2005-06-14 Ed Schonberg <schonberg@adacore.com>

	    Javier Miranda  <miranda@adacore.com>
	    Thomas Quinot  <quinot@adacore.com>
	    Robert Dewar  <dewar@adacore.com>
	    Hristian Kirtchev  <kirtchev@adacore.com>
	    Gary Dismukes  <dismukes@adacore.com>

	* einfo.ads, einfo.adb (Is_Local_Anonymous_Access): New flag on
	anonymous access types, to indicate that the accessibility level of
	the type is determined by that of the enclosing declaration.
	(Has_Persistent_BSS): New flag
	(Set_Is_Primitive_Wrapper): Upgrade the barrier to allow the usage
	of this attribute with functions.
	(Is_Primitive_Wrapper): Remove the barrier.
	(Has_Specified_Stream_Input, Has_Specified_Stream_Output,
	Has_Specified_Stream_Read, Has_Specified_Stream_Write):
	New subprograms.
	(Set_Has_Specified_Stream_Input, Set_Has_Specified_Stream_Output,
	Set_Has_Specified_Stream_Read, Set_Has_Specified_Stream_Write):
	New subprograms.
	(Is_Pure_Unit_Access_Type): New flag
	(Abstract_Interfaces): Complete the assertion to cover all usages.
	(Set_Is_Interface): Complete the assertion to cover all usages.
	(Is_Primitive_Wrapper): New attribute.
	(Is_Obsolescent): Now applies to all entities (though it is only set
	for subprograms currently)
	New flag:  Has_Constrained_Partial_View, to implemente Ada 2005 AI-363,
	which solves various problems concerning access subtypes.
	(Has_Persistent_BSS): New flag
	(Is_Primitive_Wrapper, Set_Primitive_Wrapper): Code cleanup.
	Remove these subprograms because this attribute is currently
	not used.
	New entity flags:
	Has_Specified_Stream_Input (Flag190)
	Has_Specified_Stream_Output (Flag191)
	Has_Specified_Stream_Read (Flag192)
	Has_Specified_Stream_Write (Flag193)
	Present in all type and subtype entities. Set for a given view if the
	corresponding stream-oriented attribute has been defined by an
	attribute definition clause. When such a clause occurs, a TSS is set
	on the underlying full view; the flags are used to track visibility of
	the attribute definition clause for partial or incomplete views.
	(Is_Pure_Unit_Access_Type): New flag
	Clarify use of Is_Internal.
	(Is_Primitive_Wrapper): New attribute present in primitive subprograms
	internally generated to wrap the invocation of tasks and protected
	types that implement interfaces.
	(Implementation_Base_Type): Documentation correction
	(Is_Obsolescent): Now applies to all entities (though it is only set
	for subprograms currently)
	New flag:  Has_Constrained_Partial_View, to implement Ada 2005 AI-363,
	which solves various problems concerning access subtypes.

	* exp_ch9.adb (Type_Conformant_Parameters): Introduce mode conformance
	for examined parameters. Identify unequal parameter list lengths as
	non-conformant parameters.
	(Overriding_Possible): Do not check for "All" qualifier in declaration
	of controlling access parameter, following prescription of AI-404.
	(Build_Entry_Wrapper_Spec, Build_Entry_Wrapper_Body): New subprograms
	that build the procedure body that wraps an entry invocation
	(Build_Corresponding_Record, Build_Protected_Sub_Specification,
	Expand_N_Protected_Body, Expand_N_Protected_Type_Declaration,
	Expand_N_Task_Body, Expand_N_Task_Type_Declaration): Modified to
	give support to abstract interface types

	* freeze.adb (Freeze_Entity): Issue error message if
	Is_Pure_Unit_Access_Type set, unless we are in Ada 2005 mode and the
	type has no storage pool (Ada 2005) AI-366.
	Also modified to give support to abstract interface types
	(Freeze_Subprogram): Issue an error for a dispatching subprogram with an
	Inline_Always pragma.

	* par-ch9.adb (P_Task_Items): Reserved words "not" or "overriding" may
	now begin an entry declaration.
	(P_Entry_Or_Subprogram_With_Indicator): New procedure in
	P_Protected_Operation_Declaration_Opt. Parse an entry declaration or
	a subprogram declaration preceded by an overriding indicator.
	(P_Protected_Operation_Declaration_Opt): Add case for parsing entry
	declarations or subprogram declarations preceded by reserved words
	"not" or "overriding".
	(P_Entry_Declaration): Update comment. Parse and check overriding
	indicator, set semantic flags of entry declarations.
	(P_Task): New error message in case of private applied
	to a task type declaration.
	(P_Protected): New error message in case of private applied
	to a task type declaration.

	* sem_ch7.adb (Preserve_Full_Attributes): Modified to handle the case
	in which the full view of a type implementing an interface is a
	concurrent type.
	(Has_Overriding_Pragma): Remove obsolete implementation of AI-218.
	Declare_Inherited_Private_Subprograms): If an explicit operation
	overrides an operation that is inherited in the private part, mark the
	explicit one as overriding, to enable overriding indicator checks.
	(Preserve_Full_Attributes): Propagate Is_Unchecked_Union attribute from
	full view to partial view, to simplify handling in back-end.

	* sprint.adb: Print interface lists where needed: derived types,
	protected types, task types.
	output "is null" for null procedures. Part of implementation of

	* sem_cat.adb (Validate_Access_Type_Declaration): Implement AI-366
	relaxation of rules for access types in pure, shared passive partitions.

	* exp_strm.adb (Build_Mutable_Record_Read_Procedure): Reorganize to
	first read discriminants into temporary objects, performing checks on
	the read values, then possibly performing discriminant checks on the
	actual (if it is constrained), and only finally reading the components
	into a constrained temporary object.
	(Build_Elementary_Input_Call): Adjust the specific circuitry for the
	case of reading discriminants of a mutable record type to recognize
	the new form of the code generated by
	Build_Mutable_Record_Read_Procedure.

	* exp_tss.ads, exp_tss.adb (Make_Init_Proc_Name): Reimplement in terms
	of a simple call to Make_TSS_Name.
	(Make_TSS_Name_Local): Add the TSS name as the last thing in the name
	buffer, in order for Is_TSS to work correctly on local TSS names.

	* sem_attr.ads, sem_attr.adb (Resolve_Attribute, case 'Access): Use flag
	Is_Local_Anonymous_Access to check legaliy of attributes in the
	context of  access components and stand-alone access objects.
	(Stream_Attribute_Available): In Ada 95 mode, a stream attribute is
	treated as available for a limited private type if there is an
	attribute_definition_clause that applies to its full view, but not in
	other cases where the attribute is available for the full view
	(specifically, the sole fact that the full view is non-limited does not
	make the attribute available for the partial view).
	(Build_Access_Subprogram_Type): Diagnose attempt to apply 'access to a
	non-overloaded intrinsic subprogram.
	(Check_Stream_Attribute): Reject an attribute reference for an
	unavailable stream attribute even if the prefix is not a limited type
	(case of a 'Input attribute reference for an abstract, non-classwide
	type)
	(Stream_Attribute_Available): New function to determine whether a stream
	attribute is available at a place.
	(Check_Attribute): Use Stream_Attribute_Available instead of just
	testing for TSS presence on the implementation base type.
	(Analyze_Attribute): Modified to give support to task interfaces.
	(Analyze_Access_Attribute): Add error check for use of an Access (or
	Unrestricted_Access) attribute with a subprogram marked as
	Inline_Always.
	(Analyze_Attribute, case Attribute_Address): Add error check for use of
	an Address attribute with a subprogram marked as Inline_Always.
	Update Eval_Attribute to handle new value of Width from AI-395

	* sem_ch13.adb (Analyze_Stream_TSS_Definition): New subprogram.
	(Analyze_Attribute_Definition_Clause, cases Input, Output, Read, Write):
	Factor common code across the stream-oriented attribute circcuits into
	a new subprogram, Analyze_Stream_TSS_Definition. The new uniform
	processing is functionally identical to the previous duplicated one,
	except that an expression that denotes an abstract subprogram will now
	be rejected, as mandated by AI-195 item 5.

	* sem_util.ads, sem_util.adb (Type_Access_Level): Use flag
	Is_Local_Anonymous_Access to apply accessibility checks to access
	components and stand-alone access objects.
	(Has_Discriminant_Dependent_Constraint): Moved to spec for use
	elsewhere.
	(Is_Potentially_Persistent_Type): New function
	(Is_Dependent_Component_Of_Mutable_Object): If the enclosing object is
	a heap-object whose type has a constrained partial view, the object is
	unconstrained and the component may depend on a discriminant, making its
	renaming illegal.

	* sinfo.ads, sinfo.adb
	(Must_Not_Override): Flag applicable to N_Entry_Declaration.
	(Must_Override): Flag applicable to N_Entry_Declaration.
	Indicate that interface_list can appear in single task and single
	protected declarations.
	Replace Is_Overriding and Not_Overriding with Must_Override and
	Must_Not_Override, to better express intent of AI.
	Is_Overriding, Not_Overriding: Ada2005 flags that indicate the presence
	of an overriding indicator in a subprogram or instance.
	Ada 2005 (AI-248) Null_Present can appear in a procedure specification.
	Add the overriding indicator [[not] overriding] construct to the
	following grammar productions:
	 ENTRY_DECLARATION
	 GENERIC_INSTANTIATION
	 SUBPROGRAM_SPECIFICATION

	* par-ch10.adb (P_Compilation_Unit): Subprogram declaration or body
	can start with an overriding indicator.

	* par-ch6.adb (P_Subprogram): Recognize overriding indicator, and set
	flags accordingly on subrogram specifications or instances.

	* sem_ch8.adb:
	(Analyze_Subprogram_Renaming): For a renaming_as_body, verify that the
	overriding_indicator, if present, is consistent with status of spec.
	Improve error message for null-excluding checks on controlling access
	parameters.
	(Check_In_Previous_With_Clause): Protect the frontend against
	previously reported critical errors in the context clauses.
	Save and restore Ada_Version_Explicit, for implementation of AI-362
	(Analyze_Subprogram_Renaming): If the new entity is a dispatching
	operation verify that controlling formals of the renamed entity that
	are access parameters are explicitly non-null.
	(Find_Expanded_Name): Improve error message when prefix is an illegal
	reference to a private child unit.

	* exp_imgv.adb, s-imgwch.ads, s-imgwch.adb, s-valwch.adb,
	s-valwch.ads, s-widwch.adb, s-widwch.ads, s-wwdcha.adb, s-wwdwch.adb:
	Rewrite to correspond to new wide character names in AI-395

        * par-ch12.adb (P_Formal_Subprogram_Declaration): Recognize null
        default procedures.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@101029 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 121 insertions, 142 deletions

diff --git a/gcc/ada/sem_attr.ads b/gcc/ada/sem_attr.ads
index 32e3eda9154..2a2c7b42917 100644
--- a/gcc/ada/sem_attr.ads
+++ b/gcc/ada/sem_attr.ads
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 1992-2003, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2005, 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- --
@@ -31,8 +31,9 @@
 
 --  This spec also documents all GNAT implementation defined pragmas
 
-with Snames; use Snames;
-with Types;  use Types;
+with Exp_Tss; use Exp_Tss;
+with Snames;  use Snames;
+with Types;   use Types;
 
 package Sem_Attr is
 
@@ -54,20 +55,18 @@ package Sem_Attr is
       ------------------
 
       Attribute_Abort_Signal => True,
-      --
-      --  Standard'Abort_Signal (Standard is the only allowed prefix)
-      --  provides the entity for the special exception used to signal
-      --  task abort or asynchronous transfer of control. Normally this
-      --  attribute should only be used in the tasking runtime (it is
-      --  highly peculiar, and completely outside the normal semantics
-      --  of Ada, for a user program to intercept the abort exception).
+      --  Standard'Abort_Signal (Standard is the only allowed prefix) provides
+      --  the entity for the special exception used to signal task abort or
+      --  asynchronous transfer of control. Normally this attribute should only
+      --  be used in the tasking runtime (it is highly peculiar, and completely
+      --  outside the normal semantics of Ada, for a user program to intercept
+      --  the abort exception).
 
       ------------------
       -- Address_Size --
       ------------------
 
       Attribute_Address_Size => True,
-      --
       --  Standard'Address_Size (Standard is the only allowed prefix) is
       --  a static constant giving the number of bits in an Address. It
       --  is used primarily for constructing the definition of Memory_Size
@@ -79,7 +78,6 @@ package Sem_Attr is
       ---------------
 
       Attribute_Asm_Input => True,
-      --
       --  Used only in conjunction with the Asm and Asm_Volatile subprograms
       --  in package Machine_Code to construct machine instructions. See
       --  documentation in package Machine_Code in file s-maccod.ads.
@@ -89,7 +87,6 @@ package Sem_Attr is
       ----------------
 
       Attribute_Asm_Output => True,
-      --
       --  Used only in conjunction with the Asm and Asm_Volatile subprograms
       --  in package Machine_Code to construct machine instructions. See
       --  documentation in package Machine_Code in file s-maccod.ads.
@@ -99,7 +96,6 @@ package Sem_Attr is
       ---------------
 
       Attribute_AST_Entry => True,
-      --
       --  E'Ast_Entry, where E is a task entry, yields a value of the
       --  predefined type System.DEC.AST_Handler, that enables the given
       --  entry to be called when an AST occurs. If the name to which the
@@ -117,20 +113,19 @@ package Sem_Attr is
       ---------
 
       Attribute_Bit => True,
-      --
-      --  Obj'Bit, where Obj is any object, yields the bit offset within
-      --  the storage unit (byte) that contains the first bit of storage
-      --  allocated for the object. The value of this attribute is of the
-      --  type Universal_Integer, and is always a non-negative number not
-      --  exceeding the value of System.Storage_Unit.
+      --  Obj'Bit, where Obj is any object, yields the bit offset within the
+      --  storage unit (byte) that contains the first bit of storage allocated
+      --  for the object. The attribute value is of type Universal_Integer,
+      --  and is always a non-negative number not exceeding the value of
+      --  System.Storage_Unit.
       --
       --  For an object that is a variable or a constant allocated in a
       --  register, the value is zero. (The use of this attribute does not
       --  force the allocation of a variable to memory).
       --
-      --  For an object that is a formal parameter, this attribute applies
-      --  to either the matching actual parameter or to a copy of the
-      --  matching actual parameter.
+      --  For an object that is a formal parameter, this attribute applies to
+      --  either the matching actual parameter or to a copy of the matching
+      --  actual parameter.
       --
       --  For an access object the value is zero. Note that Obj.all'Bit is
       --  subject to an Access_Check for the designated object. Similarly
@@ -145,22 +140,20 @@ package Sem_Attr is
       ------------------
 
       Attribute_Code_Address => True,
-      --
-      --  subp'Code_Address, where subp is a subprogram entity, gives the
-      --  address of the first generated instruction for a subprogram. This
-      --  is often, but not always the same as the 'Address value, which is
-      --  the address to be used in a call. The differences occur in the case
-      --  of a nested procedure (where Address yields the address of the
-      --  trampoline code used to load the static link), and on some systems
-      --  which use procedure descriptors (in which case Address yields the
-      --  address of the descriptor).
+      --  The reference subp'Code_Address, where subp is a subprogram entity,
+      --  gives the address of the first generated instruction for the sub-
+      --  program. This is often, but not always the same as the 'Address
+      --  value, which is the address to be used in a call. The differences
+      --  occur in the case of a nested procedure (where Address yields the
+      --  address of the trampoline code used to load the static link), and on
+      --  some systems which use procedure descriptors (in which case Address
+      --  yields the address of the descriptor).
 
       -----------------------
       -- Default_Bit_Order --
       -----------------------
 
       Attribute_Default_Bit_Order => True,
-      --
       --  Standard'Default_Bit_Order (Standard is the only permissible prefix),
       --  provides the value System.Default_Bit_Order as a Pos value (0 for
       --  High_Order_First, 1 for Low_Order_First). This is used to construct
@@ -172,22 +165,20 @@ package Sem_Attr is
       ---------------
 
       Attribute_Elab_Body => True,
-      --
-      --  This attribute can only be applied to a program unit name. It
-      --  returns the entity for the corresponding elaboration procedure
-      --  for elaborating the body of the referenced unit. This is used
-      --  in the main generated elaboration procedure by the binder, and
-      --  is not normally used in any other context, but there may be
-      --  specialized situations in which it is useful to be able to
-      --  call this elaboration procedure from Ada code, e.g. if it
-      --  is necessary to do selective reelaboration to fix some error.
+      --  This attribute can only be applied to a program unit name. It returns
+      --  the entity for the corresponding elaboration procedure for elabor-
+      --  ating the body of the referenced unit. This is used in the main
+      --  generated elaboration procedure by the binder, and is not normally
+      --  used in any other context, but there may be specialized situations in
+      --  which it is useful to be able to call this elaboration procedure from
+      --  Ada code, e.g. if it is necessary to do selective reelaboration to
+      --  fix some error.
 
       ---------------
       -- Elab_Spec --
       ---------------
 
       Attribute_Elab_Spec => True,
-      --
       --  This attribute can only be applied to a program unit name. It
       --  returns the entity for the corresponding elaboration procedure
       --  for elaborating the spec of the referenced unit. This is used
@@ -202,7 +193,6 @@ package Sem_Attr is
       ----------------
 
       Attribute_Elaborated => True,
-      --
       --  Lunit'Elaborated, where Lunit is a library unit, yields a boolean
       --  value indicating whether or not the body of the designated library
       --  unit has been elaborated yet.
@@ -212,7 +202,6 @@ package Sem_Attr is
       --------------
 
       Attribute_Enum_Rep => True,
-      --
       --  For every enumeration subtype S, S'Enum_Rep denotes a function
       --  with the following specification:
       --
@@ -228,7 +217,6 @@ package Sem_Attr is
       -----------------
 
       Attribute_Fixed_Value => True,
-      --
       --  For every fixed-point type S, S'Fixed_Value denotes a function
       --  with the following specification:
       --
@@ -238,18 +226,17 @@ package Sem_Attr is
       --
       --    V = Arg * S'Small
       --
-      --  The effect is thus equivalent to first converting the argument
-      --  to the integer type used to represent S, and then doing an
-      --  unchecked conversion to the fixed-point type. This attribute is
-      --  primarily intended for use in implementation of the input-output
-      --  functions for fixed-point values.
+      --  The effect is thus equivalent to first converting the argument to
+      --  the integer type used to represent S, and then doing an unchecked
+      --  conversion to the fixed-point type. This attribute is primarily
+      --  intended for use in implementation of the input-output functions for
+      --  fixed-point values.
 
       -----------------------
       -- Has_Discriminants --
       -----------------------
 
       Attribute_Has_Discriminants => True,
-      --
       --  Gtyp'Has_Discriminants, where Gtyp is a generic formal type, yields
       --  a Boolean value indicating whether or not the actual instantiation
       --  type has discriminants.
@@ -259,7 +246,6 @@ package Sem_Attr is
       ---------
 
       Attribute_Img => True,
-      --
       --  The 'Img function is defined for any prefix, P, that denotes an
       --  object of scalar type T. P'Img is equivalent to T'Image (P). This
       --  is convenient for debugging. For example:
@@ -277,7 +263,6 @@ package Sem_Attr is
       -------------------
 
       Attribute_Integer_Value => True,
-      --
       --  For every integer type S, S'Integer_Value denotes a function
       --  with the following specification:
       --
@@ -298,7 +283,6 @@ package Sem_Attr is
       ------------------
 
       Attribute_Machine_Size => True,
-      --
       --  This attribute is identical to the Object_Size attribute. It is
       --  provided for compatibility with the DEC attribute of this name.
 
@@ -307,7 +291,6 @@ package Sem_Attr is
       -----------------------
 
       Attribute_Maximum_Alignment => True,
-      --
       --  Standard'Maximum_Alignment (Standard is the only permissible prefix)
       --  provides the maximum useful alignment value for the target. This
       --  is a static value that can be used to specify the alignment for an
@@ -320,7 +303,6 @@ package Sem_Attr is
       --------------------
 
       Attribute_Mechanism_Code => True,
-      --
       --  function'Mechanism_Code yeilds an integer code for the mechanism
       --  used for the result of function, and subprogram'Mechanism_Code (n)
       --  yields the mechanism used for formal parameter number n (a static
@@ -342,64 +324,59 @@ package Sem_Attr is
       --------------------
 
       Attribute_Null_Parameter => True,
+      --  A reference T'Null_Parameter denotes an (imaginary) object of type or
+      --  subtype T allocated at (machine) address zero. The attribute is
+      --  allowed only as the default expression of a formal parameter, or as
+      --  an actual expression of a subporgram call. In either case, the
+      --  subprogram must be imported.
       --
-      --  A reference T'Null_Parameter denotes an (imaginary) object of
-      --  type or subtype T allocated at (machine) address zero. The
-      --  attribute is allowed only as the default expression of a formal
-      --  parameter, or as an actual expression of a subporgram call. In
-      --  either case, the subprogram must be imported.
-      --
-      --  The identity of the object is represented by the address zero
-      --  in the argument list, independent of the passing mechanism
-      --  (explicit or default).
+      --  The identity of the object is represented by the address zero in the
+      --  argument list, independent of the passing mechanism (explicit or
+      --  default).
       --
-      --  The reason that this capability is needed is that for a record
-      --  or other composite object passed by reference, there is no other
-      --  way of specifying that a zero address should be passed.
+      --  The reason that this capability is needed is that for a record or
+      --  other composite object passed by reference, there is no other way of
+      --  specifying that a zero address should be passed.
 
       -----------------
       -- Object_Size --
       -----------------
 
       Attribute_Object_Size => True,
-      --
       --  Type'Object_Size is the same as Type'Size for all types except
       --  fixed-point types and discrete types. For fixed-point types and
       --  discrete types, this attribute gives the size used for default
-      --  allocation of objects and components of the size. See section
-      --  in Einfo ("Handling of type'Size values") for further details.
+      --  allocation of objects and components of the size. See section in
+      --  Einfo ("Handling of type'Size values") for further details.
 
       -------------------------
       -- Passed_By_Reference --
       -------------------------
 
       Attribute_Passed_By_Reference => True,
-      --
-      --  T'Passed_By_Reference for any subtype T returns a boolean value
-      --  that is true if the type is normally passed by reference and
-      --  false if the type is normally passed by copy in calls. For scalar
-      --  types, the result is always False and is static. For non-scalar
-      --  types, the result is non-static (since it is computed by Gigi).
+      --  T'Passed_By_Reference for any subtype T returns a boolean value that
+      --  is true if the type is normally passed by reference and false if the
+      --  type is normally passed by copy in calls. For scalar types, the
+      --  result is always False and is static. For non-scalar types, the
+      --  result is non-static (since it is computed by Gigi).
 
       ------------------
       -- Range_Length --
       ------------------
 
       Attribute_Range_Length => True,
-      --
-      --  T'Range_Length for any discrete type T yields the number of
-      --  values represented by the subtype (zero for a null range). The
-      --  result is static for static subtypes. Note that Range_Length
-      --  applied to the index subtype of a one dimensional array always
-      --  gives the same result as Range applied to the array itself.
-      --  The result is of type universal integer.
+      --  T'Range_Length for any discrete type T yields the number of values
+      --  represented by the subtype (zero for a null range). The result is
+      --  static for static subtypes. Note that Range_Length applied to the
+      --  index subtype of a one dimensional array always gives the same result
+      --  as Range applied to the array itself. The result is of type universal
+      --  integer.
 
       ------------------
       -- Storage_Unit --
       ------------------
 
       Attribute_Storage_Unit => True,
-      --
       --  Standard'Storage_Unit (Standard is the only permissible prefix)
       --  provides the value System.Storage_Unit, and is intended primarily
       --  for constructing this definition in package System (see note above
@@ -410,36 +387,33 @@ package Sem_Attr is
       -----------------
 
       Attribute_Target_Name => True,
-      --
-      --  Standard'Target_Name yields the string identifying the target
-      --  for the compilation, taken from Sdefault.Target_Name.
+      --  Standard'Target_Name yields the string identifying the target for the
+      --  compilation, taken from Sdefault.Target_Name.
 
       ----------------
       -- To_Address --
       ----------------
 
       Attribute_To_Address => True,
-      --
-      --  System'To_Address (Address is the only permissible prefix)
-      --  is a function that takes any integer value, and converts it into
-      --  an address value. The semantics is to first convert the integer
-      --  value to type Integer_Address according to normal conversion
-      --  rules, and then to convert this to an address using the same
-      --  semantics as the System.Storage_Elements.To_Address function.
-      --  The important difference is that this is a static attribute
-      --  so it can be used in initializations in preealborate packages.
+      --  System'To_Address (Address is the only permissible prefix) is a
+      --  function that takes any integer value, and converts it into an
+      --  address value. The semantics is to first convert the integer value to
+      --  type Integer_Address according to normal conversion rules, and then
+      --  to convert this to an address using the same semantics as the
+      --  System.Storage_Elements.To_Address function. The important difference
+      --  is that this is a static attribute so it can be used in
+      --  initializations in preealborate packages.
 
       ----------------
       -- Type_Class --
       ----------------
 
       Attribute_Type_Class => True,
-      --
-      --  T'Type_Class for any type or subtype T yields the value of the
-      --  type class for the full type of T. If T is a generic formal type,
-      --  then the value is the value for the corresponding actual subtype.
-      --  The value of this attribute is of type System.Aux_DEC.Type_Class,
-      --  which has the following definition:
+      --  T'Type_Class for any type or subtype T yields the value of the type
+      --  class for the full type of T. If T is a generic formal type, then the
+      --  value is the value for the corresponding actual subtype. The value of
+      --  this attribute is of type System.Aux_DEC.Type_Class, which has the
+      --  following definition:
       --
       --    type Type_Class is
       --      (Type_Class_Enumeration,
@@ -452,9 +426,9 @@ package Sem_Attr is
       --       Type_Class_Task,
       --       Type_Class_Address);
       --
-      --  Protected types yield the value Type_Class_Task, which thus
-      --  applies to all concurrent types. This attribute is designed to
-      --  be compatible with the DEC Ada attribute of the same name.
+      --  Protected types yield the value Type_Class_Task, which thus applies
+      --  to all concurrent types. This attribute is designed to be compatible
+      --  with the DEC Ada attribute of the same name.
       --
       --  Note: if pragma Extend_System is used to merge the definitions of
       --  Aux_DEC into System, then the type Type_Class can be referenced
@@ -465,7 +439,6 @@ package Sem_Attr is
       -----------------
 
       Attribute_UET_Address => True,
-      --
       --  Unit'UET_Address, where Unit is a program unit, yields the address
       --  of the unit exception table for the specified unit. This is only
       --  used in the internal implementation of exception handling. See the
@@ -476,23 +449,21 @@ package Sem_Attr is
       ------------------------------
 
       Attribute_Universal_Literal_String => True,
-      --
-      --  The prefix of 'Universal_Literal_String must be a named number.
-      --  The static result is the string consisting of the characters of
-      --  the number as defined in the original source. This allows the
-      --  user program to access the actual text of named numbers without
-      --  intermediate conversions and without the need to enclose the
-      --  strings in quotes (which would preclude their use as numbers).
-      --  This is used internally for the construction of values of the
-      --  floating-point attributes from the file ttypef.ads, but may
-      --  also be used by user programs.
+      --  The prefix of 'Universal_Literal_String must be a named number. The
+      --  static result is the string consisting of the characters of the
+      --  number as defined in the original source. This allows the user
+      --  program to access the actual text of named numbers without
+      --  intermediate conversions and without the need to enclose the strings
+      --  in quotes (which would preclude their use as numbers). This is used
+      --  internally for the construction of values of the floating-point
+      --  attributes from the file ttypef.ads, but may also be used by user
+      --  programs.
 
       -------------------------
       -- Unrestricted_Access --
       -------------------------
 
       Attribute_Unrestricted_Access => True,
-      --
       --  The Unrestricted_Access attribute is similar to Access except that
       --  all accessibility and aliased view checks are omitted. This is very
       --  much a user-beware attribute. Basically its status is very similar
@@ -510,32 +481,28 @@ package Sem_Attr is
       ---------------
 
       Attribute_VADS_Size => True,
-      --
-      --  Typ'VADS_Size yields the Size value typically yielded by some
-      --  Ada 83 compilers. The differences between VADS_Size and Size
-      --  is that for scalar types for which no Size has been specified,
-      --  VADS_Size yields the Object_Size rather than the Value_Size.
-      --  For example, while Natural'Size is typically 31, the value of
-      --  Natural'VADS_Size is 32. For all other types, Size and VADS_Size
-      --  yield the same value.
+      --  Typ'VADS_Size yields the Size value typically yielded by some Ada 83
+      --  compilers. The differences between VADS_Size and Size is that for
+      --  scalar types for which no Size has been specified, VADS_Size yields
+      --  the Object_Size rather than the Value_Size. For example, while
+      --  Natural'Size is typically 31, the value of Natural'VADS_Size is 32.
+      --  For all other types, Size and VADS_Size yield the same value.
 
       ----------------
       -- Value_Size --
       ----------------
 
       Attribute_Value_Size => True,
-      --
-      --  Type'Value_Size is the number of bits required to represent a
-      --  value of the given subtype. It is the same as Type'Size, but,
-      --  unlike Size, may be set for non-first subtypes. See section
-      --  in Einfo ("Handling of type'Size values") for further details.
+      --  Type'Value_Size is the number of bits required to represent value of
+      --  the given subtype. It is the same as Type'Size, but, unlike Size, may
+      --  be set for non-first subtypes. See section in Einfo ("Handling of
+      --  type'Size values") for further details.
 
       ---------------
       -- Word_Size --
       ---------------
 
       Attribute_Word_Size => True,
-      --
       --  Standard'Word_Size (Standard is the only permissible prefix)
       --  provides the value System.Word_Size, and is intended primarily
       --  for constructing this definition in package System (see note above
@@ -554,14 +521,26 @@ package Sem_Attr is
    --  other attributes).
 
    procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id);
-   --  Performs type resolution of attribute. If the attribute yields
-   --  a universal value, mark its type as that of the context. On
-   --  the other hand, if the context itself is universal (as in
-   --  T'Val (T'Pos (X)), mark the type as being the largest type of
-   --  that class that can be used at run-time. This is correct since
-   --  either the value gets folded (in which case it doesn't matter
-   --  what type of the class we give if, since the folding uses universal
-   --  arithmetic anyway) or it doesn't get folded (in which case it is
-   --  going to be dealt with at runtime, and the largest type is right).
+   --  Performs type resolution of attribute. If the attribute yields a
+   --  universal value, mark its type as that of the context. On the other
+   --  hand, if the context itself is universal (as in T'Val (T'Pos (X)), mark
+   --  the type as being the largest type of that class that can be used at
+   --  run-time. This is correct since either the value gets folded (in which
+   --  case it doesn't matter what type of the class we give if, since the
+   --  folding uses universal arithmetic anyway) or it doesn't get folded (in
+   --  which case it is going to be dealt with at runtime, and the largest type
+   --  is right).
+
+   function Stream_Attribute_Available
+     (Typ          : Entity_Id;
+      Nam          : TSS_Name_Type;
+      Partial_View : Entity_Id := Empty) return Boolean;
+   --  For a limited type Typ, return True iff the given attribute is
+   --  available. For Ada 05, availability is defined by 13.13.2(36/1). For Ada
+   --  95, an attribute is considered to be available if it has been specified
+   --  using an attribute definition clause for the type, or for its full view,
+   --  or for an ancestor of either. Parameter Partial_View is used only
+   --  internally, when checking for an attribute definition clause that is not
+   --  visible (Ada 95 only).
 
 end Sem_Attr;