-- --
-- S p e c --
-- --
--- $Revision$
--- --
--- Copyright (C) 1992-2002 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2007, 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- --
+-- 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 COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
+-- 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. --
--- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
+-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This package deals with the implementation of the Restrictions pragma
-with Rident;
+with Namet; use Namet;
+with Rident; use Rident;
+with Table;
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. These cases are not checked for
- -- consistency by the binder. 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;
- -- Locations of Restrictions pragmas for error message purposes.
- -- Valid only if corresponding entry in Restrictions is set.
-
- 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_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;
+ 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 Restriction_Parameters is
- -- set to a value other than No_Uint.
+ -- 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_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;
- 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_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.
+ 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 : Restrictions_Flags :=
- (Boolean_Entry_Barriers => True,
+ Implementation_Restriction : array (All_Restrictions) of Boolean :=
+ (Simple_Barriers => True,
No_Calendar => True,
- No_Dynamic_Interrupts => True,
+ No_Dispatching_Calls => True,
+ No_Dynamic_Attachment => 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_Requeue_Statements => True,
No_Secondary_Stack => True,
No_Select_Statements => True,
No_Standard_Storage_Pools => True,
No_Streams => True,
- No_Task_Attributes => True,
+ No_Task_Attributes_Package => True,
No_Task_Termination => True,
- No_Tasking => True,
No_Wide_Characters => True,
Static_Priorities => True,
Static_Storage_Size => True,
No_Elaboration_Code => 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
+ 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);
+ 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 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;
- N : Node_Id);
- -- Checks that the given restriction parameter identifier is not set to
- -- zero. If it is set to zero, then the node N is replaced by a node
- -- that raises Storage_Error, and a warning is issued.
-
- 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.
+ -- 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 value 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
-- an elaboration routine. If elaboration code is not allowed, an error
-- message is posted on the node given as argument.
- 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.
+ 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.
- function Compilation_Unit_Restrictions_Save
- return Save_Compilation_Unit_Restrictions;
+ 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
-- 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);
+ procedure Cunit_Boolean_Restrictions_Restore
+ (R : Save_Cunit_Boolean_Restrictions);
-- This is the corresponding restore procedure to restore restrictions
- -- previously saved by Compilation_Unit_Restrictions_Save.
-
- procedure Disallow_In_No_Run_Time_Mode (Enode : Node_Id);
- -- If in No_Run_Time mode, then the construct represented by Enode is
- -- not permitted, and will be appropriately flagged.
-
- procedure Set_No_Run_Time_Mode;
- -- Set the no run time mode, and associated restriction pragmas.
+ -- previously saved by Cunit_Boolean_Restrictions_Save.
function Get_Restriction_Id
- (N : Name_Id)
- return 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 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.
+ 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 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 to see if tasking operations follow the GNAT restricted run time
- -- profile.
-
- procedure Set_Ravenscar;
- -- Sets the set of rerstrictions fro Ravenscar
-
- procedure Set_Restricted_Profile;
- -- Sets the set of restrictions for pragma Restricted_Run_Time
+ -- 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 pragms). 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.
+
+ 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);
+ -- Sets given No_Dependence restriction in table if not there already.
+ -- Warn is True if from Restriction_Warnings, False if from Restrictions.
function Tasking_Allowed return Boolean;
pragma Inline (Tasking_Allowed);
-- be non-zero.
private
- type Save_Compilation_Unit_Restrictions is
- array (Compilation_Unit_Restrictions) of Boolean;
+ 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.
OSDN Git Service
