Add GNU-compatible strerror_r.
We already had the POSIX strerror_r, but some third-party code defines
_GNU_SOURCE and expects to get the GNU strerror_r instead.
This exposed a bug in the libc internal logging functions where unlike
their standard brethren they wouldn't return the number of bytes they'd
have liked to have written.
Bug: 16243479
Change-Id: I1745752ccbdc569646d34f5071f6df2be066d5f4
diff --git a/libc/bionic/strerror_r.cpp b/libc/bionic/strerror_r.cpp
index 1e57cc0..d419fb1 100644
--- a/libc/bionic/strerror_r.cpp
+++ b/libc/bionic/strerror_r.cpp
@@ -1,11 +1,16 @@
/* $OpenBSD: strerror_r.c,v 1.6 2005/08/08 08:05:37 espie Exp $ */
/* Public Domain <marc@snafu.org> */
+// G++ automatically defines _GNU_SOURCE, which then means that <string.h>
+// gives us the GNU variant.
+#undef _GNU_SOURCE
+
+#include <string.h>
+
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
-#include <string.h>
#include "private/ErrnoRestorer.h"
#include "private/libc_logging.h"
@@ -62,6 +67,12 @@
return 0;
}
+extern "C" char* __gnu_strerror_r(int error_number, char* buf, size_t buf_len) {
+ ErrnoRestorer errno_restorer; // The glibc strerror_r doesn't set errno if it truncates...
+ strerror_r(error_number, buf, buf_len);
+ return buf; // ...and just returns whatever fit.
+}
+
extern "C" __LIBC_HIDDEN__ const char* __strsignal(int signal_number, char* buf, size_t buf_len) {
const char* signal_name = __strsignal_lookup(signal_number);
if (signal_name != NULL) {