diff options
Diffstat (limited to 'gcc/ada/sem_util.ads')
| -rw-r--r-- | gcc/ada/sem_util.ads | 189 |
1 files changed, 140 insertions, 49 deletions
diff --git a/gcc/ada/sem_util.ads b/gcc/ada/sem_util.ads index f0f518c104c..925b5c4d468 100644 --- a/gcc/ada/sem_util.ads +++ b/gcc/ada/sem_util.ads @@ -6,7 +6,7 @@ -- -- -- S p e c -- -- -- --- Copyright (C) 1992-2002, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2003, 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- -- @@ -50,7 +50,8 @@ package Sem_Util is Ent : Entity_Id := Empty; Typ : Entity_Id := Empty; Loc : Source_Ptr := No_Location; - Rep : Boolean := True); + Rep : Boolean := True; + Warn : Boolean := False); -- N is a subexpression which will raise constraint error when evaluated -- at runtime. Msg is a message that explains the reason for raising the -- exception. The last character is ? if the message is always a warning, @@ -67,27 +68,27 @@ package Sem_Util is -- normally references Etype (N), unless the Ent argument is given -- explicitly, in which case it is used instead. The type of the raise -- node that is built is normally Etype (N), but if the Typ parameter - -- is present, this is used instead. + -- is present, this is used instead. Warn is normally False. If it is + -- True then the message is treated as a warning even though it does + -- not end with a ? (this is used when the caller wants to parametrize + -- whether an error or warning is given. function Build_Actual_Subtype - (T : Entity_Id; - N : Node_Or_Entity_Id) - return Node_Id; + (T : Entity_Id; + N : Node_Or_Entity_Id) return Node_Id; -- Build an anonymous subtype for an entity or expression, using the -- bounds of the entity or the discriminants of the enclosing record. -- T is the type for which the actual subtype is required, and N is either -- a defining identifier, or any subexpression. function Build_Actual_Subtype_Of_Component - (T : Entity_Id; - N : Node_Id) - return Node_Id; + (T : Entity_Id; + N : Node_Id) return Node_Id; -- Determine whether a selected component has a type that depends on -- discriminants, and build actual subtype for it if so. function Build_Discriminal_Subtype_Of_Component - (T : Entity_Id) - return Node_Id; + (T : Entity_Id) return Node_Id; -- Determine whether a record component has a type that depends on -- discriminants, and build actual subtype for it if so. @@ -128,11 +129,13 @@ package Sem_Util is (N : Node_Id; Msg : String; Ent : Entity_Id := Empty; - Loc : Source_Ptr := No_Location) - return Node_Id; + Loc : Source_Ptr := No_Location; + Warn : Boolean := False) return Node_Id; -- Subsidiary to Apply_Compile_Time_Constraint_Error and Checks routines. -- Does not modify any nodes, but generates a warning (or error) message. - -- For convenience, the function always returns its first argument. + -- For convenience, the function always returns its first argument. The + -- message is a warning if the message ends with ?, or we are operating + -- in Ada 83 mode, or if the Warn parameter is set to True. procedure Conditional_Delay (New_Ent, Old_Ent : Entity_Id); -- Sets the Has_Delayed_Freeze flag of New if the Delayed_Freeze flag @@ -164,10 +167,14 @@ package Sem_Util is -- then the defining entity is obtained from the defining unit name -- ignoring any child unit prefixes. - function Denotes_Discriminant (N : Node_Id) return Boolean; - -- Returns True if node N is an N_Identifier node for a discriminant. - -- Returns False for any other kind of node, or for an N_Identifier - -- node that does not denote a discriminant. + function Denotes_Discriminant + (N : Node_Id; + Check_Protected : Boolean := False) return Boolean; + -- Returns True if node N is an Entity_Name node for a discriminant. + -- If the flag Check_Protected is true, function also returns true + -- when N denotes the discriminal of the discriminant of a protected + -- type. This is necessary to disable some optimizations on private + -- components of protected types. function Depends_On_Discriminant (N : Node_Id) return Boolean; -- Returns True if N denotes a discriminant or if N is a range, a subtype @@ -176,15 +183,13 @@ package Sem_Util is function Designate_Same_Unit (Name1 : Node_Id; - Name2 : Node_Id) - return Boolean; + Name2 : Node_Id) return Boolean; -- Return true if Name1 and Name2 designate the same unit name; -- each of these names is supposed to be a selected component name, -- an expanded name, a defining program unit name or an identifier function Enclosing_Generic_Body - (E : Entity_Id) - return Node_Id; + (E : Entity_Id) return Node_Id; -- Returns the Node_Id associated with the innermost enclosing -- generic body, if any. If none, then returns Empty. @@ -212,10 +217,15 @@ package Sem_Util is -- Note: Enter_Name is not used for overloadable entities, instead -- these are entered using Sem_Ch6.Enter_Overloadable_Entity. + procedure Explain_Limited_Type (T : Entity_Id; N : Node_Id); + -- This procedure is called after issuing a message complaining + -- about an inappropriate use of limited type T. If useful, it + -- adds additional continuation lines to the message explaining + -- why type T is limited. Messages are placed at node N. + function Find_Corresponding_Discriminant (Id : Node_Id; - Typ : Entity_Id) - return Entity_Id; + Typ : Entity_Id) return Entity_Id; -- Because discriminants may have different names in a generic unit -- and in an instance, they are resolved positionally when possible. -- A reference to a discriminant carries the discriminant that it @@ -238,6 +248,11 @@ package Sem_Util is -- Generates the string literal corresponding to the E's full qualified -- name in upper case. An ASCII.NUL is appended as the last character + function Find_Static_Alternative (N : Node_Id) return Node_Id; + -- N is a case statement whose expression is a compile-time value. + -- Determine the alternative chosen, so that the code of non-selected + -- alternatives, and the warnings that may apply to them, are removed. + procedure Gather_Components (Typ : Entity_Id; Comp_List : Node_Id; @@ -310,10 +325,9 @@ package Sem_Util is -- may be set to Error if there was an earlier error in the range. function Get_Enum_Lit_From_Pos - (T : Entity_Id; - Pos : Uint; - Loc : Source_Ptr) - return Entity_Id; + (T : Entity_Id; + Pos : Uint; + Loc : Source_Ptr) return Entity_Id; -- This function obtains the E_Enumeration_Literal entity for the -- specified value from the enumneration type or subtype T. The -- second argument is the Pos value, which is assumed to be in range. @@ -370,6 +384,9 @@ package Sem_Util is -- Returns True if current scope is within the visible part of a package -- instance, where several additional semantic checks apply. + function In_Package_Body return Boolean; + -- Returns True if current scope is within a package body + function In_Subprogram_Or_Concurrent_Unit return Boolean; -- Determines if the current scope is within a subprogram compilation -- unit (inside a subprogram declaration, subprogram body, or generic @@ -382,6 +399,12 @@ package Sem_Util is -- package specification. The package must be on the scope stack, and the -- corresponding private part must not. + procedure Insert_Explicit_Dereference (N : Node_Id); + -- In a context that requires a composite or subprogram type and + -- where a prefix is an access type, rewrite the access type node + -- N (which is the prefix, e.g. of an indexed component) as an + -- explicit dereference. + function Is_AAMP_Float (E : Entity_Id) return Boolean; -- Defined for all type entities. Returns True only for the base type -- of float types with AAMP format. The particular format is determined @@ -391,15 +414,6 @@ package Sem_Util is -- the dependency of Einfo on Targparm which would be required for a -- synthesized attribute. - function Is_Dependent_Component_Of_Mutable_Object - (Object : Node_Id) - return Boolean; - -- Returns True if Object is the name of a subcomponent that - -- depends on discriminants of a variable whose nominal subtype - -- is unconstrained and not indefinite, and the variable is - -- not aliased. Otherwise returns False. The nodes passed - -- to this function are assumed to denote objects. - function Is_Actual_Parameter (N : Node_Id) return Boolean; -- Determines if N is an actual parameter in a subprogram call. @@ -411,6 +425,20 @@ package Sem_Util is -- Determines if the given node denotes an atomic object in the sense -- of the legality checks described in RM C.6(12). + function Is_Dependent_Component_Of_Mutable_Object + (Object : Node_Id) return Boolean; + -- Returns True if Object is the name of a subcomponent that + -- depends on discriminants of a variable whose nominal subtype + -- is unconstrained and not indefinite, and the variable is + -- not aliased. Otherwise returns False. The nodes passed + -- to this function are assumed to denote objects. + + function Is_Dereferenced (N : Node_Id) return Boolean; + -- N is a subexpression node of an access type. This function returns + -- true if N appears as the prefix of a node that does a dereference + -- of the access value (selected/indexed component, explicit dereference + -- or a slice), and false otherwise. + function Is_False (U : Uint) return Boolean; -- The argument is a Uint value which is the Boolean'Pos value of a -- Boolean operand (i.e. is either 0 for False, or 1 for True). This @@ -424,12 +452,25 @@ package Sem_Util is -- Typ is a type entity. This function returns true if this type is -- fully initialized, meaning that an object of the type is fully -- initialized. Note that initialization resulting from the use of - -- pragma Normalized_Scalars does not count. + -- pragma Normalized_Scalars does not count. Note that this is only + -- used for the purpose of issuing warnings for objects that are + -- potentially referenced uninitialized. This means that the result + -- returned is not crucial, but probably should err on the side of + -- thinking things are fully initialized if it does not know. function Is_Inherited_Operation (E : Entity_Id) return Boolean; -- E is a subprogram. Return True is E is an implicit operation inherited -- by a derived type declarations. + function Is_Lvalue (N : Node_Id) return Boolean; + -- Determines if N could be an lvalue (e.g. an assignment left hand side). + -- This determination is conservative, it must never answer False if N is + -- an lvalue, but it can answer True when N is not an lvalue. An lvalue is + -- defined as any expression which appears in a context where a name is + -- required by the syntax, and the identity, rather than merely the value + -- of the node is needed (for example, the prefix of an attribute is in + -- this category). + function Is_Library_Level_Entity (E : Entity_Id) return Boolean; -- A library-level declaration is one that is accessible from Standard, -- i.e. a library unit or an entity declared in a library package. @@ -472,7 +513,7 @@ package Sem_Util is function Is_Selector_Name (N : Node_Id) return Boolean; -- Given an N_Identifier node N, determines if it is a Selector_Name. -- As described in Sinfo, Selector_Names are special because they - -- represent use of the N_Identifier node for a true identifier, when + -- represent use of the N_Identifier node for a true identifer, when -- normally such nodes represent a direct name. function Is_Statement (N : Node_Id) return Boolean; @@ -501,7 +542,24 @@ package Sem_Util is function Is_Volatile_Object (N : Node_Id) return Boolean; -- Determines if the given node denotes an volatile object in the sense - -- of the legality checks described in RM C.6(12). + -- of the legality checks described in RM C.6(12). Note that the test + -- here is for something actually declared as volatile, not for an object + -- that gets treated as volatile (see Einfo.Treat_As_Volatile). + + procedure Kill_Current_Values; + -- This procedure is called to clear all constant indications from all + -- entities in the current scope and in any parent scopes if the current + -- scope is a block or a pacakage (and that recursion continues to the + -- top scope that is not a block or a package). This is used when the + -- sequential flow-of-control assumption is violated (occurence of a + -- label, head of a loop, or start of an exception handler). The effect + -- of the call is to clear the Constant_Value field (but we do not need + -- to clear the Is_True_Constant flag, since that only gets reset if + -- there really is an assignment somewhere in the entity scope). This + -- procedure also calls Kill_All_Checks, since this is a special case + -- of needing to forget saved values. This procedure also clears any + -- Is_Known_Non_Null flags in variables, constants or parameters + -- since these are also not known to be valid. procedure Kill_Size_Check_Code (E : Entity_Id); -- Called when an address clause or pragma Import is applied to an @@ -516,8 +574,7 @@ package Sem_Util is Related_Id : Entity_Id; Suffix : Character; Suffix_Index : Nat := 0; - Prefix : Character := ' ') - return Entity_Id; + Prefix : Character := ' ') return Entity_Id; -- This function creates an N_Defining_Identifier node for an internal -- created entity, such as an implicit type or subtype, or a record -- initialization procedure. The entity name is constructed with a call @@ -531,8 +588,7 @@ package Sem_Util is (Kind : Entity_Kind; Scope_Id : Entity_Id; Sloc_Value : Source_Ptr; - Id_Char : Character) - return Entity_Id; + Id_Char : Character) return Entity_Id; -- This function is similar to New_External_Entity, except that the -- name is constructed by New_Internal_Name (Id_Char). This is used -- when the resulting entity does not have to be referenced as a @@ -557,7 +613,7 @@ package Sem_Util is Report : Boolean; Success : out Boolean); -- Reorders lists of actuals according to names of formals, value returned - -- in Success indicates success of reordering. For more details, see body. + -- in Success indicates sucess of reordering. For more details, see body. -- Errors are reported only if Report is set to True. procedure Note_Possible_Modification (N : Node_Id); @@ -596,6 +652,26 @@ package Sem_Util is -- S is a possibly signed syntactically valid real literal. The result -- returned is an N_Real_Literal node representing the literal value. + function Rep_To_Pos_Flag (E : Entity_Id; Loc : Source_Ptr) return Node_Id; + -- This is used to construct the second argument in a call to Rep_To_Pos + -- which is Standard_True if range checks are enabled (E is an entity to + -- which the Range_Checks_Suppressed test is applied), and Standard_False + -- if range checks are suppressed. Loc is the location for the node that + -- is returned (which is a New_Occurrence of the appropriate entity). + -- + -- Note: one might think that it would be fine to always use True and + -- to ignore the suppress in this case, but it is generally better to + -- believe a request to suppress exceptions if possible, and further + -- more there is at least one case in the generated code (the code for + -- array assignment in a loop) that depends on this suppression. + + procedure Require_Entity (N : Node_Id); + -- N is a node which should have an entity value if it is an entity name. + -- If not, then check if there were previous errors. If so, just fill + -- in with Any_Id and ignore. Otherwise signal a program error exception. + -- This is used as a defense mechanism against ill-formed trees caused by + -- previous errors (particularly in -gnatq mode). + function Requires_Transient_Scope (Id : Entity_Id) return Boolean; -- E is a type entity. The result is True when temporaries of this -- type need to be wrapped in a transient scope to be reclaimed @@ -606,6 +682,18 @@ package Sem_Util is procedure Reset_Analyzed_Flags (N : Node_Id); -- Reset the Analyzed flags in all nodes of the tree whose root is N + function Safe_To_Capture_Value + (N : Node_Id; + Ent : Entity_Id) + return Boolean; + -- The caller is interested in capturing a value (either the current + -- value, or an indication that the value is non-null) for the given + -- entity Ent. This value can only be captured if sequential execution + -- semantics can be properly guaranteed so that a subsequent reference + -- will indeed be sure that this current value indication is correct. + -- The node N is the construct which resulted in the possible capture + -- of the value (this is used to check if we are in a conditional). + function Same_Name (N1, N2 : Node_Id) return Boolean; -- Determine if two (possibly expanded) names are the same name @@ -693,12 +781,15 @@ package Sem_Util is function Unit_Declaration_Node (Unit_Id : Entity_Id) return Node_Id; -- Unit_Id is the simple name of a program unit, this function returns -- the corresponding xxx_Declaration node for the entity. Also applies - -- to the body entities for subprograms in tasks, in which case it - -- returns the subprogram or task body node for it. The unit may be - -- a child unit with any number of ancestors. + -- to the body entities for subprograms, tasks and protected units, in + -- which case it returns the subprogram, task or protected body node + -- for it. The unit may be a child unit with any number of ancestors. + + function Universal_Interpretation (Opnd : Node_Id) return Entity_Id; + -- Yields universal_Integer or Universal_Real if this is a candidate. function Within_Init_Proc return Boolean; - -- Determines if Current_Scope is within an Init_Proc + -- Determines if Current_Scope is within an init proc procedure Wrong_Type (Expr : Node_Id; Expected_Type : Entity_Id); -- Output error message for incorrectly typed expression. Expr is the |