Say:
<stopped at a breakpoint in thread 2>
(gdb) thread 3
(gdb) step
The above triggers the prepare_to_proceed/deferred_step_ptid process,
which switches back to thread 2, to step over its breakpoint before
getting back to thread 3 and "step" it.
If while stepping over the breakpoint in thread 2, a signal arrives,
and it is set to pass/nostop, we'll set a step-resume breakpoint at
the supposed signal-handler resume address, and call keep_going. The
problem is that we were supposedly stepping thread 3, and that
keep_going delivers a signal to thread 2, and due to scheduler-locking
off, resumes everything else, _including_ thread 3, the thread we want
stepping. This means that we lose control of thread 3 until the next
event, when we stop everything. The end result for the user, is that
GDB lost control of the "step".
Here's the current infrun debug output of the above, with the testcase
in the patch below:
infrun: clear_proceed_status_thread (Thread 0x2aaaab8f5700 (LWP 11663))
infrun: clear_proceed_status_thread (Thread 0x2aaaab6f4700 (LWP 11662))
infrun: clear_proceed_status_thread (Thread 0x2aaaab4f2b20 (LWP 11659))
infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
infrun: prepare_to_proceed (step=1), switched to [Thread 0x2aaaab6f4700 (LWP 11662)]
infrun: resume (step=1, signal=0), trap_expected=1, current thread [Thread 0x2aaaab6f4700 (LWP 11662)] at 0x40098f
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab6f4700 (LWP 11662)],
infrun: status->kind = stopped, signal = SIGUSR1
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40098f
infrun: random signal 30
Program received signal SIGUSR1, User defined signal 1.
infrun: signal arrived while stepping over breakpoint
infrun: inserting step-resume breakpoint at 0x40098f
infrun: resume (step=0, signal=30), trap_expected=0, current thread [Thread 0x2aaaab6f4700 (LWP 11662)] at 0x40098f
^^^ this is a wildcard resume.
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab6f4700 (LWP 11662)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40098f
infrun: BPSTAT_WHAT_STEP_RESUME
infrun: resume (step=1, signal=0), trap_expected=1, current thread [Thread 0x2aaaab6f4700 (LWP 11662)] at 0x40098f
^^^ step-resume hit, meaning the handler returned, so we go back to stepping thread 3.
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab6f4700 (LWP 11662)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40088b
infrun: switching back to stepped thread
infrun: Switching context from Thread 0x2aaaab6f4700 (LWP 11662) to Thread 0x2aaaab8f5700 (LWP 11663)
infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x2aaaab8f5700 (LWP 11663)] at 0x400938
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab8f5700 (LWP 11663)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40093a
infrun: keep going
infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x2aaaab8f5700 (LWP 11663)] at 0x40093a
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab8f5700 (LWP 11663)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40091e
infrun: stepped to a different line
infrun: stop_stepping
[Switching to Thread 0x2aaaab8f5700 (LWP 11663)]
69 (*myp) ++; /* set breakpoint child_two here */
^^^ we stopped at the wrong line. We still stepped a bit because the
test is running in a loop, and when we got back to stepping thread 3,
it happened to be in the stepping range. (The loop increments a
counter, and the test makes sure it increments exactly once. Without
the fix, the counter increments a bunch, since the user-stepped thread
runs free without GDB noticing.)
The fix is to switch to the stepping thread before continuing for the
step-resume breakpoint.
gdb/
2014-02-07 Pedro Alves <palves@redhat.com>
* infrun.c (handle_signal_stop) <signal arrives while stepping
over a breakpoint>: Switch back to the stepping thread.
gdb/testsuite/
2014-02-07 Pedro Alves <pedro@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdb.threads/step-after-sr-lock.c: New file.
* gdb.threads/step-after-sr-lock.exp: New file.
This patch handles another aspect of the ELFv2 ABI, which unfortunately
requires common code changes.
In ELFv2, functions may provide both a global and a local entry point.
The global entry point (where the function symbol points to) is intended
to be used for function-pointer or cross-module (PLT) calls, and requires
r12 to be set up to the entry point address itself. The local entry
point (which is found at a fixed offset after the global entry point,
as defined by bits in the symbol table entries' st_other field), instead
expects r2 to be set up to the current TOC.
Now, when setting a breakpoint on a function by name, you really want
that breakpoint to trigger either way, no matter whether the function
is called via its local or global entry point. Since the global entry
point will always fall through into the local entry point, the way to
achieve that is to simply set the breakpoint at the local entry point.
One way to do that would be to have prologue parsing skip the code
sequence that makes up the global entry point. Unfortunately, this
does not work reliably, since -for optimized code- GDB these days
will not actuall invoke the prologue parsing code but instead just
set the breakpoint at the symbol address and rely on DWARF being
correct at any point throughout the function ...
Unfortunately, I don't really see any way to express the notion of
local entry points with the current set of gdbarch callbacks.
Thus this patch adds a new callback, skip_entrypoint, that is
somewhat analogous to skip_prologue, but is called every time
GDB needs to determine a function start address, even in those
cases where GDB decides to not call skip_prologue.
As a side effect, the skip_entrypoint implementation on ppc64
does not need to perform any instruction parsing; it can simply
rely on the local entry point flags in the symbol table entry.
With this implemented, two test cases would still fail to set
the breakpoint correctly, but that's because they use the construct:
gdb_test "break *hello"
Now, using "*hello" explicitly instructs GDB to set the breakpoint
at the numerical value of "hello" treated as function pointer, so
it will by definition only hit the global entry point.
I think this behaviour is unavoidable, but acceptable -- most people
do not use this construct, and if they do, they get what they
asked for ...
In one of those two test cases, use of this construct is really
not appropriate. I think this was added way back when as a means
to work around prologue skipping problems on some platforms. These
days that shouldn't really be necessary any more ...
For the other (step-bt), we really want to make sure backtracing
works on the very first instruction of the routine. To enable that
test also on powerpc64le-linux, we can modify the code to call the
test function via function pointer (which makes it use the global
entry point in the ELFv2 ABI).
gdb/ChangeLog:
* gdbarch.sh (skip_entrypoint): New callback.
* gdbarch.c, gdbarch.h: Regenerate.
* symtab.c (skip_prologue_sal): Call gdbarch_skip_entrypoint.
* infrun.c (fill_in_stop_func): Likewise.
* ppc-linux-tdep.c: Include "elf/ppc64.h".
(ppc_elfv2_elf_make_msymbol_special): New function.
(ppc_elfv2_skip_entrypoint): Likewise.
(ppc_linux_init_abi): Install them for ELFv2.
gdb/testsuite/ChangeLog:
* gdb.base/sigbpt.exp: Do not use "*" when setting breakpoint
on a function.
* gdb.base/step-bt.c: Call hello via function pointer to make
sure its first instruction is executed on powerpc64le-linux.
RECORD_IS_USED and record_full_open look at current_target.to_stratum
to determine whether a record target is in use. This is wrong because
arch_stratum is greater than record_stratum, so if an arch_stratum
target is pushed, RECORD_IS_USED and record_full_open will miss it.
To fix this, we can use the existing find_record_target instead, which
looks up for a record stratum target across the target stack. Since
that means exporting find_record_target in record.h, RECORD_IS_USED
ends up redundant, so the patch eliminates it.
That exercise then reveals other issues:
- adjust_pc_after_break is gating record_full_... calls based on
RECORD_IS_USED. But, record_full_ calls shouldn't be made when
recording with the record-btrace target. So this adds a new
record_full_is_used predicate to be used in that spot.
- record_full_open says "Process record target already running", even
if the recording target is record-btrace ("process record" is the
original complete name of the record-full target). record_btrace_open
only says "The process is already being recorded." and does not
suggest "record stop", like record-full does. The patch factors out
and merges that error to a new record_preopen function that all record
targets call in their open routine.
Tested on x86_64 Fedora 17.
gdb/
2014-01-14 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* infrun.c (use_displaced_stepping): Use find_record_target
instead of RECORD_IS_USED.
(adjust_pc_after_break): Use record_full_is_used instead of
RECORD_IS_USED.
* record-btrace.c (record_btrace_open): Call record_preopen
instead of checking RECORD_IS_USED.
* record-full.c (record_full_shortname)
(record_full_core_shortname): New globals.
(record_full_is_used): New function.
(find_full_open): Call record_preopen instead of checking
RECORD_IS_USED.
(init_record_full_ops): Set the target's shortname to
record_full_shortname.
(init_record_full_core_ops): Set the target's shortname to
record_full_core_shortname.
* record-full.h (record_full_is_used): Declare.
* record.c (find_record_target): Make extern.
(record_preopen): New function.
* record.h (RECORD_IS_USED): Delete macro.
(find_record_target, record_preopen): Declare functions.
This removes gdb_string.h. This patch is purely mechanical. I
created it by running the two commands:
git rm common/gdb_string.h
perl -pi -e's/"gdb_string.h"/<string.h>/;' *.[chyl] */*.[chyl]
2013-11-18 Tom Tromey <tromey@redhat.com>
* common/gdb_string.h: Remove.
* aarch64-tdep.c: Use string.h, not gdb_string.h.
* ada-exp.y: Use string.h, not gdb_string.h.
* ada-lang.c: Use string.h, not gdb_string.h.
* ada-lex.l: Use string.h, not gdb_string.h.
* ada-typeprint.c: Use string.h, not gdb_string.h.
* ada-valprint.c: Use string.h, not gdb_string.h.
* aix-thread.c: Use string.h, not gdb_string.h.
* alpha-linux-tdep.c: Use string.h, not gdb_string.h.
* alpha-mdebug-tdep.c: Use string.h, not gdb_string.h.
* alpha-nat.c: Use string.h, not gdb_string.h.
* alpha-osf1-tdep.c: Use string.h, not gdb_string.h.
* alpha-tdep.c: Use string.h, not gdb_string.h.
* alphanbsd-tdep.c: Use string.h, not gdb_string.h.
* amd64-dicos-tdep.c: Use string.h, not gdb_string.h.
* amd64-linux-nat.c: Use string.h, not gdb_string.h.
* amd64-linux-tdep.c: Use string.h, not gdb_string.h.
* amd64-nat.c: Use string.h, not gdb_string.h.
* amd64-sol2-tdep.c: Use string.h, not gdb_string.h.
* amd64fbsd-tdep.c: Use string.h, not gdb_string.h.
* amd64obsd-tdep.c: Use string.h, not gdb_string.h.
* arch-utils.c: Use string.h, not gdb_string.h.
* arm-linux-nat.c: Use string.h, not gdb_string.h.
* arm-linux-tdep.c: Use string.h, not gdb_string.h.
* arm-tdep.c: Use string.h, not gdb_string.h.
* arm-wince-tdep.c: Use string.h, not gdb_string.h.
* armbsd-tdep.c: Use string.h, not gdb_string.h.
* armnbsd-nat.c: Use string.h, not gdb_string.h.
* armnbsd-tdep.c: Use string.h, not gdb_string.h.
* armobsd-tdep.c: Use string.h, not gdb_string.h.
* avr-tdep.c: Use string.h, not gdb_string.h.
* ax-gdb.c: Use string.h, not gdb_string.h.
* ax-general.c: Use string.h, not gdb_string.h.
* bcache.c: Use string.h, not gdb_string.h.
* bfin-tdep.c: Use string.h, not gdb_string.h.
* breakpoint.c: Use string.h, not gdb_string.h.
* build-id.c: Use string.h, not gdb_string.h.
* buildsym.c: Use string.h, not gdb_string.h.
* c-exp.y: Use string.h, not gdb_string.h.
* c-lang.c: Use string.h, not gdb_string.h.
* c-typeprint.c: Use string.h, not gdb_string.h.
* c-valprint.c: Use string.h, not gdb_string.h.
* charset.c: Use string.h, not gdb_string.h.
* cli-out.c: Use string.h, not gdb_string.h.
* cli/cli-cmds.c: Use string.h, not gdb_string.h.
* cli/cli-decode.c: Use string.h, not gdb_string.h.
* cli/cli-dump.c: Use string.h, not gdb_string.h.
* cli/cli-interp.c: Use string.h, not gdb_string.h.
* cli/cli-logging.c: Use string.h, not gdb_string.h.
* cli/cli-script.c: Use string.h, not gdb_string.h.
* cli/cli-setshow.c: Use string.h, not gdb_string.h.
* cli/cli-utils.c: Use string.h, not gdb_string.h.
* coffread.c: Use string.h, not gdb_string.h.
* common/common-utils.c: Use string.h, not gdb_string.h.
* common/filestuff.c: Use string.h, not gdb_string.h.
* common/linux-procfs.c: Use string.h, not gdb_string.h.
* common/linux-ptrace.c: Use string.h, not gdb_string.h.
* common/signals.c: Use string.h, not gdb_string.h.
* common/vec.h: Use string.h, not gdb_string.h.
* core-regset.c: Use string.h, not gdb_string.h.
* corefile.c: Use string.h, not gdb_string.h.
* corelow.c: Use string.h, not gdb_string.h.
* cp-abi.c: Use string.h, not gdb_string.h.
* cp-support.c: Use string.h, not gdb_string.h.
* cp-valprint.c: Use string.h, not gdb_string.h.
* cris-tdep.c: Use string.h, not gdb_string.h.
* d-lang.c: Use string.h, not gdb_string.h.
* dbxread.c: Use string.h, not gdb_string.h.
* dcache.c: Use string.h, not gdb_string.h.
* demangle.c: Use string.h, not gdb_string.h.
* dicos-tdep.c: Use string.h, not gdb_string.h.
* disasm.c: Use string.h, not gdb_string.h.
* doublest.c: Use string.h, not gdb_string.h.
* dsrec.c: Use string.h, not gdb_string.h.
* dummy-frame.c: Use string.h, not gdb_string.h.
* dwarf2-frame.c: Use string.h, not gdb_string.h.
* dwarf2loc.c: Use string.h, not gdb_string.h.
* dwarf2read.c: Use string.h, not gdb_string.h.
* elfread.c: Use string.h, not gdb_string.h.
* environ.c: Use string.h, not gdb_string.h.
* eval.c: Use string.h, not gdb_string.h.
* event-loop.c: Use string.h, not gdb_string.h.
* exceptions.c: Use string.h, not gdb_string.h.
* exec.c: Use string.h, not gdb_string.h.
* expprint.c: Use string.h, not gdb_string.h.
* f-exp.y: Use string.h, not gdb_string.h.
* f-lang.c: Use string.h, not gdb_string.h.
* f-typeprint.c: Use string.h, not gdb_string.h.
* f-valprint.c: Use string.h, not gdb_string.h.
* fbsd-nat.c: Use string.h, not gdb_string.h.
* findcmd.c: Use string.h, not gdb_string.h.
* findvar.c: Use string.h, not gdb_string.h.
* fork-child.c: Use string.h, not gdb_string.h.
* frame.c: Use string.h, not gdb_string.h.
* frv-linux-tdep.c: Use string.h, not gdb_string.h.
* frv-tdep.c: Use string.h, not gdb_string.h.
* gdb.c: Use string.h, not gdb_string.h.
* gdb_bfd.c: Use string.h, not gdb_string.h.
* gdbarch.c: Use string.h, not gdb_string.h.
* gdbtypes.c: Use string.h, not gdb_string.h.
* gnu-nat.c: Use string.h, not gdb_string.h.
* gnu-v2-abi.c: Use string.h, not gdb_string.h.
* gnu-v3-abi.c: Use string.h, not gdb_string.h.
* go-exp.y: Use string.h, not gdb_string.h.
* go-lang.c: Use string.h, not gdb_string.h.
* go32-nat.c: Use string.h, not gdb_string.h.
* hppa-hpux-tdep.c: Use string.h, not gdb_string.h.
* hppa-linux-nat.c: Use string.h, not gdb_string.h.
* hppanbsd-tdep.c: Use string.h, not gdb_string.h.
* hppaobsd-tdep.c: Use string.h, not gdb_string.h.
* i386-cygwin-tdep.c: Use string.h, not gdb_string.h.
* i386-dicos-tdep.c: Use string.h, not gdb_string.h.
* i386-linux-nat.c: Use string.h, not gdb_string.h.
* i386-linux-tdep.c: Use string.h, not gdb_string.h.
* i386-nto-tdep.c: Use string.h, not gdb_string.h.
* i386-sol2-tdep.c: Use string.h, not gdb_string.h.
* i386-tdep.c: Use string.h, not gdb_string.h.
* i386bsd-tdep.c: Use string.h, not gdb_string.h.
* i386gnu-nat.c: Use string.h, not gdb_string.h.
* i386nbsd-tdep.c: Use string.h, not gdb_string.h.
* i386obsd-tdep.c: Use string.h, not gdb_string.h.
* i387-tdep.c: Use string.h, not gdb_string.h.
* ia64-libunwind-tdep.c: Use string.h, not gdb_string.h.
* ia64-linux-nat.c: Use string.h, not gdb_string.h.
* inf-child.c: Use string.h, not gdb_string.h.
* inf-ptrace.c: Use string.h, not gdb_string.h.
* inf-ttrace.c: Use string.h, not gdb_string.h.
* infcall.c: Use string.h, not gdb_string.h.
* infcmd.c: Use string.h, not gdb_string.h.
* inflow.c: Use string.h, not gdb_string.h.
* infrun.c: Use string.h, not gdb_string.h.
* interps.c: Use string.h, not gdb_string.h.
* iq2000-tdep.c: Use string.h, not gdb_string.h.
* irix5-nat.c: Use string.h, not gdb_string.h.
* jv-exp.y: Use string.h, not gdb_string.h.
* jv-lang.c: Use string.h, not gdb_string.h.
* jv-typeprint.c: Use string.h, not gdb_string.h.
* jv-valprint.c: Use string.h, not gdb_string.h.
* language.c: Use string.h, not gdb_string.h.
* linux-fork.c: Use string.h, not gdb_string.h.
* linux-nat.c: Use string.h, not gdb_string.h.
* lm32-tdep.c: Use string.h, not gdb_string.h.
* m2-exp.y: Use string.h, not gdb_string.h.
* m2-typeprint.c: Use string.h, not gdb_string.h.
* m32c-tdep.c: Use string.h, not gdb_string.h.
* m32r-linux-nat.c: Use string.h, not gdb_string.h.
* m32r-linux-tdep.c: Use string.h, not gdb_string.h.
* m32r-rom.c: Use string.h, not gdb_string.h.
* m32r-tdep.c: Use string.h, not gdb_string.h.
* m68hc11-tdep.c: Use string.h, not gdb_string.h.
* m68k-tdep.c: Use string.h, not gdb_string.h.
* m68kbsd-tdep.c: Use string.h, not gdb_string.h.
* m68klinux-nat.c: Use string.h, not gdb_string.h.
* m68klinux-tdep.c: Use string.h, not gdb_string.h.
* m88k-tdep.c: Use string.h, not gdb_string.h.
* macrocmd.c: Use string.h, not gdb_string.h.
* main.c: Use string.h, not gdb_string.h.
* mdebugread.c: Use string.h, not gdb_string.h.
* mem-break.c: Use string.h, not gdb_string.h.
* memattr.c: Use string.h, not gdb_string.h.
* memory-map.c: Use string.h, not gdb_string.h.
* mep-tdep.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-break.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-disas.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-env.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-stack.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-var.c: Use string.h, not gdb_string.h.
* mi/mi-cmds.c: Use string.h, not gdb_string.h.
* mi/mi-console.c: Use string.h, not gdb_string.h.
* mi/mi-getopt.c: Use string.h, not gdb_string.h.
* mi/mi-interp.c: Use string.h, not gdb_string.h.
* mi/mi-main.c: Use string.h, not gdb_string.h.
* mi/mi-parse.c: Use string.h, not gdb_string.h.
* microblaze-rom.c: Use string.h, not gdb_string.h.
* microblaze-tdep.c: Use string.h, not gdb_string.h.
* mingw-hdep.c: Use string.h, not gdb_string.h.
* minidebug.c: Use string.h, not gdb_string.h.
* minsyms.c: Use string.h, not gdb_string.h.
* mips-irix-tdep.c: Use string.h, not gdb_string.h.
* mips-linux-tdep.c: Use string.h, not gdb_string.h.
* mips-tdep.c: Use string.h, not gdb_string.h.
* mips64obsd-tdep.c: Use string.h, not gdb_string.h.
* mipsnbsd-tdep.c: Use string.h, not gdb_string.h.
* mipsread.c: Use string.h, not gdb_string.h.
* mn10300-linux-tdep.c: Use string.h, not gdb_string.h.
* mn10300-tdep.c: Use string.h, not gdb_string.h.
* monitor.c: Use string.h, not gdb_string.h.
* moxie-tdep.c: Use string.h, not gdb_string.h.
* mt-tdep.c: Use string.h, not gdb_string.h.
* nbsd-tdep.c: Use string.h, not gdb_string.h.
* nios2-linux-tdep.c: Use string.h, not gdb_string.h.
* nto-procfs.c: Use string.h, not gdb_string.h.
* nto-tdep.c: Use string.h, not gdb_string.h.
* objc-lang.c: Use string.h, not gdb_string.h.
* objfiles.c: Use string.h, not gdb_string.h.
* opencl-lang.c: Use string.h, not gdb_string.h.
* osabi.c: Use string.h, not gdb_string.h.
* osdata.c: Use string.h, not gdb_string.h.
* p-exp.y: Use string.h, not gdb_string.h.
* p-lang.c: Use string.h, not gdb_string.h.
* p-typeprint.c: Use string.h, not gdb_string.h.
* parse.c: Use string.h, not gdb_string.h.
* posix-hdep.c: Use string.h, not gdb_string.h.
* ppc-linux-nat.c: Use string.h, not gdb_string.h.
* ppc-sysv-tdep.c: Use string.h, not gdb_string.h.
* ppcfbsd-tdep.c: Use string.h, not gdb_string.h.
* ppcnbsd-tdep.c: Use string.h, not gdb_string.h.
* ppcobsd-tdep.c: Use string.h, not gdb_string.h.
* printcmd.c: Use string.h, not gdb_string.h.
* procfs.c: Use string.h, not gdb_string.h.
* prologue-value.c: Use string.h, not gdb_string.h.
* python/py-auto-load.c: Use string.h, not gdb_string.h.
* python/py-gdb-readline.c: Use string.h, not gdb_string.h.
* ravenscar-thread.c: Use string.h, not gdb_string.h.
* regcache.c: Use string.h, not gdb_string.h.
* registry.c: Use string.h, not gdb_string.h.
* remote-fileio.c: Use string.h, not gdb_string.h.
* remote-m32r-sdi.c: Use string.h, not gdb_string.h.
* remote-mips.c: Use string.h, not gdb_string.h.
* remote-sim.c: Use string.h, not gdb_string.h.
* remote.c: Use string.h, not gdb_string.h.
* reverse.c: Use string.h, not gdb_string.h.
* rs6000-aix-tdep.c: Use string.h, not gdb_string.h.
* ser-base.c: Use string.h, not gdb_string.h.
* ser-go32.c: Use string.h, not gdb_string.h.
* ser-mingw.c: Use string.h, not gdb_string.h.
* ser-pipe.c: Use string.h, not gdb_string.h.
* ser-tcp.c: Use string.h, not gdb_string.h.
* ser-unix.c: Use string.h, not gdb_string.h.
* serial.c: Use string.h, not gdb_string.h.
* sh-tdep.c: Use string.h, not gdb_string.h.
* sh64-tdep.c: Use string.h, not gdb_string.h.
* shnbsd-tdep.c: Use string.h, not gdb_string.h.
* skip.c: Use string.h, not gdb_string.h.
* sol-thread.c: Use string.h, not gdb_string.h.
* solib-dsbt.c: Use string.h, not gdb_string.h.
* solib-frv.c: Use string.h, not gdb_string.h.
* solib-osf.c: Use string.h, not gdb_string.h.
* solib-spu.c: Use string.h, not gdb_string.h.
* solib-target.c: Use string.h, not gdb_string.h.
* solib.c: Use string.h, not gdb_string.h.
* somread.c: Use string.h, not gdb_string.h.
* source.c: Use string.h, not gdb_string.h.
* sparc-nat.c: Use string.h, not gdb_string.h.
* sparc-sol2-tdep.c: Use string.h, not gdb_string.h.
* sparc-tdep.c: Use string.h, not gdb_string.h.
* sparc64-tdep.c: Use string.h, not gdb_string.h.
* sparc64fbsd-tdep.c: Use string.h, not gdb_string.h.
* sparc64nbsd-tdep.c: Use string.h, not gdb_string.h.
* sparcnbsd-tdep.c: Use string.h, not gdb_string.h.
* spu-linux-nat.c: Use string.h, not gdb_string.h.
* spu-multiarch.c: Use string.h, not gdb_string.h.
* spu-tdep.c: Use string.h, not gdb_string.h.
* stabsread.c: Use string.h, not gdb_string.h.
* stack.c: Use string.h, not gdb_string.h.
* std-regs.c: Use string.h, not gdb_string.h.
* symfile.c: Use string.h, not gdb_string.h.
* symmisc.c: Use string.h, not gdb_string.h.
* symtab.c: Use string.h, not gdb_string.h.
* target.c: Use string.h, not gdb_string.h.
* thread.c: Use string.h, not gdb_string.h.
* tilegx-linux-nat.c: Use string.h, not gdb_string.h.
* tilegx-tdep.c: Use string.h, not gdb_string.h.
* top.c: Use string.h, not gdb_string.h.
* tracepoint.c: Use string.h, not gdb_string.h.
* tui/tui-command.c: Use string.h, not gdb_string.h.
* tui/tui-data.c: Use string.h, not gdb_string.h.
* tui/tui-disasm.c: Use string.h, not gdb_string.h.
* tui/tui-file.c: Use string.h, not gdb_string.h.
* tui/tui-layout.c: Use string.h, not gdb_string.h.
* tui/tui-out.c: Use string.h, not gdb_string.h.
* tui/tui-regs.c: Use string.h, not gdb_string.h.
* tui/tui-source.c: Use string.h, not gdb_string.h.
* tui/tui-stack.c: Use string.h, not gdb_string.h.
* tui/tui-win.c: Use string.h, not gdb_string.h.
* tui/tui-windata.c: Use string.h, not gdb_string.h.
* tui/tui-winsource.c: Use string.h, not gdb_string.h.
* typeprint.c: Use string.h, not gdb_string.h.
* ui-file.c: Use string.h, not gdb_string.h.
* ui-out.c: Use string.h, not gdb_string.h.
* user-regs.c: Use string.h, not gdb_string.h.
* utils.c: Use string.h, not gdb_string.h.
* v850-tdep.c: Use string.h, not gdb_string.h.
* valarith.c: Use string.h, not gdb_string.h.
* valops.c: Use string.h, not gdb_string.h.
* valprint.c: Use string.h, not gdb_string.h.
* value.c: Use string.h, not gdb_string.h.
* varobj.c: Use string.h, not gdb_string.h.
* vax-tdep.c: Use string.h, not gdb_string.h.
* vaxnbsd-tdep.c: Use string.h, not gdb_string.h.
* vaxobsd-tdep.c: Use string.h, not gdb_string.h.
* windows-nat.c: Use string.h, not gdb_string.h.
* xcoffread.c: Use string.h, not gdb_string.h.
* xml-support.c: Use string.h, not gdb_string.h.
* xstormy16-tdep.c: Use string.h, not gdb_string.h.
* xtensa-linux-nat.c: Use string.h, not gdb_string.h.
Before all this stop_soon handling, we have code that can end in
keep_going. Particularly, the thread_hop_needed code looked
suspicious considering breakpoint always-inserted mode, though on
closer inspection, it'd take connecting to multiple remote targets
that shared the same address space to trigger that.
Still, I think it's clearer if all this remote connection setup /
attach code is placed early, before any keep_going path could be
reached.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (handle_signal_stop): Move STOP_QUIETLY,
STOP_QUIETLY_REMOTE and 'stop_after_trap' handling earlier.
After the previous patches, we only ever reach the code after the
initial 'switch (ecs->ws.kind)' switch for TARGET_WAITKIND_STOPPED.
We can now factor out all that to its own function.
Unfortunately, stepped_after_stopped_by_watchpoint needed to move to
the ecs. I think that indicates a state machine bug -- no event other
than TARGET_WAITKIND_STOPPED indicates a single-step actually
finished. TARGET_WAITKIND_SYSCALL_XXX, TARGET_WAITKIND_FORK, etc. are
all events that are triggered from the kernel, _within_ a syscall,
IOW, from userspace's perspective, halfway through an instruction
being executed. This might actually matter for the syscall events, as
syscalls can change memory (and thus trigger watchpoints).
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (struct execution_control_state)
<stepped_after_stopped_by_watchpoint>: New field.
(get_inferior_stop_soon): New function.
(handle_inferior_event): 'stepped_after_stopped_by_watchpoint' was
moved to struct execution_control_state -- adjust. Use
get_inferior_stop_soon. Split TARGET_WAITKIND_STOPPED handling to
new function.
(handle_signal_stop): New function, factored out from
handle_inferior_event.
After the previous patch, there's actually no breakpoint type that
returns BPSTAT_SIGNAL_HIDE, so we can go back to having
bpstat_explains_signal return a boolean. The signal hiding actually
disappears.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* break-catch-sig.c (signal_catchpoint_explains_signal): Adjust to
return a boolean.
* breakpoint.c (bpstat_explains_signal): Adjust to return a
boolean.
(explains_signal_watchpoint, base_breakpoint_explains_signal):
Adjust to return a boolean.
* breakpoint.h (enum bpstat_signal_value): Delete.
(struct breakpoint_ops) <explains_signal>: New returns a boolean.
(bpstat_explains_signal): Likewise.
* infrun.c (handle_inferior_event) <random signal checks>:
bpstat_explains_signal now returns a boolean - adjust. No longer
consider hiding signals.
Looking at the current random signal checks:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
random_signal
= !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
GDB_SIGNAL_TRAP)
!= BPSTAT_SIGNAL_NO)
|| stopped_by_watchpoint
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
else
{
enum bpstat_signal_value sval;
sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
ecs->event_thread->suspend.stop_signal);
random_signal = (sval == BPSTAT_SIGNAL_NO);
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
}
We can observe:
- the stepping checks bit:
...
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
...
is just like currently_stepping:
static int
currently_stepping (struct thread_info *tp)
{
return ((tp->control.step_range_end
&& tp->control.step_resume_breakpoint == NULL)
|| tp->control.trap_expected
|| bpstat_should_step ());
}
except it misses the bpstat_should_step check (***).
It's not really necessary to check bpstat_should_step in the
random signal tests, because software watchpoints always end up in
the bpstat list anyway, which means bpstat_explains_signal with
GDB_SIGNAL_TRAP always returns at least BPSSTAT_SIGNAL_HIDE, but I
think the code is clearer if we reuse currently_stepping.
*** - bpstat_should_step checks to see if there's any software
watchpoint in the breakpoint list, because we need to force the
target to single-step all the way, to evaluate the watchpoint's
value at each step.
- we never hide GDB_SIGNAL_TRAP, even if the bpstat returns
BPSTAT_SIGNAL_HIDE, which is actually the default for all
breakpoints. If we make the default be BPSTAT_SIGNAL_PASS, then
we can merge the two bpstat_explains_signal paths.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* breakpoint.c (bpstat_explains_signal) <Moribund locations>:
Return BPSTAT_SIGNAL_PASS instead of BPSTAT_SIGNAL_HIDE.
(explains_signal_watchpoint): Return BPSTAT_SIGNAL_PASS instead of
BPSTAT_SIGNAL_HIDE.
(base_breakpoint_explains_signal): Return BPSTAT_SIGNAL_PASS
instead of BPSTAT_SIGNAL_HIDE.
* infrun.c (handle_inferior_event): Rework random signal checks.
This goes a step forward in making only TARGET_WAITKIND_STOPPED talk
about signals.
There's no reason for the "catchpoint" TARGET_WAITKIND_XXXs to consult
bpstat about signals -- unlike breakpoints, all these events are
continuable, so we don't need to do a remove-break/step/reinsert-break
-like dance. That means we don't actually need to run them through
process_event_stop_test (for the bpstat_what checks), and can just use
bpstat_causes_stop instead. Note we were already using it in the
TARGET_WAITKIND_(V)FORKED cases.
Then, these "catchpoint" waitkinds don't need to set
ecs->random_signal for anything, because they check it immediately
afterwards (and the value they set is never used again).
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (struct execution_control_state): Remove
'random_signal' field.
(handle_syscall_event): Use bpstat_causes_stop instead of
bpstat_explains_signal. Don't set ecs->random_signal.
(handle_inferior_event): New 'random_signal' local.
<TARGET_WAITKIND_FORKED, TARGET_WAITKIND_VFORKED,
TARGET_WAITKIND_EXECD>: Use bpstat_causes_stop instead of
bpstat_explains_signal. Don't set ecs->random_signal.
<TARGET_WAITKIND_STOPPED>: Adjust to use local instead of
ecs->random_signal.
This comment applies to the whole handle_inferior_event flow, top to
bottom. Best move it to the function's intro.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event): Move comment from the
function's body to the function's description, adjusted.
Of all the TARGET_WAITKIND_XXXs event kinds other than
TARGET_WAITKIND_STOPPED, TARGET_WAITKIND_LOADED is the only kind that
doesn't end in a return, instead falling through to all the
signal/breakpoint/stepping handling code. But it only falls through
in the STOP_QUIETLY_NO_SIGSTOP and STOP_QUIETLY_REMOTE cases, which
means the
/* This is originated from start_remote(), start_inferior() and
shared libraries hook functions. */
if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
stop_stepping (ecs);
return;
}
bit is eventually reached. All tests before that is reached will
always fail. It's simpler to inline the stop_soon checks close to the
TARGET_WAITKIND_LOADED code, which allows removing the fall through.
Tested on x86_64 Fedora 17, but that doesn't exercise this
TARGET_WAITKIND_LOADED.
Also ran gdb.base/solib-disc.exp on Cygwin/gdbserver, which exercises
reconnection while the inferior is stopped at an solib event, but then
again, gdbserver always replies a regular trap on initial connection,
instead of the last event the program had seen:
Sending packet: $?#3f...Packet received: T0505:4ca72800;04:f8a62800;08:62fcc877;thread:d28;
Sending packet: $Hc-1#09...Packet received: E01
Sending packet: $qAttached#8f...Packet received: 0
Packet qAttached (query-attached) is supported
infrun: clear_proceed_status_thread (Thread 3368)
Sending packet: $qOffsets#4b...Packet received:
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 42000 [Thread 3368],
infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x77c8fc62
infrun: quietly stopped
infrun: stop_stepping
So the only way to exercise this would be to hack gdbserver. I didn't
go that far though. I'm reasonably confident this is correct.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event) <TARGET_WAITKIND_LOADED>:
Handle STOP_QUIETLY_NO_SIGSTOP and STOP_QUIETLY_REMOTE here.
Assert we never fall through out of the TARGET_WAITKIND_LOADED
case.
IMO, it doesn't make sense to map random syscall, fork, etc. events to
GDB_SIGNAL_TRAP, and possible have the debuggee see that trap. This
just seems conceptually wrong to me - these aren't real signals a
debuggee would ever see. In fact, when stopped for those events, on
Linux, the debuggee isn't in a signal-stop -- there's no way to
resume-and-deliver-signal at that point, for example. E.g., when
stopped at a fork event:
(gdb) catch fork
Catchpoint 2 (fork)
(gdb) c
Continuing.
Catchpoint 2 (forked process 4570), 0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb) set debug infrun 1
(gdb) signal SIGTRAP
Continuing with signal SIGTRAP.
infrun: clear_proceed_status_thread (process 4566)
infrun: proceed (addr=0xffffffffffffffff, signal=5, step=0)
infrun: resume (step=0, signal=5), trap_expected=0, current thread [process 4566] at 0x323d4ba7c4
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 4566 [process 4566],
infrun: status->kind = exited, status = 0
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_EXITED
[Inferior 1 (process 4566) exited normally]
infrun: stop_stepping
(gdb)
Note the signal went nowhere. It was swallowed.
Resuming with a SIGTRAP from a syscall event does queue the signal,
but doesn't deliver it immediately, like "signal SIGTRAP" from a real
signal would. It's still an artificial SIGTRAP:
(gdb) catch syscall
Catchpoint 2 (any syscall)
(gdb) c
Continuing.
Catchpoint 2 (call to syscall clone), 0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb) set debug infrun 1
(gdb) signal SIGTRAP
Continuing with signal SIGTRAP.
infrun: clear_proceed_status_thread (process 4622)
infrun: proceed (addr=0xffffffffffffffff, signal=5, step=0)
infrun: resume (step=0, signal=5), trap_expected=0, current thread [process 4622] at 0x323d4ba7c4
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 4622 [process 4622],
infrun: status->kind = exited syscall
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_SYSCALL_RETURN
infrun: syscall number = '56'
infrun: BPSTAT_WHAT_STOP_NOISY
infrun: stop_stepping
Catchpoint 2 (returned from syscall clone), 0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb) c
Continuing.
infrun: clear_proceed_status_thread (process 4622)
infrun: proceed (addr=0xffffffffffffffff, signal=144, step=0)
infrun: resume (step=0, signal=0), trap_expected=0, current thread [process 4622] at 0x323d4ba7c4
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 4622 [process 4622],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4ba7c4
infrun: random signal 5
Program received signal SIGTRAP, Trace/breakpoint trap.
infrun: stop_stepping
0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb)
In all the above, I used 'signal SIGTRAP' to emulate 'handle SIGTRAP
pass'. As described in "keep_going", 'handle SIGTRAP pass' does have
its place:
/* Do not deliver GDB_SIGNAL_TRAP (except when the user
explicitly specifies that such a signal should be delivered
to the target program). Typically, that would occur when a
user is debugging a target monitor on a simulator: the target
monitor sets a breakpoint; the simulator encounters this
breakpoint and halts the simulation handing control to GDB;
GDB, noting that the stop address doesn't map to any known
breakpoint, returns control back to the simulator; the
simulator then delivers the hardware equivalent of a
GDB_SIGNAL_TRAP to the program being debugged. */
... and I've made use of that myself when implementing/debugging
stubs/monitors. But in these cases, treating these events as SIGTRAP
possibly injects signals in the debuggee they'd never see otherwise,
because you need to use ptrace to enable these special events, which
aren't real signals.
There's more. Take this bit of handle_inferior_event, where we
determine whether a real signal (TARGET_WAITKIND_STOPPED) was random
or not:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
ecs->random_signal
= !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
GDB_SIGNAL_TRAP)
!= BPSTAT_SIGNAL_NO)
|| stopped_by_watchpoint
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
else
{
enum bpstat_signal_value sval;
sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
ecs->event_thread->suspend.stop_signal);
ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
}
Note that the
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
bit is only reacheable for signals != GDB_SIGNAL_TRAP. AFAICS, sval
can only be BPSTAT_SIGNAL_HIDE if nothing in the bpstat returns
BPSTAT_SIGNAL_PASS. So that excludes a "catch signal" for the signal
in question in the bpstat. All other catchpoints that aren't based on
breakpoints behind the scenes call process_event_stop_test directly
(don't pass through here) (well, almost all: TARGET_WAITKIND_LOADED
does have a fall through, but only for STOP_QUIETLY or
STOP_QUIETLY_NO_SIGSTOP, which still return before this code is
reached). Catchpoints that are implemented as breakpoints behind the
scenes can only appear in the bpstat if the signal was GDB_SIGNAL_TRAP
(bkpt_breakpoint_hit returns false otherwise). So that leaves a
target reporting a hardware watchpoint hit with a signal other than
GDB_SIGNAL_TRAP. And even then it looks quite wrong to me to
magically convert the signal into a GDB_SIGNAL_TRAP here too -- if the
user has set SIGTRAP to "handle pass", the program will see a trap
that gdb invented, not one the program would ever see without gdb in
the picture.
Tested on x86_64 Fedora 17.
gdb/
2013-10-31 Pedro Alves <palves@redhat.com>
* infrun.c (handle_syscall_event): Don't set or clear stop_signal.
(handle_inferior_event) <TARGET_WAITKIND_FORKED,
TARGET_WAITKIND_VFORKED>: Don't set stop_signal to
GDB_SIGNAL_TRAP, or clear it. Pass GDB_SIGNAL_0 to
bpstat_explains signal, instead of GDB_SIGNAL_TRAP.
<bpstat handling>: If the bpstat chain wants the signal to be
hidden, then set stop_signal to GDB_SIGNAL_0 instead of
GDB_SIGNAL_TRAP.
Now that all ecs->random_signal handing is always done before the
'process_event_stop_test' label, we can easily make that a real
function and actually give it a describing comment that somewhat makes
sense.
Reindenting the new function will be handled in a follow up patch.
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (process_event_stop_test): New function, factored out
from handle_inferior_event.
(handle_inferior_event): 'process_event_stop_test' is now a
function instead of a goto label -- adjust.
We only ever call "goto process_event_stop_test;" right after checking
that ecs->random_signal is clear. The code at the
process_event_stop_test label looks like:
/* For the program's own signals, act according to
the signal handling tables. */
if (ecs->random_signal)
{
... random signal handling ...
return;
}
else
{
... the stop tests that actually matter for the goto callers.
}
So this moves the label into the else branch. It'll make converting
process_event_stop_test into a function a bit clearer.
gdb/
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event): Move process_event_stop_test
goto label to the else branch of the ecs->random_signal check,
along with FRAME and GDBARCH re-fetching.
I recently added a new ecs->random_signal test after the "switch back to
stepped thread" code, and before the stepping tests. Looking at
making process_event_stop_test a proper function, I realized it'd be
better to keep ecs->random_signal related code together. To do that,
I needed to factor out the "switch back to stepped thread" code to a new
function, and call it in both the "random signal" and "not random
signal" paths.
gdb/
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (switch_back_to_stepped_thread): New function, factored
out from handle_inferior_event.
(handle_inferior_event): Adjust to call
switch_back_to_stepped_thread. Call it also at the tail of the
random signal handling, and return, instead of also handling
random signals just before the stepping tests.
'ecs' is always memset before being passed to handle_inferior_event.
The stop func is only filled in later in the flow. And since "Remove
dead sets/clears of ecs->random signal", nothing ever sets
ecs->random_signal before this part is reached either.
(Also tested with some added assertions in place.)
gdb/
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (clear_stop_func): Delete.
(handle_inferior_event): Don't call clear_stop_func and don't
clear 'ecs->random_signal'.
The other day while debugging something related to random signals, I
got confused with "set debug infrun 1" output, for it said:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal 20
On GNU/Linux, 20 is SIGTSTP. For some reason, it took me a few
minutes to realize that 20 is actually a GDB signal number, not a
target signal number (duh!). In any case, I propose making GDB's
output clearer here:
One way would be to use gdb_signal_to_name, like already used
elsewhere:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal SIGCHLD (20)
but I think that might confuse someone too ("20? Why does GDB believe
SIGCHLD is 20?"). So I thought of printing the enum string instead:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal GDB_SIGNAL_CHLD (20)
Looking at a more complete infrun debug log, we had actually printed
the (POSIX) signal name name a bit before:
infrun: target_wait (-1, status) =
infrun: 9300 [Thread 0x7ffff7fcb740 (LWP 9300)],
infrun: status->kind = stopped, signal = SIGCHLD
...
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal 20
So I'm now thinking that it'd be even better to make infrun output
consistently use the enum symbol string, like so:
infrun: clear_proceed_status_thread (Thread 0x7ffff7fca700 (LWP 25663))
infrun: clear_proceed_status_thread (Thread 0x7ffff7fcb740 (LWP 25659))
- infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
+ infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT, step=1)
- infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun: status->kind = stopped, signal = SIGCHLD
+ infrun: status->kind = stopped, signal = GDB_SIGNAL_CHLD
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x400700
- infrun: random signal 20
+ infrun: random signal (GDB_SIGNAL_CHLD)
infrun: random signal, keep going
- infrun: resume (step=1, signal=20), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_CHLD), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun: status->kind = stopped, signal = SIGTRAP
+ infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x400704
infrun: stepi/nexti
infrun: stop_stepping
GDB's signal numbers are public and hardcoded (see
include/gdb/signals.h), so there's really no need to clutter the
output with numeric values in some places while others not. Replacing
the magic "144" with GDB_SIGNAL_DEFAULT in "proceed"'s debug output
(see above) I think is quite nice.
I posit that all this makes it clearer to newcomers that GDB has its
own signal numbering (and that there must be some mapping going on).
Tested on x86_64 Fedora 17.
gdb/
2013-10-23 Pedro Alves <palves@redhat.com>
* common/gdb_signals.h (gdb_signal_to_symbol_string): Declare.
* common/signals.c: Include "gdb_assert.h".
(signals): New field 'symbol'.
(SET): Use the 'symbol' parameter.
(gdb_signal_to_symbol_string): New function.
* infrun.c (handle_inferior_event) <random signal>: In debug
output, print the random signal enum as string in addition to its
number.
* target/waitstatus.c (target_waitstatus_to_string): Print the
signal's enum value as string instead of the (POSIX) signal name.
'*ecs' is always memset by handle_inferior_event's callers, so all
these clears are unnecessary. There's one place that sets the flag to
true, but, afterwards, before ecs->random_signal is ever read, we
reach the part of handle_inferior_even that clears ecs->random_signal,
among other things:
clear_stop_func (ecs);
ecs->event_thread->stepping_over_breakpoint = 0;
bpstat_clear (&ecs->event_thread->control.stop_bpstat);
ecs->event_thread->control.stop_step = 0;
stop_print_frame = 1;
ecs->random_signal = 0;
stopped_by_random_signal = 0;
So all these ecs->random_signal accesses are dead code.
Tested on x86_64 Fedora 17.
gdb/
2013-10-22 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event) <thread hop>: Don't clear or
set ecs->random signal.
This function still has comments referring back to when it was a goto
label in wait_for_inferior, eons ago. Looking closer, actually most
of its comments could use a facelift (contents/formatting/typos).
That's what this patch does.
gdb/
2013-10-22 Pedro Alves <palves@redhat.com>
* infrun.c (keep_going): Update comments.
I noticed something odd while doing "stepi" over a fork syscall:
...
(gdb) set disassemble-next-line on
...
(gdb) si
0x000000323d4ba7c2 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
=> 0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
(gdb) si
0x000000323d4ba7c4 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
=> 0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
(gdb) si
0x000000323d4ba7c4 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
=> 0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
(gdb) si
0x000000323d4ba7ca 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
=> 0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
Notice how the third "si" didn't actually make progress.
Turning on infrun and lin-lwp debug, we see:
(gdb)
infrun: clear_proceed_status_thread (process 5252)
infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
infrun: resume (step=1, signal=0), trap_expected=0, current thread [process 5252] at 0x323d4ba7c4
LLR: Preparing to step process 5252, 0, inferior_ptid process 5252
RC: Not resuming sibling process 5252 (not stopped)
LLR: PTRACE_SINGLESTEP process 5252, 0 (resume event thread)
sigchld
infrun: wait_for_inferior ()
linux_nat_wait: [process -1], []
LLW: enter
LNW: waitpid(-1, ...) returned 5252, No child processes
LLW: waitpid 5252 received Child exited (stopped)
LLW: Candidate event Child exited (stopped) in process 5252.
SEL: Select single-step process 5252
LLW: exit
infrun: target_wait (-1, status) =
infrun: 5252 [process 5252],
infrun: status->kind = stopped, signal = SIGCHLD
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4ba7c4
infrun: random signal 20
infrun: stepi/nexti
infrun: stop_stepping
So the inferior got a SIGCHLD (because the fork child exited while
we're doing 'si'), and since that signal is set to "nostop noprint
pass" (by default), it's considered a random signal, so it should not
cause a stop. But, it resulted in an immediate a stop_stepping call
anyway. So the single-step never really finished.
This is a regression caused by:
[[PATCH] Do not respawn signals, take 2.]
https://sourceware.org/ml/gdb-patches/2012-06/msg00702.html
Specifically, caused by this change (as mentioned in the "the lost
step issue first" part of that mail):
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 53db335..3e8dbc8 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -4363,10 +4363,8 @@ process_event_stop_test:
(leaving the inferior at the step-resume-breakpoint without
actually executing it). Either way continue until the
breakpoint is really hit. */
- keep_going (ecs);
- return;
}
-
+ else
/* Handle cases caused by hitting a breakpoint. */
{
That made GDB fall through to the
> /* In all-stop mode, if we're currently stepping but have stopped in
> some other thread, we need to switch back to the stepped thread. */
> if (!non_stop)
part. However, if we don't have a stepped thread to get back to,
we'll now also fall through to all the "stepping" tests. For line
stepping, that'll turn out okay, as we'll just end up realizing the
thread is still in the stepping range, and needs to be re-stepped.
However, for stepi/nexti, we'll reach:
if (ecs->event_thread->control.step_range_end == 1)
{
/* It is stepi or nexti. We always want to stop stepping after
one instruction. */
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
ecs->event_thread->control.stop_step = 1;
print_end_stepping_range_reason ();
stop_stepping (ecs);
return;
}
and stop, even though the thread actually made no progress. The fix
is to restore the keep_going call, but put it after the "switch back
to the stepped thread" code, and before the stepping tests.
Tested on x86_64 Fedora 17, native and gdbserver. New test included.
gdb/
2013-10-18 Pedro Alves <palves@redhat.com>
PR gdb/16062
* infrun.c (handle_inferior_event): Keep going if we got a random
signal we should not stop for, instead of falling through to the
step tests.
gdb/testsuite/
2013-10-18 Pedro Alves <palves@redhat.com>
PR gdb/16062
* gdb.threads/stepi-random-signal.c: New file.
* gdb.threads/stepi-random-signal.exp: New file.
will hold the signal number when the inferior terminates due to the
uncaught signal.
I've made modifications on infrun.c:handle_inferior_event such that
$_exitcode gets cleared when the inferior signalled, and vice-versa.
This assumption was made because the variables are mutually
exclusive, i.e., when the inferior terminates because of an uncaught
signal it is not possible for it to return. I have also made modifications
such that when a corefile is loaded, $_exitsignal gets set to the uncaught
signal that "killed" the inferior, and $_exitcode is cleared.
The patch also adds a NEWS entry, documentation bits, and a testcase. The
documentation entry explains how to use $_exitsignal and $_exitcode in a
GDB script, by making use of the new $_isvoid convenience function.
gdb/
2013-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* NEWS: Mention new convenience variable $_exitsignal.
* corelow.c (core_open): Reset exit convenience variables. Set
$_exitsignal to the uncaught signal which generated the corefile.
* infrun.c (handle_inferior_event): Reset exit convenience
variables. Set $_exitsignal for TARGET_WAITKIND_SIGNALLED.
(clear_exit_convenience_vars): New function.
* inferior.h (clear_exit_convenience_vars): New prototype.
gdb/testsuite/
2013-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.base/corefile.exp: Test whether $_exitsignal is set and
$_exitcode is void when opening a corefile.
* gdb.base/exitsignal.exp: New file.
* gdb.base/segv.c: Likewise.
* gdb.base/normal.c: Likewise.
gdb/doc/
2013-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.texinfo (Convenience Variables): Document $_exitsignal.
Update entry for $_exitcode.
"info threads" changes the default source for "break" and "list", to
whatever the location of the first/bottom thread in the thread list
is...
(gdb) b start
(gdb) c
...
(gdb) list
*lists "start"*
(gdb) b 23
Breakpoint 3 at 0x400614: file test.c, line 23.
(gdb) info threads
Id Target Id Frame
* 2 Thread 0x7ffff7fcb700 (LWP 1760) "test" start (arg=0x0) at test.c:23
1 Thread 0x7ffff7fcc740 (LWP 1748) "test" 0x000000323dc08e60 in pthread_join (threadid=140737353922304, thread_return=0x0) at pthread_join.c:93
(gdb) b 23
Breakpoint 4 at 0x323dc08d90: file pthread_join.c, line 23.
^^^^^^^^^^^^^^^
(gdb) list
93 lll_wait_tid (pd->tid);
94
95
96 /* Restore cancellation mode. */
97 CANCEL_RESET (oldtype);
98
99 /* Remove the handler. */
100 pthread_cleanup_pop (0);
101
102
The issue is that print_stack_frame always sets the current sal to the
frame's sal. print_frame_info (which print_stack_frame calls to do
most of the work) also sets the last displayed sal, but only if
print_what isn't LOCATION. Now the call in question, from within
thread.c:print_thread_info, does pass in LOCATION as print_what, but
print_stack_frame doesn't have the same check print_frame_info has.
We could consider adding it, but setting these globals depending on
print_what isn't very clean, IMO. What we have is two logically
distinct operations mixed in the same function(s):
#1 - print frame, in the format specified by {print_what,
print_level and print_args}.
#2 - We're displaying a frame to the user, and I want the default
sal to point here, because the program stopped here, or the user
did some context-changing command (up, down, etc.).
So I added a new parameter to print_stack_frame & friends for point
#2, and went through all calls in the tree adjusting as necessary.
Tested on x86_64 Fedora 17.
gdb/
2013-09-17 Pedro Alves <palves@redhat.com>
PR gdb/15911
* ada-tasks.c (task_command_1): Adjust call to print_stack_frame.
* bsd-kvm.c (bsd_kvm_open, bsd_kvm_proc_cmd, bsd_kvm_pcb_cmd):
* corelow.c (core_open):
* frame.h (print_stack_frame, print_frame_info): New
'set_current_sal' parameter.
* infcmd.c (finish_command, kill_command): Adjust call to
print_stack_frame.
* inferior.c (inferior_command): Likewise.
* infrun.c (normal_stop): Likewise.
* linux-fork.c (linux_fork_context): Likewise.
* record-full.c (record_full_goto_entry, record_full_restore):
Likewise.
* remote-mips.c (common_open): Likewise.
* stack.c (print_stack_frame): New 'set_current_sal' parameter.
Use it.
(print_frame_info): New 'set_current_sal' parameter. Set the last
displayed sal depending on the new paremeter instead of looking at
print_what.
(backtrace_command_1, select_and_print_frame, frame_command)
(current_frame_command, up_command, down_command): Adjust call to
print_stack_frame.
* thread.c (print_thread_info, restore_selected_frame)
(do_captured_thread_select): Adjust call to print_stack_frame.
* tracepoint.c (tfind_1): Likewise.
* mi/mi-cmd-stack.c (mi_cmd_stack_list_frames)
(mi_cmd_stack_info_frame): Likewise.
* mi/mi-interp.c (mi_on_normal_stop): Likewise.
* mi/mi-main.c (mi_cmd_exec_return, mi_cmd_trace_find): Likewise.
gdb/testsuite/
* gdb.threads/info-threads-cur-sal-2.c: New file.
* gdb.threads/info-threads-cur-sal.c: New file.
* gdb.threads/info-threads-cur-sal.exp: New file.
detach_fork.
* inf-ptrace.c (inf_ptrace_follow_fork): Likewise.
* inf-ttrace.c (inf_ttrace_follow_fork): Likewise.
* inferior.h (detach_fork): Remove.
* infrun.c (detach_fork): Adjust comment and make it
static.
(follow_fork): Pass detach_fork parameter to
target_follow_fork.
* linux-nat.c (linux_child_follow_fork): New parameter
detach_fork.
* target.c (target_follow_fork): New parameter detach_fork.
Pass detach_fork as parameter and print its value.
* target.h (struct target_ops) <to_follow_fork>: New int
parameter.
(target_follow_fork): New parameter detach_fork.
Declare it close to other related declarations in utils.h, and remove
local extern declaration hack.
gdb/
2013-06-28 Pedro Alves <palves@redhat.com>
* infrun.c (set_observer_mode): Don't declare pagination_enabled
here.
* utils.h (pagination_enabled): Declare.
The "non_stop_1" global is out of place, mixed with the observer bits.
This moves all the non-stop user-interface-related bits together.
gdb/
2013-06-28 Pedro Alves <palves@redhat.com>
* infrun.c (non_stop, non_stop_1, set_non_stop, show_non_stop):
Move higher up in file.
This whole comment is now a bit out of place. I looked into moving it
to handle_inferior_event, close to where in_solib_dynsym_resolve_code
is used, but then there are 3 such places. I then looked at
fragmenting it, pushing bits closer to the definitions of
in_solib_dynsym_resolve_code and gdbarch_skip_solib_resolver, but then
we'd lose the main advantage which is the overview. In the end, I
realized this can fit nicely as internals manual material.
This could possibly be a subsection of a new "run control", or "source
stepping" or "stepping" or some such a bit more general section, but
we can do that when we have more related content... Even the "single
stepping" section is presently empty...
gdb/doc/
2013-06-27 Pedro Alves <palves@redhat.com>
* gdbint.texinfo (Algorithms) <Stepping over runtime loader
dynamic symbol resolution code>: New section, based on infrun.c
comment.
gdb/
2013-06-27 Pedro Alves <palves@redhat.com>
* infrun.c: Remove comment describing the 'stepping over runtime
loader dynamic symbol resolution code' mechanism; moved to
gdbint.texinfo.
This hasn't been used for years.
gdb/
2013-06-26 Pedro Alves <palves@redhat.com>
* infrun.c (SOLIB_IN_DYNAMIC_LINKER): Delete macro and describing
comment.
This updates the comments on the step-over-resolver mechanism a bit,
adjusting it to refer to the gdbarch hooks instead of the old macros;
to mention the in_dynsym_resolve_code hook of the target_so_ops
vector; and to American English spelling (signalling->signaling).
gdb/
2013-06-26 Pedro Alves <palves@redhat.com>
* infrun.c: Update comments on stepping over runtime loader
dynamic symbol resolution code.
This fixes PR cli/15603.
The bug here is that when a software watchpoint is being used, gdb
will stop responding to C-c. This is a regression caused by the
"catch signal" patch.
The problem is that software watchpoints always end up on the bpstat
list. However, this makes bpstat_explains_signal return
BPSTAT_SIGNAL_HIDE, causing infrun to think that the signal is not a
"random signal".
The fix is to change bpstat_explains_signal to handle this better. I
chose to do it in a "clean API" way, by passing the signal value to
bpstat_explains_signal and then adding an explains_signal method for
watchpoints, which handles the specifics.
Built and regtested on x86-64 Fedora 18.
New test case included.
* break-catch-sig.c (signal_catchpoint_explains_signal): Add 'sig'
argument.
* breakpoint.c (bpstat_explains_signal): Add 'sig' argument.
Special case signals other than GDB_SIGNAL_TRAP.
(explains_signal_watchpoint): New function.
(base_breakpoint_explains_signal): Add 'sig' argument.
(initialize_breakpoint_ops): Set 'explains_signal' method for
watchpoints.
* breakpoint.h (struct breakpoint_ops) <explains_signal>: Add
signal argument.
(bpstat_explains_signal): Likewise.
* infrun.c (handle_syscall_event, handle_inferior_event): Update.
* gdb.base/random-signal.c: New file.
* gdb.base/random-signal.exp: New file.
* breakpoint.h (handle_solib_event): Moved function declaration
to solib.h.
* breakpoint.c (handle_solib_event): Moved function to solib.c.
(bpstat_stop_status): Pass new argument to handle_solib_event.
* solib.h (update_solib_breakpoints): New function declaration.
(handle_solib_event): Moved function declaration from
breakpoint.h.
* solib.c (update_solib_breakpoints): New function.
(handle_solib_event): Moved function from breakpoint.c.
Updated to call solib_ops->handle_event if not NULL.
* solist.h (target_so_ops): New fields "update_breakpoints" and
"handle_event".
* infrun.c (set_stop_on_solib_events): New function.
(_initialize_infrun): Use the above for "set
stop-on-solib-events".
(handle_inferior_event): Pass new argument to handle_solib_event.
* solib-svr4.c (probe.h): New include.
(svr4_free_library_list): New forward declaration.
(probe_action): New enum.
(probe_info): New struct.
(probe_info): New static variable.
(NUM_PROBES): New definition.
(svr4_info): New fields "using_xfer", "probes_table" and
"solib_list".
(free_probes_table): New function.
(free_solib_list): New function.
(svr4_pspace_data_cleanup): Free probes table and solib list.
(svr4_copy_library_list): New function.
(svr4_current_sos_via_xfer_libraries): New parameter "annex".
(svr4_read_so_list): New parameter "prev_lm".
(svr4_current_sos_direct): Renamed from "svr4_current_sos".
(svr4_current_sos): New function.
(probe_and_action): New struct.
(hash_probe_and_action): New function.
(equal_probe_and_action): Likewise.
(register_solib_event_probe): Likewise.
(solib_event_probe_at): Likewise.
(solib_event_probe_action): Likewise.
(solist_update_full): Likewise.
(solist_update_incremental): Likewise.
(disable_probes_interface_cleanup): Likewise.
(svr4_handle_solib_event): Likewise.
(svr4_update_solib_event_breakpoint): Likewise.
(svr4_update_solib_event_breakpoints): Likewise.
(svr4_create_solib_event_breakpoints): Likewise.
(enable_break): Free probes table before creating breakpoints.
Use svr4_create_solib_event_breakpoints to create breakpoints.
(svr4_solib_create_inferior_hook): Free the solib list.
(_initialize_svr4_solib): Initialise
svr4_so_ops.handle_solib_event and svr4_so_ops.update_breakpoints.
This fixes some of the problems in infrun.c that the checker reported.
I filed the remaining problems as bugs.
This patch is purely stylistic.
* infrun.c (adjust_pc_after_break): Introduce an outer null
cleanup.
This patch teaches GDB to take advantage of target-assisted range
stepping. It adds a new 'r ADDR1,ADDR2' action to vCont (vCont;r),
meaning, "step once, and keep stepping as long as the thread is in the
[ADDR1,ADDR2) range".
Rationale:
When user issues the "step" command on the following line of source,
a = b + c + d * e - a;
GDB single-steps every single instruction until the program reaches a
new different line. E.g., on x86_64, that line compiles to:
0x08048434 <+65>: mov 0x1c(%esp),%eax
0x08048438 <+69>: mov 0x30(%esp),%edx
0x0804843c <+73>: add %eax,%edx
0x0804843e <+75>: mov 0x18(%esp),%eax
0x08048442 <+79>: imul 0x2c(%esp),%eax
0x08048447 <+84>: add %edx,%eax
0x08048449 <+86>: sub 0x34(%esp),%eax
0x0804844d <+90>: mov %eax,0x34(%esp)
0x08048451 <+94>: mov 0x1c(%esp),%eax
and the following is the RSP traffic between GDB and GDBserver:
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:3c840408;thread:p2e13.2e13;core:1;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:3e840408;thread:p2e13.2e13;core:2;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:42840408;thread:p2e13.2e13;core:2;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:47840408;thread:p2e13.2e13;core:0;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:49840408;thread:p2e13.2e13;core:0;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:4d840408;thread:p2e13.2e13;core:0;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:51840408;thread:p2e13.2e13;core:0;
IOW, a lot of roundtrips between GDB and GDBserver.
If we add a new command to the RSP, meaning "keep stepping and don't
report a stop until the program goes out of the [0x08048434,
0x08048451) address range", then the RSP traffic can be reduced down
to:
--> vCont;r8048434,8048451:p2db0.2db0;c
<-- T0505:68efffbf;04:30efffbf;08:51840408;thread:p2db0.2db0;core:1;
As number of packets is reduced dramatically, the performance of
stepping source lines is much improved.
In case something is wrong with range stepping on the stub side, the
debug info or even gdb, this adds a "set/show range-stepping" command
to be able to turn range stepping off.
gdb/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdbthread.h (struct thread_control_state) <may_range_step>: New
field.
* infcmd.c (step_once, until_next_command): Enable range stepping.
* infrun.c (displaced_step_prepare): Disable range stepping.
(resume): Disable range stepping if stepping over a breakpoint or
we have software watchpoints. If range stepping is enabled,
assert the thread is in the stepping range.
(clear_proceed_status_thread): Clear may_range_step.
(handle_inferior_event): Disable range stepping as soon as we know
the thread that hit the event. Re-enable it whenever we're going
to step with a step range.
* remote.c (struct vCont_action_support) <r>: New field.
(use_range_stepping): New global.
(remote_vcont_probe): Handle 'r' action.
(append_resumption): Append an 'r' action if the thread may range
step.
(show_range_stepping): New function.
(set_range_stepping): New function.
(_initialize_remote): Call add_setshow_boolean_cmd to register the
'set range-stepping' and 'show range-stepping' commands.
* NEWS: Mention range stepping, the new vCont;r action, and the
new "set/show range-stepping" commands.
gdb/doc/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdb.texinfo (Packets): Document 'vCont;r'.
(Continuing and Stepping): Document target-assisted range
stepping, and the 'set range-stepping' and 'show range-stepping'
commands.
This adds a function for doing within-thread's-stepping-range checks,
and converts a couple spots to use it. Following patches will add
more uses.
gdb/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdbthread.h (pc_in_thread_step_range): New declaration.
* thread.c (pc_in_thread_step_range): New function.
* infrun.c (handle_inferior_event): Use it.
This is sort of a continuation of Keith's parse_exp_1 constification
patch. It started out by undoing these bits:
@@ -754,9 +754,12 @@ validate_actionline (char **line, struct
tmp_p = p;
for (loc = t->base.loc; loc; loc = loc->next)
{
- p = tmp_p;
- exp = parse_exp_1 (&p, loc->address,
+ const char *q;
+
+ q = tmp_p;
+ exp = parse_exp_1 (&q, loc->address,
block_for_pc (loc->address), 1);
+ p = (char *) q;
and progressively making more things const upwards, fixing fallout,
rinse repeat, until GDB built again (--enable-targets=all).
That ended up constifying lookup_cmd/add_cmd and (lots of) friends,
and the completers.
I didn't try to constify the command hooks themselves, because I know
upfront there are commands that write to the command string argument,
and I think I managed to stop at a nice non-hacky split point already.
I think the only non-really-super-obvious changes are
tracepoint.c:validate_actionline, and tracepoint.c:trace_dump_actions.
The rest is just mostly about 'char *' => 'const char *', 'char **'=>
'const char **', and the occasional (e.g., deprecated_cmd_warning)
case of 'char **'=> 'const char *', where/when I noticed that nothing
actually cares about the pointer to pointer output.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2013-03-13 Pedro Alves <palves@redhat.com>
* ada-lang.c (struct add_partial_datum) <text, text0, word>: Make
fields const.
(ada_make_symbol_completion_list): Make "text0" parameter const.
* ax-gdb.c (agent_eval_command_one): Make "exp" parameter const.
* breakpoint.c (condition_completer): Make "text" and "word"
parameters const. Adjust.
(check_tracepoint_command): Adjust to validate_actionline
prototype change.
(catch_syscall_completer): Make "text" and "word" parameters
const.
* cli/cli-cmds.c (show_user): Make "comname" local const.
(valid_command_p): Make "command" parameter const.
(alias_command): Make "alias_prefix" and "command_prefix" locals
const.
* cli/cli-decode.c (add_cmd): Make "name" parameter const.
(add_alias_cmd): Make "name" and "oldname" parameters const.
Adjust. No longer make copy of OLDNAME.
(add_prefix_cmd, add_abbrev_prefix_cmd, add_set_or_show_cmd)
(add_setshow_cmd_full, add_setshow_enum_cmd)
(add_setshow_auto_boolean_cmd, add_setshow_boolean_cmd)
(add_setshow_filename_cmd, add_setshow_string_cmd)
(add_setshow_string_noescape_cmd)
(add_setshow_optional_filename_cmd, add_setshow_integer_cmd)
(add_setshow_uinteger_cmd, add_setshow_zinteger_cmd)
(add_setshow_zuinteger_unlimited_cmd, add_setshow_zuinteger_cmd)
(delete_cmd, add_info, add_info_alias, add_com, add_com_alias):
Make "name" parameter const.
(help_cmd): Rename "command" parameter to "arg". New const local
"command".
(find_cmd): Make "command" parameter const.
(lookup_cmd_1): Make "text" parameter pointer to const. Adjust to
deprecated_cmd_warning prototype change.
(undef_cmd_error): Make "cmdtype" parameter const.
(lookup_cmd): Make "line" parameter const.
(deprecated_cmd_warning): Change type of "text" parameter to
pointer to const char, from pointer to pointer to char. Adjust.
(lookup_cmd_composition): Make "text" parameter const.
(complete_on_cmdlist, complete_on_enum): Make "text" and "word"
parameters const.
* cli/cli-decode.h (struct cmd_list_element) <name>: Make field
const.
* cli/cli-script.c (validate_comname): Make "tem" local const.
(define_command): New const local "tem_c". Use it in calls to
lookup_cmd.
(document_command): Make "tem" and "comfull" locals const.
(show_user_1): Make "prefix" and "name" parameters const.
* cli-script.h (show_user_1): Make "prefix" and "name" parameters
const.
* command.h (add_cmd, add_alias_cmd, add_prefix_cmd)
(add_abbrev_prefix_cmd, completer_ftype, lookup_cmd, lookup_cmd_1)
(deprecated_cmd_warning, lookup_cmd_composition, add_com)
(add_com_alias, add_info, add_info_alias, complete_on_cmdlist)
(complete_on_enum, add_setshow_enum_cmd)
(add_setshow_auto_boolean_cmd, add_setshow_boolean_cmd)
(add_setshow_filename_cmd, add_setshow_string_cmd)
(add_setshow_string_noescape_cmd)
(add_setshow_optional_filename_cmd, add_setshow_integer_cmd)
(add_setshow_uinteger_cmd, add_setshow_zinteger_cmd)
(add_setshow_zuinteger_cmd, add_setshow_zuinteger_unlimited_cmd):
Change prototypes, constifying strings.
* completer.c (noop_completer, filename_completer): Make "text"
and "prefix" parameters const.
(location_completer, expression_completer)
(complete_line_internal): Make "text" and "prefix" parameters
const and adjust.
(command_completer, signal_completer): Make "text" and "prefix"
parameters const.
* completer.h (noop_completer, filename_completer)
(expression_completer, location_completer, command_completer)
(signal_completer): Change prototypes.
* corefile.c (complete_set_gnutarget): Make "text" and "word"
parameters const.
* cp-abi.c (cp_abi_completer): Likewise.
* expression.h (parse_expression_for_completion): Change
prototype.
* f-lang.c (f_make_symbol_completion_list): Make "text" and "word"
parameters const.
* infcmd.c (_initialize_infcmd): Make "cmd_name" local const.
* infrun.c (handle_completer): Make "text" and "word" parameters
const.
* interps.c (interpreter_completer): Make "text" and "word"
parameters const.
* language.h (struct language_defn)
<la_make_symbol_completion_list>: Make "text" and "word"
parameters const.
* parse.c (parse_exp_1): Move const hack to parse_exp_in_context.
(parse_exp_in_context): Rename to ...
(parse_exp_in_context_1): ... this.
(parse_exp_in_context): Reimplement, with const hack from
parse_exp_1.
(parse_expression_for_completion): Make "string" parameter const.
* printcmd.c (decode_format): Make "string_ptr" parameter pointer
to pointer to const char. Adjust.
(print_command_1): Make "exp" parameter const.
(output_command): Rename to ...
(output_command_const): ... this. Make "exp" parameter const.
(output_command): Reimplement.
(x_command): Adjust.
(display_command): Rename "exp" parameter to "arg". New "exp"
local, const version of "arg".
* python/py-auto-load.c (gdbpy_initialize_auto_load): Make
"cmd_name" local const.
* python/py-cmd.c (cmdpy_destroyer): Cast const away in xfree
call.
(cmdpy_completer): Make "text" and "word" parameters const.
(gdbpy_parse_command_name): Make "prefix_text2" local const.
* python/py-param.c (add_setshow_generic): Make "tmp_name" local
const.
* remote.c (_initialize_remote): Make "cmd_name" local const.
* symtab.c (language_search_unquoted_string): Make "text" and "p"
parameters const. Adjust.
(completion_list_add_fields): Make "sym_text", "text" and "word"
parameters const.
(struct add_name_data) <sym_text, text, word>: Make fields const.
(default_make_symbol_completion_list_break_on): Make "text" and
"word" parameters const. Adjust locals.
(default_make_symbol_completion_list)
(make_symbol_completion_list, make_symbol_completion_type)
(make_symbol_completion_list_fn): Make "text" and "word"
parameters const.
(make_file_symbol_completion_list): Make "text", "word" and
"srcfile" parameters const. Adjust locals.
(add_filename_to_list): Make "text" and "word" parameters const.
(struct add_partial_filename_data) <text, word>: Make fields
const.
(make_source_files_completion_list): Make "text" and "word"
parameters const.
* symtab.h (default_make_symbol_completion_list_break_on)
(default_make_symbol_completion_list, make_symbol_completion_list)
(make_symbol_completion_type enum type_code)
(make_symbol_completion_list_fn make_file_symbol_completion_list)
(make_source_files_completion_list): Change prototype.
* top.c (execute_command): Adjust to pass pointer to pointer to
const char to lookup_cmd, and to deprecated_cmd_warning prototype
change.
(set_verbose): Make "cmdname" local const.
* tracepoint.c (decode_agent_options): Make "exp" parameter const,
and adjust.
(validate_actionline): Make "line" parameter a pointer to const
char, and adjust.
(encode_actions_1): Make "action_exp" local const, and adjust.
(encode_actions): Adjust.
(replace_comma): Delete.
(trace_dump_actions): Make "action_exp" and "next_comma" locals
const, and adjust. Don't frob the action string while splitting
it at commas. Instead, make a copy of each split substring in
turn.
(trace_dump_command): Adjust to validate_actionline prototype
change.
* tracepoint.h (decode_agent_options, decode_agent_options)
(encode_actions, validate_actionline): Change prototypes.
* valprint.h (output_command): Delete declaration.
(output_command_const): Declare.
* value.c (function_destroyer): Cast const away in xfree call.
gdb/
* record-full.h, record-full.c (record_memory_query): Rename
to ...
(record_full_memory_query): ...this. Update all users.
(record_arch_list_add_reg): Rename to ...
(record_full_arch_list_add_reg): ...this. Update all users.
(record_arch_list_add_mem): Rename to ...
(record_full_arch_list_add_mem): ...this. Update all users.
(record_arch_list_add_end): Rename to ...
(record_full_arch_list_add_end): ...this. Update all users.
(record_gdb_operation_disable_set): Rename to ...
(record_full_gdb_operation_disable_set): ...this.
Update all users.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* breakpoint.c (breakpoint_re_set): Remove the skip_re_set call.
* infrun.c (handle_inferior_event): Rename the called function to
function_name_is_marked_for_skip, pass it TMP_SAL.
* skip.c (struct skiplist_entry): Update function_name comment. Remove
fields pc, gdbarch and pending.
(skip_function_pc): Rename this forward declaration to ...
(skip_function): ... here.
(skip_file_command): Remove variable pending and its use, remove
initialization of E fields pending and gdbarch. Do not use SYMTAB
filename, use the specified one.
(skip_function_command): Remove variable func_pc, do not set it.
Update the caller of skip_function. Replace decode_line_1 call by
a lookup_symbol call. Remove variables orig_arg, decode_exception and
sals. Update the caller of skip_function.
(skip_info): Remove variable address_width and its use. Do not print
address (PC). Renumber column 5 to 4.
(skip_function_pc): Rename to ...
(skip_function): ... here and remove its parameters pc, arch and
pending. Update the function comment and no longer use those
parameters.
(function_pc_is_marked_for_skip): Rename to ...
(function_name_is_marked_for_skip): ... here, update function comment
just to a skip.h reference, replace pc parameter by function_name and
function_sal. No longer use E field pending and pc. Remove variables
searched_for_sal, sal and filename. Call compare_filenames_for_search
instead of just strcmp.
(skip_re_set): Remove the function.
* skip.h (struct symtab_and_line): New declaration.
(function_pc_is_marked_for_skip): Rename to ...
(function_name_is_marked_for_skip): ... here, replace pc parameter by
function_name and function_sal, update the function comment.
gdb/testsuite/
* gdb.base/skip-solib.exp (info skip with pending file): Update the
expected output.
(info skip with pending file): Remove.
(ignoring function in solib, info skip for function multiply): Update
the expected output.
* gdb.base/skip.ex (skip (main), skip function baz, info skip)
(info skip (delete 1), info skip after disabling all)
(info skip after enabling all, info skip after disabling 4 2-3)
(info skip after enabling 2-3, info skip 2-3)
(info skip after deleting 2 3): Update the expected output.
* gdb.linespec/base/two/thefile.cc (n): New variable v, split the
statement to its initialization and return.
* gdb.linespec/skip-two.exp: New file.
Pedro Alves
Ulrich Weigand
Markus Metzger
Tom Tromey
Joel Brobecker
Yao Qi
Sergio Durigan Junior
Luis Machado
Markus Metzger
Gary Benson
Joel Brobecker
Aleksandar Ristovski
Jan Kratochvil