From e5ebd2e120ee1fd15d69079df0773babda583b6d Mon Sep 17 00:00:00 2001
From: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
Date: Tue, 20 Dec 2016 15:53:39 -0800
Subject: [PATCH 1007/1008] Fix build issues pre-Lion due to missing a strnlen
 definition

https://trac.macports.org/ticket/51520
https://llvm.org/bugs/show_bug.cgi?id=27714

Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
---
 lib/Lex/HeaderMap.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git llvm_release_50/tools/clang/lib/Lex/HeaderMap.cpp macports_release_50/tools/clang/lib/Lex/HeaderMap.cpp
index 24a14b6cdb..c38986d46c 100644
--- llvm_release_50/tools/clang/lib/Lex/HeaderMap.cpp
+++ macports_release_50/tools/clang/lib/Lex/HeaderMap.cpp
@@ -26,6 +26,20 @@
 #include <memory>
 using namespace clang;
 
+#ifdef __APPLE__
+#include <Availability.h>
+#if __MAC_OS_X_VERSION_MIN_REQUIRED < 1070
+static size_t strnlen(const char *s, size_t maxlen) {
+  size_t l = 0;
+  while (l < maxlen && *s) {
+    l++;
+    s++;
+  }
+  return l;
+}
+#endif
+#endif
+
 /// HashHMapKey - This is the 'well known' hash function required by the file
 /// format, used to look up keys in the hash table.  The hash table uses simple
 /// linear probing based on this function.
-- 
2.13.3