2 files changed, 30 insertions, 4 deletions
diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index e7540a180a..e8d06f994f 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -659,6 +659,17 @@ def isystem : JoinedOrSeparate<"-isystem">, MetaVarName<"<directory>">,
 def iwithsysroot : JoinedOrSeparate<"-iwithsysroot">,MetaVarName<"<directory>">,
   HelpText<"Add directory to SYSTEM include search path, "
            "absolute paths are relative to -isysroot">;
+def internal_isystem : JoinedOrSeparate<"-internal-isystem">,
+  MetaVarName<"<directory>">,
+  HelpText<"Add directory to the internal system include search path; these "
+           "are assumed to not be user-provided and are used to model system "
+           "and standard headers' paths.">;
+def internal_externc_isystem : JoinedOrSeparate<"-internal-externc-isystem">,
+  MetaVarName<"<directory>">,
+  HelpText<"Add directory to the internal system include search path with "
+           "implicit extern \"C\" semantics; these are assumed to not be "
+           "user-provided and are used to model system and standard headers' "
+           "paths.">;
 def iprefix : JoinedOrSeparate<"-iprefix">, MetaVarName<"<prefix>">,
   HelpText<"Set the -iwithprefix/-iwithprefixbefore prefix">;
 def iwithprefix : JoinedOrSeparate<"-iwithprefix">, MetaVarName<"<dir>">,
diff --git a/include/clang/Frontend/HeaderSearchOptions.h b/include/clang/Frontend/HeaderSearchOptions.h
index 92790e99d8..687f439fe1 100644
--- a/include/clang/Frontend/HeaderSearchOptions.h
+++ b/include/clang/Frontend/HeaderSearchOptions.h
@@ -49,10 +49,24 @@ public:
     /// path.
     unsigned IgnoreSysRoot : 1;
 
+    /// \brief True if this entry is an internal search path.
+    ///
+    /// This typically indicates that users didn't directly provide it, but
+    /// instead it was provided by a compatibility layer for a particular
+    /// system. This isn't redundant with IsUserSupplied (even though perhaps
+    /// it should be) because that is false for user provided '-iwithprefix'
+    /// header search entries.
+    unsigned IsInternal : 1;
+
+    /// \brief True if this entry's headers should be wrapped in extern "C".
+    unsigned ImplicitExternC : 1;
+
     Entry(StringRef path, frontend::IncludeDirGroup group,
-          bool isUserSupplied, bool isFramework, bool ignoreSysRoot)
+          bool isUserSupplied, bool isFramework, bool ignoreSysRoot,
+          bool isInternal, bool implicitExternC)
       : Path(path), Group(group), IsUserSupplied(isUserSupplied),
-        IsFramework(isFramework), IgnoreSysRoot(ignoreSysRoot) {}
+        IsFramework(isFramework), IgnoreSysRoot(ignoreSysRoot),
+        IsInternal(isInternal), ImplicitExternC(implicitExternC) {}
   };
 
   /// If non-empty, the directory to use as a "virtual system root" for include
@@ -98,9 +112,10 @@ public:
 
   /// AddPath - Add the \arg Path path to the specified \arg Group list.
   void AddPath(StringRef Path, frontend::IncludeDirGroup Group,
-               bool IsUserSupplied, bool IsFramework, bool IgnoreSysRoot) {
+               bool IsUserSupplied, bool IsFramework, bool IgnoreSysRoot,
+               bool IsInternal = false, bool ImplicitExternC = false) {
     UserEntries.push_back(Entry(Path, Group, IsUserSupplied, IsFramework,
-                                IgnoreSysRoot));
+                                IgnoreSysRoot, IsInternal, ImplicitExternC));
   }
 };