Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -6734,6 +6734,23 @@
 #define INIT_WCSCAT
 #endif
 
+#if SANITIZER_INTERCEPT_WCSDUP
+INTERCEPTOR(wchar_t *, wcsdup, wchar_t *s) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, wcsdup, s);
+  SIZE_T len = REAL(wcslen)(s);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s, sizeof(wchar_t) * (len + 1));
+  wchar_t *result = REAL(wcsdup)(s);
+  if (result)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, result, sizeof(wchar_t) * (len + 1));
+  return result;
+}
+
+#define INIT_WCSDUP COMMON_INTERCEPT_FUNCTION(wcsdup);
+#else
+#define INIT_WCSDUP
+#endif
+
 #if SANITIZER_INTERCEPT_STRXFRM
 static SIZE_T RealStrLen(const char *str) { return REAL(strlen)(str); }
 
@@ -9765,6 +9782,7 @@
   INIT_GETLOADAVG;
   INIT_WCSLEN;
   INIT_WCSCAT;
+  INIT_WCSDUP;
   INIT_WCSXFRM;
   INIT___WCSXFRM_L;
   INIT_ACCT;
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -492,6 +492,7 @@
 #define SANITIZER_INTERCEPT_MALLOC_USABLE_SIZE (!SI_MAC && !SI_OPENBSD)
 #define SANITIZER_INTERCEPT_MCHECK_MPROBE SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_WCSCAT SI_POSIX
+#define SANITIZER_INTERCEPT_WCSDUP SI_POSIX
 #define SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION (!SI_WINDOWS && SI_NOT_FUCHSIA)
 #define SANITIZER_INTERCEPT_BSD_SIGNAL SI_ANDROID
 
Index: compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/wcsdup.c
===================================================================
--- compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/wcsdup.c
+++ compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/wcsdup.c
@@ -0,0 +1,15 @@
+// RUN: %clang %s -o %t && %run %t 2>&1
+
+#include <assert.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+int main(int argc, char **argv) {
+  wchar_t *buff = wcsdup(L"foo");
+  assert(buff[0] == L'f');
+  assert(buff[1] == L'o');
+  assert(buff[2] == L'o');
+  assert(buff[3] == L'\0');
+  free(buff);
+  return 0;
+}