I realize I just dumped the previous patch without explaining it,
so maybe this will help reducing the workload from Daniel,
or maybe even finding a new reviewer (yes, that's you! :) ).

In a nutshell:
In coff based targets, there is a new segfault in
parse.c:write_exp_msymbol,
at:
  if (SYMBOL_BFD_SECTION (msymbol)->flags & SEC_THREAD_LOCAL)

Easily triggered by just issuing p.ex.:
p globalvar

The problem is that minimal symbols may have a bfd_section set to
NULL at this point. (SYMBOL_BFD_SECTION (msymbol) == NULL).

This segfault doesn't happen in elf targets, because in elfread.c,
prim_record_minimal_symbol_and_info is always called with a non-NULL bfd_section*,
effectively always creating a minimal symbol with a bfd_section set.

In coffread.c, prim_record_minimal_symbol_and_info is always called with
bfd_section == NULL.

The attached patch, (functionally equivalent to the previous one,
with just a small cleanup), makes the coff reader match
the bfd_section from the coff_symbol, using the symbols' section number
and bfd_map_over_sections. This matching was already done in the
existing code, in cs_to_section, so it should be correct,
unlike the previous versions that used objfile->sections.

A few other functions are then adjusted to be able to pass bfd_section while
preserving the rest of the existing behavior.

I don't thing that the original workaround in the beginning of this thread ...:
- if (SYMBOL_BFD_SECTION (msymbol)->flags & SEC_THREAD_LOCAL)
+ if (SYMBOL_BFD_SECTION (msymbol)
+     && (SYMBOL_BFD_SECTION (msymbol)->flags & SEC_THREAD_LOCAL))

... should still be applied. Having it segfault there for other
formats and fix them accordingly would be better, than hiding
the real bug, IMHO.


Hope this helped,

Cheers,
Pedro Alves

---

2006-11-18 Pedro Alves <pedro_alves@portugalmail.pt>

* symtab.h (prim_record_minimal_symbol_and_bfd_section): Declare.
* minsyms.c (prim_record_minimal_symbol_and_bfd_section): Rename from prim_record_minimal_symbol
and add bfd_section parameter.
(prim_record_minimal_symbol): New version; wraps prim_record_minimal_symbol_and_bfd_section.
* coffread.c (cs_to_bfd_section): New function.
(cs_to_section): Use cs_to_bfd_section.
(record_minimal_symbol): Add bfd_section parameter. Call prim_record_minimal_symbol_and_bfd_section.
(coff_symtab_read): Use cs_to_bfd_section.