Declare 'strerror' so that we can use it with errno.
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@185105 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/SDKs/darwin/usr/include/string.h b/SDKs/darwin/usr/include/string.h
index c7da1f5..c6ab5d8 100644
--- a/SDKs/darwin/usr/include/string.h
+++ b/SDKs/darwin/usr/include/string.h
@@ -28,4 +28,25 @@
size_t strlen(const char *);
char *strncpy(char *, const char *, size_t);
+/* Determine the appropriate strerror() function. */
+#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
+# if defined(__i386)
+# define __STRERROR_NAME "_strerror$UNIX2003"
+# elif defined(__x86_64__) || defined(__arm)
+# define __STRERROR_NAME "_strerror"
+# else
+# error "unrecognized architecture for targetting OS X"
+# endif
+#elif defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__)
+# if defined(__i386) || defined (__x86_64) || defined(__arm)
+# define __STRERROR_NAME "_strerror"
+# else
+# error "unrecognized architecture for targetting iOS"
+# endif
+#else
+# error "unrecognized architecture for targetting Darwin"
+#endif
+
+char *strerror(int) __asm(__STRERROR_NAME);
+
#endif /* __STRING_H__ */
