diff --git a/Makefile.local b/Makefile.local
index a602ed08..66ccd6d1 100644
--- a/Makefile.local
+++ b/Makefile.local
@@ -249,7 +249,8 @@ notmuch_client_srcs =		\
 	notmuch-time.c		\
 	query-string.c		\
 	show-message.c		\
-	json.c
+	json.c			\
+	xutil.c
 
 notmuch_client_modules = $(notmuch_client_srcs:.c=.o)
 
diff --git a/lib/database-private.h b/lib/database-private.h
index bd72f670..e42b8bb8 100644
--- a/lib/database-private.h
+++ b/lib/database-private.h
@@ -34,6 +34,8 @@
 
 #include <xapian.h>
 
+#pragma GCC visibility push(hidden)
+
 struct _notmuch_database {
     notmuch_bool_t exception_reported;
 
@@ -65,4 +67,6 @@ notmuch_tags_t *
 _notmuch_convert_tags (void *ctx, Xapian::TermIterator &i,
 		       Xapian::TermIterator &end);
 
+#pragma GCC visibility pop
+
 #endif
diff --git a/lib/libsha1.h b/lib/libsha1.h
index b4dca93b..c1c848fc 100644
--- a/lib/libsha1.h
+++ b/lib/libsha1.h
@@ -43,6 +43,8 @@ extern "C"
 
 #include <stdint.h>
 
+#pragma GCC visibility push(hidden)
+
 /* Size of SHA1 digest */
 
 #define SHA1_DIGEST_SIZE 20
@@ -60,6 +62,8 @@ void sha1_hash(const unsigned char data[], unsigned long len, sha1_ctx ctx[1]);
 void sha1_end(unsigned char hval[], sha1_ctx ctx[1]);
 void sha1(unsigned char hval[], const unsigned char data[], unsigned long len);
 
+#pragma GCC visibility pop
+
 #if defined(__cplusplus)
 }
 #endif
diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 5a0cf925..5b32f84a 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -48,6 +48,8 @@ NOTMUCH_BEGIN_DECLS
 
 #include "xutil.h"
 
+#pragma GCC visibility push(hidden)
+
 #ifdef DEBUG
 # define DEBUG_DATABASE_SANITY 1
 # define DEBUG_QUERY 1
@@ -442,6 +444,8 @@ _notmuch_tags_add_tag (notmuch_tags_t *tags, const char *tag);
 void
 _notmuch_tags_prepare_iterator (notmuch_tags_t *tags);
 
+#pragma GCC visibility pop
+
 NOTMUCH_END_DECLS
 
 #endif
diff --git a/lib/xutil.h b/lib/xutil.h
index b973f7dc..fd77f733 100644
--- a/lib/xutil.h
+++ b/lib/xutil.h
@@ -25,6 +25,8 @@
 #include <sys/types.h>
 #include <regex.h>
 
+#pragma GCC visibility push(hidden)
+
 /* xutil.c */
 void *
 xcalloc (size_t nmemb, size_t size);
@@ -48,4 +50,6 @@ int
 xregexec (const regex_t *preg, const char *string,
 	  size_t nmatch, regmatch_t pmatch[], int eflags);
 
+#pragma GCC visibility pop
+
 #endif
diff --git a/xutil.c b/xutil.c
new file mode 100644
index 00000000..5f98f3f7
--- /dev/null
+++ b/xutil.c
@@ -0,0 +1,138 @@
+/* xutil.c - Various wrapper functions to abort on error.
+ *
+ * Copyright © 2009 Carl Worth
+ *
+ * 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: Carl Worth <cworth@cworth.org>
+ */
+
+#include "notmuch-private.h"
+
+#include <stdio.h>
+
+void *
+xcalloc (size_t nmemb, size_t size)
+{
+    void *ret;
+
+    ret = calloc (nmemb, size);
+    if (ret == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	exit (1);
+    }
+
+    return ret;
+}
+
+void *
+xmalloc (size_t size)
+{
+    void *ret;
+
+    ret = malloc (size);
+    if (ret == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	exit (1);
+    }
+
+    return ret;
+}
+
+void *
+xrealloc (void *ptr, size_t size)
+{
+    void *ret;
+
+    ret = realloc (ptr, size);
+    if (ret == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	exit (1);
+    }
+
+    return ret;
+}
+
+char *
+xstrdup (const char *s)
+{
+    char *ret;
+
+    ret = strdup (s);
+    if (ret == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	exit (1);
+    }
+
+    return ret;
+}
+
+char *
+xstrndup (const char *s, size_t n)
+{
+    char *ret;
+
+    if (strlen (s) <= n)
+	n = strlen (s);
+
+    ret = malloc (n + 1);
+    if (ret == NULL) {
+	fprintf (stderr, "Out of memory.\n");
+	exit (1);
+    }
+    memcpy (ret, s, n);
+    ret[n] = '\0';
+
+    return ret;
+}
+
+void
+xregcomp (regex_t *preg, const char *regex, int cflags)
+{
+    int rerr;
+
+    rerr = regcomp (preg, regex, cflags);
+    if (rerr) {
+	size_t error_size = regerror (rerr, preg, NULL, 0);
+	char *error = xmalloc (error_size);
+
+	regerror (rerr, preg, error, error_size);
+	fprintf (stderr, "Internal error: compiling regex %s: %s\n",
+		 regex, error);
+	exit (1);
+    }
+}
+
+int
+xregexec (const regex_t *preg, const char *string,
+	  size_t nmatch, regmatch_t pmatch[], int eflags)
+{
+    unsigned int i;
+    int rerr;
+
+    rerr = regexec (preg, string, nmatch, pmatch, eflags);
+    if (rerr)
+	return rerr;
+
+    for (i = 0; i < nmatch; i++) {
+	if (pmatch[i].rm_so == -1) {
+	    fprintf (stderr, "Internal error: matching regex against %s:"
+		     "Sub-match %d not found\n",
+		     string, i);
+	    exit (1);
+	}
+    }
+
+    return 0;
+}