Index: compiler-rt/trunk/lib/asan/tests/asan_test.cc
===================================================================
--- compiler-rt/trunk/lib/asan/tests/asan_test.cc
+++ compiler-rt/trunk/lib/asan/tests/asan_test.cc
@@ -1284,3 +1284,33 @@
   ASSERT_EQ(0, res);
 }
 #endif
+
+#if SANITIZER_TEST_HAS_PRINTF_L
+static int vsnprintf_l_wrapper(char *s, size_t n,
+                               locale_t l, const char *format, ...) {
+  va_list va;
+  va_start(va, format);
+  int res = vsnprintf_l(s, n , l, format, va);
+  va_end(va);
+  return res;
+}
+
+TEST(AddressSanitizer, snprintf_l) {
+  char buff[5];
+  // Check that snprintf_l() works fine with Asan.
+  int res = snprintf_l(buff, 5,
+                       _LIBCPP_GET_C_LOCALE, "%s", "snprintf_l()");
+  EXPECT_EQ(12, res);
+  // Check that vsnprintf_l() works fine with Asan.
+  res = vsnprintf_l_wrapper(buff, 5,
+                            _LIBCPP_GET_C_LOCALE, "%s", "vsnprintf_l()");
+  EXPECT_EQ(13, res);
+
+  EXPECT_DEATH(snprintf_l(buff, 10,
+                          _LIBCPP_GET_C_LOCALE, "%s", "snprintf_l()"),
+                "AddressSanitizer: stack-buffer-overflow");
+  EXPECT_DEATH(vsnprintf_l_wrapper(buff, 10,
+                                  _LIBCPP_GET_C_LOCALE, "%s", "vsnprintf_l()"),
+                "AddressSanitizer: stack-buffer-overflow");
+}
+#endif
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
@@ -915,6 +915,16 @@
             va_list ap)
 VSNPRINTF_INTERCEPTOR_IMPL(vsnprintf, str, size, format, ap)
 
+#if SANITIZER_INTERCEPT_PRINTF_L
+INTERCEPTOR(int, vsnprintf_l, char *str, SIZE_T size, void *loc,
+            const char *format, va_list ap)
+VSNPRINTF_INTERCEPTOR_IMPL(vsnprintf_l, str, size, loc, format, ap)
+
+INTERCEPTOR(int, snprintf_l, char *str, SIZE_T size, void *loc,
+            const char *format, ...)
+FORMAT_INTERCEPTOR_IMPL(snprintf_l, vsnprintf_l, str, size, loc, format)
+#endif  // SANITIZER_INTERCEPT_PRINTF_L
+
 INTERCEPTOR(int, vsprintf, char *str, const char *format, va_list ap)
 VSPRINTF_INTERCEPTOR_IMPL(vsprintf, str, format, ap)
 
@@ -991,6 +1001,14 @@
 #define INIT_PRINTF
 #endif
 
+#if SANITIZER_INTERCEPT_PRINTF_L
+#define INIT_PRINTF_L                     \
+  COMMON_INTERCEPT_FUNCTION(snprintf_l);  \
+  COMMON_INTERCEPT_FUNCTION(vsnprintf_l);
+#else
+#define INIT_PRINTF_L
+#endif
+
 #if SANITIZER_INTERCEPT_ISOC99_PRINTF
 #define INIT_ISOC99_PRINTF                       \
   COMMON_INTERCEPT_FUNCTION(__isoc99_printf);    \
@@ -4768,6 +4786,7 @@
   INIT_SCANF;
   INIT_ISOC99_SCANF;
   INIT_PRINTF;
+  INIT_PRINTF_L;
   INIT_ISOC99_PRINTF;
   INIT_FREXP;
   INIT_FREXPF_FREXPL;
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
@@ -85,6 +85,7 @@
 
 #ifndef SANITIZER_INTERCEPT_PRINTF
 # define SANITIZER_INTERCEPT_PRINTF SI_NOT_WINDOWS
+# define SANITIZER_INTERCEPT_PRINTF_L SI_FREEBSD
 # define SANITIZER_INTERCEPT_ISOC99_PRINTF SI_LINUX_NOT_ANDROID
 #endif
 
Index: compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_test_utils.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_test_utils.h
+++ compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_test_utils.h
@@ -118,4 +118,10 @@
 # define SANITIZER_TEST_HAS_STRNLEN 0
 #endif
 
+#if defined(__FreeBSD__)
+# define SANITIZER_TEST_HAS_PRINTF_L 1
+#else
+# define SANITIZER_TEST_HAS_PRINTF_L 0
+#endif
+
 #endif  // SANITIZER_TEST_UTILS_H