1 files changed, 29 insertions, 9 deletions

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 5dea876451f..70cb4713e69 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1391,8 +1391,19 @@ llvm::Type *CodeGenTypes::GetFunctionTypeForVTable(GlobalDecl GD) {
   return GetFunctionType(*Info);
 }
 
+static void AddAttributesFromFunctionProtoType(ASTContext &Ctx,
+                                               llvm::AttrBuilder &FuncAttrs,
+                                               const FunctionProtoType *FPT) {
+  if (!FPT)
+    return;
+
+  if (!isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
+      FPT->isNothrow(Ctx))
+    FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
+}
+
 void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
-                                           const Decl *TargetDecl,
+                                           CGCalleeInfo CalleeInfo,
                                            AttributeListType &PAL,
                                            unsigned &CallingConv,
                                            bool AttrOnCallSite) {
@@ -1405,6 +1416,13 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
   if (FI.isNoReturn())
     FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
 
+  // If we have information about the function prototype, we can learn
+  // attributes form there.
+  AddAttributesFromFunctionProtoType(getContext(), FuncAttrs,
+                                     CalleeInfo.getCalleeFunctionProtoType());
+
+  const Decl *TargetDecl = CalleeInfo.getCalleeDecl();
+
   // FIXME: handle sseregparm someday...
   if (TargetDecl) {
     if (TargetDecl->hasAttr<ReturnsTwiceAttr>())
@@ -1417,10 +1435,8 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
       FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate);
 
     if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) {
-      const FunctionProtoType *FPT = Fn->getType()->getAs<FunctionProtoType>();
-      if (FPT && !isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
-          FPT->isNothrow(getContext()))
-        FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
+      AddAttributesFromFunctionProtoType(
+          getContext(), FuncAttrs, Fn->getType()->getAs<FunctionProtoType>());
       // Don't use [[noreturn]] or _Noreturn for a call to a virtual function.
       // These attributes are not inherited by overloads.
       const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn);
@@ -3077,7 +3093,7 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
                                  llvm::Value *Callee,
                                  ReturnValueSlot ReturnValue,
                                  const CallArgList &CallArgs,
-                                 const Decl *TargetDecl,
+                                 CGCalleeInfo CalleeInfo,
                                  llvm::Instruction **callOrInvoke) {
   // FIXME: We no longer need the types from CallArgs; lift up and simplify.
 
@@ -3406,8 +3422,8 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
 
   unsigned CallingConv;
   CodeGen::AttributeListType AttributeList;
-  CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList,
-                             CallingConv, true);
+  CGM.ConstructAttributeList(CallInfo, CalleeInfo, AttributeList, CallingConv,
+                             true);
   llvm::AttributeSet Attrs = llvm::AttributeSet::get(getLLVMContext(),
                                                      AttributeList);
 
@@ -3487,9 +3503,11 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   // lexical order, so deactivate it and run it manually here.
   CallArgs.freeArgumentMemory(*this);
 
-  if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(CI))
+  if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(CI)) {
+    const Decl *TargetDecl = CalleeInfo.getCalleeDecl();
     if (TargetDecl && TargetDecl->hasAttr<NotTailCalledAttr>())
       Call->setTailCallKind(llvm::CallInst::TCK_NoTail);
+  }
 
   RValue Ret = [&] {
     switch (RetAI.getKind()) {
@@ -3562,6 +3580,8 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
     llvm_unreachable("Unhandled ABIArgInfo::Kind");
   } ();
 
+  const Decl *TargetDecl = CalleeInfo.getCalleeDecl();
+
   if (Ret.isScalar() && TargetDecl) {
     if (const auto *AA = TargetDecl->getAttr<AssumeAlignedAttr>()) {
       llvm::Value *OffsetValue = nullptr;