* Re: [RFC/RFA] find_pc_sect_psymtab(): symbol table not always complete
2003-11-20 0:24 ` Joel Brobecker
@ 2003-12-02 16:15 ` Daniel Jacobowitz
2004-01-17 8:13 ` Joel Brobecker
2004-02-19 19:01 ` Elena Zannoni
2 siblings, 0 replies; 7+ messages in thread
From: Daniel Jacobowitz @ 2003-12-02 16:15 UTC (permalink / raw)
To: Joel Brobecker; +Cc: gdb-patches
On Wed, Nov 19, 2003 at 04:23:59PM -0800, Joel Brobecker wrote:
> > > 2003-11-19 J. Brobecker <brobecker@gnat.com>
> > >
> > > * symtab.c (find_pc_sect_psymtab): Refine the search for the
> > > partial symtab corresponding to the given PC address, taking
> > > into account the fact that the symbol table might be incomplete.
> >
> > FWIW, this looks good to me, but I'd like another comment on the new
> > test to the effect of, the find_pc_sect_psymtab call will always return
> > the closest symbol below pc in tpst. Threw me for a moment how you
> > were just checking for the highest valued symbol.
>
> Thanks for your feedback Daniel. I agree on that a comment is useful.
> Here is a revised version of the patch. Is it better?
This looks great to me. It'll need to be approved by the symtab
maintainers.
> Index: symtab.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/symtab.c,v
> retrieving revision 1.122
> diff -u -p -r1.122 symtab.c
> --- symtab.c 8 Nov 2003 00:13:03 -0000 1.122
> +++ symtab.c 20 Nov 2003 00:21:30 -0000
> @@ -698,6 +698,8 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
> if (pc >= pst->textlow && pc < pst->texthigh)
> {
> struct partial_symtab *tpst;
> + struct partial_symtab *best_pst = pst;
> + struct partial_symbol *best_psym = NULL;
>
> /* An objfile that has its functions reordered might have
> many partial symbol tables containing the PC, but
> @@ -710,6 +712,11 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
> if (msymbol == NULL)
> return (pst);
>
> + /* The code range of partial symtabs sometimes overlap, so
> + we need to check all partial symtabs and find the one that
> + fits better for the given PC address. We select the partial
> + symtab that contains a symbol which address is closest to
> + the PC address. */
> for (tpst = pst; tpst != NULL; tpst = tpst->next)
> {
> if (pc >= tpst->textlow && pc < tpst->texthigh)
> @@ -721,9 +728,24 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
> && SYMBOL_VALUE_ADDRESS (p)
> == SYMBOL_VALUE_ADDRESS (msymbol))
> return (tpst);
> + if (p != NULL)
> + {
> + /* We found a symbol in this partial symtab which
> + matches PC, check whether it is closer than our
> + current BEST_PSYM. Since this symbol address is
> + necessarily lower or equal to PC, the symbol closer
> + to PC is the symbol which address is the highest. */
> + if (best_psym == NULL
> + || SYMBOL_VALUE_ADDRESS (p)
> + > SYMBOL_VALUE_ADDRESS (best_psym))
> + {
> + best_psym = p;
> + best_pst = tpst;
> + }
> + }
> }
> }
> - return (pst);
> + return best_pst;
> }
> }
> return (NULL);
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [RFC/RFA] find_pc_sect_psymtab(): symbol table not always complete
2003-11-20 0:24 ` Joel Brobecker
2003-12-02 16:15 ` Daniel Jacobowitz
@ 2004-01-17 8:13 ` Joel Brobecker
2004-02-19 19:01 ` Elena Zannoni
2 siblings, 0 replies; 7+ messages in thread
From: Joel Brobecker @ 2004-01-17 8:13 UTC (permalink / raw)
To: gdb-patches
On Wed, Nov 19, 2003 at 04:23:59PM -0800, Joel Brobecker wrote:
> 2003-11-19 J. Brobecker <brobecker@gnat.com>
>
> * symtab.c (find_pc_sect_psymtab): Refine the search for the
> partial symtab corresponding to the given PC address, taking
> into account the fact that the symbol table might be incomplete.
ping?
(DanielJ gave a positive feedback on this patch early december)
> Index: symtab.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/symtab.c,v
> retrieving revision 1.122
> diff -u -p -r1.122 symtab.c
> --- symtab.c 8 Nov 2003 00:13:03 -0000 1.122
> +++ symtab.c 20 Nov 2003 00:21:30 -0000
> @@ -698,6 +698,8 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
> if (pc >= pst->textlow && pc < pst->texthigh)
> {
> struct partial_symtab *tpst;
> + struct partial_symtab *best_pst = pst;
> + struct partial_symbol *best_psym = NULL;
>
> /* An objfile that has its functions reordered might have
> many partial symbol tables containing the PC, but
> @@ -710,6 +712,11 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
> if (msymbol == NULL)
> return (pst);
>
> + /* The code range of partial symtabs sometimes overlap, so
> + we need to check all partial symtabs and find the one that
> + fits better for the given PC address. We select the partial
> + symtab that contains a symbol which address is closest to
> + the PC address. */
> for (tpst = pst; tpst != NULL; tpst = tpst->next)
> {
> if (pc >= tpst->textlow && pc < tpst->texthigh)
> @@ -721,9 +728,24 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
> && SYMBOL_VALUE_ADDRESS (p)
> == SYMBOL_VALUE_ADDRESS (msymbol))
> return (tpst);
> + if (p != NULL)
> + {
> + /* We found a symbol in this partial symtab which
> + matches PC, check whether it is closer than our
> + current BEST_PSYM. Since this symbol address is
> + necessarily lower or equal to PC, the symbol closer
> + to PC is the symbol which address is the highest. */
> + if (best_psym == NULL
> + || SYMBOL_VALUE_ADDRESS (p)
> + > SYMBOL_VALUE_ADDRESS (best_psym))
> + {
> + best_psym = p;
> + best_pst = tpst;
> + }
> + }
> }
> }
> - return (pst);
> + return best_pst;
> }
> }
> return (NULL);
--
Joel
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [RFC/RFA] find_pc_sect_psymtab(): symbol table not always complete
2003-11-20 0:24 ` Joel Brobecker
2003-12-02 16:15 ` Daniel Jacobowitz
2004-01-17 8:13 ` Joel Brobecker
@ 2004-02-19 19:01 ` Elena Zannoni
2004-02-20 17:11 ` Joel Brobecker
2 siblings, 1 reply; 7+ messages in thread
From: Elena Zannoni @ 2004-02-19 19:01 UTC (permalink / raw)
To: Joel Brobecker; +Cc: gdb-patches
Joel Brobecker writes:
Joel, I committed an updated version of your patch. By updated I mean
with new/more comments. Now let's keep an eye on any apparently
unrelated breakage :-)
elena
2004-02-19 Joel Brobecker <brobecker@gnat.com>
Committed by Elena Zannoni <ezannoni@redhat.com>
* symtab.c (find_pc_sect_psymtab): Return the psymtab that
contains a symbol wich is the best, non-exact match for the given
pc. Update comments.
Index: symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.127
diff -u -p -r1.127 symtab.c
--- symtab.c 17 Feb 2004 15:21:22 -0000 1.127
+++ symtab.c 19 Feb 2004 17:13:11 -0000
@@ -672,8 +672,10 @@ init_sal (struct symtab_and_line *sal)
-/* Find which partial symtab on contains PC and SECTION. Return 0 if none. */-
+/* Find which partial symtab contains PC and SECTION. Return 0 if
+ none. We return the psymtab that contains a symbol whose address
+ exactly matches PC, or, if we cannot find an exact match, the
+ psymtab that contains a symbol whose address is closest to PC. */
struct partial_symtab *
find_pc_sect_psymtab (CORE_ADDR pc, asection *section)
{
@@ -698,6 +700,8 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
if (pc >= pst->textlow && pc < pst->texthigh)
{
struct partial_symtab *tpst;
+ struct partial_symtab *best_pst = pst;
+ struct partial_symbol *best_psym = NULL;
/* An objfile that has its functions reordered might have
many partial symbol tables containing the PC, but
@@ -710,6 +714,13 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
if (msymbol == NULL)
return (pst);
+ /* The code range of partial symtabs sometimes overlap, so, in
+ the loop below, we need to check all partial symtabs and
+ find the one that fits better for the given PC address. We
+ select the partial symtab that contains a symbol whose
+ address is closest to the PC address. By closest we mean
+ that find_pc_sect_symbol returns the symbol with address
+ that is closest and still less than the given PC. */
for (tpst = pst; tpst != NULL; tpst = tpst->next)
{
if (pc >= tpst->textlow && pc < tpst->texthigh)
@@ -721,9 +732,33 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
&& SYMBOL_VALUE_ADDRESS (p)
== SYMBOL_VALUE_ADDRESS (msymbol))
return (tpst);
+ if (p != NULL)
+ {
+ /* We found a symbol in this partial symtab which
+ matches (or is closest to) PC, check whether it
+ is closer than our current BEST_PSYM. Since
+ this symbol address is necessarily lower or
+ equal to PC, the symbol closer to PC is the
+ symbol which address is the highest. */
+ /* This way we return the psymtab which contains
+ such best match symbol. This can help in cases
+ where the symbol information/debuginfo is not
+ complete, like for instance on IRIX6 with gcc,
+ where no debug info is emitted for
+ statics. (See also the nodebug.exp
+ testcase.) */
+ if (best_psym == NULL
+ || SYMBOL_VALUE_ADDRESS (p)
+ > SYMBOL_VALUE_ADDRESS (best_psym))
+ {
+ best_psym = p;
+ best_pst = tpst;
+ }
+ }
+
}
}
- return (pst);
+ return (best_pst);
}
}
return (NULL);
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [RFC/RFA] find_pc_sect_psymtab(): symbol table not always complete
2004-02-19 19:01 ` Elena Zannoni
@ 2004-02-20 17:11 ` Joel Brobecker
0 siblings, 0 replies; 7+ messages in thread
From: Joel Brobecker @ 2004-02-20 17:11 UTC (permalink / raw)
To: Elena Zannoni; +Cc: gdb-patches
Elena,
> Joel, I committed an updated version of your patch. By updated I mean
> with new/more comments. Now let's keep an eye on any apparently
> unrelated breakage :-)
>
> elena
>
> 2004-02-19 Joel Brobecker <brobecker@gnat.com>
>
> Committed by Elena Zannoni <ezannoni@redhat.com>
> * symtab.c (find_pc_sect_psymtab): Return the psymtab that
> contains a symbol wich is the best, non-exact match for the given
> pc. Update comments.
Thanks. You are too kind to have fixed the comments for me...
--
Joel
^ permalink raw reply [flat|nested] 7+ messages in thread