+2009-04-01 Pedro Alves <pedro@codesourcery.com>
+
+ * linux-low.c (linux_wait_for_event): Don't clear the `stepping'
+ flag.
+ (wait_for_sigstop): Don't leave a finished single-step SIGTRAP
+ pending.
+ (linux_continue_one_thread): Only preserve the stepping flag if
+ there's a pending breakpoint.
+
2009-03-31 Pedro Alves <pedro@codesourcery.com>
* server.c (main): After the inferior having exited, call
static int check_removed_breakpoint (struct lwp_info *event_child);
static void *add_lwp (unsigned long pid);
static int my_waitpid (int pid, int *status, int flags);
+static int linux_stopped_by_watchpoint (void);
struct pending_signals
{
fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
/* If we were single-stepping, we definitely want to report the
- SIGTRAP. The single-step operation has completed, so also
- clear the stepping flag; in general this does not matter,
- because the SIGTRAP will be reported to the client, which
- will give us a new action for this thread, but clear it for
- consistency anyway. It's safe to clear the stepping flag
- because the only consumer of get_stop_pc () after this point
- is check_removed_breakpoint, and pending_is_breakpoint is not
- set. It might be wiser to use a step_completed flag instead. */
+ SIGTRAP. Although the single-step operation has completed,
+ do not clear clear the stepping flag yet; we need to check it
+ in wait_for_sigstop. */
if (event_child->stepping)
- {
- event_child->stepping = 0;
- return wstat;
- }
+ return wstat;
/* A SIGTRAP that we can't explain. It may have been a breakpoint.
Check if it is a breakpoint, and if so mark the process information
if (debug_threads)
fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
lwp->lwpid, wstat);
- lwp->status_pending_p = 1;
- lwp->status_pending = wstat;
+
+ /* Do not leave a pending single-step finish to be reported to
+ the client. The client will give us a new action for this
+ thread, possibly a continue request --- otherwise, the client
+ would consider this pending SIGTRAP reported later a spurious
+ signal. */
+ if (WSTOPSIG (wstat) == SIGTRAP
+ && lwp->stepping
+ && !linux_stopped_by_watchpoint ())
+ {
+ if (debug_threads)
+ fprintf (stderr, " single-step SIGTRAP ignored\n");
+ }
+ else
+ {
+ lwp->status_pending_p = 1;
+ lwp->status_pending = wstat;
+ }
lwp->stop_expected = 1;
}
if (lwp->resume->leave_stopped)
return;
- if (lwp->resume->thread == -1)
- step = lwp->stepping || lwp->resume->step;
+ if (lwp->resume->thread == -1
+ && lwp->stepping
+ && lwp->pending_is_breakpoint)
+ step = 1;
else
step = lwp->resume->step;
+2009-04-01 Pedro Alves <pedro@codesourcery.com>
+
+ * gdb.threads/pending-step.c, gdb.threads/pending-step.exp: New.
+
2009-04-01 Tom Tromey <tromey@redhat.com>
* gdb.base/funcargs.exp: Set print frame-arguments to "all".
--- /dev/null
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2002, 2003, 2004, 2007, 2008, 2009 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+void *thread_function(void *arg); /* Pointer to function executed by each thread */
+
+#define NUM 1
+
+unsigned int args[NUM+1];
+
+int main() {
+ int res;
+ pthread_t threads[NUM];
+ void *thread_result;
+ long i;
+
+ for (i = 1; i <= NUM; i++)
+ {
+ args[i] = 1;
+ res = pthread_create(&threads[i],
+ NULL,
+ thread_function,
+ (void *) i);
+ }
+
+ /* schedlock.exp: last thread start. */
+ args[0] = 1;
+ thread_function ((void *) 0);
+
+ exit(EXIT_SUCCESS);
+}
+
+void *thread_function(void *arg) {
+ int my_number = (long) arg;
+ int *myp = (int *) &args[my_number];
+
+ /* Don't run forever. Run just short of it :) */
+ while (*myp > 0)
+ {
+ (*myp) ++; /* insert breakpoint here */
+ }
+
+ pthread_exit(NULL);
+}
--- /dev/null
+# Copyright (C) 2009 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Test that a resume cancels a previously unfinished or unreported
+# single-step correctly.
+#
+# The test consists of several threads all running the same loop.
+# There is a breakpoint set in the loop, hence all threads may hit it.
+# The test then issues several "next" commands in a loop.
+#
+# scheduler-locking must be set to the default of "off".
+#
+# Here's what would happen in gdbserver:
+#
+# 1) We issue a "continue", and wait until a thread hits the
+# breakpoint. Could be any thread, but assume thread 1 hits it.
+#
+# 2) We issue a "next" --- this single-steps thread 1, and resumes all
+# other threads.
+#
+# 3) thread 2, due to scheduler-locking off, hits the breakpoint.
+# gdbserver stops all other threads by sending them SIGSTOPs.
+#
+# 4) While being stopped in step 3, thread 1 reports a SIGTRAP, that
+# corresponds to the finished single-step of step 2. gdbserver
+# leaves the SIGTRAP pending to report later.
+#
+# 5) We issue another "next" --- this requests thread 2 to
+# single-step, and all other threads to continue, including thread
+# 1. Before resuming any thread, gdbserver notices that it
+# remembers from step 4 a pending SIGTRAP to report for thread 1,
+# so reports it now.
+#
+# 6) From GDB's perpective, this SIGTRAP can't represent a finished
+# single-step, since thread 1 was not single-stepping (it was
+# continued in step 5). Neither does this SIGTRAP correspond to a
+# breakpoint hit. GDB reports to the user a spurious SIGTRAP.
+
+set testfile "pending-step"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "incdir=${objdir}"]] != "" } {
+ return -1
+}
+
+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if ![runto_main] then {
+ fail "Can't run to main"
+ return 0
+}
+
+gdb_breakpoint [gdb_get_line_number "insert breakpoint here"]
+gdb_continue_to_breakpoint "continue to first breakpoint hit"
+
+set test "next in multiple threads with breakpoints"
+set iterations 20
+set ok 0
+for {set i 0} {$i < $iterations} {incr i} {
+ set ok 0
+ gdb_test_multiple "next" "$test" {
+ -re "SIGTRAP.*$gdb_prompt $" {
+ fail "$test (spurious SIGTRAP)"
+ }
+ -re "$gdb_prompt $" {
+ set ok 1
+ }
+ }
+
+ if { $ok == 0 } {
+ break
+ }
+}
+
+if { $ok } {
+ pass "$test"
+}
projects / binutils-gdb.git / commitdiff