From 5e0efd53e797a2b5468b91b41b6122f3b942efb2 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@tinc-vpn.org>
Date: Tue, 8 Sep 2009 18:16:58 +0200
Subject: [PATCH] Add xasprintf() and xvasprintf().

These functions wrap asprintf() and vasprintf(), and check the return value. If
the function failed, tinc will exit with an error message, similar to xmalloc()
and friends.
---
 lib/dropin.c  | 25 +++++++++++++++++--------
 lib/dropin.h  |  1 +
 lib/xalloc.h  |  3 +++
 lib/xmalloc.c | 20 ++++++++++++++++++++
 4 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/lib/dropin.c b/lib/dropin.c
index a3c28b04..23d2b136 100644
--- a/lib/dropin.c
+++ b/lib/dropin.c
@@ -125,27 +125,36 @@ char *get_current_dir_name(void)
 #endif
 
 #ifndef HAVE_ASPRINTF
-int asprintf(char **buf, const char *fmt, ...)
+int asprintf(char **buf, const char *fmt, ...) {
+	int result;
+	va_list ap;
+	va_start(ap, fmt);
+	result = vasprintf(buf, fmt, ap);
+	va_end(ap);
+	return result;
+}
+
+int vasprintf(char **buf, const char *fmt, va_list ap) {
 {
 	int status;
-	va_list ap;
+	va_list aq;
 	int len;
 
 	len = 4096;
 	*buf = xmalloc(len);
 
-	va_start(ap, fmt);
-	status = vsnprintf(*buf, len, fmt, ap);
-	va_end(ap);
+	va_copy(aq, ap);
+	status = vsnprintf(*buf, len, fmt, aq);
+	va_end(aq);
 
 	if(status >= 0)
 		*buf = xrealloc(*buf, status + 1);
 
 	if(status > len - 1) {
 		len = status;
-		va_start(ap, fmt);
-		status = vsnprintf(*buf, len, fmt, ap);
-		va_end(ap);
+		va_copy(aq, ap);
+		status = vsnprintf(*buf, len, fmt, aq);
+		va_end(aq);
 	}
 
 	return status;
diff --git a/lib/dropin.h b/lib/dropin.h
index eabc4c4d..72109c84 100644
--- a/lib/dropin.h
+++ b/lib/dropin.h
@@ -36,6 +36,7 @@ extern char *get_current_dir_name(void);
 
 #ifndef HAVE_ASPRINTF
 extern int asprintf(char **, const char *, ...);
+extern int vasprintf(char **, const char *, va_list ap);
 #endif
 
 #ifndef HAVE_GETNAMEINFO
diff --git a/lib/xalloc.h b/lib/xalloc.h
index 7cb486a2..51f99bdf 100644
--- a/lib/xalloc.h
+++ b/lib/xalloc.h
@@ -24,3 +24,6 @@ void *xcalloc PARAMS ((size_t n, size_t s));
 void *xrealloc PARAMS ((void *p, size_t n)) __attribute__ ((__malloc__));
 
 char *xstrdup PARAMS ((const char *s)) __attribute__ ((__malloc__));
+
+extern int xasprintf(char **strp, const char *fmt, ...);
+extern int xvasprintf(char **strp, const char *fmt, va_list ap);
diff --git a/lib/xmalloc.c b/lib/xmalloc.c
index d02f41b9..51356e46 100644
--- a/lib/xmalloc.c
+++ b/lib/xmalloc.c
@@ -22,6 +22,8 @@
 #include <sys/types.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdarg.h>
+#include <errno.h>
 
 #if STDC_HEADERS
 # include <stdlib.h>
@@ -138,3 +140,21 @@ xcalloc (n, s)
 }
 
 #endif /* NOT_USED */
+
+int xasprintf(char **strp, const char *fmt, ...) {
+	int result;
+	va_list ap;
+	va_start(ap, fmt);
+	result = xvasprintf(strp, fmt, ap);
+	va_end(ap);
+	return result;
+}
+
+int xvasprintf(char **strp, const char *fmt, va_list ap) {
+	int result = vasprintf(strp, fmt, ap);
+	if(result < 0) {
+		fprintf(stderr, "vasprintf() failed: %s\n", strerror(errno));
+  		exit(xalloc_exit_failure);
+	}
+	return result;
+}
-- 
2.20.1