opt.ads (Old_Checksums, [...]): New Boolean flags, defaulted to False.

2010-10-26  Vincent Celier  <celier@adacore.com>

	* opt.ads (Old_Checksums, Old_Old_Checksums): New Boolean flags,
	defaulted to False.
	* prj-nmsc.adb (Process_Project_Level_Array_Attributes): When
	processing attribute Toolchain_Version ("Ada"), set Opt.Old_Checksums
	and Opt.Old_Old_Checksums depending on the GNAT version.
	* scng.adb (Accumulate_Token_Checksum_Old): New procedure.
	(Accumulate_Token_Checksum_Old_Old): New procedure.
	(Scan): For keywords, when Opt.Old_Checksums is True, call one of the
	alternative procedures Accumulate_Token_Checksum_Old or
	Accumulate_Token_Checksum_Old_Old, instead of Accumulate_Token_Checksum.

From-SVN: r165959

1 files changed, 47 insertions, 0 deletions

diff --git a/gcc/ada/prj-nmsc.adb b/gcc/ada/prj-nmsc.adb
index 246d28a..e0df107 100644
--- a/gcc/ada/prj-nmsc.adb
+++ b/gcc/ada/prj-nmsc.adb
@@ -2399,6 +2399,53 @@ package body Prj.Nmsc is
                         Lang_Index.Config.Toolchain_Version :=
                           Element.Value.Value;
 
+                        --  We need a complete comment section discussing the
+                        --  need for three versions of the checksum algorithm
+                        --  and what is going on here??? Also Old and Old_Old
+                        --  are rather poor names I would say. How about
+
+                        --    Opt.Checksum_503
+                        --    Opt.Checksum_63
+
+                        --  If the Ada compiler is version 6.3 or before, then
+                        --  checksums need to be computed using the old way.
+
+                        --  Also, how about an abstraction for checking
+                        --  version numbers, something like ???
+
+                        --    if Version_Is_Before (5, 3) ....
+
+                        if Lang_Index.Name = Name_Ada then
+                           declare
+                              Vers : constant String :=
+                                       Get_Name_String (Element.Value.Value);
+                              pragma Assert (Vers'First = 1);
+
+                           begin
+                              if Vers'Length >= 8
+                                and then Vers (1 .. 5) = "GNAT "
+                                and then Vers (7) = '.'
+                                and then
+                                  (Vers (6) < '6'
+                                    or else
+                                      (Vers (6) = '6' and then Vers (8) < '4'))
+                              then
+                                 Opt.Old_Checksums := True;
+
+                                 --  If the Ada compiler is version 5.03 or
+                                 --  before, then checksums need to be computed
+                                 --  using the other old way.
+
+                                 if Vers (6) < '5'
+                                   or else (Vers (6) = '5'
+                                             and then Vers (Vers'Last) < '4')
+                                 then
+                                    Opt.Old_Old_Checksums := True;
+                                 end if;
+                              end if;
+                           end;
+                        end if;
+
                      when Name_Runtime_Library_Dir =>
 
                         --  Attribute Runtime_Library_Dir (<language>)