[CodeGen] Avoid destructing a callee-destructued struct type in a

function if a function delegates to another function.

Fix a bug introduced in r328731, which caused a struct with ObjC __weak
fields that was passed to a function to be destructed twice, once in the
callee function and once in another function the callee function
delegates to. To prevent this, keep track of the callee-destructed
structs passed to a function and disable their cleanups at the point of
the call to the delegated function.

This reapplies r331016, which was reverted in r331019 because it caused
an assertion to fail in EmitDelegateCallArg on a windows bot. I made
changes to EmitDelegateCallArg so that it doesn't try to deactivate
cleanups for structs that have trivial destructors (cleanups for those
structs are never pushed to the cleanup stack in EmitParmDecl).

rdar://problem/39194693

Differential Revision: https://reviews.llvm.org/D45382

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@331020 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 0 deletions

diff --git a/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp b/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp
new file mode 100644
index 0000000000..87d21a3461
--- /dev/null
+++ b/test/CodeGenCXX/lambda-to-function-pointer-conversion.cpp
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -triple x86_64-pc-windows-msvc19.0.0 -std=c++11 -emit-llvm -o - %s | FileCheck %s
+
+// This code used to cause an assertion failure in EmitDelegateCallArg.
+
+// CHECK: define internal void @"?__invoke@<lambda_0>@?0??test@@YAXXZ@CA@UTrivial@@@Z"(
+// CHECK: call void @"??R<lambda_0>@?0??test@@YAXXZ@QEBA@UTrivial@@@Z"(
+
+// CHECK: define internal void @"??R<lambda_0>@?0??test@@YAXXZ@QEBA@UTrivial@@@Z"(
+
+struct Trivial {
+  int x;
+};
+
+void (*fnptr)(Trivial);
+
+void test() {
+  fnptr = [](Trivial a){ (void)a; };
+}