[CodeGen] Fix assertion on emitting cleanup for object with inlined inherited constructor and non-trivial destructor.

Fixes assertion
> Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast, file llvm/Support/Casting.h, line 255.

It was triggered by trying to cast `FunctionDecl` to `CXXMethodDecl` as
`CGF.CurCodeDecl` in `CallBaseDtor::Emit`. It was happening because
cleanups were emitted in `ScalarExprEmitter::VisitExprWithCleanups`
after destroying `InlinedInheritingConstructorScope`, so
`CodeGenFunction.CurCodeDecl` didn't correspond to expected cleanup decl.

Fix the assertion by emitting cleanups before leaving
`InlinedInheritingConstructorScope` and changing `CurCodeDecl`.

Test cases based on a patch by Shoaib Meenai.

Fixes PR36748.

rdar://problem/45805151

Reviewers: rsmith, rjmccall

Reviewed By: rjmccall

Subscribers: jkorous, dexonsmith, cfe-commits, smeenai, compnerd

Differential Revision: https://reviews.llvm.org/D55543

llvm-svn: 349848

1 files changed, 52 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/inheriting-constructor-cleanup.cpp b/clang/test/CodeGenCXX/inheriting-constructor-cleanup.cpp
new file mode 100644
index 00000000000..3aac9ac9f78
--- /dev/null
+++ b/clang/test/CodeGenCXX/inheriting-constructor-cleanup.cpp
@@ -0,0 +1,52 @@
+// RUN: %clang_cc1 -triple x86_64-darwin -std=c++11 -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-darwin -std=c++11 -fcxx-exceptions -fexceptions -emit-llvm -o - %s | FileCheck %s --check-prefix=EXCEPTIONS
+
+// PR36748
+// rdar://problem/45805151
+
+// Classes to verify order of destroying function parameters.
+struct S1 {
+  ~S1();
+};
+struct S2 {
+  ~S2();
+};
+
+struct Base {
+  // Use variadic args to cause inlining the inherited constructor.
+  Base(const S1&, const S2&, const char *fmt, ...) {}
+};
+
+struct NonTrivialDtor {
+  ~NonTrivialDtor() {}
+};
+struct Inheritor : public NonTrivialDtor, public Base {
+  using Base::Base;
+};
+
+void f() {
+  Inheritor(S1(), S2(), "foo");
+  // CHECK-LABEL: define void @_Z1fv
+  // CHECK: %[[TMP1:.*]] = alloca %struct.S1
+  // CHECK: %[[TMP2:.*]] = alloca %struct.S2
+  // CHECK: call void (%struct.Base*, %struct.S1*, %struct.S2*, i8*, ...) @_ZN4BaseC2ERK2S1RK2S2PKcz(%struct.Base* {{.*}}, %struct.S1* dereferenceable(1) %[[TMP1]], %struct.S2* dereferenceable(1) %[[TMP2]], i8* {{.*}})
+  // CHECK-NEXT: call void @_ZN9InheritorD1Ev(%struct.Inheritor* {{.*}})
+  // CHECK-NEXT: call void @_ZN2S2D1Ev(%struct.S2* %[[TMP2]])
+  // CHECK-NEXT: call void @_ZN2S1D1Ev(%struct.S1* %[[TMP1]])
+
+  // EXCEPTIONS-LABEL: define void @_Z1fv
+  // EXCEPTIONS: %[[TMP1:.*]] = alloca %struct.S1
+  // EXCEPTIONS: %[[TMP2:.*]] = alloca %struct.S2
+  // EXCEPTIONS: invoke void (%struct.Base*, %struct.S1*, %struct.S2*, i8*, ...) @_ZN4BaseC2ERK2S1RK2S2PKcz(%struct.Base* {{.*}}, %struct.S1* dereferenceable(1) %[[TMP1]], %struct.S2* dereferenceable(1) %[[TMP2]], i8* {{.*}})
+  // EXCEPTIONS-NEXT: to label %[[CONT:.*]] unwind label %[[LPAD:.*]]
+
+  // EXCEPTIONS: [[CONT]]:
+  // EXCEPTIONS-NEXT: call void @_ZN9InheritorD1Ev(%struct.Inheritor* {{.*}})
+  // EXCEPTIONS-NEXT: call void @_ZN2S2D1Ev(%struct.S2* %[[TMP2]])
+  // EXCEPTIONS-NEXT: call void @_ZN2S1D1Ev(%struct.S1* %[[TMP1]])
+
+  // EXCEPTIONS: [[LPAD]]:
+  // EXCEPTIONS: call void @_ZN14NonTrivialDtorD2Ev(%struct.NonTrivialDtor* {{.*}})
+  // EXCEPTIONS-NEXT: call void @_ZN2S2D1Ev(%struct.S2* %[[TMP2]])
+  // EXCEPTIONS-NEXT: call void @_ZN2S1D1Ev(%struct.S1* %[[TMP1]])
+}