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]

Makefile.config

@@ -1,2 +1,3 @@
 prefix = /usr/local
 bash_completion_dir = /etc/bash_completion.d
+CFLAGS += -DHAVE_VALGRIND

Makefile.local

@@ -3,6 +3,8 @@ all: notmuch notmuch.1.gz
 emacs: notmuch.elc
 
 notmuch_client_srcs =		\
+	debugger.c		\
+	gmime-filter-reply.c	\
 	notmuch.c		\
 	notmuch-config.c	\
 	notmuch-dump.c		\
@@ -14,7 +16,6 @@ notmuch_client_srcs =		\
 	notmuch-show.c		\
 	notmuch-tag.c		\
 	notmuch-time.c		\
-	gmime-filter-reply.c	\
 	query-string.c		\
 	show-message.c
 

configure

@@ -53,6 +53,14 @@ else
     errors=$((errors + 1))
 fi
 
+if pkg-config --modversion valgrind > /dev/null 2>&1; then
+    echo "Checking for valgrind development files... Yes."
+    have_valgrind=-DHAVE_VALGRIND
+else
+    echo "Checking for valgrind development files... No."
+    have_valgrind=
+fi
+
 if [ $errors -gt 0 ]; then
     cat <<EOF
 
@@ -108,7 +116,8 @@ configure again to ensure the packages can be found, or simply run
 
 EOF
     exit 1
-else
+fi
+
 cat <<EOF
 
 All required packages were found. You may now run the following
@@ -118,6 +127,10 @@ commands to compile and install notmuch:
 	sudo make install
 
 EOF
-    exit 0
-fi
-cat <<EOF
+
+# construct the Makefile.config
+cat > Makefile.config <<EOF
+prefix = /usr/local
+bash_completion_dir = /etc/bash_completion.d
+CFLAGS += ${have_valgrind}
+EOF

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;
+}

notmuch-client.h

@@ -179,4 +179,7 @@ notmuch_config_set_user_other_email (notmuch_config_t *config,
 				     const char *other_email[],
 				     size_t length);
 
+notmuch_bool_t
+debugger_is_active (void);
+
 #endif

notmuch-new.c

@@ -259,6 +259,7 @@ add_files (notmuch_database_t *notmuch,
     notmuch_status_t status;
     struct sigaction action;
     struct itimerval timerval;
+    notmuch_bool_t timer_is_active = FALSE;
 
     if (stat (path, &st)) {
 	fprintf (stderr, "Error reading directory %s: %s\n",
@@ -272,31 +273,37 @@ add_files (notmuch_database_t *notmuch,
     }
 
     /* Setup our handler for SIGALRM */
-    memset (&action, 0, sizeof (struct sigaction));
-    action.sa_handler = handle_sigalrm;
-    sigemptyset (&action.sa_mask);
-    action.sa_flags = SA_RESTART;
-    sigaction (SIGALRM, &action, NULL);
+    if (! debugger_is_active ()) {
+	memset (&action, 0, sizeof (struct sigaction));
+	action.sa_handler = handle_sigalrm;
+	sigemptyset (&action.sa_mask);
+	action.sa_flags = SA_RESTART;
+	sigaction (SIGALRM, &action, NULL);
 
-    /* Then start a timer to send SIGALRM once per second. */
-    timerval.it_interval.tv_sec = 1;
-    timerval.it_interval.tv_usec = 0;
-    timerval.it_value.tv_sec = 1;
-    timerval.it_value.tv_usec = 0;
-    setitimer (ITIMER_REAL, &timerval, NULL);
+	/* Then start a timer to send SIGALRM once per second. */
+	timerval.it_interval.tv_sec = 1;
+	timerval.it_interval.tv_usec = 0;
+	timerval.it_value.tv_sec = 1;
+	timerval.it_value.tv_usec = 0;
+	setitimer (ITIMER_REAL, &timerval, NULL);
+
+	timer_is_active = TRUE;
+    }
 
     status = add_files_recursive (notmuch, path, &st, state);
 
     /* Now stop the timer. */
-    timerval.it_interval.tv_sec = 0;
-    timerval.it_interval.tv_usec = 0;
-    timerval.it_value.tv_sec = 0;
-    timerval.it_value.tv_usec = 0;
-    setitimer (ITIMER_REAL, &timerval, NULL);
+    if (timer_is_active) {
+	timerval.it_interval.tv_sec = 0;
+	timerval.it_interval.tv_usec = 0;
+	timerval.it_value.tv_sec = 0;
+	timerval.it_value.tv_usec = 0;
+	setitimer (ITIMER_REAL, &timerval, NULL);
 
-    /* And disable the signal handler. */
-    action.sa_handler = SIG_IGN;
-    sigaction (SIGALRM, &action, NULL);
+	/* And disable the signal handler. */
+	action.sa_handler = SIG_IGN;
+	sigaction (SIGALRM, &action, NULL);
+    }
 
     return status;
 }