Fix handling of varargs function

Author: hoodmane

clang/lib/CodeGen/TargetBuiltins/WebAssembly.cpp

@@ -246,9 +246,10 @@ Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
     llvm::FunctionType *LLVMFuncTy =
         cast<llvm::FunctionType>(ConvertType(QualType(FuncTy, 0)));
 
+    bool VarArg = LLVMFuncTy->isVarArg();
     unsigned NParams = LLVMFuncTy->getNumParams();
     std::vector<Value *> Args;
-    Args.reserve(NParams + 3);
+    Args.reserve(NParams + 3 + VarArg);
     // The only real argument is the FuncRef
     Args.push_back(FuncRef);
 
@@ -263,6 +264,9 @@ Value *CodeGenFunction::EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
     for (unsigned i = 0; i < NParams; i++) {
       Args.push_back(PoisonValue::get(LLVMFuncTy->getParamType(i)));
     }
+    if (VarArg) {
+      Args.push_back(PoisonValue::get(Builder.getPtrTy()));
+    }
     Function *Callee = CGM.getIntrinsic(Intrinsic::wasm_ref_test_func);
     return Builder.CreateCall(Callee, Args);
   }

clang/test/CodeGen/builtins-wasm.c

@@ -755,6 +755,7 @@ void *tp (void) {
 typedef void (*Fvoid)(void);
 typedef float (*Ffloats)(float, double, int);
 typedef void (*Fpointers)(Fvoid, Ffloats, void*, int*, int***, char[5]);
+typedef void (*FVarArgs)(int, ...);
 typedef __externref_t (*FExternRef)(__externref_t, __externref_t);
 typedef __funcref Fpointers (*FFuncRef)(__funcref Fvoid, __funcref Ffloats);
 
@@ -775,6 +776,11 @@ void test_function_pointer_signature_pointers(Fpointers func) {
   use(__builtin_wasm_test_function_pointer_signature(func));
 }
 
+void test_function_pointer_signature_varargs(FVarArgs func) {
+  // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, token poison, i32 poison, ptr poison)
+  use(__builtin_wasm_test_function_pointer_signature(func));
+}
+
 void test_function_pointer_externref(FExternRef func) {
   // WEBASSEMBLY:  %0 = tail call i32 (ptr, ...) @llvm.wasm.ref.test.func(ptr %func, ptr addrspace(10) poison, token poison, ptr addrspace(10) poison, ptr addrspace(10) poison)
   use(__builtin_wasm_test_function_pointer_signature(func));