/* GDB routines for manipulating the minimal symbol tables.
- Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
- 2002, 2003
- Free Software Foundation, Inc.
+ Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
+ 2002, 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
Contributed by Cygnus Support, using pieces from other GDB modules.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* This file contains support routines for creating, manipulating, and
Note: One instance where there may be duplicate minimal symbols with
the same name is when the symbol tables for a shared library and the
symbol tables for an executable contain global symbols with the same
- names (the dynamic linker deals with the duplication). */
+ names (the dynamic linker deals with the duplication).
+
+ It's also possible to have minimal symbols with different mangled
+ names, but identical demangled names. For example, the GNU C++ v3
+ ABI requires the generation of two (or perhaps three) copies of
+ constructor functions --- "in-charge", "not-in-charge", and
+ "allocate" copies; destructors may be duplicated as well.
+ Obviously, there must be distinct mangled names for each of these,
+ but the demangled names are all the same: S::S or S::~S. */
struct minimal_symbol *
lookup_minimal_symbol (const char *name, const char *sfile,
unsigned int hash = msymbol_hash (name) % MINIMAL_SYMBOL_HASH_SIZE;
unsigned int dem_hash = msymbol_hash_iw (name) % MINIMAL_SYMBOL_HASH_SIZE;
-#ifdef SOFUN_ADDRESS_MAYBE_MISSING
if (sfile != NULL)
{
char *p = strrchr (sfile, '/');
if (p != NULL)
sfile = p + 1;
}
-#endif
for (objfile = object_files;
objfile != NULL && found_symbol == NULL;
objfile = objfile->next)
{
- if (objf == NULL || objf == objfile)
+ if (objf == NULL || objf == objfile
+ || objf->separate_debug_objfile == objfile)
{
/* Do two passes: the first over the ordinary hash table,
and the second over the demangled hash table. */
case mst_file_text:
case mst_file_data:
case mst_file_bss:
-#ifdef SOFUN_ADDRESS_MAYBE_MISSING
if (sfile == NULL
|| strcmp (msymbol->filename, sfile) == 0)
found_file_symbol = msymbol;
-#else
- /* We have neither the ability nor the need to
- deal with the SFILE parameter. If we find
- more than one symbol, just return the latest
- one (the user can't expect useful behavior in
- that case). */
- found_file_symbol = msymbol;
-#endif
break;
case mst_solib_trampoline:
objfile != NULL && found_symbol == NULL;
objfile = objfile->next)
{
- if (objf == NULL || objf == objfile)
+ if (objf == NULL || objf == objfile
+ || objf->separate_debug_objfile == objfile)
{
for (msymbol = objfile->msymbol_hash[hash];
msymbol != NULL && found_symbol == NULL;
objfile != NULL && found_symbol == NULL;
objfile = objfile->next)
{
- if (objf == NULL || objf == objfile)
+ if (objf == NULL || objf == objfile
+ || objf->separate_debug_objfile == objfile)
{
for (msymbol = objfile->msymbol_hash[hash];
msymbol != NULL && found_symbol == NULL;
return NULL;
}
-
/* Search through the minimal symbol table for each objfile and find
the symbol whose address is the largest address that is still less
- than or equal to PC, and matches SECTION (if non-null). Returns a
+ than or equal to PC, and matches SECTION (if non-NULL). Returns a
pointer to the minimal symbol if such a symbol is found, or NULL if
PC is not in a suitable range. Note that we need to look through
ALL the minimal symbol tables before deciding on the symbol that
struct minimal_symbol *best_symbol = NULL;
struct obj_section *pc_section;
- /* pc has to be in a known section. This ensures that anything beyond
- the end of the last segment doesn't appear to be part of the last
- function in the last segment. */
+ /* PC has to be in a known section. This ensures that anything
+ beyond the end of the last segment doesn't appear to be part of
+ the last function in the last segment. */
pc_section = find_pc_section (pc);
if (pc_section == NULL)
return NULL;
- /* If no section was specified, then just make sure that the PC is in
- the same section as the minimal symbol we find. */
- if (section == NULL)
- section = pc_section->the_bfd_section;
+ /* We can not require the symbol found to be in pc_section, because
+ e.g. IRIX 6.5 mdebug relies on this code returning an absolute
+ symbol - but find_pc_section won't return an absolute section and
+ hence the code below would skip over absolute symbols. We can
+ still take advantage of the call to find_pc_section, though - the
+ object file still must match. In case we have separate debug
+ files, search both the file and its separate debug file. There's
+ no telling which one will have the minimal symbols. */
- /* FIXME drow/2003-07-19: Should we also check that PC is in SECTION
- if we were passed a non-NULL SECTION argument? */
+ objfile = pc_section->objfile;
+ if (objfile->separate_debug_objfile)
+ objfile = objfile->separate_debug_objfile;
- for (objfile = object_files;
- objfile != NULL;
- objfile = objfile->next)
+ for (; objfile != NULL; objfile = objfile->separate_debug_objfile_backlink)
{
/* If this objfile has a minimal symbol table, go search it using
a binary search. Note that a minimal symbol table always consists
if (objfile->minimal_symbol_count > 0)
{
+ int best_zero_sized = -1;
+
msymbol = objfile->msymbols;
lo = 0;
hi = objfile->minimal_symbol_count - 1;
== SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1])))
hi++;
+ /* Skip various undesirable symbols. */
+ while (hi >= 0)
+ {
+ /* Skip any absolute symbols. This is apparently
+ what adb and dbx do, and is needed for the CM-5.
+ There are two known possible problems: (1) on
+ ELF, apparently end, edata, etc. are absolute.
+ Not sure ignoring them here is a big deal, but if
+ we want to use them, the fix would go in
+ elfread.c. (2) I think shared library entry
+ points on the NeXT are absolute. If we want
+ special handling for this it probably should be
+ triggered by a special mst_abs_or_lib or some
+ such. */
+
+ if (msymbol[hi].type == mst_abs)
+ {
+ hi--;
+ continue;
+ }
+
+ /* If SECTION was specified, skip any symbol from
+ wrong section. */
+ if (section
+ /* Some types of debug info, such as COFF,
+ don't fill the bfd_section member, so don't
+ throw away symbols on those platforms. */
+ && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
+ && (!matching_bfd_sections
+ (SYMBOL_BFD_SECTION (&msymbol[hi]), section)))
+ {
+ hi--;
+ continue;
+ }
+
+ /* If the minimal symbol has a zero size, save it
+ but keep scanning backwards looking for one with
+ a non-zero size. A zero size may mean that the
+ symbol isn't an object or function (e.g. a
+ label), or it may just mean that the size was not
+ specified. */
+ if (MSYMBOL_SIZE (&msymbol[hi]) == 0
+ && best_zero_sized == -1)
+ {
+ best_zero_sized = hi;
+ hi--;
+ continue;
+ }
+
+ /* If we are past the end of the current symbol, try
+ the previous symbol if it has a larger overlapping
+ size. This happens on i686-pc-linux-gnu with glibc;
+ the nocancel variants of system calls are inside
+ the cancellable variants, but both have sizes. */
+ if (hi > 0
+ && MSYMBOL_SIZE (&msymbol[hi]) != 0
+ && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
+ + MSYMBOL_SIZE (&msymbol[hi]))
+ && pc < (SYMBOL_VALUE_ADDRESS (&msymbol[hi - 1])
+ + MSYMBOL_SIZE (&msymbol[hi - 1])))
+ {
+ hi--;
+ continue;
+ }
+
+ /* Otherwise, this symbol must be as good as we're going
+ to get. */
+ break;
+ }
+
+ /* If HI has a zero size, and best_zero_sized is set,
+ then we had two or more zero-sized symbols; prefer
+ the first one we found (which may have a higher
+ address). Also, if we ran off the end, be sure
+ to back up. */
+ if (best_zero_sized != -1
+ && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
+ hi = best_zero_sized;
+
+ /* If the minimal symbol has a non-zero size, and this
+ PC appears to be outside the symbol's contents, then
+ refuse to use this symbol. If we found a zero-sized
+ symbol with an address greater than this symbol's,
+ use that instead. We assume that if symbols have
+ specified sizes, they do not overlap. */
+
+ if (hi >= 0
+ && MSYMBOL_SIZE (&msymbol[hi]) != 0
+ && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
+ + MSYMBOL_SIZE (&msymbol[hi])))
+ {
+ if (best_zero_sized != -1)
+ hi = best_zero_sized;
+ else
+ /* Go on to the next object file. */
+ continue;
+ }
+
/* The minimal symbol indexed by hi now is the best one in this
objfile's minimal symbol table. See if it is the best one
overall. */
- /* Skip any absolute symbols. This is apparently what adb
- and dbx do, and is needed for the CM-5. There are two
- known possible problems: (1) on ELF, apparently end, edata,
- etc. are absolute. Not sure ignoring them here is a big
- deal, but if we want to use them, the fix would go in
- elfread.c. (2) I think shared library entry points on the
- NeXT are absolute. If we want special handling for this
- it probably should be triggered by a special
- mst_abs_or_lib or some such. */
- while (hi >= 0
- && msymbol[hi].type == mst_abs)
- --hi;
-
- /* If "section" specified, skip any symbol from wrong section */
- /* This is the new code that distinguishes it from the old function */
- if (section)
- while (hi >= 0
- /* Some types of debug info, such as COFF,
- don't fill the bfd_section member, so don't
- throw away symbols on those platforms. */
- && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
- && SYMBOL_BFD_SECTION (&msymbol[hi]) != section)
- --hi;
-
if (hi >= 0
&& ((best_symbol == NULL) ||
(SYMBOL_VALUE_ADDRESS (best_symbol) <
struct minimal_symbol *
lookup_minimal_symbol_by_pc (CORE_ADDR pc)
{
- return lookup_minimal_symbol_by_pc_section (pc, find_pc_mapped_section (pc));
+ /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to
+ force the section but that (well unless you're doing overlay
+ debugging) always returns NULL making the call somewhat useless. */
+ struct obj_section *section = find_pc_section (pc);
+ if (section == NULL)
+ return NULL;
+ return lookup_minimal_symbol_by_pc_section (pc, section->the_bfd_section);
}
\f
struct msym_bunch *new;
struct minimal_symbol *msymbol;
- if (ms_type == mst_file_text)
- {
- /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
- the minimal symbols, because if there is also another symbol
- at the same address (e.g. the first function of the file),
- lookup_minimal_symbol_by_pc would have no way of getting the
- right one. */
- if (name[0] == 'g'
- && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
- || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
- return (NULL);
+ /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
+ the minimal symbols, because if there is also another symbol
+ at the same address (e.g. the first function of the file),
+ lookup_minimal_symbol_by_pc would have no way of getting the
+ right one. */
+ if (ms_type == mst_file_text && name[0] == 'g'
+ && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
+ || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
+ return (NULL);
- {
- const char *tempstring = name;
- if (tempstring[0] == get_symbol_leading_char (objfile->obfd))
- ++tempstring;
- if (strncmp (tempstring, "__gnu_compiled", 14) == 0)
- return (NULL);
- }
- }
+ /* It's safe to strip the leading char here once, since the name
+ is also stored stripped in the minimal symbol table. */
+ if (name[0] == get_symbol_leading_char (objfile->obfd))
+ ++name;
+
+ if (ms_type == mst_file_text && strncmp (name, "__gnu_compiled", 14) == 0)
+ return (NULL);
if (msym_bunch_index == BUNCH_SIZE)
{
MSYMBOL_TYPE (msymbol) = ms_type;
/* FIXME: This info, if it remains, needs its own field. */
MSYMBOL_INFO (msymbol) = info; /* FIXME! */
+ MSYMBOL_SIZE (msymbol) = 0;
/* The hash pointers must be cleared! If they're not,
add_minsym_to_hash_table will NOT add this msymbol to the hash table. */
Note that we are not concerned here about recovering the space that
is potentially freed up, because the strings themselves are allocated
- on the symbol_obstack, and will get automatically freed when the symbol
+ on the objfile_obstack, and will get automatically freed when the symbol
table is freed. The caller can free up the unused minimal symbols at
the end of the compacted region if their allocation strategy allows it.
add_minsym_to_hash_table (msym, objfile->msymbol_hash);
msym->demangled_hash_next = 0;
- if (SYMBOL_DEMANGLED_NAME (msym) != NULL)
+ if (SYMBOL_SEARCH_NAME (msym) != SYMBOL_LINKAGE_NAME (msym))
add_minsym_to_demangled_hash_table (msym,
objfile->msymbol_demangled_hash);
}
struct msym_bunch *bunch;
struct minimal_symbol *msymbols;
int alloc_count;
- char leading_char;
if (msym_count > 0)
{
we will give back the excess space. */
alloc_count = msym_count + objfile->minimal_symbol_count + 1;
- obstack_blank (&objfile->symbol_obstack,
+ obstack_blank (&objfile->objfile_obstack,
alloc_count * sizeof (struct minimal_symbol));
msymbols = (struct minimal_symbol *)
- obstack_base (&objfile->symbol_obstack);
+ obstack_base (&objfile->objfile_obstack);
/* Copy in the existing minimal symbols, if there are any. */
each bunch is full. */
mcount = objfile->minimal_symbol_count;
- leading_char = get_symbol_leading_char (objfile->obfd);
for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next)
{
for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
- {
- msymbols[mcount] = bunch->contents[bindex];
- if (SYMBOL_LINKAGE_NAME (&msymbols[mcount])[0] == leading_char)
- {
- SYMBOL_LINKAGE_NAME (&msymbols[mcount])++;
- }
- }
+ msymbols[mcount] = bunch->contents[bindex];
msym_bunch_index = BUNCH_SIZE;
}
mcount = compact_minimal_symbols (msymbols, mcount, objfile);
- obstack_blank (&objfile->symbol_obstack,
+ obstack_blank (&objfile->objfile_obstack,
(mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
msymbols = (struct minimal_symbol *)
- obstack_finish (&objfile->symbol_obstack);
+ obstack_finish (&objfile->objfile_obstack);
/* We also terminate the minimal symbol table with a "null symbol",
which is *not* included in the size of the table. This makes it
SYMBOL_LINKAGE_NAME (&msymbols[mcount]) = NULL;
SYMBOL_VALUE_ADDRESS (&msymbols[mcount]) = 0;
MSYMBOL_INFO (&msymbols[mcount]) = NULL;
+ MSYMBOL_SIZE (&msymbols[mcount]) = 0;
MSYMBOL_TYPE (&msymbols[mcount]) = mst_unknown;
SYMBOL_INIT_LANGUAGE_SPECIFIC (&msymbols[mcount], language_unknown);
/* Attach the minimal symbol table to the specified objfile.
- The strings themselves are also located in the symbol_obstack
+ The strings themselves are also located in the objfile_obstack
of this objfile. */
objfile->minimal_symbol_count = mcount;
a duplicate function in case this matters someday. */
CORE_ADDR
-find_solib_trampoline_target (CORE_ADDR pc)
+find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
{
struct objfile *objfile;
struct minimal_symbol *msymbol;