Add verifier check that musttail and preallocated are not used together

Summary:
Currently they are not supported together. Supporting them will require
a LangRef change. See discussion in https://reviews.llvm.org/D77689.

Reviewers: rnk, efriedma

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80132

llvm/lib/IR/Verifier.cpp

@@ -3150,6 +3150,9 @@ static AttrBuilder getParameterABIAttributes(int I, AttributeList Attrs) {
 
 void Verifier::verifyMustTailCall(CallInst &CI) {
   Assert(!CI.isInlineAsm(), "cannot use musttail call with inline asm", &CI);
+  // FIXME: support musttail + preallocated
+  Assert(!CI.countOperandBundlesOfType(LLVMContext::OB_preallocated),
+         "musttail and preallocated not yet supported", &CI);
 
   // - The caller and callee prototypes must match.  Pointer types of
   //   parameters or return types may differ in pointee type, but not

llvm/test/Verifier/preallocated-invalid.ll

@@ -116,3 +116,10 @@ define void @preallocated_arg_token() {
     %x = call i8* @llvm.call.preallocated.arg(token %t, i32 1) preallocated(i32)
     ret void
 }
+
+; CHECK: musttail and preallocated not yet supported
+define void @musttail() {
+    %cs = call token @llvm.call.preallocated.setup(i32 0)
+    musttail call void @foo0() ["preallocated"(token %cs)]
+    ret void
+}