-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
+-- 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- --
-- checks, is to attempt to detect at compilation time that a constraint
-- error will occur. If this is detected a warning or error is issued and the
-- offending expression or statement replaced with a constraint error node.
--- This always occurs whether checks are suppressed or not. Dynamic range
+-- This always occurs whether checks are suppressed or not. Dynamic range
-- checks are, of course, not inserted if checks are suppressed.
with Namet; use Namet;
-- Determines whether an expression node requires a runtime access
-- check and if so inserts the appropriate run-time check.
- procedure Apply_Accessibility_Check (N : Node_Id; Typ : Entity_Id);
+ procedure Apply_Accessibility_Check
+ (N : Node_Id;
+ Typ : Entity_Id;
+ Insert_Node : Node_Id);
-- Given a name N denoting an access parameter, emits a run-time
-- accessibility check (if necessary), checking that the level of
-- the object denoted by the access parameter is not deeper than the
-- level of the type Typ. Program_Error is raised if the check fails.
+ -- Insert_Node indicates the node where the check should be inserted.
procedure Apply_Address_Clause_Check (E : Entity_Id; N : Node_Id);
-- E is the entity for an object which has an address clause. If checks
Typ : Entity_Id;
No_Sliding : Boolean := False);
-- Top-level procedure, calls all the others depending on the class of Typ.
- -- Checks that expression N verifies the constraint of type Typ. No_Sliding
- -- is only relevant for constrained array types, id set to true, it
- -- checks that indexes are in range.
+ -- Checks that expression N satisfies the constraint of type Typ.
+ -- No_Sliding is only relevant for constrained array types, if set to True,
+ -- it checks that indexes are in range.
procedure Apply_Discriminant_Check
(N : Node_Id;
-- to make sure that the universal result is in range.
procedure Determine_Range
- (N : Node_Id;
- OK : out Boolean;
- Lo : out Uint;
- Hi : out Uint);
+ (N : Node_Id;
+ OK : out Boolean;
+ Lo : out Uint;
+ Hi : out Uint;
+ Assume_Valid : Boolean := False);
-- N is a node for a subexpression. If N is of a discrete type with no
-- error indications, and no other peculiarities (e.g. missing type
-- fields), then OK is True on return, and Lo and Hi are set to a
-- type, or some kind of error condition is detected, then OK is False on
-- exit, and Lo/Hi are set to No_Uint. Thus the significance of OK being
-- False on return is that no useful information is available on the range
- -- of the expression.
+ -- of the expression. Assume_Valid determines whether the processing is
+ -- allowed to assume that values are in range of their subtypes. If it is
+ -- set to True, then this assumption is valid, if False, then processing
+ -- is done using base types to allow invalid values.
procedure Install_Null_Excluding_Check (N : Node_Id);
-- Determines whether an access node requires a runtime access check and
-- Range checks are controlled by the Do_Range_Check flag. The front end
-- is responsible for setting this flag in relevant nodes. Originally
-- the back end generated all corresponding range checks. But later on
- -- we decided to generate all range checks in the front end. We are now
+ -- we decided to generate many range checks in the front end. We are now
-- in the transitional phase where some of these checks are still done
- -- by the back end, but many are done by the front end.
+ -- by the back end, but many are done by the front end. It is possible
+ -- that in the future we might move all the checks to the front end. The
+ -- main remaining back end checks are for subscript checking.
-- Overflow checks are similarly controlled by the Do_Overflow_Check flag.
- -- The difference here is that if Backend_Overflow_Checks is is
+ -- The difference here is that if back end overflow checks are inactive
-- (Backend_Overflow_Checks_On_Target set False), then the actual overflow
-- checks are generated by the front end, but if back end overflow checks
-- are active (Backend_Overflow_Checks_On_Target set True), then the back
-- First this routine determines if an overflow check is needed by doing
-- an appropriate range check. If a check is not needed, then the call
-- has no effect. If a check is needed then this routine sets the flag
- -- Set Do_Overflow_Check in node N to True, unless it can be determined
- -- that the check is not needed. The only condition under which this is
- -- the case is if there was an identical check earlier on.
+ -- Do_Overflow_Check in node N to True, unless it can be determined that
+ -- the check is not needed. The only condition under which this is the
+ -- case is if there was an identical check earlier on.
procedure Enable_Range_Check (N : Node_Id);
-- Set Do_Range_Check flag in node N True, unless it can be determined
-- Some of the earlier processing for checks results in temporarily setting
-- the Do_Range_Check flag rather than actually generating checks. Now we
-- are moving the generation of such checks into the front end for reasons
- -- of efficiency and simplicity (there were difficutlies in handling this
+ -- of efficiency and simplicity (there were difficulties in handling this
-- in the back end when side effects were present in the expressions being
-- checked).
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