[ObjC][ARC] Check whether the return and parameter types of the old and

new functions are compatible before upgrading a function call to an
intrinsic call.

Sometimes users insert calls to ARC runtime functions that are not
compatible with the corresponding intrinsic functions (for example,
'i8* @objc_storeStrong' instead of 'void @objc_storeStrong'). Don't
upgrade those calls.

rdar://problem/56447127

llvm/lib/IR/AutoUpgrade.cpp

@@ -3877,15 +3877,36 @@ void llvm::UpgradeARCRuntime(Module &M) {
       FunctionType *NewFuncTy = NewFn->getFunctionType();
       SmallVector<Value *, 2> Args;
 
+      // Don't upgrade the intrinsic if it's not valid to bitcast the return
+      // value to the return type of the old function.
+      if (NewFuncTy->getReturnType() != CI->getType() &&
+          !CastInst::castIsValid(Instruction::BitCast, CI,
+                                 NewFuncTy->getReturnType()))
+        continue;
+
+      bool InvalidCast = false;
+
       for (unsigned I = 0, E = CI->getNumArgOperands(); I != E; ++I) {
         Value *Arg = CI->getArgOperand(I);
+
         // Bitcast argument to the parameter type of the new function if it's
         // not a variadic argument.
-        if (I < NewFuncTy->getNumParams())
+        if (I < NewFuncTy->getNumParams()) {
+          // Don't upgrade the intrinsic if it's not valid to bitcast the argument
+          // to the parameter type of the new function.
+          if (!CastInst::castIsValid(Instruction::BitCast, Arg,
+                                     NewFuncTy->getParamType(I))) {
+            InvalidCast = true;
+            break;
+          }
           Arg = Builder.CreateBitCast(Arg, NewFuncTy->getParamType(I));
+        }
         Args.push_back(Arg);
       }
 
+      if (InvalidCast)
+        continue;
+
       // Create a call instruction that calls the new function.
       CallInst *NewCall = Builder.CreateCall(NewFuncTy, NewFn, Args);
       NewCall->setTailCallKind(cast<CallInst>(CI)->getTailCallKind());

llvm/test/Bitcode/upgrade-arc-runtime-calls-bitcast.ll

@@ -0,0 +1,21 @@
+target triple = "arm64-apple-ios7.0"
+
+; RUN: llvm-dis < %S/upgrade-arc-runtime-calls-bitcast.bc | FileCheck %s
+
+; CHECK: tail call i8* @objc_retain(i32 1)
+; CHECK: tail call i8* @objc_storeStrong(
+
+define void @testRuntimeCalls(i8* %a, i8** %b) {
+  %v6 = tail call i8* @objc_retain(i32 1)
+  %1 = tail call i8* @objc_storeStrong(i8** %b, i8* %a)
+  ret void
+}
+
+declare i8* @objc_retain(i32)
+declare i8* @objc_storeStrong(i8**, i8*)
+
+attributes #0 = { nounwind }
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"clang.arc.retainAutoreleasedReturnValueMarker", !"mov\09fp, fp\09\09; marker for objc_retainAutoreleaseReturnValue"}