1 files changed, 13 insertions, 6 deletions
diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp
index d65d13489dc4..5d877ee9c0d7 100644
--- a/lib/Frontend/InitHeaderSearch.cpp
+++ b/lib/Frontend/InitHeaderSearch.cpp
@@ -137,6 +137,13 @@ bool InitHeaderSearch::AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
   SmallString<256> MappedPathStorage;
   StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
 
+  // If use system headers while cross-compiling, emit the warning.
+  if (HasSysroot && (MappedPathStr.startswith("/usr/include") ||
+                     MappedPathStr.startswith("/usr/local/include"))) {
+    Headers.getDiags().Report(diag::warn_poison_system_directories)
+        << MappedPathStr;
+  }
+
   // Compute the DirectoryLookup type.
   SrcMgr::CharacteristicKind Type;
   if (Group == Quoted || Group == Angled || Group == IndexHeaderMap) {
@@ -148,17 +155,17 @@ bool InitHeaderSearch::AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
   }
 
   // If the directory exists, add it.
-  if (const DirectoryEntry *DE = FM.getDirectory(MappedPathStr)) {
+  if (auto DE = FM.getOptionalDirectoryRef(MappedPathStr)) {
     IncludePath.push_back(
-      std::make_pair(Group, DirectoryLookup(DE, Type, isFramework)));
+      std::make_pair(Group, DirectoryLookup(*DE, Type, isFramework)));
     return true;
   }
 
   // Check to see if this is an apple-style headermap (which are not allowed to
   // be frameworks).
   if (!isFramework) {
-    if (const FileEntry *FE = FM.getFile(MappedPathStr)) {
-      if (const HeaderMap *HM = Headers.CreateHeaderMap(FE)) {
+    if (auto FE = FM.getFile(MappedPathStr)) {
+      if (const HeaderMap *HM = Headers.CreateHeaderMap(*FE)) {
         // It is a headermap, add it to the search path.
         IncludePath.push_back(
           std::make_pair(Group,
@@ -636,8 +643,8 @@ void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
     // Set up the builtin include directory in the module map.
     SmallString<128> P = StringRef(HSOpts.ResourceDir);
     llvm::sys::path::append(P, "include");
-    if (const DirectoryEntry *Dir = HS.getFileMgr().getDirectory(P))
-      HS.getModuleMap().setBuiltinIncludeDir(Dir);
+    if (auto Dir = HS.getFileMgr().getDirectory(P))
+      HS.getModuleMap().setBuiltinIncludeDir(*Dir);
   }
 
   Init.Realize(Lang);