[PATCH] D61803: [CodeGen][ObjC] Emit invoke instead of call to call `objc_release` when necessary.

[Akira Hatanaka via Phabricator via cfe-commits]

ahatanak created this revision.
ahatanak added reviewers: pete, rjmccall.
ahatanak added a project: clang.
Herald added subscribers: dexonsmith, jkorous.

Prior to r349952, clang used to call `objc_msgSend` when sending a release messages, emitting an invoke instruction instead of a call instruction when it was necessary to catch an exception. That changed in r349952 because runtime function `objc_release` is called as a nounwind function, which broke programs that were overriding the `dealloc` method and throwing an exception from it. This patch restores the behavior prior to r349952.

rdar://problem/50253394


Repository:
  rC Clang

https://reviews.llvm.org/D61803

Files:
  lib/CodeGen/CGObjC.cpp
  test/CodeGenObjC/convert-messages-to-runtime-calls.m


Index: test/CodeGenObjC/convert-messages-to-runtime-calls.m
===================================================================
--- test/CodeGenObjC/convert-messages-to-runtime-calls.m
+++ test/CodeGenObjC/convert-messages-to-runtime-calls.m
@@ -175,3 +175,14 @@
 
 @end
 
+ at class Ety;
+
+// CHECK-LABEL: define {{.*}}void @testException
+void testException(NSObject *a) {
+  // MSGS: {{invoke.*@objc_msgSend}}
+  // CALLS: invoke{{.*}}void @objc_release(i8* %
+  @try {
+    [a release];
+  } @catch (Ety *e) {
+  }
+}
Index: lib/CodeGen/CGObjC.cpp
===================================================================
--- lib/CodeGen/CGObjC.cpp
+++ lib/CodeGen/CGObjC.cpp
@@ -2631,7 +2631,19 @@
   value = Builder.CreateBitCast(value, Int8PtrTy);
 
   // Call objc_release.
-  llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value);
+  ASTContext &Ctx = getContext();
+  const ImplicitParamDecl *paramDecl =
+      ImplicitParamDecl::Create(Ctx, nullptr, SourceLocation(), nullptr,
+                                Ctx.VoidPtrTy, ImplicitParamDecl::Other);
+  FunctionArgList funcArgs;
+  funcArgs.push_back(paramDecl);
+  const CGFunctionInfo &fnInfo =
+      CGM.getTypes().arrangeBuiltinFunctionDeclaration(Ctx.VoidTy, funcArgs);
+  CallArgList args;
+  args.add(RValue::get(value), Ctx.VoidPtrTy);
+  llvm::CallBase *call;
+  EmitCall(fnInfo, CGCallee::forDirect(cast<llvm::Constant>(fn.getCallee())),
+           ReturnValueSlot(), args, &call);
 
   if (precise == ARCImpreciseLifetime) {
     call->setMetadata("clang.imprecise_release",


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