Make "set osabi none" really work (PR 22980)

I was looking for a way to reproduce easily PR 22979 by doing this:

  (gdb) set architecture i386:x86-64
  (gdb) set osabi none

However, I noticed that even though I did "set osabi none", the gdbarch
gdb created was for Linux:

  (gdb) set debug arch 1
  (gdb) set architecture i386:x86-64
  ...
  (gdb) set osabi none
  gdbarch_find_by_info: info.bfd_arch_info i386:x86-64
  gdbarch_find_by_info: info.byte_order 1 (little)
  gdbarch_find_by_info: info.osabi 4 (GNU/Linux)  <--- Wrong?
  gdbarch_find_by_info: info.abfd 0x0
  gdbarch_find_by_info: info.tdep_info 0x0
  gdbarch_find_by_info: Previous architecture 0x1e6fd30 (i386:x86-64)
  selected
  gdbarch_update_p: Architecture 0x1e6fd30 (i386:x86-64) unchanged

This is because the value GDB_OSABI_UNKNOWN has an unclear role,
sometimes meaning "no osabi" and sometimes "please selected
automatically".  Doing "set osabi none" sets the requested osabi to
GDB_OSABI_UNKNOWN, in which case gdbarch_info_fill overrides it with a
value from the target description, or the built-in default osabi.  This
means that it's impossible to force GDB not to use an osabi with "set
osabi".  Since my GDB's built-in default osabi is Linux, it always falls
back to GDB_OSABI_LINUX.

To fix it, I introduced GDB_OSABI_NONE, which really means "I don't want
any osabi".  GDB_OSABI_UNKNOWN can then be used only for "not set yet,
please auto-detect".  GDB_OSABI_UNINITIALIZED now seems unnecessary
since it overlaps with GDB_OSABI_UNKNOWN, so I think it can be removed
and gdbarch_info::osabi can be initialized to GDB_OSABI_UNKNOWN.

gdb/ChangeLog:

	PR gdb/22980
	* defs.h (enum gdb_osabi): Remove GDB_OSABI_UNINITIALIZED, add
	GDB_OSABI_NONE.
	* arch-utils.c (gdbarch_info_init): Don't set info->osabi.
	* osabi.c (gdb_osabi_names): Add "unknown" entry.

gdb/testsuite/ChangeLog:

	PR gdb/22980
	* gdb.base/osabi.exp: New file.
This commit is contained in:
Simon Marchi 2018-04-07 13:23:28 -04:00 committed by Simon Marchi
parent 9018be22e0
commit 2654040249
6 changed files with 50 additions and 11 deletions

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@ -1,3 +1,11 @@
2018-04-07 Simon Marchi <simon.marchi@ericsson.com>
PR gdb/22980
* defs.h (enum gdb_osabi): Remove GDB_OSABI_UNINITIALIZED, add
GDB_OSABI_NONE.
* arch-utils.c (gdbarch_info_init): Don't set info->osabi.
* osabi.c (gdb_osabi_names): Add "unknown" entry.
2018-04-07 Simon Marchi <simon.marchi@ericsson.com>
* common/byte-vector.h (char_vector): New type.

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@ -727,7 +727,6 @@ gdbarch_info_init (struct gdbarch_info *info)
memset (info, 0, sizeof (struct gdbarch_info));
info->byte_order = BFD_ENDIAN_UNKNOWN;
info->byte_order_for_code = info->byte_order;
info->osabi = GDB_OSABI_UNINITIALIZED;
}
/* Similar to init, but this time fill in the blanks. Information is
@ -772,9 +771,10 @@ gdbarch_info_fill (struct gdbarch_info *info)
/* "(gdb) set osabi ...". Handled by gdbarch_lookup_osabi. */
/* From the manual override, or from file. */
if (info->osabi == GDB_OSABI_UNINITIALIZED)
if (info->osabi == GDB_OSABI_UNKNOWN)
info->osabi = gdbarch_lookup_osabi (info->abfd);
/* From the target. */
if (info->osabi == GDB_OSABI_UNKNOWN && info->target_desc != NULL)
info->osabi = tdesc_osabi (info->target_desc);
/* From the configured default. */
@ -782,6 +782,9 @@ gdbarch_info_fill (struct gdbarch_info *info)
if (info->osabi == GDB_OSABI_UNKNOWN)
info->osabi = GDB_OSABI_DEFAULT;
#endif
/* If we still don't know which osabi to pick, pick none. */
if (info->osabi == GDB_OSABI_UNKNOWN)
info->osabi = GDB_OSABI_NONE;
/* Must have at least filled in the architecture. */
gdb_assert (info->bfd_arch_info != NULL);

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@ -482,9 +482,8 @@ extern int longest_to_int (LONGEST);
table in osabi.c. */
enum gdb_osabi
{
GDB_OSABI_UNINITIALIZED = -1, /* For struct gdbarch_info. */
GDB_OSABI_UNKNOWN = 0, /* keep this zero */
GDB_OSABI_NONE,
GDB_OSABI_SVR4,
GDB_OSABI_HURD,

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@ -58,6 +58,7 @@ struct osabi_names
them in sync. */
static const struct osabi_names gdb_osabi_names[] =
{
{ "unknown", NULL },
{ "none", NULL },
{ "SVR4", NULL },
@ -335,9 +336,11 @@ gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdb_osabi_handler *handler;
if (info.osabi == GDB_OSABI_UNKNOWN)
gdb_assert (info.osabi != GDB_OSABI_UNKNOWN);
if (info.osabi == GDB_OSABI_NONE)
{
/* Don't complain about an unknown OSABI. Assume the user knows
/* Don't complain about no OSABI. Assume the user knows
what they are doing. */
return;
}
@ -603,11 +606,6 @@ set_osabi (const char *args, int from_tty, struct cmd_list_element *c)
user_selected_osabi = GDB_OSABI_DEFAULT;
user_osabi_state = osabi_user;
}
else if (strcmp (set_osabi_string, "none") == 0)
{
user_selected_osabi = GDB_OSABI_UNKNOWN;
user_osabi_state = osabi_user;
}
else
{
int i;

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@ -1,3 +1,8 @@
2018-04-07 Simon Marchi <simon.marchi@ericsson.com>
PR gdb/22980
* gdb.base/osabi.exp: New file.
2018-04-02 Weimin Pan <weimin.pan@oracle.com>
* gdb.cp/static-typedef-print.exp: New file.

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@ -0,0 +1,26 @@
# Copyright (C) 2018 Free Software Foundation, Inc.
# 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 3 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, see <http://www.gnu.org/licenses/>.
# This file is part of the gdb testsuite.
# Test that choosing "set osabi none" really requests a gdbarch with no osabi.
proc test_set_osabi_none { } {
clean_restart
gdb_test_no_output "set debug arch 1"
gdb_test "set osabi none" ".*gdbarch_find_by_info: info.osabi 1 \\(none\\).*"
}
test_set_osabi_none