| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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; |
