------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- R E S T R I C T -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2003 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 2, 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 COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- 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 Rident; with Types; use Types; with Uintp; use Uintp; package Restrict is type Restriction_Id is new Rident.Restriction_Id; -- The type Restriction_Id defines the set of restriction identifiers, -- which take no parameter (i.e. they are either present or not present). -- The actual definition is in the separate package Rident, so that -- it can easily be accessed by the binder without dragging in lots -- of stuff. subtype All_Restrictions is Restriction_Id range Restriction_Id (Rident.All_Restrictions'First) .. Restriction_Id (Rident.All_Restrictions'Last); -- All restriction identifiers subtype Partition_Restrictions is Restriction_Id range Restriction_Id (Rident.Partition_Restrictions'First) .. Restriction_Id (Rident.Partition_Restrictions'Last); -- Range of restriction identifiers that are checked by the binder subtype Compilation_Unit_Restrictions is Restriction_Id range Restriction_Id (Rident.Compilation_Unit_Restrictions'First) .. Restriction_Id (Rident.Compilation_Unit_Restrictions'Last); -- Range of restriction identifiers not checked by binder type Restriction_Parameter_Id is new Rident.Restriction_Parameter_Id; -- The type Restriction_Parameter_Id records cases where a parameter is -- present in the corresponding pragma. The actual definition is in the -- separate package Rident for consistency. type Restrictions_Flags is array (Restriction_Id) of Boolean; -- Type used for arrays indexed by Restriction_Id. Restrictions : Restrictions_Flags := (others => False); -- Corresponding entry is False if restriction is not active, and -- True if the restriction is active, i.e. if a pragma Restrictions -- has been seen anywhere. Note that we are happy to pick up any -- restrictions pragmas in with'ed units, since we are required to -- be consistent at link time, and we might as well find the error -- at compile time. Clients must NOT use this array for checking to -- see if a restriction is violated, instead it is required that the -- Check_Restriction subprograms be used for this purpose. The only -- legitimate direct use of this array is when the code is modified -- as a result of the restriction in some way. Restrictions_Loc : array (Restriction_Id) 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. Main_Restrictions : Restrictions_Flags := (others => False); -- This variable saves the cumulative restrictions in effect compiling -- any unit that is part of the extended main unit (i.e. the compiled -- unit, its spec if any, and its subunits if any). The reason we keep -- track of this is for the information that goes to the binder about -- restrictions that are set. The binder will identify a unit that has -- a restrictions pragma for error message purposes, and we do not want -- to pick up a restrictions pragma in a with'ed unit for this purpose. Violations : Restrictions_Flags := (others => False); -- Corresponding entry is False if the restriction has not been -- violated in the current main unit, and True if it has been violated. Restriction_Warnings : Restrictions_Flags := (others => False); -- 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. Restriction_Parameters : array (Restriction_Parameter_Id) of Uint := (others => No_Uint); -- This array indicates the setting of restriction parameter identifier -- values. All values are initially set to No_Uint indicating that the -- parameter is not set, and are set to the appropriate non-negative -- value if a Restrictions pragma specifies the corresponding -- restriction parameter identifier with an appropriate value. Restriction_Parameters_Loc : array (Restriction_Parameter_Id) of Source_Ptr; -- Locations of Restrictions pragmas for error message purposes. -- Valid only if corresponding entry in Restriction_Parameters is -- set to a value other than No_Uint. type Unit_Entry is record Res_Id : Restriction_Id; Filenm : String (1 .. 8); end record; type Unit_Array_Type is array (Positive range <>) of Unit_Entry; Unit_Array : constant Unit_Array_Type := ( (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, "a-tasatt"), (No_Streams, "a-stream"), (No_Unchecked_Conversion, "a-unccon"), (No_Unchecked_Conversion, "unchconv"), (No_Unchecked_Deallocation, "a-uncdea"), (No_Unchecked_Deallocation, "unchdeal")); -- This array defines the mapping between restriction identifiers and -- predefined language files containing units for which the identifier -- forbids semantic dependence. type Save_Compilation_Unit_Restrictions is private; -- Type used for saving and restoring compilation unit restrictions. -- See Compilation_Unit_Restrictions_[Save|Restore] subprograms. -- 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 : Restrictions_Flags := (Boolean_Entry_Barriers => True, No_Calendar => True, No_Dynamic_Interrupts => 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_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 => True, No_Secondary_Stack => True, No_Select_Statements => True, No_Standard_Storage_Pools => True, No_Streams => True, No_Task_Attributes => True, No_Task_Termination => True, No_Wide_Characters => True, Static_Priorities => True, Static_Storage_Size => True, No_Implementation_Attributes => True, No_Implementation_Pragmas => True, No_Elaboration_Code => True, others => False); ----------------- -- 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_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); -- 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 violations array. 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 -- they are not properly recorded in the violations array. procedure Check_Restriction (R : Restriction_Parameter_Id; V : Uint; N : Node_Id); -- Checks that the count in V does not exceed the maximum value of the -- restriction parameter value corresponding to the given restriction -- parameter identifier (if it has been set). If the count in V exceeds -- the maximum, then post an error message on node N. We use this call -- when we can tell the maximum usage at compile time. In other words, -- we guarantee that if a call is made to this routine, then the front -- end will make all necessary calls for the restriction parameter R -- to ensure that we really know the maximum value used anywhere. procedure Check_Restriction (R : Restriction_Parameter_Id; N : Node_Id); -- Check that the maximum value of the restriction parameter corresponding -- to the given restriction parameter identifier is not set to zero. If -- it has been set to zero, post an error message on node N. We use this -- call in cases where we can tell at compile time that the count must be -- at least one, but we can't tell anything more. 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_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 Compilation_Unit_Restrictions_Save return Save_Compilation_Unit_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 Compilation_Unit_Restrictions_Restore (R : Save_Compilation_Unit_Restrictions); -- This is the corresponding restore procedure to restore restrictions -- previously saved by Compilation_Unit_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 Get_Restriction_Parameter_Id (N : Name_Id) return Restriction_Parameter_Id; -- Given an identifier name, determines if it is a valid restriction -- parameter identifier, and if so returns the corresponding -- Restriction_Parameter_Id value, otherwise returns -- Not_A_Restriction_Parameter_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. function Restricted_Profile return Boolean; -- Tests to see if tasking operations follow the GNAT restricted run time -- profile. procedure Set_Ravenscar (N : Node_Id); -- Enables the set of restrictions for Ravenscar. N is the corresponding -- pragma node, which is used for error messages on any constructs that -- violate the profile. procedure Set_Restricted_Profile (N : Node_Id); -- Enables the set of restrictions for pragma Restricted_Run_Time. N is -- the corresponding pragma node, which is used for error messages on -- constructs that violate the profile. function Tasking_Allowed return Boolean; pragma Inline (Tasking_Allowed); -- Tests to see if tasking operations are allowed by the current -- restrictions settings. For tasking to be allowed Max_Tasks must -- be non-zero. private type Save_Compilation_Unit_Restrictions is array (Compilation_Unit_Restrictions) of Boolean; -- Type used for saving and restoring compilation unit restrictions. -- See Compilation_Unit_Restrictions_[Save|Restore] subprograms. end Restrict;