get_Next_Interp (I, It); + end loop; + end; + end if; + end if; + end if; + + -- The generic instantiation freezes the actual. This can only be + -- done once the actual is resolved, in the analysis of the renaming + -- declaration. To indicate that must be done, we set the corresponding + -- spec of the node to point to the formal subprogram declaration. + + Set_Corresponding_Spec (Decl_Node, Analyzed_Formal); + + -- We cannot analyze the renaming declaration, and thus find the + -- actual, until the all the actuals are assembled in the instance. + -- For subsequent checks of other actuals, indicate the node that + -- will hold the instance of this formal. + + Set_Instance_Of (Analyzed_S, Nam); + + if Nkind (Actual) = N_Selected_Component + and then Is_Task_Type (Etype (Prefix (Actual))) + and then not Is_Frozen (Etype (Prefix (Actual))) + then + -- The renaming declaration will create a body, which must appear + -- outside of the instantiation, We move the renaming declaration + -- out of the instance, and create an additional renaming inside, + -- to prevent freezing anomalies. + + declare + Anon_Id : constant Entity_Id := + Make_Defining_Identifier + (Loc, New_Internal_Name ('E')); + begin + Set_Defining_Unit_Name (New_Spec, Anon_Id); + Insert_Before (Instantiation_Node, Decl_Node); + Analyze (Decl_Node); + + -- Now create renaming within the instance. + + Decl_Node := + Make_Subprogram_Renaming_Declaration (Loc, + Specification => New_Copy_Tree (New_Spec), + Name => New_Occurrence_Of (Anon_Id, Loc)); + + Set_Defining_Unit_Name (Specification (Decl_Node), + Make_Defining_Identifier (Loc, Chars (Formal_Sub))); + end; + end if; + + return Decl_Node; + end Instantiate_Formal_Subprogram; + + ------------------------ + -- Instantiate_Object -- + ------------------------ + + function Instantiate_Object + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return List_Id + is + Formal_Id : constant Entity_Id := Defining_Identifier (Formal); + Type_Id : constant Node_Id := Subtype_Mark (Formal); + Loc : constant Source_Ptr := Sloc (Actual); + Act_Assoc : constant Node_Id := Parent (Actual); + Orig_Ftyp : constant Entity_Id := + Etype (Defining_Identifier (Analyzed_Formal)); + Ftyp : Entity_Id; + Decl_Node : Node_Id; + Subt_Decl : Node_Id := Empty; + List : List_Id := New_List; + + begin + if Get_Instance_Of (Formal_Id) /= Formal_Id then + Error_Msg_N ("duplicate instantiation of generic parameter", Actual); + end if; + + Set_Parent (List, Parent (Actual)); + + -- OUT present + + if Out_Present (Formal) then + + -- An IN OUT generic actual must be a name. The instantiation is + -- a renaming declaration. The actual is the name being renamed. + -- We use the actual directly, rather than a copy, because it is not + -- used further in the list of actuals, and because a copy or a use + -- of relocate_node is incorrect if the instance is nested within + -- a generic. In order to simplify ASIS searches, the Generic_Parent + -- field links the declaration to the generic association. + + if No (Actual) then + Error_Msg_NE + ("missing actual for instantiation of &", + Instantiation_Node, Formal_Id); + Abandon_Instantiation (Instantiation_Node); + end if; + + Decl_Node := + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => New_Copy (Formal_Id), + Subtype_Mark => New_Copy_Tree (Type_Id), + Name => Actual); + + Set_Corresponding_Generic_Association (Decl_Node, Act_Assoc); + + -- The analysis of the actual may produce insert_action nodes, so + -- the declaration must have a context in which to attach them. + + Append (Decl_Node, List); + Analyze (Actual); + + -- This check is performed here because Analyze_Object_Renaming + -- will not check it when Comes_From_Source is False. Note + -- though that the check for the actual being the name of an + -- object will be performed in Analyze_Object_Renaming. + + if Is_Object_Reference (Actual) + and then Is_Dependent_Component_Of_Mutable_Object (Actual) + then + Error_Msg_N + ("illegal discriminant-dependent component for in out parameter", + Actual); + end if; + + -- The actual has to be resolved in order to check that it is + -- a variable (due to cases such as F(1), where F returns + -- access to an array, and for overloaded prefixes). + + Ftyp := + Get_Instance_Of (Etype (Defining_Identifier (Analyzed_Formal))); + + if Is_Private_Type (Ftyp) + and then not Is_Private_Type (Etype (Actual)) + and then (Base_Type (Full_View (Ftyp)) = Base_Type (Etype (Actual)) + or else Base_Type (Etype (Actual)) = Ftyp) + then + -- If the actual has the type of the full view of the formal, + -- or else a non-private subtype of the formal, then + -- the visibility of the formal type has changed. Add to the + -- actuals a subtype declaration that will force the exchange + -- of views in the body of the instance as well. + + Subt_Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, New_Internal_Name ('P')), + Subtype_Indication => New_Occurrence_Of (Ftyp, Loc)); + + Prepend (Subt_Decl, List); + + Append_Elmt (Full_View (Ftyp), Exchanged_Views); + Exchange_Declarations (Ftyp); + end if; + + Resolve (Actual, Ftyp); + + if not Is_Variable (Actual) or else Paren_Count (Actual) > 0 then + Error_Msg_NE + ("actual for& must be a variable", Actual, Formal_Id); + + elsif Base_Type (Ftyp) /= Base_Type (Etype (Actual)) then + Error_Msg_NE ( + "type of actual does not match type of&", Actual, Formal_Id); + + end if; + + Note_Possible_Modification (Actual); + + -- Check for instantiation of atomic/volatile actual for + -- non-atomic/volatile formal (RM C.6 (12)). + + if Is_Atomic_Object (Actual) + and then not Is_Atomic (Orig_Ftyp) + then + Error_Msg_N + ("cannot instantiate non-atomic formal object " & + "with atomic actual", Actual); + + elsif Is_Volatile_Object (Actual) + and then not Is_Volatile (Orig_Ftyp) + then + Error_Msg_N + ("cannot instantiate non-volatile formal object " & + "with volatile actual", Actual); + end if; + + -- OUT not present + + else + -- The instantiation of a generic formal in-parameter + -- is a constant declaration. The actual is the expression for + -- that declaration. + + if Present (Actual) then + + Decl_Node := Make_Object_Declaration (Loc, + Defining_Identifier => New_Copy (Formal_Id), + Constant_Present => True, + Object_Definition => New_Copy_Tree (Type_Id), + Expression => Actual); + + Set_Corresponding_Generic_Association (Decl_Node, Act_Assoc); + + -- A generic formal object of a tagged type is defined + -- to be aliased so the new constant must also be treated + -- as aliased. + + if Is_Tagged_Type + (Etype (Defining_Identifier (Analyzed_Formal))) + then + Set_Aliased_Present (Decl_Node); + end if; + + Append (Decl_Node, List); + Analyze (Actual); + + declare + Typ : Entity_Id + := Get_Instance_Of + (Etype (Defining_Identifier (Analyzed_Formal))); + begin + Freeze_Before (Instantiation_Node, Typ); + + -- If the actual is an aggregate, perform name resolution + -- on its components (the analysis of an aggregate does not + -- do it) to capture local names that may be hidden if the + -- generic is a child unit. + + if Nkind (Actual) = N_Aggregate then + Pre_Analyze_And_Resolve (Actual, Typ); + end if; + end; + + elsif Present (Expression (Formal)) then + + -- Use default to construct declaration. + + Decl_Node := + Make_Object_Declaration (Sloc (Formal), + Defining_Identifier => New_Copy (Formal_Id), + Constant_Present => True, + Object_Definition => New_Copy (Type_Id), + Expression => New_Copy_Tree (Expression (Formal))); + + Append (Decl_Node, List); + Set_Analyzed (Expression (Decl_Node), False); + + else + Error_Msg_NE + ("missing actual for instantiation of &", + Instantiation_Node, Formal_Id); + Abandon_Instantiation (Instantiation_Node); + end if; + + end if; + + return List; + end Instantiate_Object; + + ------------------------------ + -- Instantiate_Package_Body -- + ------------------------------ + + procedure Instantiate_Package_Body + (Body_Info : Pending_Body_Info) + is + Act_Decl : constant Node_Id := Body_Info.Act_Decl; + Inst_Node : constant Node_Id := Body_Info.Inst_Node; + Loc : constant Source_Ptr := Sloc (Inst_Node); + + Gen_Id : constant Node_Id := Name (Inst_Node); + Gen_Unit : constant Entity_Id := Entity (Name (Inst_Node)); + Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Unit); + Act_Spec : constant Node_Id := Specification (Act_Decl); + Act_Decl_Id : constant Entity_Id := Defining_Entity (Act_Spec); + + Act_Body_Name : Node_Id; + Gen_Body : Node_Id; + Gen_Body_Id : Node_Id; + Act_Body : Node_Id; + Act_Body_Id : Entity_Id; + + Parent_Installed : Boolean := False; + Save_Style_Check : Boolean := Style_Check; + + begin + Gen_Body_Id := Corresponding_Body (Gen_Decl); + Expander_Mode_Save_And_Set (Body_Info.Expander_Status); + + if No (Gen_Body_Id) then + Load_Parent_Of_Generic (Inst_Node, Specification (Gen_Decl)); + Gen_Body_Id := Corresponding_Body (Gen_Decl); + end if; + + -- Establish global variable for sloc adjustment and for error + -- recovery. + + Instantiation_Node := Inst_Node; + + if Present (Gen_Body_Id) then + Save_Env (Gen_Unit, Act_Decl_Id); + Style_Check := False; + Current_Sem_Unit := Body_Info.Current_Sem_Unit; + + Gen_Body := Unit_Declaration_Node (Gen_Body_Id); + + Create_Instantiation_Source + (Inst_Node, Gen_Body_Id, S_Adjustment); + + Act_Body := + Copy_Generic_Node + (Original_Node (Gen_Body), Empty, Instantiating => True); + + -- Build new name (possibly qualified) for body declaration. + + Act_Body_Id := New_Copy (Act_Decl_Id); + + -- Some attributes of the spec entity are not inherited by the + -- body entity. + + Set_Handler_Records (Act_Body_Id, No_List); + + if Nkind (Defining_Unit_Name (Act_Spec)) = + N_Defining_Program_Unit_Name + then + Act_Body_Name := + Make_Defining_Program_Unit_Name (Loc, + Name => New_Copy_Tree (Name (Defining_Unit_Name (Act_Spec))), + Defining_Identifier => Act_Body_Id); + else + Act_Body_Name := Act_Body_Id; + end if; + + Set_Defining_Unit_Name (Act_Body, Act_Body_Name); + + Set_Corresponding_Spec (Act_Body, Act_Decl_Id); + Check_Generic_Actuals (Act_Decl_Id, False); + + -- If it is a child unit, make the parent instance (which is an + -- instance of the parent of the generic) visible. The parent + -- instance is the prefix of the name of the generic unit. + + if Ekind (Scope (Gen_Unit)) = E_Generic_Package + and then Nkind (Gen_Id) = N_Expanded_Name + then + Install_Parent (Entity (Prefix (Gen_Id)), In_Body => True); + Parent_Installed := True; + + elsif Is_Child_Unit (Gen_Unit) then + Install_Parent (Scope (Gen_Unit), In_Body => True); + Parent_Installed := True; + end if; + + -- If the instantiation is a library unit, and this is the main + -- unit, then build the resulting compilation unit nodes for the + -- instance. If this is a compilation unit but it is not the main + -- unit, then it is the body of a unit in the context, that is being + -- compiled because it is encloses some inlined unit or another + -- generic unit being instantiated. In that case, this body is not + -- part of the current compilation, and is not attached to the tree, + -- but its parent must be set for analysis. + + if Nkind (Parent (Inst_Node)) = N_Compilation_Unit then + + if Parent (Inst_Node) = Cunit (Main_Unit) then + Build_Instance_Compilation_Unit_Nodes + (Inst_Node, Act_Body, Act_Decl); + Analyze (Inst_Node); + + -- If the instance is a child unit itself, then set the + -- scope of the expanded body to be the parent of the + -- instantiation (ensuring that the fully qualified name + -- will be generated for the elaboration subprogram). + + if Nkind (Defining_Unit_Name (Act_Spec)) = + N_Defining_Program_Unit_Name + then + Set_Scope + (Defining_Entity (Inst_Node), Scope (Act_Decl_Id)); + end if; + + else + Set_Parent (Act_Body, Parent (Inst_Node)); + Analyze (Act_Body); + end if; + + -- Case where instantiation is not a library unit + + else + -- If this is an early instantiation, i.e. appears textually + -- before the corresponding body and must be elaborated first, + -- indicate that the body instance is to be delayed. + + Install_Body (Act_Body, Inst_Node, Gen_Body, Gen_Decl); + + -- Now analyze the body. We turn off all checks if this is + -- an internal unit, since there is no reason to have checks + -- on for any predefined run-time library code. All such + -- code is designed to be compiled with checks off. + + -- Note that we do NOT apply this criterion to children of + -- GNAT (or on VMS, children of DEC). The latter units must + -- suppress checks explicitly if this is needed. + + if Is_Predefined_File_Name + (Unit_File_Name (Get_Source_Unit (Gen_Decl))) + then + Analyze (Act_Body, Suppress => All_Checks); + else + Analyze (Act_Body); + end if; + end if; + + if not Generic_Separately_Compiled (Gen_Unit) then + Inherit_Context (Gen_Body, Inst_Node); + end if; + + Restore_Private_Views (Act_Decl_Id); + Restore_Env; + Style_Check := Save_Style_Check; + + -- If we have no body, and the unit requires a body, then complain. + -- This complaint is suppressed if we have detected other errors + -- (since a common reason for missing the body is that it had errors). + + elsif Unit_Requires_Body (Gen_Unit) then + if Errors_Detected = 0 then + Error_Msg_NE + ("cannot find body of generic package &", Inst_Node, Gen_Unit); + + -- Don't attempt to perform any cleanup actions if some other + -- error was aready detected, since this can cause blowups. + + else + return; + end if; + + -- Case of package that does not need a body + + else + -- If the instantiation of the declaration is a library unit, + -- rewrite the original package instantiation as a package + -- declaration in the compilation unit node. + + if Nkind (Parent (Inst_Node)) = N_Compilation_Unit then + Set_Parent_Spec (Act_Decl, Parent_Spec (Inst_Node)); + Rewrite (Inst_Node, Act_Decl); + + -- If the instantiation is not a library unit, then append the + -- declaration to the list of implicitly generated entities. + -- unless it is already a list member which means that it was + -- already processed + + elsif not Is_List_Member (Act_Decl) then + Mark_Rewrite_Insertion (Act_Decl); + Insert_Before (Inst_Node, Act_Decl); + end if; + end if; + + Expander_Mode_Restore; + + -- Remove the parent instances if they have been placed on the + -- scope stack to compile the body. + + if Parent_Installed then + Remove_Parent (In_Body => True); + end if; + end Instantiate_Package_Body; + + --------------------------------- + -- Instantiate_Subprogram_Body -- + --------------------------------- + + procedure Instantiate_Subprogram_Body + (Body_Info : Pending_Body_Info) + is + Act_Decl : constant Node_Id := Body_Info.Act_Decl; + Inst_Node : constant Node_Id := Body_Info.Inst_Node; + Loc : constant Source_Ptr := Sloc (Inst_Node); + + Decls : List_Id; + Gen_Id : constant Node_Id := Name (Inst_Node); + Gen_Unit : constant Entity_Id := Entity (Name (Inst_Node)); + Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Unit); + Anon_Id : constant Entity_Id := + Defining_Unit_Name (Specification (Act_Decl)); + Gen_Body : Node_Id; + Gen_Body_Id : Node_Id; + Act_Body : Node_Id; + Act_Body_Id : Entity_Id; + Pack_Id : Entity_Id := Defining_Unit_Name (Parent (Act_Decl)); + Pack_Body : Node_Id; + Prev_Formal : Entity_Id; + Unit_Renaming : Node_Id; + + Parent_Installed : Boolean := False; + Save_Style_Check : Boolean := Style_Check; + + begin + Gen_Body_Id := Corresponding_Body (Gen_Decl); + + Expander_Mode_Save_And_Set (Body_Info.Expander_Status); + + if No (Gen_Body_Id) then + Load_Parent_Of_Generic (Inst_Node, Specification (Gen_Decl)); + Gen_Body_Id := Corresponding_Body (Gen_Decl); + end if; + + Instantiation_Node := Inst_Node; + + if Present (Gen_Body_Id) then + Gen_Body := Unit_Declaration_Node (Gen_Body_Id); + + if Nkind (Gen_Body) = N_Subprogram_Body_Stub then + + -- Either body is not present, or context is non-expanding, as + -- when compiling a subunit. Mark the instance as completed. + + Set_Has_Completion (Anon_Id); + return; + end if; + + Save_Env (Gen_Unit, Anon_Id); + Style_Check := False; + Current_Sem_Unit := Body_Info.Current_Sem_Unit; + Create_Instantiation_Source (Inst_Node, Gen_Body_Id, S_Adjustment); + + Act_Body := + Copy_Generic_Node + (Original_Node (Gen_Body), Empty, Instantiating => True); + Act_Body_Id := Defining_Entity (Act_Body); + Set_Chars (Act_Body_Id, Chars (Anon_Id)); + Set_Sloc (Act_Body_Id, Sloc (Defining_Entity (Inst_Node))); + Set_Corresponding_Spec (Act_Body, Anon_Id); + Set_Has_Completion (Anon_Id); + Check_Generic_Actuals (Pack_Id, False); + + -- If it is a child unit, make the parent instance (which is an + -- instance of the parent of the generic) visible. The parent + -- instance is the prefix of the name of the generic unit. + + if Ekind (Scope (Gen_Unit)) = E_Generic_Package + and then Nkind (Gen_Id) = N_Expanded_Name + then + Install_Parent (Entity (Prefix (Gen_Id)), In_Body => True); + Parent_Installed := True; + + elsif Is_Child_Unit (Gen_Unit) then + Install_Parent (Scope (Gen_Unit), In_Body => True); + Parent_Installed := True; + end if; + + -- Inside its body, a reference to the generic unit is a reference + -- to the instance. The corresponding renaming is the first + -- declaration in the body. + + Unit_Renaming := + Make_Subprogram_Renaming_Declaration (Loc, + Specification => + Copy_Generic_Node ( + Specification (Original_Node (Gen_Body)), + Empty, + Instantiating => True), + Name => New_Occurrence_Of (Anon_Id, Loc)); + + -- If there is a formal subprogram with the same name as the + -- unit itself, do not add this renaming declaration. This is + -- a temporary fix for one ACVC test. ??? + + Prev_Formal := First_Entity (Pack_Id); + while Present (Prev_Formal) loop + if Chars (Prev_Formal) = Chars (Gen_Unit) + and then Is_Overloadable (Prev_Formal) + then + exit; + end if; + + Next_Entity (Prev_Formal); + end loop; + + if Present (Prev_Formal) then + Decls := New_List (Act_Body); + else + Decls := New_List (Unit_Renaming, Act_Body); + end if; + + -- The subprogram body is placed in the body of a dummy package + -- body, whose spec contains the subprogram declaration as well + -- as the renaming declarations for the generic parameters. + + Pack_Body := Make_Package_Body (Loc, + Defining_Unit_Name => New_Copy (Pack_Id), + Declarations => Decls); + + Set_Corresponding_Spec (Pack_Body, Pack_Id); + + -- If the instantiation is a library unit, then build resulting + -- compilation unit nodes for the instance. The declaration of + -- the enclosing package is the grandparent of the subprogram + -- declaration. First replace the instantiation node as the unit + -- of the corresponding compilation. + + if Nkind (Parent (Inst_Node)) = N_Compilation_Unit then + + if Parent (Inst_Node) = Cunit (Main_Unit) then + Set_Unit (Parent (Inst_Node), Inst_Node); + Build_Instance_Compilation_Unit_Nodes + (Inst_Node, Pack_Body, Parent (Parent (Act_Decl))); + Analyze (Inst_Node); + else + Set_Parent (Pack_Body, Parent (Inst_Node)); + Analyze (Pack_Body); + end if; + + else + Insert_Before (Inst_Node, Pack_Body); + Mark_Rewrite_Insertion (Pack_Body); + Analyze (Pack_Body); + + if Expander_Active then + Freeze_Subprogram_Body (Inst_Node, Gen_Body, Pack_Id); + end if; + end if; + + if not Generic_Separately_Compiled (Gen_Unit) then + Inherit_Context (Gen_Body, Inst_Node); + end if; + + Restore_Private_Views (Pack_Id, False); + + if Parent_Installed then + Remove_Parent (In_Body => True); + end if; + + Restore_Env; + Style_Check := Save_Style_Check; + + -- Body not found. Error was emitted already. If there were no + -- previous errors, this may be an instance whose scope is a premature + -- instance. In that case we must insure that the (legal) program does + -- raise program error if executed. We generate a subprogram body for + -- this purpose. See DEC ac30vso. + + elsif Errors_Detected = 0 + and then Nkind (Parent (Inst_Node)) /= N_Compilation_Unit + then + if Ekind (Anon_Id) = E_Procedure then + Act_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Procedure_Specification (Loc, + Defining_Unit_Name => New_Copy (Anon_Id), + Parameter_Specifications => + New_Copy_List + (Parameter_Specifications (Parent (Anon_Id)))), + + Declarations => Empty_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => + New_List (Make_Raise_Program_Error (Loc)))); + else + Act_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Function_Specification (Loc, + Defining_Unit_Name => New_Copy (Anon_Id), + Parameter_Specifications => + New_Copy_List + (Parameter_Specifications (Parent (Anon_Id))), + Subtype_Mark => + New_Occurrence_Of (Etype (Anon_Id), Loc)), + + Declarations => Empty_List, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Make_Return_Statement (Loc, + Expression => Make_Raise_Program_Error (Loc))))); + end if; + + Pack_Body := Make_Package_Body (Loc, + Defining_Unit_Name => New_Copy (Pack_Id), + Declarations => New_List (Act_Body)); + + Insert_After (Inst_Node, Pack_Body); + Set_Corresponding_Spec (Pack_Body, Pack_Id); + Analyze (Pack_Body); + end if; + + Expander_Mode_Restore; + end Instantiate_Subprogram_Body; + + ---------------------- + -- Instantiate_Type -- + ---------------------- + + function Instantiate_Type + (Formal : Node_Id; + Actual : Node_Id; + Analyzed_Formal : Node_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (Actual); + Gen_T : constant Entity_Id := Defining_Identifier (Formal); + A_Gen_T : constant Entity_Id := Defining_Identifier (Analyzed_Formal); + Ancestor : Entity_Id; + Def : constant Node_Id := Formal_Type_Definition (Formal); + Act_T : Entity_Id; + Decl_Node : Node_Id; + + procedure Validate_Array_Type_Instance; + procedure Validate_Access_Subprogram_Instance; + procedure Validate_Access_Type_Instance; + procedure Validate_Derived_Type_Instance; + procedure Validate_Private_Type_Instance; + -- These procedures perform validation tests for the named case + + function Subtypes_Match (Gen_T, Act_T : Entity_Id) return Boolean; + -- Check that base types are the same and that the subtypes match + -- statically. Used in several of the above. + + -------------------- + -- Subtypes_Match -- + -------------------- + + function Subtypes_Match (Gen_T, Act_T : Entity_Id) return Boolean is + T : constant Entity_Id := Get_Instance_Of (Gen_T); + + begin + return (Base_Type (T) = Base_Type (Act_T) +-- why is the and then commented out here??? +-- and then Is_Constrained (T) = Is_Constrained (Act_T) + and then Subtypes_Statically_Match (T, Act_T)) + + or else (Is_Class_Wide_Type (Gen_T) + and then Is_Class_Wide_Type (Act_T) + and then + Subtypes_Match ( + Get_Instance_Of (Root_Type (Gen_T)), + Root_Type (Act_T))); + end Subtypes_Match; + + ----------------------------------------- + -- Validate_Access_Subprogram_Instance -- + ----------------------------------------- + + procedure Validate_Access_Subprogram_Instance is + begin + if not Is_Access_Type (Act_T) + or else Ekind (Designated_Type (Act_T)) /= E_Subprogram_Type + then + Error_Msg_NE + ("expect access type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Check_Mode_Conformant + (Designated_Type (Act_T), + Designated_Type (A_Gen_T), + Actual, + Get_Inst => True); + + if Ekind (Base_Type (Act_T)) = E_Access_Protected_Subprogram_Type then + if Ekind (A_Gen_T) = E_Access_Subprogram_Type then + Error_Msg_NE + ("protected access type not allowed for formal &", + Actual, Gen_T); + end if; + + elsif Ekind (A_Gen_T) = E_Access_Protected_Subprogram_Type then + Error_Msg_NE + ("expect protected access type for formal &", + Actual, Gen_T); + end if; + end Validate_Access_Subprogram_Instance; + + ----------------------------------- + -- Validate_Access_Type_Instance -- + ----------------------------------- + + procedure Validate_Access_Type_Instance is + Desig_Type : Entity_Id := + Find_Actual_Type (Designated_Type (A_Gen_T), Scope (A_Gen_T)); + + begin + if not Is_Access_Type (Act_T) then + Error_Msg_NE + ("expect access type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + if Is_Access_Constant (A_Gen_T) then + if not Is_Access_Constant (Act_T) then + Error_Msg_N + ("actual type must be access-to-constant type", Actual); + Abandon_Instantiation (Actual); + end if; + else + if Is_Access_Constant (Act_T) then + Error_Msg_N + ("actual type must be access-to-variable type", Actual); + Abandon_Instantiation (Actual); + + elsif Ekind (A_Gen_T) = E_General_Access_Type + and then Ekind (Base_Type (Act_T)) /= E_General_Access_Type + then + Error_Msg_N ("actual must be general access type!", Actual); + Error_Msg_NE ("add ALL to }!", Actual, Act_T); + Abandon_Instantiation (Actual); + end if; + end if; + + -- The designated subtypes, that is to say the subtypes introduced + -- by an access type declaration (and not by a subtype declaration) + -- must match. + + if not Subtypes_Match + (Desig_Type, Designated_Type (Base_Type (Act_T))) + then + Error_Msg_NE + ("designated type of actual does not match that of formal &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Is_Access_Type (Designated_Type (Act_T)) + and then Is_Constrained (Designated_Type (Designated_Type (Act_T))) + /= + Is_Constrained (Designated_Type (Desig_Type)) + then + Error_Msg_NE + ("designated type of actual does not match that of formal &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + end Validate_Access_Type_Instance; + + ---------------------------------- + -- Validate_Array_Type_Instance -- + ---------------------------------- + + procedure Validate_Array_Type_Instance is + I1 : Node_Id; + I2 : Node_Id; + T2 : Entity_Id; + + function Formal_Dimensions return Int; + -- Count number of dimensions in array type formal + + function Formal_Dimensions return Int is + Num : Int := 0; + Index : Node_Id; + + begin + if Nkind (Def) = N_Constrained_Array_Definition then + Index := First (Discrete_Subtype_Definitions (Def)); + else + Index := First (Subtype_Marks (Def)); + end if; + + while Present (Index) loop + Num := Num + 1; + Next_Index (Index); + end loop; + + return Num; + end Formal_Dimensions; + + -- Start of processing for Validate_Array_Type_Instance + + begin + if not Is_Array_Type (Act_T) then + Error_Msg_NE + ("expect array type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Nkind (Def) = N_Constrained_Array_Definition then + if not (Is_Constrained (Act_T)) then + Error_Msg_NE + ("expect constrained array in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + else + if Is_Constrained (Act_T) then + Error_Msg_NE + ("expect unconstrained array in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + end if; + + if Formal_Dimensions /= Number_Dimensions (Act_T) then + Error_Msg_NE + ("dimensions of actual do not match formal &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + I1 := First_Index (A_Gen_T); + I2 := First_Index (Act_T); + for J in 1 .. Formal_Dimensions loop + + -- If the indices of the actual were given by a subtype_mark, + -- the index was transformed into a range attribute. Retrieve + -- the original type mark for checking. + + if Is_Entity_Name (Original_Node (I2)) then + T2 := Entity (Original_Node (I2)); + else + T2 := Etype (I2); + end if; + + if not Subtypes_Match + (Find_Actual_Type (Etype (I1), Scope (A_Gen_T)), T2) + then + Error_Msg_NE + ("index types of actual do not match those of formal &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Next_Index (I1); + Next_Index (I2); + end loop; + + if not Subtypes_Match ( + Find_Actual_Type (Component_Type (A_Gen_T), Scope (A_Gen_T)), + Component_Type (Act_T)) + then + Error_Msg_NE + ("component subtype of actual does not match that of formal &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + if Has_Aliased_Components (A_Gen_T) + and then not Has_Aliased_Components (Act_T) + then + Error_Msg_NE + ("actual must have aliased components to match formal type &", + Actual, Gen_T); + end if; + + end Validate_Array_Type_Instance; + + ------------------------------------ + -- Validate_Derived_Type_Instance -- + ------------------------------------ + + procedure Validate_Derived_Type_Instance is + Actual_Discr : Entity_Id; + Ancestor_Discr : Entity_Id; + + begin + -- If the parent type in the generic declaration is itself + -- a previous formal type, then it is local to the generic + -- and absent from the analyzed generic definition. In that + -- case the ancestor is the instance of the formal (which must + -- have been instantiated previously). Otherwise, the analyzed + -- generic carries the parent type. If the parent type is defined + -- in a previous formal package, then the scope of that formal + -- package is that of the generic type itself, and it has already + -- been mapped into the corresponding type in the actual package. + + -- Common case: parent type defined outside of the generic. + + if Is_Entity_Name (Subtype_Mark (Def)) + and then Present (Entity (Subtype_Mark (Def))) + then + Ancestor := Get_Instance_Of (Entity (Subtype_Mark (Def))); + + -- Check whether parent is defined in a previous formal package. + + elsif + Scope (Scope (Base_Type (Etype (A_Gen_T)))) = Scope (A_Gen_T) + then + Ancestor := + Get_Instance_Of (Base_Type (Etype (A_Gen_T))); + + elsif Is_Derived_Type (Get_Instance_Of (A_Gen_T)) then + Ancestor := + Get_Instance_Of (Base_Type (Get_Instance_Of (A_Gen_T))); + + else + Ancestor := Get_Instance_Of (Etype (Base_Type (A_Gen_T))); + end if; + + if not Is_Ancestor (Base_Type (Ancestor), Act_T) then + Error_Msg_NE + ("expect type derived from & in instantiation", + Actual, First_Subtype (Ancestor)); + Abandon_Instantiation (Actual); + end if; + + -- Perform atomic/volatile checks (RM C.6(12)) + + if Is_Atomic (Act_T) and then not Is_Atomic (Ancestor) then + Error_Msg_N + ("cannot have atomic actual type for non-atomic formal type", + Actual); + + elsif Is_Volatile (Act_T) + and then not Is_Volatile (Ancestor) + and then Is_By_Reference_Type (Ancestor) + then + Error_Msg_N + ("cannot have volatile actual type for non-volatile formal type", + Actual); + end if; + + -- It should not be necessary to check for unknown discriminants + -- on Formal, but for some reason Has_Unknown_Discriminants is + -- false for A_Gen_T, so Is_Indefinite_Subtype incorrectly + -- returns False. This needs fixing. ??? + + if not Is_Indefinite_Subtype (A_Gen_T) + and then not Unknown_Discriminants_Present (Formal) + and then Is_Indefinite_Subtype (Act_T) + then + Error_Msg_N + ("actual subtype must be constrained", Actual); + Abandon_Instantiation (Actual); + end if; + + if not Unknown_Discriminants_Present (Formal) then + if Is_Constrained (Ancestor) then + if not Is_Constrained (Act_T) then + Error_Msg_N + ("actual subtype must be constrained", Actual); + Abandon_Instantiation (Actual); + end if; + + -- Ancestor is unconstrained + + elsif Is_Constrained (Act_T) then + if Ekind (Ancestor) = E_Access_Type + or else Is_Composite_Type (Ancestor) + then + Error_Msg_N + ("actual subtype must be unconstrained", Actual); + Abandon_Instantiation (Actual); + end if; + + -- A class-wide type is only allowed if the formal has + -- unknown discriminants. + + elsif Is_Class_Wide_Type (Act_T) + and then not Has_Unknown_Discriminants (Ancestor) + then + Error_Msg_NE + ("actual for & cannot be a class-wide type", Actual, Gen_T); + Abandon_Instantiation (Actual); + + -- Otherwise, the formal and actual shall have the same + -- number of discriminants and each discriminant of the + -- actual must correspond to a discriminant of the formal. + + elsif Has_Discriminants (Act_T) + and then Has_Discriminants (Ancestor) + then + Actual_Discr := First_Discriminant (Act_T); + Ancestor_Discr := First_Discriminant (Ancestor); + while Present (Actual_Discr) + and then Present (Ancestor_Discr) + loop + if Base_Type (Act_T) /= Base_Type (Ancestor) and then + not Present (Corresponding_Discriminant (Actual_Discr)) + then + Error_Msg_NE + ("discriminant & does not correspond " & + "to ancestor discriminant", Actual, Actual_Discr); + Abandon_Instantiation (Actual); + end if; + + Next_Discriminant (Actual_Discr); + Next_Discriminant (Ancestor_Discr); + end loop; + + if Present (Actual_Discr) or else Present (Ancestor_Discr) then + Error_Msg_NE + ("actual for & must have same number of discriminants", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + -- This case should be caught by the earlier check for + -- for constrainedness, but the check here is added for + -- completeness. + + elsif Has_Discriminants (Act_T) then + Error_Msg_NE + ("actual for & must not have discriminants", Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Has_Discriminants (Ancestor) then + Error_Msg_NE + ("actual for & must have known discriminants", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + if not Subtypes_Statically_Compatible (Act_T, Ancestor) then + Error_Msg_N + ("constraint on actual is incompatible with formal", Actual); + Abandon_Instantiation (Actual); + end if; + end if; + + end Validate_Derived_Type_Instance; + + ------------------------------------ + -- Validate_Private_Type_Instance -- + ------------------------------------ + + procedure Validate_Private_Type_Instance is + Formal_Discr : Entity_Id; + Actual_Discr : Entity_Id; + Formal_Subt : Entity_Id; + + begin + if (Is_Limited_Type (Act_T) + or else Is_Limited_Composite (Act_T)) + and then not Is_Limited_Type (A_Gen_T) + then + Error_Msg_NE + ("actual for non-limited & cannot be a limited type", Actual, + Gen_T); + Abandon_Instantiation (Actual); + + elsif Is_Indefinite_Subtype (Act_T) + and then not Is_Indefinite_Subtype (A_Gen_T) + and then Ada_95 + then + Error_Msg_NE + ("actual for & must be a definite subtype", Actual, Gen_T); + + elsif not Is_Tagged_Type (Act_T) + and then Is_Tagged_Type (A_Gen_T) + then + Error_Msg_NE + ("actual for & must be a tagged type", Actual, Gen_T); + + elsif Has_Discriminants (A_Gen_T) then + if not Has_Discriminants (Act_T) then + Error_Msg_NE + ("actual for & must have discriminants", Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif Is_Constrained (Act_T) then + Error_Msg_NE + ("actual for & must be unconstrained", Actual, Gen_T); + Abandon_Instantiation (Actual); + + else + Formal_Discr := First_Discriminant (A_Gen_T); + Actual_Discr := First_Discriminant (Act_T); + while Formal_Discr /= Empty loop + if Actual_Discr = Empty then + Error_Msg_NE + ("discriminants on actual do not match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Formal_Subt := Get_Instance_Of (Etype (Formal_Discr)); + + -- access discriminants match if designated types do. + + if Ekind (Base_Type (Formal_Subt)) = E_Anonymous_Access_Type + and then (Ekind (Base_Type (Etype (Actual_Discr)))) + = E_Anonymous_Access_Type + and then Get_Instance_Of ( + Designated_Type (Base_Type (Formal_Subt))) + = Designated_Type (Base_Type (Etype (Actual_Discr))) + then + null; + + elsif Base_Type (Formal_Subt) /= + Base_Type (Etype (Actual_Discr)) + then + Error_Msg_NE + ("types of actual discriminants must match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + + elsif not Subtypes_Statically_Match + (Formal_Subt, Etype (Actual_Discr)) + and then Ada_95 + then + Error_Msg_NE + ("subtypes of actual discriminants must match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + Next_Discriminant (Formal_Discr); + Next_Discriminant (Actual_Discr); + end loop; + + if Actual_Discr /= Empty then + Error_Msg_NE + ("discriminants on actual do not match formal", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + end if; + + end if; + + Ancestor := Gen_T; + end Validate_Private_Type_Instance; + + -- Start of processing for Instantiate_Type + + begin + if Get_Instance_Of (A_Gen_T) /= A_Gen_T then + Error_Msg_N ("duplicate instantiation of generic type", Actual); + return Error; + + elsif not Is_Entity_Name (Actual) + or else not Is_Type (Entity (Actual)) + then + Error_Msg_NE + ("expect valid subtype mark to instantiate &", Actual, Gen_T); + Abandon_Instantiation (Actual); + + else + Act_T := Entity (Actual); + + if Ekind (Act_T) = E_Incomplete_Type then + if No (Underlying_Type (Act_T)) then + Error_Msg_N ("premature use of incomplete type", Actual); + Abandon_Instantiation (Actual); + else + Act_T := Full_View (Act_T); + Set_Entity (Actual, Act_T); + + if Has_Private_Component (Act_T) then + Error_Msg_N + ("premature use of type with private component", Actual); + end if; + end if; + + elsif Is_Private_Type (Act_T) + and then Is_Private_Type (Base_Type (Act_T)) + and then not Is_Generic_Type (Act_T) + and then not Is_Derived_Type (Act_T) + and then No (Full_View (Root_Type (Act_T))) + then + Error_Msg_N ("premature use of private type", Actual); + + elsif Has_Private_Component (Act_T) then + Error_Msg_N + ("premature use of type with private component", Actual); + end if; + + Set_Instance_Of (A_Gen_T, Act_T); + + -- If the type is generic, the class-wide type may also be used + + if Is_Tagged_Type (A_Gen_T) + and then Is_Tagged_Type (Act_T) + and then not Is_Class_Wide_Type (A_Gen_T) + then + Set_Instance_Of (Class_Wide_Type (A_Gen_T), + Class_Wide_Type (Act_T)); + end if; + + if not Is_Abstract (A_Gen_T) + and then Is_Abstract (Act_T) + then + Error_Msg_N + ("actual of non-abstract formal cannot be abstract", Actual); + end if; + + if Is_Scalar_Type (Gen_T) then + Set_Instance_Of (Etype (A_Gen_T), Etype (Act_T)); + end if; + end if; + + case Nkind (Def) is + when N_Formal_Private_Type_Definition => + Validate_Private_Type_Instance; + + when N_Formal_Derived_Type_Definition => + Validate_Derived_Type_Instance; + + when N_Formal_Discrete_Type_Definition => + if not Is_Discrete_Type (Act_T) then + Error_Msg_NE + ("expect discrete type in instantiation of&", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Signed_Integer_Type_Definition => + if not Is_Signed_Integer_Type (Act_T) then + Error_Msg_NE + ("expect signed integer type in instantiation of&", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Modular_Type_Definition => + if not Is_Modular_Integer_Type (Act_T) then + Error_Msg_NE + ("expect modular type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Floating_Point_Definition => + if not Is_Floating_Point_Type (Act_T) then + Error_Msg_NE + ("expect float type in instantiation of &", Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Ordinary_Fixed_Point_Definition => + if not Is_Ordinary_Fixed_Point_Type (Act_T) then + Error_Msg_NE + ("expect ordinary fixed point type in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Formal_Decimal_Fixed_Point_Definition => + if not Is_Decimal_Fixed_Point_Type (Act_T) then + Error_Msg_NE + ("expect decimal type in instantiation of &", + Actual, Gen_T); + Abandon_Instantiation (Actual); + end if; + + when N_Array_Type_Definition => + Validate_Array_Type_Instance; + + when N_Access_To_Object_Definition => + Validate_Access_Type_Instance; + + when N_Access_Function_Definition | + N_Access_Procedure_Definition => + Validate_Access_Subprogram_Instance; + + when others => + raise Program_Error; + + end case; + + Decl_Node := + Make_Subtype_Declaration (Loc, + Defining_Identifier => New_Copy (Gen_T), + Subtype_Indication => New_Reference_To (Act_T, Loc)); + + if Is_Private_Type (Act_T) then + Set_Has_Private_View (Subtype_Indication (Decl_Node)); + end if; + + -- Flag actual derived types so their elaboration produces the + -- appropriate renamings for the primitive operations of the ancestor. + -- Flag actual for formal private types as well, to determine whether + -- operations in the private part may override inherited operations. + + if Nkind (Def) = N_Formal_Derived_Type_Definition + or else Nkind (Def) = N_Formal_Private_Type_Definition + then + Set_Generic_Parent_Type (Decl_Node, Ancestor); + end if; + + return Decl_Node; + end Instantiate_Type; + + --------------------- + -- Is_In_Main_Unit -- + --------------------- + + function Is_In_Main_Unit (N : Node_Id) return Boolean is + Unum : constant Unit_Number_Type := Get_Source_Unit (N); + + Current_Unit : Node_Id; + + begin + if Unum = Main_Unit then + return True; + + -- If the current unit is a subunit then it is either the main unit + -- or is being compiled as part of the main unit. + + elsif Nkind (N) = N_Compilation_Unit then + return Nkind (Unit (N)) = N_Subunit; + end if; + + Current_Unit := Parent (N); + while Present (Current_Unit) + and then Nkind (Current_Unit) /= N_Compilation_Unit + loop + Current_Unit := Parent (Current_Unit); + end loop; + + -- The instantiation node is in the main unit, or else the current + -- node (perhaps as the result of nested instantiations) is in the + -- main unit, or in the declaration of the main unit, which in this + -- last case must be a body. + + return Unum = Main_Unit + or else Current_Unit = Cunit (Main_Unit) + or else Current_Unit = Library_Unit (Cunit (Main_Unit)) + or else (Present (Library_Unit (Current_Unit)) + and then Is_In_Main_Unit (Library_Unit (Current_Unit))); + end Is_In_Main_Unit; + + ---------------------------- + -- Load_Parent_Of_Generic -- + ---------------------------- + + procedure Load_Parent_Of_Generic (N : Node_Id; Spec : Node_Id) is + Comp_Unit : constant Node_Id := Cunit (Get_Source_Unit (Spec)); + True_Parent : Node_Id; + Inst_Node : Node_Id; + OK : Boolean; + Save_Style_Check : Boolean := Style_Check; + + begin + if not In_Same_Source_Unit (N, Spec) + or else Nkind (Unit (Comp_Unit)) = N_Package_Declaration + or else (Nkind (Unit (Comp_Unit)) = N_Package_Body + and then not Is_In_Main_Unit (Spec)) + then + -- Find body of parent of spec, and analyze it. A special case + -- arises when the parent is an instantiation, that is to say when + -- we are currently instantiating a nested generic. In that case, + -- there is no separate file for the body of the enclosing instance. + -- Instead, the enclosing body must be instantiated as if it were + -- a pending instantiation, in order to produce the body for the + -- nested generic we require now. Note that in that case the + -- generic may be defined in a package body, the instance defined + -- in the same package body, and the original enclosing body may not + -- be in the main unit. + + True_Parent := Parent (Spec); + Inst_Node := Empty; + + while Present (True_Parent) + and then Nkind (True_Parent) /= N_Compilation_Unit + loop + if Nkind (True_Parent) = N_Package_Declaration + and then + Nkind (Original_Node (True_Parent)) = N_Package_Instantiation + then + -- Parent is a compilation unit that is an instantiation. + -- Instantiation node has been replaced with package decl. + + Inst_Node := Original_Node (True_Parent); + exit; + + elsif Nkind (True_Parent) = N_Package_Declaration + and then Present (Generic_Parent (Specification (True_Parent))) + then + -- Parent is an instantiation within another specification. + -- Declaration for instance has been inserted before original + -- instantiation node. A direct link would be preferable? + + Inst_Node := Next (True_Parent); + + while Present (Inst_Node) + and then Nkind (Inst_Node) /= N_Package_Instantiation + loop + Next (Inst_Node); + end loop; + + -- If the instance appears within a generic, and the generic + -- unit is defined within a formal package of the enclosing + -- generic, there is no generic body available, and none + -- needed. A more precise test should be used ??? + + if No (Inst_Node) then + return; + end if; + + exit; + else + True_Parent := Parent (True_Parent); + end if; + end loop; + + if Present (Inst_Node) then + + if Nkind (Parent (True_Parent)) = N_Compilation_Unit then + + -- Instantiation node and declaration of instantiated package + -- were exchanged when only the declaration was needed. + -- Restore instantiation node before proceeding with body. + + Set_Unit (Parent (True_Parent), Inst_Node); + end if; + + -- Now complete instantiation of enclosing body, if it appears + -- in some other unit. If it appears in the current unit, the + -- body will have been instantiated already. + + if No (Corresponding_Body (Instance_Spec (Inst_Node))) then + Instantiate_Package_Body + (Pending_Body_Info'( + Inst_Node, True_Parent, Expander_Active, + Get_Code_Unit (Sloc (Inst_Node)))); + end if; + + else + Opt.Style_Check := False; + Load_Needed_Body (Comp_Unit, OK); + Opt.Style_Check := Save_Style_Check; + + if not OK + and then Unit_Requires_Body (Defining_Entity (Spec)) + then + declare + Bname : constant Unit_Name_Type := + Get_Body_Name (Get_Unit_Name (Unit (Comp_Unit))); + + begin + Error_Msg_Unit_1 := Bname; + Error_Msg_N ("this instantiation requires$!", N); + Error_Msg_Name_1 := + Get_File_Name (Bname, Subunit => False); + Error_Msg_N ("\but file{ was not found!", N); + raise Unrecoverable_Error; + end; + end if; + end if; + end if; + + -- If loading the parent of the generic caused an instantiation + -- circularity, we abandon compilation at this point, because + -- otherwise in some cases we get into trouble with infinite + -- recursions after this point. + + if Circularity_Detected then + raise Unrecoverable_Error; + end if; + + end Load_Parent_Of_Generic; + + ----------------------- + -- Move_Freeze_Nodes -- + ----------------------- + + procedure Move_Freeze_Nodes + (Out_Of : Entity_Id; + After : Node_Id; + L : List_Id) + is + Decl : Node_Id; + Next_Decl : Node_Id; + Next_Node : Node_Id := After; + Spec : Node_Id; + + function Is_Outer_Type (T : Entity_Id) return Boolean; + -- Check whether entity is declared in a scope external to that + -- of the generic unit. + + ------------------- + -- Is_Outer_Type -- + ------------------- + + function Is_Outer_Type (T : Entity_Id) return Boolean is + Scop : Entity_Id := Scope (T); + + begin + if Scope_Depth (Scop) < Scope_Depth (Out_Of) then + return True; + + else + while Scop /= Standard_Standard loop + + if Scop = Out_Of then + return False; + else + Scop := Scope (Scop); + end if; + end loop; + + return True; + end if; + end Is_Outer_Type; + + -- Start of processing for Move_Freeze_Nodes + + begin + if No (L) then + return; + end if; + + -- First remove the freeze nodes that may appear before all other + -- declarations. + + Decl := First (L); + while Present (Decl) + and then Nkind (Decl) = N_Freeze_Entity + and then Is_Outer_Type (Entity (Decl)) + loop + Decl := Remove_Head (L); + Insert_After (Next_Node, Decl); + Set_Analyzed (Decl, False); + Next_Node := Decl; + Decl := First (L); + end loop; + + -- Next scan the list of declarations and remove each freeze node that + -- appears ahead of the current node. + + while Present (Decl) loop + while Present (Next (Decl)) + and then Nkind (Next (Decl)) = N_Freeze_Entity + and then Is_Outer_Type (Entity (Next (Decl))) + loop + Next_Decl := Remove_Next (Decl); + Insert_After (Next_Node, Next_Decl); + Set_Analyzed (Next_Decl, False); + Next_Node := Next_Decl; + end loop; + + -- If the declaration is a nested package or concurrent type, then + -- recurse. Nested generic packages will have been processed from the + -- inside out. + + if Nkind (Decl) = N_Package_Declaration then + Spec := Specification (Decl); + + elsif Nkind (Decl) = N_Task_Type_Declaration then + Spec := Task_Definition (Decl); + + elsif Nkind (Decl) = N_Protected_Type_Declaration then + Spec := Protected_Definition (Decl); + + else + Spec := Empty; + end if; + + if Present (Spec) then + Move_Freeze_Nodes (Out_Of, Next_Node, + Visible_Declarations (Spec)); + Move_Freeze_Nodes (Out_Of, Next_Node, + Private_Declarations (Spec)); + end if; + + Next (Decl); + end loop; + end Move_Freeze_Nodes; + + ---------------- + -- Next_Assoc -- + ---------------- + + function Next_Assoc (E : Assoc_Ptr) return Assoc_Ptr is + begin + return Generic_Renamings.Table (E).Next_In_HTable; + end Next_Assoc; + + ------------------------ + -- Preanalyze_Actuals -- + ------------------------ + + procedure Pre_Analyze_Actuals (N : Node_Id) is + Assoc : Node_Id; + Act : Node_Id; + Errs : Int := Errors_Detected; + + begin + Assoc := First (Generic_Associations (N)); + + while Present (Assoc) loop + Act := Explicit_Generic_Actual_Parameter (Assoc); + + -- Within a nested instantiation, a defaulted actual is an + -- empty association, so nothing to analyze. If the actual for + -- a subprogram is an attribute, analyze prefix only, because + -- actual is not a complete attribute reference. + -- String literals may be operators, but at this point we do not + -- know whether the actual is a formal subprogram or a string. + + if No (Act) then + null; + + elsif Nkind (Act) = N_Attribute_Reference then + Analyze (Prefix (Act)); + + elsif Nkind (Act) = N_Explicit_Dereference then + Analyze (Prefix (Act)); + + elsif Nkind (Act) /= N_Operator_Symbol then + Analyze (Act); + end if; + + if Errs /= Errors_Detected then + Abandon_Instantiation (Act); + end if; + + Next (Assoc); + end loop; + end Pre_Analyze_Actuals; + + ------------------- + -- Remove_Parent -- + ------------------- + + procedure Remove_Parent (In_Body : Boolean := False) is + S : Entity_Id := Current_Scope; + E : Entity_Id; + P : Entity_Id; + Hidden : Elmt_Id; + + begin + -- After child instantiation is complete, remove from scope stack + -- the extra copy of the current scope, and then remove parent + -- instances. + + if not In_Body then + Pop_Scope; + + while Current_Scope /= S loop + P := Current_Scope; + End_Package_Scope (Current_Scope); + + if In_Open_Scopes (P) then + E := First_Entity (P); + + while Present (E) loop + Set_Is_Immediately_Visible (E, True); + Next_Entity (E); + end loop; + + elsif not In_Open_Scopes (Scope (P)) then + Set_Is_Immediately_Visible (P, False); + end if; + end loop; + + -- Reset visibility of entities in the enclosing scope. + + Set_Is_Hidden_Open_Scope (Current_Scope, False); + Hidden := First_Elmt (Hidden_Entities); + + while Present (Hidden) loop + Set_Is_Immediately_Visible (Node (Hidden), True); + Next_Elmt (Hidden); + end loop; + + else + -- Each body is analyzed separately, and there is no context + -- that needs preserving from one body instance to the next, + -- so remove all parent scopes that have been installed. + + while Present (S) loop + End_Package_Scope (S); + S := Current_Scope; + exit when S = Standard_Standard; + end loop; + end if; + + end Remove_Parent; + + ----------------- + -- Restore_Env -- + ----------------- + + procedure Restore_Env is + Saved : Instance_Env renames Instance_Envs.Table (Instance_Envs.Last); + + begin + Ada_83 := Saved.Ada_83; + + if No (Current_Instantiated_Parent.Act_Id) then + + -- Restore environment after subprogram inlining + + Restore_Private_Views (Empty); + end if; + + Current_Instantiated_Parent := Saved.Instantiated_Parent; + Exchanged_Views := Saved.Exchanged_Views; + Hidden_Entities := Saved.Hidden_Entities; + Current_Sem_Unit := Saved.Current_Sem_Unit; + + Instance_Envs.Decrement_Last; + end Restore_Env; + + --------------------------- + -- Restore_Private_Views -- + --------------------------- + + procedure Restore_Private_Views + (Pack_Id : Entity_Id; + Is_Package : Boolean := True) + is + M : Elmt_Id; + E : Entity_Id; + Typ : Entity_Id; + Dep_Elmt : Elmt_Id; + Dep_Typ : Node_Id; + + begin + M := First_Elmt (Exchanged_Views); + while Present (M) loop + Typ := Node (M); + + -- Subtypes of types whose views have been exchanged, and that + -- are defined within the instance, were not on the list of + -- Private_Dependents on entry to the instance, so they have to + -- be exchanged explicitly now, in order to remain consistent with + -- the view of the parent type. + + if Ekind (Typ) = E_Private_Type + or else Ekind (Typ) = E_Limited_Private_Type + or else Ekind (Typ) = E_Record_Type_With_Private + then + Dep_Elmt := First_Elmt (Private_Dependents (Typ)); + + while Present (Dep_Elmt) loop + Dep_Typ := Node (Dep_Elmt); + + if Scope (Dep_Typ) = Pack_Id + and then Present (Full_View (Dep_Typ)) + then + Replace_Elmt (Dep_Elmt, Full_View (Dep_Typ)); + Exchange_Declarations (Dep_Typ); + end if; + + Next_Elmt (Dep_Elmt); + end loop; + end if; + + Exchange_Declarations (Node (M)); + Next_Elmt (M); + end loop; + + if No (Pack_Id) then + return; + end if; + + -- Make the generic formal parameters private, and make the formal + -- types into subtypes of the actuals again. + + E := First_Entity (Pack_Id); + + while Present (E) loop + Set_Is_Hidden (E, True); + + if Is_Type (E) + and then Nkind (Parent (E)) = N_Subtype_Declaration + then + Set_Is_Generic_Actual_Type (E, False); + + -- An unusual case of aliasing: the actual may also be directly + -- visible in the generic, and be private there, while it is + -- fully visible in the context of the instance. The internal + -- subtype is private in the instance, but has full visibility + -- like its parent in the enclosing scope. This enforces the + -- invariant that the privacy status of all private dependents of + -- a type coincide with that of the parent type. This can only + -- happen when a generic child unit is instantiated within a + -- sibling. + + if Is_Private_Type (E) + and then not Is_Private_Type (Etype (E)) + then + Exchange_Declarations (E); + end if; + + elsif Ekind (E) = E_Package then + + -- The end of the renaming list is the renaming of the generic + -- package itself. If the instance is a subprogram, all entities + -- in the corresponding package are renamings. If this entity is + -- a formal package, make its own formals private as well. The + -- actual in this case is itself the renaming of an instantation. + -- If the entity is not a package renaming, it is the entity + -- created to validate formal package actuals: ignore. + + -- If the actual is itself a formal package for the enclosing + -- generic, or the actual for such a formal package, it remains + -- visible after the current instance, and therefore nothing + -- needs to be done either, except to keep it accessible. + + if Is_Package + and then Renamed_Object (E) = Pack_Id + then + exit; + + elsif Nkind (Parent (E)) /= N_Package_Renaming_Declaration then + null; + + elsif Denotes_Formal_Package (Renamed_Object (E)) then + Set_Is_Hidden (E, False); + + else + declare + Act_P : Entity_Id := Renamed_Object (E); + Id : Entity_Id := First_Entity (Act_P); + + begin + while Present (Id) + and then Id /= First_Private_Entity (Act_P) + loop + Set_Is_Hidden (Id, True); + Set_Is_Potentially_Use_Visible (Id, In_Use (Act_P)); + exit when Ekind (Id) = E_Package + and then Renamed_Object (Id) = Act_P; + + Next_Entity (Id); + end loop; + end; + null; + end if; + end if; + + Next_Entity (E); + end loop; + end Restore_Private_Views; + + -------------- + -- Save_Env -- + -------------- + + procedure Save_Env + (Gen_Unit : Entity_Id; + Act_Unit : Entity_Id) + is + Saved : Instance_Env; + + begin + Saved.Ada_83 := Ada_83; + Saved.Instantiated_Parent := Current_Instantiated_Parent; + Saved.Exchanged_Views := Exchanged_Views; + Saved.Hidden_Entities := Hidden_Entities; + Saved.Current_Sem_Unit := Current_Sem_Unit; + Instance_Envs.Increment_Last; + Instance_Envs.Table (Instance_Envs.Last) := Saved; + + -- Regardless of the current mode, predefined units are analyzed in + -- Ada95 mode, and Ada83 checks don't apply. + + if Is_Internal_File_Name + (Fname => Unit_File_Name (Get_Source_Unit (Gen_Unit)), + Renamings_Included => True) then + Ada_83 := False; + end if; + + Current_Instantiated_Parent := (Gen_Unit, Act_Unit, Assoc_Null); + Exchanged_Views := New_Elmt_List; + Hidden_Entities := New_Elmt_List; + end Save_Env; + + ---------------------------- + -- Save_Global_References -- + ---------------------------- + + procedure Save_Global_References (N : Node_Id) is + Gen_Scope : Entity_Id; + E : Entity_Id; + N2 : Node_Id; + + function Is_Global (E : Entity_Id) return Boolean; + -- Check whether entity is defined outside of generic unit. + -- Examine the scope of an entity, and the scope of the scope, + -- etc, until we find either Standard, in which case the entity + -- is global, or the generic unit itself, which indicates that + -- the entity is local. If the entity is the generic unit itself, + -- as in the case of a recursive call, or the enclosing generic unit, + -- if different from the current scope, then it is local as well, + -- because it will be replaced at the point of instantiation. On + -- the other hand, if it is a reference to a child unit of a common + -- ancestor, which appears in an instantiation, it is global because + -- it is used to denote a specific compilation unit at the time the + -- instantiations will be analyzed. + + procedure Reset_Entity (N : Node_Id); + -- Save semantic information on global entity, so that it is not + -- resolved again at instantiation time. + + procedure Save_Global_Defaults (N1, N2 : Node_Id); + -- Default actuals in nested instances must be handled specially + -- because there is no link to them from the original tree. When an + -- actual subprogram is given by a default, we add an explicit generic + -- association for it in the instantiation node. When we save the + -- global references on the name of the instance, we recover the list + -- of generic associations, and add an explicit one to the original + -- generic tree, through which a global actual can be preserved. + -- Similarly, if a child unit is instantiated within a sibling, in the + -- context of the parent, we must preserve the identifier of the parent + -- so that it can be properly resolved in a subsequent instantiation. + + procedure Save_Global_Descendant (D : Union_Id); + -- Apply Save_Global_References recursively to the descendents of + -- current node. + + procedure Save_References (N : Node_Id); + -- This is the recursive procedure that does the work, once the + -- enclosing generic scope has been established. + + --------------- + -- Is_Global -- + --------------- + + function Is_Global (E : Entity_Id) return Boolean is + Se : Entity_Id := Scope (E); + + function Is_Instance_Node (Decl : Node_Id) return Boolean; + -- Determine whether the parent node of a reference to a child unit + -- denotes an instantiation or a formal package, in which case the + -- reference to the child unit is global, even if it appears within + -- the current scope (e.g. when the instance appears within the body + -- of an ancestor). + + function Is_Instance_Node (Decl : Node_Id) return Boolean is + begin + return (Nkind (Decl) in N_Generic_Instantiation + or else + Nkind (Original_Node (Decl)) = N_Formal_Package_Declaration); + end Is_Instance_Node; + + -- Start of processing for Is_Global + + begin + if E = Gen_Scope then + return False; + + elsif E = Standard_Standard then + return True; + + elsif Is_Child_Unit (E) + and then (Is_Instance_Node (Parent (N2)) + or else (Nkind (Parent (N2)) = N_Expanded_Name + and then N2 = Selector_Name (Parent (N2)) + and then Is_Instance_Node (Parent (Parent (N2))))) + then + return True; + + else + while Se /= Gen_Scope loop + if Se = Standard_Standard then + return True; + else + Se := Scope (Se); + end if; + end loop; + + return False; + end if; + end Is_Global; + + ------------------ + -- Reset_Entity -- + ------------------ + + procedure Reset_Entity (N : Node_Id) is + + procedure Set_Global_Type (N : Node_Id; N2 : Node_Id); + -- The type of N2 is global to the generic unit. Save the + -- type in the generic node. + + procedure Set_Global_Type (N : Node_Id; N2 : Node_Id) is + Typ : constant Entity_Id := Etype (N2); + + begin + Set_Etype (N, Typ); + + if Entity (N) /= N2 + and then Has_Private_View (Entity (N)) + then + -- If the entity of N is not the associated node, this is + -- a nested generic and it has an associated node as well, + -- whose type is already the full view (see below). Indicate + -- that the original node has a private view. + + Set_Has_Private_View (N); + end if; + + -- If not a private type, nothing else to do + + if not Is_Private_Type (Typ) then + if Is_Array_Type (Typ) + and then Is_Private_Type (Component_Type (Typ)) + then + Set_Has_Private_View (N); + end if; + + -- If it is a derivation of a private type in a context where + -- no full view is needed, nothing to do either. + + elsif No (Full_View (Typ)) and then Typ /= Etype (Typ) then + null; + + -- Otherwise mark the type for flipping and use the full_view + -- when available. + + else + Set_Has_Private_View (N); + + if Present (Full_View (Typ)) then + Set_Etype (N2, Full_View (Typ)); + end if; + end if; + end Set_Global_Type; + + -- Start of processing for Reset_Entity + + begin + N2 := Associated_Node (N); + E := Entity (N2); + + if Present (E) then + if Is_Global (E) then + Set_Global_Type (N, N2); + + elsif Nkind (N) = N_Op_Concat + and then Is_Generic_Type (Etype (N2)) + and then + (Base_Type (Etype (Right_Opnd (N2))) = Etype (N2) + or else Base_Type (Etype (Left_Opnd (N2))) = Etype (N2)) + and then Is_Intrinsic_Subprogram (E) + then + null; + + else + -- Entity is local. Mark generic node as unresolved. + -- Note that now it does not have an entity. + + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + if (Nkind (Parent (N)) = N_Package_Instantiation + or else Nkind (Parent (N)) = N_Function_Instantiation + or else Nkind (Parent (N)) = N_Procedure_Instantiation) + and then N = Name (Parent (N)) + then + Save_Global_Defaults (Parent (N), Parent (N2)); + end if; + + elsif Nkind (Parent (N)) = N_Selected_Component + and then Nkind (Parent (N2)) = N_Expanded_Name + then + + if Is_Global (Entity (Parent (N2))) then + Change_Selected_Component_To_Expanded_Name (Parent (N)); + Set_Associated_Node (Parent (N), Parent (N2)); + Set_Global_Type (Parent (N), Parent (N2)); + + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + + -- If this is a reference to the current generic entity, + -- replace it with a simple name. This is to avoid anomalies + -- when the enclosing scope is also a generic unit, in which + -- case the selected component will not resolve to the current + -- unit within an instance of the outer one. Ditto if the + -- entity is an enclosing scope, e.g. a parent unit. + + elsif In_Open_Scopes (Entity (Parent (N2))) + and then not Is_Generic_Unit (Entity (Prefix (Parent (N2)))) + then + Rewrite (Parent (N), + Make_Identifier (Sloc (N), + Chars => Chars (Selector_Name (Parent (N2))))); + end if; + + if (Nkind (Parent (Parent (N))) = N_Package_Instantiation + or else Nkind (Parent (Parent (N))) + = N_Function_Instantiation + or else Nkind (Parent (Parent (N))) + = N_Procedure_Instantiation) + and then Parent (N) = Name (Parent (Parent (N))) + then + Save_Global_Defaults + (Parent (Parent (N)), Parent (Parent ((N2)))); + end if; + + -- A selected component may denote a static constant that has + -- been folded. Make the same replacement in original tree. + + elsif Nkind (Parent (N)) = N_Selected_Component + and then (Nkind (Parent (N2)) = N_Integer_Literal + or else Nkind (Parent (N2)) = N_Real_Literal) + then + Rewrite (Parent (N), + New_Copy (Parent (N2))); + Set_Analyzed (Parent (N), False); + + -- a selected component may be transformed into a parameterless + -- function call. If the called entity is global, rewrite the + -- node appropriately, i.e. as an extended name for the global + -- entity. + + elsif Nkind (Parent (N)) = N_Selected_Component + and then Nkind (Parent (N2)) = N_Function_Call + and then Is_Global (Entity (Name (Parent (N2)))) + then + Change_Selected_Component_To_Expanded_Name (Parent (N)); + Set_Associated_Node (Parent (N), Name (Parent (N2))); + Set_Global_Type (Parent (N), Name (Parent (N2))); + + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + + else + -- Entity is local. Reset in generic unit, so that node + -- is resolved anew at the point of instantiation. + + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + end Reset_Entity; + + -------------------------- + -- Save_Global_Defaults -- + -------------------------- + + procedure Save_Global_Defaults (N1, N2 : Node_Id) is + Loc : constant Source_Ptr := Sloc (N1); + Assoc1 : List_Id := Generic_Associations (N1); + Assoc2 : List_Id := Generic_Associations (N2); + Act1 : Node_Id; + Act2 : Node_Id; + Def : Node_Id; + Gen_Id : Entity_Id := Entity (Name (N2)); + Ndec : Node_Id; + Subp : Entity_Id; + Actual : Entity_Id; + + begin + if Present (Assoc1) then + Act1 := First (Assoc1); + else + Act1 := Empty; + Set_Generic_Associations (N1, New_List); + Assoc1 := Generic_Associations (N1); + end if; + + if Present (Assoc2) then + Act2 := First (Assoc2); + else + return; + end if; + + while Present (Act1) and then Present (Act2) loop + Next (Act1); + Next (Act2); + end loop; + + -- Find the associations added for default suprograms. + + if Present (Act2) then + while Nkind (Act2) /= N_Generic_Association + or else No (Entity (Selector_Name (Act2))) + or else not Is_Overloadable (Entity (Selector_Name (Act2))) + loop + Next (Act2); + end loop; + + -- Add a similar association if the default is global. The + -- renaming declaration for the actual has been analyzed, and + -- its alias is the program it renames. Link the actual in the + -- original generic tree with the node in the analyzed tree. + + while Present (Act2) loop + Subp := Entity (Selector_Name (Act2)); + Def := Explicit_Generic_Actual_Parameter (Act2); + + -- Following test is defence against rubbish errors + + if No (Alias (Subp)) then + return; + end if; + + -- Retrieve the resolved actual from the renaming declaration + -- created for the instantiated formal. + + Actual := Entity (Name (Parent (Parent (Subp)))); + Set_Entity (Def, Actual); + Set_Etype (Def, Etype (Actual)); + + if Is_Global (Actual) then + Ndec := + Make_Generic_Association (Loc, + Selector_Name => New_Occurrence_Of (Subp, Loc), + Explicit_Generic_Actual_Parameter => + New_Occurrence_Of (Actual, Loc)); + + Set_Associated_Node + (Explicit_Generic_Actual_Parameter (Ndec), Def); + + Append (Ndec, Assoc1); + + -- If there are other defaults, add a dummy association + -- in case there are other defaulted formals with the same + -- name. + + elsif Present (Next (Act2)) then + Ndec := + Make_Generic_Association (Loc, + Selector_Name => New_Occurrence_Of (Subp, Loc), + Explicit_Generic_Actual_Parameter => Empty); + + Append (Ndec, Assoc1); + end if; + + Next (Act2); + end loop; + end if; + + if Nkind (Name (N1)) = N_Identifier + and then Is_Child_Unit (Gen_Id) + and then Is_Global (Gen_Id) + and then Is_Generic_Unit (Scope (Gen_Id)) + and then In_Open_Scopes (Scope (Gen_Id)) + then + -- This is an instantiation of a child unit within a sibling, + -- so that the generic parent is in scope. An eventual instance + -- must occur within the scope of an instance of the parent. + -- Make name in instance into an expanded name, to preserve the + -- identifier of the parent, so it can be resolved subsequently. + + Rewrite (Name (N2), + Make_Expanded_Name (Loc, + Chars => Chars (Gen_Id), + Prefix => New_Occurrence_Of (Scope (Gen_Id), Loc), + Selector_Name => New_Occurrence_Of (Gen_Id, Loc))); + Set_Entity (Name (N2), Gen_Id); + + Rewrite (Name (N1), + Make_Expanded_Name (Loc, + Chars => Chars (Gen_Id), + Prefix => New_Occurrence_Of (Scope (Gen_Id), Loc), + Selector_Name => New_Occurrence_Of (Gen_Id, Loc))); + + Set_Associated_Node (Name (N1), Name (N2)); + Set_Associated_Node (Prefix (Name (N1)), Empty); + Set_Associated_Node + (Selector_Name (Name (N1)), Selector_Name (Name (N2))); + Set_Etype (Name (N1), Etype (Gen_Id)); + end if; + + end Save_Global_Defaults; + + ---------------------------- + -- Save_Global_Descendant -- + ---------------------------- + + procedure Save_Global_Descendant (D : Union_Id) is + N1 : Node_Id; + + begin + if D in Node_Range then + if D = Union_Id (Empty) then + null; + + elsif Nkind (Node_Id (D)) /= N_Compilation_Unit then + Save_References (Node_Id (D)); + end if; + + elsif D in List_Range then + if D = Union_Id (No_List) + or else Is_Empty_List (List_Id (D)) + then + null; + + else + N1 := First (List_Id (D)); + while Present (N1) loop + Save_References (N1); + Next (N1); + end loop; + end if; + + -- Element list or other non-node field, nothing to do + + else + null; + end if; + end Save_Global_Descendant; + + --------------------- + -- Save_References -- + --------------------- + + -- This is the recursive procedure that does the work, once the + -- enclosing generic scope has been established. We have to treat + -- specially a number of node rewritings that are required by semantic + -- processing and which change the kind of nodes in the generic copy: + -- typically constant-folding, replacing an operator node by a string + -- literal, or a selected component by an expanded name. In each of + -- those cases, the transformation is propagated to the generic unit. + + procedure Save_References (N : Node_Id) is + begin + if N = Empty then + null; + + elsif (Nkind (N) = N_Character_Literal + or else Nkind (N) = N_Operator_Symbol) + then + if Nkind (N) = Nkind (Associated_Node (N)) then + Reset_Entity (N); + + elsif Nkind (N) = N_Operator_Symbol + and then Nkind (Associated_Node (N)) = N_String_Literal + then + Change_Operator_Symbol_To_String_Literal (N); + end if; + + elsif Nkind (N) in N_Op then + + if Nkind (N) = Nkind (Associated_Node (N)) then + + if Nkind (N) = N_Op_Concat then + Set_Is_Component_Left_Opnd (N, + Is_Component_Left_Opnd (Associated_Node (N))); + + Set_Is_Component_Right_Opnd (N, + Is_Component_Right_Opnd (Associated_Node (N))); + end if; + + Reset_Entity (N); + else + -- Node may be transformed into call to a user-defined operator + + N2 := Associated_Node (N); + + if Nkind (N2) = N_Function_Call then + E := Entity (Name (N2)); + + if Present (E) + and then Is_Global (E) + then + Set_Etype (N, Etype (N2)); + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + elsif Nkind (N2) = N_Integer_Literal + or else Nkind (N2) = N_Real_Literal + or else Nkind (N2) = N_String_Literal + or else (Nkind (N2) = N_Identifier + and then + Ekind (Entity (N2)) = E_Enumeration_Literal) + then + -- Operation was constant-folded, perform the same + -- replacement in generic. + + -- Note: we do a Replace here rather than a Rewrite, + -- which is a definite violation of the standard rules + -- with regard to retrievability of the original tree, + -- and likely ASIS bugs or at least irregularities are + -- caused by this choice. + + -- The reason we do this is that the appropriate original + -- nodes are never constructed (we don't go applying the + -- generic instantiation to rewritten nodes in general). + -- We could try to create an appropriate copy but it would + -- be hard work and does not seem worth while, because + -- the original expression is accessible in the generic, + -- and ASIS rules for traversing instances are fuzzy. + + Replace (N, New_Copy (N2)); + Set_Analyzed (N, False); + end if; + end if; + + -- Complete the check on operands. + + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + + elsif Nkind (N) = N_Identifier then + if Nkind (N) = Nkind (Associated_Node (N)) then + + -- If this is a discriminant reference, always save it. + -- It is used in the instance to find the corresponding + -- discriminant positionally rather than by name. + + Set_Original_Discriminant + (N, Original_Discriminant (Associated_Node (N))); + Reset_Entity (N); + + else + N2 := Associated_Node (N); + + if Nkind (N2) = N_Function_Call then + E := Entity (Name (N2)); + + -- Name resolves to a call to parameterless function. + -- If original entity is global, mark node as resolved. + + if Present (E) + and then Is_Global (E) + then + Set_Etype (N, Etype (N2)); + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + elsif + Nkind (N2) = N_Integer_Literal or else + Nkind (N2) = N_Real_Literal or else + Nkind (N2) = N_String_Literal + then + -- Name resolves to named number that is constant-folded, + -- or to string literal from concatenation. + -- Perform the same replacement in generic. + + Rewrite (N, New_Copy (N2)); + Set_Analyzed (N, False); + + elsif Nkind (N2) = N_Explicit_Dereference then + + -- An identifier is rewritten as a dereference if it is + -- the prefix in a selected component, and it denotes an + -- access to a composite type, or a parameterless function + -- call that returns an access type. + + -- Check whether corresponding entity in prefix is global. + + if Is_Entity_Name (Prefix (N2)) + and then Present (Entity (Prefix (N2))) + and then Is_Global (Entity (Prefix (N2))) + then + Rewrite (N, + Make_Explicit_Dereference (Sloc (N), + Prefix => Make_Identifier (Sloc (N), + Chars => Chars (N)))); + Set_Associated_Node (Prefix (N), Prefix (N2)); + + elsif Nkind (Prefix (N2)) = N_Function_Call + and then Is_Global (Entity (Name (Prefix (N2)))) + then + Rewrite (N, + Make_Explicit_Dereference (Sloc (N), + Prefix => Make_Function_Call (Sloc (N), + Name => + Make_Identifier (Sloc (N), + Chars => Chars (N))))); + + Set_Associated_Node + (Name (Prefix (N)), Name (Prefix (N2))); + + else + Set_Associated_Node (N, Empty); + Set_Etype (N, Empty); + end if; + + -- The subtype mark of a nominally unconstrained object + -- is rewritten as a subtype indication using the bounds + -- of the expression. Recover the original subtype mark. + + elsif Nkind (N2) = N_Subtype_Indication + and then Is_Entity_Name (Original_Node (N2)) + then + Set_Associated_Node (N, Original_Node (N2)); + Reset_Entity (N); + + else + null; + end if; + end if; + + elsif Nkind (N) in N_Entity then + null; + + elsif Nkind (N) = N_Aggregate + or else Nkind (N) = N_Extension_Aggregate + then + N2 := Associated_Node (N); + if No (N2) + or else No (Etype (N2)) + or else not Is_Global (Etype (N2)) + then + Set_Associated_Node (N, Empty); + end if; + + Save_Global_Descendant (Field1 (N)); + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + Save_Global_Descendant (Field5 (N)); + + else + Save_Global_Descendant (Field1 (N)); + Save_Global_Descendant (Field2 (N)); + Save_Global_Descendant (Field3 (N)); + Save_Global_Descendant (Field4 (N)); + Save_Global_Descendant (Field5 (N)); + + end if; + end Save_References; + + -- Start of processing for Save_Global_References + + begin + Gen_Scope := Current_Scope; + + -- If the generic unit is a child unit, references to entities in + -- the parent are treated as local, because they will be resolved + -- anew in the context of the instance of the parent. + + while Is_Child_Unit (Gen_Scope) + and then Ekind (Scope (Gen_Scope)) = E_Generic_Package + loop + Gen_Scope := Scope (Gen_Scope); + end loop; + + Save_References (N); + end Save_Global_References; + + ------------------------- + -- Set_Associated_Node -- + ------------------------- + + -- Note from RBKD: the uncommented use of Set_Node4 below is ugly ??? + + procedure Set_Associated_Node + (Gen_Node : Node_Id; + Copy_Node : Node_Id) + is + begin + Set_Node4 (Gen_Node, Copy_Node); + end Set_Associated_Node; + + --------------------- + -- Set_Copied_Sloc -- + --------------------- + + procedure Set_Copied_Sloc (N : Node_Id; E : Entity_Id) is + begin + Create_Instantiation_Source (N, E, S_Adjustment); + end Set_Copied_Sloc; + + --------------------- + -- Set_Instance_Of -- + --------------------- + + procedure Set_Instance_Of (A : Entity_Id; B : Entity_Id) is + begin + Generic_Renamings.Table (Generic_Renamings.Last) := (A, B, Assoc_Null); + Generic_Renamings_HTable.Set (Generic_Renamings.Last); + Generic_Renamings.Increment_Last; + end Set_Instance_Of; + + -------------------- + -- Set_Next_Assoc -- + -------------------- + + procedure Set_Next_Assoc (E : Assoc_Ptr; Next : Assoc_Ptr) is + begin + Generic_Renamings.Table (E).Next_In_HTable := Next; + end Set_Next_Assoc; + + ------------------- + -- Start_Generic -- + ------------------- + + procedure Start_Generic is + begin + -- ??? I am sure more things could be factored out in this + -- routine. Should probably be done at a later stage. + + Generic_Flags.Increment_Last; + Generic_Flags.Table (Generic_Flags.Last) := Inside_A_Generic; + Inside_A_Generic := True; + + Expander_Mode_Save_And_Set (False); + end Start_Generic; + + ----------------- + -- Switch_View -- + ----------------- + + procedure Switch_View (T : Entity_Id) is + Priv_Elmt : Elmt_Id := No_Elmt; + Priv_Sub : Entity_Id; + BT : Entity_Id := Base_Type (T); + + begin + -- T may be private but its base type may have been exchanged through + -- some other occurrence, in which case there is nothing to switch. + + if not Is_Private_Type (BT) then + return; + end if; + + Priv_Elmt := First_Elmt (Private_Dependents (BT)); + + if Present (Full_View (BT)) then + Append_Elmt (Full_View (BT), Exchanged_Views); + Exchange_Declarations (BT); + end if; + + while Present (Priv_Elmt) loop + Priv_Sub := (Node (Priv_Elmt)); + + -- We avoid flipping the subtype if the Etype of its full + -- view is private because this would result in a malformed + -- subtype. This occurs when the Etype of the subtype full + -- view is the full view of the base type (and since the + -- base types were just switched, the subtype is pointing + -- to the wrong view). This is currently the case for + -- tagged record types, access types (maybe more?) and + -- needs to be resolved. ??? + + if Present (Full_View (Priv_Sub)) + and then not Is_Private_Type (Etype (Full_View (Priv_Sub))) + then + Append_Elmt (Full_View (Priv_Sub), Exchanged_Views); + Exchange_Declarations (Priv_Sub); + end if; + + Next_Elmt (Priv_Elmt); + end loop; + end Switch_View; + + ----------------------------- + -- Valid_Default_Attribute -- + ----------------------------- + + procedure Valid_Default_Attribute (Nam : Entity_Id; Def : Node_Id) is + Attr_Id : constant Attribute_Id := + Get_Attribute_Id (Attribute_Name (Def)); + F : Entity_Id; + Num_F : Int; + T : Entity_Id := Entity (Prefix (Def)); + OK : Boolean; + Is_Fun : constant Boolean := (Ekind (Nam) = E_Function); + + begin + if No (T) + or else T = Any_Id + then + return; + end if; + + Num_F := 0; + F := First_Formal (Nam); + while Present (F) loop + Num_F := Num_F + 1; + Next_Formal (F); + end loop; + + case Attr_Id is + when Attribute_Adjacent | Attribute_Ceiling | Attribute_Copy_Sign | + Attribute_Floor | Attribute_Fraction | Attribute_Machine | + Attribute_Model | Attribute_Remainder | Attribute_Rounding | + Attribute_Unbiased_Rounding => + OK := (Is_Fun and then Num_F = 1 and then Is_Floating_Point_Type (T)); + + when Attribute_Image | Attribute_Pred | Attribute_Succ | + Attribute_Value | Attribute_Wide_Image | + Attribute_Wide_Value => + OK := (Is_Fun and then Num_F = 1 and then Is_Scalar_Type (T)); + + when Attribute_Max | Attribute_Min => + OK := (Is_Fun and then Num_F = 2 and then Is_Scalar_Type (T)); + + when Attribute_Input => + OK := (Is_Fun and then Num_F = 1); + + when Attribute_Output | Attribute_Read | Attribute_Write => + OK := (not Is_Fun and then Num_F = 2); + + when others => OK := False; + end case; + + if not OK then + Error_Msg_N ("attribute reference has wrong profile for subprogram", + Def); + end if; + end Valid_Default_Attribute; + +end Sem_Ch12; |