With a gdb build with --enable-targets=all we run into a KFAIL:
...
KFAIL: gdb.gdb/unittest.exp: executable loaded: maintenance selftest, \
failed none (PRMS: gdb/27891)
...
due to:
...
Running selftest print_one_insn.^M
Self test failed: arch armv8.1-m.main: self-test failed at \
disasm-selftests.c:165^M
...
The test fails because we expect disassembling of one arm insn to consume 4
bytes and produce (using verbose = true in disasm-selftests.c):
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arm mov r0, #0
...
but instead the disassembler uses thumb mode and only consumes 2
bytes and produces:
...
arm movs r0, r0
...
The failure does not show up in the "no executable loaded" variant because
this code in gdb_print_insn_arm isn't triggered:
...
if (current_program_space->exec_bfd () != NULL)
info->flags |= USER_SPECIFIED_MACHINE_TYPE;
...
and consequently we do this in print_insn:
...
if ((info->flags & USER_SPECIFIED_MACHINE_TYPE) == 0)
info->mach = bfd_mach_arm_unknown;
...
and don't set force_thumb to true in select_arm_features.
The code in gdb_print_insn_arm makes the assumption that the disassembly
architecture matches the exec architecture, which in this case is incorrect,
because the exec architecture is x86_64, and the disassembly architecture is
armv8.1-m.main. Fix that by explicitly checking it:
...
if (current_program_space->exec_bfd () != NULL
&& (current_program_space->exec_bfd ()->arch_info
== gdbarch_bfd_arch_info (gdbarch)))
...
This fixes the print_one_insn failure, so remove the KFAIL.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27891
3047c7869d