[A test I wrote stumbled on a libthread_db issue related to thread
event breakpoints. See glibc PR17705:
[nptl_db: stale thread create/death events if debugger detaches]
https://sourceware.org/bugzilla/show_bug.cgi?id=17705
This patch avoids that whole issue by making GDB stop using thread
event breakpoints in the first place, which is good for other reasons
as well, anyway.]
Before PTRACE_EVENT_CLONE (Linux 2.6), the only way to learn about new
threads in the inferior (to attach to them) or to learn about thread
exit was to coordinate with the inferior's glibc/runtime, using
libthread_db. That works by putting a breakpoint at a magic address
which is called when a new thread is spawned, or when a thread is
about to exit. When that breakpoint is hit, all threads are stopped,
and then GDB coordinates with libthread_db to read data structures out
of the inferior to learn about what happened. Then the breakpoint is
single-stepped, and then all threads are re-resumed. This isn't very
efficient (stops all threads) and is more fragile (inferior's thread
list in memory may be corrupt; libthread_db bugs, etc.) than ideal.
When the kernel supports PTRACE_EVENT_CLONE (which we already make use
of), there's really no need to use libthread_db's event reporting
mechanism to learn about new LWPs. And if the kernel supports that,
then we learn about LWP exits through regular WIFEXITED wait statuses,
so no need for the death event breakpoint either.
GDBserver has been likewise skipping the thread_db events for a long
while:
https://sourceware.org/ml/gdb-patches/2007-10/msg00547.html
There's one user-visible difference: we'll no longer print about
threads being created and exiting while the program is running, like:
[Thread 0x7ffff7dbb700 (LWP 30670) exited]
[New Thread 0x7ffff7db3700 (LWP 30671)]
[Thread 0x7ffff7dd3700 (LWP 30667) exited]
[New Thread 0x7ffff7dab700 (LWP 30672)]
[Thread 0x7ffff7db3700 (LWP 30671) exited]
[Thread 0x7ffff7dcb700 (LWP 30668) exited]
This is exactly the same behavior as when debugging against remote
targets / gdbserver. I actually think that's a good thing (and as
such have listed this in the local/remote parity wiki page a while
ago), as the printing slows down the inferior. It's also a
distraction to keep bothering the user about short-lived threads that
she won't be able to interact with anyway. Instead, the user (and
frontend) will be informed about new threads that currently exist in
the program when the program next stops:
(gdb) c
...
* ctrl-c *
[New Thread 0x7ffff7963700 (LWP 7797)]
[New Thread 0x7ffff796b700 (LWP 7796)]
Program received signal SIGINT, Interrupt.
[Switching to Thread 0x7ffff796b700 (LWP 7796)]
clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:81
81 testq %rax,%rax
(gdb) info threads
A couple of tests had assumptions on GDB thread numbers that no longer
hold.
Tested on x86_64 Fedora 20.
gdb/
2014-01-09 Pedro Alves <palves@redhat.com>
Skip enabling event reporting if the kernel supports
PTRACE_EVENT_CLONE.
* linux-thread-db.c: Include "nat/linux-ptrace.h".
(thread_db_use_events): New function.
(try_thread_db_load_1): Check thread_db_use_events before enabling
event reporting.
(update_thread_state): New function.
(attach_thread): Use it. Check thread_db_use_events before
enabling event reporting.
(thread_db_detach): Check thread_db_use_events before disabling
event reporting.
(find_new_threads_callback): Check thread_db_use_events before
enabling event reporting. Update the thread's state if not using
libthread_db events.
gdb/testsuite/
2014-01-09 Pedro Alves <palves@redhat.com>
* gdb.threads/fork-thread-pending.exp: Switch to the main thread
instead of to thread 2.
* gdb.threads/signal-command-multiple-signals-pending.c (main):
Add barrier around each pthread_create call instead of around all
calls.
* gdb.threads/signal-command-multiple-signals-pending.exp (test):
Set a break on thread_function and have the child threads hit it
one at at a time.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On GNU/Linux, attaching to a multi-threaded program sometimes prints
out warnings like:
...
[New LWP 20700]
warning: unable to open /proc file '/proc/-1/status'
[New LWP 20850]
[New LWP 21019]
...
That happens because when a thread exits, and is joined, glibc does:
nptl/pthread_join.c:
pthread_join ()
{
...
if (__glibc_likely (result == 0))
{
/* We mark the thread as terminated and as joined. */
pd->tid = -1;
...
/* Free the TCB. */
__free_tcb (pd);
}
So if we attach or interrupt the program (which does an implicit "info
threads") at just the right (or rather, wrong) time, we can find and
return threads in the libthread_db/pthreads thread list with kernel
thread ID -1. I've filed glibc PR nptl/17707 for this. You'll find
more info there.
This patch handles this as a special case in GDB.
This is actually more than just a cosmetic issue. lin_lwp_attach_lwp
will think that this -1 is an LWP we're not attached to yet, and after
failing to attach will try to check we were already attached to the
process, using a waitpid call, which in this case ends up being
"waitpid (-1, ...", which obviously results in GDB potentially
discarding an event when it shouldn't...
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* thread-db.c (find_new_threads_callback): Ignore thread if the
kernel thread ID is -1.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (lin_lwp_attach_lwp): Assert that the lwp id we're
about to wait for is > 0.
* linux-thread-db.c (find_new_threads_callback): Ignore thread if
the kernel thread ID is -1.
... instead of relying on libthread_db.
I wrote a test that attaches to a program that constantly spawns
short-lived threads, which exposed several issues. This is one of
them.
On Linux, we need to attach to all threads of a process (thread group)
individually. We currently rely on libthread_db to list the threads,
but that is problematic, because libthread_db relies on reading data
structures out of the inferior (which may well be corrupted). If
threads are being created or exiting just while we try to attach, we
may trip on inconsistencies in the inferior's thread list. To work
around that, when we see a seemingly corrupt list, we currently retry
a few times:
static void
thread_db_find_new_threads_2 (ptid_t ptid, int until_no_new)
{
...
if (until_no_new)
{
/* Require 4 successive iterations which do not find any new threads.
The 4 is a heuristic: there is an inherent race here, and I have
seen that 2 iterations in a row are not always sufficient to
"capture" all threads. */
...
That heuristic may well fail, and when it does, we end up with threads
in the program that aren't under GDB's control. That's obviously bad
and results in quite mistifying failures, like e.g., the process dying
for seeminly no reason when a thread that wasn't attached trips on a
breakpoint.
There's really no reason to rely on libthread_db for this nowadays
when we have /proc mounted. In that case, which is the usual case, we
can list the LWPs from /proc/PID/task/. In fact, GDBserver is already
doing this. The patch factors out that code that knows to walk the
task/ directory out of GDBserver, and makes GDB use it too.
Like GDBserver, the patch makes GDB attach to LWPs and _not_ wait for
them to stop immediately. Instead, we just tag the LWP as having an
expected stop. Because we can only set the ptrace options when the
thread stops, we need a new flag in the lwp structure to keep track of
whether we've already set the ptrace options, just like in GDBserver.
Note that nothing issues any ptrace command to the threads between the
PTRACE_ATTACH and the stop, so this is safe (unlike one scenario
described in gdbserver's linux-low.c).
When we attach to a program that has threads exiting while we attach,
it's easy to race with a thread just exiting as we try to attach to
it, like:
#1 - get current list of threads
#2 - attach to each listed thread
#3 - ooops, attach failed, thread is already gone
As this is pretty normal, we shouldn't be issuing a scary warning in
step #3.
When #3 happens, PTRACE_ATTACH usually fails with ESRCH, but sometimes
we'll see EPERM as well. That happens when the kernel still has the
thread in its task list, but the thread is marked as dead.
Unfortunately, EPERM is ambiguous and we'll get it also on other
scenarios where the thread isn't dead, and in those cases, it's useful
to get a warning. To distiguish the cases, when we get an EPERM
failure, we open /proc/PID/status, and check the thread's state -- if
the /proc file no longer exists, or the state is "Z (Zombie)" or "X
(Dead)", we ignore the EPERM error silently; otherwise, we'll warn.
Unfortunately, there seems to be a kernel race here. Sometimes I get
EPERM, and then the /proc state still indicates "R (Running)"... If
we wait a bit and retry, we do end up seeing X or Z state, or get an
ESRCH. I thought of making GDB retry the attach a few times, but even
with a 500ms wait and 4 retries, I still see the warning sometimes. I
haven't been able to identify the kernel path that causes this yet,
but in any case, it looks like a kernel bug to me. As this just
results failure to suppress a warning that we've been printing since
about forever anyway, I'm just making the test cope with it, and issue
an XFAIL.
gdb/gdbserver/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-low.c (linux_attach_fail_reason_string): Move to
nat/linux-ptrace.c, and rename.
(linux_attach_lwp): Update comment.
(attach_proc_task_lwp_callback): New function.
(linux_attach): Adjust to rename and use
linux_proc_attach_tgid_threads.
(linux_attach_fail_reason_string): Delete declaration.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-nat.c (attach_proc_task_lwp_callback): New function.
(linux_nat_attach): Use linux_proc_attach_tgid_threads.
(wait_lwp, linux_nat_filter_event): If not set yet, set the lwp's
ptrace option flags.
* linux-nat.h (struct lwp_info) <must_set_ptrace_flags>: New
field.
* nat/linux-procfs.c: Include <dirent.h>.
(linux_proc_get_int): New parameter "warn". Handle it.
(linux_proc_get_tgid): Adjust.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this.
(linux_proc_pid_get_state): New function, factored out from
(linux_proc_pid_has_state): ... this. Add new parameter "warn"
and handle it.
(linux_proc_pid_is_gone): New function.
(linux_proc_pid_is_stopped): Adjust.
(linux_proc_pid_is_zombie_maybe_warn)
(linux_proc_pid_is_zombie_nowarn): New functions.
(linux_proc_pid_is_zombie): Use
linux_proc_pid_is_zombie_maybe_warn.
(linux_proc_attach_tgid_threads): New function.
* nat/linux-procfs.h (linux_proc_get_tgid): Update comment.
(linux_proc_get_tracerpid): Rename to ...
(linux_proc_get_tracerpid_nowarn): ... this, and update comment.
(linux_proc_pid_is_gone): New declaration.
(linux_proc_pid_is_zombie): Update comment.
(linux_proc_pid_is_zombie_nowarn): New declaration.
(linux_proc_attach_lwp_func): New typedef.
(linux_proc_attach_tgid_threads): New declaration.
* nat/linux-ptrace.c (linux_ptrace_attach_fail_reason): Adjust to
use nowarn functions.
(linux_ptrace_attach_fail_reason_string): Move here from
gdbserver/linux-low.c and rename.
(ptrace_supports_feature): If the current ptrace options are not
known yet, check them now, instead of asserting.
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason_string):
Declare.
Some debug output in linux-thread-db.c was being sent to gdb_stdout,
and some to gdb_stderr, while the right place to send debug output to is
gdb_stdlog.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* linux-thread-db.c (thread_db_find_new_threads_silently)
(try_thread_db_load_1, try_thread_db_load, thread_db_load_search)
(find_new_threads_once): Print debug output on gdb_stdlog.
I see the error message "access outside bounds of object referenced
via synthetic pointer" in the two fails below of mips gdb testing
print d[-2]^M
access outside bounds of object referenced via synthetic pointer^M
(gdb) FAIL: gdb.dwarf2/implptrconst.exp: print d[-2]
(gdb) print/d p[-1]^M
access outside bounds of object referenced via synthetic pointer^M
(gdb) FAIL: gdb.dwarf2/implptrpiece.exp: print/d p[-1]
in the first test, 'd[-2]' is processed by GDB as '* (&d[-2])'. 'd'
is a synthetic pointer, so its value is zero, the address of 'd[-2]'
is -2. In dwarf2loc.c:indirect_pieced_value,
/* This is an offset requested by GDB, such as value subscripts.
However, due to how synthetic pointers are implemented, this is
always presented to us as a pointer type. This means we have to
sign-extend it manually as appropriate. */
byte_offset = value_as_address (value);
if (TYPE_LENGTH (value_type (value)) < sizeof (LONGEST))
byte_offset = gdb_sign_extend (byte_offset,
8 * TYPE_LENGTH (value_type (value)));
byte_offset += piece->v.ptr.offset;
We know that the value is really an offset instead of address, so the
fix is to extract the value as an (signed) offset.
gdb:
2015-01-08 Pedro Alves <palves@redhat.com>
Yao Qi <yao@codesourcery.com>
* dwarf2loc.c (indirect_pieced_value): Don't call
gdb_sign_extend. Call extract_signed_integer instead.
* utils.c (gdb_sign_extend): Remove.
* utils.h (gdb_sign_extend): Remove declaration.
The special handling of C++ special symbol
generates symbols that have no language.
Those symbols cannot be displayed correctly in the backtrace stack.
See
https://sourceware.org/bugzilla/show_bug.cgi?id=17811
for details and examples in C++ and pascal language.
The patch below fixes this issue, by
setting language of new symbol before
special handling of special C++ symbols.
2015-01-07 Pierre Muller <muller@sourceware.org>
PR symtab/17811
* stabsread.c (define_symbol): Set language for C++ special symbols.
Currently when we start an inferior we have the inferior inherit our
terminal state. Under TUI, our terminal is highly modified by ncurses
and readline. So when starting an inferior under TUI, the inferior will
have a highly modified terminal state which will interfere with standard
I/O. For example,
$ gdb gdb
(gdb) break main
(gdb) run
(gdb) print puts ("a\nb")
a
b
$1 = 4
(gdb) [enter TUI mode]
(gdb) run
(gdb) [exit TUI mode]
(gdb) print puts ("a\nb")
a
b
$2 = 4
(gdb) print puts ("a\r\nb\r")
a
b
$3 = 6
As you can see, when we start the inferior under the regular interface,
puts() prints the text properly. But when we start the inferior under
TUI, puts() does not print the text properly. This is because when we
start the inferior under TUI it inherits our current terminal state
which has been modified by ncurses to, among other things, require an
explicit \r\n to print a new line. As a result the inferior performs
standard I/O in an unexpected way.
Because of this discrepancy, it doesn't seem like a good idea to have
the inferior inherit our _current_ terminal state for it may have been
modified by readline and/or ncurses. Instead, we should have the
inferior inherit a pristine snapshot of our terminal state taken before
readline or ncurses have had a chance to alter it. This enables the
inferior to run in a more accurate way, more closely mimicking the
program's behavior had it run standalone. And it fixes the above
mentioned issue.
Tested on x86_64-unknown-linux-gnu.
gdb/ChangeLog:
* terminal.h (set_initial_gdb_ttystate): Declare.
* inflow.c (initial_gdb_ttystate): New static variable.
(set_initial_gdb_ttystate): New setter.
(child_terminal_init_with_pgrp): Copy initial_gdb_ttystate
instead of our current terminal state.
* top.c (gdb_init): Call set_initial_gdb_ttystate.
This fixes a similar error as in the Python support code where
trying to create an empty array.
In guile/scm-type.c::tyscm_array_1, the funtion raises an exception
if N2 < N1:
if (n2 < n1)
{
gdbscm_out_of_range_error (func_name, SCM_ARG3,
But it should be doing so if N2 == N1 - 1, since that would simply
be an empty array, not an array with a negative length.
gdb/ChangeLog:
* guile/scm-type.c (tyscm_array_1): Do not raise out-of-range
error if N2 is equal to N1 - 1.
The following python command fails:
(gdb) python print gdb.lookup_type('char').array(1, 0)
Traceback (most recent call last):
File "<string>", line 1, in <module>
ValueError: Array length must not be negative
Error while executing Python code.
The above is trying to create an empty array, which is fairly command
in Ada.
gdb/ChangeLog:
* python/py-type.c (typy_array_1): Do not raise negative-length
exception if N2 is equal to N1 - 1.
gdb/testsuite/ChangeLog:
* gdb.python/py-type.exp: Add a couple test about empty
array creation, and negative-length array creation.
Make the extracted stack offset signed in the standard MIPS prologue
scanner, to simplify handling and make sure register offsets are correct
in all cases, especially where $fp equals the virtual frame pointer (old
GCC frames) and therefore offsets to save slots are negative.
* mips-tdep.c (mips32_scan_prologue): Make the extracted stack
offset signed.
This patch renames gdb/'s ChangeLog to ChangeLog-2014 and creates
a new one for 2015. config/djgpp/fnchange.lst is updated accordingly.
gdb/ChangeLog:
* config/djgpp/fnchange.lst: Add entry for gdb/ChangeLog-2014.
This patch removes documentation from some commands whose support has
been recently removed.
gdb/ChangeLog:
* NEWS: Document removal of "dll-symbols", "add-shared-symbol-files"
and "assf" commands.
gdb/doc/ChangeLog:
* gdb.texinfo (Files): Remove documentation of the
"add-shared-symbol-files" and "assf" commands.
(Cygwin Native): Remove documentation of the "dll-symbols"
command.
This patch removes a set of commands that have been deprecated for
a while, and which we agreed to remove after the GDB 7.8 release.
gdb/ChangeLog:
* windows-nat.c (safe_symbol_file_add_stub)
(safe_symbol_file_add_cleanup, safe_symbol_file_add)
(dll_symbol_command): Delete.
(_initialize_windows_nat): Delete local variable "c".
Remove "dll-symbols", "add-shared-symbol-files" and assf"
commands.
Tested by rebuilding GDB on x86-windows.
2014-12-29 Thomas Preud'homme <thomas.preudhomme@arm.com>
gdb/
* arm-tdep.c (arm_gdbarch_init): Remove casts in Tag_ABI_VFP_args
switch case statements.
*** bfd/ChangeLog ***
2014-12-25 Thomas Preud'homme <thomas.preudhomme@arm.com>
* elf32-arm.c (elf32_arm_merge_eabi_attributes): Handle new
Tag_ABI_VFP_args value and replace hardcoded values by enum
values.
(elf32_arm_post_process_headers): Set e_flags in ELF header
as hard float only when Tag_ABI_VFP_args is 1, using new enum
value AEABI_VFP_args_vfp to check that.
*** binutils/ChangeLog ***
2014-12-25 Thomas Preud'homme <thomas.preudhomme@arm.com>
* readelf.c (arm_attr_tag_ABI_VFP_args): Add "compatible".
*** gdb/ChangeLog ***
2014-12-25 Thomas Preud'homme <thomas.preudhomme@arm.com>
* arm-tdep.c (arm_gdbarch_init): Explicitely handle value 3 of
Tag_ABI_VFP_args. Also replace hardcoded values by enum values
in the switch handling the different values of Tag_ABI_VFP_args.
*** gold/ChangeLog ***
2014-12-25 Thomas Preud'homme <thomas.preudhomme@arm.com>
* arm.cc (Target_arm::do_adjust_elf_header): Set e_flags in ELF
header as hard float only when Tag_ABI_VFP_args is 1, using new
enum value AEABI_VFP_args_vfp to check that.
(Target_arm::merge_object_attributes): Handle new Tag_ABI_VFP_args
value and replace hardcoded values by enum values.
*** include/elf/ChangeLog ***
2014-12-25 Thomas Preud'homme <thomas.preudhomme@arm.com>
* arm.h: New AEABI_FP_number_model_* and AEABI_VFP_args_* enum
values.
*** ld/testsuite/ChangeLog ***
2014-12-25 Thomas Preud'homme <thomas.preudhomme@arm.com>
* ld-arm/attr-merge-2a.s: Add Tag_ABI_VFP_args.
* ld-arm/attr-merge-2b.s: Likewise.
* ld-arm/attr-merge-2.attr: Likewise.
* ld-arm/attr-merge-4a.s: Add Tag_ABI_FP_number_model and
Tag_ABI_VFP_args.
* ld-arm/attr-merge-4b.s: Likewise.
* ld-arm/attr-merge-4.attr: Likewise.
* ld-arm/attr-merge-6a.s: Likewise.
* ld-arm/attr-merge-6b.s: Likewise.
* ld-arm/attr-merge-6.attr: Add Tag_ABI_FP_number_model.
gdb/ChangeLog:
* ada-lang.c (user_select_syms): Only fetch symtab if symbol is
objfile-owned.
(cache_symbol): Ignore symbols that are not objfile-owned.
* block.c (block_objfile): New function.
(block_gdbarch): New function.
* block.h (block_objfile): Declare.
(block_gdbarch): Declare.
* c-exp.y (classify_name): Remove call to
language_lookup_primitive_type. No longer necessary.
* gdbtypes.c (lookup_typename): Call lookup_symbol_in_language.
Remove call to language_lookup_primitive_type. No longer necessary.
* guile/scm-symbol.c (syscm_gdbarch_data_key): New static global.
(syscm_gdbarch_data): New struct.
(syscm_init_arch_symbols): New function.
(syscm_get_symbol_map): Renamed from syscm_objfile_symbol_map.
All callers updated. Handle symbols owned by arches.
(gdbscm_symbol_symtab): Handle symbols owned by arches.
(gdbscm_initialize_symbols): Initialize syscm_gdbarch_data_key.
* language.c (language_lookup_primitive_type_1): New function.
(language_lookup_primitive_type): Call it.
(language_alloc_type_symbol): New function.
(language_init_primitive_type_symbols): New function.
(language_lookup_primitive_type_as_symbol): New function.
* language.h (struct language_arch_info) <primitive_type_symbols>:
New member.
(language_lookup_primitive_type): Add function comment.
(language_lookup_primitive_type_as_symbol): Declare.
* printcmd.c (address_info): Handle arch-owned symbols.
* python/py-symbol.c (sympy_get_symtab): Ditto.
(set_symbol): Ditto.
(sympy_dealloc): Ditto.
* symmisc.c (print_symbol): Ditto.
* symtab.c (fixup_symbol_section): Ditto.
(lookup_symbol_aux): Initialize block_found.
(basic_lookup_symbol_nonlocal): Try looking up the symbol as a
primitive type.
(initialize_objfile_symbol_1): New function.
(initialize_objfile_symbol): Call it.
(allocate_symbol): Call it.
(allocate_template_symbol): Call it.
(symbol_objfile): Assert symbol is objfile-owned.
(symbol_arch, symbol_symtab, symbol_set_symtab): Ditto.
* symtab.h (struct symbol) <owner>: Replaces member "symtab".
(struct symbol) <is_objfile_owned>: New member.
(SYMBOL_OBJFILE_OWNED): New macro.
* cp-namespace.c (cp_lookup_bare_symbol): New arg langdef.
All callers updated. Try to find the symbol as a primitive type.
(lookup_namespace_scope): New arg langdef. All callers updated.
Call cp_lookup_bare_symbol directly for simple bare symbols.
This patch fixes a problem when trying to insert a breakpoint on
a specific symbol defined in a specific file, eg:
break foo.c:func
This currently works for files in C/C++/Ada, etc, but doesn't always
work for Asm files. Analysis of the problem showed that this related
to a limitation in gas, which does not generate debug info for functions/
symbols. Thus, we have a symtab for the file ("info sources" shows
the file), but it contains no symbols.
When find_linespec_symbols is called in linespec_parse_basic, it calls
find_function_symbols, which uses add_matching_symbols_to_info to
collect all matching symbols.
That function does [pardon any mangled formatting]:
for (ix = 0; VEC_iterate (symtab_ptr, info->file_symtabs, ix, elt); ++ix)
{
if (elt == NULL)
{
iterate_over_all_matching_symtabs (info->state, name, VAR_DOMAIN,
collect_symbols, info,
pspace, 1);
search_minsyms_for_name (info, name, pspace);
}
else if (pspace == NULL || pspace == SYMTAB_PSPACE (elt))
{
/* Program spaces that are executing startup should have
been filtered out earlier. */
gdb_assert (!SYMTAB_PSPACE (elt)->executing_startup);
set_current_program_space (SYMTAB_PSPACE (elt));
iterate_over_file_blocks (elt, name, VAR_DOMAIN,
collect_symbols, info);
}
}
This iterates over the symtabs. In the failing use case, ELT is
non-NULL (points to the symtab for the .s file), so it calls
iterate_over_file_blocks. Herein is where the problem exists: it is
assumed that if NAME exists, it must exist in the given symtab -- a
reasonable assumption for "normal" (non-asm) cases. It never searches
minimal symbols (or in the global default symtab).
This patch fixes the problem by doing so. It is important to note that
iterating over minsyms is fairly expensive, so this patch only adds
that extra search if the language is language_asm and
iterate_over_file_blocks returns no symbols.
gdb/ChangeLog:
2014-12-20 Keith Seitz <keiths@redhat.com>
Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* linespec.c (struct collect_minsyms): Add new member `symtab'.
(add_minsym): Handle cases where info.symtab is non-NULL.
(search_minsyms_for_name): Add new parameter `symtab'.
Handle limiting searches to a specific symtab.
(add_matching_symtabs_to_info): Search through minimal symbols
for language_asm files for which no new symbols are found.
gdb/testsuite/ChangeLog:
2014-12-20 Mihail-Marian Nistor <mihail.nistor@freescale.com>
PR gdb/17394
* gdb.linespec/break-asm-file.c: New file.
* gdb.linespec/break-asm-file.exp: New file.
* gdb.linespec/break-asm-file0.s: New file.
* gdb.linespec/break-asm-file1.s: New file.
This patch is to add SDE OS ABI support in GDB, which has been used in
codesourcery gdb tree for some years.
gdb:
2014-12-19 Maciej W. Rozycki <macro@codesourcery.com>
Nigel Stephens <nigel@mips.com>
Chris Dearman <chris@mips.com>
Luis Machado <lgustavo@codesourcery.com>
* Makefile.in (ALL_TARGET_OBS): Add mips-sde-tdep.o.
(ALLDEPFILES): Add mips-sde-tdep.c.
* mips-sde-tdep.c: New file containg SDE specific code.
* configure.tgt (mips*-sde*-elf*): Add mips-sde-dep.o to
gdb_target_obs.
* defs.h (gdb_osabi): Add GDB_OSABI_SDE.
* osabi.c (gdb_osabi_names): Add SDE.
* NEWS: Mention the change.
I stumbled upon a few comments that I think are outdated.
Comment for elfread.c (elf_symfile_init): As far as history goes in git,
I don't see anything related to that.
Comment for elfread.c (elf_symfile_read): References a parameter that was
removed in 1999.
Comment for struct sym_fns/sym_offsets: References a parameter that was
changed in 1999.
gdb/ChangeLog:
* elfread.c (elf_symfile_init): Remove stale comment.
(elf_symfile_read): Same.
* symfile.h (struct sym_fns): Same.
This patch is the V2. V1 can be found in
https://sourceware.org/ml/gdb-patches/2012-05/msg00938.html
V2 is to address Joel's comment
<https://sourceware.org/ml/gdb-patches/2012-06/msg00289.html> about
keeping dumping floating point registers. Additionally, command
'info float' prints bits on nan2008 and abs2008.
------------------------------------------------------------------
The change below provides a MIPS-specific handler for the:
(gdb) info float
command. It provides information about the FPU type available (if any),
the FPU register width, and decodes the CP1 Floating Point Control and
Status Register (FCSR):
(gdb) print /x $fsr
$1 = 0xff83ffff
(gdb) info float
fpu type: double-precision
reg size: 32 bits
cond : 0 1 2 3 4 5 6 7
cause : inexact uflow oflow div0 inval unimp
mask : inexact uflow oflow div0 inval
flags : inexact uflow oflow div0 inval
rounding: -inf
flush : zero
One point to note about CP1.FCSR are the non-standard Flush-to-Nearest
and Flush-Override bits. They are not a part of the MIPS architecture and
take two positions reserved for an implementation-dependent use in the
architecture. They are present in all the FPU implementations made by
MIPS Technologies since the spin-off from SGI.
I haven't been able to track down a single other MIPS FPU implementation
that would make any use of these bits and they are required to be
hardwired to zero by the architecture specification if unimplemented.
Therefore I think it makes sense to report them in the current way.
GDB has no guaranteed access to the CP0 Processor Identification (PRId)
register to validate this feature properly and the ID information stored
in the CP1 Floating Point Implementation Register (FIR) is from my
experience not reliable enough (there's no Company ID available there for
once unlike in CP0.PRId and Processor ID is not guaranteed to be unique).
As a side note we should probably dump CP1.FIR information as well, as
there's useful stuff indicating some FPU features there. That's material
for another change however.
gdb/
2014-12-18 Nigel Stephens <nigel@mips.com>
Maciej W. Rozycki <macro@codesourcery.com>
* mips-tdep.c (print_fpu_flags): New function.
(mips_print_float_info): Likewise.
(mips_gdbarch_init): Install mips_print_float_info as gdbarch
print_float_info routine.
gdb/testsuite/
2014-12-18 Nigel Stephens <nigel@mips.com>
Maciej W. Rozycki <macro@codesourcery.com>
* gdb.base/float.exp: Handle the new output from "info float" on
MIPS targets.
This patch is to change print_float_info gdbarch method for the
following two reasons,
1. we want to add a default implementation of print_float_info to
dump the float pointer registers. It can be reused by backend to
print something more than float point registers.
2. we want to simplify the caller of print_float_info,
infcmd.c:print_float_info.
gdb:
2014-12-18 Yao Qi <yao@codesourcery.com>
* gdbarch.sh (print_float_info): Change its type from 'M' to 'm'.
* gdbarch.c: Re-generated.
* gdbarch.h: Likewise.
* infcmd.c (default_print_float_info): New function.
(print_float_info): Removed. Move code to
default_print_float_info.
(float_info): Adjust to call gdbarch_print_float_info.
* inferior.h (default_print_float_info): Declare it.
In infcmd.c:print_float_info, if the architecture doesn't have gdbarch
method print_float_info implemented and doesn't float reggroup, GDB
will prints "No floating-point info available for this processor."
The h8300 port doesn't have float registers, and don't need to
implement print_float_info. This patch is to remove it.
gdb:
2014-12-18 Yao Qi <yao@codesourcery.com>
* h8300-tdep.c (h8300_print_float_info): Remove.
(h8300_gdbarch_init): Remove the call to
set_gdbarch_print_float_info.
On Sun, 14 Dec 2014 07:00:28 +0100, Yao Qi wrote:
The build on mingw host is broken because mingw has no mkdtemp.
../../../git/gdb/compile/compile.c: In function 'get_compile_file_tempdir':
../../../git/gdb/compile/compile.c:194:3: error: implicit declaration of function 'mkdtemp' [-Werror=implicit-function-declaration]
tempdir_name = mkdtemp (tname);
^
../../../git/gdb/compile/compile.c:194:16: error: assignment makes pointer from integer without a cast [-Werror]
tempdir_name = mkdtemp (tname);
^
cc1: all warnings being treated as errors
In the end I have managed to test it by Wine myself:
$ wine build_win32/gdb/gdb.exe -q build_win32/gdb/gdb.exe -ex start -ex 'compile code 1' -ex 'set confirm no' -ex quit
[...]
Temporary breakpoint 1, main (argc=1, argv=0x241418) at ../../gdb/gdb.c:29
29 args.argc = argc;
Could not load libcc1.so: Module not found.
Even if it managed to load libcc1.so (it needs host-dependent name libcc1.dll)
then it would soon end up at least on:
default_infcall_mmap:
error (_("This target does not support inferior memory allocation by mmap."));
As currently there is only:
linux-tdep.c:
set_gdbarch_infcall_mmap (gdbarch, linux_infcall_mmap);
While one could debug Linux targets from MS-Windows host I find it somehow
overcomplicated now when we are trying to get it running at least on native
Linux x86*.
The 'compile' project needs a larger port effort to run on MS-Windows.
gdb/ChangeLog
2014-12-17 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix MinGW compilation.
* compile/compile.c (get_compile_file_tempdir): Call error if
!HAVE_MKDTEMP.
* config.in: Regenerate.
* configure: Regenerate.
* configure.ac (AC_CHECK_FUNCS): Add mkdtemp.
gdb/testsuite/ChangeLog
2014-12-17 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix MinGW compilation.
* gdb.compile/compile-ops.exp: Update untested message if
!skip_compile_feature_tests.
* gdb.compile/compile-setjmp.exp: Likewise.
* gdb.compile/compile-tls.exp: Likewise.
* gdb.compile/compile.exp: Likewise.
* lib/gdb.exp (skip_compile_feature_tests): Check also "Command not
supported on this host".
Anytime you can remove a symbol lookup that loops over all objfiles
is A Good Thing.
The call to lookup_static_symbol in valops.c:value_maybe_namespace_elt
is redundant with this call in cp_lookup_nested_symbol:
/* Now search all static file-level symbols. We have to do this
for things like typedefs in the class. We do not try to
guess any imported namespace as even the fully specified
namespace search is already not C++ compliant and more
assumptions could make it too magic. */
size = strlen (parent_name) + 2 + strlen (nested_name) + 1;
concatenated_name = alloca (size);
xsnprintf (concatenated_name, size, "%s::%s",
parent_name, nested_name);
sym = lookup_static_symbol (concatenated_name, VAR_DOMAIN);
if (sym != NULL)
return sym;
Earlier in value_maybe_namespace_elt we do this:
sym = cp_lookup_symbol_namespace (namespace_name, name,
get_selected_block (0), VAR_DOMAIN);
That sequence goes like:
value_maybe_namespace_elt
-> cp_lookup_symbol_namespace
-> cp_lookup_symbol_in_namespace
-> lookup_symbol_file
-> cp_lookup_nested_symbol
-> lookup_static_symbol
The call was added in commit 41f62f3939.
https://sourceware.org/ml/gdb-patches/2010-06/msg00663.html
With a part 2 here:
https://sourceware.org/ml/gdb-patches/2010-06/msg00664.html
At the time the call to lookup_static_symbol (spelled
lookup_static_symbol_aux at the time) was needed.
However, this patch, 8dea366bbe,
https://sourceware.org/ml/gdb-patches/2012-11/msg00387.html
augmented lookup_symbol_file to call cp_lookup_nested_symbol
and introduced the redundancy.
It's kinda buried, so it's totally not unexpected that this happened.
gdb/ChangeLog:
* valops.c (value_maybe_namespace_elt): Remove redundant call to
lookup_static_symbol.
gdb/ChangeLog:
* buildsym.c: Add comments describing how the buildsym machinery
is used by the various file formats.
(really_free_pendings): Enhance function comment.
See pending_macros to NULL. Simplify resetting pending_addrmap.
Call free_buildsym_compunit.
(free_buildsym_compunit): Set current_subfile to NULL.
(prepare_for_building): New function.
(start_symtab): Call it. Remove call to set_last_source_file.
(restart_symtab): New arg "cust". All callers updated.
Simplify, call prepare_for_building. Re-initialize buildsym_compunit.
(reset_symtab_globals): Enhance function comment.
Set local_symbols, file_symbols, global_symbols to NULL.
Set pending_macros to NULL. Simplify resetting pending_addrmap.
Call free_buildysym_compunit.
(end_symtab_without_blockvector): Delete. All callers updated.
(end_symtab_with_blockvector): Remove redundant call to
free_buildsym_compunit.
(augment_type_symtab): Remove arg "cust". All callers updated.
(buildsym_init): Remove resetting of free_pendings, file_symbols,
global_symbols, pending_blocks, pending_macros. Instead make
handling consistent with pending_addrmap: Assert value was reset
at end of previous symtab building. Initialize context_stack here.
Pedro Alves
Chen Gang
Yao Qi
Pierre Muller
Patrick Palka
Joel Brobecker
Doug Evans
Maciej W. Rozycki
Doug Evans
Jiong Wang
Anthony Green
Terry Guo
Mihail-Marian Nistor
Simon Marchi
Jan Kratochvil