[Driver] Add support for -fno-builtin-foo options.

Addresses PR4941 and rdar://6756912.
http://reviews.llvm.org/D15195

llvm-svn: 256937

2 files changed, 20 insertions, 2 deletions

diff --git a/clang/lib/Basic/Builtins.cpp b/clang/lib/Basic/Builtins.cpp
index 69b10c13ede..fb6a6451aa8 100644
--- a/clang/lib/Basic/Builtins.cpp
+++ b/clang/lib/Basic/Builtins.cpp
@@ -48,10 +48,20 @@ void Builtin::Context::InitializeTarget(const TargetInfo &Target,
     AuxTSRecords = AuxTarget->getTargetBuiltins();
 }
 
+bool Builtin::Context::isBuiltinFunc(const char *Name) {
+  StringRef FuncName(Name);
+  for (unsigned i = Builtin::NotBuiltin + 1; i != Builtin::FirstTSBuiltin; ++i)
+    if (FuncName.equals(BuiltinInfo[i].Name))
+      return strchr(BuiltinInfo[i].Attributes, 'f') != nullptr;
+
+  return false;
+}
+
 bool Builtin::Context::builtinIsSupported(const Builtin::Info &BuiltinInfo,
                                           const LangOptions &LangOpts) {
-  bool BuiltinsUnsupported = LangOpts.NoBuiltin &&
-                             strchr(BuiltinInfo.Attributes, 'f');
+  bool BuiltinsUnsupported =
+      (LangOpts.NoBuiltin || LangOpts.isNoBuiltinFunc(BuiltinInfo.Name)) &&
+      strchr(BuiltinInfo.Attributes, 'f');
   bool MathBuiltinsUnsupported =
     LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
     llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
diff --git a/clang/lib/Basic/LangOptions.cpp b/clang/lib/Basic/LangOptions.cpp
index 2c87845b7b0..1b08b068604 100644
--- a/clang/lib/Basic/LangOptions.cpp
+++ b/clang/lib/Basic/LangOptions.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 #include "clang/Basic/LangOptions.h"
+#include "llvm/ADT/StringRef.h"
 
 using namespace clang;
 
@@ -36,3 +37,10 @@ void LangOptions::resetNonModularOptions() {
   ImplementationOfModule.clear();
 }
 
+bool LangOptions::isNoBuiltinFunc(const char *Name) const {
+  StringRef FuncName(Name);
+  for (unsigned i = 0, e = NoBuiltinFuncs.size(); i != e; ++i)
+    if (FuncName.equals(NoBuiltinFuncs[i]))
+      return true;
+  return false;
+}