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Diffstat (limited to 'gcc-4.4.0/gcc/ada/restrict.ads')
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diff --git a/gcc-4.4.0/gcc/ada/restrict.ads b/gcc-4.4.0/gcc/ada/restrict.ads new file mode 100644 index 000000000..2553e0444 --- /dev/null +++ b/gcc-4.4.0/gcc/ada/restrict.ads @@ -0,0 +1,334 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- R E S T R I C T -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2008, 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. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING3. If not, go to -- +-- http://www.gnu.org/licenses for a complete copy of the license. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package deals with the implementation of the Restrictions pragma + +with Namet; use Namet; +with Rident; use Rident; +with Table; +with Types; use Types; +with Uintp; use Uintp; + +package Restrict is + + Restrictions : Restrictions_Info := No_Restrictions; + -- This variable records restrictions found in any units in the main + -- extended unit, and in the case of restrictions checked for partition + -- consistency, restrictions found in any with'ed units, parent specs + -- etc., since we may as well check as much as we can at compile time. + -- These variables should not be referenced directly by clients. Instead + -- use Check_Restrictions to record a violation of a restriction, and + -- Restriction_Active to test if a given restriction is active. + + Restrictions_Loc : array (All_Restrictions) of Source_Ptr := + (others => No_Location); + -- Locations of Restrictions pragmas for error message purposes. + -- Valid only if corresponding entry in Restrictions is set. A value + -- of No_Location is used for implicit restrictions set by another + -- pragma, and a value of System_Location is used for restrictions + -- set from package Standard by the processing in Targparm. + + Restriction_Profile_Name : array (All_Restrictions) of Profile_Name; + -- Entries in this array are valid only if the corresponding restriction + -- in Restrictions set. The value is the corresponding profile name if the + -- restriction was set by a Profile or Profile_Warnings pragma. The value + -- is No_Profile in all other cases. + + Main_Restrictions : Restrictions_Info := No_Restrictions; + -- This variable records only restrictions found in any units of the + -- main extended unit. These are the variables used for ali file output, + -- since we want the binder to be able to accurately diagnose inter-unit + -- restriction violations. + + Restriction_Warnings : Rident.Restriction_Flags; + -- If one of these flags is set, then it means that violation of the + -- corresponding restriction results only in a warning message, not + -- in an error message, and the restriction is not otherwise enforced. + -- Note that the flags in Restrictions are set to indicate that the + -- restriction is set in this case, but Main_Restrictions is never + -- set if Restriction_Warnings is set, so this does not look like a + -- restriction to the binder. + + type Save_Cunit_Boolean_Restrictions is private; + -- Type used for saving and restoring compilation unit restrictions. + -- See Cunit_Boolean_Restrictions_[Save|Restore] subprograms. + + -- The following declarations establish a mapping between restriction + -- identifiers, and the names of corresponding restriction library units. + + type Unit_Entry is record + Res_Id : Restriction_Id; + Filenm : String (1 .. 8); + end record; + + Unit_Array : constant array (Positive range <>) of Unit_Entry := ( + (No_Asynchronous_Control, "a-astaco"), + (No_Calendar, "a-calend"), + (No_Calendar, "calendar"), + (No_Delay, "a-calend"), + (No_Delay, "calendar"), + (No_Dynamic_Priorities, "a-dynpri"), + (No_Finalization, "a-finali"), + (No_IO, "a-direio"), + (No_IO, "directio"), + (No_IO, "a-sequio"), + (No_IO, "sequenio"), + (No_IO, "a-ststio"), + (No_IO, "a-textio"), + (No_IO, "text_io "), + (No_IO, "a-witeio"), + (No_Task_Attributes_Package, "a-tasatt"), + (No_Unchecked_Conversion, "a-unccon"), + (No_Unchecked_Conversion, "unchconv"), + (No_Unchecked_Deallocation, "a-uncdea"), + (No_Unchecked_Deallocation, "unchdeal")); + + -- The following map has True for all GNAT pragmas. It is used to + -- implement pragma Restrictions (No_Implementation_Restrictions) + -- (which is why this restriction itself is excluded from the list). + + Implementation_Restriction : array (All_Restrictions) of Boolean := + (Simple_Barriers => True, + No_Asynchronous_Control => True, + No_Calendar => True, + No_Dispatching_Calls => True, + No_Dynamic_Attachment => True, + No_Elaboration_Code => True, + No_Enumeration_Maps => True, + No_Entry_Calls_In_Elaboration_Code => True, + No_Entry_Queue => True, + No_Exception_Handlers => True, + No_Exception_Registration => True, + No_Implementation_Attributes => True, + No_Implementation_Pragmas => True, + No_Implicit_Conditionals => True, + No_Implicit_Dynamic_Code => True, + No_Implicit_Loops => True, + No_Local_Protected_Objects => True, + No_Protected_Type_Allocators => True, + No_Relative_Delay => True, + No_Requeue_Statements => True, + No_Secondary_Stack => True, + No_Select_Statements => True, + No_Standard_Storage_Pools => True, + No_Streams => True, + No_Task_Attributes_Package => True, + No_Task_Termination => True, + No_Unchecked_Conversion => True, + No_Unchecked_Deallocation => True, + No_Wide_Characters => True, + Static_Priorities => True, + Static_Storage_Size => True, + others => False); + + -- The following table records entries made by Restrictions pragmas + -- that specify a parameter for No_Dependence. Each such pragma makes + -- an entry in this table. + + -- Note: we have chosen to implement this restriction in the "syntactic" + -- form, where we do not check that the named package is a language defined + -- package, but instead we allow arbitrary package names. The discussion of + -- this issue is not complete in the ARG, but the sense seems to be leaning + -- in this direction, which makes more sense to us, since it is much more + -- useful, and much easier to implement. + + type ND_Entry is record + Unit : Node_Id; + -- The unit parameter from the No_Dependence pragma + + Warn : Boolean; + -- True if from Restriction_Warnings, False if from Restrictions + + Profile : Profile_Name; + -- Set to name of profile from which No_Dependence entry came, or to + -- No_Profile if a pragma Restriction set the No_Dependence entry. + end record; + + package No_Dependence is new Table.Table ( + Table_Component_Type => ND_Entry, + Table_Index_Type => Int, + Table_Low_Bound => 0, + Table_Initial => 200, + Table_Increment => 200, + Table_Name => "Name_No_Dependence"); + + ----------------- + -- Subprograms -- + ----------------- + + function Abort_Allowed return Boolean; + pragma Inline (Abort_Allowed); + -- Tests to see if abort is allowed by the current restrictions settings. + -- For abort to be allowed, either No_Abort_Statements must be False, + -- or Max_Asynchronous_Select_Nesting must be non-zero. + + procedure Check_Compiler_Unit (N : Node_Id); + -- If unit N is in a unit that has a pragma Compiler_Unit, then a message + -- is posted on node N noting use of a construct that is not permitted in + -- the compiler. + + procedure Check_Restricted_Unit (U : Unit_Name_Type; N : Node_Id); + -- Checks if loading of unit U is prohibited by the setting of some + -- restriction (e.g. No_IO restricts the loading of unit Ada.Text_IO). + -- If a restriction exists post error message at the given node. + + procedure Check_Restriction + (R : Restriction_Id; + N : Node_Id; + V : Uint := Uint_Minus_1); + -- Checks that the given restriction is not set, and if it is set, an + -- appropriate message is posted on the given node. Also records the + -- violation in the appropriate internal arrays. Note that it is mandatory + -- to always use this routine to check if a restriction is violated. Such + -- checks must never be done directly by the caller, since otherwise + -- violations in the absence of restrictions are not properly recorded. The + -- value of V is relevant only for parameter restrictions, and in this case + -- indicates the exact count for the violation. If the exact count is not + -- known, V is left at its default of -1 which indicates an unknown count. + + procedure Check_Restriction_No_Dependence (U : Node_Id; Err : Node_Id); + -- Called when a dependence on a unit is created (either implicitly, or by + -- an explicit WITH clause). U is a node for the unit involved, and Err + -- is the node to which an error will be attached if necessary. + + procedure Check_Elaboration_Code_Allowed (N : Node_Id); + -- Tests to see if elaboration code is allowed by the current restrictions + -- settings. This function is called by Gigi when it needs to define + -- an elaboration routine. If elaboration code is not allowed, an error + -- message is posted on the node given as argument. + + procedure Check_Implicit_Dynamic_Code_Allowed (N : Node_Id); + -- Tests to see if dynamic code generation (dynamically generated + -- trampolines, in particular) is allowed by the current restrictions + -- settings. This function is called by Gigi when it needs to generate code + -- that generates a trampoline. If not allowed, an error message is posted + -- on the node given as argument. + + procedure Check_No_Implicit_Heap_Alloc (N : Node_Id); + -- Equivalent to Check_Restriction (No_Implicit_Heap_Allocations, N). + -- Provided for easy use by back end, which has to check this restriction. + + function Cunit_Boolean_Restrictions_Save + return Save_Cunit_Boolean_Restrictions; + -- This function saves the compilation unit restriction settings, and + -- resets them to False. This is used e.g. when compiling a with'ed + -- unit to avoid incorrectly propagating restrictions. Note that it + -- would not be wrong to also save and reset the partition restrictions, + -- since the binder would catch inconsistencies, but actually it is a + -- good thing to acquire restrictions from with'ed units if they are + -- required to be partition wide, because it allows the restriction + -- violation message to be given at compile time instead of link time. + + procedure Cunit_Boolean_Restrictions_Restore + (R : Save_Cunit_Boolean_Restrictions); + -- This is the corresponding restore procedure to restore restrictions + -- previously saved by Cunit_Boolean_Restrictions_Save. + + function Get_Restriction_Id + (N : Name_Id) return Restriction_Id; + -- Given an identifier name, determines if it is a valid restriction + -- identifier, and if so returns the corresponding Restriction_Id + -- value, otherwise returns Not_A_Restriction_Id. + + function No_Exception_Handlers_Set return Boolean; + -- Test to see if current restrictions settings specify that no exception + -- handlers are present. This function is called by Gigi when it needs to + -- expand an AT END clean up identifier with no exception handler. True + -- will be returned if the configurable run-time is activated, and either + -- of the restrictions No_Exception_Handlers or No_Exception_Propagation is + -- set. In the latter case, the source may contain handlers but they either + -- get converted using the local goto transformation or deleted. + + function No_Exception_Propagation_Active return Boolean; + -- Test to see if current restrictions settings specify that no + -- exception propagation is activated. + + function Process_Restriction_Synonyms (N : Node_Id) return Name_Id; + -- Id is a node whose Chars field contains the name of a restriction. + -- If it is one of synonyms that we allow for historical purposes (for + -- list see System.Rident), then the proper official name is returned. + -- Otherwise the Chars field of the argument is returned unchanged. + + function Restriction_Active (R : All_Restrictions) return Boolean; + pragma Inline (Restriction_Active); + -- Determines if a given restriction is active. This call should only be + -- used where the compiled code depends on whether the restriction is + -- active. Always use Check_Restriction to record a violation. Note that + -- this returns False if we only have a Restriction_Warnings set, since + -- restriction warnings should never affect generated code. + + function Restricted_Profile return Boolean; + -- Tests if set of restrictions corresponding to Profile (Restricted) is + -- currently in effect (set by pragma Profile, or by an appropriate set + -- of individual Restrictions pragmas). Returns True only if all the + -- required restrictions are set. + + procedure Set_Profile_Restrictions + (P : Profile_Name; + N : Node_Id; + Warn : Boolean); + -- Sets the set of restrictions associated with the given profile name. N + -- is the node of the construct to which error messages are to be attached + -- as required. Warn is set True for the case of Profile_Warnings where the + -- restrictions are set as warnings rather than legality requirements, and + -- is also True for Profile if the Treat_Restrictions_As_Warnings flag is + -- set. It is false for Profile if this flag is not set. + + procedure Set_Restriction + (R : All_Boolean_Restrictions; + N : Node_Id); + -- N is a node (typically a pragma node) that has the effect of setting + -- Boolean restriction R. The restriction is set in Restrictions, and + -- also in Main_Restrictions if this is the main unit. + + procedure Set_Restriction + (R : All_Parameter_Restrictions; + N : Node_Id; + V : Integer); + -- Similar to the above, except that this is used for the case of a + -- parameter restriction, and the corresponding value V is given. + + procedure Set_Restriction_No_Dependence + (Unit : Node_Id; + Warn : Boolean; + Profile : Profile_Name := No_Profile); + -- Sets given No_Dependence restriction in table if not there already. + -- Warn is True if from Restriction_Warnings, or for Restrictions if flag + -- Treat_Restrictions_As_Warnings is set. False if from Restrictions and + -- this flag is not set. Profile is set to a non-default value if the + -- No_Dependence restriction comes from a Profile pragma. + + function Tasking_Allowed return Boolean; + pragma Inline (Tasking_Allowed); + -- Tests if tasking operations are allowed by the current restrictions + -- settings. For tasking to be allowed Max_Tasks must be non-zero. + +private + type Save_Cunit_Boolean_Restrictions is + array (Cunit_Boolean_Restrictions) of Boolean; + -- Type used for saving and restoring compilation unit restrictions. + -- See Compilation_Unit_Restrictions_[Save|Restore] subprograms. + +end Restrict; |