2005-02-11 Jeff Johnston <jjohnstn@redhat.com>
* target.h (target_waitstatus): Add new step_thread_exit flag.
* infrun.c (init_execution_control_state): Initialize step_thread_exit.
(handle_inferior_event): If step_thread_exit flag is set, print
out special message and reset flag.
(currently_stepping): Do not return true if step_thread_exit flag
is set.
* linux-nat.c (resume_callback): Use second parameter to notify
if the resume should be a PTRACE_SINGLESTEP or PTRACE_CONT.
(stop_and_resume_callback): Pass on data parameter to resume_callback.
(linux_nat_resume): Don't attempt to resume if lp is NULL.
(linux_nat_wait): Do not wait on step_lp as first wait. After
wait, check if step_lp has an event or not. If the step lwp has
exited, issue a stop on the first non-step_lp lwp in the lwp list.
Change the delayed stop code to not ignore an intentional stop.
If we see an event on an lwp which isn't the step_lp, verify if
the step_lp has exited or not. Set the step_thread_exit flag if
we have verified that the step_lp is gone.
* testsuite/gdb.threads/step-thread-exit.c: New testcase.
* testsuite/gdb.threads/step-thread-exit.exp: Ditto.
Index: gdb-6.5/gdb/testsuite/gdb.threads/step-thread-exit.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-6.5/gdb/testsuite/gdb.threads/step-thread-exit.c 2006-07-07 02:26:54.000000000 -0300
@@ -0,0 +1,43 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2005 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 2 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, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+void *thread_function (void *ptr)
+{
+ int *x = (int *)ptr;
+ printf("In thread_function, *x is %d\n", *x);
+} /* thread_function_end */
+
+main()
+{
+ int ret;
+ pthread_t th;
+ int i = 3;
+
+ ret = pthread_create (&th, NULL, thread_function, &i);
+ pthread_join (th, NULL);
+ sleep (3); /* sleep */
+ return 0;
+}
+
+
Index: gdb-6.5/gdb/testsuite/gdb.threads/step-thread-exit.exp
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-6.5/gdb/testsuite/gdb.threads/step-thread-exit.exp 2006-07-07 02:26:54.000000000 -0300
@@ -0,0 +1,100 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2005 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 2 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+# Check that GDB can step over a thread exit.
+
+if $tracelevel {
+ strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile "step-thread-exit"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "incdir=${objdir}"]] != "" } {
+ return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+# Reset the debug file directory so we can't debug within the C library
+gdb_test "set debug-file-directory ." "" ""
+
+#
+# Run to `main' where we begin our tests.
+#
+
+if ![runto_main] then {
+ gdb_suppress_tests
+}
+
+set sleep_line [expr [gdb_get_line_number "sleep"]]
+set end_line [expr [gdb_get_line_number "thread_function_end"]]
+
+gdb_breakpoint "$end_line"
+gdb_test "continue" "Break.*thread_function.*" "continue to thread_function 1"
+
+# Keep nexting until we cause the thread to exit. We expect the main
+# thread to be stopped and a message printed to tell us we have stepped
+# over the thread exit.
+set test "step over thread exit 1"
+gdb_test_multiple "next" "$test" {
+ -re "\}.*$gdb_prompt $" {
+ send_gdb "next\n"
+ exp_continue
+ }
+ -re "Thread.*exited.*Stepped over thread exit.*Program received signal SIGSTOP.*$gdb_prompt $" {
+ pass $test
+ }
+ -re "start_thread.*$gdb_prompt $" {
+ send_gdb "next\n"
+ exp_continue
+ }
+}
+
+gdb_test "bt" ".*sleep.*main.*$sleep_line.*" "backtrace after step 1"
+
+runto_main
+gdb_breakpoint "$sleep_line"
+gdb_breakpoint "$end_line"
+gdb_test "continue" "Break.*thread_function.*" "continue to thread_function 2"
+
+# Keep nexting until we cause the thread to exit. In this case, we
+# expect the breakpoint in the main thread to have already triggered
+# and so we should stop there with a message that we stepped over
+# the thread exit.
+set test "step over thread exit 2"
+gdb_test_multiple "next" "$test" {
+ -re "\}.*$gdb_prompt $" {
+ send_gdb "next\n"
+ exp_continue
+ }
+ -re "Thread.*exited.*Stepped over thread exit.*Break.*$sleep_line.*" {
+ pass $test
+ }
+ -re "start_thread.*$gdb_prompt $" {
+ send_gdb "next\n"
+ exp_continue
+ }
+}
+
Index: gdb-6.5/gdb/infrun.c
===================================================================
--- gdb-6.5.orig/gdb/infrun.c 2006-07-07 01:17:35.000000000 -0300
+++ gdb-6.5/gdb/infrun.c 2006-07-07 02:26:54.000000000 -0300
@@ -1088,6 +1088,7 @@ init_execution_control_state (struct exe
ecs->current_symtab = ecs->sal.symtab;
ecs->infwait_state = infwait_normal_state;
ecs->waiton_ptid = pid_to_ptid (-1);
+ ecs->ws.step_thread_exit = 0;
ecs->wp = &(ecs->ws);
}
@@ -1307,6 +1308,16 @@ handle_inferior_event (struct execution_
ui_out_text (uiout, "]\n");
}
+ /* Check if were stepping a thread and we stepped over the exit.
+ In such a case, we will have found another event to process.
+ Clear any stepping state and process that event. */
+ if (ecs->ws.step_thread_exit)
+ {
+ printf_unfiltered ("[Stepped over thread exit]\n");
+ clear_proceed_status ();
+ ecs->ws.step_thread_exit = 0;
+ }
+
switch (ecs->ws.kind)
{
case TARGET_WAITKIND_LOADED:
@@ -2651,11 +2662,12 @@ process_event_stop_test:
static int
currently_stepping (struct execution_control_state *ecs)
{
- return ((!ecs->handling_longjmp
- && ((step_range_end && step_resume_breakpoint == NULL)
- || trap_expected))
- || ecs->stepping_through_solib_after_catch
- || bpstat_should_step ());
+ return (!ecs->ws.step_thread_exit
+ && ((!ecs->handling_longjmp
+ && ((step_range_end && step_resume_breakpoint == NULL)
+ || trap_expected))
+ || ecs->stepping_through_solib_after_catch
+ || bpstat_should_step ()));
}
/* Subroutine call with source code we should not step over. Do step
Index: gdb-6.5/gdb/linux-nat.c
===================================================================
--- gdb-6.5.orig/gdb/linux-nat.c 2006-07-07 02:24:51.000000000 -0300
+++ gdb-6.5/gdb/linux-nat.c 2006-07-07 02:29:12.000000000 -0300
@@ -1121,18 +1121,21 @@ linux_nat_detach (char *args, int from_t
static int
resume_callback (struct lwp_info *lp, void *data)
{
+ int step = (data != NULL);
+
if (lp->stopped && lp->status == 0)
{
struct thread_info *tp;
linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)),
- 0, TARGET_SIGNAL_0);
+ step, TARGET_SIGNAL_0);
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
- "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
+ "RC: %s %s, 0, 0 (resume sibling)\n",
+ step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
target_pid_to_str (lp->ptid));
lp->stopped = 0;
- lp->step = 0;
+ lp->step = step;
}
return 0;
@@ -1243,13 +1246,17 @@ linux_nat_resume (ptid_t ptid, int step,
if (resume_all)
iterate_over_lwps (resume_callback, NULL);
- linux_ops->to_resume (ptid, step, signo);
- if (debug_linux_nat)
- fprintf_unfiltered (gdb_stdlog,
- "LLR: %s %s, %s (resume event thread)\n",
- step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
- target_pid_to_str (ptid),
- signo ? strsignal (signo) : "0");
+ if (lp)
+ {
+ linux_ops->to_resume (ptid, step, signo);
+
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLR: %s %s, %s (resume event thread)\n",
+ step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
+ target_pid_to_str (ptid),
+ signo ? strsignal (signo) : "0");
+ }
}
/* Issue kill to specified lwp. */
@@ -1840,7 +1847,7 @@ stop_and_resume_callback (struct lwp_inf
for (ptr = lwp_list; ptr; ptr = ptr->next)
if (lp == ptr)
{
- resume_callback (lp, NULL);
+ resume_callback (lp, data);
resume_set_callback (lp, NULL);
}
}
@@ -1851,8 +1858,10 @@ static ptid_t
linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
{
struct lwp_info *lp = NULL;
+ struct lwp_info *step_lp = NULL;
int options = 0;
int status = 0;
+ int intentional_stop = 0;
pid_t pid = PIDGET (ptid);
sigset_t flush_mask;
@@ -1890,14 +1899,12 @@ retry:
gets the expected trap so we don't want to wait on any LWP.
This has ramifications when adjustment of the PC is required which can be
different after a breakpoint vs a step (e.g. x86). */
- lp = iterate_over_lwps (find_singlestep_lwp_callback, NULL);
- if (lp) {
+ step_lp = iterate_over_lwps (find_singlestep_lwp_callback, NULL);
+ if (step_lp) {
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
"LLW: Found step lwp %s.\n",
- target_pid_to_str (lp->ptid));
- ptid = lp->ptid;
- pid = PIDGET (ptid);
+ target_pid_to_str (step_lp->ptid));
}
/* If any pid, check if there is a LWP with a wait status pending. */
@@ -2130,8 +2137,9 @@ retry:
}
/* Make sure we don't report a SIGSTOP that we sent
- ourselves in an attempt to stop an LWP. */
- if (lp->signalled
+ ourselves in an attempt to stop an LWP, unless we
+ intentionally want to see the SIGSTOP. */
+ if (lp->signalled && !intentional_stop
&& WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
{
if (debug_linux_nat)
@@ -2165,6 +2173,20 @@ retry:
if (pid == -1)
{
+ lp = NULL;
+ if (step_lp && errno == ECHILD)
+ {
+ /* We have stepped over a thread exit. We want to stop
+ the first existing lwp we find and report a stop event. */
+ for (lp = lwp_list; lp && lp == step_lp; lp = lp->next)
+ ; /* empty */
+ }
+ if (lp != NULL)
+ {
+ stop_callback (lp, NULL);
+ intentional_stop = 1;
+ }
+
/* Alternate between checking cloned and uncloned processes. */
options ^= __WCLONE;
@@ -2237,6 +2259,42 @@ retry:
fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
status_to_str (status), target_pid_to_str (lp->ptid));
+ /* Check if there is any LWP that is being single-stepped. We need to
+ wait specifically on such an LWP because the higher-level code is
+ expecting a step operation to find an event on the stepped LWP.
+ It is possible for other events to occur before the step operation
+ gets the expected trap so we don't want to wait on any LWP.
+ This has ramifications when adjustment of the PC is required which can be
+ different after a breakpoint vs a step (e.g. x86). */
+ if (step_lp && step_lp != lp)
+ {
+ struct lwp_info *ptr;
+ int arg = 1;
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: Found step lwp %s.\n",
+ target_pid_to_str (step_lp->ptid));
+ stop_and_resume_callback (step_lp, &arg);
+ for (ptr = lwp_list; ptr; ptr = ptr->next)
+ if (step_lp == ptr)
+ break;
+
+ if (ptr)
+ {
+ if (debug_linux_nat)
+ fprintf_unfiltered (gdb_stdlog,
+ "LLW: Continuing step lwp %s.\n",
+ target_pid_to_str (step_lp->ptid));
+ ptid = step_lp->ptid;
+ pid = PIDGET (ptid);
+ lp->status = status;
+ status = 0;
+ options = WNOHANG | (step_lp->cloned ? __WCLONE : 0);
+ pid = GET_LWP (ptid);
+ goto retry;
+ }
+ }
+
/* Now stop all other LWP's ... */
iterate_over_lwps (stop_callback, NULL);
@@ -2275,6 +2333,10 @@ retry:
else
store_waitstatus (ourstatus, status);
+ /* If we were stepping a thread and it exited, mark this. */
+ if (step_lp && step_lp != lp)
+ ourstatus->step_thread_exit = 1;
+
return lp->ptid;
}
Index: gdb-6.5/gdb/target.h
===================================================================
--- gdb-6.5.orig/gdb/target.h 2006-05-05 17:08:45.000000000 -0300
+++ gdb-6.5/gdb/target.h 2006-07-07 02:26:54.000000000 -0300
@@ -136,6 +136,7 @@ enum target_waitkind
struct target_waitstatus
{
enum target_waitkind kind;
+ int step_thread_exit; /* non-zero if we step over a thread exit. */
/* Forked child pid, execd pathname, exit status or signal number. */
union