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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- A S P E C T S --
-- --
-- S p e c --
-- --
-- Copyright (C) 2010-2015, 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_Annotate, -- GNAT
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_Initial_Condition, -- GNAT
Aspect_Default_Iterator,
Aspect_Default_Storage_Pool,
Aspect_Default_Value,
Aspect_Depends, -- GNAT
Aspect_Dimension, -- GNAT
Aspect_Dimension_System, -- GNAT
Aspect_Dispatching_Domain,
Aspect_Dynamic_Predicate,
Aspect_Extensions_Visible, -- GNAT
Aspect_External_Name,
Aspect_External_Tag,
Aspect_Ghost, -- GNAT
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_Obsolescent, -- 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_Unimplemented, -- GNAT
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_No_Elaboration_Code_All, -- GNAT
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_Lock_Free, -- GNAT
Aspect_No_Return,
Aspect_No_Tagged_Streams, -- GNAT
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_Suppress_Initialization, -- GNAT
Aspect_Thread_Local_Storage, -- GNAT
Aspect_Unchecked_Union,
Aspect_Universal_Aliasing, -- GNAT
Aspect_Unmodified, -- GNAT
Aspect_Unreferenced, -- GNAT
Aspect_Unreferenced_Objects, -- GNAT
Aspect_Volatile,
Aspect_Volatile_Components);
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_Input => True,
Aspect_Invariant => True,
Aspect_Output => True,
Aspect_Pre => True,
Aspect_Predicate => True,
Aspect_Post => True,
Aspect_Read => True,
Aspect_Write => 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_Annotate => 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_Extensions_Visible => True,
Aspect_Favor_Top_Level => True,
Aspect_Ghost => 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_Suppress_Initialization => True,
Aspect_Thread_Local_Storage => 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_Annotate => False,
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_Annotate => 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_Initial_Condition => Optional_Expression,
Aspect_Default_Iterator => Name,
Aspect_Default_Storage_Pool => Expression,
Aspect_Default_Value => Expression,
Aspect_Depends => Expression,
Aspect_Dimension => Expression,
Aspect_Dimension_System => Expression,
Aspect_Dispatching_Domain => Expression,
Aspect_Dynamic_Predicate => Expression,
Aspect_Extensions_Visible => Optional_Expression,
Aspect_External_Name => Expression,
Aspect_External_Tag => Expression,
Aspect_Ghost => Optional_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_Obsolescent => Optional_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_Unimplemented => Optional_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_Annotate => Name_Annotate,
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_Component_Value => Name_Default_Component_Value,
Aspect_Default_Initial_Condition => Name_Default_Initial_Condition,
Aspect_Default_Iterator => Name_Default_Iterator,
Aspect_Default_Storage_Pool => Name_Default_Storage_Pool,
Aspect_Default_Value => Name_Default_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_Export => Name_Export,
Aspect_Extensions_Visible => Name_Extensions_Visible,
Aspect_External_Name => Name_External_Name,
Aspect_External_Tag => Name_External_Tag,
Aspect_Favor_Top_Level => Name_Favor_Top_Level,
Aspect_Ghost => Name_Ghost,
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_Elaboration_Code_All => Name_No_Elaboration_Code_All,
Aspect_No_Return => Name_No_Return,
Aspect_No_Tagged_Streams => Name_No_Tagged_Streams,
Aspect_Object_Size => Name_Object_Size,
Aspect_Obsolescent => Name_Obsolescent,
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_Suppress_Initialization => Name_Suppress_Initialization,
Aspect_Thread_Local_Storage => Name_Thread_Local_Storage,
Aspect_Synchronization => Name_Synchronization,
Aspect_Test_Case => Name_Test_Case,
Aspect_Type_Invariant => Name_Type_Invariant,
Aspect_Unchecked_Union => Name_Unchecked_Union,
Aspect_Unimplemented => Name_Unimplemented,
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).
-- SPARK 2014 aspects do not follow the general delay mechanism as they
-- act as annotations and cannot modify the attributes of their related
-- constructs. To handle forward references in such aspects, the compiler
-- delays the analysis of their respective pragmas by collecting them in
-- N_Contract nodes. The pragmas are then analyzed at the end of the
-- declarative region which contains the related construct. For details,
-- see routines Analyze_xxx_In_Decl_Part.
-- 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_Asynchronous => Always_Delay,
Aspect_Attach_Handler => Always_Delay,
Aspect_Constant_Indexing => Always_Delay,
Aspect_CPU => Always_Delay,
Aspect_Default_Iterator => Always_Delay,
Aspect_Default_Storage_Pool => Always_Delay,
Aspect_Default_Value => Always_Delay,
Aspect_Default_Component_Value => Always_Delay,
Aspect_Discard_Names => Always_Delay,
Aspect_Dispatching_Domain => Always_Delay,
Aspect_Dynamic_Predicate => Always_Delay,
Aspect_Elaborate_Body => Always_Delay,
Aspect_Export => Always_Delay,
Aspect_External_Name => Always_Delay,
Aspect_External_Tag => Always_Delay,
Aspect_Favor_Top_Level => 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_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_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_Suppress_Initialization => Always_Delay,
Aspect_Thread_Local_Storage => 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_Annotate => Never_Delay,
Aspect_Async_Readers => Never_Delay,
Aspect_Async_Writers => Never_Delay,
Aspect_Contract_Cases => Never_Delay,
Aspect_Convention => Never_Delay,
Aspect_Default_Initial_Condition => Never_Delay,
Aspect_Depends => Never_Delay,
Aspect_Dimension => Never_Delay,
Aspect_Dimension_System => Never_Delay,
Aspect_Effective_Reads => Never_Delay,
Aspect_Effective_Writes => Never_Delay,
Aspect_Extensions_Visible => Never_Delay,
Aspect_Ghost => Never_Delay,
Aspect_Global => Never_Delay,
Aspect_Initial_Condition => Never_Delay,
Aspect_Initializes => Never_Delay,
Aspect_No_Elaboration_Code_All => Never_Delay,
Aspect_No_Tagged_Streams => Never_Delay,
Aspect_Obsolescent => Never_Delay,
Aspect_Part_Of => Never_Delay,
Aspect_Refined_Depends => Never_Delay,
Aspect_Refined_Global => Never_Delay,
Aspect_Refined_Post => Never_Delay,
Aspect_Refined_State => Never_Delay,
Aspect_SPARK_Mode => Never_Delay,
Aspect_Synchronization => Never_Delay,
Aspect_Test_Case => Never_Delay,
Aspect_Unimplemented => 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;