Uninitialized section index internal error on Tru64 5.1

[Joel Brobecker <brobecker at act-europe dot fr>]

Hi,

While working on gdb on Tru64 5.1, we noticed the following internal
error sometimes happening at the begining of a gdb session:

> gdb/mdebugread.c:2448: gdb-internal-error: Section index is uninitialized
>
> An internal GDB error was detected.  This may make further
> debugging unreliable.  Continue this debugging session? (y or n) n

To reproduce the problem, simply compile the following C program:

mach.c:
<<
int
main (void)
{
   return 0;
};
>>

Make sure libmach is linked in when building the program:
% gcc -o mach mach.c -lmach

After for investigation, I found that gdb was looking for a symbol in
the .bss section of libmach.so, but there is none (which explains why
the section index is not initialized). Instead, there is a .sbss
section, where the symbol is localized.

I modified default_symfile_offsets () to use the .sbss section if the
.bss one does not exist. In that change, I am assuming that a bss and a
sbss section are mutually exclusive.

This change has been integrated in ACT's version of gdb a few months
ago, and has worked well so far. I am attaching a patch that includes
this change along with the ChangeLog.

-- 
Joel

PS: Please note that I am sending this patch on behalf of ACT (Ada Core
Technologies). I haven't filed an assignment for gdb changes under my
name, but ACT has.
Index: gdb/symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.31
diff -c -3 -p -r1.31 symfile.c
*** symfile.c	2001/04/05 02:02:13	1.31
--- symfile.c	2001/05/10 19:41:39
*************** default_symfile_offsets (struct objfile 
*** 529,534 ****
--- 529,536 ----
      objfile->sect_index_data = sect->index;
  
    sect = bfd_get_section_by_name (objfile->obfd, ".bss");
+   if (!sect)
+     sect = bfd_get_section_by_name (objfile->obfd, ".sbss");
    if (sect) 
      objfile->sect_index_bss = sect->index;
  
Index: gdb/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/ChangeLog,v
retrieving revision 1.1223
diff -c -3 -p -r1.1223 ChangeLog
*** ChangeLog	2001/05/07 20:02:24	1.1223
--- ChangeLog	2001/05/10 19:41:42
***************
*** 1,3 ****
--- 1,8 ----
+ 2001-05-10  J. Brobecker <brobecker@act-europe.fr>
+ 
+         * symfile.c (default_symfile_offsets): use the .sbss section in
+         place of the .bss section when the latter does not exist.
+ 
  2001-05-07  Andrew Cagney  <ac131313@redhat.com>
  
  	* MAINTAINERS: I'm no longer actively maintaining the mn10300