[IR] Remove some uses of StructType::setBody. NFC. (#113685)

It is simple to create the struct body up front, now that we have
transitioned to opaque pointers.

Author: jayfoad

llvm/lib/CodeGen/ShadowStackGCLowering.cpp

@@ -242,13 +242,12 @@ bool ShadowStackGCLoweringImpl::doInitialization(Module &M) {
   //   void *Roots[];          // Stack roots (in-place array, so we pretend).
   // };
 
-  StackEntryTy = StructType::create(M.getContext(), "gc_stackentry");
+  PointerType *StackEntryPtrTy = PointerType::getUnqual(M.getContext());
 
   EltTys.clear();
-  EltTys.push_back(PointerType::getUnqual(StackEntryTy));
+  EltTys.push_back(StackEntryPtrTy);
   EltTys.push_back(FrameMapPtrTy);
-  StackEntryTy->setBody(EltTys);
-  PointerType *StackEntryPtrTy = PointerType::getUnqual(StackEntryTy);
+  StackEntryTy = StructType::create(EltTys, "gc_stackentry");
 
   // Get the root chain if it already exists.
   Head = M.getGlobalVariable("llvm_gc_root_chain");

llvm/lib/Target/X86/X86WinEHState.cpp

@@ -210,13 +210,11 @@ Type *WinEHStatePass::getEHLinkRegistrationType() {
   if (EHLinkRegistrationTy)
     return EHLinkRegistrationTy;
   LLVMContext &Context = TheModule->getContext();
-  EHLinkRegistrationTy = StructType::create(Context, "EHRegistrationNode");
   Type *FieldTys[] = {
-      PointerType::getUnqual(
-          EHLinkRegistrationTy->getContext()), // EHRegistrationNode *Next
-      PointerType::getUnqual(Context) // EXCEPTION_DISPOSITION (*Handler)(...)
+      PointerType::getUnqual(Context), // EHRegistrationNode *Next
+      PointerType::getUnqual(Context)  // EXCEPTION_DISPOSITION (*Handler)(...)
   };
-  EHLinkRegistrationTy->setBody(FieldTys, false);
+  EHLinkRegistrationTy = StructType::create(FieldTys, "EHRegistrationNode");
   return EHLinkRegistrationTy;
 }
 

llvm/lib/Transforms/Coroutines/CoroEarly.cpp

@@ -123,11 +123,11 @@ void Lowerer::lowerCoroNoop(IntrinsicInst *II) {
     Module &M = *II->getModule();
 
     // Create a noop.frame struct type.
-    StructType *FrameTy = StructType::create(C, "NoopCoro.Frame");
     auto *FnTy = FunctionType::get(Type::getVoidTy(C), Builder.getPtrTy(0),
                                    /*isVarArg=*/false);
     auto *FnPtrTy = Builder.getPtrTy(0);
-    FrameTy->setBody({FnPtrTy, FnPtrTy});
+    StructType *FrameTy =
+        StructType::create({FnPtrTy, FnPtrTy}, "NoopCoro.Frame");
 
     // Create a Noop function that does nothing.
     Function *NoopFn =

llvm/lib/Transforms/Coroutines/CoroFrame.cpp

@@ -290,8 +290,8 @@ class FrameTypeBuilder {
     return Fields.size() - 1;
   }
 
-  /// Finish the layout and set the body on the given type.
-  void finish(StructType *Ty);
+  /// Finish the layout and create the struct type with the given name.
+  StructType *finish(StringRef Name);
 
   uint64_t getStructSize() const {
     assert(IsFinished && "not yet finished!");
@@ -464,7 +464,7 @@ void FrameTypeBuilder::addFieldForAllocas(const Function &F,
   });
 }
 
-void FrameTypeBuilder::finish(StructType *Ty) {
+StructType *FrameTypeBuilder::finish(StringRef Name) {
   assert(!IsFinished && "already finished!");
 
   // Prepare the optimal-layout field array.
@@ -526,7 +526,7 @@ void FrameTypeBuilder::finish(StructType *Ty) {
     LastOffset = Offset + F.Size;
   }
 
-  Ty->setBody(FieldTypes, Packed);
+  StructType *Ty = StructType::create(Context, FieldTypes, Name, Packed);
 
 #ifndef NDEBUG
   // Check that the IR layout matches the offsets we expect.
@@ -538,6 +538,8 @@ void FrameTypeBuilder::finish(StructType *Ty) {
 #endif
 
   IsFinished = true;
+
+  return Ty;
 }
 
 static void cacheDIVar(FrameDataInfo &FrameData,
@@ -866,11 +868,6 @@ static StructType *buildFrameType(Function &F, coro::Shape &Shape,
                                   bool OptimizeFrame) {
   LLVMContext &C = F.getContext();
   const DataLayout &DL = F.getDataLayout();
-  StructType *FrameTy = [&] {
-    SmallString<32> Name(F.getName());
-    Name.append(".Frame");
-    return StructType::create(C, Name);
-  }();
 
   // We will use this value to cap the alignment of spilled values.
   std::optional<Align> MaxFrameAlignment;
@@ -931,7 +928,12 @@ static StructType *buildFrameType(Function &F, coro::Shape &Shape,
     FrameData.setFieldIndex(S.first, Id);
   }
 
-  B.finish(FrameTy);
+  StructType *FrameTy = [&] {
+    SmallString<32> Name(F.getName());
+    Name.append(".Frame");
+    return B.finish(Name);
+  }();
+
   FrameData.updateLayoutIndex(B);
   Shape.FrameAlign = B.getStructAlign();
   Shape.FrameSize = B.getStructSize();