* Makefile.in:

	(GNAT_ADA_OBJS): add g-crc32.o, a-tags.o, a-stream.o
	(GNATBIND_OBJS): add g-crc32.o, a-tags.o, a-stream.o
	(GNATLS_RTL_OBJS): add g-crc32.o
	(GNATMAKE_RTL_OBJS): add g-crc32.o

	* ali-util.adb:
	(CRC_Match): new function.
	(Get_File_Checksum): renamed Get_File_CRC. Use the GNAT.CRC32 unit
	instead of the previous simple checksum algorithm.
	(Time_Stamp_Mismatch): use CRC_Match for comparison.
	(Set_Source_Table): idem.

	* ali-util.ads:
	(Get_File_Checksum): renamed Get_File_CRC as now we compute CRC
	instead of simple checksum.
	(CRC_Match): new function.
	(CRC_Error): new constant.

	* ali.adb (Scan_ALI): rename variable Chk to CRC as we are handling
	a CRC now and not a simple checksum. A CRC uses lower-case hex
	letters, fixes ambiguity in parsing.

	* ali.ads (Sdep_Record.Checksum): renamed Sdep_Record.CRC as this
	is what this variable will store.

	* bcheck.adb: Change reference to chechsum in comments by CRC.
	(Check_Consistency): Rename Get_File_Checksum to Get_File_CRC.
	rename All_Checksum_Match to All_CRC_Match. Change due to API
	renaming since now GNAT does not use a simple checksum but a
	CRC using GNAT.CRC32.

	* gnatls.adb: Rename Checksum to CRC in many places, we use a CRC
	now and not anymore a simple checksum.

	* lib-load.adb: Use Source_CRC instead of Source_Checksum in many
	places.

	* lib-writ.adb (Write_ALI): Use Source_CRC instead of Source_Checksum.

	* scans.adb:
	(Restore_Scan_State): rename Checksum to CRC.
	(Save_Scan_State): idem.

	* scans.ads:
	With GNAT.CRC32.
	(Checksum): rename to CRC.
	(Saved_Scan_State): Save_Checksum field renamed to Save_CRC

	* scn-nlit.adb: Rename many Accumulate_Checksum to Update (from
	GNAT.CRC32).  Update copyright notice.

	* scn-slit.adb: Rename many Accumulate_Checksum to Update (from
	GNAT.CRC32).  Update copyright notice.

	* scn.adb:
	(Accumulate_Checksum): removed.
	(Update): new procedure. Add a wide-character into the CRC.

	* sinput-l.adb:
	(Complete_Source_File_Entry): use CRC32 instead of simple checksum.
	(Load_File): fix initialization of S (change Source_Checksum to
	Source_CRC)

	* sinput-p.adb (Load_Project_File): rename Source_Checksum to
	Source_CRC in S initialization.

	* sinput.adb (Source_Checksum): renamed to Source_CRC.

	* sinput.ads (Source_Checksum): renamed to Source_CRC.
	Update comments for the CRC.

	* types.adb (Hex): Use lowercase for the letter part.

	* types.ads (Get_Hex_String): Returns the hexadecimal representation
	for a word. This is currently used only for CRC. In previous version,
	the checksum was using a representation with all letter being
	upper-case. With the new implementation (using CRC) we do not remove
	the 32th bit of the CRC, so we can have an upper-case starting letter
	in the CRC. This is not possible to parse in Scan_ALI (ali.adb).
	It is ambigous since the CRC was optional and could be followed by
	options like EB, EE. So now this routines uses lower-case letter for
	the hexadecimal representation. Strange enough only lower case letters
	where checked in Scan_ALI (even if this was not a possible case).

	* gnatvsn.ads (Library_Version): changed to 3.15a.

	* s-crc32.ads: Initial version from GNAT.CRC32. This is the version
	for the compiler.

	* s-crc32.adb: Initial version from GNAT.CRC32. This is the version
	for the compiler.

	* ali-util.adb: Redo previous change to avoid using word CRC everywhere
	Add 2001 to copyright notice
	(Accumulate_Checksum): Modify to use System.CRC32.

	* ali-util.ads: Redo changes of previous revision to continue to use
	the word Checksum. Add 2001 to copyright notice.

	* ali.adb: Undo some of previous changes, not needed.
	Keep the change for lower case letters in the checksum.

	* ali.ads: Undo previous change not needed.

	* bcheck.adb: Undo most of previous change, not needed.
	But do use Checksums_Match for checksum comparison.

	* gnatls.adb: Undo most of previous change, not needed.
	But do use Checksums_Match for comparing checksums.

	* lib-load.adb: Undo previous change, not needed.

	* lib-writ.adb: Undo previous change, not needed.

	* lib-writ.ads: Document that checksums use lower case,
	not upper case letters.

	* scans.adb: Undo previous change, not needed

	* scans.ads: Undo previous change, not needed.

	* scn-nlit.adb: Undo previous changes, not needed.

	* scn-slit.adb: Undo previous change, not needed.  Fix header format.

	* scn.adb:
	(Accumulate_Checksum): Use System.CRC32.
	(Initialize_Checksum): New procedure.
	Remove other changes of previous revision.

	* sinput-p.adb: Undo previous change, not needed.

	* sinput.adb: Undo previous change, not needed.

	* sinput-l.adb: Undo previous change, not needed.

	* sinput.ads: Undo previous change, not needed.  Keep only comment
	on new checksum algorithm

	* Makefile.in: Add s-crc32 as needed, remove g-crc32.
	Also remove a-tags and a-stream from GNAT sources.

	* ali.adb (Scan_ALI): fix typo introduce in latest check-in.

	* Makefile.in (GNATRTL_NONTASKING_OBJS): Add g-crc32.o.

From-SVN: r46206

1 files changed, 20 insertions, 12 deletions

diff --git a/gcc/ada/scn.adb b/gcc/ada/scn.adb
index 146314d..af6668a 100644
--- a/gcc/ada/scn.adb
+++ b/gcc/ada/scn.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---                            $Revision: 1.111 $
+--                            $Revision$
 --                                                                          --
 --          Copyright (C) 1992-2001 Free Software Foundation, Inc.          --
 --                                                                          --
@@ -39,6 +39,7 @@ with Snames;   use Snames;
 with Style;
 with Widechar; use Widechar;
 
+with System.CRC32;
 with System.WCh_Con; use System.WCh_Con;
 
 package body Scn is
@@ -73,6 +74,10 @@ package body Scn is
    --  are scanned. We use the character code rather than the ASCII characters
    --  so that the checksum is independent of wide character encoding method.
 
+   procedure Initialize_Checksum;
+   pragma Inline (Initialize_Checksum);
+   --  Initialize checksum value
+
    procedure Check_End_Of_Line;
    --  Called when end of line encountered. Checks that line is not
    --  too long, and that other style checks for the end of line are met.
@@ -135,20 +140,13 @@ package body Scn is
 
    procedure Accumulate_Checksum (C : Character) is
    begin
-      Checksum := Checksum + Checksum + Character'Pos (C);
-
-      if Checksum > 16#8000_0000# then
-         Checksum := (Checksum + 1) and 16#7FFF_FFFF#;
-      end if;
+      System.CRC32.Update (System.CRC32.CRC32 (Checksum), C);
    end Accumulate_Checksum;
 
    procedure Accumulate_Checksum (C : Char_Code) is
    begin
-      Checksum := Checksum + Checksum + Char_Code'Pos (C);
-
-      if Checksum > 16#8000_0000# then
-         Checksum := (Checksum + 1) and 16#7FFF_FFFF#;
-      end if;
+      Accumulate_Checksum (Character'Val (C / 256));
+      Accumulate_Checksum (Character'Val (C mod 256));
    end Accumulate_Checksum;
 
    -----------------------
@@ -367,6 +365,15 @@ package body Scn is
       Error_Msg_S ("two consecutive underlines not permitted");
    end Error_No_Double_Underline;
 
+   -------------------------
+   -- Initialize_Checksum --
+   -------------------------
+
+   procedure Initialize_Checksum is
+   begin
+      System.CRC32.Initialize (System.CRC32.CRC32 (Checksum));
+   end Initialize_Checksum;
+
    ------------------------
    -- Initialize_Scanner --
    ------------------------
@@ -465,7 +472,8 @@ package body Scn is
       Token_Name                := No_Name;
       Start_Column              := Set_Start_Column;
       First_Non_Blank_Location  := Scan_Ptr;
-      Checksum                  := 0;
+
+      Initialize_Checksum;
 
       --  Set default for Comes_From_Source. All nodes built now until we
       --  reenter the analyzer will have Comes_From_Source set to True