[Clang][Codegen] Do not annotate thunk's this/return types with align/deref/nonnull attrs

As it was discovered in post-commit feedback
for 0aa0458f1429372038ca6a4edc7e94c96cd9a753,
we handle thunks incorrectly, and end up annotating
their this/return with attributes that are valid
for their callees, not for thunks themselves.

While it would be good to fix this properly,
and keep annotating them on thunks,
i've tried doing that in https://reviews.llvm.org/D100388
with little success, and the patch is stuck for a month now.

So for now, as a stopgap measure, subj.

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index e3c843c8e9d3..b408ea30e423 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1466,10 +1466,11 @@ llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
 
 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
                                               const CGFunctionInfo &Info,
-                                              llvm::Function *F) {
+                                              llvm::Function *F, bool IsThunk) {
   unsigned CallingConv;
   llvm::AttributeList PAL;
-  ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false);
+  ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
+                         /*AttrOnCallSite=*/false, IsThunk);
   F->setAttributes(PAL);
   F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
 }
@@ -2008,7 +2009,7 @@ void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
                                                   llvm::Function *F,
                                                   const CGFunctionInfo &FI) {
   const Decl *D = GD.getDecl();
-  SetLLVMFunctionAttributes(GD, FI, F);
+  SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
   SetLLVMFunctionAttributesForDefinition(D, F);
 
   F->setLinkage(llvm::Function::InternalLinkage);
@@ -2062,7 +2063,8 @@ void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
   const auto *FD = cast<FunctionDecl>(GD.getDecl());
 
   if (!IsIncompleteFunction)
-    SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F);
+    SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F,
+                              IsThunk);
 
   // Add the Returned attribute for "this", except for iOS 5 and earlier
   // where substantial code, including the libstdc++ dylib, was compiled with