2 files changed, 49 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 1923c587291..71705146a17 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -30,6 +30,7 @@
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/MDBuilder.h"
+#include "llvm/Support/ConvertUTF.h"
 #include <sstream>
 
 using namespace clang;
@@ -1953,6 +1954,28 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
         Builder.CreateZExt(EmitSignBit(*this, EmitScalarExpr(E->getArg(0))),
                            ConvertType(E->getType())));
   }
+  case Builtin::BI__annotation: {
+    // Re-encode each wide string to UTF8 and make an MDString.
+    SmallVector<Metadata *, 1> Strings;
+    for (const Expr *Arg : E->arguments()) {
+      const auto *Str = cast<StringLiteral>(Arg->IgnoreParenCasts());
+      assert(Str->getCharByteWidth() == 2);
+      StringRef WideBytes = Str->getBytes();
+      std::string StrUtf8;
+      if (!convertUTF16ToUTF8String(
+              makeArrayRef(WideBytes.data(), WideBytes.size()), StrUtf8)) {
+        CGM.ErrorUnsupported(E, "non-UTF16 __annotation argument");
+        continue;
+      }
+      Strings.push_back(llvm::MDString::get(getLLVMContext(), StrUtf8));
+    }
+
+    // Build and MDTuple of MDStrings and emit the intrinsic call.
+    llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::label_annotation, {});
+    MDTuple *StrTuple = MDTuple::get(getLLVMContext(), Strings);
+    Builder.CreateCall(F, MetadataAsValue::get(getLLVMContext(), StrTuple));
+    return RValue::getIgnored();
+  }
   case Builtin::BI__builtin_annotation: {
     llvm::Value *AnnVal = EmitScalarExpr(E->getArg(0));
     llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::annotation,
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 31700e78939..7b0f72fd998 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -99,6 +99,28 @@ static bool SemaBuiltinAnnotation(Sema &S, CallExpr *TheCall) {
   return false;
 }
 
+static bool SemaBuiltinMSVCAnnotation(Sema &S, CallExpr *TheCall) {
+  // We need at least one argument.
+  if (TheCall->getNumArgs() < 1) {
+    S.Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args_at_least)
+        << 0 << 1 << TheCall->getNumArgs()
+        << TheCall->getCallee()->getSourceRange();
+    return true;
+  }
+
+  // All arguments should be wide string literals.
+  for (Expr *Arg : TheCall->arguments()) {
+    auto *Literal = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
+    if (!Literal || !Literal->isWide()) {
+      S.Diag(Arg->getLocStart(), diag::err_msvc_annotation_wide_str)
+          << Arg->getSourceRange();
+      return true;
+    }
+  }
+
+  return false;
+}
+
 /// Check that the argument to __builtin_addressof is a glvalue, and set the
 /// result type to the corresponding pointer type.
 static bool SemaBuiltinAddressof(Sema &S, CallExpr *TheCall) {
@@ -1000,6 +1022,10 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
   case Builtin::BI##ID: \
     return SemaAtomicOpsOverloaded(TheCallResult, AtomicExpr::AO##ID);
 #include "clang/Basic/Builtins.def"
+  case Builtin::BI__annotation:
+    if (SemaBuiltinMSVCAnnotation(*this, TheCall))
+      return ExprError();
+    break;
   case Builtin::BI__builtin_annotation:
     if (SemaBuiltinAnnotation(*this, TheCall))
       return ExprError();