The problem here is that if a thread other than gdb's main thread
gets a SIGCHLD (it's an asynchronous signal so the kernel will
essentially pick a random thread) then gdb will hang if it is
in sigsuspend when the SIGCHLD is delivered. The other thread
will see the signal and the sigsuspend won't "wake up".
Guile and libgc should be blocking SIGCHLD in their threads,
but we need to work with Guile 2.0 and libgc 7.4.
The problem first shows up in libgc 7.4 because it is the first
release that enables multiple marker threads by default.
gdb/ChangeLog:
PR 17247
* guile.c: #include <signal.h>.
(_initialize_guile): Block SIGCHLD while initializing Guile.
Replaces the following, which is reverted.
2014-07-26 Doug Evans <xdje42@gmail.com>
PR 17185
* configure.ac: Add check for header gc/gc.h.
Add check for function setenv.
* configure: Regenerate.
* config.in: Regenerate.
* guile/guile.c (_initialize_guile): Add workaround for libgc 7.4.0.
* acinclude.m4 (GDB_GUILE_PROGRAM_NAMES): New macro.
(GDB_GUILD_TARGET_FLAG, GDB_TRY_GUILD): New macros.
* configure.ac: Try to use guild to compile an scm file, if it fails
then disable guile support.
* configure: Regenerate.
* data-directory/Makefile.in (GUILE_SOURCE_FILES): Renamed from
GUILE_FILE_LIST.
(GUILE_COMPILED_FILES): New variable.
(GUILE_FILES) Update.
(GUILD, GUILD_TARGET_FLAG, GUILD_COMPILE_FLAGS): New variables.
(stamp-guile): Compile scm files.
* guile/guile.c (boot_guile_support): New function.
(standard_throw_args_p): New function.
(print_standard_throw_error, print_throw_error): New functions.
(handle_boot_error): New function.
(initialize_scheme_side): Rewrite to call boot_guile_support.
* guile/lib/gdb/boot.scm: Update %load-compiled-path. Load gdb.go.
* guile/lib/gdb/init.scm (%silence-compiler-warnings%): New function.
* data-directory/Makefile.in (GUILE_FILES): Add support.scm.
* guile/lib/gdb/support.scm: New file.
* guile/guile.c (gdbscm_init_module_name): Change to "gdb".
* guile/lib/gdb.scm: Load gdb/init.scm as an include file.
All uses updated.
* guile/lib/gdb/init.scm (SCM_ARG1, SCM_ARG2): Moved to support.scm.
All uses updated.
(%assert-type): Ditto, and renamed to assert-type.
(%exception-print-style): Delete.
testsuite/
* gdb.guile/types-module.exp: Add tests for wrong type arguments.
PR 17185 describes a problem with using gdb+guile with libgc 7.4.0.
The symptom is a hang in sigsuspend.
[The thread referenced in the PR has the details.]
It's not clear what the right fix is, or even where the bug is yet.
This patch applies the same workaround Guile has applied.
There is no functionality or real performance loss with this,
and Guile has been using it for awhile.
* configure.ac: Add check for header gc/gc.h.
Add check for function setenv.
* configure: Regenerate.
* config.in: Regenerate.
* guile/guile.c (_initialize_guile): Add workaround for libgc 7.4.0.
Currently there are many calls to help_list that pass the constant -1
as the "class" value. However, the parameter is declared as being of
type enum command_class, and uses of the constant violate this
abstraction.
This patch fixes the error everywhere it occurs in the gdb sources.
Tested by rebuilding.
2014-06-13 Tom Tromey <tromey@redhat.com>
* cp-support.c (maint_cplus_command): Pass all_commands, not -1,
to help_list.
* guile/guile.c (info_guile_command): Pass all_commands, not -1,
to help_list.
* tui/tui-win.c (tui_command): Pass all_commands, not -1, to
help_list.
* tui/tui-regs.c (tui_reg_command): Pass all_commands, not -1, to
help_list.Pass all_commands, not -1, to help_list.
* cli/cli-dump.c (dump_command, append_command)
(srec_dump_command, ihex_dump_command, tekhex_dump_command)
(binary_dump_command, binary_append_command): Pass all_commands,
not -1, to help_list.
* cli/cli-cmds.c (info_command, set_debug): Pass all_commands, not
-1, to help_list.
* valprint.c (set_print, set_print_raw): Pass all_commands, not
-1, to help_list.
* typeprint.c (set_print_type): Pass all_commands, not -1, to
help_list.
* top.c (set_history): Pass all_commands, not -1, to help_list.
* target-descriptions.c (set_tdesc_cmd, unset_tdesc_cmd): Pass
all_commands, not -1, to help_list.
* symfile.c (overlay_command): Pass all_commands, not -1, to
help_list.
* spu-tdep.c (info_spu_command): Pass all_commands, not -1, to
help_list.
* serial.c (serial_set_cmd): Pass all_commands, not -1, to
help_list.
* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Pass all_commands, not
-1, to help_list.
* remote.c (remote_command, set_remote_cmd): Pass all_commands,
not -1, to help_list.
* ravenscar-thread.c (set_ravenscar_command): Pass all_commands,
not -1, to help_list.
* maint.c (maintenance_command, maintenance_info_command)
(maintenance_print_command, maintenance_set_cmd): Pass
all_commands, not -1, to help_list.
* macrocmd.c (macro_command): Pass all_commands, not -1, to
help_list.
* language.c (set_check): Pass all_commands, not -1, to help_list.
* infcmd.c (unset_command): Pass all_commands, not -1, to
help_list.
* frame.c (set_backtrace_cmd): Pass all_commands, not -1, to
help_list.
* dwarf2read.c (set_dwarf2_cmd): Pass all_commands, not -1, to
help_list.
* dcache.c (set_dcache_command): Pass all_commands, not -1, to
help_list.
* breakpoint.c (save_command): Pass all_commands, not -1, to
help_list.
* ada-lang.c (maint_set_ada_cmd, set_ada_command): Pass
all_commands, not -1, to help_list.
