Re: [RFA] dummy frame handling cleanup, plus inferior fun call signal handling improvement

[Doug Evans <dje@google.com>]

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ref: http://sourceware.org/ml/gdb-patches/2008-11/msg00454.html

On Tue, Nov 18, 2008 at 4:58 AM, Doug Evans <dje@google.com> wrote:
> [...]
> There are two things this patch does:
> 1) properly pop dummy frames more often
> 2) make the inferior resumable after an inferior function call gets a
>   signal without having to remember to do "signal 0"
> [...]
> Restoring stop_signal also has the benefit that if an inferior function
> call is made after getting a signal, and the inferior function call
> doesn't complete (e.g. has a breakpoint and doesn't complete right away),
> the user can resume the program (after popping the inf fun call off the
> stack) with "continue" without having to remember what the signal was
> and remember to use "signal N".
> [...]

Hi.  This patch is an update to the testcases for this patch,
call-signal-resume.exp now tests for the above case.

Comments?

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2008-11-25  Doug Evans  <dje@google.com>

	* gdb.base/call-signal-resume.exp: New file.
	* gdb.base/call-signals.c: New file.
	* gdb.base/unwindonsignal.exp: New file.
	* gdb.base/unwindonsignal.c: New file.

Index: call-signal-resume.exp
===================================================================
RCS file: call-signal-resume.exp
diff -N call-signal-resume.exp
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ call-signal-resume.exp	26 Nov 2008 01:51:04 -0000
@@ -0,0 +1,157 @@
+# Copyright 2008 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 inferior resumption after discarding a hand-called function.
+# There are two things to test.
+# 1) Inferior stops normally.  Upon resumption it should continue normally,
+#    regardless of whatever signal the hand-called function got.
+# 2) Inferior is stopped at a signal.  Upon resumption it should continue
+#    with that signal, regardless of whatever the hand-called function did.
+
+if $tracelevel then {
+	strace $tracelevel
+}
+
+if [target_info exists gdb,noinferiorio] {
+    verbose "Skipping call-signal-resume.exp because of no fileio capabilities."
+    continue
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile "call-signals"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
+     untested call-signal-resume.exp
+     return -1
+}
+
+# Some targets can't do function calls, so don't even bother with this
+# test.
+if [target_info exists gdb,cannot_call_functions] {
+    setup_xfail "*-*-*" 2416
+    fail "This target can not call functions"
+    continue
+}
+
+proc get_dummy_frame_number { } {
+  global gdb_prompt
+
+  send_gdb "bt\n"
+  gdb_expect {
+    -re "#(\[0-9\]*) *<function called from gdb>.*$gdb_prompt $"
+      {
+	return $expect_out(1,string)
+      }
+    -re "$gdb_prompt $"
+      {
+	return ""
+      }
+    timeout
+      {
+	return ""
+      }
+  }
+  return ""
+}
+
+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if { ![runto_main] } {
+    fail "Can't run to main"
+    return 0
+}
+
+gdb_test "break stop_one" "Breakpoint \[0-9\]* at .*"
+gdb_test "continue" "Continuing.*Breakpoint \[0-9\]*, stop_one.*" \
+    "continue to breakpoint at stop_one"
+
+# Call function (causing the program to get a signal), and see if gdb handles
+# it properly.
+gdb_test_multiple "call gen_signal ()" \
+	"call-signal-resume, inferior function call signaled" {
+    -re "\[\r\n\]*no signal\[\r\n\]+$gdb_prompt $" {
+	unsupported "call-signal-resume, inferior function call signaled"
+	return 0
+    }
+    -re "\[\r\n\]*The program being debugged was signaled.*\[\r\n\]+$gdb_prompt $" {
+	pass "call-signal-resume, inferior function call signaled"
+    }
+}
+
+set frame_number [get_dummy_frame_number]
+if { "$frame_number" == "" } {
+    fail "call-signal-resume, dummy stack frame number"
+    setup_xfail "*-*-*"
+} else {
+    pass "call-signal-resume, dummy stack frame number"
+}
+
+# Pop the dummy frame.
+gdb_test "frame $frame_number" ""
+gdb_test "set confirm off" ""
+gdb_test "return" ""
+
+# Resume execution, the program should continue without any signal.
+
+gdb_test "break stop_two" "Breakpoint \[0-9\]* at .*"
+gdb_test "continue" "Breakpoint \[0-9\]*, stop_two.*" \
+    "continue to breakpoint at stop_two"
+
+# Continue again, we should get a signal.
+
+gdb_test "continue" "Program received signal .*" \
+    "continue to receipt of signal"
+
+# Hand call another function that prematurely stops,
+# then manually pop the dummy stack frame.
+
+gdb_test "break null_hand_call" "Breakpoint \[0-9\]* at .*"
+gdb_test "call null_hand_call ()" "Breakpoint \[0-9\]*, null_hand_call.*" \
+    "null_hand_call"
+
+set frame_number [get_dummy_frame_number]
+if { "$frame_number" == "" } {
+    fail "call-signal-resume, dummy stack frame number"
+    setup_xfail "*-*-*"
+} else {
+    pass "call-signal-resume, dummy stack frame number"
+}
+
+# Pop the dummy frame.
+gdb_test "frame $frame_number" ""
+gdb_test "set confirm off" ""
+gdb_test "return" ""
+
+# Continue again, this time we should get to the signal handler.
+
+gdb_test "break handle_signal" "Breakpoint \[0-9\]* at .*"
+gdb_test "continue" "Breakpoint \[0-9\]*, handle_signal.*" \
+    "continue to breakpoint at handle_signal"
+
+# Continue one last time, the program should exit normally.
+
+gdb_test "continue" "Program exited normally." \
+    "continue to program exit"
+
+return 0
Index: call-signals.c
===================================================================
RCS file: call-signals.c
diff -N call-signals.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ call-signals.c	26 Nov 2008 01:51:04 -0000
@@ -0,0 +1,89 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2008 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/>.  */
+
+/* Support program for testing handling of inferior function calls
+   in the presence of signals.  */
+
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+
+void
+handle_signal (int sig)
+{
+}
+
+void
+gen_signal ()
+{
+  /* According to sigall.exp, SIGABRT is always supported.  */
+#ifdef SIGABRT
+  kill (getpid (), SIGABRT);
+#endif
+  /* If we get here we couldn't generate a signal, tell dejagnu.  */
+  printf ("no signal\n");
+}
+
+/* Easy place to set a breakpoint.  */
+
+void
+stop_one ()
+{
+}
+
+void
+stop_two ()
+{
+}
+
+void
+null_hand_call ()
+{
+}
+
+int
+main ()
+{
+#ifdef usestubs
+  set_debug_traps ();
+  breakpoint ();
+#endif
+
+#ifdef SIG_SETMASK
+  /* Ensure all the signals aren't blocked.
+     The environment in which the testsuite is run may have blocked some
+     for whatever reason.  */
+  {
+    sigset_t newset;
+    sigemptyset (&newset);
+    sigprocmask (SIG_SETMASK, &newset, NULL);
+  }
+#endif
+
+  signal (SIGABRT, handle_signal);
+
+  /* Stop here so we can hand-call gen_signal.  */
+  stop_one ();
+
+  /* When we're resumed stop here.  */
+  stop_two ();
+
+  /* When we're resumed we generate a signal ourselves.  */
+  gen_signal ();
+
+  return 0;
+}
Index: unwindonsignal.c
===================================================================
RCS file: unwindonsignal.c
diff -N unwindonsignal.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ unwindonsignal.c	26 Nov 2008 01:51:04 -0000
@@ -0,0 +1,65 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2008 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/>.  */
+
+/* Support program for testing unwindonsignal.  */
+
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+
+void
+gen_signal ()
+{
+  /* According to sigall.exp, SIGABRT is always supported.  */
+#ifdef SIGABRT
+  kill (getpid (), SIGABRT);
+#endif
+  /* If we get here we couldn't generate a signal, tell dejagnu.  */
+  printf ("no signal\n");
+}
+
+/* Easy place to set a breakpoint.  */
+
+void
+stop_here ()
+{
+}
+
+int
+main ()
+{
+#ifdef usestubs
+  set_debug_traps ();
+  breakpoint ();
+#endif
+
+#ifdef SIG_SETMASK
+  /* Ensure all the signals aren't blocked.
+     The environment in which the testsuite is run may have blocked some
+     for whatever reason.  */
+  {
+    sigset_t newset;
+    sigemptyset (&newset);
+    sigprocmask (SIG_SETMASK, &newset, NULL);
+  }
+#endif
+
+  /* Stop here so we can hand-call gen_signal.  */
+  stop_here ();
+
+  return 0;
+}
Index: unwindonsignal.exp
===================================================================
RCS file: unwindonsignal.exp
diff -N unwindonsignal.exp
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ unwindonsignal.exp	26 Nov 2008 01:51:04 -0000
@@ -0,0 +1,98 @@
+# Copyright 2008 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/>.
+
+if $tracelevel then {
+	strace $tracelevel
+}
+
+if [target_info exists gdb,noinferiorio] {
+    verbose "Skipping unwindonsignal.exp because of no fileio capabilities."
+    continue
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile "unwindonsignal"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
+     untested unwindonsignal.exp
+     return -1
+}
+
+# Some targets can't do function calls, so don't even bother with this
+# test.
+if [target_info exists gdb,cannot_call_functions] {
+    setup_xfail "*-*-*" 2416
+    fail "This target can not call functions"
+    continue
+}
+
+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if { ![runto_main] } {
+    fail "Can't run to main"
+    return 0
+}
+
+gdb_test "break stop_here" "Breakpoint \[0-9\]* at .*"
+gdb_test "continue" "Continuing.*Breakpoint \[0-9\]*, stop_here.*" \
+    "continue to breakpoint at stop_here"
+
+# Turn on unwindonsignal.
+gdb_test "set unwindonsignal on" \
+	"" \
+	"setting unwindonsignal"
+gdb_test "show unwindonsignal" \
+	"Unwinding of stack .* is on." \
+	"showing unwindonsignal"
+
+# Call function (causing the program to get a signal), and see if gdb handles
+# it properly.
+gdb_test_multiple "call gen_signal ()" \
+	"unwindonsignal, inferior function call signaled" {
+    -re "\[\r\n\]*no signal\[\r\n\]+$gdb_prompt $" {
+	unsupported "unwindonsignal, inferior function call signaled"
+	return 0
+    }
+    -re "\[\r\n\]*The program being debugged was signaled.*\[\r\n\]+$gdb_prompt $" {
+	pass "unwindonsignal, inferior function call signaled"
+    }
+}
+
+# Verify the stack got unwound.
+gdb_test "bt" \
+    "#0 *\[x0-9a-f in\]*stop_here \\(.*\\) at .*#1 *\[x0-9a-f in\]*main \\(.*\\) at .*" \
+	"unwindonsignal, stack unwound"
+
+# Verify the dummy frame got removed from dummy_frame_stack.
+gdb_test_multiple "maint print dummy-frames" \
+	"unwindonsignal, dummy frame removed" {
+    -re "\[\r\n\]*.*stack=.*code=.*\[\r\n\]+$gdb_prompt $" {
+	fail "unwindonsignal, dummy frame removed"
+    }
+    -re "\[\r\n\]+$gdb_prompt $" {
+	pass "unwindonsignal, dummy frame removed"
+    }
+}
+
+return 0