From be238512cce3d1fb6555ee470cf8258786c83d9c Mon Sep 17 00:00:00 2001
From: Julien Danjou <julien@danjou.info>
Date: Fri, 5 Jun 2009 12:18:16 +0200
Subject: [PATCH] awesome: dump backtrace on SEGV/ABRT

Signed-off-by: Julien Danjou <julien@danjou.info>
---
 CMakeLists.txt     |  1 +
 awesome.c          | 10 +++++++++
 common/backtrace.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++
 common/backtrace.h | 31 ++++++++++++++++++++++++++
 4 files changed, 97 insertions(+)
 create mode 100644 common/backtrace.c
 create mode 100644 common/backtrace.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5c74fe0f5..d0e84ef05 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -73,6 +73,7 @@ set(AWE_SRCS
     ${SOURCE_DIR}/common/xembed.c
     ${SOURCE_DIR}/common/xutil.c
     ${SOURCE_DIR}/common/xcursor.c
+    ${SOURCE_DIR}/common/backtrace.c
     ${SOURCE_DIR}/widgets/graph.c
     ${SOURCE_DIR}/widgets/progressbar.c
     ${SOURCE_DIR}/widgets/textbox.c
diff --git a/awesome.c b/awesome.c
index 4e0775f80..fd8ecd70f 100644
--- a/awesome.c
+++ b/awesome.c
@@ -46,6 +46,7 @@
 #include "common/atoms.h"
 #include "common/xcursor.h"
 #include "common/xutil.h"
+#include "common/backtrace.h"
 
 awesome_t globalconf;
 
@@ -234,6 +235,14 @@ xerrorstart(void * data __attribute__ ((unused)),
     fatal("another window manager is already running");
 }
 
+static void
+signal_fatal(EV_P_ ev_signal *w, int revents)
+{
+    buffer_t buf;
+    backtrace_get(&buf);
+    fatal("dumping backtrace\n%s", buf.s);
+}
+
 /** Function to exit on some signals.
  * \param sig the signal received, unused
  */
@@ -399,6 +408,7 @@ main(int argc, char **argv)
     ev_signal_init(&sigint, exit_on_signal, SIGINT);
     ev_signal_init(&sigterm, exit_on_signal, SIGTERM);
     ev_signal_init(&sighup, restart_on_signal, SIGHUP);
+    ev_signal_init(&sighup, signal_fatal, SIGSEGV);
     ev_signal_start(globalconf.loop, &sigint);
     ev_signal_start(globalconf.loop, &sigterm);
     ev_signal_start(globalconf.loop, &sighup);
diff --git a/common/backtrace.c b/common/backtrace.c
new file mode 100644
index 000000000..96a8f0e07
--- /dev/null
+++ b/common/backtrace.c
@@ -0,0 +1,55 @@
+/*
+ * common/backtrace.c - Backtrace handling functions
+ *
+ * Copyright © 2009 Julien Danjou <julien@danjou.info>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <execinfo.h>
+#include "common/backtrace.h"
+
+#define MAX_STACK_SIZE 32
+
+/** Get a backtrace.
+  * \param buf The buffer to fill with backtrace.
+  */
+void
+backtrace_get(buffer_t *buf)
+{
+    void *stack[MAX_STACK_SIZE];
+    char **bt;
+    int stack_size;
+
+    stack_size = backtrace(stack, countof(stack));
+    bt = backtrace_symbols(stack, stack_size);
+
+    buffer_init(buf);
+    if(bt)
+    {
+        for(int i = 0; i < stack_size; i++)
+        {
+            if(i > 0)
+                buffer_addsl(buf, "\n");
+            buffer_adds(buf, bt[i]);
+        }
+        p_delete(&bt);
+    }
+    else
+        buffer_addsl(buf, "Cannot get backtrace symbols.");
+}
+
+// vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80
diff --git a/common/backtrace.h b/common/backtrace.h
new file mode 100644
index 000000000..25a3e1e95
--- /dev/null
+++ b/common/backtrace.h
@@ -0,0 +1,31 @@
+/*
+ * common/backtrace.h - Backtrace handling
+ *
+ * Copyright © 2009 Julien Danjou <julien@danjou.info>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef AWESOME_COMMON_BACKTRACE
+#define AWESOME_COMMON_BACKTRACE
+
+#include "common/buffer.h"
+
+void backtrace_get(buffer_t *);
+
+#endif
+
+// vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80