2008-08-22 Robert Dewar <dewar@adacore.com>

	* checks.adb (Determine_Range): Deal with values that might be invalid

	* opt.adb, opt.ads (Assume_No_Invalid_Values[_Config]): New configuration
	switches.

	* par-prag.adb: Dummy entry for pragma Assume_No_Invalid_Values

	* sem_prag.adb: Implement pragma Assume_No_Default_Values

	* snames.adb, snames.ads, snames.h:
	Add entries for pragma Assume_No_Invalid_Values

	* switch-c.adb: Add processing for -gnatB switch

	* usage.adb: Add entry for flag -gnatB (no bad invalid values)



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@139484 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 17 insertions, 0 deletions

diff --git a/gcc/ada/opt.ads b/gcc/ada/opt.ads
index 1e68d70d2b8..542dc2568d0 100644
--- a/gcc/ada/opt.ads
+++ b/gcc/ada/opt.ads
@@ -158,6 +158,15 @@ package Opt is
    --  GNAT
    --  Enable assertions made using pragma Assert
 
+   Assume_No_Invalid_Values : Boolean := True;
+   --  ??? true for now, enable by setting to false later
+   --  GNAT
+   --  Normallly, in accordance with (RM 13.9.1 (9-11)) the front end assumes
+   --  that values could have invalid representations, unless it can clearly
+   --  prove that the values are valid. If this switch is set (by -gnatB or by
+   --  pragma Assume_No_Invalid_Values (Off)), then the compiler assumes values
+   --  are valid and in range of their representations.
+
    Back_Annotate_Rep_Info : Boolean := False;
    --  GNAT
    --  If set True, enables back annotation of representation information
@@ -1414,6 +1423,13 @@ package Opt is
    --  mode, as possibly set by the command line switch -gnata, and possibly
    --  modified by the use of the configuration pragma Assertion_Policy.
 
+   Assume_No_Invalid_Values_Config : Boolean;
+   --  GNAT
+   --  This is the value of the configuration switch for assuming no invalid
+   --  values enabled mode mode, as possibly set by the command line switch
+   --  -gnatB, and possibly modified by the use of the configuration pragma
+   --  Assume_No_Invalid_Values.
+
    Check_Policy_List_Config : Node_Id;
    --  GNAT
    --  This points to the list of N_Pragma nodes for Check_Policy pragmas
@@ -1612,6 +1628,7 @@ private
       Ada_Version                    : Ada_Version_Type;
       Ada_Version_Explicit           : Ada_Version_Type;
       Assertions_Enabled             : Boolean;
+      Assume_No_Invalid_Values       : Boolean;
       Check_Policy_List              : Node_Id;
       Debug_Pragmas_Enabled          : Boolean;
       Dynamic_Elaboration_Checks     : Boolean;