binutils-gdb/gdb/osabi.c
2002-07-27 01:28:43 +00:00

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/* OS ABI variant handling for GDB.
Copyright 2001, 2002 Free Software Foundation, Inc.
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
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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. */
#include "defs.h"
#include "osabi.h"
#include "elf-bfd.h"
/* This table matches the indices assigned to enum gdb_osabi. Keep
them in sync. */
static const char * const gdb_osabi_names[] =
{
"<unknown>",
"SVR4",
"GNU/Hurd",
"Solaris",
"OSF/1",
"GNU/Linux",
"FreeBSD a.out",
"FreeBSD ELF",
"NetBSD a.out",
"NetBSD ELF",
"Windows CE",
"DJGPP",
"NetWare",
"Irix",
"LynxOS",
"ARM EABI v1",
"ARM EABI v2",
"ARM APCS",
"<invalid>"
};
const char *
gdbarch_osabi_name (enum gdb_osabi osabi)
{
if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
return gdb_osabi_names[osabi];
return gdb_osabi_names[GDB_OSABI_INVALID];
}
/* Handler for a given architecture/OS ABI pair. There should be only
one handler for a given OS ABI each architecture family. */
struct gdb_osabi_handler
{
struct gdb_osabi_handler *next;
enum bfd_architecture arch;
enum gdb_osabi osabi;
void (*init_osabi)(struct gdbarch_info, struct gdbarch *);
};
static struct gdb_osabi_handler *gdb_osabi_handler_list;
void
gdbarch_register_osabi (enum bfd_architecture arch, enum gdb_osabi osabi,
void (*init_osabi)(struct gdbarch_info,
struct gdbarch *))
{
struct gdb_osabi_handler **handler_p;
/* Registering an OS ABI handler for "unknown" is not allowed. */
if (osabi == GDB_OSABI_UNKNOWN)
{
internal_error
(__FILE__, __LINE__,
"gdbarch_register_osabi: An attempt to register a handler for "
"OS ABI \"%s\" for architecture %s was made. The handler will "
"not be registered",
gdbarch_osabi_name (osabi),
bfd_printable_arch_mach (arch, 0));
return;
}
for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL;
handler_p = &(*handler_p)->next)
{
if ((*handler_p)->arch == arch
&& (*handler_p)->osabi == osabi)
{
internal_error
(__FILE__, __LINE__,
"gdbarch_register_osabi: A handler for OS ABI \"%s\" "
"has already been registered for architecture %s",
gdbarch_osabi_name (osabi),
bfd_printable_arch_mach (arch, 0));
/* If user wants to continue, override previous definition. */
(*handler_p)->init_osabi = init_osabi;
return;
}
}
(*handler_p)
= (struct gdb_osabi_handler *) xmalloc (sizeof (struct gdb_osabi_handler));
(*handler_p)->next = NULL;
(*handler_p)->arch = arch;
(*handler_p)->osabi = osabi;
(*handler_p)->init_osabi = init_osabi;
}
/* Sniffer to find the OS ABI for a given file's architecture and flavour.
It is legal to have multiple sniffers for each arch/flavour pair, to
disambiguate one OS's a.out from another, for example. The first sniffer
to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
be careful to claim a file only if it knows for sure what it is. */
struct gdb_osabi_sniffer
{
struct gdb_osabi_sniffer *next;
enum bfd_architecture arch; /* bfd_arch_unknown == wildcard */
enum bfd_flavour flavour;
enum gdb_osabi (*sniffer)(bfd *);
};
static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list;
void
gdbarch_register_osabi_sniffer (enum bfd_architecture arch,
enum bfd_flavour flavour,
enum gdb_osabi (*sniffer_fn)(bfd *))
{
struct gdb_osabi_sniffer *sniffer;
sniffer =
(struct gdb_osabi_sniffer *) xmalloc (sizeof (struct gdb_osabi_sniffer));
sniffer->arch = arch;
sniffer->flavour = flavour;
sniffer->sniffer = sniffer_fn;
sniffer->next = gdb_osabi_sniffer_list;
gdb_osabi_sniffer_list = sniffer;
}
enum gdb_osabi
gdbarch_lookup_osabi (bfd *abfd)
{
struct gdb_osabi_sniffer *sniffer;
enum gdb_osabi osabi, match;
int match_specific;
match = GDB_OSABI_UNKNOWN;
match_specific = 0;
for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL;
sniffer = sniffer->next)
{
if ((sniffer->arch == bfd_arch_unknown /* wildcard */
|| sniffer->arch == bfd_get_arch (abfd))
&& sniffer->flavour == bfd_get_flavour (abfd))
{
osabi = (*sniffer->sniffer) (abfd);
if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID)
{
internal_error
(__FILE__, __LINE__,
"gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
"for architecture %s flavour %d",
(int) osabi,
bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
(int) bfd_get_flavour (abfd));
}
else if (osabi != GDB_OSABI_UNKNOWN)
{
/* A specific sniffer always overrides a generic sniffer.
Croak on multiple match if the two matches are of the
same class. If the user wishes to continue, we'll use
the first match. */
if (match != GDB_OSABI_UNKNOWN)
{
if ((match_specific && sniffer->arch != bfd_arch_unknown)
|| (!match_specific && sniffer->arch == bfd_arch_unknown))
{
internal_error
(__FILE__, __LINE__,
"gdbarch_lookup_osabi: multiple %sspecific OS ABI "
"match for architecture %s flavour %d: first "
"match \"%s\", second match \"%s\"",
match_specific ? "" : "non-",
bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
(int) bfd_get_flavour (abfd),
gdbarch_osabi_name (match),
gdbarch_osabi_name (osabi));
}
else if (sniffer->arch != bfd_arch_unknown)
{
match = osabi;
match_specific = 1;
}
}
else
{
match = osabi;
if (sniffer->arch != bfd_arch_unknown)
match_specific = 1;
}
}
}
}
return match;
}
void
gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch,
enum gdb_osabi osabi)
{
struct gdb_osabi_handler *handler;
bfd *abfd = info.abfd;
const struct bfd_arch_info *arch_info = gdbarch_bfd_arch_info (gdbarch);
if (osabi == GDB_OSABI_UNKNOWN)
{
/* Don't complain about not knowing the OS ABI if we don't
have an inferior. */
if (info.abfd)
fprintf_filtered
(gdb_stderr, "GDB doesn't recognize the OS ABI of the inferior. "
"Attempting to continue with the default %s settings",
bfd_printable_arch_mach (arch_info->arch, arch_info->mach));
return;
}
for (handler = gdb_osabi_handler_list; handler != NULL;
handler = handler->next)
{
if (handler->arch == bfd_get_arch (abfd)
&& handler->osabi == osabi)
{
(*handler->init_osabi) (info, gdbarch);
return;
}
}
/* We assume that if GDB_MULTI_ARCH is less than GDB_MULTI_ARCH_TM
that an ABI variant can be supported by overriding definitions in
the tm-file. */
if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL)
fprintf_filtered
(gdb_stderr,
"A handler for the OS ABI \"%s\" is not built into this "
"configuration of GDB. "
"Attempting to continue with the default %s settings",
gdbarch_osabi_name (osabi),
bfd_printable_arch_mach (arch_info->arch, arch_info->mach));
}
/* Generic sniffer for ELF flavoured files. */
void
generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, void *obj)
{
enum gdb_osabi *os_ident_ptr = obj;
const char *name;
unsigned int sectsize;
name = bfd_get_section_name (abfd, sect);
sectsize = bfd_section_size (abfd, sect);
/* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
if (strcmp (name, ".note.ABI-tag") == 0 && sectsize > 0)
{
unsigned int name_length, data_length, note_type;
char *note;
/* If the section is larger than this, it's probably not what we are
looking for. */
if (sectsize > 128)
sectsize = 128;
note = alloca (sectsize);
bfd_get_section_contents (abfd, sect, note,
(file_ptr) 0, (bfd_size_type) sectsize);
name_length = bfd_h_get_32 (abfd, note);
data_length = bfd_h_get_32 (abfd, note + 4);
note_type = bfd_h_get_32 (abfd, note + 8);
if (name_length == 4 && data_length == 16 && note_type == NT_GNU_ABI_TAG
&& strcmp (note + 12, "GNU") == 0)
{
int os_number = bfd_h_get_32 (abfd, note + 16);
switch (os_number)
{
case GNU_ABI_TAG_LINUX:
*os_ident_ptr = GDB_OSABI_LINUX;
break;
case GNU_ABI_TAG_HURD:
*os_ident_ptr = GDB_OSABI_HURD;
break;
case GNU_ABI_TAG_SOLARIS:
*os_ident_ptr = GDB_OSABI_SOLARIS;
break;
default:
internal_error
(__FILE__, __LINE__,
"generic_elf_osabi_sniff_abi_tag_sections: unknown OS number %d",
os_number);
}
return;
}
else if (name_length == 8 && data_length == 4
&& note_type == NT_FREEBSD_ABI_TAG
&& strcmp (note + 12, "FreeBSD") == 0)
{
/* XXX Should we check the version here? Probably not
necessary yet. */
*os_ident_ptr = GDB_OSABI_FREEBSD_ELF;
}
return;
}
/* .note.netbsd.ident notes, used by NetBSD. */
if (strcmp (name, ".note.netbsd.ident") == 0 && sectsize > 0)
{
unsigned int name_length, data_length, note_type;
char *note;
/* If the section is larger than this, it's probably not what we are
looking for. */
if (sectsize > 128)
sectsize = 128;
note = alloca (sectsize);
bfd_get_section_contents (abfd, sect, note,
(file_ptr) 0, (bfd_size_type) sectsize);
name_length = bfd_h_get_32 (abfd, note);
data_length = bfd_h_get_32 (abfd, note + 4);
note_type = bfd_h_get_32 (abfd, note + 8);
if (name_length == 7 && data_length == 4 && note_type == NT_NETBSD_IDENT
&& strcmp (note + 12, "NetBSD") == 0)
{
/* XXX Should we check the version here? Probably not
necessary yet. */
*os_ident_ptr = GDB_OSABI_NETBSD_ELF;
}
return;
}
}
static enum gdb_osabi
generic_elf_osabi_sniffer (bfd *abfd)
{
unsigned int elfosabi;
enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
switch (elfosabi)
{
case ELFOSABI_NONE:
/* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the
file are conforming to the base specification for that machine
(there are no OS-specific extensions). In order to determine the
real OS in use we must look for OS notes that have been added. */
bfd_map_over_sections (abfd,
generic_elf_osabi_sniff_abi_tag_sections,
&osabi);
break;
case ELFOSABI_FREEBSD:
osabi = GDB_OSABI_FREEBSD_ELF;
break;
case ELFOSABI_NETBSD:
osabi = GDB_OSABI_NETBSD_ELF;
break;
case ELFOSABI_LINUX:
osabi = GDB_OSABI_LINUX;
break;
case ELFOSABI_HURD:
osabi = GDB_OSABI_HURD;
break;
case ELFOSABI_SOLARIS:
osabi = GDB_OSABI_SOLARIS;
break;
}
if (osabi == GDB_OSABI_UNKNOWN)
{
/* The FreeBSD folks have been naughty; they stored the string
"FreeBSD" in the padding of the e_ident field of the ELF
header to "brand" their ELF binaries in FreeBSD 3.x. */
if (strcmp (&elf_elfheader (abfd)->e_ident[8], "FreeBSD") == 0)
osabi = GDB_OSABI_FREEBSD_ELF;
}
return osabi;
}
void
_initialize_gdb_osabi (void)
{
if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID], "<invalid>") != 0)
internal_error
(__FILE__, __LINE__,
"_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent");
/* Register a generic sniffer for ELF flavoured files. */
gdbarch_register_osabi_sniffer (bfd_arch_unknown,
bfd_target_elf_flavour,
generic_elf_osabi_sniffer);
}