[CodeGen][ObjC] Emit invoke instead of call to call `objc_release` when

necessary.

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

Differential Revision: https://reviews.llvm.org/D61803

llvm-svn: 360474

diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index d5906cf..5b67565 100644 (file)
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -2631,7 +2631,7 @@ void CodeGenFunction::EmitObjCRelease(llvm::Value *value,
   value = Builder.CreateBitCast(value, Int8PtrTy);
 
   // Call objc_release.
-  llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value);
+  llvm::CallBase *call = EmitCallOrInvoke(fn, value);
 
   if (precise == ARCImpreciseLifetime) {
     call->setMetadata("clang.imprecise_release",

diff --git a/clang/test/CodeGenObjC/convert-messages-to-runtime-calls.m b/clang/test/CodeGenObjC/convert-messages-to-runtime-calls.m
index 39a2647..d1a9624 100644 (file)
--- a/clang/test/CodeGenObjC/convert-messages-to-runtime-calls.m
+++ b/clang/test/CodeGenObjC/convert-messages-to-runtime-calls.m
@@ -175,3 +175,14 @@ float test_cannot_message_return_float(C *c) {
 
 @end
 
+@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) {
+  }
+}