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6.0 BRANCH PATCH: fix dbxread handling of variables' section offsets
- From: Jim Blandy <jimb at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: 20 Sep 2003 20:45:07 -0500
- Subject: 6.0 BRANCH PATCH: fix dbxread handling of variables' section offsets
This patch is smaller than the ChangeLog entries would suggest.
2003-09-19 Jim Blandy <jimb@redhat.com>
Merge from mainline:
2003-09-12 Jim Blandy <jimb@redhat.com>
* dbxread.c (read_dbx_symtab): Don't report an internal error if
the file has no .data, .bss, or .rodata sections. Instead wait
until we see a variable alleged to live in one of those sections.
2003-09-12 Jim Blandy <jimb@redhat.com>
* dbxread.c (read_dbx_symtab): If we have no .data section and no
.bss section, presume that any variables we find live in the
.rodata section.
2003-09-12 Jim Blandy <jimb@redhat.com>
* dbxread.c (read_dbx_symtab): Add FIXME about finding section
offsets for global and static variables.
2003-09-09 Jim Blandy <jimb@redhat.com>
* dbxread.c (read_dbx_symtab): The N_DATA and N_DATA | N_EXT
symbol types are, by definition, in the .data section, so it is
correct to use SECT_OFF_DATA (objfile) here, not data_sect_index.
If there is no .data section, there should be no N_DATA or N_DATA
| N_EXT symbols.
2003-07-10 Jim Blandy <jimb@redhat.com>
* Makefile.in (dbxread.o): Note new dependency on $(gdb_assert_h).
* dbxread.c: #include "gdb_assert.h".
(read_dbx_symtab): If the objfile has no .data section, use the
section index for the .bss section instead.
Index: gdb/Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.410.2.14
diff -c -r1.410.2.14 Makefile.in
*** gdb/Makefile.in 18 Aug 2003 18:10:52 -0000 1.410.2.14
--- gdb/Makefile.in 20 Sep 2003 00:12:18 -0000
***************
*** 1663,1669 ****
$(gdb_stat_h) $(symtab_h) $(breakpoint_h) $(target_h) $(gdbcore_h) \
$(libaout_h) $(symfile_h) $(objfiles_h) $(buildsym_h) $(stabsread_h) \
$(gdb_stabs_h) $(demangle_h) $(language_h) $(complaints_h) \
! $(cp_abi_h) $(aout_aout64_h) $(aout_stab_gnu_h)
dcache.o: dcache.c $(defs_h) $(dcache_h) $(gdbcmd_h) $(gdb_string_h) \
$(gdbcore_h) $(target_h)
delta68-nat.o: delta68-nat.c $(defs_h)
--- 1663,1669 ----
$(gdb_stat_h) $(symtab_h) $(breakpoint_h) $(target_h) $(gdbcore_h) \
$(libaout_h) $(symfile_h) $(objfiles_h) $(buildsym_h) $(stabsread_h) \
$(gdb_stabs_h) $(demangle_h) $(language_h) $(complaints_h) \
! $(cp_abi_h) $(aout_aout64_h) $(aout_stab_gnu_h) $(gdb_assert_h)
dcache.o: dcache.c $(defs_h) $(dcache_h) $(gdbcmd_h) $(gdb_string_h) \
$(gdbcore_h) $(target_h)
delta68-nat.o: delta68-nat.c $(defs_h)
Index: gdb/dbxread.c
===================================================================
RCS file: /cvs/src/src/gdb/dbxread.c,v
retrieving revision 1.48
diff -c -r1.48 dbxread.c
*** gdb/dbxread.c 11 Jun 2003 22:27:10 -0000 1.48
--- gdb/dbxread.c 20 Sep 2003 00:12:20 -0000
***************
*** 58,63 ****
--- 58,64 ----
#include "language.h" /* Needed for local_hex_string */
#include "complaints.h"
#include "cp-abi.h"
+ #include "gdb_assert.h"
#include "aout/aout64.h"
#include "aout/stab_gnu.h" /* We always use GNU stabs, not native, now */
***************
*** 1304,1309 ****
--- 1305,1311 ----
struct cleanup *back_to;
bfd *abfd;
int textlow_not_set;
+ int data_sect_index;
/* Current partial symtab */
struct partial_symtab *pst;
***************
*** 1355,1360 ****
--- 1357,1394 ----
textlow_not_set = 1;
has_line_numbers = 0;
+ /* FIXME: jimb/2003-09-12: We don't apply the right section's offset
+ to global and static variables. The stab for a global or static
+ variable doesn't give us any indication of which section it's in,
+ so we can't tell immediately which offset in
+ objfile->section_offsets we should apply to the variable's
+ address.
+
+ We could certainly find out which section contains the variable
+ by looking up the variable's unrelocated address with
+ find_pc_section, but that would be expensive; this is the
+ function that constructs the partial symbol tables by examining
+ every symbol in the entire executable, and it's
+ performance-critical. So that expense would not be welcome. I'm
+ not sure what to do about this at the moment.
+
+ What we have done for years is to simply assume that the .data
+ section's offset is appropriate for all global and static
+ variables. Recently, this was expanded to fall back to the .bss
+ section's offset if there is no .data section, and then to the
+ .rodata section's offset. */
+ data_sect_index = objfile->sect_index_data;
+ if (data_sect_index == -1)
+ data_sect_index = SECT_OFF_BSS (objfile);
+ if (data_sect_index == -1)
+ data_sect_index = SECT_OFF_RODATA (objfile);
+
+ /* If data_sect_index is still -1, that's okay. It's perfectly fine
+ for the file to have no .data, no .bss, and no .text at all, if
+ it also has no global or static variables. If it does, we will
+ get an internal error from an ANOFFSET macro below when we try to
+ use data_sect_index. */
+
for (symnum = 0; symnum < DBX_SYMCOUNT (objfile); symnum++)
{
/* Get the symbol for this run and pull out some info */
***************
*** 1757,1763 ****
switch (p[1])
{
case 'S':
! nlist.n_value += ANOFFSET (objfile->section_offsets, SECT_OFF_DATA (objfile));
#ifdef STATIC_TRANSFORM_NAME
namestring = STATIC_TRANSFORM_NAME (namestring);
#endif
--- 1791,1797 ----
switch (p[1])
{
case 'S':
! nlist.n_value += ANOFFSET (objfile->section_offsets, data_sect_index);
#ifdef STATIC_TRANSFORM_NAME
namestring = STATIC_TRANSFORM_NAME (namestring);
#endif
***************
*** 1768,1774 ****
psymtab_language, objfile);
continue;
case 'G':
! nlist.n_value += ANOFFSET (objfile->section_offsets, SECT_OFF_DATA (objfile));
/* The addresses in these entries are reported to be
wrong. See the code that reads 'G's for symtabs. */
add_psymbol_to_list (namestring, p - namestring,
--- 1802,1808 ----
psymtab_language, objfile);
continue;
case 'G':
! nlist.n_value += ANOFFSET (objfile->section_offsets, data_sect_index);
/* The addresses in these entries are reported to be
wrong. See the code that reads 'G's for symtabs. */
add_psymbol_to_list (namestring, p - namestring,