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+------------------------------------------------------------------------------
+-- --
+-- GNAT COMPILER COMPONENTS --
+-- --
+-- A S P E C T S --
+-- --
+-- S p e c --
+-- --
+-- Copyright (C) 2010-2013, 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 3, 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. --
+-- --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
+-- --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
+-- --
+-- GNAT was originally developed by the GNAT team at New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc. --
+-- --
+------------------------------------------------------------------------------
+
+-- This package defines the aspects that are recognized by GNAT in aspect
+-- specifications. It also contains the subprograms for storing/retrieving
+-- aspect specifications from the tree. The semantic processing for aspect
+-- specifications is found in Sem_Ch13.Analyze_Aspect_Specifications.
+
+------------------------
+-- Adding New Aspects --
+------------------------
+
+-- In general, each aspect should have a corresponding pragma, so that the
+-- newly developed functionality is available for Ada versions < Ada 2012.
+-- When both are defined, it is convenient to first transform the aspect into
+-- an equivalent pragma in Sem_Ch13.Analyze_Aspect_Specifications, and then
+-- analyze the pragma in Sem_Prag.Analyze_Pragma.
+
+-- To add a new aspect, you need to do the following
+
+-- 1. Create a name in snames.ads-tmpl
+
+-- 2. Create a value in type Aspect_Id in this unit
+
+-- 3. Add a value for the aspect in the global arrays defined in this unit
+
+-- 4. Add code for the aspect in Sem_Ch13.Analyze_Aspect_Specifications.
+-- This may involve adding some nodes to the tree to perform additional
+-- treatments later.
+
+-- 5. If the semantic analysis of expressions/names in the aspect should not
+-- occur at the point the aspect is defined, add code in the adequate
+-- semantic analysis procedure for the aspect. For example, this is the
+-- case for aspects Pre and Post on subprograms, which are pre-analyzed
+-- at the end of the declaration list to which the subprogram belongs,
+-- and fully analyzed (possibly with expansion) during the semantic
+-- analysis of subprogram bodies.
+
+with Namet; use Namet;
+with Snames; use Snames;
+with Types; use Types;
+
+package Aspects is
+
+ -- Type defining recognized aspects
+
+ type Aspect_Id is
+ (No_Aspect, -- Dummy entry for no aspect
+ Aspect_Abstract_State, -- GNAT
+ Aspect_Address,
+ Aspect_Alignment,
+ Aspect_Attach_Handler,
+ Aspect_Bit_Order,
+ Aspect_Component_Size,
+ Aspect_Constant_Indexing,
+ Aspect_Contract_Cases, -- GNAT
+ Aspect_Convention,
+ Aspect_CPU,
+ Aspect_Default_Component_Value,
+ Aspect_Default_Iterator,
+ Aspect_Default_Value,
+ Aspect_Depends, -- GNAT
+ Aspect_Dimension, -- GNAT
+ Aspect_Dimension_System, -- GNAT
+ Aspect_Dispatching_Domain,
+ Aspect_Dynamic_Predicate,
+ Aspect_External_Name,
+ Aspect_External_Tag,
+ Aspect_Global, -- GNAT
+ Aspect_Implicit_Dereference,
+ Aspect_Initial_Condition, -- GNAT
+ Aspect_Initializes, -- GNAT
+ Aspect_Input,
+ Aspect_Interrupt_Priority,
+ Aspect_Invariant, -- GNAT
+ Aspect_Iterator_Element,
+ Aspect_Iterable, -- GNAT
+ Aspect_Link_Name,
+ Aspect_Linker_Section, -- GNAT
+ Aspect_Machine_Radix,
+ Aspect_Object_Size, -- GNAT
+ Aspect_Output,
+ Aspect_Part_Of, -- GNAT
+ Aspect_Post,
+ Aspect_Postcondition,
+ Aspect_Pre,
+ Aspect_Precondition,
+ Aspect_Predicate, -- GNAT
+ Aspect_Priority,
+ Aspect_Read,
+ Aspect_Refined_Depends, -- GNAT
+ Aspect_Refined_Global, -- GNAT
+ Aspect_Refined_Post, -- GNAT
+ Aspect_Refined_State, -- GNAT
+ Aspect_Relative_Deadline,
+ Aspect_Scalar_Storage_Order, -- GNAT
+ Aspect_Simple_Storage_Pool, -- GNAT
+ Aspect_Size,
+ Aspect_Small,
+ Aspect_SPARK_Mode, -- GNAT
+ Aspect_Static_Predicate,
+ Aspect_Storage_Pool,
+ Aspect_Storage_Size,
+ Aspect_Stream_Size,
+ Aspect_Suppress,
+ Aspect_Synchronization,
+ Aspect_Test_Case, -- GNAT
+ Aspect_Type_Invariant,
+ Aspect_Unsuppress,
+ Aspect_Value_Size, -- GNAT
+ Aspect_Variable_Indexing,
+ Aspect_Warnings, -- GNAT
+ Aspect_Write,
+
+ -- The following aspects correspond to library unit pragmas
+
+ Aspect_All_Calls_Remote,
+ Aspect_Elaborate_Body,
+ Aspect_Preelaborate,
+ Aspect_Pure,
+ Aspect_Remote_Call_Interface,
+ Aspect_Remote_Types,
+ Aspect_Shared_Passive,
+ Aspect_Universal_Data, -- GNAT
+
+ -- Remaining aspects have a static boolean value that turns the aspect
+ -- on or off. They all correspond to pragmas, but are only converted to
+ -- the pragmas where the value is True. A value of False normally means
+ -- that the aspect is ignored, except in the case of derived types where
+ -- the aspect value is inherited from the parent, in which case, we do
+ -- not allow False if we inherit a True value from the parent.
+
+ Aspect_Async_Readers, -- GNAT
+ Aspect_Async_Writers, -- GNAT
+ Aspect_Asynchronous,
+ Aspect_Atomic,
+ Aspect_Atomic_Components,
+ Aspect_Discard_Names,
+ Aspect_Effective_Reads, -- GNAT
+ Aspect_Effective_Writes, -- GNAT
+ Aspect_Export,
+ Aspect_Favor_Top_Level, -- GNAT
+ Aspect_Independent,
+ Aspect_Independent_Components,
+ Aspect_Import,
+ Aspect_Inline,
+ Aspect_Inline_Always, -- GNAT
+ Aspect_Interrupt_Handler,
+ Aspect_No_Return,
+ Aspect_Pack,
+ Aspect_Persistent_BSS, -- GNAT
+ Aspect_Preelaborable_Initialization,
+ Aspect_Pure_Function, -- GNAT
+ Aspect_Remote_Access_Type, -- GNAT
+ Aspect_Shared, -- GNAT (equivalent to Atomic)
+ Aspect_Simple_Storage_Pool_Type, -- GNAT
+ Aspect_Suppress_Debug_Info, -- GNAT
+ Aspect_Unchecked_Union,
+ Aspect_Universal_Aliasing, -- GNAT
+ Aspect_Unmodified, -- GNAT
+ Aspect_Unreferenced, -- GNAT
+ Aspect_Unreferenced_Objects, -- GNAT
+ Aspect_Volatile,
+ Aspect_Volatile_Components,
+
+ -- Aspects that have a static boolean value but don't correspond to
+ -- pragmas
+
+ Aspect_Lock_Free); -- GNAT
+
+ subtype Aspect_Id_Exclude_No_Aspect is
+ Aspect_Id range Aspect_Id'Succ (No_Aspect) .. Aspect_Id'Last;
+ -- Aspect_Id's excluding No_Aspect
+
+ -- The following array indicates aspects that accept 'Class
+
+ Class_Aspect_OK : constant array (Aspect_Id) of Boolean :=
+ (Aspect_Invariant => True,
+ Aspect_Pre => True,
+ Aspect_Predicate => True,
+ Aspect_Post => True,
+ Aspect_Type_Invariant => True,
+ others => False);
+
+ -- The following array identifies all implementation defined aspects
+
+ Implementation_Defined_Aspect : constant array (Aspect_Id) of Boolean :=
+ (Aspect_Abstract_State => True,
+ Aspect_Async_Readers => True,
+ Aspect_Async_Writers => True,
+ Aspect_Contract_Cases => True,
+ Aspect_Depends => True,
+ Aspect_Dimension => True,
+ Aspect_Dimension_System => True,
+ Aspect_Effective_Reads => True,
+ Aspect_Effective_Writes => True,
+ Aspect_Favor_Top_Level => True,
+ Aspect_Global => True,
+ Aspect_Inline_Always => True,
+ Aspect_Invariant => True,
+ Aspect_Lock_Free => True,
+ Aspect_Object_Size => True,
+ Aspect_Persistent_BSS => True,
+ Aspect_Predicate => True,
+ Aspect_Pure_Function => True,
+ Aspect_Remote_Access_Type => True,
+ Aspect_Scalar_Storage_Order => True,
+ Aspect_Shared => True,
+ Aspect_Simple_Storage_Pool => True,
+ Aspect_Simple_Storage_Pool_Type => True,
+ Aspect_Suppress_Debug_Info => True,
+ Aspect_Test_Case => True,
+ Aspect_Universal_Aliasing => True,
+ Aspect_Universal_Data => True,
+ Aspect_Unmodified => True,
+ Aspect_Unreferenced => True,
+ Aspect_Unreferenced_Objects => True,
+ Aspect_Value_Size => True,
+ Aspect_Warnings => True,
+ others => False);
+
+ -- The following array indicates aspects for which multiple occurrences of
+ -- the same aspect attached to the same declaration are allowed.
+
+ No_Duplicates_Allowed : constant array (Aspect_Id) of Boolean :=
+ (Aspect_Test_Case => False,
+ others => True);
+
+ -- The following subtype defines aspects corresponding to library unit
+ -- pragmas, these can only validly appear as aspects for library units,
+ -- and result in a corresponding pragma being inserted immediately after
+ -- the occurrence of the aspect.
+
+ subtype Library_Unit_Aspects is
+ Aspect_Id range Aspect_All_Calls_Remote .. Aspect_Universal_Data;
+
+ -- The following subtype defines aspects accepting an optional static
+ -- boolean parameter indicating if the aspect should be active or
+ -- cancelling. If the parameter is missing the effective value is True,
+ -- enabling the aspect. If the parameter is present it must be a static
+ -- expression of type Standard.Boolean. If the value is True, then the
+ -- aspect is enabled. If it is False, the aspect is disabled.
+
+ subtype Boolean_Aspects is
+ Aspect_Id range Aspect_Async_Readers .. Aspect_Id'Last;
+
+ subtype Pre_Post_Aspects is
+ Aspect_Id range Aspect_Post .. Aspect_Precondition;
+
+ -- The following type is used for indicating allowed expression forms
+
+ type Aspect_Expression is
+ (Expression, -- Required expression
+ Name, -- Required name
+ Optional_Expression, -- Optional boolean expression
+ Optional_Name); -- Optional name
+
+ -- The following array indicates what argument type is required
+
+ Aspect_Argument : constant array (Aspect_Id) of Aspect_Expression :=
+ (No_Aspect => Optional_Expression,
+ Aspect_Abstract_State => Expression,
+ Aspect_Address => Expression,
+ Aspect_Alignment => Expression,
+ Aspect_Attach_Handler => Expression,
+ Aspect_Bit_Order => Expression,
+ Aspect_Component_Size => Expression,
+ Aspect_Constant_Indexing => Name,
+ Aspect_Contract_Cases => Expression,
+ Aspect_Convention => Name,
+ Aspect_CPU => Expression,
+ Aspect_Default_Component_Value => Expression,
+ Aspect_Default_Iterator => Name,
+ Aspect_Default_Value => Expression,
+ Aspect_Depends => Expression,
+ Aspect_Dimension => Expression,
+ Aspect_Dimension_System => Expression,
+ Aspect_Dispatching_Domain => Expression,
+ Aspect_Dynamic_Predicate => Expression,
+ Aspect_External_Name => Expression,
+ Aspect_External_Tag => Expression,
+ Aspect_Global => Expression,
+ Aspect_Implicit_Dereference => Name,
+ Aspect_Initial_Condition => Expression,
+ Aspect_Initializes => Expression,
+ Aspect_Input => Name,
+ Aspect_Interrupt_Priority => Expression,
+ Aspect_Invariant => Expression,
+ Aspect_Iterable => Expression,
+ Aspect_Iterator_Element => Name,
+ Aspect_Link_Name => Expression,
+ Aspect_Linker_Section => Expression,
+ Aspect_Machine_Radix => Expression,
+ Aspect_Object_Size => Expression,
+ Aspect_Output => Name,
+ Aspect_Part_Of => Expression,
+ Aspect_Post => Expression,
+ Aspect_Postcondition => Expression,
+ Aspect_Pre => Expression,
+ Aspect_Precondition => Expression,
+ Aspect_Predicate => Expression,
+ Aspect_Priority => Expression,
+ Aspect_Read => Name,
+ Aspect_Refined_Depends => Expression,
+ Aspect_Refined_Global => Expression,
+ Aspect_Refined_Post => Expression,
+ Aspect_Refined_State => Expression,
+ Aspect_Relative_Deadline => Expression,
+ Aspect_Scalar_Storage_Order => Expression,
+ Aspect_Simple_Storage_Pool => Name,
+ Aspect_Size => Expression,
+ Aspect_Small => Expression,
+ Aspect_SPARK_Mode => Optional_Name,
+ Aspect_Static_Predicate => Expression,
+ Aspect_Storage_Pool => Name,
+ Aspect_Storage_Size => Expression,
+ Aspect_Stream_Size => Expression,
+ Aspect_Suppress => Name,
+ Aspect_Synchronization => Name,
+ Aspect_Test_Case => Expression,
+ Aspect_Type_Invariant => Expression,
+ Aspect_Unsuppress => Name,
+ Aspect_Value_Size => Expression,
+ Aspect_Variable_Indexing => Name,
+ Aspect_Warnings => Name,
+ Aspect_Write => Name,
+
+ Boolean_Aspects => Optional_Expression,
+ Library_Unit_Aspects => Optional_Expression);
+
+ -----------------------------------------
+ -- Table Linking Names and Aspect_Id's --
+ -----------------------------------------
+
+ -- Table linking aspect names and id's
+
+ Aspect_Names : constant array (Aspect_Id) of Name_Id :=
+ (No_Aspect => No_Name,
+ Aspect_Abstract_State => Name_Abstract_State,
+ Aspect_Address => Name_Address,
+ Aspect_Alignment => Name_Alignment,
+ Aspect_All_Calls_Remote => Name_All_Calls_Remote,
+ Aspect_Async_Readers => Name_Async_Readers,
+ Aspect_Async_Writers => Name_Async_Writers,
+ Aspect_Asynchronous => Name_Asynchronous,
+ Aspect_Atomic => Name_Atomic,
+ Aspect_Atomic_Components => Name_Atomic_Components,
+ Aspect_Attach_Handler => Name_Attach_Handler,
+ Aspect_Bit_Order => Name_Bit_Order,
+ Aspect_Component_Size => Name_Component_Size,
+ Aspect_Constant_Indexing => Name_Constant_Indexing,
+ Aspect_Contract_Cases => Name_Contract_Cases,
+ Aspect_Convention => Name_Convention,
+ Aspect_CPU => Name_CPU,
+ Aspect_Default_Iterator => Name_Default_Iterator,
+ Aspect_Default_Value => Name_Default_Value,
+ Aspect_Default_Component_Value => Name_Default_Component_Value,
+ Aspect_Depends => Name_Depends,
+ Aspect_Dimension => Name_Dimension,
+ Aspect_Dimension_System => Name_Dimension_System,
+ Aspect_Discard_Names => Name_Discard_Names,
+ Aspect_Dispatching_Domain => Name_Dispatching_Domain,
+ Aspect_Dynamic_Predicate => Name_Dynamic_Predicate,
+ Aspect_Effective_Reads => Name_Effective_Reads,
+ Aspect_Effective_Writes => Name_Effective_Writes,
+ Aspect_Elaborate_Body => Name_Elaborate_Body,
+ Aspect_External_Name => Name_External_Name,
+ Aspect_External_Tag => Name_External_Tag,
+ Aspect_Export => Name_Export,
+ Aspect_Favor_Top_Level => Name_Favor_Top_Level,
+ Aspect_Global => Name_Global,
+ Aspect_Implicit_Dereference => Name_Implicit_Dereference,
+ Aspect_Import => Name_Import,
+ Aspect_Independent => Name_Independent,
+ Aspect_Independent_Components => Name_Independent_Components,
+ Aspect_Inline => Name_Inline,
+ Aspect_Inline_Always => Name_Inline_Always,
+ Aspect_Initial_Condition => Name_Initial_Condition,
+ Aspect_Initializes => Name_Initializes,
+ Aspect_Input => Name_Input,
+ Aspect_Interrupt_Handler => Name_Interrupt_Handler,
+ Aspect_Interrupt_Priority => Name_Interrupt_Priority,
+ Aspect_Invariant => Name_Invariant,
+ Aspect_Iterator_Element => Name_Iterator_Element,
+ Aspect_Iterable => Name_Iterable,
+ Aspect_Link_Name => Name_Link_Name,
+ Aspect_Linker_Section => Name_Linker_Section,
+ Aspect_Lock_Free => Name_Lock_Free,
+ Aspect_Machine_Radix => Name_Machine_Radix,
+ Aspect_No_Return => Name_No_Return,
+ Aspect_Object_Size => Name_Object_Size,
+ Aspect_Output => Name_Output,
+ Aspect_Pack => Name_Pack,
+ Aspect_Part_Of => Name_Part_Of,
+ Aspect_Persistent_BSS => Name_Persistent_BSS,
+ Aspect_Post => Name_Post,
+ Aspect_Postcondition => Name_Postcondition,
+ Aspect_Pre => Name_Pre,
+ Aspect_Precondition => Name_Precondition,
+ Aspect_Predicate => Name_Predicate,
+ Aspect_Preelaborable_Initialization => Name_Preelaborable_Initialization,
+ Aspect_Preelaborate => Name_Preelaborate,
+ Aspect_Priority => Name_Priority,
+ Aspect_Pure => Name_Pure,
+ Aspect_Pure_Function => Name_Pure_Function,
+ Aspect_Read => Name_Read,
+ Aspect_Refined_Depends => Name_Refined_Depends,
+ Aspect_Refined_Global => Name_Refined_Global,
+ Aspect_Refined_Post => Name_Refined_Post,
+ Aspect_Refined_State => Name_Refined_State,
+ Aspect_Relative_Deadline => Name_Relative_Deadline,
+ Aspect_Remote_Access_Type => Name_Remote_Access_Type,
+ Aspect_Remote_Call_Interface => Name_Remote_Call_Interface,
+ Aspect_Remote_Types => Name_Remote_Types,
+ Aspect_Scalar_Storage_Order => Name_Scalar_Storage_Order,
+ Aspect_Shared => Name_Shared,
+ Aspect_Shared_Passive => Name_Shared_Passive,
+ Aspect_Simple_Storage_Pool => Name_Simple_Storage_Pool,
+ Aspect_Simple_Storage_Pool_Type => Name_Simple_Storage_Pool_Type,
+ Aspect_Size => Name_Size,
+ Aspect_Small => Name_Small,
+ Aspect_SPARK_Mode => Name_SPARK_Mode,
+ Aspect_Static_Predicate => Name_Static_Predicate,
+ Aspect_Storage_Pool => Name_Storage_Pool,
+ Aspect_Storage_Size => Name_Storage_Size,
+ Aspect_Stream_Size => Name_Stream_Size,
+ Aspect_Suppress => Name_Suppress,
+ Aspect_Suppress_Debug_Info => Name_Suppress_Debug_Info,
+ Aspect_Synchronization => Name_Synchronization,
+ Aspect_Test_Case => Name_Test_Case,
+ Aspect_Type_Invariant => Name_Type_Invariant,
+ Aspect_Unchecked_Union => Name_Unchecked_Union,
+ Aspect_Universal_Aliasing => Name_Universal_Aliasing,
+ Aspect_Universal_Data => Name_Universal_Data,
+ Aspect_Unmodified => Name_Unmodified,
+ Aspect_Unreferenced => Name_Unreferenced,
+ Aspect_Unreferenced_Objects => Name_Unreferenced_Objects,
+ Aspect_Unsuppress => Name_Unsuppress,
+ Aspect_Value_Size => Name_Value_Size,
+ Aspect_Variable_Indexing => Name_Variable_Indexing,
+ Aspect_Volatile => Name_Volatile,
+ Aspect_Volatile_Components => Name_Volatile_Components,
+ Aspect_Warnings => Name_Warnings,
+ Aspect_Write => Name_Write);
+
+ function Get_Aspect_Id (Name : Name_Id) return Aspect_Id;
+ pragma Inline (Get_Aspect_Id);
+ -- Given a name Nam, returns the corresponding aspect id value. If the name
+ -- does not match any aspect, then No_Aspect is returned as the result.
+
+ function Get_Aspect_Id (Aspect : Node_Id) return Aspect_Id;
+ pragma Inline (Get_Aspect_Id);
+ -- Given an aspect specification, return the corresponding aspect_id value.
+ -- If the name does not match any aspect, return No_Aspect.
+
+ ------------------------------------
+ -- Delaying Evaluation of Aspects --
+ ------------------------------------
+
+ -- The RM requires that all language defined aspects taking an expression
+ -- delay evaluation of the expression till the freeze point of the entity
+ -- to which the aspect applies. This allows forward references, and is of
+ -- use for example in connection with preconditions and postconditions
+ -- where the requirement of making all references in contracts to local
+ -- functions be backwards references would be onerous.
+
+ -- For consistency, even attributes like Size are delayed, so we can do:
+
+ -- type A is range 1 .. 10
+ -- with Size => Not_Defined_Yet;
+ -- ..
+ -- Not_Defined_Yet : constant := 64;
+
+ -- Resulting in A having a size of 64, which gets set when A is frozen.
+ -- Furthermore, we can have a situation like
+
+ -- type A is range 1 .. 10
+ -- with Size => Not_Defined_Yet;
+ -- ..
+ -- type B is new A;
+ -- ..
+ -- Not_Defined_Yet : constant := 64;
+
+ -- where the Size of A is considered to have been previously specified at
+ -- the point of derivation, even though the actual value of the size is
+ -- not known yet, and in this example B inherits the size value of 64.
+
+ -- Our normal implementation model (prior to Ada 2012) was simply to copy
+ -- inheritable attributes at the point of derivation. Then any subsequent
+ -- representation items apply either to the parent type, not affecting the
+ -- derived type, or to the derived type, not affecting the parent type.
+
+ -- To deal with the delayed aspect case, we use two flags. The first is
+ -- set on the parent type if it has delayed representation aspects. This
+ -- flag Has_Delayed_Rep_Aspects indicates that if we derive from this type
+ -- we have to worry about making sure we inherit any delayed aspects. The
+ -- second flag is set on a derived type: May_Have_Inherited_Rep_Aspects
+ -- is set if the parent type has Has_Delayed_Rep_Aspects set.
+
+ -- When we freeze a derived type, if the May_Have_Inherited_Rep_Aspects
+ -- flag is set, then we call Freeze.Inherit_Delayed_Rep_Aspects when
+ -- the derived type is frozen, which deals with the necessary copying of
+ -- information from the parent type, which must be frozen at that point
+ -- (since freezing the derived type first freezes the parent type).
+
+ -- The following shows which aspects are delayed. There are three cases:
+
+ type Delay_Type is
+ (Always_Delay,
+ -- This aspect is not a representation aspect that can be inherited and
+ -- is always delayed, as required by the language definition.
+
+ Never_Delay,
+ -- There are two cases. There are language defined aspects like
+ -- Convention where the "expression" is simply an uninterpreted
+ -- identifier, and there is no issue of evaluating it and thus no
+ -- issue of delaying the evaluation. The second case is implementation
+ -- defined aspects where we have decided that we don't want to allow
+ -- delays (and for our own aspects we can do what we like).
+
+ Rep_Aspect);
+ -- These are the cases of representation aspects that are in general
+ -- delayed, and where there is a potential issue of derived types that
+ -- inherit delayed representation values.
+
+ -- Note: even if this table indicates that an aspect is delayed, we never
+ -- delay Boolean aspects that have a missing expression (taken as True),
+ -- or expressions for delayed rep items that consist of an integer literal
+ -- (most cases of Size etc. in practice), since in these cases we know we
+ -- can get the value of the expression without delay. Note that we still
+ -- need to delay Boolean aspects that are specifically set to True:
+
+ -- type R is array (0 .. 31) of Boolean
+ -- with Pack => True;
+ -- True : constant Boolean := False;
+
+ -- This is nonsense, but we need to make it work and result in R not
+ -- being packed, and if we have something like:
+
+ -- type R is array (0 .. 31) of Boolean
+ -- with Pack => True;
+ -- RR : R;
+ -- True : constant Boolean := False;
+
+ -- This is illegal because the visibility of True changes after the freeze
+ -- point, which is not allowed, and we need the delay mechanism to properly
+ -- diagnose this error.
+
+ Aspect_Delay : constant array (Aspect_Id) of Delay_Type :=
+ (No_Aspect => Always_Delay,
+ Aspect_Address => Always_Delay,
+ Aspect_All_Calls_Remote => Always_Delay,
+ Aspect_Async_Readers => Always_Delay,
+ Aspect_Async_Writers => Always_Delay,
+ Aspect_Asynchronous => Always_Delay,
+ Aspect_Attach_Handler => Always_Delay,
+ Aspect_Constant_Indexing => Always_Delay,
+ Aspect_Contract_Cases => Always_Delay,
+ Aspect_CPU => Always_Delay,
+ Aspect_Default_Iterator => Always_Delay,
+ Aspect_Default_Value => Always_Delay,
+ Aspect_Default_Component_Value => Always_Delay,
+ Aspect_Depends => Always_Delay,
+ Aspect_Discard_Names => Always_Delay,
+ Aspect_Dispatching_Domain => Always_Delay,
+ Aspect_Dynamic_Predicate => Always_Delay,
+ Aspect_Effective_Reads => Always_Delay,
+ Aspect_Effective_Writes => Always_Delay,
+ Aspect_Elaborate_Body => Always_Delay,
+ Aspect_External_Name => Always_Delay,
+ Aspect_External_Tag => Always_Delay,
+ Aspect_Export => Always_Delay,
+ Aspect_Favor_Top_Level => Always_Delay,
+ Aspect_Global => Always_Delay,
+ Aspect_Implicit_Dereference => Always_Delay,
+ Aspect_Import => Always_Delay,
+ Aspect_Independent => Always_Delay,
+ Aspect_Independent_Components => Always_Delay,
+ Aspect_Inline => Always_Delay,
+ Aspect_Inline_Always => Always_Delay,
+ Aspect_Initial_Condition => Always_Delay,
+ Aspect_Initializes => Always_Delay,
+ Aspect_Input => Always_Delay,
+ Aspect_Interrupt_Handler => Always_Delay,
+ Aspect_Interrupt_Priority => Always_Delay,
+ Aspect_Invariant => Always_Delay,
+ Aspect_Iterable => Always_Delay,
+ Aspect_Iterator_Element => Always_Delay,
+ Aspect_Link_Name => Always_Delay,
+ Aspect_Linker_Section => Always_Delay,
+ Aspect_Lock_Free => Always_Delay,
+ Aspect_No_Return => Always_Delay,
+ Aspect_Output => Always_Delay,
+ Aspect_Persistent_BSS => Always_Delay,
+ Aspect_Post => Always_Delay,
+ Aspect_Postcondition => Always_Delay,
+ Aspect_Pre => Always_Delay,
+ Aspect_Precondition => Always_Delay,
+ Aspect_Predicate => Always_Delay,
+ Aspect_Preelaborable_Initialization => Always_Delay,
+ Aspect_Preelaborate => Always_Delay,
+ Aspect_Priority => Always_Delay,
+ Aspect_Pure => Always_Delay,
+ Aspect_Pure_Function => Always_Delay,
+ Aspect_Read => Always_Delay,
+ Aspect_Refined_Depends => Always_Delay,
+ Aspect_Refined_Global => Always_Delay,
+ Aspect_Refined_State => Always_Delay,
+ Aspect_Relative_Deadline => Always_Delay,
+ Aspect_Remote_Access_Type => Always_Delay,
+ Aspect_Remote_Call_Interface => Always_Delay,
+ Aspect_Remote_Types => Always_Delay,
+ Aspect_Shared => Always_Delay,
+ Aspect_Shared_Passive => Always_Delay,
+ Aspect_Simple_Storage_Pool => Always_Delay,
+ Aspect_Simple_Storage_Pool_Type => Always_Delay,
+ Aspect_Static_Predicate => Always_Delay,
+ Aspect_Storage_Pool => Always_Delay,
+ Aspect_Stream_Size => Always_Delay,
+ Aspect_Suppress => Always_Delay,
+ Aspect_Suppress_Debug_Info => Always_Delay,
+ Aspect_Type_Invariant => Always_Delay,
+ Aspect_Unchecked_Union => Always_Delay,
+ Aspect_Universal_Aliasing => Always_Delay,
+ Aspect_Universal_Data => Always_Delay,
+ Aspect_Unmodified => Always_Delay,
+ Aspect_Unreferenced => Always_Delay,
+ Aspect_Unreferenced_Objects => Always_Delay,
+ Aspect_Unsuppress => Always_Delay,
+ Aspect_Variable_Indexing => Always_Delay,
+ Aspect_Write => Always_Delay,
+
+ Aspect_Abstract_State => Never_Delay,
+ Aspect_Convention => Never_Delay,
+ Aspect_Dimension => Never_Delay,
+ Aspect_Dimension_System => Never_Delay,
+ Aspect_Part_Of => Never_Delay,
+ Aspect_Refined_Post => Never_Delay,
+ Aspect_SPARK_Mode => Never_Delay,
+ Aspect_Synchronization => Never_Delay,
+ Aspect_Test_Case => Never_Delay,
+ Aspect_Warnings => Never_Delay,
+
+ Aspect_Alignment => Rep_Aspect,
+ Aspect_Atomic => Rep_Aspect,
+ Aspect_Atomic_Components => Rep_Aspect,
+ Aspect_Bit_Order => Rep_Aspect,
+ Aspect_Component_Size => Rep_Aspect,
+ Aspect_Machine_Radix => Rep_Aspect,
+ Aspect_Object_Size => Rep_Aspect,
+ Aspect_Pack => Rep_Aspect,
+ Aspect_Scalar_Storage_Order => Rep_Aspect,
+ Aspect_Size => Rep_Aspect,
+ Aspect_Small => Rep_Aspect,
+ Aspect_Storage_Size => Rep_Aspect,
+ Aspect_Value_Size => Rep_Aspect,
+ Aspect_Volatile => Rep_Aspect,
+ Aspect_Volatile_Components => Rep_Aspect);
+
+ ------------------------------------------------
+ -- Handling of Aspect Specifications on Stubs --
+ ------------------------------------------------
+
+ -- Aspects that appear on the following stub nodes
+
+ -- N_Package_Body_Stub
+ -- N_Protected_Body_Stub
+ -- N_Subprogram_Body_Stub
+ -- N_Task_Body_Stub
+
+ -- are treated as if they apply to the corresponding proper body. Their
+ -- analysis is postponed until the analysis of the proper body takes place
+ -- (see Analyze_Proper_Body). The delay is required because the analysis
+ -- may generate extra code which would be harder to relocate to the body.
+ -- If the proper body is present, the aspect specifications are relocated
+ -- to the corresponding body node:
+
+ -- N_Package_Body
+ -- N_Protected_Body
+ -- N_Subprogram_Body
+ -- N_Task_Body
+
+ -- The subsequent analysis takes care of the aspect-to-pragma conversions
+ -- and verification of pragma legality. In the case where the proper body
+ -- is not available, the aspect specifications are analyzed on the spot
+ -- (see Analyze_Proper_Body) to catch potential errors.
+
+ -- The following table lists all aspects that can apply to a subprogram
+ -- body [stub]. For instance, the following example is legal:
+
+ -- package P with SPARK_Mode ...;
+ -- package body P with SPARK_Mode is ...;
+
+ -- The table should be synchronized with Pragma_On_Body_Or_Stub_OK in unit
+ -- Sem_Prag if the aspects below are implemented by a pragma.
+
+ Aspect_On_Body_Or_Stub_OK : constant array (Aspect_Id) of Boolean :=
+ (Aspect_Refined_Depends => True,
+ Aspect_Refined_Global => True,
+ Aspect_Refined_Post => True,
+ Aspect_SPARK_Mode => True,
+ Aspect_Warnings => True,
+ others => False);
+
+ ---------------------------------------------------
+ -- Handling of Aspect Specifications in the Tree --
+ ---------------------------------------------------
+
+ -- Several kinds of declaration node permit aspect specifications in Ada
+ -- 2012 mode. If there was room in all the corresponding declaration nodes,
+ -- we could just have a field Aspect_Specifications pointing to a list of
+ -- nodes for the aspects (N_Aspect_Specification nodes). But there isn't
+ -- room, so we adopt a different approach.
+
+ -- The following subprograms provide access to a specialized interface
+ -- implemented internally with a hash table in the body, that provides
+ -- access to aspect specifications.
+
+ function Aspect_Specifications (N : Node_Id) return List_Id;
+ -- Given a node N, returns the list of N_Aspect_Specification nodes that
+ -- are attached to this declaration node. If the node is in the class of
+ -- declaration nodes that permit aspect specifications, as defined by the
+ -- predicate above, and if their Has_Aspects flag is set to True, then this
+ -- will always be a non-empty list. If this flag is set to False, then
+ -- No_List is returned. Normally, the only nodes that have Has_Aspects set
+ -- True are the nodes for which Permits_Aspect_Specifications would return
+ -- True (i.e. the declaration nodes defined in the RM as permitting the
+ -- presence of Aspect_Specifications). However, it is possible for the
+ -- flag Has_Aspects to be set on other nodes as a result of Rewrite and
+ -- Replace calls, and this function may be used to retrieve the aspect
+ -- specifications for the original rewritten node in such cases.
+
+ function Aspects_On_Body_Or_Stub_OK (N : Node_Id) return Boolean;
+ -- N denotes a body [stub] with aspects. Determine whether all aspects of N
+ -- are allowed to appear on a body [stub].
+
+ procedure Exchange_Aspects (N1 : Node_Id; N2 : Node_Id);
+ -- Exchange the aspect specifications of two nodes. If either node lacks an
+ -- aspect specification list, the routine has no effect. It is assumed that
+ -- both nodes can support aspects.
+
+ function Find_Aspect (Id : Entity_Id; A : Aspect_Id) return Node_Id;
+ -- Find the aspect specification of aspect A associated with entity I.
+ -- Return Empty if Id does not have the requested aspect.
+
+ function Find_Value_Of_Aspect
+ (Id : Entity_Id;
+ A : Aspect_Id) return Node_Id;
+ -- Find the value of aspect A associated with entity Id. Return Empty if
+ -- Id does not have the requested aspect.
+
+ function Has_Aspect (Id : Entity_Id; A : Aspect_Id) return Boolean;
+ -- Determine whether entity Id has aspect A
+
+ procedure Move_Aspects (From : Node_Id; To : Node_Id);
+ -- Relocate the aspect specifications of node From to node To. On entry it
+ -- is assumed that To does not have aspect specifications. If From has no
+ -- aspects, the routine has no effect.
+
+ procedure Move_Or_Merge_Aspects (From : Node_Id; To : Node_Id);
+ -- Relocate the aspect specifications of node From to node To. If To has
+ -- aspects, the aspects of From are added to the aspects of To. If From has
+ -- no aspects, the routine has no effect. When From denotes a subprogram
+ -- body stub that also acts as a spec, the only aspects relocated to node
+ -- To are those from table Aspect_On_Body_Or_Stub_OK and preconditions.
+
+ function Permits_Aspect_Specifications (N : Node_Id) return Boolean;
+ -- Returns True if the node N is a declaration node that permits aspect
+ -- specifications in the grammar. It is possible for other nodes to have
+ -- aspect specifications as a result of Rewrite or Replace calls.
+
+ procedure Remove_Aspects (N : Node_Id);
+ -- Delete the aspect specifications associated with node N. If the node has
+ -- no aspects, the routine has no effect.
+
+ function Same_Aspect (A1 : Aspect_Id; A2 : Aspect_Id) return Boolean;
+ -- Returns True if A1 and A2 are (essentially) the same aspect. This is not
+ -- a simple equality test because e.g. Post and Postcondition are the same.
+ -- This is used for detecting duplicate aspects.
+
+ procedure Set_Aspect_Specifications (N : Node_Id; L : List_Id);
+ -- The node N must be in the class of declaration nodes that permit aspect
+ -- specifications and the Has_Aspects flag must be False on entry. L must
+ -- be a non-empty list of N_Aspect_Specification nodes. This procedure sets
+ -- the Has_Aspects flag to True, and makes an entry that can be retrieved
+ -- by a subsequent Aspect_Specifications call. It is an error to call this
+ -- procedure with a node that does not permit aspect specifications, or a
+ -- node that has its Has_Aspects flag set True on entry, or with L being an
+ -- empty list or No_List.
+
+ procedure Tree_Read;
+ -- Reads contents of Aspect_Specifications hash table from the tree file
+
+ procedure Tree_Write;
+ -- Writes contents of Aspect_Specifications hash table to the tree file
+
+end Aspects;