Remove old-style function header variants from sepdebug.c. Eliminate
references to the removed locations "breakpoint 9" and "breakpoint 13"
from sepdebug.exp.
gdb/testsuite/ChangeLog:
* gdb.base/sepdebug.c: Remove #ifdef PROTOTYPES, keep prototyped
variant.
* gdb.base/sepdebug.exp: Drop references to removed code.
Remove old-style function header variants from list0.h and list1.c.
Fill the removed lines with comments or empty lines, such that the
line numbering is undisturbed. Changes to the line numbering would
require heavy adjustments to list.exp, where many line numbers are
hard-coded, as well as a fair amount of knowledge about the source
code in and around certain lines. Thus the dependency on the line
numbering can not be eliminated so easily, and it may not even be a
useful goal for a "list" test case. Another option might be to adjust
the literal line numbers in list.exp, but even that is not as
straightforward as it may seem, since the test case expects certain
source lines to be exactly n lines apart.
gdb/testsuite/ChangeLog:
* gdb.base/list0.h: Remove #ifdef PROTOTYPES, keep prototyped
variant. Preserve original line numbering.
* gdb.base/list1.c: Likewise.
Remove old-style function headers from break.c and break1.c. Adjust
break.exp accordingly; in particular eliminate references to the
removed locations "breakpoint 9, 13, and 16" from break.exp.
gdb/testsuite/ChangeLog:
* gdb.base/break.c: Remove #ifdef PROTOTYPES, keep prototyped
variant.
* gdb.base/break1.c: Likewise.
* gdb.base/break.exp: Drop references to removed code.
The previous patch did not indent perform_all_tests() correctly after
moving the main logic into it, to avoid obscuring the functional
changes. This patch fixes the indentation.
gdb/testsuite/ChangeLog:
* gdb.base/callfuncs.exp (perform_all_tests): Re-indent.
In callfuncs.exp, compile callfuncs.c with and without C function
header prototypes and execute all tests after each compilation.
gdb/testsuite/ChangeLog:
* gdb.base/callfuncs.exp: Remove 'prototypes' variable. Move main
logic into perform_all_tests() and invoke it with and without
function header prototypes.
(do_function_calls): Remove conditional XFAIL for PR 5318.
(rerun_and_prepare): Remove duplicate code.
(perform_all_tests): New. Main logic moved here.
The C source file for the 'callfuncs' test case did not compile with
-DNO_PROTOTYPES or -DPROTOTYPES. This patch fixes various syntax
errors under #ifdef NO_PROTOTYPES and a small typo under #ifdef
PROTOTYPES.
gdb/testsuite/ChangeLog:
* gdb.base/callfuncs.c (t_float_many_args): Fix syntax error in
code guarded by #ifdef NO_PROTOTYPES.
(t_double_many_args): Likewise.
(DEF_FUNC_MANY_ARGS_1): Likewise.
(DEF_FUNC_VALUES_1): Likewise.
(t_structs_ldc): Renamed from t_structs_fc in conditional code
guarded by #ifdef PROTOTYPES.
Remove the literal line number from a regexp in mi-console.exp. Add
an appropriate eye-catcher to mi-console.c and refer to that instead.
gdb/testsuite/ChangeLog:
* gdb.mi/mi-console.c: Add eye-catcher.
* gdb.mi/mi-console.exp (semihosted_string): Refer to eye-catcher
instead of literal line number.
Remove the literal line number from a regexp in shlib-call.exp. Add
an appropriate eye-catcher to shr2.c and refer to that instead.
gdb/testsuite/ChangeLog:
* gdb.base/shr2.c: Add eye-catcher.
* gdb.base/shlib-call.exp: Refer to eye-catcher instead of literal
line number.
Remove literal line numbers from the regexps in jump.exp. Add
appropriate eye-catchers to jump.c and refer to those instead.
gdb/testsuite/ChangeLog:
* gdb.base/jump.c: Add eye-catchers.
* gdb.base/jump.exp: Refer to eye-catchers instead of literal line
numbers.
Remove literal line numbers from the regexps in foll-exec.exp. Add
appropriate eye-catchers to foll-exec.c and execd-proc.c and refer to
those instead.
gdb/testsuite/ChangeLog:
* gdb.base/execd-prog.c: Add eye-catchers.
* gdb.base/foll-exec.c: Likewise.
* gdb.base/foll-exec.exp: Refer to eye-catchers instead of literal
line numbers.
Remove literal line numbers from the regexps in ending-run.exp. Add
appropriate eye-catchers to ending-run.c and refer to those instead.
gdb/testsuite/ChangeLog:
* gdb.base/ending-run.c: Add eye-catchers.
* gdb.base/ending-run.exp: Refer to eye-catchers instead of
literal line numbers.
Remove literal line numbers from the regexps in call-rt-st.exp. Add
appropriate eye-catchers to call-rt-st.c and refer to those instead.
gdb/testsuite/ChangeLog:
* gdb.base/call-rt-st.c: Add eye-catchers.
* gdb.base/call-rt-st.exp: Refer to eye-catchers instead of
literal line numbers.
Remove literal line numbers from the regexps in call-ar-st.exp. Add
appropriate eye-catchers to call-ar-st.c and refer to those instead.
gdb/testsuite/ChangeLog:
* gdb.base/call-ar-st.c: Add eye-catchers.
* gdb.base/call-ar-st.exp: Refer to eye-catchers instead of
literal line numbers.
Remove literal line numbers from the commands and regexps in dbx.exp.
Add appropriate eye-catchers to average.c and sum.c and refer to those
instead.
gdb/testsuite/ChangeLog:
* gdb.base/average.c: Add eye-catchers.
* gdb.base/sum.c: Likewise.
* gdb.base/dbx.exp: Use eye-catchers to determine line numbers for
regexps dynamically.
Remove literal line numbers from the regexps in so-impl-ld.exp. Add
appropriate eye-catchers to solib1.c and refer to those instead.
gdb/testsuite/ChangeLog:
* gdb.base/solib1.c: Add eye-catchers.
* gdb.base/so-impl-ld.exp: Match against eye-catchers instead of
literal line numbers.
As no place in the backends check cont_thread anymore, we can stop
setting and clearing it in places that resume the target and wait for
events. Instead simply clear it whenever a new GDB connects.
gdb/gdbserver/
2014-11-12 Pedro Alves <palves@redhat.com>
* server.c (cont_thread): Update comment.
(start_inferior, attach_inferior): No longer clear cont_thread.
(handle_v_cont): No longer set cont_thread.
(captured_main): Clear cont_thread each time a GDB connects.
There's code in linux_wait_1 that resumes all threads if the Hc thread
disappears. It's the wrong thing to do, as GDB has told GDBserver to
resume only one thread, because e.g., the user has scheduler-locking
enabled, or because GDB was stepping the program over a breakpoint.
Resuming all threads behind GDB's back can't be good in either case.
The right thing to do is to detect that that the (only) resumed thread
is gone, and let GDB know about it. The Linux backend is already
doing that nowadays, since:
commit fa96cb382c
Author: Pedro Alves <palves@redhat.com>
AuthorDate: Thu Feb 27 14:30:08 2014 +0000
Teach GDBserver's Linux backend about no unwaited-for children (TARGET_WAITKIND_NO_RESUMED).
The backend detects that all resumed threads have disappeared, and
returns TARGET_WAITKIND_NO_RESUMED to the core of GDBserver, which
then reports an error to GDB.
There's no need to frob the passed in ptid to wait for the continue
thread either -- linux_wait_for_event only returns events for resumed
threads.
The badness (of resuming threads) can actually be observed in the
testsuite, if we force-disable vCont support in GDBserver -- before
the patch, gdb.threads/no-unwaited-for-left.exp hangs if we disable
vCont:
(gdb) continue
Continuing.
FAIL: gdb.threads/no-unwaited-for-left.exp: continue to breakpoint: break-here (timeout)
... more cascading timeouts ....
After the patch, gdb.threads/no-unwaited-for-left.exp behaves the same
with or without vCont support:
(gdb) continue
Continuing.
[New Thread 32226]
[Switching to Thread 32226]
Breakpoint 2, thread_a (arg=0x0) at /home/pedro/gdb/mygit/build/../src/gdb/testsuite/gdb.threads/no-unwaited-for-left.c:28
28 return 0; /* break-here */
(gdb) PASS: gdb.threads/no-unwaited-for-left.exp: continue to breakpoint: break-here
...
continue
Continuing.
warning: Remote failure reply: E.No unwaited-for children left.
[Thread 32222] #1 stopped.
(gdb) FAIL: gdb.threads/no-unwaited-for-left.exp: continue stops when the main thread exits
Overall, this is also good for getting rid of a RSP detail from the backend.
gdb/gdbserver/
2014-11-12 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_wait_1): Don't force a wait for the Hc
thread, and don't resume all threads if the Hc thread has exited.
The target->request_interrupt callback implements the handling for
ctrl-c. User types ctrl-c in GDB, GDB sends a \003 to the remote
target, and the remote targets stops the program with a SIGINT, just
like if the user typed ctrl-c in GDBserver's terminal.
The trouble is that using kill_lwp(signal_pid, SIGINT) sends the
SIGINT directly to the program's main thread. If that thread has
exited already, then that kill won't do anything.
Instead, send the SIGINT to the process group, just like GDB
does (see inf-ptrace.c:inf_ptrace_stop).
gdb.threads/leader-exit.exp is extended to cover the scenario. It
fails against GDBserver before the patch.
Tested on x86_64 Fedora 20, native and GDBserver.
gdb/gdbserver/
2014-11-12 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_request_interrupt): Always send a SIGINT to
the process group instead of to a specific LWP.
gdb/testsuite/
2014-11-12 Pedro Alves <palves@redhat.com>
* gdb.threads/leader-exit.exp: Test sending ctrl-c works after the
leader has exited.
No longer used since the non-continuable watchpoints handling rework.
gdb/
2014-11-12 Pedro Alves <palves@redhat.com>
* infrun.c (enum infwait_states, infwait_state): Delete.
The gdb.arch/i386-bp_permanent.exp test is currently failing an
assertion recently added:
(gdb) stepi
../../src/gdb/infrun.c:2237: internal-error: resume: Assertion `sig != GDB_SIGNAL_0' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
FAIL: gdb.arch/i386-bp_permanent.exp: Single stepping past permanent breakpoint. (GDB internal error)
The assertion expects that the only reason we currently need to step a
breakpoint instruction is when we have a signal to deliver. But when
stepping a permanent breakpoint (with or without a signal) we also
reach this code.
The assertion is correct and the permanent breakpoints skipping code
is wrong.
Consider the case of the user doing "step/stepi" when stopped at a
permanent breakpoint. GDB's `resume' calls the
gdbarch_skip_permanent_breakpoint hook and then happily continues
stepping:
/* Normally, by the time we reach `resume', the breakpoints are either
removed or inserted, as appropriate. The exception is if we're sitting
at a permanent breakpoint; we need to step over it, but permanent
breakpoints can't be removed. So we have to test for it here. */
if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
{
gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
}
But since gdbarch_skip_permanent_breakpoint already advanced the PC
manually, this ends up executing the instruction that is _after_ the
breakpoint instruction. The user-visible result is that a single-step
steps two instructions.
The gdb.arch/i386-bp_permanent.exp test is actually ensuring that
that's indeed how things work. It runs to an int3 instruction, does
"stepi", and checks that "leave" was executed with that "stepi". Like
this:
(gdb) b *0x0804848c
Breakpoint 2 at 0x804848c
(gdb) c
Continuing.
Breakpoint 2, 0x0804848c in standard ()
(gdb) disassemble
Dump of assembler code for function standard:
0x08048488 <+0>: push %ebp
0x08048489 <+1>: mov %esp,%ebp
0x0804848b <+3>: push %edi
=> 0x0804848c <+4>: int3
0x0804848d <+5>: leave
0x0804848e <+6>: ret
0x0804848f <+7>: nop
(gdb) si
0x0804848e in standard ()
(gdb) disassemble
Dump of assembler code for function standard:
0x08048488 <+0>: push %ebp
0x08048489 <+1>: mov %esp,%ebp
0x0804848b <+3>: push %edi
0x0804848c <+4>: int3
0x0804848d <+5>: leave
=> 0x0804848e <+6>: ret
0x0804848f <+7>: nop
End of assembler dump.
(gdb)
One would instead expect that a stepi at 0x0804848c stops at
0x0804848d, _before_ the "leave" is executed. This commit changes GDB
this way. Care is taken to make stepping into a signal handler when
the step starts at a permanent breakpoint instruction work correctly.
The patch adjusts gdb.arch/i386-bp_permanent.exp in this direction,
and also makes it work on x86_64 (currently it only works on i*86).
The patch also adds a new gdb.base/bp-permanent.exp test that
exercises many different code paths related to stepping permanent
breakpoints, including the stepping with signals cases. The test uses
"hack/trick" to make it work on all (or most) platforms -- it doesn't
really hard code a breakpoint instruction.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-11-12 Pedro Alves <palves@redhat.com>
* infrun.c (resume): Clear the thread's 'stepped_breakpoint' flag.
Rewrite stepping over a permanent breakpoint.
(thread_still_needs_step_over, proceed): Don't set
stepping_over_breakpoint for permanent breakpoints.
(handle_signal_stop): Don't clear stepped_breakpoint. Also pull
single-step breakpoints out of the target on hardware step
targets.
(process_event_stop_test): If stepping a permanent breakpoint
doesn't hit the step-resume breakpoint, delete the step-resume
breakpoint.
(switch_back_to_stepped_thread): Also check if the stepped thread
has advanced already on hardware step targets.
(currently_stepping): Return true if the thread stepped a
breakpoint.
gdb/testsuite/
2014-11-12 Pedro Alves <palves@redhat.com>
* gdb.arch/i386-bp_permanent.c: New file.
* gdb.arch/i386-bp_permanent.exp: Don't skip on x86_64.
(srcfile): Set to i386-bp_permanent.c.
(top level): Adjust to work in both 32-bit and 64-bit modes. Test
that stepi does not execute the 'leave' instruction, instead of
testing it does execute.
* gdb.base/bp-permanent.c: New file.
* gdb.base/bp-permanent.exp: New file.
"permanent"-ness is currently a property of the breakpoint. But, it
should actually be an implementation detail of a _location_. Consider
this bit in infrun.c:
/* Normally, by the time we reach `resume', the breakpoints are either
removed or inserted, as appropriate. The exception is if we're sitting
at a permanent breakpoint; we need to step over it, but permanent
breakpoints can't be removed. So we have to test for it here. */
if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
{
if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
else
error (_("\
The program is stopped at a permanent breakpoint, but GDB does not know\n\
how to step past a permanent breakpoint on this architecture. Try using\n\
a command like `return' or `jump' to continue execution."));
}
This will wrongly skip a non-breakpoint instruction if we have a
multiple location breakpoint where the whole breakpoint was set to
"permanent" because one of the locations happened to be permanent,
even if the one GDB is resuming from is not.
Related, because the permanent breakpoints are only marked as such in
init_breakpoint_sal, we currently miss marking momentary breakpoints
as permanent. A test added by a following patch trips on that.
Making permanent-ness be per-location, and marking locations as such
in add_location_to_breakpoint, the natural place to do this, fixes
this issue...
... and then exposes a latent issue with mark_breakpoints_out. It's
clearing the inserted flag of permanent breakpoints. This results in
assertions failing like this:
Breakpoint 1, main () at testsuite/gdb.base/callexit.c:32
32 return 0;
(gdb) call callexit()
[Inferior 1 (process 15849) exited normally]
gdb/breakpoint.c:12854: internal-error: allegedly permanent breakpoint is not actually inserted
A problem internal to GDB has been detected,
further debugging may prove unreliable.
The call dummy breakpoint, which is a momentary breakpoint, is set on
top of a manually inserted breakpoint instruction, and so is now
rightfully marked as a permanent breakpoint. See "Write a legitimate
instruction at the point where the infcall breakpoint is going to be
inserted." comment in infcall.c.
Re. make_breakpoint_permanent. That's only called by solib-pa64.c.
Permanent breakpoints were actually originally invented for HP-UX [1].
I believe that that call (the only one in the tree) is unnecessary
nowadays, given that nowadays the core breakpoints code analyzes the
instruction under the breakpoint to automatically detect whether it's
setting a breakpoint on top of a breakpoint instruction in the
program. I know close to nothing about HP-PA/HP-UX, though.
[1] https://sourceware.org/ml/gdb-patches/1999-q3/msg00245.html, and
https://sourceware.org/ml/gdb-patches/1999-q3/msg00242.html
In addition to the per-location issue, "permanent breakpoints" are
currently always displayed as enabled=='n':
(gdb) b main
Breakpoint 3 at 0x40053c: file ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S, line 29.
(gdb) info breakpoints
Num Type Disp Enb Address What
3 breakpoint keep n 0x000000000040053c ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S:29
But OTOH they're always enabled; there's no way to disable them...
In turn, this means that if one adds commands to such a breakpoint,
they're _always_ run:
(gdb) start
Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.arch/i386-permbkpt
...
Temporary breakpoint 1, main () at ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S:29
29 int3
(gdb) b main
Breakpoint 2 at 0x40053c: file ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S, line 29.
(gdb) info breakpoints
Num Type Disp Enb Address What
2 breakpoint keep n 0x000000000040053c ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S:29
(gdb) commands
Type commands for breakpoint(s) 2, one per line.
End with a line saying just "end".
>echo "hello!"
>end
(gdb) disable 2
(gdb) start
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Temporary breakpoint 3 at 0x40053c: file ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S, line 29.
Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.arch/i386-permbkpt
Breakpoint 2, main () at ../../../src/gdb/testsuite/gdb.arch/i386-permbkpt.S:29
29 int3
"hello!"(gdb)
IMO, one should be able to disable such a breakpoint, and GDB should
then behave just like if the user hadn't created the breakpoint in the
first place (that is, report a SIGTRAP).
By making permanent-ness a property of the location, and eliminating
the bp_permanent enum enable_state state ends up fixing that as well.
No tests are added for these changes yet; they'll be added in a follow
up patch, as skipping permanent breakpoints is currently broken and
trips on an assertion in infrun.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
2014-11-12 Pedro Alves <palves@redhat.com>
Mark locations as permanent, not the whole breakpoint.
* breakpoint.c (remove_breakpoint_1, remove_breakpoint): Adjust.
(mark_breakpoints_out): Don't mark permanent breakpoints as
uninserted.
(breakpoint_init_inferior): Use mark_breakpoints_out.
(breakpoint_here_p): Adjust.
(bpstat_stop_status, describe_other_breakpoints): Remove handling
of permanent breakpoints.
(make_breakpoint_permanent): Mark each location as permanent,
instead of marking the breakpoint.
(add_location_to_breakpoint): If the location is permanent, mark
it as such, and as inserted.
(init_breakpoint_sal): Don't make the breakpoint permanent here.
(bp_location_compare, update_global_location_list): Adjust.
(update_breakpoint_locations): Don't make the breakpoint permanent
here.
(disable_breakpoint, enable_breakpoint_disp): Don't skip permanent
breakpoints.
* breakpoint.h (enum enable_state) <bp_permanent>: Delete field.
(struct bp_location) <permanent>: New field.
* guile/scm-breakpoint.c (bpscm_enable_state_to_string): Remove
reference to bp_permanent.
breakpoint.c uses gdbarch_breakpoint_from_pc to determine whether a
breakpoint location points at a permanent breakpoint:
static int
bp_loc_is_permanent (struct bp_location *loc)
{
...
addr = loc->address;
bpoint = gdbarch_breakpoint_from_pc (loc->gdbarch, &addr, &len);
...
if (target_read_memory (loc->address, target_mem, len) == 0
&& memcmp (target_mem, bpoint, len) == 0)
retval = 1;
...
So I think we should default the gdbarch_skip_permanent_breakpoint
hook to advancing the PC by the length of the breakpoint instruction,
as determined by gdbarch_breakpoint_from_pc. I believe that simple
implementation does the right thing for most architectures. If
there's an oddball architecture where that doesn't work, then it
should override the hook, just like it should be overriding the hook
if there was no default anyway.
The only two implementation of skip_permanent_breakpoint are
i386_skip_permanent_breakpoint, for x86, and
hppa_skip_permanent_breakpoint, for PA-RISC/HP-UX
The x86 implementation is trivial, and can clearly be replaced by the
new default.
I don't know about the HP-UX one though, I know almost nothing about
PA. It may well be advancing the PC ends up being equivalent.
Otherwise, it must be that "jump $pc_after_bp" doesn't work either...
Tested on x86_64 Fedora 20 native and gdbserver.
gdb/
2014-11-12 Pedro Alves <palves@redhat.com>
* arch-utils.c (default_skip_permanent_breakpoint): New function.
* arch-utils.h (default_skip_permanent_breakpoint): New
declaration.
* gdbarch.sh (skip_permanent_breakpoint): Now an 'f' function.
Install default_skip_permanent_breakpoint as default method.
* i386-tdep.c (i386_skip_permanent_breakpoint): Delete function.
(i386_gdbarch_init): Don't install it.
* infrun.c (resume): Assume there's always a
gdbarch_skip_permanent_breakpoint implementation.
* gdbarch.h, gdbarch.c: Regenerate.
Linux supports multiple "PID namespaces". Processes in different PID
namespaces have different views of the system process list. Sometimes,
a single process can appear in more than one PID namespace, but with a
different PID in each. When GDB and its target are in different PID
namespaces, various features can break due to the mismatch between
what the target believes its PID to be and what GDB believes its PID
to be. The most visible broken functionality is thread enumeration
silently failing.
This patch explicitly warns users against trying to debug across PID
namespaces.
The patch introduced no new failures in my test suite run on an x86_64
installation of Ubuntu 14.10. It doesn't include a test: writing an
automated test that exercises this code would be very involved because
CLONE_NEWNS requires CAP_SYS_ADMIN; the easier way to reproduce the
problem is to start a new lxc container.
gdb/
2014-11-11 Daniel Colascione <dancol@dancol.org>
Warn about cross-PID-namespace debugging.
* nat/linux-procfs.h (linux_proc_pid_get_ns): New prototype.
* nat/linux-procfs.c (linux_proc_pid_get_ns): New function.
* linux-thread-db.c (check_pid_namespace_match): New function.
(thread_db_inferior_created): Call it.
When searching static symbols, gdb would search over all
expanded symtabs of all objfiles, and if that fails only then
would it search all partial/gdb_index tables of all objfiles.
This means that the user could get a random instance of the
symbol depending on what symtabs have been previously expanded.
Now the search is consistent, searching each objfile completely
before proceeding to the next one.
gdb/ChangeLog:
PR symtab/17564
* symtab.c (lookup_symbol_in_all_objfiles): Delete.
(lookup_static_symbol): Move definition to new location and rewrite.
(lookup_symbol_in_objfile): New function.
(lookup_symbol_global_iterator_cb): Call it.
gdb/testsuite/ChangeLog:
PR symtab/17564
* gdb.base/symtab-search-order.exp: New file.
* gdb.base/symtab-search-order.c: New file.
* gdb.base/symtab-search-order-1.c: New file.
* gdb.base/symtab-search-order-shlib-1.c: New file.
A recent change to eval.c triggered a GCC bug that causes a false positive
"may be used uninitialized" warning in evaluate_subexp_standard. This seems
to be triggered by a specific CFG constructed via setjmp and gotos.
While the GCC bug is in the process of being fixed, there are released
compiler versions (in particular GCC 4.9) in the field that show this
problem. In order to allow compiling GDB with one of those compilers,
this commit slightly reworks the CFG (in an equivalent way) of the
affected function, so that the GCC bug is no longer triggered.
gdb/ChangeLog:
* eval.c (evaluate_subexp_standard): Work around GCC bug 63748.
Running gdb.base/sigstep.exp with --target=i686-pc-linux-gnu on a
64-bit kernel naturally trips on PR gdb/17511 as well, given this is a
kernel bug.
I haven't really tested a real 32-bit kernel/machine, but given the
code in question in the kernel is shared between 32-bit and 64-bit,
I'm quite sure the bug triggers in those cases as well.
So, simply xfail i?86-*-linux* too.
gdb/testsuite/
2014-11-07 Pedro Alves <palves@redhat.com>
PR gdb/17511
* gdb.base/sigstep.exp (in_handler_map) <si+advance>: xfail
i?86-*-linux*.
The in_prologue check in the nexti code is obsolete; this commit
removes that, and then removes the in_prologue function as nothing
else uses it.
Looking at the code in GDB that makes use in_prologue, all we find is
this one caller:
if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
|| ((ecs->event_thread->control.step_range_end == 1)
&& in_prologue (gdbarch, ecs->event_thread->prev_pc,
ecs->stop_func_start)))
{
/* I presume that step_over_calls is only 0 when we're
supposed to be stepping at the assembly language level
("stepi"). Just stop. */
/* Also, maybe we just did a "nexti" inside a prolog, so we
thought it was a subroutine call but it was not. Stop as
well. FENN */
/* And this works the same backward as frontward. MVS */
end_stepping_range (ecs);
return;
}
This was added by:
commit 100a02e1de
...
From Fernando Nasser:
* infrun.c (handle_inferior_event): Handle "nexti" inside function
prologues.
The mailing list thread is here:
https://sourceware.org/ml/gdb-patches/2001-01/msg00047.html
Not much discussion there, and no test, but looking at the code around
what was patched in that revision, we see that the checks that detect
whether the program has just stepped into a subroutine didn't rely on
the unwinders at all back then.
From 'git show 100a02e1:gdb/infrun.c':
if (stop_pc == ecs->stop_func_start /* Quick test */
|| (in_prologue (stop_pc, ecs->stop_func_start) &&
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
!IN_SOLIB_RETURN_TRAMPOLINE (stop_pc, ecs->stop_func_name))
|| IN_SOLIB_CALL_TRAMPOLINE (stop_pc, ecs->stop_func_name)
|| ecs->stop_func_name == 0)
{
/* It's a subroutine call. */
if ((step_over_calls == STEP_OVER_NONE)
|| ((step_range_end == 1)
&& in_prologue (prev_pc, ecs->stop_func_start)))
{
/* I presume that step_over_calls is only 0 when we're
supposed to be stepping at the assembly language level
("stepi"). Just stop. */
/* Also, maybe we just did a "nexti" inside a prolog,
so we thought it was a subroutine call but it was not.
Stop as well. FENN */
stop_step = 1;
print_stop_reason (END_STEPPING_RANGE, 0);
stop_stepping (ecs);
return;
}
Stripping the IN_SOLIB_RETURN_TRAMPOLINE checks for simplicity, we had:
if (stop_pc == ecs->stop_func_start /* Quick test */
|| in_prologue (stop_pc, ecs->stop_func_start)
|| ecs->stop_func_name == 0)
{
/* It's a subroutine call. */
That is, detecting a subroutine call was based on prologue detection
back then. So the in_prologue check in the current tree only made
sense back then as it was undoing a bad decision the in_prologue check
that used to exist above did.
Today, the check for a subroutine call relies on frame ids instead,
which are stable throughout the function. So we can just remove the
in_prologue check for nexti, and the whole in_prologue function along
with it.
Tested on x86_64 Fedora 20, and also by nexti-ing manually a prologue.
gdb/
2014-11-07 Pedro Alves <palves@redhat.com>
* infrun.c (process_event_stop_test) <subroutine check>: Don't
check if we did a "nexti" inside a prologue.
* symtab.c (in_prologue): Delete function.
* symtab.h (in_prologue): Delete declaration.
"aux" doesn't contribute anything to the name, and it makes the
reader wonder what it's supposed to mean.
gdb/ChangeLog:
* symtab.c (lookup_local_symbol): Renamed from lookup_symbol_aux_local.
All callers updated.
(lookup_symbol_in_all_objfiles): Renamed from
lookup_symbol_aux_symtabs. All callers updated.
(lookup_symbol_via_quick_fns): Renamed from lookup_symbol_aux_quick.
All callers updated.
(lookup_symbol_in_objfile_symtabs): Renamed from
lookup_symbol_aux_objfile. All callers updated.
and lookup_static_symbol_aux to lookup_static_symbol.
gdb/ChangeLog:
* symtab.c (lookup_static_symbol): Renamed from
lookup_static_symbol_aux. All callers updated.
(lookup_symbol_in_static_block): Renamed from lookup_symbol_static.
All callers updated.
gdb/ChangeLog:
* block.h (ALL_BLOCK_SYMBOLS_WITH_NAME): New macro.
* block.c (block_lookup_symbol): Use it.
* cp-support.c (make_symbol_overload_list_block): Use it.
* symtab.c (iterate_over_symbols): Use it.
There is another function, lookup_symbol_aux_block, and
the names lookup_block_symbol and lookup_symbol_aux_block don't
convey any real difference between them.
The difference is that lookup_block_symbol lives in the lower level
block API, and lookup_symbol_aux_block lives in the higher level symtab API.
This patch makes this distinction clear.
gdb/ChangeLog:
* symtab.c (lookup_block_symbol): Moved to ...
* block.c (block_lookup_symbol): ... here and renamed.
All callers updated.
* block.h (block_lookup_symbol): Declare.
* symtab.h (lookup_block_symbol): Delete.
Non-primary symtabs share the block vector with their primary symtabs.
In these cases there's no need to use ALL_SYMTABS.
gdb/ChangeLog:
* ada-lang.c (ada_make_symbol_completion_list): Use
ALL_PRIMARY_SYMTABS instead of ALL_SYMTABS.
* symtab.c (lookup_objfile_from_block): Ditto.
obstack_next_free is supposed to return a void*, rather than a char*
as it does currently. Avoid warning on void* arithmetic when
obstack_next_free gets it proper return type.
* cp-valprint.c (cp_print_value_fields): Cast obstack_next_free
to char* before doing pointer arithmetic.
obstack_blank isn't the correct macro to call for shrinking obstacks
since it does size checking.
* charset.c (convert_between_encodings): Shrink obstack using
obstack_blank_fast.
* minsyms.c (install_minimal_symbols): Likewise.
