f29dff0a09
* symfile.h (dwarf2_build_psymtabs): Remove mainline parameter in prototype. * dwarf2read.c (dwarf2_build_psymtabs): Remove mainline paramter in definition, simplify code assuming it is always 0. * coffread.c (coff_symfile_read): Adjust call. * elfread.c (elf_symfile_read): Ditto. * machoread.c (macho_symfile_read): Explicitely calls init_psymbol_list if mainline is set.
908 lines
29 KiB
C
908 lines
29 KiB
C
/* Read ELF (Executable and Linking Format) object files for GDB.
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Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
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2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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Free Software Foundation, Inc.
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Written by Fred Fish at Cygnus Support.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "bfd.h"
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#include "gdb_string.h"
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#include "elf-bfd.h"
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#include "elf/common.h"
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#include "elf/internal.h"
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#include "elf/mips.h"
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#include "symtab.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "buildsym.h"
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#include "stabsread.h"
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#include "gdb-stabs.h"
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#include "complaints.h"
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#include "demangle.h"
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extern void _initialize_elfread (void);
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/* The struct elfinfo is available only during ELF symbol table and
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psymtab reading. It is destroyed at the completion of psymtab-reading.
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It's local to elf_symfile_read. */
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struct elfinfo
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{
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asection *stabsect; /* Section pointer for .stab section */
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asection *stabindexsect; /* Section pointer for .stab.index section */
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asection *mdebugsect; /* Section pointer for .mdebug section */
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};
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static void free_elfinfo (void *);
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/* Locate the segments in ABFD. */
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static struct symfile_segment_data *
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elf_symfile_segments (bfd *abfd)
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{
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Elf_Internal_Phdr *phdrs, **segments;
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long phdrs_size;
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int num_phdrs, num_segments, num_sections, i;
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asection *sect;
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struct symfile_segment_data *data;
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phdrs_size = bfd_get_elf_phdr_upper_bound (abfd);
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if (phdrs_size == -1)
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return NULL;
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phdrs = alloca (phdrs_size);
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num_phdrs = bfd_get_elf_phdrs (abfd, phdrs);
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if (num_phdrs == -1)
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return NULL;
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num_segments = 0;
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segments = alloca (sizeof (Elf_Internal_Phdr *) * num_phdrs);
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for (i = 0; i < num_phdrs; i++)
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if (phdrs[i].p_type == PT_LOAD)
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segments[num_segments++] = &phdrs[i];
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if (num_segments == 0)
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return NULL;
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data = XZALLOC (struct symfile_segment_data);
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data->num_segments = num_segments;
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data->segment_bases = XCALLOC (num_segments, CORE_ADDR);
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data->segment_sizes = XCALLOC (num_segments, CORE_ADDR);
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for (i = 0; i < num_segments; i++)
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{
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data->segment_bases[i] = segments[i]->p_vaddr;
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data->segment_sizes[i] = segments[i]->p_memsz;
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}
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num_sections = bfd_count_sections (abfd);
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data->segment_info = XCALLOC (num_sections, int);
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for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next)
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{
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int j;
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CORE_ADDR vma;
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if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
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continue;
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vma = bfd_get_section_vma (abfd, sect);
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for (j = 0; j < num_segments; j++)
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if (segments[j]->p_memsz > 0
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&& vma >= segments[j]->p_vaddr
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&& (vma - segments[j]->p_vaddr) < segments[j]->p_memsz)
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{
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data->segment_info[i] = j + 1;
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break;
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}
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/* We should have found a segment for every non-empty section.
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If we haven't, we will not relocate this section by any
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offsets we apply to the segments. As an exception, do not
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warn about SHT_NOBITS sections; in normal ELF execution
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environments, SHT_NOBITS means zero-initialized and belongs
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in a segment, but in no-OS environments some tools (e.g. ARM
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RealView) use SHT_NOBITS for uninitialized data. Since it is
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uninitialized, it doesn't need a program header. Such
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binaries are not relocatable. */
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if (bfd_get_section_size (sect) > 0 && j == num_segments
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&& (bfd_get_section_flags (abfd, sect) & SEC_LOAD) != 0)
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warning (_("Loadable segment \"%s\" outside of ELF segments"),
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bfd_section_name (abfd, sect));
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}
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return data;
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}
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/* We are called once per section from elf_symfile_read. We
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need to examine each section we are passed, check to see
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if it is something we are interested in processing, and
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if so, stash away some access information for the section.
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For now we recognize the dwarf debug information sections and
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line number sections from matching their section names. The
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ELF definition is no real help here since it has no direct
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knowledge of DWARF (by design, so any debugging format can be
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used).
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We also recognize the ".stab" sections used by the Sun compilers
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released with Solaris 2.
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FIXME: The section names should not be hardwired strings (what
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should they be? I don't think most object file formats have enough
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section flags to specify what kind of debug section it is
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-kingdon). */
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static void
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elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip)
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{
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struct elfinfo *ei;
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ei = (struct elfinfo *) eip;
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if (strcmp (sectp->name, ".stab") == 0)
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{
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ei->stabsect = sectp;
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}
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else if (strcmp (sectp->name, ".stab.index") == 0)
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{
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ei->stabindexsect = sectp;
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}
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else if (strcmp (sectp->name, ".mdebug") == 0)
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{
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ei->mdebugsect = sectp;
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}
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}
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static struct minimal_symbol *
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record_minimal_symbol (const char *name, int name_len, int copy_name,
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CORE_ADDR address,
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enum minimal_symbol_type ms_type,
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asection *bfd_section, struct objfile *objfile)
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{
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struct gdbarch *gdbarch = get_objfile_arch (objfile);
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if (ms_type == mst_text || ms_type == mst_file_text)
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address = gdbarch_smash_text_address (gdbarch, address);
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return prim_record_minimal_symbol_full (name, name_len, copy_name, address,
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ms_type, bfd_section->index,
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bfd_section, objfile);
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}
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/*
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LOCAL FUNCTION
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elf_symtab_read -- read the symbol table of an ELF file
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SYNOPSIS
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void elf_symtab_read (struct objfile *objfile, int type,
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long number_of_symbols, asymbol **symbol_table)
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DESCRIPTION
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Given an objfile, a symbol table, and a flag indicating whether the
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symbol table contains regular, dynamic, or synthetic symbols, add all
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the global function and data symbols to the minimal symbol table.
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In stabs-in-ELF, as implemented by Sun, there are some local symbols
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defined in the ELF symbol table, which can be used to locate
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the beginnings of sections from each ".o" file that was linked to
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form the executable objfile. We gather any such info and record it
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in data structures hung off the objfile's private data.
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*/
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#define ST_REGULAR 0
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#define ST_DYNAMIC 1
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#define ST_SYNTHETIC 2
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static void
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elf_symtab_read (struct objfile *objfile, int type,
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long number_of_symbols, asymbol **symbol_table,
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int copy_names)
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{
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struct gdbarch *gdbarch = get_objfile_arch (objfile);
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long storage_needed;
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asymbol *sym;
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long i;
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CORE_ADDR symaddr;
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CORE_ADDR offset;
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enum minimal_symbol_type ms_type;
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/* If sectinfo is nonNULL, it contains section info that should end up
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filed in the objfile. */
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struct stab_section_info *sectinfo = NULL;
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/* If filesym is nonzero, it points to a file symbol, but we haven't
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seen any section info for it yet. */
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asymbol *filesym = 0;
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/* Name of filesym. This is either a constant string or is saved on
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the objfile's obstack. */
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char *filesymname = "";
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struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
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int stripped = (bfd_get_symcount (objfile->obfd) == 0);
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for (i = 0; i < number_of_symbols; i++)
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{
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sym = symbol_table[i];
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if (sym->name == NULL || *sym->name == '\0')
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{
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/* Skip names that don't exist (shouldn't happen), or names
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that are null strings (may happen). */
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continue;
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}
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/* Skip "special" symbols, e.g. ARM mapping symbols. These are
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symbols which do not correspond to objects in the symbol table,
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but have some other target-specific meaning. */
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if (bfd_is_target_special_symbol (objfile->obfd, sym))
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{
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if (gdbarch_record_special_symbol_p (gdbarch))
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gdbarch_record_special_symbol (gdbarch, objfile, sym);
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continue;
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}
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offset = ANOFFSET (objfile->section_offsets, sym->section->index);
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if (type == ST_DYNAMIC
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&& sym->section == &bfd_und_section
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&& (sym->flags & BSF_FUNCTION))
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{
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struct minimal_symbol *msym;
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bfd *abfd = objfile->obfd;
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asection *sect;
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/* Symbol is a reference to a function defined in
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a shared library.
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If its value is non zero then it is usually the address
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of the corresponding entry in the procedure linkage table,
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plus the desired section offset.
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If its value is zero then the dynamic linker has to resolve
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the symbol. We are unable to find any meaningful address
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for this symbol in the executable file, so we skip it. */
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symaddr = sym->value;
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if (symaddr == 0)
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continue;
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/* sym->section is the undefined section. However, we want to
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record the section where the PLT stub resides with the
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minimal symbol. Search the section table for the one that
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covers the stub's address. */
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for (sect = abfd->sections; sect != NULL; sect = sect->next)
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{
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if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0)
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continue;
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if (symaddr >= bfd_get_section_vma (abfd, sect)
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&& symaddr < bfd_get_section_vma (abfd, sect)
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+ bfd_get_section_size (sect))
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break;
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}
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if (!sect)
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continue;
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symaddr += ANOFFSET (objfile->section_offsets, sect->index);
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msym = record_minimal_symbol
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(sym->name, strlen (sym->name), copy_names,
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symaddr, mst_solib_trampoline, sect, objfile);
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if (msym != NULL)
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msym->filename = filesymname;
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continue;
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}
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/* If it is a nonstripped executable, do not enter dynamic
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symbols, as the dynamic symbol table is usually a subset
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of the main symbol table. */
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if (type == ST_DYNAMIC && !stripped)
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continue;
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if (sym->flags & BSF_FILE)
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{
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/* STT_FILE debugging symbol that helps stabs-in-elf debugging.
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Chain any old one onto the objfile; remember new sym. */
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if (sectinfo != NULL)
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{
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sectinfo->next = dbx->stab_section_info;
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dbx->stab_section_info = sectinfo;
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sectinfo = NULL;
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}
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filesym = sym;
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filesymname =
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obsavestring ((char *) filesym->name, strlen (filesym->name),
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&objfile->objfile_obstack);
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}
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else if (sym->flags & BSF_SECTION_SYM)
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continue;
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else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK))
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{
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struct minimal_symbol *msym;
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/* Select global/local/weak symbols. Note that bfd puts abs
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symbols in their own section, so all symbols we are
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interested in will have a section. */
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/* Bfd symbols are section relative. */
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symaddr = sym->value + sym->section->vma;
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/* Relocate all non-absolute and non-TLS symbols by the
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section offset. */
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if (sym->section != &bfd_abs_section
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&& !(sym->section->flags & SEC_THREAD_LOCAL))
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{
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symaddr += offset;
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}
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/* For non-absolute symbols, use the type of the section
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they are relative to, to intuit text/data. Bfd provides
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no way of figuring this out for absolute symbols. */
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if (sym->section == &bfd_abs_section)
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{
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/* This is a hack to get the minimal symbol type
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right for Irix 5, which has absolute addresses
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with special section indices for dynamic symbols.
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NOTE: uweigand-20071112: Synthetic symbols do not
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have an ELF-private part, so do not touch those. */
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unsigned int shndx = type == ST_SYNTHETIC ? 0 :
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((elf_symbol_type *) sym)->internal_elf_sym.st_shndx;
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switch (shndx)
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{
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case SHN_MIPS_TEXT:
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ms_type = mst_text;
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break;
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case SHN_MIPS_DATA:
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ms_type = mst_data;
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break;
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case SHN_MIPS_ACOMMON:
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ms_type = mst_bss;
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break;
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default:
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ms_type = mst_abs;
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}
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/* If it is an Irix dynamic symbol, skip section name
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symbols, relocate all others by section offset. */
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if (ms_type != mst_abs)
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{
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if (sym->name[0] == '.')
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continue;
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symaddr += offset;
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}
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}
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else if (sym->section->flags & SEC_CODE)
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{
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if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
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{
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ms_type = mst_text;
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}
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else if ((sym->name[0] == '.' && sym->name[1] == 'L')
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|| ((sym->flags & BSF_LOCAL)
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&& sym->name[0] == '$'
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&& sym->name[1] == 'L'))
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/* Looks like a compiler-generated label. Skip
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it. The assembler should be skipping these (to
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keep executables small), but apparently with
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gcc on the (deleted) delta m88k SVR4, it loses.
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So to have us check too should be harmless (but
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I encourage people to fix this in the assembler
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instead of adding checks here). */
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continue;
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else
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{
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ms_type = mst_file_text;
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}
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}
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else if (sym->section->flags & SEC_ALLOC)
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{
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if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
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{
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if (sym->section->flags & SEC_LOAD)
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{
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ms_type = mst_data;
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}
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else
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{
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ms_type = mst_bss;
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}
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}
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else if (sym->flags & BSF_LOCAL)
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{
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/* Named Local variable in a Data section.
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Check its name for stabs-in-elf. */
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int special_local_sect;
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if (strcmp ("Bbss.bss", sym->name) == 0)
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special_local_sect = SECT_OFF_BSS (objfile);
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else if (strcmp ("Ddata.data", sym->name) == 0)
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special_local_sect = SECT_OFF_DATA (objfile);
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else if (strcmp ("Drodata.rodata", sym->name) == 0)
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special_local_sect = SECT_OFF_RODATA (objfile);
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else
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special_local_sect = -1;
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if (special_local_sect >= 0)
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{
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/* Found a special local symbol. Allocate a
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sectinfo, if needed, and fill it in. */
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if (sectinfo == NULL)
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{
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int max_index;
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size_t size;
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max_index = SECT_OFF_BSS (objfile);
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if (objfile->sect_index_data > max_index)
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max_index = objfile->sect_index_data;
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if (objfile->sect_index_rodata > max_index)
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max_index = objfile->sect_index_rodata;
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/* max_index is the largest index we'll
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use into this array, so we must
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allocate max_index+1 elements for it.
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However, 'struct stab_section_info'
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already includes one element, so we
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need to allocate max_index aadditional
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elements. */
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size = (sizeof (struct stab_section_info)
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+ (sizeof (CORE_ADDR)
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* max_index));
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sectinfo = (struct stab_section_info *)
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xmalloc (size);
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memset (sectinfo, 0, size);
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sectinfo->num_sections = max_index;
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if (filesym == NULL)
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{
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complaint (&symfile_complaints,
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_("elf/stab section information %s without a preceding file symbol"),
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sym->name);
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}
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else
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{
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sectinfo->filename =
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(char *) filesym->name;
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}
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}
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if (sectinfo->sections[special_local_sect] != 0)
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complaint (&symfile_complaints,
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_("duplicated elf/stab section information for %s"),
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sectinfo->filename);
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/* BFD symbols are section relative. */
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symaddr = sym->value + sym->section->vma;
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/* Relocate non-absolute symbols by the
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section offset. */
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if (sym->section != &bfd_abs_section)
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symaddr += offset;
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sectinfo->sections[special_local_sect] = symaddr;
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/* The special local symbols don't go in the
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minimal symbol table, so ignore this one. */
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continue;
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}
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/* Not a special stabs-in-elf symbol, do regular
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symbol processing. */
|
||
if (sym->section->flags & SEC_LOAD)
|
||
{
|
||
ms_type = mst_file_data;
|
||
}
|
||
else
|
||
{
|
||
ms_type = mst_file_bss;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
ms_type = mst_unknown;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* FIXME: Solaris2 shared libraries include lots of
|
||
odd "absolute" and "undefined" symbols, that play
|
||
hob with actions like finding what function the PC
|
||
is in. Ignore them if they aren't text, data, or bss. */
|
||
/* ms_type = mst_unknown; */
|
||
continue; /* Skip this symbol. */
|
||
}
|
||
msym = record_minimal_symbol
|
||
(sym->name, strlen (sym->name), copy_names, symaddr,
|
||
ms_type, sym->section, objfile);
|
||
|
||
if (msym)
|
||
{
|
||
/* Pass symbol size field in via BFD. FIXME!!! */
|
||
elf_symbol_type *elf_sym;
|
||
|
||
/* NOTE: uweigand-20071112: A synthetic symbol does not have an
|
||
ELF-private part. However, in some cases (e.g. synthetic
|
||
'dot' symbols on ppc64) the udata.p entry is set to point back
|
||
to the original ELF symbol it was derived from. Get the size
|
||
from that symbol. */
|
||
if (type != ST_SYNTHETIC)
|
||
elf_sym = (elf_symbol_type *) sym;
|
||
else
|
||
elf_sym = (elf_symbol_type *) sym->udata.p;
|
||
|
||
if (elf_sym)
|
||
MSYMBOL_SIZE(msym) = elf_sym->internal_elf_sym.st_size;
|
||
|
||
msym->filename = filesymname;
|
||
gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
|
||
}
|
||
|
||
/* For @plt symbols, also record a trampoline to the
|
||
destination symbol. The @plt symbol will be used in
|
||
disassembly, and the trampoline will be used when we are
|
||
trying to find the target. */
|
||
if (msym && ms_type == mst_text && type == ST_SYNTHETIC)
|
||
{
|
||
int len = strlen (sym->name);
|
||
|
||
if (len > 4 && strcmp (sym->name + len - 4, "@plt") == 0)
|
||
{
|
||
struct minimal_symbol *mtramp;
|
||
|
||
mtramp = record_minimal_symbol (sym->name, len - 4, 1,
|
||
symaddr,
|
||
mst_solib_trampoline,
|
||
sym->section, objfile);
|
||
if (mtramp)
|
||
{
|
||
MSYMBOL_SIZE (mtramp) = MSYMBOL_SIZE (msym);
|
||
mtramp->filename = filesymname;
|
||
gdbarch_elf_make_msymbol_special (gdbarch, sym, mtramp);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Scan and build partial symbols for a symbol file.
|
||
We have been initialized by a call to elf_symfile_init, which
|
||
currently does nothing.
|
||
|
||
SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
|
||
in each section. We simplify it down to a single offset for all
|
||
symbols. FIXME.
|
||
|
||
MAINLINE is true if we are reading the main symbol
|
||
table (as opposed to a shared lib or dynamically loaded file).
|
||
|
||
This function only does the minimum work necessary for letting the
|
||
user "name" things symbolically; it does not read the entire symtab.
|
||
Instead, it reads the external and static symbols and puts them in partial
|
||
symbol tables. When more extensive information is requested of a
|
||
file, the corresponding partial symbol table is mutated into a full
|
||
fledged symbol table by going back and reading the symbols
|
||
for real.
|
||
|
||
We look for sections with specific names, to tell us what debug
|
||
format to look for: FIXME!!!
|
||
|
||
elfstab_build_psymtabs() handles STABS symbols;
|
||
mdebug_build_psymtabs() handles ECOFF debugging information.
|
||
|
||
Note that ELF files have a "minimal" symbol table, which looks a lot
|
||
like a COFF symbol table, but has only the minimal information necessary
|
||
for linking. We process this also, and use the information to
|
||
build gdb's minimal symbol table. This gives us some minimal debugging
|
||
capability even for files compiled without -g. */
|
||
|
||
static void
|
||
elf_symfile_read (struct objfile *objfile, int mainline)
|
||
{
|
||
bfd *abfd = objfile->obfd;
|
||
struct elfinfo ei;
|
||
struct cleanup *back_to;
|
||
CORE_ADDR offset;
|
||
long symcount = 0, dynsymcount = 0, synthcount, storage_needed;
|
||
asymbol **symbol_table = NULL, **dyn_symbol_table = NULL;
|
||
asymbol *synthsyms;
|
||
|
||
init_minimal_symbol_collection ();
|
||
back_to = make_cleanup_discard_minimal_symbols ();
|
||
|
||
memset ((char *) &ei, 0, sizeof (ei));
|
||
|
||
/* Allocate struct to keep track of the symfile */
|
||
objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *)
|
||
xmalloc (sizeof (struct dbx_symfile_info));
|
||
memset ((char *) objfile->deprecated_sym_stab_info, 0, sizeof (struct dbx_symfile_info));
|
||
make_cleanup (free_elfinfo, (void *) objfile);
|
||
|
||
/* Process the normal ELF symbol table first. This may write some
|
||
chain of info into the dbx_symfile_info in objfile->deprecated_sym_stab_info,
|
||
which can later be used by elfstab_offset_sections. */
|
||
|
||
storage_needed = bfd_get_symtab_upper_bound (objfile->obfd);
|
||
if (storage_needed < 0)
|
||
error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
if (storage_needed > 0)
|
||
{
|
||
symbol_table = (asymbol **) xmalloc (storage_needed);
|
||
make_cleanup (xfree, symbol_table);
|
||
symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table);
|
||
|
||
if (symcount < 0)
|
||
error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table, 0);
|
||
}
|
||
|
||
/* Add the dynamic symbols. */
|
||
|
||
storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd);
|
||
|
||
if (storage_needed > 0)
|
||
{
|
||
dyn_symbol_table = (asymbol **) xmalloc (storage_needed);
|
||
make_cleanup (xfree, dyn_symbol_table);
|
||
dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd,
|
||
dyn_symbol_table);
|
||
|
||
if (dynsymcount < 0)
|
||
error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
|
||
bfd_errmsg (bfd_get_error ()));
|
||
|
||
elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table, 0);
|
||
}
|
||
|
||
/* Add synthetic symbols - for instance, names for any PLT entries. */
|
||
|
||
synthcount = bfd_get_synthetic_symtab (abfd, symcount, symbol_table,
|
||
dynsymcount, dyn_symbol_table,
|
||
&synthsyms);
|
||
if (synthcount > 0)
|
||
{
|
||
asymbol **synth_symbol_table;
|
||
long i;
|
||
|
||
make_cleanup (xfree, synthsyms);
|
||
synth_symbol_table = xmalloc (sizeof (asymbol *) * synthcount);
|
||
for (i = 0; i < synthcount; i++)
|
||
synth_symbol_table[i] = synthsyms + i;
|
||
make_cleanup (xfree, synth_symbol_table);
|
||
elf_symtab_read (objfile, ST_SYNTHETIC, synthcount, synth_symbol_table, 1);
|
||
}
|
||
|
||
/* Install any minimal symbols that have been collected as the current
|
||
minimal symbols for this objfile. The debug readers below this point
|
||
should not generate new minimal symbols; if they do it's their
|
||
responsibility to install them. "mdebug" appears to be the only one
|
||
which will do this. */
|
||
|
||
install_minimal_symbols (objfile);
|
||
do_cleanups (back_to);
|
||
|
||
/* Now process debugging information, which is contained in
|
||
special ELF sections. */
|
||
|
||
/* If we are reinitializing, or if we have never loaded syms yet,
|
||
set table to empty. MAINLINE is cleared so that *_read_psymtab
|
||
functions do not all also re-initialize the psymbol table. */
|
||
if (mainline)
|
||
{
|
||
init_psymbol_list (objfile, 0);
|
||
mainline = 0;
|
||
}
|
||
|
||
/* We first have to find them... */
|
||
bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei);
|
||
|
||
/* ELF debugging information is inserted into the psymtab in the
|
||
order of least informative first - most informative last. Since
|
||
the psymtab table is searched `most recent insertion first' this
|
||
increases the probability that more detailed debug information
|
||
for a section is found.
|
||
|
||
For instance, an object file might contain both .mdebug (XCOFF)
|
||
and .debug_info (DWARF2) sections then .mdebug is inserted first
|
||
(searched last) and DWARF2 is inserted last (searched first). If
|
||
we don't do this then the XCOFF info is found first - for code in
|
||
an included file XCOFF info is useless. */
|
||
|
||
if (ei.mdebugsect)
|
||
{
|
||
const struct ecoff_debug_swap *swap;
|
||
|
||
/* .mdebug section, presumably holding ECOFF debugging
|
||
information. */
|
||
swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap;
|
||
if (swap)
|
||
elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect);
|
||
}
|
||
if (ei.stabsect)
|
||
{
|
||
asection *str_sect;
|
||
|
||
/* Stab sections have an associated string table that looks like
|
||
a separate section. */
|
||
str_sect = bfd_get_section_by_name (abfd, ".stabstr");
|
||
|
||
/* FIXME should probably warn about a stab section without a stabstr. */
|
||
if (str_sect)
|
||
elfstab_build_psymtabs (objfile,
|
||
ei.stabsect,
|
||
str_sect->filepos,
|
||
bfd_section_size (abfd, str_sect));
|
||
}
|
||
if (dwarf2_has_info (objfile))
|
||
{
|
||
/* DWARF 2 sections */
|
||
dwarf2_build_psymtabs (objfile);
|
||
}
|
||
|
||
/* FIXME: kettenis/20030504: This still needs to be integrated with
|
||
dwarf2read.c in a better way. */
|
||
dwarf2_build_frame_info (objfile);
|
||
}
|
||
|
||
/* This cleans up the objfile's deprecated_sym_stab_info pointer, and
|
||
the chain of stab_section_info's, that might be dangling from
|
||
it. */
|
||
|
||
static void
|
||
free_elfinfo (void *objp)
|
||
{
|
||
struct objfile *objfile = (struct objfile *) objp;
|
||
struct dbx_symfile_info *dbxinfo = objfile->deprecated_sym_stab_info;
|
||
struct stab_section_info *ssi, *nssi;
|
||
|
||
ssi = dbxinfo->stab_section_info;
|
||
while (ssi)
|
||
{
|
||
nssi = ssi->next;
|
||
xfree (ssi);
|
||
ssi = nssi;
|
||
}
|
||
|
||
dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */
|
||
}
|
||
|
||
|
||
/* Initialize anything that needs initializing when a completely new symbol
|
||
file is specified (not just adding some symbols from another file, e.g. a
|
||
shared library).
|
||
|
||
We reinitialize buildsym, since we may be reading stabs from an ELF file. */
|
||
|
||
static void
|
||
elf_new_init (struct objfile *ignore)
|
||
{
|
||
stabsread_new_init ();
|
||
buildsym_new_init ();
|
||
}
|
||
|
||
/* Perform any local cleanups required when we are done with a particular
|
||
objfile. I.E, we are in the process of discarding all symbol information
|
||
for an objfile, freeing up all memory held for it, and unlinking the
|
||
objfile struct from the global list of known objfiles. */
|
||
|
||
static void
|
||
elf_symfile_finish (struct objfile *objfile)
|
||
{
|
||
if (objfile->deprecated_sym_stab_info != NULL)
|
||
{
|
||
xfree (objfile->deprecated_sym_stab_info);
|
||
}
|
||
|
||
dwarf2_free_objfile (objfile);
|
||
}
|
||
|
||
/* ELF specific initialization routine for reading symbols.
|
||
|
||
It is passed a pointer to a struct sym_fns which contains, among other
|
||
things, the BFD for the file whose symbols are being read, and a slot for
|
||
a pointer to "private data" which we can fill with goodies.
|
||
|
||
For now at least, we have nothing in particular to do, so this function is
|
||
just a stub. */
|
||
|
||
static void
|
||
elf_symfile_init (struct objfile *objfile)
|
||
{
|
||
/* ELF objects may be reordered, so set OBJF_REORDERED. If we
|
||
find this causes a significant slowdown in gdb then we could
|
||
set it in the debug symbol readers only when necessary. */
|
||
objfile->flags |= OBJF_REORDERED;
|
||
}
|
||
|
||
/* When handling an ELF file that contains Sun STABS debug info,
|
||
some of the debug info is relative to the particular chunk of the
|
||
section that was generated in its individual .o file. E.g.
|
||
offsets to static variables are relative to the start of the data
|
||
segment *for that module before linking*. This information is
|
||
painfully squirreled away in the ELF symbol table as local symbols
|
||
with wierd names. Go get 'em when needed. */
|
||
|
||
void
|
||
elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst)
|
||
{
|
||
char *filename = pst->filename;
|
||
struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
|
||
struct stab_section_info *maybe = dbx->stab_section_info;
|
||
struct stab_section_info *questionable = 0;
|
||
int i;
|
||
char *p;
|
||
|
||
/* The ELF symbol info doesn't include path names, so strip the path
|
||
(if any) from the psymtab filename. */
|
||
while (0 != (p = strchr (filename, '/')))
|
||
filename = p + 1;
|
||
|
||
/* FIXME: This linear search could speed up significantly
|
||
if it was chained in the right order to match how we search it,
|
||
and if we unchained when we found a match. */
|
||
for (; maybe; maybe = maybe->next)
|
||
{
|
||
if (filename[0] == maybe->filename[0]
|
||
&& strcmp (filename, maybe->filename) == 0)
|
||
{
|
||
/* We found a match. But there might be several source files
|
||
(from different directories) with the same name. */
|
||
if (0 == maybe->found)
|
||
break;
|
||
questionable = maybe; /* Might use it later. */
|
||
}
|
||
}
|
||
|
||
if (maybe == 0 && questionable != 0)
|
||
{
|
||
complaint (&symfile_complaints,
|
||
_("elf/stab section information questionable for %s"), filename);
|
||
maybe = questionable;
|
||
}
|
||
|
||
if (maybe)
|
||
{
|
||
/* Found it! Allocate a new psymtab struct, and fill it in. */
|
||
maybe->found++;
|
||
pst->section_offsets = (struct section_offsets *)
|
||
obstack_alloc (&objfile->objfile_obstack,
|
||
SIZEOF_N_SECTION_OFFSETS (objfile->num_sections));
|
||
for (i = 0; i < maybe->num_sections; i++)
|
||
(pst->section_offsets)->offsets[i] = maybe->sections[i];
|
||
return;
|
||
}
|
||
|
||
/* We were unable to find any offsets for this file. Complain. */
|
||
if (dbx->stab_section_info) /* If there *is* any info, */
|
||
complaint (&symfile_complaints,
|
||
_("elf/stab section information missing for %s"), filename);
|
||
}
|
||
|
||
/* Register that we are able to handle ELF object file formats. */
|
||
|
||
static struct sym_fns elf_sym_fns =
|
||
{
|
||
bfd_target_elf_flavour,
|
||
elf_new_init, /* sym_new_init: init anything gbl to entire symtab */
|
||
elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */
|
||
elf_symfile_read, /* sym_read: read a symbol file into symtab */
|
||
elf_symfile_finish, /* sym_finish: finished with file, cleanup */
|
||
default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */
|
||
elf_symfile_segments, /* sym_segments: Get segment information from
|
||
a file. */
|
||
NULL, /* sym_read_linetable */
|
||
NULL /* next: pointer to next struct sym_fns */
|
||
};
|
||
|
||
void
|
||
_initialize_elfread (void)
|
||
{
|
||
add_symtab_fns (&elf_sym_fns);
|
||
}
|