Eclipse CDT now supports enabling execution recording using two methods
(full and btrace) and both formats for btrace (bts and pt). In the
event that recording is enabled behind the back of the GUI (by the user
on the command line, or a script), we need to know which method/format
are being used, so it can be correctly reflected in the interface. This
patch adds this information to the =record-started async record.
Before:
=record-started,thread-group="i1"
After:
=record-started,thread-group="i1",method="btrace",format="bts"
=record-started,thread-group="i1",method="btrace",format="pt"
=record-started,thread-group="i1",method="full"
The "format" field is only present when the current method supports
multiple formats (only the btrace method as of now).
gdb/ChangeLog:
* NEWS: Mention the new fields in =record-started.
* common/btrace-common.h (btrace_format_short_string): New function
declaration.
* common/btrace-common.c (btrace_format_short_string): New
function.
* mi/mi-interp.c (mi_record_changed): Output method and format
fields in the =record-started record.
* record-btrace.c (record_btrace_open): Adapt record_changed
notification.
* record-full.c (record_full_open): Likewise.
* record.c (cmd_record_stop): Likewise.
gdb/doc/ChangeLog:
* gdb.texinfo (GDB/MI Async Records): Document method and
format fields in =record-started.
* observer.texi (record_changed): Add method and format
parameters.
gdb/testsuite/ChangeLog:
* gdb.mi/mi-record-changed.exp: Adjust =record-started output
matching.
gdb/ChangeLog:
2016-06-02 Jon Turney <jon.turney@dronecode.org.uk>
* windows-nat.c (handle_output_debug_string): Return type of
gdb_signal_from_host() is gdb_signal, not an int.
(windows_get_exec_module_filename): Add pointer casts for C++.
gdb/gdbserver/ChangeLog:
2016-06-02 Jon Turney <jon.turney@dronecode.org.uk>
* win32-low.c (win32_create_inferior): Add pointer casts for C++.
This fixes PR python/18984.
The bug is that gdbpy_solib_name uses GDB_PY_LL_ARG, whereas it should
use GDB_PY_LLU_ARG to avoid overflow.
Built and tested on x86-64 Fedora 23.
2016-06-02 Tom Tromey <tom@tromey.com>
PR python/18984:
* python/python.c (gdbpy_solib_name): Use GDB_PY_LLU_ARG.
2016-06-02 Tom Tromey <tom@tromey.com>
PR python/18984:
* gdb.python/py-shared.exp: Add solib_name test.
... and fix Ctrl-C races.
The current remote-fileio.c SIGINT/EINTR code can lose Ctrl-C --
there's a period where SIG_IGN is installed as signal handler, for
example.
Since:
- remote.c no longer installs a custom SIGINT handler;
- The current remote-fileio.c SIGINT handler is basically the same as
the default SIGINT handler (event-top.c:handle_sigint), in
principle, except that instead of setting the quit flag, it sets a
separate flag.
I think we should be able to completely remove the remote-fileio.c
SIGINT handler, and centralize on the quit flag, thus fixing the
Ctrl-C race.
gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>
* remote-fileio.c (remote_fio_ctrl_c_flag, remote_fio_sa)
(remote_fio_osa)
(remote_fio_ofunc, remote_fileio_sig_init, remote_fileio_sig_set)
(remote_fileio_sig_exit, remote_fileio_ctrl_c_signal_handler):
Delete.
(remote_fileio_o_quit_handler): New global.
(remote_fileio_quit_handler): New function.
(remote_fileio_reply): Check the quit flag instead of the custom
'remote_fio_ctrl_c_flag' flag. Restore the quit handler instead
of changing the SIGINT handler.
(do_remote_fileio_request): Override the quit handler instead of
changing the SIGINT handler.
Patch 7eb895307f Skip unwritable frames in command "finish"
skips non-writable frames in addition to tailcall frames.
If skip_tailcall_frames already returns NULL, skip_unwritable_frames
will be called with a NULL frame and crash in get_frame_arch. This is
caught by gdb.btrace/tailcall-only.exp.
Further, if we ever end up with a mixture of tailcall and non-writable
frames, we may not skip all of them, as intended.
Loop over skip_tailcall_frames and skip_unwritable_frames as long as at least
one of them makes progress.
gdb/
* infcmd.c (skip_finish_frames): New.
(finish_command): Call skip_finish_frames.
As reported in PR 19998, after type ctrl-c, GDB hang there and does
not send interrupt. It causes a fail in gdb.base/interrupt.exp.
All targets support remote fileio should be affected.
When we type ctrc-c, SIGINT is handled by remote_fileio_sig_set,
as shown below,
#0 remote_fileio_sig_set (sigint_func=0x4495d0 <remote_fileio_ctrl_c_signal_handler(int)>) at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:325
#1 0x00000000004495de in remote_fileio_ctrl_c_signal_handler (signo=<optimised out>) at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:349
#2 <signal handler called>
#3 0x00007ffff647ed83 in __select_nocancel () at ../sysdeps/unix/syscall-template.S:81
#4 0x00000000005530ce in interruptible_select (n=10, readfds=readfds@entry=0x7fffffffd730, writefds=writefds@entry=0x0, exceptfds=exceptfds@entry=0x0,
timeout=timeout@entry=0x0) at /home/yao/SourceCode/gnu/gdb/git/gdb/event-top.c:1017
#5 0x000000000061ab20 in stdio_file_read (file=<optimised out>, buf=0x12d02e0 "\n\022-\001", length_buf=16383)
at /home/yao/SourceCode/gnu/gdb/git/gdb/ui-file.c:577
#6 0x000000000044a4dc in remote_fileio_func_read (buf=0x12c0360 "") at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:583
#7 0x0000000000449598 in do_remote_fileio_request (uiout=<optimised out>, buf_arg=buf_arg@entry=0x12c0340)
at /home/yao/SourceCode/gnu/gdb/git/gdb/remote-fileio.c:1179
we don't set quit_serial_event,
do
{
res = gdb_select (n, readfds, writefds, exceptfds, timeout);
}
while (res == -1 && errno == EINTR);
if (res == 1 && FD_ISSET (fd, readfds))
{
errno = EINTR;
return -1;
}
return res;
we can't go out of the loop above, and that is why GDB can't send
interrupt.
Recently, we stop throwing exception from SIGINT handler
(remote_fileio_ctrl_c_signal_handler)
https://sourceware.org/ml/gdb-patches/2016-03/msg00372.html, which
is correct, because gdb_select is interruptible. However, in the
same patch series, we add interruptible_select later as a wrapper
to gdb_select, https://sourceware.org/ml/gdb-patches/2016-03/msg00375.html
and it is not interruptible (because of the loop in it) unless
select/poll-able file descriptors are marked.
This fix in this patch is to call quit_serial_event_set, so that we can
go out of the loop above, return -1 and set errno to EINTR.
2016-06-01 Yao Qi <yao.qi@linaro.org>
PR remote/19998
* remote-fileio.c (remote_fileio_ctrl_c_signal_handler): Call
quit_serial_event_set.
https://sourceware.org/bugzilla/show_bug.cgi?id=19893
I've traced the main source of the problem to pieced_value_funcs.coerce_ref not being
implemented. Since gdb always assumes references are implemented as pointers, this
causes it to think that it's dealing with a NULL pointer, thus breaking any operations
involving synthetic references.
What I did here was implementing pieced_value_funcs.coerce_ref using some of the synthetic
pointer handling code from indirect_pieced_value, as Pedro suggested. I also made a few
adjustments to the reference printing code so that it correctly shows either the address
of the referenced value or (if it's non-addressable) the "<synthetic pointer>" string.
I also wrote some unit tests based on Dwarf::assemble; these took a while to make
because in most cases I needed a synthetic reference to a physical variable. Additionally,
I started working on a unit test for classes that have a vtable, but ran into a few issues
so that'll probably go in a future patch. One thing that should definitely be fixed is that
proc function_range (called for MACRO_AT_func) will always try to compile/link using gcc
with the default options instead of g++, thus breaking C++ compilations that require e.g. libstdc++.
gdb/ChangeLog:
* dwarf2loc.c (coerce_pieced_ref, indirect_synthetic_pointer,
fetch_const_value_from_synthetic_pointer): New functions.
(indirect_pieced_value): Move lower half to indirect_synthetic_pointer.
(pieced_value_funcs): Implement coerce_ref.
* valops.c (value_addr): Call coerce_ref for synthetic references.
* valprint.c (valprint_check_validity): Return true for synthetic
references. Also, don't show "<synthetic pointer>" if they reference
addressable values.
(generic_val_print_ref): Handle synthetic references. Also move some
code to print_ref_address.
(print_ref_address, get_value_addr_contents): New functions.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/implref.exp: Rename to...
* gdb.dwarf2/implref-const.exp: ...this. Also add more test statements.
* gdb.dwarf2/implref-array.c: New file.
* gdb.dwarf2/implref-array.exp: Likewise.
* gdb.dwarf2/implref-global.c: Likewise.
* gdb.dwarf2/implref-global.exp: Likewise.
* gdb.dwarf2/implref-struct.c: Likewise.
* gdb.dwarf2/implref-struct.exp: Likewise.
Local variables in lambdas are not accessible
https://sourceware.org/bugzilla/show_bug.cgi?id=15231
GDB: read_lexical_block_scope
/* Ignore blocks with missing or invalid low and high pc attributes. */
[...]
if (!dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL))
return;
But sometimes there is:
FAIL: gcc-5.3.1-6.fc23.x86_64
<2><92>: Abbrev Number: 11 (DW_TAG_lexical_block)
<3><9c>: Abbrev Number: 13 (DW_TAG_structure_type)
<9d> DW_AT_name : (indirect string, offset: 0x3c): <lambda()>
[...]
Where DW_TAG_lexical_block has no attributes. Such whole subtree is currently
dropped by GDB while I think it should just import all its children DIEs.
It even XFAIL->XPASSes gdb.ada/out_of_line_in_inlined.exp:
commit 0fa7fe506c
Author: Joel Brobecker <brobecker@adacore.com>
out of line functions nested inside inline functions.
So I have removed that xfail.
gdb/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* dwarf2read.c (enum pc_bounds_kind): Add PC_BOUNDS_INVALID.
(process_psymtab_comp_unit_reader, read_func_scope): Adjust callers.
(read_lexical_block_scope): Import DIEs from bare DW_TAG_lexical_block.
(read_call_site_scope): Adjust callers.
(dwarf2_get_pc_bounds): Implement pc_bounds_invalid.
(dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds): Adjust callers.
gdb/testsuite/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* gdb.ada/out_of_line_in_inlined.exp: Remove xfails.
* gdb.dwarf2/dw2-lexical-block-bare.exp: New file.
Make the code (maybe) more readable + primarily prepare it for [patch 2/2]
enum extension.
This change should have no code change impact.
gdb/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
Code cleanup: dwarf2_get_pc_bounds: -1/0/+1 -> enum
* dwarf2read.c (enum pc_bounds_kind) New.
(dwarf2_get_pc_bounds): Use it in the declaration.
(process_psymtab_comp_unit_reader): Adjust caller. Rename has_pc_info
to cu_bounds_kind.
(read_func_scope, read_lexical_block_scope, read_call_site_scope):
Adjust callers.
(dwarf2_get_pc_bounds): Use enum pc_bounds_kind in the definition.
(dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds): Adjust callers.
Standardize the QCatchSyscalls NEWS entry.
gdb/ChangeLog
2016-05-29 Jan Kratochvil <jan.kratochvil@redhat.com>
* NEWS (QCatchSyscalls): Remove the parameter. Include ...
(QCatchSyscalls:1 in qSupported) ... this separate entry which got
deleted.
When evaluating an expression with EVAL_AVOID_SIDE_EFFECTS if the value
we return is forced to be of type not_lval then GDB will be unable to
take the address of the returned value.
Instead, we should properly initialise the LVAL of the returned value.
This commit builds on two previous commits 2520f728b7 (Forward
VALUE_LVAL when avoiding side effects for STRUCTOP_STRUCT) and
ac775bf4d3 (gdb: Forward VALUE_LVAL when avoiding side effects for
STRUCTOP_PTR), which in turn build on ac1ca910d7 (Fixes for PR
exp/15364).
This commit is currently untested due to my lack of access to an OpenCL
compiler, however, if follows the same pattern as the first two commits
mentioned above and so I believe that it is correct.
gdb/ChangeLog:
* opencl-lang.c (evaluate_subexp_opencl): If
EVAL_AVOID_SIDE_EFFECTS mode, forward the VALUE_LVAL attribute to
the returned value in the STRUCTOP_STRUCT case.
Assume that we have a C program like this:
struct foo_type
{
int var;
} foo;
struct foo_type *foo_ptr = &foo;
int
main ()
{
return foo_ptr->var;
}
Then GDB should be able to evaluate the following, however, it currently
does not:
(gdb) start
...
(gdb) whatis &(foo_ptr->var)
Attempt to take address of value not located in memory.
The problem is that in EVAL_AVOID_SIDE_EFFECTS mode,
eval.c:evaluate_subexp_standard always returns a not_lval value as the
result for a STRUCTOP_PTR operation. As a consequence, the rest of
the code believes that one cannot take the address of the returned
value.
This patch fixes STRUCTOP_PTR handling so that the VALUE_LVAL
attribute for the returned value is properly initialized. After this
change, the above session becomes:
(gdb) start
...
(gdb) whatis &(foo_ptr->var)
type = int *
This commit is largely the same as commit 2520f728b7 (Forward
VALUE_LVAL when avoiding side effects for STRUCTOP_STRUCT) but applied
to STRUCTOP_PTR rather than STRUCTOP_STRUCT. Both of these commits are
building on top of commit ac1ca910d7 (Fixes for PR exp/15364).
gdb/ChangeLog:
* eval.c (evaluate_subexp_standard): If EVAL_AVOID_SIDE_EFFECTS
mode, forward the VALUE_LVAL attribute to the returned value in
the STRUCTOP_PTR case.
gdb/testsuite/ChangeLog:
* gdb.base/whatis.c: Extend the test case.
* gdb.base/whatis.exp: Add additional tests.
Ulrich pointed out that an earlier patch had misspelled
HAVE_LIBPYTHON2_4, adding an extra "_". This caused a build failure.
This patch fixes the bug.
2016-05-25 Tom Tromey <tom@tromey.com>
* python/py-value.c (value_object_as_number): Use correct spelling
of HAVE_LIBPYTHON2_4.
Variable "show" was hardcoded to zero for pointer and reference types.
This implementation didn't allow a correct "whatis" print
for those types and results in same output for "ptype" and "whatis".
Before:
(gdb) whatis t3p
type = PTR TO -> ( Type t3
integer(kind=4) :: t3_i
Type t2 :: t2_n
End Type t3 )
After:
(gdb) whatis t3p
type = PTR TO -> ( Type t3 )
2016-05-25 Bernhard Heckel <bernhard.heckel@intel.com>
gdb/Changelog:
* f-typeprint.c (f_type_print_base): Replace 0 by show.
gdb/testsuite/Changelog:
* gdb.fortran/type.f90: Add pointer variable.
* gdb.fortran/whatis_type.exp: Add whatis/ptype of pointers.
According to the typeprint's description, the level of details is
decreased by one for the typeprint of elements of a structure.
Before:
(gdb) ptype t3v
type = Type t3
integer(kind=4) :: t3_i
Type t2
integer(kind=4) :: t2_i
Type t1
integer(kind=4) :: t1_i
real(kind=4) :: t1_r
End Type t1 :: t1_n
End Type t2 :: t2_n
End Type t3
After:
(gdb) ptype t3v
type = Type t3
integer(kind=4) :: t3_i
Type t2 :: t2_n
End Type t3
2016-05-25 Bernhard Heckel <bernhard.heckel@intel.com>
gdb/Changelog:
* f-typeprint.c (f_type_print_base): Decrease show by one.
gdb/testsuite/Changelog:
* gdb.fortran/type.f90: Add nested structures.
* gdb.fortran/whatis-type.exp: Whatis/ptype nested structures.
* gdb.fortran/derived-type.exp: Adapt expected output.
* gdb.fortran/vla-type.exp: Adapt expected output.
According to the typeprint's description, elements of a structure
should not be printed when show is < 1.
This variable is also used to distinguish the level of details
between "ptype" and "whatis" expressions.
Before:
(gdb) whatis t1v
type = Type t1
integer(kind=4) :: t1_i
real(kind=4) :: t1_r
End Type t1
After:
(gdb) whatis t1v
type = Type t1
2016-05-25 Bernhard Heckel <bernhard.heckel@intel.com>
gdb/Changelog:
* f-typeprint.c (f_type_print_base): Don't print fields when show < 0.
gdb/testsuite/Changelog:
* gdb.fortran/whatis_type.exp: Adapt expected output.
Level of indentation was not proper handled when printing
the elements type's name.
Before:
type = Type t1
integer(kind=4) :: var_1
integer(kind=4) :: var_2
End Type t1
After:
type = Type t1
integer(kind=4) :: var_1
integer(kind=4) :: var_2
End Type t1
2016-05-25 Bernhard Heckel <bernhard.heckel@intel.com>
gdb/Changelog:
* f-typeprint.c (f_type_print_base): Take print level into account.
gdb/testsuite/Changelog:
* gdb.fortran/print_type.exp: Fix expected output.
* gdb.fortran/whatis_type.exp: Fix expected output.
This patch fixes PR python/17386.
The bug is that gdb.Value does not implement the Python __index__
method. This method is needed to convert a Python object to an index
and is used by various operations in Python, such as indexing an
array.
The fix is to implement the nb_index method for gdb.Value.
nb_index was added in Python 2.5. I don't have a good way to test
Python 2.4, but I made an attempt to accomodate it.
I chose to use valpy_long in all cases because this simplifies porting
to Python 3, and because there didn't seem to be any harm.
Built and regtested on x86-64 Fedora 23.
2016-05-24 Tom Tromey <tom@tromey.com>
PR python/17386:
* python/py-value.c (value_object_as_number): Add
nb_inplace_floor_divide, nb_inplace_true_divide, nb_index.
2016-05-24 Tom Tromey <tom@tromey.com>
PR python/17386:
* gdb.python/py-value.exp (test_value_numeric_ops): Add tests that
use value as an index.
Python 2's PyNumberMethods has nb_inplace_divide, but Python 3 does
not. This patch adds it for Python 2.
This buglet didn't cause much fallout because the only non-NULL entry
in value_object_as_number after this is for valpy_divide; and the
missing slot caused it to slide up to nb_floor_divide (where
nb_true_divide was intended).
2016-05-24 Tom Tromey <tom@tromey.com>
* python/py-value.c (value_object_as_number): Add
nb_inplace_divide for Python 2.
PR python/17981 notes that gdb.breakpoints() returns None when there
are no breakpoints; whereas an empty list or tuple would be more in
keeping with Python and the documentation.
This patch fixes the bug by changing the no-breakpoint return to make
an empty tuple.
Built and regtested on x86-64 Fedora 23.
2016-05-23 Tom Tromey <tom@tromey.com>
PR python/17981:
* python/py-breakpoint.c (gdbpy_breakpoints): Return a new tuple
when there are no breakpoints.
2016-05-23 Tom Tromey <tom@tromey.com>
* python.texi (Basic Python): Document gdb.breakpoints return.
2016-05-23 Tom Tromey <tom@tromey.com>
PR python/17981:
* gdb.python/py-breakpoint.exp (test_bkpt_basic): Add test for
no-breakpoint case.
When GDB attaches to a process, it looks at the /proc/PID/task/ dir
for all clone threads of that process, and attaches to each of them.
Usually, if there is more than one clone thread, it means the program
is multi threaded and linked with pthreads. Thus when GDB soon after
attaching finds and loads a libthread_db matching the process, it'll
add a thread to the thread list for each of the initially found
lower-level LWPs.
If, however, GDB fails to find/load a matching libthread_db, nothing
is adding the LWPs to the thread list. And because of that, "detach"
hits an internal error:
(gdb) PASS: gdb.threads/clone-attach-detach.exp: fg attach 1: attach
info threads
Id Target Id Frame
* 1 LWP 6891 "clone-attach-de" 0x00007f87e5fd0790 in __nanosleep_nocancel () at ../sysdeps/unix/syscall-template.S:84
(gdb) FAIL: gdb.threads/clone-attach-detach.exp: fg attach 1: info threads shows two LWPs
detach
.../src/gdb/thread.c:1010: internal-error: is_executing: Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
FAIL: gdb.threads/clone-attach-detach.exp: fg attach 1: detach (GDB internal error)
From here:
...
#8 0x00000000007ba7cc in internal_error (file=0x98ea68 ".../src/gdb/thread.c", line=1010, fmt=0x98ea30 "%s: Assertion `%s' failed.")
at .../src/gdb/common/errors.c:55
#9 0x000000000064bb83 in is_executing (ptid=...) at .../src/gdb/thread.c:1010
#10 0x00000000004c23bb in get_pending_status (lp=0x12c5cc0, status=0x7fffffffdc0c) at .../src/gdb/linux-nat.c:1235
#11 0x00000000004c2738 in detach_callback (lp=0x12c5cc0, data=0x0) at .../src/gdb/linux-nat.c:1317
#12 0x00000000004c1a2a in iterate_over_lwps (filter=..., callback=0x4c2599 <detach_callback>, data=0x0) at .../src/gdb/linux-nat.c:899
#13 0x00000000004c295c in linux_nat_detach (ops=0xe7bd30, args=0x0, from_tty=1) at .../src/gdb/linux-nat.c:1358
#14 0x000000000068284d in delegate_detach (self=0xe7bd30, arg1=0x0, arg2=1) at .../src/gdb/target-delegates.c:34
#15 0x0000000000694141 in target_detach (args=0x0, from_tty=1) at .../src/gdb/target.c:2241
#16 0x0000000000630582 in detach_command (args=0x0, from_tty=1) at .../src/gdb/infcmd.c:2975
...
Tested on x86-64 Fedora 23. Also confirmed the test passes against
gdbserver with "maint set target-non-stop".
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (attach_proc_task_lwp_callback): Mark the lwp
resumed, and add the thread to GDB's thread list.
testsuite/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* gdb.threads/clone-attach-detach.c: New file.
* gdb.threads/clone-attach-detach.exp: New file.
Working on the fix for gdb/19828, I saw
gdb.threads/attach-many-short-lived-threads.exp fail once in an
unusual way. Unfortunately I didn't keep debug logs, but it's an
issue similar to what's been fixed in remote.c a while ago --
linux-nat.c was not fetching the pending status from the right place.
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (get_pending_status): If the thread reported the
event to the core and it's pending, use the pending status signal
number.
Hacking the gdb.threads/attach-many-short-lived-threads.exp test to
spawn thousands of threads instead of dozens, and running gdb under
perf, I saw that GDB was spending most of the time in find_lwp_pid:
- captured_main
- 93.61% catch_command_errors
- 87.41% attach_command
- 87.40% linux_nat_attach
- 87.40% linux_proc_attach_tgid_threads
- 82.38% attach_proc_task_lwp_callback
- 81.01% find_lwp_pid
5.30% ptid_get_lwp
+ 0.10% ptid_lwp_p
+ 0.64% add_thread
+ 0.26% set_running
+ 0.24% set_executing
0.12% ptid_get_lwp
+ 0.01% ptrace
+ 0.01% add_lwp
attach_proc_task_lwp_callback is called once for each LWP that we
attach to, found by listing the /proc/PID/task/ directory. In turn,
attach_proc_task_lwp_callback calls find_lwp_pid to check whether the
LWP we're about to try to attach to is already known. Since
find_lwp_pid does a linear walk over the whole LWP list, this becomes
quadratic. We do the /proc/PID/task/ listing until we get two
iterations in a row where we found no new threads. So the second and
following times we walk the /proc/PID/task/ dir, we're going to take
an even worse find_lwp_pid hit.
Fix this by adding a hash table keyed by LWP PID, for fast lookup.
The linked list embedded in the LWP structure itself is kept, and made
a double-linked list, so that removals from that list are O(1). An
earlier version of this patch got rid of this list altogether, but
that revealed hidden dependencies / assumptions on how the list is
sorted. For example, killing a process and then waiting for all the
LWPs status using iterate_over_lwps only works as is because the
leader LWP is always last in the list. So I thought it better to take
an incremental approach and make this patch concern itself _only_ with
the PID lookup optimization.
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (lwp_lwpid_htab): New htab.
(lwp_info_hash, lwp_lwpid_htab_eq, lwp_lwpid_htab_create)
(lwp_lwpid_htab_add_lwp): New functions.
(lwp_list): Tweak comment.
(lwp_list_add, lwp_list_remove, lwp_lwpid_htab_remove_pid): New
functions.
(purge_lwp_list): Rewrite, using htab_traverse_noresize.
(add_initial_lwp): Add lwp to htab too. Use lwp_list_add.
(delete_lwp): Use lwp_list_remove. Remove htab too.
(find_lwp_pid): Search in htab.
(_initialize_linux_nat): Call lwp_lwpid_htab_create.
* linux-nat.h (struct lwp_info) <prev>: New field.
Hacking the gdb.threads/attach-many-short-lived-threads.exp test to
spawn thousands of threads instead of dozens, I saw GDB having trouble
keeping up with threads being spawned too fast, when it tried to stop
them all. This was because while gdb is doing that, it updates the
thread list to make sure no new thread has sneaked in that might need
to be paused. It does this a few times until it sees no-new-threads
twice in a row. The thread listing update itself is not that
expensive, however, in the Linux backend, updating the threads list
calls linux_common_core_of_thread for each LWP to record on which core
each LWP was last seen running, which opens/reads/closes a /proc file
for each LWP which becomes expensive when you need to do it for
thousands of LWPs.
perf shows gdb in linux_common_core_of_thread 44% of the time, in the
stop_all_threads -> update_thread_list path in this use case.
This patch simply makes linux_common_core_of_thread avoid updating the
core the thread is bound to if the thread hasn't run since the last
time we updated that info. This makes linux_common_core_of_thread
disappear into the noise in the perf report.
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (linux_resume_one_lwp_throw): Clear the LWP's core
field.
(linux_nat_update_thread_list): Don't fetch the core if already
known.
... as it's _much_ faster.
Hacking the gdb.threads/attach-many-short-lived-threads.exp test to
spawn thousands of threads instead of dozens to stress and debug
timeout problems with gdb.threads/attach-many-short-lived-threads.exp,
I saw that GDB would spend several seconds just reading the
/proc/PID/smaps file, to determine the vDSO mapping range. GDB opens
and reads the whole file just once, and caches the result, but even
that is too slow. For example, with almost 8000 threads:
$ ls /proc/3518/task/ | wc -l
7906
reading the /proc/PID/smaps file grepping for "vdso" takes over 15
seconds :
$ time cat /proc/3518/smaps | grep vdso
7ffdbafee000-7ffdbaff0000 r-xp 00000000 00:00 0 [vdso]
real 0m15.371s
user 0m0.008s
sys 0m15.017s
Looking around the web for hints, I found a nice description of the
issue here:
http://backtrace.io/blog/blog/2014/11/12/large-thread-counts-and-slow-process-maps/
The problem is that /proc/PID/smaps wants to show the mappings as
being thread stack, and that has the kernel iterating over all threads
in the thread group, for each mapping.
The fix is to use the "map" file under /proc/PID/task/PID/ instead of
the /proc/PID/ one, as the former doesn't mark thread stacks for all
threads.
That alone drops the timing to the millisecond range on my machine:
$ time cat /proc/3518/task/3518/smaps | grep vdso
7ffdbafee000-7ffdbaff0000 r-xp 00000000 00:00 0 [vdso]
real 0m0.150s
user 0m0.009s
sys 0m0.084s
And since we only need the vdso mapping's address range, we can use
"maps" file instead of "smaps", and it's even cheaper:
/proc/PID/task/PID/maps :
$ time cat /proc/3518/task/3518/maps | grep vdso
7ffdbafee000-7ffdbaff0000 r-xp 00000000 00:00 0 [vdso]
real 0m0.027s
user 0m0.000s
sys 0m0.017s
gdb/ChangeLog:
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-tdep.c (find_mapping_size): Delete.
(linux_vsyscall_range_raw): Rewrite reading from
/proc/PID/task/PID/maps directly instead of using
gdbarch_find_memory_regions.
A following patch (fix for gdb/19828) makes linux-nat.c add threads to
GDB's thread list earlier in the "attach" sequence, and that causes a
surprising regression on
gdb.threads/attach-many-short-lived-threads.exp on my machine. The
extra "thread x exited" handling and traffic slows down that test
enough that GDB core has trouble keeping up with new threads that are
spawned while trying to stop existing ones.
I saw the exact same issue with remote/gdbserver a while ago and fixed
it in 65706a29ba (Remote thread create/exit events) so part of the
fix here is the exact same -- add support for thread created events to
gdb/linux-nat.c. infrun.c:stop_all_threads enables those events when
it tries to stop threads, which ensures that new threads never get a
chance to themselves start new threads, thus fixing the race.
gdb/
2016-05-24 Pedro Alves <palves@redhat.com>
PR gdb/19828
* linux-nat.c (report_thread_events): New global.
(linux_handle_extended_wait): Report
TARGET_WAITKIND_THREAD_CREATED if thread event reporting is
enabled.
(wait_lwp, linux_nat_filter_event): Report all thread exits if
thread event reporting is enabled. Remove comment.
(filter_exit_event): New function.
(linux_nat_wait_1): Use it.
(linux_nat_thread_events): New function.
(linux_nat_add_target): Install it as target_thread_events method.
Nowadays, GDB can't insert breakpoint on the return address of the
exception handler on ARM M-profile, because the address is a magic
one 0xfffffff9,
(gdb) bt
#0 CT32B1_IRQHandler () at ../src/timer.c:67
#1 <signal handler called>
#2 main () at ../src/timer.c:127
(gdb) info frame
Stack level 0, frame at 0x200ffa8:
pc = 0x4ec in CT32B1_IRQHandler (../src/timer.c:67); saved pc = 0xfffffff9
called by frame at 0x200ffc8
source language c.
Arglist at 0x200ffa0, args:
Locals at 0x200ffa0, Previous frame's sp is 0x200ffa8
Saved registers:
r7 at 0x200ffa0, lr at 0x200ffa4
(gdb) x/x 0xfffffff9
0xfffffff9: Cannot access memory at address 0xfffffff9
(gdb) finish
Run till exit from #0 CT32B1_IRQHandler () at ../src/timer.c:67
Ed:15: Target error from Set break/watch: Et:96: Pseudo-address (0xFFFFFFxx) for EXC_RETURN is invalid (GDB error?)
Warning:
Cannot insert hardware breakpoint 0.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
Command aborted.
even some debug probe can't set hardware breakpoint on the magic
address too,
(gdb) hbreak *0xfffffff9
Hardware assisted breakpoint 2 at 0xfffffff9
(gdb) c
Continuing.
Ed:15: Target error from Set break/watch: Et:96: Pseudo-address (0xFFFFFFxx) for EXC_RETURN is invalid (GDB error?)
Warning:
Cannot insert hardware breakpoint 2.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
Command aborted.
The problem described above is quite similar to PR 8841, in which GDB
can't set breakpoint on signal trampoline, which is mapped to a read-only
page by kernel. The rationale of this patch is to skip "unwritable"
frames when looking for caller frames in command "finish", and a new
gdbarch method code_of_frame_writable is added. This patch fixes
the problem on ARM cortex-m target, but it can be used to fix
PR 8841 too.
gdb:
2016-05-10 Yao Qi <yao.qi@arm.com>
* arch-utils.c (default_code_of_frame_writable): New function.
* arch-utils.h (default_code_of_frame_writable): Declare.
* arm-tdep.c (arm_code_of_frame_writable): New function.
(arm_gdbarch_init): Install gdbarch method
code_of_frame_writable if the target is M-profile.
* frame.c (skip_unwritable_frames): New function.
* frame.h (skip_unwritable_frames): Declare.
* gdbarch.sh (code_of_frame_writable): New.
* gdbarch.c, gdbarch.h: Re-generated.
* infcmd.c (finish_command): Call skip_unwritable_frames.
This fixes PR python/19438 and PR python/18393. Both bugs are about
invoking dir() on some Python object implemented by gdb, and getting a
crash.
The crash happens because the dictionary field of these objects was
not initialized. Apparently what happens is that this field can be
lazily initialized by Python when assigning to an attribute; and it
can also be handled ok when using dir() but without __dict__ defined;
but gdb defines __dict__ because this isn't supplied automatically by
Python.
The docs on this seem rather sparse, but this patch works ok.
An alternative might be to lazily create the dictionary in
gdb_py_generic_dict, but I went with this approach because it seemed
more straightforward.
Built and regtested on x86-64 Fedora 23.
2016-05-23 Tom Tromey <tom@tromey.com>
PR python/19438, PR python/18393:
* python/py-objfile.c (objfpy_initialize): Initialize self->dict.
* python/py-progspace.c (pspy_initialize): Initialize self->dict.
2016-05-23 Tom Tromey <tom@tromey.com>
PR python/19438, PR python/18393:
* gdb.python/py-progspace.exp: Add "dir" test.
* gdb.python/py-objfile.exp: Add "dir" test.
Native GDB looks up the function td_thr_validate from libthread_db.so
on Linux, but the value is never used. This commit removes this dead
code.
gdb/ChangeLog:
* nat/gdb_thread_db.h (td_thr_validate_ftype): Remove typedef.
* linux-thread-db.c (struct thread_db_info) <td_thr_validate_p>:
Remove field.
(try_thread_db_load_1): Remove td_thr_validate initialization.
GDB needs kinfo_getvmmap() on GNU/kFreeBSD systems same as on
pure FreeBSD. However on these systems the FreeBSD version of libutil
is renamed to libutil-freebsd.
2016-05-23 Jon Boden <jon@ubuntubsd.org>
* configure.ac: Search for libutil-freebsd as alternative to libutil.
* configure: Re-generated.
When you use a run control command (-exec-run, -exec-continue,
-exec-next, ...) with mi-async on, an extra (gdb) prompt is displayed:
-exec-continue
^running
*running,thread-id="all"
(gdb)
(gdb)
It doesn't seem to be a big problem for front-ends, since this behavior
started in gdb 7.9 and we haven't heard anything about that. However,
it caused me some trouble while writing a test for PR 20039 [1].
The problem comes from an extra (gdb) prompt that we write when running
in mi-async off mode to emulate a past buggy behavior. When executing a
run control command synchronously, previous gdbs always printed a prompt
right away, even though they are not ready to accept new MI commands
until the target stops. Only at this time should they display a prompt.
But to keep backwards compatibility apparently, we print it anyway.
Since commit 198297aaf, the condition that decides whether we should
print that "bogus" prompt or not has become true, even when running with
mi-async on. Since we already print a prompt at the end of the
asynchronous command execution, it results in two prompts for one
command.
The proposed fix is to call target_can_async_p instead of
target_is_async_p, to make the condition:
if (!target_can_async_p () || sync_execution)
... show prompt ...
That shows the prompt if we are emulating a synchronous command on top
of an asynchronous target (sync_execution) or if the target simply can't
run asynchronously (!target_can_async_p ()).
Note that this code is changed and this bug fixed by Pedro's separate
console series, but I think it would be nice to have it fixed in the
mean time.
I ran the gdb.mi directory of the testsuite with mi-async on and off, I
didn't see any regressions.
gdb/ChangeLog:
* mi/mi-main.c (mi_on_resume): Call target_can_async_p instead
of target_is_async_p.
[1] https://sourceware.org/ml/gdb-patches/2016-05/msg00075.html
When doing -exec-run on a freshly started GDB, the only target on the
target stack at the time the dummy one. When mi_async_p is called to
know whether the run should be async, it queries whether the current
target (dummy) supports async, and the answer is no. The fix is to make
the code query the target that will be used for the run, which is not
necessarily the current target.
No regressions in the gdb.mi directory using the unix, native-gdbserver
and native-extended-gdbserver boards. The test doesn't pass when
forcing maint set target-async off, obviously, since it makes mi-async
have no effect. It doesn't seem like other tests are checking for that
eventuality, so I didn't in the new test.
gdb/ChangeLog:
* mi/mi-main.c (run_one_inferior): Use run target to determine
whether to run async or not.
(mi_cmd_exec_run): Likewise.
gdb/testsuite/ChangeLog:
* gdb.mi/mi-async-run.exp: New file.
* gdb.mi/mi-async-run.c: New file.
This patch adds documentation for the new Rust support in gdb.
2016-05-17 Tom Tromey <tom@tromey.com>
* NEWS: Add Rust item.
2016-05-17 Tom Tromey <tom@tromey.com>
* gdb.texinfo (Supported Languages): Mention Rust. Update menu.
(Rust): New node.
For Rust value-printing, I wanted to use generic_val_print_array, but
I also wanted to control the starting and ending strings.
This patch adds new strings to generic_val_print_decorations, updates
generic_val_print_array to use them, and updates all the existing
instances of generic_val_print_decorations.
2016-05-17 Tom Tromey <tom@tromey.com>
* valprint.h (struct generic_val_print_array) <array_start,
array_end>: New fields.
* valprint.c (generic_val_print_array): Add "decorations"
parameter. Use "array_start", "array_end".
(generic_val_print) <TYPE_CODE_ARRAY>: Update.
* p-valprint.c (p_decorations): Update.
* m2-valprint.c (m2_decorations): Update.
* f-valprint.c (f_decorations): Update.
* c-valprint.c (c_decorations): Update.
I wanted to unit test the Rust lexer, so I added a simple unit testing
command to gdb.
The intent is that self tests will only be compiled into gdb in
development mode. In release mode they simply won't exist. So, this
exposes $development to C code as GDB_SELF_TEST.
In development mode, test functions are registered with the self test
module. A test function is just a function that does some checks, and
throws an exception on failure.
Then this adds a new "maint selftest" command which invokes the test
functions, and a new dejagnu test case that invokes it.
2016-05-17 Tom Tromey <tom@tromey.com>
* NEWS: Add "maint selftest" entry.
* selftest.h: New file.
* selftest.c: New file.
* maint.c: Include selftest.h.
(maintenance_selftest): New function.
(_initialize_maint_cmds): Add "maint selftest" command.
* configure.ac (GDB_SELF_TEST): Maybe define.
* config.in, configure: Rebuild.
* Makefile.in (SFILES): Add selftest.c.
(COMMON_OBS): Add selftest.o.
2016-05-17 Tom Tromey <tom@tromey.com>
* gdb.texinfo (Maintenance Commands): Document "maint selftest".
2016-05-17 Tom Tromey <tom@tromey.com>
* gdb.gdb/unittest.exp: New file.
print_subexp_standard and dump_subexp_body_standard did not handle
OP_F90_RANGE. Attempting to dump an expression using this opcode
would fail.
This patch adds support for this opcode to these functions.
2016-05-17 Tom Tromey <tom@tromey.com>
* expprint.c: Include f-lang.h.
(print_subexp_standard, dump_subexp_body_standard): Handle
OP_F90_RANGE.
gdb's Makefile.in does not currently scan .y files to add global
initializers from these files to init.c. However, at least ada-exp.y
tries to use this feature.
This patch fixes the problem.
2016-05-17 Tom Tromey <tom@tromey.com>
* Makefile.in (init.c): Search .y files for initialization
functions.
gdb/ChangeLog:
* dwarf2loc.c (dwarf2_find_location_expression): For DWO files still
add base_offset.
gdb/testsuite/ChangeLog:
* lib/dwarf.exp (build_executable_from_fission_assembler): Pass
$options when building executable.
* gdb.dwarf2/fission-loclists-pie.c: New file.
* gdb.dwarf2/fission-loclists-pie.exp: New file.
2016-05-10 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* elf32-arm.c (elf32_arm_size_stubs): Use new macros
ARM_GET_SYM_BRANCH_TYPE and ARM_SET_SYM_BRANCH_TYPE to respectively get
and set branch type of a symbol.
(bfd_elf32_arm_process_before_allocation): Likewise.
(elf32_arm_relocate_section): Likewise and fix identation along the
way.
(allocate_dynrelocs_for_symbol): Likewise.
(elf32_arm_finish_dynamic_symbol): Likewise.
(elf32_arm_swap_symbol_in): Likewise.
(elf32_arm_swap_symbol_out): Likewise.
gas/
* config/tc-arm.c (arm_adjust_symtab): Use ARM_SET_SYM_BRANCH_TYPE to
set branch type of a symbol.
gdb/
* arm-tdep.c (arm_elf_make_msymbol_special): Use
ARM_GET_SYM_BRANCH_TYPE to get branch type of a symbol.
include/
* arm.h (enum arm_st_branch_type): Add new ST_BRANCH_ENUM_SIZE
enumerator.
(NUM_ENUM_ARM_ST_BRANCH_TYPE_BITS): New macro.
(ENUM_ARM_ST_BRANCH_TYPE_BITMASK): Likewise.
(ARM_SYM_BRANCH_TYPE): Replace by ...
(ARM_GET_SYM_BRANCH_TYPE): This and ...
(ARM_SET_SYM_BRANCH_TYPE): This in two versions depending on whether
BFD_ASSERT is defined or not.
ld/
* emultempl/armelf.em (gld${EMULATION_NAME}_finish): Use
ARM_GET_SYM_BRANCH_TYPE to get branch type of a symbol.
opcodes/
* arm-dis.c (get_sym_code_type): Use ARM_GET_SYM_BRANCH_TYPE to get
branch type of a symbol.
(print_insn): Likewise.
ChangeLog:
* spu-linux-nat.c (spu_bfd_iovec_pread): Add pointer cast for C++.
(spu_bfd_open): Likewise.
gdbserver/ChangeLog:
* spu-low.c (fetch_ppc_register): Cast PowerPC-Linux-specific value
used as first ptrace argument to PTRACE_TYPE_ARG1 for C++.
(fetch_ppc_memory_1, store_ppc_memory_1): Likewise.
Nowadays, read_memory may throw NOT_AVAILABLE_ERROR (it is done by
patch http://sourceware.org/ml/gdb-patches/2013-08/msg00625.html)
however, read_stack and read_code still throws MEMORY_ERROR only. This
causes PR 19947, that is prologue unwinder is unable unwind because
code memory isn't available, but MEMORY_ERROR is thrown, while unwinder
catches NOT_AVAILABLE_ERROR.
#0 memory_error (err=err@entry=TARGET_XFER_E_IO, memaddr=memaddr@entry=140737349781158) at /home/yao/SourceCode/gnu/gdb/git/gdb/corefile.c:217
#1 0x000000000065f5ba in read_code (memaddr=memaddr@entry=140737349781158, myaddr=myaddr@entry=0x7fffffffd7b0 "\340\023<\001", len=len@entry=1)
at /home/yao/SourceCode/gnu/gdb/git/gdb/corefile.c:288
#2 0x000000000065f7b5 in read_code_unsigned_integer (memaddr=memaddr@entry=140737349781158, len=len@entry=1, byte_order=byte_order@entry=BFD_ENDIAN_LITTLE)
at /home/yao/SourceCode/gnu/gdb/git/gdb/corefile.c:363
#3 0x00000000004717e0 in amd64_analyze_prologue (gdbarch=gdbarch@entry=0x13c13e0, pc=140737349781158, current_pc=140737349781165, cache=cache@entry=0xda0cb0)
at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2267
#4 0x0000000000471f6d in amd64_frame_cache_1 (cache=0xda0cb0, this_frame=0xda0bf0) at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2437
#5 amd64_frame_cache (this_frame=0xda0bf0, this_cache=<optimised out>) at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2508
#6 0x000000000047214d in amd64_frame_this_id (this_frame=<optimised out>, this_cache=<optimised out>, this_id=0xda0c50)
at /home/yao/SourceCode/gnu/gdb/git/gdb/amd64-tdep.c:2541
#7 0x00000000006b94c4 in compute_frame_id (fi=0xda0bf0) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:481
#8 get_prev_frame_if_no_cycle (this_frame=this_frame@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1809
#9 0x00000000006bb6c9 in get_prev_frame_always_1 (this_frame=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1983
#10 get_prev_frame_always (this_frame=this_frame@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1999
#11 0x00000000006bbe11 in get_prev_frame (this_frame=this_frame@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:2241
#12 0x00000000006bc13c in unwind_to_current_frame (ui_out=<optimised out>, args=args@entry=0xda0b20) at /home/yao/SourceCode/gnu/gdb/git/gdb/frame.c:1485
The fix is to let read_stack and read_code throw NOT_AVAILABLE_ERROR too,
in order to align with read_memory.
gdb:
2016-05-04 Yao Qi <yao.qi@linaro.org>
PR gdb/19947
* corefile.c (read_memory): Rename it to ...
(read_memory_object): ... it. Add parameter object.
(read_memory): Call read_memory_object.
(read_stack): Likewise.
(read_code): Likewise.
PR symtab/19914
* dwarf2read.c (open_and_init_dwp_file): Look at backlink if objfile
is separate debug file.
testsuite/
* gdb.dwarf2/dwp-sepdebug.c: New file.
* gdb.dwarf2/dwp-sepdebug.exp: New file.
Valgrind shows:
==26964== Invalid read of size 1
==26964== at 0x6E14100: __GI_strcmp (strcmp.S:180)
==26964== by 0x6DB55AA: setlocale (setlocale.c:238)
==26964== by 0x4E0455: _initialize_python() (python.c:1731)
==26964== by 0x786731: initialize_all_files() (init.c:319)
==26964== by 0x72EF0A: gdb_init(char*) (top.c:1929)
==26964== by 0x60BCAC: captured_main(void*) (main.c:863)
==26964== by 0x606AD5: catch_errors(int (*)(void*), void*, char*, return_mask) (exceptions.c:234)
==26964== by 0x60C608: gdb_main(captured_main_args*) (main.c:1165)
==26964== by 0x40CAEC: main (gdb.c:32)
==26964== Address 0x81d30a0 is 0 bytes inside a block of size 181 free'd
==26964== at 0x4C29CF0: free (vg_replace_malloc.c:530)
==26964== by 0x6DB5B65: setname (setlocale.c:201)
==26964== by 0x6DB5B65: setlocale (setlocale.c:388)
==26964== by 0x4E037F: _initialize_python() (python.c:1712)
==26964== by 0x786731: initialize_all_files() (init.c:319)
==26964== by 0x72EF0A: gdb_init(char*) (top.c:1929)
==26964== by 0x60BCAC: captured_main(void*) (main.c:863)
==26964== by 0x606AD5: catch_errors(int (*)(void*), void*, char*, return_mask) (exceptions.c:234)
==26964== by 0x60C608: gdb_main(captured_main_args*) (main.c:1165)
==26964== by 0x40CAEC: main (gdb.c:32)
The problem is doing this:
oldloc = setlocale (LC_ALL, NULL);
setlocale (LC_ALL, "");
...
setlocale (LC_ALL, oldloc);
I.e., the second setlocale call frees 'oldloc'.
From http://pubs.opengroup.org/onlinepubs/9699919799/functions/setlocale.html :
"The returned string pointer might be invalidated or the string
content might be overwritten by a subsequent call to setlocale()."
gdb/ChangeLog:
2016-05-03 Pedro Alves <palves@redhat.com>
PR python/20037
* python/python.c (_initialize_python) [IS_PY3K]: xstrdup/xfree
oldloc.
This makes no sense -- strlen doesn't really ever fail with -1.
gdb/ChangeLog:
2016-05-03 Pedro Alves <palves@redhat.com>
* python/python.c (_initialize_python) [IS_PY3K]: Remove dead
code.
GDB's use of --dynamic-list to only export the proc-service symbols is
broken due to Python's "python-config --ldflags" saying we should link
with -export-dynamic, causing us to export _all_ extern symbols
anyway. On Fedora 23:
$ python-config --ldflags
-lpython2.7 -lpthread -ldl -lutil -lm -Xlinker -export-dynamic
$ python3.4-config --ldflags
-L/usr/lib64 -lpython3.4m -lpthread -ldl -lutil -lm -Xlinker -export-dynamic
Having GDB export all its symbols leads to issues such as PR gdb/16818
(GDB crashes when using name for target remote hostname:port), where a
GDB symbol unintentionally preempts a symbol in one of the NSS modules
glibc loads into the process. NSS modules should not define symbols
outside the implementation namespace or the relevant standards, but,
alas, that's a longstanding and hard to fix issue. See libc-alpha
discussion at:
[symbol name space issues with NSS modules]
https://sourceware.org/ml/libc-alpha/2016-04/msg00130.html
Python should instead be either using GCC's symbol visibility feature
or -Wl,--dynamic-list as well, to only export Python API symbols, but,
it doesn't. There are bugs open upstream for that:
[Use -Wl,--dynamic-list=x.list, not -Xlinker -export-dynamic]
http://bugs.python.org/issue10112
[Use GCC visibility attrs in PyAPI_*]
http://bugs.python.org/issue11410
But that's taking a long while to resolve.
I thought of working around this Python issue by making GDB build with
-fvisibility=hidden, as Jan suggests in Python issue 10112, as then
Python's "-Xlinker -export-dynamic" has no effect. However, that
would need to be done in the whole source tree (bfd, libiberty, etc.),
and I think that would break GCC plugins, as I believe those have
access to all of GCCs symbols, by "design". So we'd need a new
configure switch, or have the libraries in the tree detect which of
GCC or GDB is being built, but that doesn't work, because the answer
can be "both" with combined builds...
So this patch instead works around Python's bug, by simply sed'ing
away "-Xlinker -export-dynamic" from the result of python-config.py
--ldflags, making -Wl,--dynamic-list work again as it used to. It's
ugly, but so is the bug...
Note that if -Wl,--dynamic-list doesn't work, we always link with
-rdynamic, so static Python should still work.
Tested on F23 with --python=python (Python 2.7) and
--python=python3.4.
gdb/ChangeLog:y
2016-05-03 Pedro Alves <palves@redhat.com>
* configure.ac (PYTHON_LIBS): Sed away "-Xlinker -export-dynamic".
* configure: Regenerate.
The -Wl,--dynamic-list test is currently broken on Fedora 23, when you
configure with --with-python=python3.4. We see:
configure:13741: checking for the dynamic export flag
configure:13796: gcc -o conftest -g3 -O0 -fno-strict-aliasing -DNDEBUG -fwrapv -Wl,--dynamic-list=/home/pedro/gdb/mygit/src/gdb/proc-service.list conftest.c -ldl -lncurses -lm -ldl -lpthread -ldl -lutil -lm -lpython3.4m -Xlinker -export-dynamic >&5
conftest.c:182:30: fatal error: python3.4/Python.h: No such file or directory
compilation terminated.
configure:13796: $? = 1
The correct -I path is in PYTHON_CPPFLAGS:
PYTHON_CPPFLAGS='-I/usr/include/python3.4m -I/usr/include/python3.4m'
(Other Python-related tests in the file are already doing this.)
gdb/ChangeLog:
2016-05-03 Pedro Alves <palves@redhat.com>
* configure.ac (checking for the dynamic export flag): Add
$PYTHON_CPPFLAGS to CPPFLAGS.
* configure: Regenerate.
* windows-nat.c (_initialize_check_for_gdb_ini): Fix off-by-one
error in allocation of space for "$HOME/.gdbinit" string. This
caused GDB to abort on startup whenever a '~/gdb.ini' file was
actually found, because xsnprintf would hit an assertion
violation.
Just like completion doesn't show deprecated commands, I think that help
should not list them, so that we don't incite users to use them.
gdb/ChangeLog:
* cli/cli-decode.c (help_cmd_list): Do not list commands that
are deprecated.
With current FSF GDB HEAD and old FSF gdbserver I expected I could do:
gdb -ex 'file target:/root/redhat/threadit' -ex 'target remote :1234'
(supplying that unsupported qXfer:exec-file:read by "file")
But that does not work because:
Sending packet: $vFile:setfs:0#bf...Packet received: OK
Packet vFile:setfs (hostio-setfs) is supported
...
Sending packet: $vFile:setfs:104#24...Packet received: OK
"target:/root/redhat/threadit": could not open as an executable file: Invalid argument
GDB documentation says:
The valid responses to Host I/O packets are:
An empty response indicates that this operation is not recognized.
This "empty response" vs. "OK" was a bug in gdbserver < 7.7. It was fixed by:
commit e7f0d979dd
Author: Yao Qi <yao@codesourcery.com>
Date: Tue Dec 10 21:59:20 2013 +0800
Fix a bug in matching notifications.
Message-ID: <1386684626-11415-1-git-send-email-yao@codesourcery.com>
https://sourceware.org/ml/gdb-patches/2013-12/msg00373.html
2013-12-10 Yao Qi <yao@codesourcery.com>
* notif.c (handle_notif_ack): Return 0 if no notification
matches.
with unpatched old FSF gdbserver and patched FSF GDB HEAD:
gdb -ex 'file target:/root/redhat/threadit' -ex 'target remote :1234'
Sending packet: $vFile:setfs:0#bf...Packet received: OK
Packet vFile:setfs (hostio-setfs) is NOT supported
...
(gdb) info sharedlibrary
From To Syms Read Shared Object Library
0x00007ffff7ddbae0 0x00007ffff7df627a Yes (*) target:/lib64/ld-linux-x86-64.so.2
0x00007ffff7bc48a0 0x00007ffff7bcf514 Yes (*) target:/lib64/libpthread.so.0
gdb/ChangeLog
2016-04-26 Jan Kratochvil <jan.kratochvil@redhat.com>
* remote.c (remote_start_remote): Detect PACKET_vFile_setfs.support.
Currently c_value_print will turn struct reference values into pointers before
doing a set of RTTI checks. This was introduced as a fix to PR c++/15401.
If there's RTTI the pointer will be adjusted and converted back to a reference.
However, if there's no RTTI the value will still be treated as a pointer during
the remainder of the function.
This patch moves the conversion down so that it's always performed when needed.
Notice this currently has not user-visible effects, so can be seen as a small
code cleanup. However, it'll be necessary for the bug-fix for handling
synthetic C++ references. It causes no testsuite regressions.
gdb/ChangeLog:
2016-04-26 Martin Galvan <martin.galvan@tallertechnologies.com>
* c-valprint.c (c_value_print): Always convert val back to reference
type if we converted it to a pointer type.
In some babeltrace versions before 1.2.0, the header file iterator.h
declares the enum values `BT_SEEK_*' within the struct declaration of
bt_iter_pos. The enum values are supposed to be globally-scoped, which
works for C, but not for C++. Later babeltrace versions declare the
enum outside the struct:
https://lists.lttng.org/pipermail/lttng-dev/2013-September/021411.html
Now that GDB is compiled with C++, the GDB build fails on a system with
an affected babeltrace version: the compiler complains about a missing
declaration of BT_SEEK_BEGIN in ctf.c.
This patch enhances the configure check to recognize such babeltrace
versions as unusable for GDB.
gdb/ChangeLog:
* configure.ac: Enhance configure check for babeltrace to reject
non-C++-enabled versions.
* configure: Regenerate.
Instead of pre-computing indices into a fortran array re-use
the value_* interfaces to subscript a fortran array.
The benefit of using the new interface is that it takes care of
dynamic types and resolve them when needed.
This fixes issues when printing structures with dynamic arrays from toplevel.
Before:
(gdb) p twov
$1 = ( (( ( 6352320, 0, -66, -1, 267) ( 343476, 1, -15, 1, 0) ( 5, 0, 5, 0, 1) ...
After:
(gdb) p twov
$1 = ( (( ( 1, 1, 1, 1, 1) ( 1, 1, 321, 1, 1) ( 1, 1, 1, 1, 1) ...
2016-04-26 Sanimir Agovic <sanimir.agovic@intel.com>
Keven Boell <keven.boell@intel.com>
Bernhard Heckel <bernhard.heckel@intel.com>
gdb/Changelog:
* f-valprint.c (f77_create_arrayprint_offset_tbl): Remove
function.
(F77_DIM_SIZE, F77_DIM_OFFSET): Remove macro.
(f77_print_array_1): Use value_subscript to subscript a
value array.
(f77_print_array): Remove call to f77_create_arrayprint_offset_tbl.
(f_val_print): Use value_field to construct a field value.
gdb/testsuite/Changelog:
* vla-type.exp: Print structure from toplevel.
Resolve type of an array's element to be printed in case it is dynamic.
Otherwise we don't use the correct boundaries nor the right location.
Before:
ptype fivearr(1)
type = Type five
Type one
integer(kind=4) :: ivla(34196784:34196832,34197072:34197120,34197360:34197408)
End Type one :: tone
End Type five
After:
ptype fivearr(1)
type = Type five
Type one
integer(kind=4) :: ivla(2,4,6)
End Type one :: tone
End Type five
2016-04-26 Bernhard Heckel <bernhard.heckel@intel.com>
gdb/Changelog:
* valarith.c (value_address): Resolve dynamic types.
gdb/testsuite/Changelog:
* gdb.fortran/vla-type.f90: Add test for static and dynamic arrays
of dynamic types.
* gdb.fortran/vla-type.exp: Add test for static and dynamic arrays
of dynamic types.
Fortran supports dynamic types for which bounds, size and location
can vary during their lifetime. As a result of the dynamic
behaviour, they have to be resolved at every query.
This patch will resolve the type of a structure field when it
is dynamic.
2016-04-26 Bernhard Heckel <bernhard.heckel@intel.com>
2016-04-26 Keven Boell <keven.boell@intel.com>
Before:
(gdb) print threev%ivla(1)
Cannot access memory at address 0x3
(gdb) print threev%ivla(5)
no such vector element
After:
(gdb) print threev%ivla(1)
$9 = 1
(gdb) print threev%ivla(5)
$10 = 42
gdb/Changelog:
* NEWS: Add new supported features for fortran.
* gdbtypes.c (remove_dyn_prop): New.
(resolve_dynamic_struct): Keep type length for fortran structs.
* gdbtypes.h: Forward declaration of new function.
* value.c (value_address): Return dynamic resolved location of a value.
(set_value_component_location): Adjust the value address
for single value prints.
(value_primitive_field): Support value types with a dynamic location.
(set_internalvar): Remove dynamic location property of
internal variables.
gdb/testsuite/Changelog:
* gdb.fortran/vla-type.f90: New file.
* gdb.fortran/vla-type.exp: New file.
When GDBserver inserts a breakpoint, it looks for raw breakpoint, if
the raw breakpoint is found, increase its refcount, and return. This
doesn't work when it steps over a breakpoint using software single
step and the underneath instruction of breakpoint is branch to self.
When stepping over a breakpoint on ADDR using software single step,
GDBserver uninsert the breakpoint, so the corresponding raw breakpoint
RAW's 'inserted' flag is zero. Then, GDBserver insert single step
breakpoint at the same address ADDR because the instruction is branch
to self, the same raw brekapoint RAW is found, and increase the
refcount. However, the raw breakpoint is not inserted, and the
program won't stop.
gdb/gdbserver:
2016-04-25 Pedro Alves <palves@redhat.com>
Yao Qi <yao.qi@linaro.org>
* mem-break.c (set_raw_breakpoint_at): Create a raw breakpoint
object. Insert it if it is not inserted yet. Increase the
refcount and link it into the proc's raw breakpoint list.
GDB doesn't insert software single step breakpoint if the instruction
branches to itself, so that the program can't stop after command "si".
(gdb) b 32
Breakpoint 2 at 0x8680: file git/gdb/testsuite/gdb.base/branch-to-self.c, line 32.
(gdb) c
Continuing.
Breakpoint 2, main () at gdb/git/gdb/testsuite/gdb.base/branch-to-self.c:32
32 asm (".Lhere: " BRANCH_INSN " .Lhere"); /* loop-line */
(gdb) si
infrun: clear_proceed_status_thread (Thread 3991.3991)
infrun: proceed (addr=0xffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: step-over queue now empty
infrun: resuming [Thread 3991.3991] for step-over
infrun: skipping breakpoint: stepping past insn at: 0x8680
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Sending packet: $Z0,8678,4#f3...Packet received: OK
infrun: skipping breakpoint: stepping past insn at: 0x8680
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Sending packet: $Z0,b6fe86c8,4#82...Packet received: OK
infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [Thread 3991.3991] at 0x868
breakpoint.c:should_be_inserted thinks the breakpoint shouldn't be
inserted, which is wrong. This patch restrict the condition that
only skip the non-single-step breakpoints if they are inserted at
the place we are stepping over, however we don't want to skip
single-step breakpoint if its thread is the thread we are stepping
over, so in this patch, I add a thread num in 'struct step_over_info'
to record the thread we're stepping over.
gdb:
2016-04-25 Yao Qi <yao.qi@linaro.org>
* breakpoint.c (should_be_inserted): Return 0 if the location's
owner is not single step breakpoint or single step breakpoint's
thread isn't the thread which is stepping past a breakpoint.
* gdbarch.sh (software_single_step): Update comments.
* gdbarch.h: Regenerated.
* infrun.c (struct step_over_info) <thread>: New field.
(set_step_over_info): New argument 'thread'. Callers updated.
(clear_step_over_info): Set field thread to -1.
(thread_is_stepping_over_breakpoint): New function.
* infrun.h (thread_is_stepping_over_breakpoint): Declaration.
gdb/ChangeLog
* ppc-linux-nat.c (ppc_linux_read_description): Use PPC_FEATURE_HAS_VSX
and PPC_FEATURE_HAS_ALTIVEC to check if such features are available.
Before this patch
https://sourceware.org/ml/gdb-patches/2014-02/msg00709.html
read_value_memory checks parameter 'stack', and call read_stack or
read_memory respectively. However, 'stack' is not checked and
TARGET_OBJECT_MEMORY is always used in target_xfer_partial, which is
a mistake in the patch above.
This patch checks parameter 'stack', and choose TARGET_OBJECT_MEMORY
or TARGET_OBJECT_STACK_MEMORY accordingly.
gdb:
2016-04-22 Yao Qi <yao.qi@linaro.org>
* valops.c (read_value_memory): New local variable 'stack'.
Set it to either TARGET_OBJECT_STACK_MEMORY or
TARGET_OBJECT_MEMORY.
This factors out all the yy-variables remapping to a single file,
instead of each parser having to do the same, with different prefixes.
With this, a parser just needs to define the prefix they want and
include yy-remap.h, which does the dirty job.
Note this renames the c_error, ada_error, etc. functions. Writing the
remapping pattern as:
#define yyerror GDB_YY_REMAP (error)
instead of:
#define yyerror GDB_YY_REMAP (yyerror)
would have avoided the renaming. However, that would be problematic
if we have a macro 'foo' in scope, when we write:
#define yyfoo GDB_YY_REMAP (foo)
as that would expand 'foo'.
The c_yyerror etc. naming end ups indicating that this is a yacc
related function more clearly, so feels like a good change, anyway.
gdb/ChangeLog:
2016-04-22 Pedro Alves <palves@redhat.com>
* ada-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* ada-lang.c (ada_language_defn): Adjust.
* ada-lang.h (ada_error): Rename to ...
(ada_yyerror): ... this.
* c-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Adjust.
* c-lang.h (c_error): Rename to ...
(c_yyerror): ... this.
* d-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* d-lang.c (d_language_defn): Adjust.
* d-lang.h (d_error): Rename to ...
(d_yyerror): ... this.
* f-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* f-lang.c (f_language_defn): Adjust.
* f-lang.h (f_error): Rename to ...
(f_yyerror): ... this.
* go-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* go-lang.c (go_language_defn): Adjust.
* go-lang.h (go_error): Rename to ...
(go_yyerror): ... this.
* jv-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* jv-lang.c (java_language_defn): Adjust.
* jv-lang.h (java_error): Rename to ...
(java_yyerror): ... this.
* m2-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* m2-lang.c (m2_language_defn): Adjust.
* m2-lang.h (m2_error): Rename to ...
(m2_yyerror): ... this.
* objc-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* objc-lang.c (objc_language_defn): Adjust.
* opencl-lang.c (opencl_language_defn): Adjust.
* p-exp.y: Remove all yy symbol remappings.
(GDB_YY_REMAP_PREFIX): Define.
Include "yy-remap.h".
* p-lang.c (pascal_language_defn): Adjust.
* p-lang.h (pascal_error): Rename to ...
(pascal_yyerror): ... this.
* yy-remap.h: New file.
The exceptions-across-readline issue was fixed by the previous commit.
Let's try this again.
gdb/ChangeLog:
2016-04-22 Pedro Alves <palves@redhat.com>
* common/common-exceptions.h (GDB_XCPT_TRY): Remove mention of
the foreign frames issue.
[__cplusplus] (GDB_XCPT): Define as GDB_XCPT_TRY.
If we map GDB'S TRY/CATCH macros to C++ try/catch, GDB breaks on
systems where readline isn't built with exceptions support. The
problem is that readline calls into GDB through the callback
interface, and if GDB's callback throws a C++ exception/error, the
system unwinder won't manage to unwind past the readline frame, and
ends up calling std::terminate(), which aborts the process:
(gdb) whatever-command-that-causes-an-error
terminate called after throwing an instance of 'gdb_exception_RETURN_MASK_ERROR'
Aborted
$
This went unnoticed for so long because:
- the x86-64 ABI requires -fasynchronous-unwind-tables, making it
possible for exceptions to cross readline with no special handling.
But e.g., on ARM or AIX, unless you build readline with
-fexceptions, you trip on the problem.
- TRY/CATCH was mapped to setjmp/longjmp, even in C++ mode, until
quite recently.
The fix is to catch and save any GDB exception that is thrown inside
the GDB readline callback, and then once the callback returns back to
the GDB code that called into readline in the first place, rethrow the
saved GDB exception.
This is similar in spirit to how we catch/map GDB exceptions at the
GDB/Python and GDB/Guile API boundaries.
The next question is then: if we intercept all exceptions within GDB's
readline callback, should we simply return normally to readline? The
callback prototype has no way to signal an error back to readline (*).
The answer is no -- if we return normally, we'll be returning to a
loop inside rl_callback_read_char that continues processing pending
input, calling into GDB again, redisplaying the prompt, etc. Thus if
we want to error out of rl_callback_read_char, we need to long jump
across it, just like we always did before TRY/CATCH were ever mapped
to C++ exceptions.
My first approach built a specialized API to handle this, with a
couple macros to hide the setjmp/longjmp and the struct gdb_exception
saving/rethrowing.
However, I realized that we need to:
- Handle multiple active rl_callback_read_char invocations. If,
while processing input something triggers a secondary prompt, we
end up in a nested rl_callback_read_char call, through
gdb_readline_wrapper.
- Propagate a struct gdb_exception along with the longjmp.
... and that this is exactly what the setjmp/longjmp-based TRY/CATCH
does.
So the fix makes the setjmp/longjmp TRY/CATCH always available under
new TRY_SJLJ/CATCH_SJLJ aliases, even when TRY/CATCH is mapped to C++
try/catch, and then uses TRY_SJLJ/CATCH_SJLJ to propagate GDB
exceptions across the readline callback.
This turns out to be a much better looking fix than my bespoke API
attempt, even. We'll probably be able to simplify TRY_SJLJ/CATCH_SJLJ
when we finally get rid of TRY/CATCH all over the tree, but until
then, this reuse seems quite nice for avoiding a second parallel
setjmp/longjmp mechanism.
(*) - maybe we could propose a readline API change, but we still need
to handle current readline, anyway.
gdb/ChangeLog:
2016-04-22 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (enum catcher_state, struct catcher)
(current_catcher): Define in C++ mode too.
(exceptions_state_mc_catch): Call throw_exception_sjlj instead of
throw_exception.
(throw_exception_sjlj, throw_exception_cxx): New functions,
factored out from throw_exception.
(throw_exception): Reimplement.
* common/common-exceptions.h (exceptions_state_mc_init)
(exceptions_state_mc_action_iter)
(exceptions_state_mc_action_iter_1, exceptions_state_mc_catch):
Declare in C++ mode too.
(TRY): Rename to ...
(TRY_SJLJ): ... this.
(CATCH): Rename to ...
(CATCH_SJLJ): ... this.
(END_CATCH): Rename to ...
(END_CATCH_SJLJ): ... this.
[GDB_XCPT == GDB_XCPT_SJMP] (TRY, CATCH, END_CATCH): Map to SJLJ
equivalents.
(throw_exception): Update comments.
(throw_exception_sjlj): Declare.
* event-top.c (gdb_rl_callback_read_char_wrapper): Extend intro
comment. Wrap body in TRY_SJLJ/CATCH_SJLJ and rethrow any
intercepted exception.
(gdb_rl_callback_handler): New function.
(gdb_rl_callback_handler_install): Always install
gdb_rl_callback_handler as readline callback.
Use the "gdb_rl_" prefix like other gdb readline function wrappers to
make it clear this is a gdb function, not a readline function.
gdb/ChangeLog:
2016-04-22 Pedro Alves <palves@redhat.com>
* event-top.c (rl_callback_read_char_wrapper): Rename to ...
(gdb_rl_callback_read_char_wrapper): ... this.
(change_line_handler, gdb_setup_readline): Adjust.
Bits 20 ~ 23 of CPSR are reserved (RAZ, read as zero), but they are not
zero if the arm program runs on aarch64-linux. AArch64 tracer gets PSTATE
from arm 32-bit tracee as CPSR, but bits 20 ~ 23 are used in PSTATE. I
think kernel should clear these bits when it is read through ptrace, but
the fix in user space is still needed.
This patch fixes these two fails,
-FAIL: gdb.reverse/insn-reverse.exp: ext_reg_push_pop: compare registers on insn 0:vldr d7, [r11, #-12]
-FAIL: gdb.reverse/insn-reverse.exp: ext_reg_push_pop: compare registers on insn 0:vldr d7, [r7]
gdb:
2016-04-22 Yao Qi <yao.qi@linaro.org>
* aarch32-linux-nat.c (aarch32_gp_regcache_supply): Clear CPSR
bits 20 to 23.
gdb/gdbserver:
2016-04-22 Yao Qi <yao.qi@linaro.org>
* linux-aarch32-low.c (arm_store_gregset): Clear CPSR bits 20
to 23.
Set the number of registers for non-XML-described Linux targets to 90,
reverting a change made here with the addition of DSP register support:
commit 1faeff088b
Author: Maciej W. Rozycki <macro@linux-mips.org>
Date: Thu Mar 1 22:19:48 2012 +0000
and fixing a regression introduced for legacy `gdbserver' targets
causing a "Remote 'g' packet reply is too long" error message where the
amount of register data received with a `g' packet (90) exceeds the
maximum number of registers expected (79).
Update the setting for XML-described targets, reflecting the actual
number of registers which have been assigned numbers, matching the:
gdb_assert (gdbarch_num_regs (gdbarch) <= MIPS_RESTART_REGNUM);
requirement in `mips_linux_init_abi'.
gdb/
* mips-tdep.c (mips_gdbarch_init): For GDB_OSABI_LINUX set
`num_regs' to 90 rather than 79. Where a target description is
present adjust the setting appropriately.
We don't currently handle the case of gdb's readline callback throwing
gdb C++ exceptions across a readline that wasn't built with
-fexceptions. The end result is:
(gdb) whatever-command-that-causes-an-error
terminate called after throwing an instance of 'gdb_exception_RETURN_MASK_ERROR'
Aborted
$
Until that is fixed, revert back to sjlj-based exceptions again.
gdb/ChangeLog:
2016-04-21 Pedro Alves <palves@redhat.com>
* common/common-exceptions.h (GDB_XCPT_TRY): Add comment.
(GDB_XCPT): Always define as GDB_XCPT_SJMP.
We currently get:
../../src/gdb/aix-thread.c: In function 'int pdc_read_data(pthdb_user_t, void*, pthdb_addr_t, size_t)':
../../src/gdb/aix-thread.c:465:46: error: invalid conversion from 'void*' to 'gdb_byte* {aka unsigned char*}' [-fpermissive]
status = target_read_memory (addr, buf, len);
^
../../src/gdb/aix-thread.c: In function 'void aix_thread_resume(target_ops*, ptid_t, int, gdb_signal)':
../../src/gdb/aix-thread.c:1010:46: error: invalid conversion from 'void*' to 'int*' [-fpermissive]
gdb_signal_to_host (sig), (void *) tid);
^
../../src/gdb/aix-thread.c:243:1: error: initializing argument 5 of 'int ptrace64aix(int, int, long long int, int, int*)' [-fpermissive]
ptrace64aix (int req, int id, long long addr, int data, int *buf)
../../src/gdb/rs6000-nat.c: In function 'gdb_byte* rs6000_ptrace_ldinfo(ptid_t)':
../../src/gdb/rs6000-nat.c:596:36: error: invalid conversion from 'void*' to 'gdb_byte* {aka unsigned char*}' [-fpermissive]
gdb_byte *ldi = xmalloc (ldi_size);
^
../../src/gdb/rs6000-nat.c:615:36: error: invalid conversion from 'void*' to 'gdb_byte* {aka unsigned char*}' [-fpermissive]
ldi = xrealloc (ldi, ldi_size);
^
(and more instances of the same).
gdb/ChangeLog:
2016-04-21 Pedro Alves <palves@redhat.com>
* aix-thread.c (pdc_read_data, pdc_write_data): Add cast.
(aix_thread_resume): Use PTRACE_TYPE_ARG5.
* rs6000-nat.c (rs6000_ptrace64): Use PTRACE_TYPE_ARG5.
(rs6000_ptrace_ldinfo): Change type of 'ldi' local to void
pointer, and cast return to gdb_byte pointer.
Now that gdb/gdbserver compile as C++ programs by default, the s390
GNU/Linux build started failing with:
In file included from ../../src/gdb/common/common-defs.h:64:0,
from ../../src/gdb/defs.h:28,
from ../../src/gdb/s390-linux-nat.c:22:
../../src/gdb/s390-linux-nat.c: In function ‘void fetch_regset(regcache*, int, int, int, const regset*)’:
../../src/gdb/../include/libiberty.h:711:38: error: invalid conversion from ‘void*’ to ‘gdb_byte* {aka unsigned char*}’ [-fpermissive]
# define alloca(x) __builtin_alloca(x)
^
../../src/gdb/s390-linux-nat.c:297:19: note: in expansion of macro ‘alloca’
gdb_byte *buf = alloca (regsize);
^
etc.
gdb/ChangeLog:
2016-04-21 Pedro Alves <palves@redhat.com>
* s390-linux-nat.c (fetch_regset, store_regset, check_regset): Use
void * instead of gdb_byte *.
gdb/gdbserver/ChangeLog:
2016-04-21 Pedro Alves <palves@redhat.com>
* linux-s390-low.c (s390_collect_ptrace_register)
(s390_supply_ptrace_register, s390_get_hwcap): Use gdb_byte * and
add casts.
(s390_check_regset): Use void * instead of gdb_byte *.
This makes --enable-build-with-cxx be "yes" by default.
One must now configure with --enable-build-with-cxx=no in order to
build with a C compiler.
gdb/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* build-with-cxx.m4 (GDB_AC_BUILD_WITH_CXX): Default to yes.
* configure: Renegerate.
gdb/gdbserver/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* configure: Renegerate.
Building in C++ mode caught a bug here:
.../src/gdb/darwin-nat.c: In function 'ptid_t darwin_decode_message(mach_msg_header_t*, darwin_thread_t**, inferior**, target_waitstatus*)':
.../src/gdb/darwin-nat.c:1016:25: error: invalid conversion from 'int' to 'gdb_signal' [-fpermissive]
status->value.sig = WTERMSIG (wstatus);
^
gdb/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* darwin-nat.c (darwin_decode_message): Use gdb_signal_from_host.
Fixes, with x86_64-apple-darwin15-gcc (gcc 5.3.0):
.../src/gdb/aarch64-tdep.c: In function 'aarch64_record_load_store':
.../src/gdb/aarch64-tdep.c:3479:67: error: passing argument 3 of 'regcache_raw_read_unsigned' from incompatible pointer type [-Werror=incompatible-pointer-types]
bits (aarch64_insn_r->aarch64_insn, 16, 20), ®_rm_val);
^
In file included from .../src/gdb/regcache.h:23:0,
from .../src/gdb/gdbarch.h:69,
from .../src/gdb/defs.h:620,
from .../src/gdb/aarch64-tdep.c:21:
.../src/gdb/common/common-regcache.h:60:29: note: expected 'ULONGEST * {aka long unsigned int *}' but argument is of type 'uint64_t * {aka long long unsigned int *}'
extern enum register_status regcache_raw_read_unsigned
^
gdb/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* aarch64-tdep.c (aarch64_record_load_store): Change type of
'reg_rm_val' local to ULONGEST.
Fixes, with gcc 5.3.0:
.../src/gdb/darwin-nat.c: In function 'void darwin_resume_thread(inferior*, darwin_thread_t*, int, int)':
.../src/gdb/darwin-nat.c:731:21: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
(caddr_t)thread->gdb_port, nsignal);
^
.../src/gdb/darwin-nat.c:84:35: note: in definition of macro 'PTRACE'
darwin_ptrace(#CMD, CMD, (PID), (ADDR), (SIG))
^
thread->gdb_port is an unsigned int, caddr_t is a void pointer.
gdb/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* darwin-nat.c (darwin_resume_thread): Add uintptr_t cast.
Fix the compilation failure by including arch/arm-linux.h in
aarch32-linux-nat.c.
gdb:
2016-04-20 Yao Qi <yao.qi@linaro.org>
* aarch32-linux-nat.c: Include "arch/arm-linux.h".
This patch moves macro ARM_CPSR_GREGNUM to arch/arm-linux.h so that it
can be used in GDBserver side.
gdb:
2016-04-20 Yao Qi <yao.qi@linaro.org>
* arm-linux-tdep.h (ARM_CPSR_GREGNUM): Move it to ...
* arch/arm-linux.h: ... here.
gdb/gdbserver:
2016-04-20 Yao Qi <yao.qi@linaro.org>
* linux-aarch32-low.c: Include "arch/arm-linux.h".
(arm_fill_gregset): Use ARM_CPSR_GREGNUM rather than magic
number 16.
(arm_store_gregset): Likewise.
FreeBSD versions older than 11.0 use char * as the type of ss_sp in
stack_t instead of the standards-defined void *. C++ allows a char *
pointer to be converted to a void *, so it is safe to cast the return
value of xmalloc to char * if ss_sp is either a char * or void *.
Just always use the cast to char * since that is less ugly than having
to add a special case.
gdb/ChangeLog:
* main.c (setup_alternate_signal_stack): Cast to char *.
In record_linux_system_call there are some cases with identical
handling. These are merged together to reduce code duplication.
gdb/ChangeLog:
* linux-record.c (record_linux_system_call): Merge handling for
readlink/recv/read and pipe/pipe2.
In the previous patch a new set of target descriptions
(i386|amd64)-avx-mpx were added being same as the (i386|amd64)-mpx.
This patch removes AVX feature from (i386|amd64)-mpx target
description set.
This way the (i386|amd64)avx_mpx(_linux|) set has AVX and MPX features
and (i386|amd64)mpx(_linux|) only MPX.
2016-04-14 Walfred Tedeschi <walfred.tedeschi@intel.com>
* features/i386/amd64-mpx-linux.xml: Remove AVX feature.
* features/i386/amd64-mpx.xml: Remove AVX feature.
* features/i386/i386-mpx-linux.xml: Remove AVX feature.
* features/i386/i386-mpx.xml: Remove AVX feature.
* features/i386/amd64-mpx-linux.c: Regenerate.
* features/i386/amd64-mpx.c: Regenerate.
* features/i386/i386-mpx-linux.c: Regenerate.
* features/i386/i386-mpx.c: Regenerate.
* regformats/i386/amd64-mpx-linux.dat: Regenerate.
* regformats/i386/amd64-mpx.dat: Regenerate.
* regformats/i386/i386-mpx-linux.dat: Regenerate.
* regformats/i386/i386-mpx.dat: Regenerate.
The current MPX target descriptions assume that MPX is always combined
with AVX, however that's not correct. We can have machines with MPX
and without AVX; or machines with AVX and without MPX.
This patch adds new target descriptions for machines that support
both MPX and AVX, as duplicates of the existing MPX descriptions.
The following commit will remove AVX from the MPX-only descriptions.
2016-04-16 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* amd64-linux-tdep.c (features/i386/amd64-avx-mpx-linux.c):
New include.
(amd64_linux_core_read_description): Add case for
X86_XSTATE_AVX_MPX_MASK.
(_initialize_amd64_linux_tdep): Call initialize_tdesc_amd64_avx_mpx_linux.
* amd64-linux-tdep.h (tdesc_amd64_avx_mpx_linux): New definition.
* amd64-tdep.c (features/i386/amd64-avx-mpx.c): New include.
(amd64_target_description): Add case for X86_XSTATE_AVX_MPX_MASK.
(_initialize_amd64_tdep): Call initialize_tdesc_amd64_avx_mpx.
* common/x86-xstate.h (X86_XSTATE_MPX_MASK): Remove AVX bits.
(X86_XSTATE_AVX_MPX_MASK): New case.
* features/Makefile (i386/i386-avx-mpx, i386/i386-avx-mpx-linux)
(i386/amd64-avx-mpx, i386/amd64-avx-mpx-linux): New rules.
(i386/i386-avx-mpx-expedite, i386/i386-avx-mpx-linux-expedite)
(i386/amd64-avx-mpx-expedite, i386/amd64-avx-mpx-linux-expedite):
New expedites.
* i386-linux-tdep.c (features/i386/i386-avx-mpx-linux.c): New
include.
(i386_linux_core_read_description): Add case
X86_XSTATE_AVX_MPX_MASK.
(_initialize_i386_linux_tdep): Call
initialize_tdesc_i386_avx_mpx_linux.
* i386-linux-tdep.h (tdesc_i386_avx_mpx_linux): New include.
* i386-tdep.c (features/i386/i386-avx-mpx.c): New include.
(i386_target_description): Add case for X86_XSTATE_AVX_MPX_MASK.
* x86-linux-nat.c (x86_linux_read_description): Add case for
X86_XSTATE_AVX_MPX_MASK.
* features/i386/amd64-avx-mpx-linux.xml: New file.
* features/i386/i386-avx-mpx-linux.xml: New file.
* features/i386/i386-avx-mpx.xml: New file.
* features/i386/amd64-avx-mpx.xml: New file.
* features/i386/amd64-avx-mpx-linux.c: Generated.
* features/i386/amd64-avx-mpx.c: Generated.
* features/i386/i386-avx-mpx-linux.c: Generated.
* features/i386/i386-avx-mpx.c: Generated.
* regformats/i386/amd64-avx-mpx-linux.dat: Generated.
* regformats/i386/amd64-avx-mpx.dat: Generated.
* regformats/i386/i386-avx-mpx-linux.dat: Generated.
* regformats/i386/i386-avx-mpx.dat: Generated.
gdb/gdbserver/ChangeLog:
* Makefile.in (clean): Add removal for i386-avx-mpx.c,
i386-avx-mpx-linux.c, amd64-avx-mpx.c and amd64-avx-mpx-linux.c.
(i386-avx-mpx.c, i386-avx-mpx-linux.c, amd64-avx-mpx.c)
(amd64-avx-mpx-linux.c): New rules.
(amd64-avx-mpx-linux-ipa.o, i386-avx-mpx-linux-ipa.o): New rule.
* configure.srv (srv_i386_regobj): Add i386-avx-mpx.o.
(srv_i386_linux_regobj): Add i386-avx-mpx-linux.o.
(srv_amd64_regobj): Add amd64-avx-mpx.o.
(srv_amd64_linux_regobj): Add amd64-avx-mpx-linux.o.
(srv_i386_xmlfiles): Add i386/i386-avx-mpx.xml.
(srv_amd64_xmlfiles): Add i386/amd64-avx-mpx.xml.
(srv_i386_linux_xmlfiles): Add i386/i386-avx-mpx-linux.xml.
(srv_amd64_linux_xmlfiles): Add i386/amd64-avx-mpx-linux.xml.
(ipa_i386_linux_regobj): Add i386-avx-mpx-linux-ipa.o.
(ipa_amd64_linux_regobj): Add amd64-avx-mpx-linux-ipa.o.
* linux-x86-low.c (x86_linux_read_description): Add case for
X86_XSTATE_AVX_MPX_MASK.
(x86_get_ipa_tdesc_idx): Add cases for avx_mpx.
(initialize_low_arch): Call init_registers_amd64_avx_mpx_linux and
init_registers_i386_avx_mpx_linux.
* linux-i386-ipa.c (get_ipa_tdesc): Add case for avx_mpx.
(initialize_low_tracepoint): Call
init_registers_i386_avx_mpx_linux.
* linux-amd64-ipa.c (get_ipa_tdesc): Add case for avx_mpx.
(initialize_low_tracepoint): Call
init_registers_amd64_avx_mpx_linux.
* linux-x86-tdesc.h (X86_TDESC_AVX_MPX): New enum value.
(init_registers_amd64_avx_mpx_linux, tdesc_amd64_avx_mpx_linux)
(init_registers_i386_avx_mpx_linux, tdesc_i386_avx_mpx_linux): New
declarations.
The ptrace args/return types detection doesn't work properly in C++
mode, on non-GNU/Linux hosts. For example, on gcc70 (NetBSD 5.1),
where the prototype is:
int ptrace(int, __pid_t, void*, int);
configure misdetects it as:
$ grep PTRACE_TYPE config.h
#define PTRACE_TYPE_ARG1 int
#define PTRACE_TYPE_ARG3 int *
#define PTRACE_TYPE_ARG4 int
/* #undef PTRACE_TYPE_ARG5 */
#define PTRACE_TYPE_RET int
resulting in:
../../src/gdb/amd64bsd-nat.c: In function 'void amd64bsd_fetch_inferior_registers(target_ops*, regcache*, int)':
../../src/gdb/amd64bsd-nat.c:56: warning: dereferencing type-punned pointer will break strict-aliasing rules
../../src/gdb/amd64bsd-nat.c: In function 'void amd64bsd_store_inferior_registers(target_ops*, regcache*, int)':
../../src/gdb/amd64bsd-nat.c:104: warning: dereferencing type-punned pointer will break strict-aliasing rules
../../src/gdb/amd64bsd-nat.c:110: warning: dereferencing type-punned pointer will break strict-aliasing rules
We could address this [1], however despite ptrace.m4's claim:
# Needs to be tested in C++ mode, to detect whether we need to cast
# the first argument to enum __ptrace_request.
it appears that there's actually no need to test in C++ mode. Always
running the ptrace tests in C mode works just the same on GNU/Linux.
I remember experimenting with several different ways to handle the
original issue back then, and maybe that was needed in some other
attempt and then I didn't realize it ended up not really necessary.
Confirmed that this fixes the NetBSD 5.1 C++ build, and confirmed that
C and C++ builds on Fedora 23 are unaffected.
[1] - https://sourceware.org/ml/gdb-patches/2016-04/msg00374.html
gdb/ChangeLog:
2016-04-18 Pedro Alves <palves@redhat.com>
* ptrace.m4 (GDB_AC_PTRACE): Don't run tests in C++ mode.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-04-18 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
After compiling a program which uses C++ references some optimizations may
convert the references into synthetic "pointers". Trying to print the address
of one of such synthetic references causes gdb to crash with the following
error:
(gdb) print &ref
/build/buildd/gdb-7.7.1/gdb/dwarf2loc.c:1624: internal-error: Should not be able to create a lazy value with an enclosing type
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Apparently, what was causing it was that value_addr returns a copy of the value
that represents the reference with its type set to T* instead of T&. However,
its enclosing_type is left untouched, which fails a check made in
read_pieced_value. We only see the crash happen for references that are
synthetic because they're treated as pieced values, thus the call to
read_pieced_value.
On a related note, it seems that in general there are all sorts of breakage
when working with synthetic references. This is reported here:
https://sourceware.org/bugzilla/show_bug.cgi?id=19893
gdb/ChangeLog:
2016-04-18 Martin Galvan <martin.galvan@tallertechnologies.com>
* valops.c (value_addr): For C++ references, set the copied value's
enclosing_type as well.
gdb/testsuite/ChangeLog:
2016-04-18 Martin Galvan <martin.galvan@tallertechnologies.com>
* gdb.dwarf2/implref.exp: New file.
2016-04-18 Yao Qi <yao.qi@linaro.org>
Revert:
2016-04-15 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (thumb_stack_frame_destroyed_p): Return zero if
PC is far from the end of function.
On:
$ uname -a
NetBSD gcc70.fsffrance.org 5.1 NetBSD 5.1 (GENERIC) #0: Sat Nov 6 13:19:33 UTC 2010 builds@b6.netbsd.org:/home/builds/ab/netbsd-5-1-RELEASE/amd64/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/amd64/compile/GENERIC amd64
The link fails with:
(...)
d-exp.o: In function `parse_number':
../../src/gdb/d-exp.y:762: multiple definition of `yydefred'
ada-exp.o:/home/palves/gdb/build/gdb/ada-lex.c:925: first defined here
ld: Warning: size of symbol `yydefred' changed from 464 in ada-exp.o to 336 in d-exp.o
Makefile:1404: recipe for target 'gdb' failed
NetBSD's yacc uses a "yydefred" symbol that we missed renaming in the
Ada parser. All other gdb parsers do this already.
gdb/ChangeLog:
2016-04-16 Pedro Alves <palves@redhat.com>
* ada-exp.y (yydefred): Define as ada_yydefred.
Compiling gdb with --enable-build-with-cxx --disable-nls, we get:
.../src/gdb/ada-lang.c:7657:16: error: invalid conversion from ‘const char*’ to ‘char*’ [-fpermissive]
type_str = (type != NULL
^
In file included from .../src/gdb/common/common-defs.h:67:0,
from .../src/gdb/defs.h:28,
from .../src/gdb/ada-lang.c:21:
.../src/gdb/common/gdb_locale.h:40:27: error: invalid conversion from ‘const char*’ to ‘char*’ [-fpermissive]
# define _(String) (String)
^
.../src/gdb/ada-lang.c:7730:46: note: in expansion of macro ‘_’
char *name_str = name != NULL ? name : _("<null>");
^
Makefile:1140: recipe for target 'ada-lang.o' failed
gdb/ChangeLog:
2016-04-15 Pedro Alves <palves@redhat.com>
* ada-lang.c (ada_lookup_struct_elt_type): Constify 'type_str' and
'name_str' locals.
With libipt's headers installed, a build with --enable-build-with-cxx
fails with:
.../src/gdb/btrace.c: In function ‘btrace_insn_flag pt_btrace_insn_flags(const pt_insn*)’:
.../src/gdb/btrace.c:734:33: error: invalid conversion from ‘int’ to ‘btrace_insn_flag’ [-fpermissive]
enum btrace_insn_flag flags = 0;
^
.../src/gdb/btrace.c:737:11: error: invalid conversion from ‘int’ to ‘btrace_insn_flag’ [-fpermissive]
flags |= BTRACE_INSN_FLAG_SPECULATIVE;
^
gdb/ChangeLog:
2016-04-15 Pedro Alves <palves@redhat.com>
* btrace.c (pt_btrace_insn_flags): Change return type to
btrace_insn_flags. Use btrace_insn_flags for local.
This makes the MIPS Linux backends recognize TRAP_BRKPT and
TRAP_HWBKPT in siginfo.si_code in addition to SI_KERNEL, since Linux
4.6 now reports the finer-grained si_code values too.
Refs:
https://sourceware.org/ml/gdb-patches/2016-02/msg00756.htmlhttps://sourceware.org/ml/gdb-patches/2016-04/msg00090.html
On kernels that report SI_KERNEL (<= 4.5), we'll enter the "ambiguous"
path of save_stop_reason:
if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
&& GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
{
/* The si_code is ambiguous on this arch -- check debug
registers. */
if (!check_stopped_by_watchpoint (lp))
lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
}
while on kernels that report the finer-grained si_code values (>= 4.6),
we'll enter the corresponding branches:
else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
{
}
else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
{
...
gdb/ChangeLog:
2016-04-15 Pedro Alves <palves@redhat.com>
* nat/linux-ptrace.h [__mips__] (GDB_ARCH_IS_TRAP_BRKPT): Also
accept TRAP_BRKPT.
[__mips__] (GDB_ARCH_IS_TRAP_HWBKPT): Also accept TRAP_HWBKPT.
thumb_stack_frame_destroyed_p scans the instructions from PC to the
end of the function, but if PC is far from the end of pc, we don't
have to scan, because PC should be in epilogue if it is still
far from the end of the function. The criterion I use here is 16
bytes, which is more than 4 instructions.
Regression tested on aarch64-linux with mutli-arch debug.
gdb:
2016-04-15 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (thumb_stack_frame_destroyed_p): Return zero if
PC is far from the end of function.
On:
$ uname -a
NetBSD gcc70.fsffrance.org 5.1 NetBSD 5.1 (GENERIC) #0: Sat Nov 6 13:19:33 UTC 2010 builds@b6.netbsd.org:/home/builds/ab/netbsd-5-1-RELEASE/amd64/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/amd64/compile/GENERIC amd64
With:
$ g++ -v
Using built-in specs.
Target: x86_64--netbsd
Configured with: /usr/src/tools/gcc/../../gnu/dist/gcc4/configure --enable-long-long --disable-multilib --enable-threads --disable-symvers --build=x86_64-unknown-netbsd4.99.72 --host=x86_64--netbsd --target=x86_64--netbsd --enable-__cxa_atexit
Thread model: posix
gcc version 4.1.3 20080704 prerelease (NetBSD nb2 20081120)
I saw:
cc1plus: warnings being treated as errors
../../src/gdb/ctf.c: In function 'void ctf_save_metadata_header(trace_write_handler*)':
../../src/gdb/ctf.c:267: warning: format not a string literal, argument types not checked
cc1plus: warnings being treated as errors
../../src/gdb/cli/cli-cmds.c: In function 'void alias_command(char*, int)':
../../src/gdb/cli/cli-cmds.c:1428: warning: format not a string literal and no format arguments
../../src/gdb/cli/cli-cmds.c:1457: warning: format not a string literal and no format arguments
gdb/ChangeLog:
2016-04-14 Pedro Alves <palves@redhat.com>
* cli/cli-cmds.c (alias_usage_error): New function.
(alias_command): Use it.
* ctf.c (ctf_save_metadata_header): Inline metadata_fmt local in
ctf_save_write_metadata call.
On:
$ uname -a
NetBSD gcc70.fsffrance.org 5.1 NetBSD 5.1 (GENERIC) #0: Sat Nov 6 13:19:33 UTC 2010 builds@b6.netbsd.org:/home/builds/ab/netbsd-5-1-RELEASE/amd64/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/amd64/compile/GENERIC amd64
With:
$ g++ -v
Using built-in specs.
Target: x86_64--netbsd
Configured with: /usr/src/tools/gcc/../../gnu/dist/gcc4/configure --enable-long-long --disable-multilib --enable-threads --disable-symvers --build=x86_64-unknown-netbsd4.99.72 --host=x86_64--netbsd --target=x86_64--netbsd --enable-__cxa_atexit
Thread model: posix
gcc version 4.1.3 20080704 prerelease (NetBSD nb2 20081120)
I saw:
../../src/gdb/ada-typeprint.c: In function 'void print_fixed_point_type(type*, ui_file*)':
../../src/gdb/ada-typeprint.c:366: warning: passing 'float' for argument 2 to 'DOUBLEST ada_fixed_to_float(type*, LONGEST)'
../../src/gdb/value.c: In function 'LONGEST unpack_long(type*, const gdb_byte*)':
../../src/gdb/value.c:2833: warning: converting to 'LONGEST' from 'DOUBLEST'
../../src/gdb/value.c:2838: warning: converting to 'LONGEST' from 'DOUBLEST'
gdb/ChangeLog:
2016-04-14 Pedro Alves <palves@redhat.com>
* ada-typeprint.c (print_fixed_point_type): Don't pass float as
argument to function expecting LONGEST.
* value.c (unpack_long): Add casts to LONGEST.
When we attempt to debug a process using GDBserver in standard remote mode
without a symbol file on GDB's end, we may run into an issue where GDB cuts
the connection attempt short due to an error. The error is caused by not
being able to open a symbol file, like so:
--
(gdb) set sysroot
(gdb) tar rem :2345
Remote debugging using :2345
/proc/23769/exe: Permission denied.
(gdb) i r
The program has no registers now.
(gdb)
It should've been like this:
(gdb) set sysroot
(gdb) tar rem :2345
Remote debugging using :2345
warning: /tmp/symbol-file: Permission denied.
0xf7ddb2d0 in ?? ()
(gdb) i r
eax 0x0 0
ecx 0x0 0
edx 0x0 0
ebx 0x0 0
esp 0xffffdfa0 0xffffdfa0
ebp 0x0 0x0
esi 0x0 0
edi 0x0 0
eip 0xf7ddb2d0 0xf7ddb2d0
eflags 0x200 [ IF ]
cs 0x33 51
ss 0x2b 43
ds 0x0 0
es 0x0 0
fs 0x0 0
gs 0x0 0
(gdb)
This is caused by a couple of function calls within exec_file_locate_attach
that can potentially throw errors.
The following patch guards both exec_file_attach and symbol_file_add_main to
prevent the errors from disrupting the connection process.
There was also a case where native GDB tripped on this problem, but it was
mostly fixed by bf74e428bc.
Regression-tested on x86-64/Ubuntu.
gdb/ChangeLog:
2016-04-13 Luis Machado <lgustavo@codesourcery.com>
* exec.c (exec_file_locate_attach): Guard a couple functions
that can throw errors.
(exception_print_same): New helper function.
Reverse debugging against a remote target that does reverse debugging
itself (with the bs/bc packets) always trips on:
(gdb) target remote localhost:...
(gdb) reverse-stepi
../../gdb/target.c:602: internal-error: default_execution_direction: to_execution_direction must be implemented for reverse async
I missed adding a to_execution_direction method to remote.c in commit
3223143295 (Adds target_execution_direction to make record targets
support async mode), GDB 7.4 time. Later, GDB 7.8 switched to
target-async on by default, making the regression user-visible by
default too.
Fix is simply to add the missing to_execution_direction implementation
to target remote.
Tested by Andi Kleen against Simics.
gdb/ChangeLog:
2016-04-13 Pedro Alves <palves@redhat.com>
PR remote/19840
* remote.c (struct remote_state) <last_resume_exec_dir>: New
field.
(new_remote_state): Default last_resume_exec_dir to EXEC_FORWARD.
(remote_open_1): Reset last_resume_exec_dir to EXEC_FORWARD.
(remote_resume): Store the last execution direction.
(remote_execution_direction): New function.
(init_remote_ops): Install it as to_execution_direction target_ops
method.
Now that we don't ever throw GDB exceptions from signal handlers [1],
we can switch back to having TRY/CATCH implemented in terms of C++
try/catch instead of sigjmp/longjmp.
[1] - https://sourceware.org/ml/gdb-patches/2016-03/msg00351.html
Tested on x86_64 Fedora 23, native and gdbserver.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* common/common-exceptions.h (GDB_XCPT_TRY): Update comment.
[__cplusplus] (GDB_XCPT): Define as GDB_XCPT_TRY.
Now that we don't ever throw GDB exceptions from signal handlers [1],
we can switch to have TRY/CATCH implemented in terms of plain
setjmp/longjmp instead of sigsetjmp/siglongjmp.
In https://sourceware.org/ml/gdb-patches/2015-02/msg00114.html, Yichun
Zhang mentions a 11%/14%+ speedup in his GDB python scripts with a
patch that did something similar to only a specific set of TRY/CATCH
calls.
[1] - https://sourceware.org/ml/gdb-patches/2016-03/msg00351.html
Tested on x86_64 Fedora 23, native and gdbserver.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <buf>: Now a
'jmp_buf' instead of SIGJMP_BUF.
(exceptions_state_mc_init): Change return type to 'jmp_buf'.
(throw_exception): Use longjmp instead of SIGLONGJMP.
* common/common-exceptions.h: Include <setjmp.h> instead of
"gdb_setjmp.h".
(exceptions_state_mc_init): Change return type to 'jmp_buf'.
[GDB_XCPT == GDB_XCPT_SJMP] (TRY): Use setjmp instead of
SIGSETJMP.
* cp-support.c: Include "gdb_setjmp.h".
This finally gets rid of immediate_quit (and surrounding
infrustruture), as nothing sets it anymore.
gdb_call_async_signal_handler was only necessary in order to handle
immediate_quit. We can just call mark_async_signal_handler directly
on all hosts now.
In turn, we can clean up mingw-hdep.c's gdb_select a bit, as
sigint_event / sigint_handler is no longer needed.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* defs.h: Update comments on SIGINT handling.
(immediate_quit): Delete declaration.
* event-loop.c (call_async_signal_handler): Delete.
* event-loop.h (call_async_signal_handler): Delete declaration.
(mark_async_signal_handler): Update comments.
(gdb_call_async_signal_handler): Delete declaration.
* event-top.c (handle_sigint): Call mark_async_signal_handler
instead of gdb_call_async_signal_handler.
* exceptions.c (prepare_to_throw_exception): Remove reference to
immediate_quit.
(exception_fprintf): Remove comments about immediate_quit.
* mingw-hdep.c (sigint_event, sigint_handler): Delete.
(gdb_select): Don't wait on sigint_event.
(gdb_call_async_signal_handler): Delete.
(_initialize_mingw_hdep): Delete.
* posix-hdep.c (gdb_call_async_signal_handler): Delete.
* utils.c (immediate_quit): Delete.
remote.c is the last user of immediate_quit. It's relied on to
immediately break the initial remote connection sync up, if the user
does Ctrl-C, assuming that was because the target isn't responding.
At that stage, since the connection isn't synced yet, disconnecting is
the only safe thing to do. This commit reworks that, to not rely on
throwing from the SIGINT signal handler.
So, this commit:
- Introduces the concept of a "quit handler". This is used to
override what does the QUIT macro do when the quit flag is set.
- Makes the "struct serial" reachar / write code call QUIT in the
partial read/write loops, so the current quit handler is invoked
whenever a serial->read_prim / serial->write_prim returns EINTR.
- Makes the "struct serial" reachar / write code call
interruptible_select instead of gdb_select, so that QUITs are
detected in a race-free manner.
- Stops remote.c from setting immediate_quit during the initial
connection.
- Instead, we install a custom quit handler whenever we're calling
into the serial code. This custom quit handler knows to immediately
throw a quit when we're in the initial connection setup, and
otherwise defer handling the quit/Ctrl-C request to later, when
we're safely out of a packet command/response sequence. This also
is what is now responsible for handling "double Ctrl-C because
target connection is stuck/wedged."
- remote.c no longer installs a specialized SIGINT handlers, and
instead re-uses the quit flag. Since we want to rely on the QUIT
macro, the SIGINT handler must also set the quit. And the easiest
is just to not install custom SIGINT handler in remote.c. Let the
standard SIGINT handler do its job of setting the quit flag.
Centralizing SIGINT handlers seems like a good thing to me, anyway.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* defs.h (quit_handler_ftype, quit_handler)
(make_cleanup_override_quit_handler, default_quit_handler): New.
(QUIT): Adjust comments.
* event-top.c (default_quit_handler): New function.
(quit_handler): New global.
(struct quit_handler_cleanup_data): New.
(restore_quit_handler, restore_quit_handler_dtor)
(make_cleanup_override_quit_handler): New.
(async_request_quit): Call QUIT.
* remote.c (struct remote_state) <got_ctrlc_during_io>: New field.
(async_sigint_remote_twice_token, async_sigint_remote_token):
Delete.
(remote_close): Update comments.
(remote_start_remote): Don't set immediate_quit. Set starting_up
earlier.
(remote_serial_quit_handler, remote_unpush_and_throw): New
functions.
(remote_open_1): Clear got_ctrlc_during_io. Set
remote_async_terminal_ours_p unconditionally.
(async_initialize_sigint_signal_handler)
(async_handle_remote_sigint, async_handle_remote_sigint_twice)
(remote_check_pending_interrupt, async_remote_interrupt)
(async_remote_interrupt_twice)
(async_cleanup_sigint_signal_handler, ofunc)
(sync_remote_interrupt, sync_remote_interrupt_twice): Delete.
(remote_terminal_inferior, remote_terminal_ours): Remove async
checks.
(remote_wait_as): Don't install a SIGINT handler in sync mode.
(readchar, remote_serial_write): Override the quit handler with
remote_serial_quit_handler.
(getpkt_or_notif_sane_1): Don't call QUIT.
(initialize_remote_ops): Don't install
remote_check_pending_interrupt.
(_initialize_remote): Don't create async_sigint_remote_token and
async_sigint_remote_twice_token.
* ser-base.c (ser_base_wait_for): Call QUIT and use
interruptible_select.
(ser_base_write): Call QUIT.
* ser-go32.c (dos_readchar, dos_write): Call QUIT.
* ser-unix.c (wait_for): Don't use VTIME. Always take the
gdb_select path, but call QUIT and interruptible_select.
* utils.c (maybe_quit): Call the current quit handler. Don't call
target_check_pending_interrupt.
(defaulted_query, prompt_for_continue): Override the quit handler
with the default quit handler.
The MI code only does output, so leave raw/cooked mode alone, as well
as the SIGINT handler. Restore terminal settings after output, while
at it. Also, a couple events missed calling target_terminal_ours
before output, even.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* mi/mi-interp.c (mi_new_thread): Put
target_terminal_ours_for_output in effect while outputting.
(mi_thread_exit): Use target_terminal_ours_for_output instead of
target_terminal_ours.
(mi_record_changed, mi_inferior_added, mi_inferior_appeared)
(mi_inferior_exit, mi_inferior_removed, mi_traceframe_changed)
(mi_tsv_created, mi_tsv_deleted, mi_tsv_modified)
(mi_breakpoint_created, mi_breakpoint_deleted)
(mi_breakpoint_modified, mi_solib_loaded, mi_solib_unloaded)
(mi_command_param_changed, mi_memory_changed)
(report_initial_inferior): Use target_terminal_ours_for_output
instead of target_terminal_ours. Restore terminal settings.
* mi/mi-main.c (mi_execute_command): Use
target_terminal_ours_for_output instead of target_terminal_ours.
Restore terminal settings.
Any time a caller calls query & friends / prompt_for_continue without
ensuring that gdb owns the terminal for input is a bug. So do that in
defaulted_query / prompt_for_continue directly instead.
An example of a case where we currently miss calling
target_terminal_ours is internal_error. Ever since defaulted_query
was made to use gdb_readline_callback, there's no way to answer the
internal error query if the internal error happens while the target is
has the terminal:
(gdb) c
Continuing.
.../src/gdb/linux-nat.c:1676: internal-error: linux_nat_resume: Assertion `dummy_counter < 10' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) _
Entering 'y' or 'n' does not work, GDB does not respond.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
PR gdb/19828
* gnu-nat.c (inf_validate_task_sc): Don't call
target_terminal_ours / target_terminal_inferior around query.
* i386-tdep.c (i386_record_lea_modrm, i386_process_record): Don't
call target_terminal_ours / target_terminal_inferior around
yquery.
* linux-record.c (record_linux_system_call): Don't call
target_terminal_ours / target_terminal_inferior around yquery.
* nto-procfs.c (interrupt_query): Don't call target_terminal_ours
/ target_terminal_inferior around query.
* record-full.c (record_full_check_insn_num): Remove
'set_terminal' parameter. Don't call target_terminal_ours /
target_terminal_inferior around query.
(record_full_message, record_full_registers_change)
(record_full_xfer_partial): Adjust.
* remote.c (interrupt_query): Don't call target_terminal_ours /
target_terminal_inferior around query.
* utils.c (defaulted_query): Install cleanup to restore target
terminal. Put target_terminal_ours_for_output in effect while
defaulted producing, and target_terminal_ours in in effect while
handling input.
(prompt_for_continue): Install cleanup to restore target terminal.
Put target_terminal_ours in in effect while handling input.
Some of the error paths in these functions leak.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* utils.c (defaulted_query, prompt_for_continue): Free temporary
strings with cleanups, instead of xfree.
We're only doing output here, so leave raw/cooked mode alone, as well
as the SIGINT handler.
And restore terminal settings, while at it.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* utils.c (vwarning, internal_vproblem): Use
make_cleanup_restore_target_terminal and
target_terminal_ours_for_output.
We're only doing output here, so leave raw/cooked mode alone, as well
as the SIGINT handler.
No need to restore terminal settings, we'll set inferior modes on the
following resume.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* infcmd.c (post_create_inferior, prepare_one_step): Use
target_terminal_ours_for_output instead of target_terminal_ours.
We're only doing output here, so leave raw/cooked mode alone, as well
as the SIGINT handler.
Restore terminal settings after output, while at it.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* exceptions.c (print_flush): Use target_terminal_ours_for_output
instead of target_terminal_ours, and restore target terminal with
a cleanup.
We're only doing output here, so leave raw/cooked mode alone, as well
as the SIGINT handler.
Restore terminal settings after output, while at it.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* cp-support.c (gdb_demangle): Use target_terminal_ours_for_output
instead of target_terminal_ours, and restore target terminal with
a cleanup.
A couple wrong things here
- We should not use target_terminal_ours when all we want is output.
We should use target_terminal_ours_for_output instead, which
preserves raw/cooked terminal modes, and SIGINT forwarding.
- Most importantly, relying on stderr output immediately preceding
the error/exception print isn't correct. The exception could be
caught and handled, for example; MI frontends won't display the
stderr part in an error dialog box. Etc.
This commit introduces a type_as_string helper that allows building a
full error string including type info.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* ada-lang.c (type_as_string, type_as_string_and_cleanup): New
functions.
(ada_lookup_struct_elt_type): Use type_as_string_and_cleanup.
- If serial->write_prim returns EINTR, ser_bas_write returns it to the
caller. This just looks wrong to me -- part of the output may have
already been sent, and there's no way for the caller to know that,
and thus no way for a caller to handle a partial write correctly.
- While ser-unix.c:ser_unix_read_prim retries on EINTR,
ser-tcp.c:net_read_prim does not.
This commit moves EINTR handling to the ser_base_write and
ser_base_readchar level, so all serial backends (at least those that
use it) end up handling EINTR consistently.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* ser-base.c (fd_event): Retry read_prim on EINTR.
(do_ser_base_readchar): Retry read_prim on EINTR.
(ser_base_write): Retry write_prim on EINTR.
* ser-unix.c (ser_unix_read_prim): Don't retry on EINTR here.
(ser_unix_write_prim): Remove comment.
If the user presses Ctrl-C immediately before target_terminal_inferior
is called and the target is resumed, instead of after, the Ctrl-C ends
up pending in the quit flag until the target next stops.
remote.c has this bit to handle this:
if (!target_is_async_p ())
{
ofunc = signal (SIGINT, sync_remote_interrupt);
/* If the user hit C-c before this packet, or between packets,
pretend that it was hit right here. */
if (check_quit_flag ())
sync_remote_interrupt (SIGINT);
}
But that's only reachable if async is off, while async is on by
default nowadays. It's also obviously not reacheable on native
targets.
This patch generalizes that to all targets.
We can't remove that remote.c bit yet, until we get rid of the sync
SIGINT handler though. That'll be done later in the series.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* remote.c (remote_pass_ctrlc): New function.
(init_remote_ops): Install it.
* target.c (target_terminal_inferior): Pass pending Ctrl-C to the
target.
(target_pass_ctrlc, default_target_pass_ctrlc): New functions.
* target.h (struct target_ops) <to_pass_ctrlc>: New method.
(target_pass_ctrlc, default_target_pass_ctrlc): New declarations.
* target-delegates.c: Regenerate.
In non-stop mode, "interrupt" results in a "stop with no signal",
while in all-stop mode, it results in a remote interrupt request /
stop with SIGINT. This is currently implemented in both the Linux and
remote target backends. Move it to the core code instead, making
target_interrupt specifically always about "Interrupting as if with
Ctrl-C", just like it is documented.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* infcmd.c (interrupt_target_1): Call target_stop is in non-stop
mode.
* linux-nat.c (linux_nat_interrupt): Delete.
(linux_nat_add_target): Don't install linux_nat_interrupt.
* remote.c (remote_interrupt_ns): Change return type to void.
Throw error if interrupting the target is not supported.
(remote_interrupt): Don't call the remote_stop_ns/remote_stop_as.
This call seems pointless. For instance, a SIGINT handler is only
installed later on. And if wasn't, I can't see why we'd want to lose
a Ctrl-C request.
Getting rid of this allows getting rid of clear_quit_flag.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* main.c (captured_main): Don't clear the quit flag.
I think this is reminiscent of the time when a longjmp would always
jump to the top level. Nowaways code that throw exceptions other than
a quit, which may even be caught and handled without reaching the top
level. Certainly such exceptions shouldn't clear an interrupt
request...
(We also need to get rid of prepare_to_throw_exception in order to be
able to just do "throw ex;" in C++.)
One could argue that we should clear the quit flag when we throw a
quit from the SIGINT handler, when immediate_quit is in effect, to
handle a race, here:
immediate_quit++;
QUIT;
... that's the usual pattern code must use when enabling
immediate_quit. The QUIT is there to catch the case of Ctrl-C having
already been pressed before immediate_quit was enabled. However, this
can happen:
immediate_quit++;
<< Ctrl-C pressed here too.
QUIT;
And in that case, if the quit flag was already set, it'll stay set
even after throwing a quit from the SIGINT handler. The end result is
a double quit. But OTOH, the user did press Ctrl-C two times. Since
I'm getting rid of immediate_quit, I'm not bothering with this.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* exceptions.c (prepare_to_throw_exception): Don't clear the quit
flag.
This just looks totally wrong to me, for completetly discarding a
user-requested Ctrl-C. I can't think of why we'd want do this here.
Actually, I digged the history, and found out that this has been here
since at least 7b4ac7e1ed (gdb-2.4, the initial revision, 1988), at
a time were we had a top level setjmp/longjmp, long before that got
wrapped in throw_exception and friends, and this code was in an
explicit loop, with the quit_flag cleared on every iteration, before
executing a command...
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* event-top.c (command_handler): Don't call clear_quit_flag.
Obviously not necessary since check_quit_flag clears the flag as side
effect.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* remote-sim.c (gdb_os_poll_quit): Don't call clear_quit_flag.
* remote.c (remote_wait_as): Don't call clear_quit_flag.
Now that we have an abstract for wakeable events, use it instead of a
(heavier) serial pipe.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* python/python.c: Include "ser-event.h".
(gdbpy_event_fds): Delete.
(gdbpy_serial_event): New.
(gdbpy_run_events): Change prototype. Use serial_event_clear
instead of serial_readchar.
(gdbpy_post_event): Use serial_event_set instead of serial_write.
(gdbpy_initialize_events): Use make_serial_event instead of
serial_pipe.
We have places where we call a blocking gdb_select expecting that a
Ctrl-C will unblock it. However, if the Ctrl-C is pressed just before
gdb_select, the SIGINT handler runs before gdb_select, and thus
gdb_select won't return.
For example gdb_readline_no_editing:
QUIT;
/* Wait until at least one byte of data is available. Control-C
can interrupt gdb_select, but not fgetc. */
FD_ZERO (&readfds);
FD_SET (fd, &readfds);
if (gdb_select (fd + 1, &readfds, NULL, NULL, NULL) == -1)
and stdio_file_read:
/* For the benefit of Windows, call gdb_select before reading from
the file. Wait until at least one byte of data is available.
Control-C can interrupt gdb_select, but not read. */
{
fd_set readfds;
FD_ZERO (&readfds);
FD_SET (stdio->fd, &readfds);
if (gdb_select (stdio->fd + 1, &readfds, NULL, NULL, NULL) == -1)
return -1;
}
return read (stdio->fd, buf, length_buf);
This is a race classically fixed with either the self-pipe trick, or
by blocking SIGINT and then using pselect instead of select.
Blocking SIGINT most of the time would mean that check_quit_flag (and
thus QUIT) would need to do a syscall every time it is called, which
sounds best avoided, since QUIT is called in many loops. Thus we take
the self-pipe trick route (wrapped in a serial event).
Instead of having all places that need this manually add an extra file
descriptor to the set of gdb_select's watched file descriptors, we
introduce a wrapper, interruptible_select, that does that.
The Windows version of gdb_select actually does not suffer from this,
because mingw-hdep.c:gdb_call_async_signal_handler sets a Windows
event that gdb_select always waits on. So this patch can be seen as
generalization of that technique. We can't remove that extra event
from mingw-hdep.c until we get rid of immediate_quit though.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* defs.h: Extend QUIT-related comments to mention
interruptible_select.
(quit_serial_event_set, quit_serial_event_clear): Declare.
* event-top.c: Include "ser-event.h" and "gdb_select.h".
(quit_serial_event): New global.
(async_init_signals): Make quit_serial_event.
(quit_serial_event_set, quit_serial_event_clear)
(quit_serial_event_fd, interruptible_select): New functions.
* extension.c (set_quit_flag): Set the quit serial event.
(check_quit_flag): Clear the quit serial event.
* gdb_select.h (interruptible_select): New declaration.
* guile/scm-ports.c (ioscm_input_waiting): Use
interruptible_select instead of gdb_select.
* top.c (gdb_readline_no_editing): Likewise.
* ui-file.c (stdio_file_read): Likewise.
GDB's core signal handling suffers from a classical signal handler /
mainline code race:
int
gdb_do_one_event (void)
{
...
/* First let's see if there are any asynchronous signal handlers
that are ready. These would be the result of invoking any of the
signal handlers. */
if (invoke_async_signal_handlers ())
return 1;
...
/* Block waiting for a new event. (...). */
if (gdb_wait_for_event (1) < 0)
return -1;
...
}
If a signal is delivered while gdb is blocked in the poll/select
inside gdb_wait_for_event, then the select/poll breaks with EINTR,
we'll loop back around and call invoke_async_signal_handlers.
However, if the signal handler runs between
invoke_async_signal_handlers and gdb_wait_for_event,
gdb_wait_for_event will block, until the next unrelated event...
The fix is to a struct serial_event, and register it in the set of
files that select/poll in gdb_wait_for_event waits on. The signal
handlers that defer work to invoke_async_signal_handlers call
mark_async_signal_handler, which is adjusted to also set the new
serial event in addition to setting a flag, and is thus now is
garanteed to immediately unblock the next gdb_select/poll call, up
until invoke_async_signal_handlers is called and the event is cleared.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* event-loop.c: Include "ser-event.h".
(async_signal_handlers_serial_event): New global.
(async_signals_handler, initialize_async_signal_handlers): New
functions.
(mark_async_signal_handler): Set
async_signal_handlers_serial_event.
(invoke_async_signal_handlers): Clear
async_signal_handlers_serial_event.
* event-top.c (async_init_signals): Call
initialize_async_signal_handlers.
This patch adds a new "event" struct serial type, that is an
abstraction specifically for waking up blocking waits/selects,
implemented on top of a pipe on POSIX, and on top of a native Windows
event (CreateEvent, etc.) on Windows.
This will be used to plug signal handler / mainline code races.
For example, GDB can indefinitely delay handling a quit request if the
user presses Ctrl-C between the last QUIT call and the next (blocking)
gdb_select call in the event loop:
QUIT;
<<< press ctrl-c here and end up blocked in gdb_select
indefinitely.
gdb_select (...); // whoops, SIGINT was already handled, no EINTR.
A global alone (either the quit flag, or the "ready" flag of the async
signal handlers in the event loop) is not sufficient.
To plug races such as these on POSIX systems, we have to register some
waitable file descriptor in the set of files gdb_select waits on, and
write to it from the signal handler. This is classically a pipe, and
the pattern called the self-pipe trick. On Linux, it could be a more
efficient eventfd instead, but I'm sticking with a pipe for
simplifity, as we need it for portability anyway.
(Alternatively, we could use pselect/ppoll, and block signals until
the pselect. The latter is not a design I think GDB could use,
because we want the QUIT macro to be super cheap, as it is used in
loops. Plus, Windows.)
This is a "struct serial" because Windows's gdb_select relies on that.
Windows's gdb_select, our "select" replacement, knows how to wait on
all kinds of handles (regular files, pipes, sockets, console, etc.)
unlike the native Windows "select" function, which can only wait on
sockets. Each file descriptor for a "serial" type that is not
normally waitable with WaitForMultipleObjects must have a
corresponding struct serial instance. gdb_select then internally
looks up the struct serial instance that wraps each file descriptor,
and asks it for the corresponding Windows waitable handle.
We could use serial_pipe() to create a "struct serial"-wrapped pipe
that is usable everywhere, including Windows. That's what currently
python/python.c uses for cross-thread posting of events.
However, serial_write and serial_readchar are not designed to be
async-signal-safe on POSIX hosts. It's easier to bypass those when
setting/clearing the event source.
And writing and a serial pipe is a bit heavy weight on Windows.
gdb_select requires an extra thread to wait on the pipe and several
Windows events, when a single manual-reset Windows event, with no
extra thread is sufficient.
The intended usage is simply:
- Call make_serial_event to create a serial event object.
- From the signal handler call serial_event_set to set the event.
- From mainline code, have select/poll wait for serial_event_fd(), in
addition to whatever other files you're about to wait for.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* Makefile.in (SFILES): Add ser-event.c.
(HFILES_NO_SRCDIR): Add ser-event.h.
(COMMON_OBS): Add ser-event.o.
* ser-event.c, ser-event.h: New files.
* serial.c (new_serial): New function, factored out from
(serial_fdopen_ops): ... this.
(serial_open_ops_1): New function, factored out from
(serial_open): ... this.
(serial_open_ops): New function.
* serial.h (struct serial): Forware declare.
(serial_open_ops): New declaration.
Not used by anything.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* serial.c (serial_open, serial_fdopen_ops, do_serial_close):
Remove references to name.
* serial.h (struct serial) <name>: Delete.
This code installs a custom signal handler that throws a quit
exception if remote_fio_no_longjmp is not set.
AFAICS, the only real reason for this might have been to unblock the
ui_file_read call, in remote_fileio_func_read. But ever since:
2009-11-13 Daniel Jacobowitz <dan@codesourcery.com>
* ui-file.c (stdio_file_read): Call gdb_select before read.
at:
https://sourceware.org/ml/gdb-patches/2009-11/msg00321.html
that call is interruptible.
This is not only useful for switching to native C++ exceptions, but
AFAICS, also fixes a potential mess up of the remote protocol
connection, since there are target_read_memory calls done while
remote_fio_no_longjmp is clear. If the user presses ctrl-c while GDB
is sending or receiving a packet, we'll stop the communication
immediately, at a point where it isn't safe.
gdbserver doesn't support the File I/O remote protocol extension so I
can't test this.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* remote-fileio.c (sigint_fileio_token, remote_fio_no_longjmp):
Delete.
(async_remote_fileio_interrupt): Delete.
(remote_fileio_ctrl_c_signal_handler): Don't call the async signal
handler. Instead just always set the ctrl_c flag.
(remote_fileio_reply): Clear remote_fio_ctrl_c_flag before
re-enabling the SIGINT handler.
(remote_fileio_func_open, remote_fileio_func_close)
(remote_fileio_func_read, remote_fileio_func_write)
(remote_fileio_func_lseek, remote_fileio_func_rename)
(remote_fileio_func_unlink, remote_fileio_func_stat)
(remote_fileio_func_fstat, remote_fileio_func_gettimeofday)
(remote_fileio_func_isatty, remote_fileio_func_system)
(remote_fileio_request): Remove references to
remote_fio_no_longjmp.
(initialize_remote_fileio): Don't create an async signal handler.
immediate_quit used to be necessary back when prompt_for_continue used
blocking fread, but nowadays it uses gdb_readline_wrapper, which is
implemented in terms of a nested event loop, which already knows how
to react to SIGINT:
#0 throw_it (reason=RETURN_QUIT, error=GDB_NO_ERROR, fmt=0x9d6d7e "Quit", ap=0x7fffffffcb88)
at .../src/gdb/common/common-exceptions.c:324
#1 0x00000000007bab5d in throw_vquit (fmt=0x9d6d7e "Quit", ap=0x7fffffffcb88) at .../src/gdb/common/common-exceptions.c:366
#2 0x00000000007bac9f in throw_quit (fmt=0x9d6d7e "Quit") at .../src/gdb/common/common-exceptions.c:385
#3 0x0000000000773a2d in quit () at .../src/gdb/utils.c:1039
#4 0x000000000065d81b in async_request_quit (arg=0x0) at .../src/gdb/event-top.c:893
#5 0x000000000065c27b in invoke_async_signal_handlers () at .../src/gdb/event-loop.c:949
#6 0x000000000065aeef in gdb_do_one_event () at .../src/gdb/event-loop.c:280
#7 0x0000000000770838 in gdb_readline_wrapper (prompt=0x7fffffffcd40 "---Type <return> to continue, or q <return> to quit---")
at .../src/gdb/top.c:873
The need for the QUIT in stdin_event_handler is then exposed by the
gdb.base/double-prompt-target-event-error.exp test, which has:
# We're now stopped in a pagination query while handling a
# target event (printing where the program stopped). Quitting
# the pagination should result in only one prompt being
# output.
send_gdb "\003p 1\n"
Without that change we'd get:
Continuing.
---Type <return> to continue, or q <return> to quit---PASS: gdb.base/double-prompt-target-event-error.exp: ctrlc target event: continue: continue to pagination
^CpQuit
(gdb) 1
Undefined command: "1". Try "help".
(gdb) PASS: gdb.base/double-prompt-target-event-error.exp: ctrlc target event: continue: first prompt
ERROR: Undefined command "".
UNRESOLVED: gdb.base/double-prompt-target-event-error.exp: ctrlc target event: continue: no double prompt
Vs:
Continuing.
---Type <return> to continue, or q <return> to quit---PASS: gdb.base/double-prompt-target-event-error.exp: ctrlc target event: continue: continue to pagination
^CQuit
(gdb) p 1
$1 = 1
(gdb) PASS: gdb.base/double-prompt-target-event-error.exp: ctrlc target event: continue: first prompt
PASS: gdb.base/double-prompt-target-event-error.exp: ctrlc target event: continue: no double prompt
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* event-top.c (stdin_event_handler): Call QUIT;
(prompt_for_continue): Don't run with immediate_quit set.
As can be seen in the tui_redisplay_readline comment:
"The command could call prompt_for_continue and we must not restore
SingleKey so that the prompt and normal keymap are used."
immediate_quit is being used as proxy for "secondary prompt".
We have a better predicate nowadays, so use it.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* tui/tui-io.c (tui_redisplay_readline): Check
gdb_in_secondary_prompt_p instead of immediate_quit.
* tui/tui.c: Include top.h.
(tui_rl_startup_hook): Check gdb_in_secondary_prompt_p instead of
immediate_quit.
read_command_line is the only caller, and here we can assume we're
reading a regular file, not stdin.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* top.c (read_command_file): Inline command_loop here.
(command_loop): Delete.
AFAICS, immediate_quit was only needed here nowdays to be able to
interrupt gdb_readline_no_editing.
command_line_input can also take the gdb_readline_wrapper path, but
since that is built on top of the event loop (gdb_select / poll and
asynchronous signal handlers), it can be interrupted.
gdb/ChangeLog:
2016-04-12 Pedro Alves <palves@redhat.com>
* top.c: Include "gdb_select.h".
(gdb_readline_no_editing): Wait for input with gdb_select instead
of blocking in fgetc.
(command_line_input): Don't set immediate_quit.
I did a quick pass over value.c and value.h and made some of the accessor methods'
pass-by-reference parameters const-correct. Besides the obvious benefits, this is
required if we want to use them on values that are already declared as const
(such as the parameters to lval_funcs).
There's probably a lot more stuff that can be made const, here and elsewhere.
gdb/ChangeLog:
2016-04-08 Martin Galvan <martin.galvan@tallertechnologies.com>
* value.c (value_next): Make pass-by-reference parameters const-correct.
(value_parent): Likewise.
(value_enclosing_type): Likewise.
(value_lazy): Likewise.
(value_stack): Likewise.
(value_embedded_offset): Likewise.
(value_pointed_to_offset): Likewise.
(value_raw_address): Likewise.
(deprecated_value_modifiable): Likewise.
(value_free_to_mark): Likewise.
(value_release_to_mark): Likewise.
(internalvar_name): Likewise.
(readjust_indirect_value_type): Likewise.
(value_initialized): Likewise.
* value.h (value_next): Likewise.
(value_parent): Likewise.
(value_enclosing_type): Likewise.
(value_lazy): Likewise.
(value_stack): Likewise.
(value_embedded_offset): Likewise.
(value_pointed_to_offset): Likewise.
(value_raw_address): Likewise.
(deprecated_value_modifiable): Likewise.
(value_free_to_mark): Likewise.
(value_release_to_mark): Likewise.
(internalvar_name): Likewise.
(readjust_indirect_value_type): Likewise.
(value_initialized): Likewise.
Some test fails in gdb.reverse/break-reverse.exp on arm-linux lead me
seeing the following error message,
continue^M
Continuing.^M
Cannot remove breakpoints because program is no longer writable.^M
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Further execution is probably impossible.^M
^M
Breakpoint 3, bar () at /home/yao/SourceCode/gnu/gdb/git/gdb/testsuite/gdb.reverse/break-reverse.c:22^M
22 xyz = 2; /* break in bar */^M
(gdb) PASS: gdb.reverse/break-reverse.exp: continue to breakpoint: bar backward
this is caused by two entries in record_full_breakpoints, and their addr
is the same, but in_target_beneath is different.
during the record, we do continue,
Continuing.
infrun: clear_proceed_status_thread (Thread 13772.13772)
infrun: proceed (addr=0xffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: step-over queue now empty
infrun: resuming [Thread 13772.13772] for step-over
infrun: skipping breakpoint: stepping past insn at: 0x8620
Sending packet: $Z0,85f4,4#1d...Packet received: OK <----
.....
Sending packet: $vCont;c#a8...infrun: target_wait (-1.0.0, status) =
infrun: -1.0.0 [process -1],
infrun: status->kind = ignore
infrun: TARGET_WAITKIND_IGNORE
infrun: prepare_to_wait
infrun: target_wait (-1.0.0, status) =
infrun: -1.0.0 [process -1],
infrun: status->kind = ignore
infrun: TARGET_WAITKIND_IGNORE
infrun: prepare_to_wait
Packet received: T05swbreak:;0b:9cf5ffbe;0d:9cf5ffbe;0f:f4850000;thread:p35cc.35cc;core:1;
Sending packet: $Z0,85f4,4#1d...Packet received: OK <-----
....
Sending packet: $z0,85f4,4#3d...Packet received: OK <-----
we can see breakpoint on 0x85f4 are inserted *twice*, but only removed
once. That is fine to remote target, because Z/z packets are
idempotent, but there is a leftover in record_full_breakpoints
in record-full target. The flow can be described as below,
record_full_breakpoints remote target
-----------------------------------------------------------------------
forward execution, continue, in_target_beneath 1 breakpoint inserted
insert breakpoints on 0x85f4 in_target_beneath 1
twice
program stops,
remove breakpoint on 0x85f4 in_target_beneath 1 breakpoint removed
reverse execution, continue, in_target_beneath 1 none is requested
insert breakpoints on 0x85f4, in_target_beneath 0
program stops,
remote breakpoint on 0x85f4, in_target_beneath 0 request to remove,
but GDBserver
doesn't know
now, the question is why breakoint on 0x85f4 is inserted twice? One
is the normal breakpoint, and the other is the single step breakpoint.
GDB inserts single step breakpoint to do single step. When program
stops at 0x85f4, both of them are set on 0x85f4, and GDB deletes
single step breakpoint, so in update_global_location_list, this
breakpoint location is no longer found, GDB call
force_breakpoint_reinsertion to mark it condition_updated, and insert
it again.
The reason force_breakpoint_reinsertion is called to update the
conditions in the target side, because the conditions may be
changed. My original fix is to not call force_breakpoint_reinsertion
if OLD_LOC->cond is NULL, but it is not correct if another location
on the same address has condition, GDB doesn't produce condition for
target side, but GDB should do.
Then, I change my mind back to make record-full handling breakpoint
idempotent, to align with remote target. Before insert a new entry
into record_full_breakpoints, look for existing one on the same
address first. I also add an assert on
"bp->in_target_beneath == in_target_beneath", to be safer.
gdb:
2016-04-07 Yao Qi <yao.qi@linaro.org>
* record-full.c (record_full_insert_breakpoint): Return
early if entry on the address is found in
record_full_breakpoints.
I notice that bp_tgt won't be fully initialized if to_insert_breakpoint
isn't called in record_full_insert_breakpoint, and bp_tgt->reqstd_address
is zero, so an entry is added to record_full_breakpoints, but its address
is zero, which is wrong. This patch is to call gdbarch_breakpoint_from_pc
in the else branch to set bp_tgt->reqstd_address and bp_tgt->placed_size.
gdb:
2016-04-07 Yao Qi <yao.qi@linaro.org>
* record-full.c (record_full_insert_breakpoint): Set
bp_tgt->reqstd_address and bp_tgt->placed_size.
This patch eliminates an error thrown when accessing the value of a
pointer to a structure where the pointer has been optimized out and
'set print object' is 'on'. The error shows up as the rather ugly
value of the pointer variable in Eclipse.
If 'set print object' is 'on', GDB tries to determine the actual
(derived) type of the object rather than the declared type, which
requires dereferencing the pointer, which in this cases throws an
error because the pointer has been optimized out.
The fix is to simply ignore the 'print object on' setting for
pointers or references to structures when they have been optimized
out. This means we just get the declared type instead of the actual
type, because in this case that's the best that we can do.
To implement the fix, value_optimized_out was modified so that it
no longer throws an error when it fails to fetch the specified
value. Instead, it just checks value->optimized_out. If we can't
definitively say that the value is optimized out, then we assume
it is not.
gdb/ChangeLog:
2016-04-06 Don Breazeal <donb@codesourcery.com>
* value.c (value_actual_type): Don't try to get rtti type
of the value if it has been optimized out.
(value_optimized_out): If a memory access error occurs,
just check vaue->optimized_out.
It broke the compatibility with gdbserver-7.6 due to:
warning: remote target does not support file transfer, attempting to access files from local filesystem.
gdb/ChangeLog
2016-04-06 Jan Kratochvil <jan.kratochvil@redhat.com>
Revert the previous commit adding unknown_v_replies_ok.
With current FSF GDB HEAD and old FSF gdbserver I expected I could do:
gdb -ex 'file target:/root/redhat/threadit' -ex 'target remote :1234'
(supplying that unsupported qXfer:exec-file:read by "file")
But that does not work because:
Sending packet: $vFile:setfs:0#bf...Packet received: OK
Packet vFile:setfs (hostio-setfs) is supported
...
Sending packet: $vFile:setfs:104#24...Packet received: OK
"target:/root/redhat/threadit": could not open as an executable file: Invalid argument
GDB documentation says:
The valid responses to Host I/O packets are:
An empty response indicates that this operation is not recognized.
This "empty response" vs. "OK" was a bug in gdbserver < 7.7. It was fixed by:
commit e7f0d979dd
Author: Yao Qi <yao@codesourcery.com>
Date: Tue Dec 10 21:59:20 2013 +0800
Fix a bug in matching notifications.
Message-ID: <1386684626-11415-1-git-send-email-yao@codesourcery.com>
https://sourceware.org/ml/gdb-patches/2013-12/msg00373.html
2013-12-10 Yao Qi <yao@codesourcery.com>
* notif.c (handle_notif_ack): Return 0 if no notification
matches.
with unpatched old FSF gdbserver and patched FSF GDB HEAD:
gdb -ex 'file target:/root/redhat/threadit' -ex 'target remote :1234'
Sending packet: $vFile:setfs:0#bf...Packet received: OK
Packet vFile:setfs (hostio-setfs) is NOT supported
...
(gdb) info sharedlibrary
From To Syms Read Shared Object Library
0x00007ffff7ddbae0 0x00007ffff7df627a Yes (*) target:/lib64/ld-linux-x86-64.so.2
0x00007ffff7bc48a0 0x00007ffff7bcf514 Yes (*) target:/lib64/libpthread.so.0
gdb/ChangeLog
2016-04-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* remote.c (struct remote_state): New field unknown_v_replies_ok.
(packet_config_support): Read it.
(remote_start_remote): Set it.
currently:
$ gdbserver-7.9 :1234 true &
$ gdb -q -ex 'target remote :1234' # that -q is not relevant here
Remote debugging using :1234
warning: Could not load vsyscall page because no executable was specified
try using the "file" command first.
0x00007ffff7ddcc80 in ?? ()
(gdb) b main
No symbol table is loaded. Use the "file" command.
Make breakpoint pending on future shared library load? (y or [n]) _
Provide more suggestive message to use the "file" command.
gdb/ChangeLog
2016-04-06 Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <palves@redhat.com>
* exec.c (exec_file_locate_attach): Print warning for unsupported
target_pid_to_exec_file.
* symfile-mem.c (add_vsyscall_page): Remove the "file" command
message part.
This patch adds support for TYPE_CODE_ENUM values to be supplied
as right-hand side operand of the BINOP_REPEAT (@) operator. The
following should now work:
enum {
sz = 17
};
int
main ()
{
int arr[sz + 1] = { 0 };
return 0; /* line 9 here */
}
(gdb) b 9
(gdb) r
(gdb) p arr@sz
$1 = {0 <repeats 17 times>}
(gdb)
A couple of tests is also included in this patch to demonstrate that it is
working as intended.
gdb/Changelog:
2016-04-01 Artemiy Volkov <artemiyv@acm.org>
PR gdb/19820
* eval.c (evaluate_subexp_standard): Allow TYPE_CODE_ENUM to be
the type of BINOP_REPEAT's second operand.
gdb/testsuite/Changelog:
2016-04-01 Artemiy Volkov <artemiyv@acm.org>
PR gdb/19820
* gdb.base/printcmds.exp: Add artificial arrays tests.
Ref: https://sourceware.org/ml/gdb/2016-03/msg00023.html
GDB currently fails to fetch the list of already-registered JIT
modules on attach.
Nothing is calling jit_inferior_init, which is what is responsible for
walking the JIT object list at init time.
Despite the misleading naming, jit_inferior_created_hook ->
jit_inferior_init is only called when the inferior execs.
This regressed with the fix for PR gdb/13431 (03bef283c2):
https://sourceware.org/ml/gdb-patches/2012-02/msg00023.html which
removed the inferior_created (jit_inferior_created_observer)
observer.
Adding an inferior_created observer back fixes the issue.
In turn, this exposes a bug in jit_breakpoint_re_set_internal as well,
which is returning the wrong result when we already have the
breakpoint at the right address.
gdb/ChangeLog:
2016-03-31 Yichao Yu <yyc1992@gmail.com>
PR gdb/19858
* jit.c (jit_breakpoint_re_set_internal): Return 0 if we already
got the breakpoint at the right address.
(jit_inferior_created): New function.
(_initialize_jit): Install jit_inferior_created as
inferior_created observer.
Signed-off-by: Pedro Alves <palves@redhat.com>
When gdb is started in MI mode, the output of gdb.execute
command is in MI-format in case when it is executed from python stop
handler while for all other cases the output is in console-format.
To assure consistent output format, this is fixed by using the console
format for all python gdb command executions.
PR python/19743
gdb/ChangeLog:
2016-03-31 Catalin Udma <catalin.udma@freescale.com>
PR python/19743
* python/python.c (execute_gdb_command): Use console uiout
when executing gdb command.
* utils.c (restore_ui_out_closure): New structure.
(do_restore_ui_out): New function.
(make_cleanup_restore_ui_out): Likewise.
* utils.h (make_cleanup_restore_ui_out): Declare.
gdb/testsuite/ChangeLog:
2016-03-31 Catalin Udma <catalin.udma@freescale.com>
PR python/19743
* gdb.python/py-mi-events-gdb.py: New file.
* gdb.python/py-mi-events.c: New file.
* gdb.python/py-mi-events.exp: New file.
Signed-off-by: Catalin Udma <catalin.udma@freescale.com>
This removes support for:
| target | source |
|-------------------+-----------------------|
| target m32rsdi | gdb/remote-m32r-sdi.c |
| target mips | gdb/remote-mips.c |
| target pmon | gdb/remote-mips.c |
| target ddb | gdb/remote-mips.c |
| target rockhopper | gdb/remote-mips.c |
| target lsi | gdb/remote-mips.c |
That is:
- Remote M32R debugging over SDI.
- Debugging boards using the MIPS remote debugging protocol
over a serial line, PMON, and a few variants.
These are the last non-"target remote" remote targets in the tree, if
you don't count "target sim".
Refs:
https://sourceware.org/ml/gdb/2016-03/msg00004.htmlhttps://sourceware.org/ml/gdb-patches/2016-03/msg00580.html
gdb/ChangeLog:
2016-03-31 Pedro Alves <palves@redhat.com>
* NEWS: Mention that support for "target m32rsdi", "target mips",
"target pmon", "target ddb", "target rockhopper", and "target lsi"
was removed.
* Makefile.in (ALL_TARGET_OBS): Remove remote-m32r-sdi.o and
remote-mips.o.
(ALLDEPFILES): Remove remote-m32r-sdi.c and remote-mips.c.
* configure.tgt: Remove all references to remote-m32r-sdi.o and
remote-mips.o.
* mips-tdep.c (deprecated_mips_set_processor_regs_hack): Delete
function.
* mips-tdep.h (deprecated_mips_set_processor_regs_hack): Delete
declaration.
* remote-m32r-sdi.c, remote-mips.c: Delete files.
* symfile.c (generic_load, generic_load): Remove comments.
gdb/doc/ChangeLog:
2016-03-31 Pedro Alves <palves@redhat.com>
* gdb.texinfo (M32R/SDI): Delete node.
(MIPS Embedded): Remove references to the MIPS remote debugging
protocol, PMON and variants, and the associated commands.
Variable 'func''s type is CORE_ADDR, so it should be compared with 0
rather than NULL. This causes a build error.
This patch fixes this.
gdb:
2016-03-30 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (arm_epilogue_frame_this_id): Check 'func' against
0 rather than NULL.
Nowadays, GDB can't unwind successfully from epilogue on arm,
(gdb) bt
#0 0x76ff65a2 in shr1 () from /home/yao/Source/gnu/build/gdb/testsuite/gdb.reverse/shr1.sl
#1 0x0000869e in main () at /home/yao/Source/gnu/build/gdb/testsuite/../../../binutils-gdb/gdb/testsuite/gdb.reverse/solib-reverse.c:34
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) disassemble shr1
Dump of assembler code for function shr1:
....
0x76ff659a <+10>: adds r7, #12
0x76ff659c <+12>: mov sp, r7
0x76ff659e <+14>: ldr.w r7, [sp], #4
0x76ff65a2 <+18>: bx lr
End of assembler dump.
in this case, prologue unwinder is used. It analyzes the prologue and
get the offsets of saved registers to SP. However, in epilogue, the
SP has been restored, prologue unwinder gets the registers from the
wrong address, and even the frame id is wrong.
In reverse debugging, this case (program stops at the last instruction
of function) happens quite frequently due to the reverse execution.
There are many test fails due to missing epilogue unwinder.
This adds epilogue unwinder, but the frame cache is still get by
prologue unwinder except that SP is fixed up separately, because SP
is restored in epilogue.
This patch fixes many fails in solib-precsave.exp, and solib-reverse.exp.
gdb:
2016-03-30 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c: (arm_make_epilogue_frame_cache): New function.
(arm_epilogue_frame_this_id): New function.
(arm_epilogue_frame_prev_register): New function.
(arm_epilogue_frame_sniffer): New function.
(arm_epilogue_frame_unwind): New.
(arm_gdbarch_init): Append unwinder arm_epilogue_frame_unwind.
This patch is to refactor arm_stack_frame_destroyed_p, so that the code
can be used in both arm_stack_frame_destroyed_p and arm epilogue
unwinder I am going to add in the next patch. In fact, the code
is the same in two places, but checking whether it is thumb mode
is slightly different. arm_stack_frame_destroyed_p uses
arm_pc_is_thumb, and epilogue unwinder should use arm_frame_is_thumb.
gdb:
2016-03-30 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (arm_stack_frame_destroyed_p): Rename it ...
(arm_stack_frame_destroyed_p_1): ... here. Don't call
arm_pc_is_thumb.
(arm_stack_frame_destroyed_p): Call
thumb_stack_frame_destroyed_p and
arm_stack_frame_destroyed_p_1.
gdb/ChangeLog:
* python/py-utils.c (host_string_to_python_string): New function.
* python/python-internal.h (host_string_to_python_string): Declare it.
* python/py-*.c (*): Update all calls to
PyString_Decode (str, strlen (str), host_charset (), NULL);
to use host_string_to_python_string instead.
On powerpc64, qSymbol query may require gdb to read a function
descriptor, sending a vFile packet to gdbserver. Thus, we need
to handle 'v' packet in look_up_one_symbol.
vFile replies may be quite long, and require reallocating own_buf.
Since handle_v_requests assumes the buffer is the static global own_buf
from server.c and reallocates it, we need to make own_buf global and
use it from look_up_one_symbol instead of using our own auto variable.
I've also done the same change in relocate_instruction, just in case.
On gdb side, in remote_check_symbols, rs->buf may be clobbered by vFile
handling, yet we need its contents for the reply (the symbol name is
stored there). Allocate a new buffer instead.
This broke fast tracepoints on powerpc64, due to errors in reading IPA
symbols.
gdb/ChangeLog:
* remote.c (remote_check_symbols): Allocate own buffer for reply.
gdbserver/ChangeLog:
* remote-utils.c (look_up_one_symbol): Remove own_buf, handle 'v'
packets.
(relocate_instruction): Remove own_buf.
* server.c (own_buf): Make global.
(handle_v_requests): Make global.
* server.h (own_buf): New declaration.
(handle_v_requests): New prototype.
When gdb is used on core dump and PC is not pointing to a readable
memory read_memory_integer call in the xtensa_frame_cache throws an
error, making register inspection/backtracing impossible in that thread.
Use safe_read_memory_integer instead.
2016-03-29 Max Filippov <jcmvbkbc@gmail.com>
gdb/
* xtensa-tdep.c (xtensa_frame_cache): Change op1 type to LONGEST.
Use safe_read_memory_integer instead of read_memory_integer.
I happen to see a quotation mark is missing the following test,
gdb_test "break $end_location" \
"Breakpoint $decimal at .* line $end_location\." \
set breakpoint at end of main"
so the test result is
PASS: gdb.reverse/break-reverse.exp: set
This patch is to add the missing quotation mark back, and the test
result becomes
PASS: gdb.reverse/break-reverse.exp: set breakpoint at end of main
gdb/testsuite:
2016-03-24 Yao Qi <yao.qi@linaro.org>
* gdb.reverse/break-reverse.exp: Add quotation mark in the
test message.
This comment is out of date. We've already done that. Patch is to remove
it.
gdb:
2016-03-23 Yao Qi <yao.qi@linaro.org>
* gdbarch.sh (software_single_step): Remove comments.
* gdbarch.h: Regenerated.
This patch is to support some ARM median instructions in process
record. With this patch applied, these fails are fixed:
-FAIL: gdb.reverse/break-precsave.exp: run to end of main
-FAIL: gdb.reverse/break-precsave.exp: go to end of main forward
-FAIL: gdb.reverse/break-precsave.exp: end of record log
-FAIL: gdb.reverse/break-reverse.exp: continue to breakpoint: end
-FAIL: gdb.reverse/break-reverse.exp: end of record log
-FAIL: gdb.reverse/until-precsave.exp: run to end of main
-FAIL: gdb.reverse/until-precsave.exp: advance to marker2
-FAIL: gdb.reverse/until-precsave.exp: until func, not called by current frame
-FAIL: gdb.reverse/until-precsave.exp: reverse-advance to marker2
-FAIL: gdb.reverse/until-precsave.exp: reverse-finish from marker2
-FAIL: gdb.reverse/until-precsave.exp: reverse-advance to final return of factorial
-FAIL: gdb.reverse/until-precsave.exp: reverse-until to entry of factorial
-FAIL: gdb.reverse/until-reverse.exp: advance to marker2
-FAIL: gdb.reverse/until-reverse.exp: until func, not called by current frame
-FAIL: gdb.reverse/until-reverse.exp: reverse-advance to marker2
-FAIL: gdb.reverse/until-reverse.exp: reverse-finish from marker2
-FAIL: gdb.reverse/until-reverse.exp: reverse-advance to final return of factorial
-FAIL: gdb.reverse/until-reverse.exp: reverse-until to entry of factorial
gdb:
2016-03-21 Yao Qi <yao.qi@linaro.org>
* arm-tdep.c (arm_record_media): New.
(arm_record_ld_st_reg_offset): Call arm_record_media.
This patch is to canonicalize more syscalls on arm linux in process
record. In this patch, I also comment out some syscalls which isn't
handled by GDB now. With this patch applied, two fails are fixed.
-FAIL: gdb.reverse/fstatat-reverse.exp: continue to breakpoint: marker2
-FAIL: gdb.reverse/recvmsg-reverse.exp: continue to breakpoint: marker2
gdb:
2016-03-21 Yao Qi <yao.qi@linaro.org>
* arm-linux-tdep.c (arm_canonicalize_syscall): Canonicalize
more syscalls.
sparc_software_single_step is not used out of sparc-tdep.c, so this
patch makes it static.
gdb:
2016-03-18 Yao Qi <yao.qi@linaro.org>
* sparc-tdep.c (sparc_software_single_step): Make it static.
* sparc-tdep.h (sparc_software_single_step): Remove declaration.
I happen to see that 1 is returned in spu_software_single_step when
target_read_memory returns 1. It must be wrong. That patch changes
it to throwing an error. Note that I choose to throw error because I
find the code in the end of spu_software_single_step throws errors.
gdb:
2016-03-18 Yao Qi <yao.qi@linaro.org>
* spu-tdep.c (spu_software_single_step): Throw error when
target_read_memory fails.
currently
gdb -p <pid from a container>
will print:
warning: Target and debugger are in different PID namespaces; thread lists and other data are likely unreliable
It correctly states the problem but it does not say how to solve it.
Originally I wanted to suggest also the Docker "-p 1234:1234" parameter but
I see the containers are more general topic than just Docker (even LxC etc.).
According to Gary future GDBs should be able to work even without gdbserver.
But currently gdbserver is still required.
gdb/ChangeLog
2016-03-17 Jan Kratochvil <jan.kratochvil@redhat.com>
* linux-thread-db.c (check_pid_namespace_match): Extend the message.
This patch addresses a failure in
gdb.threads/forking-threads-plus-breakpoint.exp:
FAIL: gdb.threads/forking-threads-plus-breakpoint.exp: cond_bp_target=1:
detach_on_fork=on: inferior 1 exited (timeout)
Cause:
A fork event was reported to GDB before GDB knew about the parent
thread, followed immediately by a breakpoint event in a different
thread. The parent thread was subsequently added via
remote_notice_new_inferior in process_stop_reply, but when the thread
was added the thread_info.state was set to THREAD_STOPPED. The fork
event was then handled correctly, but when the fork parent was resumed
via a call to keep_going, the state was unchanged.
The breakpoint event was then handled, which caused all the
non-breakpoint threads to be stopped. When the breakpoint thread was
resumed, all the non-breakpoint threads were resumed via
infrun.c:restart_threads. Our old fork parent wasn't restarted,
because it still had thread_info.state set to THREAD_STOPPED.
Ultimately the program under debug hung waiting for a pthread_join
while the old fork parent was stopped forever by GDB.
Fix:
Since this is non-stop, then the bug is that the thread should have
been added in THREAD_RUNNING state. Consider that infrun may be
pulling target events out of the target_ops backend into its own event
queue, but, not process them immediately. E.g., infrun may be
stopping all threads temporarily for a step-over-breakpoint operation
for thread A (stop_all_threads). The waitstatus of all threads is
thus left pending in the thread structure (save_status), including the
fork event of thread B. Right at this point, if the user does "info
threads", that should show thread B (the fork parent) running, not
stopped, even if internally, gdb is holding it paused for a little
bit.
Thus if in non-stop mode, always add new threads in the external
user-visible THREAD_RUNNING state. Change remote_notice_new_inferior
to accept the internal executing state of the thread instead, with
EXECUTING set to 1 when we discover a thread that is running on the
target (such as through remote_update_thread_list), and 0 when the
thread is really paused (such as when we see a stop reply).
Tested on x86_64 Linux and Nios II Linux target with x86 Linux host.
gdb/ChangeLog:
2016-03-17 Pedro Alves <palves@redhat.com>
Don Breazeal <donb@codesourcery.com>
PR remote/19496
* infcmd.c (notice_new_inferior): Use the 'leave_running' argument
instead of checking the 'non_stop' global.
* remote.c (remote_add_thread): New parameter 'executing'. Use it
to set the new thread's executing state.
(remote_notice_new_inferior): Rename parameter 'running' to
'executing'. Always set the thread state to THREAD_RUNNING in
non-stop mode, and to THREAD_STOPPED in all-stop mode. Pass
EXECUTING to remote_add_thread and notice_new_inferior.
(remote_update_thread_list): Update to pass executing state, not
running state.
Represent new Linux syscalls for s390 and s390x in GDB's syscall info.
Add the syscalls from 355 (userfaultfd) up to 374 (mlock2) as well as
the previously reserved NUMA syscalls 268-270, 287, and 310.
gdb/ChangeLog:
* syscalls/s390-linux.xml: Add NUMA syscalls and new syscalls up
to 374.
* syscalls/s390x-linux.xml: Likewise.
The function record_linux_system_call() often records a memory area
whose address is contained in a register. So far this required two
function calls: one for fetching the register value, and another one for
recording the memory area. These two function calls are now merged into
a new local helper function, and all occurrences are adjusted. This
reduces the source code and makes it more readable.
gdb/ChangeLog:
* linux-record.c (record_mem_at_reg): New helper function.
(record_linux_system_call): Exploit new helper function where
applicable.
This patch added handling for some syscalls to linux-record.c:
https://sourceware.org/ml/gdb-patches/2015-10/msg00452.html
But for both `pipe' and `pipe2' the patch lacks a statement after an
`if', such that the following `break' is interpreted as the `if'-body
instead.
This adds the missing (return-) statements for the conditionals.
gdb/ChangeLog:
* linux-record.c (record_linux_system_call): Add missing return
statements to handling of pipe and pipe2 syscalls.
Arguments are passed in r0-r6 on arm linux syscall (both EABI and OABI).
This patch is to set arm_linux_record_tdep.arg{1-7} to the right
register number.
This patch fixes the following test failures...
-FAIL: gdb.reverse/getresuid-reverse.exp: check ruid record
-FAIL: gdb.reverse/getresuid-reverse.exp: check rgid record
-FAIL: gdb.reverse/pipe-reverse.exp: check pipe record
-FAIL: gdb.reverse/readv-reverse.exp: check readv record
-FAIL: gdb.reverse/readv-reverse.exp: check readv record
-FAIL: gdb.reverse/readv-reverse.exp: check readv record
-FAIL: gdb.reverse/readv-reverse.exp: check readv record
-FAIL: gdb.reverse/waitpid-reverse.exp: check waitpid record
gdb:
2016-03-16 Yao Qi <yao.qi@linaro.org>
* arm-linux-tdep.c (arm_linux_init_abi): Fix
arm_linux_record_tdep.arg1, arm_linux_record_tdep.arg2 and
arm_linux_record_tdep.arg3. Set arm_linux_record_tdep.arg4,
arm_linux_record_tdep.arg5, arm_linux_record_tdep.arg6, and
arm_linux_record_tdep.arg7.
lookup_symbol is often called with user input. Consequently, any
function called from lookup_symbol{,_in_language} should attempt to
deal with malformed input gracefully. After all, malformed user
input is not a programming/API error.
This patch does not attempt to find/correct all instances of this. It
only fixes locations in the code that trigger test suite failures.
This patch fixes PR breakpoints/18303, "Assertion: -breakpoint-insert
with windows paths of file in non-current directory".
The patch includes three new tests related to this. One is just
gdb.linespec/ls-errs.exp copied and converted to use C++ instead of C, and
to add a case using a file name containing a Windows-style logical drive
specifier. The others include an MI test to provide a regression test for
the specific case reported in PR 18303, and a C++ test for proper error
handling of access to a program variable when using a file scope specifier
that refers to a non-existent file.
Tested on x86_64 native Linux.
gdb/ChangeLog
2016-01-28 Keith Seitz <keiths@redhat.com>
PR breakpoints/18303
* cp-namespace.c (cp_lookup_bare_symbol): Change assertion to
look for "::" instead of simply ":".
(cp_search_static_and_baseclasses): Return null_block_symbol for
malformed input.
Remove assertions.
* cp-support.c (cp_find_first_component_aux): Do not return
a prefix length for ':' unless the next character is also ':'.
gdb/testsuite/ChangeLog
2016-01-28 Don Breazeal <donb@codesourcery.com>
* gdb.cp/scope-err.cc: New test program.
* gdb.cp/scope-err.exp: New test script.
* gdb.linespec/ls-errs.c (myfunction): Expanded to have multiple
lines and "set breakpoint here" comment.
* gdb.linespec/ls-errs.exp: Added C++ testing and new test case.
Fixed some whitespace and format issues.
* gdb.mi/mi-linespec-err-cp.cc: New test program.
* gdb.mi/mi-linespec-err-cp.exp: New test script.
If /proc is not mounted, GDB fails an assertion in find_new_threads_once:
Continuing.
.../src/gdb/linux-thread-db.c:1249: internal-error: find_new_threads_once: Assertion `!target_has_execution' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
That was supposed to catch misuses of td_ta_thr_iter, which is unsafe
for live debugging. However, if /proc is not mounted, we still
fallback to using it.
I didn't bother with a warning, because GDB already prints several
others related to failing to open /proc files.
gdb/ChangeLog:
2016-03-15 Pedro Alves <palves@redhat.com>
PR gdb/19676
* linux-thread-db.c (try_thread_db_load_1): Leave
info->td_ta_thr_iter_p NULL iff debugging a live process and we
have /proc access.
(find_new_threads_once): Assert that we have a non-NULL
info->td_ta_thr_iter_p instead of checking whether the target has
execution.
On GNU/Linux archs that support displaced stepping, if /proc is not
mounted, GDB gets stuck not able to step past breakpoints:
(gdb) c
Continuing.
dl_main (phdr=<optimized out>, phnum=<optimized out>, user_entry=<optimized out>, auxv=<optimized out>) at rtld.c:2163
2163 LIBC_PROBE (init_complete, 2, LM_ID_BASE, r);
Cannot find AT_ENTRY auxiliary vector entry.
(gdb) c
Continuing.
dl_main (phdr=<optimized out>, phnum=<optimized out>, user_entry=<optimized out>, auxv=<optimized out>) at rtld.c:2163
2163 LIBC_PROBE (init_complete, 2, LM_ID_BASE, r);
Cannot find AT_ENTRY auxiliary vector entry.
(gdb)
That's because GDB can't figure out where the scratch pad is.
This is a regression introduced by the earlier changes to make the
Linux native target always work in non-stop mode.
This commit makes GDB detect the case and fallback to stepping over
breakpoints in-line.
gdb/ChangeLog:
2016-03-15 Pedro Alves <palves@redhat.com>
PR gdb/19676
* infrun.c (displaced_step_prepare): Also disable displaced
stepping on NOT_SUPPORTED_ERROR.
* linux-tdep.c (linux_displaced_step_location): If reading auxv
fails, throw NOT_SUPPORTED_ERROR instead of generic error.
Add a new command 'maint info line-table' to display the contents of
GDB's internal line table structure. Useful when trying to understand
problems (within gdb) relating to line tables.
gdb/ChangeLog:
* symmisc.c (maintenance_info_line_tables): New function.
(maintenance_print_one_line_table): New function.
(_initialize_symmisc): Register 'maint info line-table' command.
* NEWS: Mention new command.
gdb/doc/ChangeLog:
* gdb.texinfo (Symbols): Document new 'maint info line-table'
command.
gdb/testsuite/ChangeLog:
* gdb.base/maint.exp: New tests for 'maint info line-table'.
gdb/ChangeLog:
* s390-linux-tdep.c (s390_ax_pseudo_register_collect): New function.
(s390_ax_pseudo_register_push_stack): New function.
(s390_gdbarch_init): Fill ax_pseudo_register_collect and
ax_pseudo_register_push_stack hooks.
This patch is a follow-up to "Add printf format specifier for printing
enumerator":
https://sourceware.org/ml/gdb-patches/2016-02/msg00144.html
Instead of having a solution specific to the printf command, Pedro
suggested adding a general purpose function $_as_string() that would
cover this use case and more.
So, in order to print the textual label of an enum, one can use:
(gdb) printf "Visiting node of type %s\n", $_as_string(node)
Visiting node of type NODE_INTEGER
gdb/ChangeLog:
* data-directory/Makefile.in (PYTHON_FILE_LIST): Install
gdb/function/as_string.py.
* python/lib/gdb/function/as_string.py: New file.
* NEWS: Mention the new $_as_string function.
gdb/testsuite/ChangeLog:
* gdb.python/py-as-string.exp: New file.
* gdb.python/py-as-string.c: New file.
gdb/doc/ChangeLog:
* gdb.texinfo (Convenience Functions): Document $_as_string.
I didn't manage to usefully split this further into smaller
independent pieces, so:
- Use "struct buffer" more.
- Split out the responsibility of composing a complete command line
from multiple input lines split with backslash
(
E.g.:
(gdb) print \
1 + \
2
$1 = 3
(gdb)
)
to a separate function. Note we don't need the separate
readline_input_state and more_to_come globals at all. They were
just obfuscating the logic.
- Factor out the tricky mostly duplicated code in
command_line_handler and command_line_input.
gdb/ChangeLog
2016-03-09 Pedro Alves <palves@redhat.com>
* event-top.c (more_to_come): Delete.
(struct readline_input_state): Delete.
(readline_input_state): Delete.
(get_command_line_buffer): New function.
(command_handler): Update comments. Don't handle NULL commands
here. Do not execute commented lines.
(command_line_append_input_line): New function.
(handle_line_of_input): New function, partly based on
command_line_handler and command_line_input.
(command_line_handler): Rewrite.
* event-top.h (command_handler): New declaration.
(command_loop): Defer command execution to command_handler.
(command_line_input): Update comments. Simplify, using struct
buffer and handle_line_of_input.
* top.h (struct buffer): New forward declaration.
(handle_line_of_input): New declaration.
There doesn't seem to be much point in trying to reuse this buffer.
Prefer simplicity instead.
(In case you're wondering whether this fixes an off-by-one: linelength
is misnamed; it's really a size including terminating null char.)
gdb/ChangeLog:
2016-03-09 Pedro Alves <palves@redhat.com>
* event-top.c (command_line_handler): Use xfree + xstrdup instead
of xrealloc + strcpy.
* main.c (captured_main): Use xstrdup instead of xmalloc plus
manual clear.
* top.c (saved_command_line): Rewrite comment.
(saved_command_line_size): Delete.
(command_line_input): Use xfree + xstrdup instead of xrealloc +
strcpy.
* top.h (saved_command_line_size): Delete declaration.
gdb/ChangeLog:
2016-03-09 Pedro Alves <palves@redhat.com>
* event-top.c: Include buffer.h.
(gdb_readline_no_editing_callback): Use struct buffer instead
of xrealloc.
gdb/ChangeLog:
2016-03-09 Pedro Alves <palves@redhat.com>
* common/buffer.h (buffer_grow_char): New function.
* top.c: Include buffer.h.
(gdb_readline_no_editing): Rename 'prompt_arg' parameter to
'prompt'. Use struct buffer instead of xrealloc.
Name this such that it's clearer that this is not a wrapper for the
real readline, but instead a replacement that provides no command line
editing features.
gdb/ChangeLog:
2016-03-09 Pedro Alves <palves@redhat.com>
* defs.h (gdb_readline): Delete declaration.
* top.c (gdb_readline): Rename to ...
(gdb_readline_no_editing): ... this, and make static.
These comments are out of date -- we no longer call gdb_readline. And
I think that mentioning the event loop is more useful here than
whatever GO32 issue had with gdb_readline, which may even no longer be
an issue.
gdb/ChangeLog:
2016-03-09 Pedro Alves <palves@redhat.com>
* utils.c (prompt_for_continue): Update comments.
Bernhard Heckel
Simon Marchi
Jon Turney
Tom Tromey
Pedro Alves
Nick Clifton
Markus Metzger
Yao Qi
Joel Brobecker
Martin Galvan
Jan Kratochvil
Alan Modra
Andrew Burgess
Yan-Ting Lin
Yao Qi
Gary Benson
Jon Boden
Andreas Schwab
Doug Evans
Trevor Saunders
Thomas Preud'homme
Ulrich Weigand
Don Breazeal
Kyrylo Tkachov
Eli Zaretskii
Andreas Arnez
Keven Boell
Edjunior Barbosa Machado
Maciej W. Rozycki
Doug Evans
John Baldwin
Walfred Tedeschi
Luis Machado
Artemiy Volkov
Yichao Yu
Marcin Kościelnicki
Catalin Udma
Max Filippov
Simon Marchi
Jose E. Marchesi