3 files changed, 1 insertions, 15 deletions

diff --git a/clang/lib/Driver/Job.cpp b/clang/lib/Driver/Job.cpp
index b494bc75282..765c05752d8 100644
--- a/clang/lib/Driver/Job.cpp
+++ b/clang/lib/Driver/Job.cpp
@@ -64,7 +64,7 @@ static bool skipArgs(const char *Flag, bool HaveCrashVFS, int &SkipNum,
     .Cases("-internal-externc-isystem", "-iprefix", true)
     .Cases("-iwithprefixbefore", "-isystem", "-iquote", true)
     .Cases("-isysroot", "-I", "-F", "-resource-dir", true)
-    .Cases("-iframework", "-include-pch", "-fsystem-include-if-exists", true)
+    .Cases("-iframework", "-include-pch", true)
     .Default(false);
   if (IsInclude)
     return HaveCrashVFS ? false : true;
diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 5c3697391d5..1301cdf114a 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -710,8 +710,6 @@ void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/include");
 
   addExternCSystemInclude(DriverArgs, CC1Args, SysRoot + "/usr/include");
-
-  AddGnuIncludeArgs(DriverArgs, CC1Args);
 }
 
 static std::string DetectLibcxxIncludePath(StringRef base) {
@@ -750,16 +748,6 @@ std::string Linux::findLibCxxIncludePath() const {
   return "";
 }
 
-void Linux::AddGnuIncludeArgs(const llvm::opt::ArgList &DriverArgs,
-                              llvm::opt::ArgStringList &CC1Args) const {
-  if (!DriverArgs.hasArg(options::OPT_ffreestanding)) {
-    // For gcc compatibility, clang will preinclude <stdc-predef.h>
-    // -ffreestanding suppresses this behavior.
-    CC1Args.push_back("-fsystem-include-if-exists");
-    CC1Args.push_back("stdc-predef.h");
-  }
-}
-
 void Linux::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
                                      llvm::opt::ArgStringList &CC1Args) const {
   // We need a detected GCC installation on Linux to provide libstdc++'s
diff --git a/clang/lib/Driver/ToolChains/Linux.h b/clang/lib/Driver/ToolChains/Linux.h
index 8b7e2e2ad53..9778c1832cc 100644
--- a/clang/lib/Driver/ToolChains/Linux.h
+++ b/clang/lib/Driver/ToolChains/Linux.h
@@ -31,8 +31,6 @@ public:
   void addLibStdCxxIncludePaths(
       const llvm::opt::ArgList &DriverArgs,
       llvm::opt::ArgStringList &CC1Args) const override;
-  void AddGnuIncludeArgs(const llvm::opt::ArgList &DriverArgs,
-                          llvm::opt::ArgStringList &CC1Args) const;
   void AddCudaIncludeArgs(const llvm::opt::ArgList &DriverArgs,
                           llvm::opt::ArgStringList &CC1Args) const override;
   void AddIAMCUIncludeArgs(const llvm::opt::ArgList &DriverArgs,