notmuch-new: Only install SIGALRM if not running under gdb

I felt sorry for Carl trying to step through an exception from xapian
and suffering from the SIGALARMs..

We can detect if the user launched notmuch under a debugger by either
checking our cmdline for the presence of the gdb string or querying if
valgrind is controlling our process. For the latter we need to add a
compile time check for the valgrind development library, and so add the
initial support to build Makefile.config from configure.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Carl Worth <cworth@cworth.org>
[ickle: And do not install the timer when under the debugger]

1 files changed, 47 insertions, 0 deletions

diff --git a/debugger.c b/debugger.c
new file mode 100644
index 00000000..e8b9378e
--- /dev/null
+++ b/debugger.c
@@ -0,0 +1,47 @@
+/* debugger.c - Some debugger utilities for the notmuch mail library
+ *
+ * Copyright © 2009 Chris Wilson
+ *
+ * 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/ .
+ *
+ * Author: Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#include "notmuch-client.h"
+
+#include <libgen.h>
+
+#if HAVE_VALGRIND
+#include <valgrind.h>
+#else
+#define RUNNING_ON_VALGRIND 0
+#endif
+
+notmuch_bool_t
+debugger_is_active (void)
+{
+    char buf[1024];
+
+    if (RUNNING_ON_VALGRIND)
+	return TRUE;
+
+    sprintf (buf, "/proc/%d/exe", getppid ());
+    if (readlink (buf, buf, sizeof (buf)) != -1 &&
+	strncmp (basename (buf), "gdb", 3) == 0)
+    {
+	return TRUE;
+    }
+
+    return FALSE;
+}