On Wed, 28 Oct 2009, Helge Deller wrote:
> On 10/28/2009 11:43 PM, Helge Deller wrote:
>> On 10/28/2009 11:18 PM, John David Anglin wrote:
>>>>> and whether it follows inb in its .o. From my understanding of things,
>>>>> it shouldn't be necessary to remove the unwind info for unused weak
>>>>> symbols if they aren't garbage collected. A simple testcase would
>>>>> be helpful.
>
> Attached is a testcase (t1.c and t2.c):
> t1.c contains weak function f().
> t2.c contains non-weak function f().
>
> hppa-linux-gcc -c t1.c t2.c
> hppa-linux-ld -r -o all.o t1.o t2.o
Attached is a patch for gas that seems to produce reasonable
unwind info for the testcase when all.o is linked into a final
executable. I think it will fix the linux unwind problem.
Still need to look at readelf -u on .o's.
Dave
--
J. David Anglin dave.anglin@xxxxxxxxxxxxxx
National Research Council of Canada (613) 990-0752 (FAX: 952-6602)
Index: config/tc-hppa.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-hppa.c,v
retrieving revision 1.145
diff -u -3 -p -r1.145 tc-hppa.c
--- config/tc-hppa.c 24 Jul 2009 11:45:00 -0000 1.145
+++ config/tc-hppa.c 29 Oct 2009 18:37:39 -0000
@@ -5961,13 +5961,41 @@ pa_build_unwind_subspace (struct call_in
subsegT save_subseg;
unsigned int unwind;
int reloc;
- char *p;
+ char *name, *p;
+ symbolS *symbolP;
if ((bfd_get_section_flags (stdoutput, now_seg)
& (SEC_ALLOC | SEC_LOAD | SEC_READONLY))
!= (SEC_ALLOC | SEC_LOAD | SEC_READONLY))
return;
+ /* Replace the start symbol with a local symbol that will be reduced
+ to a section offset. This avoids problems with weak functions with
+ multiple definitions, etc. */
+ name = xmalloc (strlen ("L$\001start_")
+ + strlen (S_GET_NAME (call_info->start_symbol))
+ + 1);
+ strcpy (name, "L$\001start_");
+ strcat (name, S_GET_NAME (call_info->start_symbol));
+
+ /* If we have a .procend preceded by a .exit, then the symbol will have
+ already been defined. In that case, we don't want another unwind
+ entry. */
+ symbolP = symbol_find (name);
+ if (symbolP)
+ {
+ xfree (name);
+ return;
+ }
+ else
+ {
+ symbolP = symbol_new (name, now_seg,
+ S_GET_VALUE (call_info->start_symbol), frag_now);
+ gas_assert (symbolP);
+ S_CLEAR_EXTERNAL (symbolP);
+ symbol_table_insert (symbolP);
+ }
+
reloc = R_PARISC_SEGREL32;
save_seg = now_seg;
save_subseg = now_subseg;
@@ -5993,7 +6021,7 @@ pa_build_unwind_subspace (struct call_in
/* Relocation info. for start offset of the function. */
md_number_to_chars (p, 0, 4);
fix_new_hppa (frag_now, p - frag_now->fr_literal, 4,
- call_info->start_symbol, (offsetT) 0,
+ symbolP, (offsetT) 0,
(expressionS *) NULL, 0, reloc,
e_fsel, 32, 0, 0);
