Re: [gnat] reuse of ASTs already constructed

["oliver dot kellogg at t-online dot de" <oliver dot kellogg at t-online dot de>]

I am finally finding some some time to continue this work,
having left off with
  http://gcc.gnu.org/ml/gcc/2009-08/msg00475.html :

> [...]
> There are two problems right now:
> 
> 1) Mixing of Ada.Text_IO and Text_IO as described at
>    http://gcc.gnu.org/ml/gcc-help/2009-08/msg00113.html

The solution to this one turned out to be quite simple, see attached patch.
Sem_Ch12.Analyze_Package_Instantiation calls Rtsfind.Text_IO_Kludge,
and the latter contains:

          if Chrs in Text_IO_Package_Name then
             for U in Main_Unit .. Last_Unit loop
                Get_Name_String (Unit_File_Name (U));
                ...
On compiling the second file, Main_Unit is not 0 but some larger value.
The existing node for Text_IO was not being found because it is at an
index smaller than the current Main_Unit. The solution was to start the
loop at index 0.

I will now start looking into the second problem,

> 2) The 'X' lines in the ALI files are not what they should be.
> This is due to the fact that Lib.Xref.Generate_(Definition|Reference) is
> called during semantic analysis. However, when I discover that a
> tree was already built for a main unit by a previous compilation,
> Sem is not redone for that tree. Depending on whether
> Lib.Xref.Initialize is called per-job or per-file, this leads to either
> too much or too little cross ref info.

By the way, I am currently using trunk r152433 (4.5.0 pre-release) and
moving forward to the 4.5.0 release.
When that is done: Should I continue on trunk or switch to the
gcc-4_5-branch ?

Thanks,

Oliver

Index: rtsfind.adb
===================================================================
--- rtsfind.adb	(revision 152433)
+++ rtsfind.adb	(working copy)
@@ -1406,7 +1406,7 @@
       --  or [Wide_]Wide_Text_IO already loaded, then load the proper child.
 
       if Chrs in Text_IO_Package_Name then
-         for U in Main_Unit .. Last_Unit loop
+         for U in 0 .. Last_Unit loop
             Get_Name_String (Unit_File_Name (U));
 
             if Name_Len = 12 then