Hello Markus,
This is OK with a few minor changes pointed out below.
On 04/09/2018 03:19 PM, Metzger, Markus T wrote:
> diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
> index 5986ed6..77b370c 100644
> --- a/gdb/arch-utils.c
> +++ b/gdb/arch-utils.c
> @@ -979,6 +979,13 @@ gdbarch_skip_prologue_noexcept (gdbarch *gdbarch, CORE_ADDR pc) noexcept
> return new_pc;
> }
>
> +/* See arch-utils.h. */
> +
> +bool default_in_indirect_branch_thunk (gdbarch *gdbarch, CORE_ADDR pc)
Line break after "bool".
> +{
> + return false;
> +}
> +
> void
> _initialize_gdbarch_utils (void)
> {
> --- a/gdb/gdbarch.sh
> +++ b/gdb/gdbarch.sh
> @@ -660,6 +660,9 @@ m;CORE_ADDR;skip_solib_resolver;CORE_ADDR pc;pc;;generic_skip_solib_resolver;;0
> # Some systems also have trampoline code for returning from shared libs.
> m;int;in_solib_return_trampoline;CORE_ADDR pc, const char *name;pc, name;;generic_in_solib_return_trampoline;;0
>
> +# Return true if PC lies inside an indirect branch thunk.
> +m;bool;in_indirect_branch_thunk;CORE_ADDR pc;pc;;default_in_indirect_branch_thunk;;0
If that last 0 is the default (I never remember off hand), then please write
"false" instead. Assuming that works.
> diff --git a/gdb/testsuite/gdb.base/step-indirect-call-thunk.exp b/gdb/testsuite/gdb.base/step-indirect-call-thunk.exp
> new file mode 100644
> index 0000000..7f9ab60
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/step-indirect-call-thunk.exp
> @@ -0,0 +1,61 @@
> +# Copyright 2018 Free Software Foundation, Inc.
> +
...
> +
> +proc stepi_until { current target test } {
Please add a describing comment, particularly what
the parameters mean.
> + global gdb_prompt
> +
> + gdb_test_multiple "stepi" "$test: stepi" {
> + -re "$current.*$gdb_prompt $" {
> + send_gdb "stepi\n"
> + exp_continue
This should probably have some upper bound.
> + }
> + -re "$target.*$gdb_prompt $" {
> + pass "$test: $target reached"
> + }
> + -re "$gdb_prompt $" {
> + fail "$test: $target not reached"
> + }
It's better for result diffing, buildbot, etc. if FAIL/PASS
have the same test message. And with that, the "fail" case
won't be necessary, since it's already taken care of by
gdb_test_multiple. See below.
> + timeout {
> + fail "$test: timeout"
> + }
A timeout handler is usually not needed because
gdb_test_multiple already handles it.
So that leaves you with something like this, with
upper bound for steps added while at it:
set step_count 0
set test "stepi until target"
gdb_test_multiple "stepi" $test {
-re "$current.*$gdb_prompt $" {
send_gdb "stepi\n"
# Cap number of steps just in case we end up
# stuck in an infinite loop.
incr step_count
if {$step_count < 100} {
exp_continue
} else {
fail $test
}
}
-re "$target.*$gdb_prompt $" {
pass $test
}
}
Same comments apply to step_until in the other test file.
> +++ b/gdb/x86-tdep.c
> @@ -0,0 +1,75 @@
> +/* Target-dependent code for X86-based targets.
> +
> + Copyright (C) 2018 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 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/>. */
> +
> +#include "x86-tdep.h"
"defs.h" should be included here, at the top, instead of ...
> +++ b/gdb/x86-tdep.h
> @@ -0,0 +1,32 @@
> +
> +#ifndef X86_TDEP_H
> +#define X86_TDEP_H
> +
> +#include "defs.h"
> +
... here.
See <https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#Include_Files>.
> +
> +bool
> +x86_in_indirect_branch_thunk (CORE_ADDR pc, const char **register_names,
> + int lo, int hi)
> +{
...
> + if (*name == 0)
Nit, we tend to write instead:
if (*name == '\0')
> +++ b/gdb/x86-tdep.h
> @@ -0,0 +1,32 @@
> +
> +#ifndef X86_TDEP_H
> +#define X86_TDEP_H
> +
> +#include "defs.h"
> +
Thanks,
Pedro Alves
@@ -44,7 +44,7 @@
#include "reggroups.h"
#include "osabi.h"
#include "gdb_obstack.h"
-#include "observable.h"
+#include "observer.h"
#include "regcache.h"
#include "objfiles.h"
#include "auxv.h"
@@ -5480,7 +5480,7 @@
gdb_assert (new_gdbarch != NULL);
gdb_assert (new_gdbarch->initialized_p);
current_inferior ()->gdbarch = new_gdbarch;
- gdb::observers::architecture_changed.notify (new_gdbarch);
+ observer_notify_architecture_changed (new_gdbarch);
registers_changed ();
}
, which result in a build error:
.../gdb/gdbarch.c:47:10: fatal error: observer.h: No such file or directory
#include "observer.h"
^~~~~~~~~~~~
compilation terminated.
I excluded those from my patch.
Regards,
Markus.
---
commit 9d4066a96c132ebc8c671e54dd26338f73a8cf18
Author: Markus Metzger <markus.t.metzger@intel.com>
Date: Wed Feb 14 14:30:57 2018 +0100
infrun: step through indirect branch thunks
With version 7.3 GCC supports new options
-mindirect-branch=<choice>
-mfunction-return=<choice>
The choices are:
keep behaves as before
thunk jumps through a thunk
thunk-external jumps through an external thunk
thunk-inline jumps through an inlined thunk
For thunk and thunk-external, GDB would, on a call to the thunk, step into
the thunk and then resume to its caller assuming that this is an
undebuggable function. On a return thunk, GDB would stop inside the
thunk.
Make GDB step through such thunks instead.
Before:
Temporary breakpoint 1, main ()
at gdb.base/step-indirect-call-thunk.c:37
37 x = apply (inc, 41);
(gdb) s
apply (op=0x80483e6 <inc>, x=41)
at gdb.base/step-indirect-call-thunk.c:29
29 return op (x);
(gdb)
30 }
After:
Temporary breakpoint 1, main ()
at gdb.base/step-indirect-call-thunk.c:37
37 x = apply (inc, 41);
(gdb) s
apply (op=0x80483e6 <inc>, x=41)
at gdb.base/step-indirect-call-thunk.c:29
29 return op (x);
(gdb)
inc (x=41) at gdb.base/step-indirect-call-thunk.c:23
23 return x + 1;
This is independent of the step-mode. In order to step into the thunk,
you would need to use stepi.
When stepping over an indirect call thunk, GDB would first step through
the thunk, then recognize that it stepped into a sub-routine and resume to
the caller (of the thunk). Not sure whether this is worth optimizing.
Thunk detection is implemented via gdbarch. I implemented the methods for
IA. Other architectures may run into unexpected fails.
The tests assume a fixed number of instruction steps to reach a thunk.
This depends on the compiler as well as the architecture. They may need
adjustments when we add support for more architectures. Or we can simply
drop those tests that cover being able to step into thunks using
instruction stepping.
When using an older GCC, the tests will fail to build and will be reported
as untested:
Running .../gdb.base/step-indirect-call-thunk.exp ...
gdb compile failed, \
gcc: error: unrecognized command line option '-mindirect-branch=thunk'
gcc: error: unrecognized command line option '-mfunction-return=thunk'
=== gdb Summary ===
# of untested testcases 1
2018-04-09 Markus Metzger <markus.t.metzger@intel.com>
gdb/
* infrun.c (process_event_stop_test):
Call gdbarch_in_indirect_branch_thunk.
* gdbarch.sh (in_indirect_branch_thunk): New.
* gdbarch.c: Regenerated.
* gdbarch.h: Regenerated.
* x86-tdep.h: New.
* x86-tdep.c: New.
* Makefile.in (ALL_TARGET_OBS): Add x86-tdep.o.
(HFILES_NO_SRCDIR): Add x86-tdep.h.
(ALLDEPFILES): Add x86-tdep.c.
* arch-utils.h (default_in_indirect_branch_thunk): New.
* arch-utils.c (default_in_indirect_branch_thunk): New.
* i386-tdep: Include x86-tdep.h.
(i386_in_indirect_branch_thunk): New.
(i386_elf_init_abi): Set in_indirect_branch_thunk gdbarch function.
* amd64-tdep: Include x86-tdep.h.
(amd64_in_indirect_branch_thunk): New.
(amd64_init_abi): Set in_indirect_branch_thunk gdbarch function.
testsuite/
* gdb.base/step-indirect-call-thunk.exp: New.
* gdb.base/step-indirect-call-thunk.c: New.
* gdb.reverse/step-indirect-call-thunk.exp: New.
* gdb.reverse/step-indirect-call-thunk.c: New.
@@ -792,6 +792,7 @@ ALL_TARGET_OBS = \
vax-nbsd-tdep.o \
vax-tdep.o \
windows-tdep.o \
+ x86-tdep.o \
xcoffread.o \
xstormy16-tdep.o \
xtensa-config.o \
@@ -1520,7 +1521,8 @@ HFILES_NO_SRCDIR = \
tui/tui-win.h \
tui/tui-windata.h \
tui/tui-wingeneral.h \
- tui/tui-winsource.h
+ tui/tui-winsource.h \
+ x86-tdep.h
# Header files that already have srcdir in them, or which are in objdir.
@@ -2362,6 +2364,7 @@ ALLDEPFILES = \
windows-nat.c \
windows-tdep.c \
x86-nat.c \
+ x86-tdep.c \
xcoffread.c \
xstormy16-tdep.c \
xtensa-config.c \
@@ -48,6 +48,7 @@
#include "ax-gdb.h"
#include "common/byte-vector.h"
#include "osabi.h"
+#include "x86-tdep.h"
/* Note that the AMD64 architecture was previously known as x86-64.
The latter is (forever) engraved into the canonical system name as
@@ -3034,6 +3035,16 @@ static const int amd64_record_regmap[] =
AMD64_DS_REGNUM, AMD64_ES_REGNUM, AMD64_FS_REGNUM, AMD64_GS_REGNUM
};
+/* Implement the "in_indirect_branch_thunk" gdbarch function. */
+
+static bool
+amd64_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ return x86_in_indirect_branch_thunk (pc, amd64_register_names,
+ AMD64_RAX_REGNUM,
+ AMD64_RIP_REGNUM);
+}
+
void
amd64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
const target_desc *default_tdesc)
@@ -3206,6 +3217,9 @@ amd64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
set_gdbarch_insn_is_call (gdbarch, amd64_insn_is_call);
set_gdbarch_insn_is_ret (gdbarch, amd64_insn_is_ret);
set_gdbarch_insn_is_jump (gdbarch, amd64_insn_is_jump);
+
+ set_gdbarch_in_indirect_branch_thunk (gdbarch,
+ amd64_in_indirect_branch_thunk);
}
/* Initialize ARCH for x86-64, no osabi. */
@@ -979,6 +979,13 @@ gdbarch_skip_prologue_noexcept (gdbarch *gdbarch, CORE_ADDR pc) noexcept
return new_pc;
}
+/* See arch-utils.h. */
+
+bool default_in_indirect_branch_thunk (gdbarch *gdbarch, CORE_ADDR pc)
+{
+ return false;
+}
+
void
_initialize_gdbarch_utils (void)
{
@@ -262,4 +262,9 @@ extern int default_print_insn (bfd_vma memaddr, disassemble_info *info);
extern CORE_ADDR gdbarch_skip_prologue_noexcept (gdbarch *gdbarch,
CORE_ADDR pc) noexcept;
+/* Default implementation of gdbarch_in_indirect_branch_thunk that returns
+ false. */
+extern bool default_in_indirect_branch_thunk (gdbarch *gdbarch,
+ CORE_ADDR pc);
+
#endif
@@ -266,6 +266,7 @@ struct gdbarch
gdbarch_skip_trampoline_code_ftype *skip_trampoline_code;
gdbarch_skip_solib_resolver_ftype *skip_solib_resolver;
gdbarch_in_solib_return_trampoline_ftype *in_solib_return_trampoline;
+ gdbarch_in_indirect_branch_thunk_ftype *in_indirect_branch_thunk;
gdbarch_stack_frame_destroyed_p_ftype *stack_frame_destroyed_p;
gdbarch_elf_make_msymbol_special_ftype *elf_make_msymbol_special;
gdbarch_coff_make_msymbol_special_ftype *coff_make_msymbol_special;
@@ -433,6 +434,7 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->skip_trampoline_code = generic_skip_trampoline_code;
gdbarch->skip_solib_resolver = generic_skip_solib_resolver;
gdbarch->in_solib_return_trampoline = generic_in_solib_return_trampoline;
+ gdbarch->in_indirect_branch_thunk = default_in_indirect_branch_thunk;
gdbarch->stack_frame_destroyed_p = generic_stack_frame_destroyed_p;
gdbarch->coff_make_msymbol_special = default_coff_make_msymbol_special;
gdbarch->make_symbol_special = default_make_symbol_special;
@@ -627,6 +629,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of skip_trampoline_code, invalid_p == 0 */
/* Skip verify of skip_solib_resolver, invalid_p == 0 */
/* Skip verify of in_solib_return_trampoline, invalid_p == 0 */
+ /* Skip verify of in_indirect_branch_thunk, invalid_p == 0 */
/* Skip verify of stack_frame_destroyed_p, invalid_p == 0 */
/* Skip verify of elf_make_msymbol_special, has predicate. */
/* Skip verify of coff_make_msymbol_special, invalid_p == 0 */
@@ -1103,6 +1106,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: have_nonsteppable_watchpoint = %s\n",
plongest (gdbarch->have_nonsteppable_watchpoint));
fprintf_unfiltered (file,
+ "gdbarch_dump: in_indirect_branch_thunk = <%s>\n",
+ host_address_to_string (gdbarch->in_indirect_branch_thunk));
+ fprintf_unfiltered (file,
"gdbarch_dump: in_solib_return_trampoline = <%s>\n",
host_address_to_string (gdbarch->in_solib_return_trampoline));
fprintf_unfiltered (file,
@@ -3353,6 +3359,23 @@ set_gdbarch_in_solib_return_trampoline (struct gdbarch *gdbarch,
gdbarch->in_solib_return_trampoline = in_solib_return_trampoline;
}
+bool
+gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->in_indirect_branch_thunk != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_in_indirect_branch_thunk called\n");
+ return gdbarch->in_indirect_branch_thunk (gdbarch, pc);
+}
+
+void
+set_gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch,
+ gdbarch_in_indirect_branch_thunk_ftype in_indirect_branch_thunk)
+{
+ gdbarch->in_indirect_branch_thunk = in_indirect_branch_thunk;
+}
+
int
gdbarch_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR addr)
{
@@ -741,6 +741,12 @@ typedef int (gdbarch_in_solib_return_trampoline_ftype) (struct gdbarch *gdbarch,
extern int gdbarch_in_solib_return_trampoline (struct gdbarch *gdbarch, CORE_ADDR pc, const char *name);
extern void set_gdbarch_in_solib_return_trampoline (struct gdbarch *gdbarch, gdbarch_in_solib_return_trampoline_ftype *in_solib_return_trampoline);
+/* Return true if PC lies inside an indirect branch thunk. */
+
+typedef bool (gdbarch_in_indirect_branch_thunk_ftype) (struct gdbarch *gdbarch, CORE_ADDR pc);
+extern bool gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc);
+extern void set_gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch, gdbarch_in_indirect_branch_thunk_ftype *in_indirect_branch_thunk);
+
/* A target might have problems with watchpoints as soon as the stack
frame of the current function has been destroyed. This mostly happens
as the first action in a function's epilogue. stack_frame_destroyed_p()
@@ -660,6 +660,9 @@ m;CORE_ADDR;skip_solib_resolver;CORE_ADDR pc;pc;;generic_skip_solib_resolver;;0
# Some systems also have trampoline code for returning from shared libs.
m;int;in_solib_return_trampoline;CORE_ADDR pc, const char *name;pc, name;;generic_in_solib_return_trampoline;;0
+# Return true if PC lies inside an indirect branch thunk.
+m;bool;in_indirect_branch_thunk;CORE_ADDR pc;pc;;default_in_indirect_branch_thunk;;0
+
# A target might have problems with watchpoints as soon as the stack
# frame of the current function has been destroyed. This mostly happens
# as the first action in a function's epilogue. stack_frame_destroyed_p()
@@ -47,6 +47,7 @@
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "x86-xstate.h"
+#include "x86-tdep.h"
#include "record.h"
#include "record-full.h"
@@ -4421,6 +4422,15 @@ i386_gnu_triplet_regexp (struct gdbarch *gdbarch)
+/* Implement the "in_indirect_branch_thunk" gdbarch function. */
+
+static bool
+i386_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ return x86_in_indirect_branch_thunk (pc, i386_register_names,
+ I386_EAX_REGNUM, I386_EIP_REGNUM);
+}
+
/* Generic ELF. */
void
@@ -4447,6 +4457,9 @@ i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
i386_stap_is_single_operand);
set_gdbarch_stap_parse_special_token (gdbarch,
i386_stap_parse_special_token);
+
+ set_gdbarch_in_indirect_branch_thunk (gdbarch,
+ i386_in_indirect_branch_thunk);
}
/* System V Release 4 (SVR4). */
@@ -6570,6 +6570,17 @@ process_event_stop_test (struct execution_control_state *ecs)
return;
}
+ /* Step through an indirect branch thunk. */
+ if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
+ && gdbarch_in_indirect_branch_thunk (gdbarch, stop_pc))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: stepped into indirect branch thunk\n");
+ keep_going (ecs);
+ return;
+ }
+
if (ecs->event_thread->control.step_range_end != 1
&& (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
|| ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
new file mode 100644
@@ -0,0 +1,42 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 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/>.
+
+*/
+
+static int
+inc (int x)
+{ /* inc.1 */
+ return x + 1; /* inc.2 */
+} /* inc.3 */
+
+static int
+thrice (int (*op)(int), int x)
+{ /* thrice.1 */
+ x = op (x); /* thrice.2 */
+ x = op (x); /* thrice.3 */
+ return op (x); /* thrice.4 */
+} /* thrice.5 */
+
+int
+main ()
+{
+ int x;
+
+ x = thrice (inc, 40);
+
+ return x;
+}
new file mode 100644
@@ -0,0 +1,61 @@
+# Copyright 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/>.
+
+standard_testfile
+
+set cflags "-mindirect-branch=thunk -mfunction-return=thunk"
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
+ [list debug "additional_flags=$cflags"]] } {
+ return -1
+}
+
+if { ![runto_main] } {
+ untested "failed to run to main"
+ return -1
+}
+
+proc stepi_until { current target test } {
+ global gdb_prompt
+
+ gdb_test_multiple "stepi" "$test: stepi" {
+ -re "$current.*$gdb_prompt $" {
+ send_gdb "stepi\n"
+ exp_continue
+ }
+ -re "$target.*$gdb_prompt $" {
+ pass "$test: $target reached"
+ }
+ -re "$gdb_prompt $" {
+ fail "$test: $target not reached"
+ }
+ timeout {
+ fail "$test: timeout"
+ }
+ }
+}
+
+# Normal stepping steps through all thunks.
+gdb_test "step" "thrice\.2.*" "step into thrice"
+gdb_test "next" "thrice\.3.*" "step through thunks and over inc"
+gdb_test "step" "inc\.2.*" "step through call thunk into inc"
+gdb_test "step" "inc\.3.*" "step inside inc"
+gdb_test "step" "thrice\.4.*" "step through return thunk back into thrice"
+
+# We can use instruction stepping to step into thunks.
+stepi_until "thrice" "indirect_thunk" "stepi into call thunk"
+stepi_until "indirect_thunk" "inc." "stepi out of call thunk into inc"
+stepi_until "inc" "return_thunk" "stepi into return thunk"
+stepi_until "return_thunk" "thrice" \
+ "stepi out of return thunk back into thrice"
new file mode 100644
@@ -0,0 +1,36 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 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/>.
+
+*/
+
+static int
+inc (int x)
+{ /* inc.1 */
+ return x + 1; /* inc.2 */
+} /* inc.3 */
+
+static int
+apply (int (*op)(int), int x)
+{ /* apply.1 */
+ return op (x); /* apply.2 */
+} /* apply.3 */
+
+int
+main ()
+{ /* main.1 */
+ return apply (inc, 41); /* main.2 */
+} /* main.3 */
new file mode 100644
@@ -0,0 +1,87 @@
+# Copyright 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/>.
+
+if { ![supports_reverse] } {
+ untested "target does not support record"
+ return -1
+}
+
+standard_testfile
+
+set cflags "-mindirect-branch=thunk -mfunction-return=thunk"
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
+ [list debug "additional_flags=$cflags"]] } {
+ return -1
+}
+
+if { ![runto_main] } {
+ untested "failed to run to main"
+ return -1
+}
+
+proc step_until { command current target test } {
+ global gdb_prompt
+
+ gdb_test_multiple "$command" "$test: $command" {
+ -re "$current.*$gdb_prompt $" {
+ send_gdb "$command\n"
+ exp_continue
+ }
+ -re "$target.*$gdb_prompt $" {
+ pass "$test: $target reached"
+ }
+ -re "$gdb_prompt $" {
+ fail "$test: $target not reached"
+ }
+ timeout {
+ fail "$test: timeout"
+ }
+ }
+}
+
+gdb_test_no_output "record"
+gdb_test "next" ".*" "record trace"
+
+# Normal stepping steps through all thunks.
+gdb_test "reverse-step" "apply\.3.*" "reverse-step into apply"
+gdb_test "reverse-step" "inc\.3.*" "reverse-step into inc"
+gdb_test "reverse-step" "inc\.2.*" "reverse-step inside inc"
+gdb_test "reverse-step" "apply\.2.*" \
+ "reverse-step through call thunk into apply"
+gdb_test "reverse-step" "main\.2.*" "reverse-step into main"
+gdb_test "step" "apply\.2.*" "step into apply"
+gdb_test "step" "inc\.2.*" "step through call thunk into inc"
+gdb_test "reverse-step" "apply\.2.*" \
+ "reverse-step through call thunk into apply"
+gdb_test "next" "apply\.3.*" "step through thunks and over inc"
+gdb_test "reverse-next" "apply\.2.*" \
+ "reverse-step through thunks and over inc"
+
+# We can use instruction stepping to step into thunks.
+step_until "stepi" "apply\.2" "indirect_thunk" "stepi into call thunk"
+step_until "stepi" "indirect_thunk" "inc" \
+ "stepi out of call thunk into inc"
+step_until "stepi" "inc" "return_thunk" "stepi into return thunk"
+step_until "stepi" "return_thunk" "apply" \
+ "stepi out of return thunk back into apply"
+
+step_until "reverse-stepi" "apply" "return_thunk" \
+ "reverse-stepi into return thunk"
+step_until "reverse-stepi" "return_thunk" "inc" \
+ "reverse-stepi out of return thunk into inc"
+step_until "reverse-stepi" "inc" "indirect_thunk" \
+ "reverse-stepi into call thunk"
+step_until "reverse-stepi" "indirect_thunk" "apply" \
+ "reverse-stepi out of call thunk into apply"
new file mode 100644
@@ -0,0 +1,75 @@
+/* Target-dependent code for X86-based targets.
+
+ Copyright (C) 2018 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 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/>. */
+
+#include "x86-tdep.h"
+
+
+/* Check whether NAME is included in NAMES[LO] (inclusive) to NAMES[HI]
+ (exclusive). */
+
+static bool
+x86_is_thunk_register_name (const char *name, const char **names, int lo,
+ int hi)
+{
+ int reg;
+ for (reg = lo; reg < hi; ++reg)
+ if (strcmp (name, names[reg]) == 0)
+ return true;
+
+ return false;
+}
+
+/* See x86-tdep.h. */
+
+bool
+x86_in_indirect_branch_thunk (CORE_ADDR pc, const char **register_names,
+ int lo, int hi)
+{
+ struct bound_minimal_symbol bmfun = lookup_minimal_symbol_by_pc (pc);
+ if (bmfun.minsym == nullptr)
+ return false;
+
+ const char *name = MSYMBOL_LINKAGE_NAME (bmfun.minsym);
+ if (name == nullptr)
+ return false;
+
+ /* Check the indirect return thunk first. */
+ if (strcmp (name, "__x86_return_thunk") == 0)
+ return true;
+
+ /* Then check a family of indirect call/jump thunks. */
+ static const char thunk[] = "__x86_indirect_thunk";
+ static const size_t length = sizeof (thunk) - 1;
+ if (strncmp (name, thunk, length) != 0)
+ return false;
+
+ /* If that's the complete name, we're in the memory thunk. */
+ name += length;
+ if (*name == 0)
+ return true;
+
+ /* Check for suffixes. */
+ if (*name++ != '_')
+ return false;
+
+ if (x86_is_thunk_register_name (name, register_names, lo, hi))
+ return true;
+
+ return false;
+}
new file mode 100644
@@ -0,0 +1,32 @@
+/* Target-dependent code for X86-based targets.
+
+ Copyright (C) 2018 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 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/>. */
+
+#ifndef X86_TDEP_H
+#define X86_TDEP_H
+
+#include "defs.h"
+
+/* Checks whether PC lies in an indirect branch thunk using registers
+ REGISTER_NAMES[LO] (inclusive) to REGISTER_NAMES[HI] (exclusive). */
+
+extern bool x86_in_indirect_branch_thunk (CORE_ADDR pc,
+ const char **register_names,
+ int lo, int hi);
+
+#endif /* x86-tdep.h */