From 26540402495f35d5f19762ceba66605bca8fa63b Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Sat, 7 Apr 2018 13:23:28 -0400 Subject: 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. --- gdb/arch-utils.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'gdb/arch-utils.c') diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 2ff0f4d..5986ed6 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -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); -- cgit v1.1