Fix cleanup registration for lambda captures.

Lambda captures should be destroyed if an exception is thrown only if
the construction of the complete lambda-expression has not completed.
(If the lambda-expression has been fully constructed, any exception will
invoke its destructor, which will destroy the captures.)

This is directly modeled after how we handle the equivalent situation in
InitListExprs.

Note that EmitLambdaLValue was unreachable because in C++11 onwards the
frontend never creates the awkward situation where a prvalue expression
(such as a lambda) is used in an lvalue context (such as the left-hand
side of a class member access).

llvm-svn: 351487

1 files changed, 104 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/cxx1y-init-captures-eh.cpp b/clang/test/CodeGenCXX/cxx1y-init-captures-eh.cpp
new file mode 100644
index 00000000000..70103dccb15
--- /dev/null
+++ b/clang/test/CodeGenCXX/cxx1y-init-captures-eh.cpp
@@ -0,0 +1,104 @@
+// RUN: %clang_cc1 -std=c++1y -triple x86_64-linux-gnu -fexceptions -fcxx-exceptions -emit-llvm %s -o - | FileCheck %s
+
+struct S {
+  S();
+  ~S();
+};
+
+struct T {
+  T() noexcept;
+  ~T();
+  int n;
+};
+
+// CHECK-LABEL: define void @_Z1fv(
+void f() {
+  // CHECK: call void @_ZN1SC1Ev(
+  // CHECK: invoke void @__cxa_throw
+  //
+  // Ensure we call the lambda destructor here, and do not call the destructor
+  // for the capture.
+  // CHECK: landingpad
+  // CHECK-NOT: _ZN1SD
+  // CHECK: call void @"_ZZ1fvEN3$_0D1Ev"(
+  // CHECK-NOT: _ZN1SD
+  // CHECK: resume
+  [s = S()] {}, throw 0;
+
+  // CHECK: }
+}
+
+// CHECK-LABEL: define void @_Z1gv(
+void g() {
+  // CHECK: call void @_ZN1SC1Ev(
+  // CHECK: invoke void @__cxa_throw
+  //
+  // Ensure we call the lambda destructor here, and do not call the destructor
+  // for the capture.
+  // CHECK: landingpad
+  // CHECK-NOT: @"_ZZ1gvEN3$_0D1Ev"(
+  // CHECK: call void @_ZN1SD1Ev(
+  // CHECK-NOT: @"_ZZ1gvEN3$_0D1Ev"(
+  // CHECK: resume
+  [s = S(), t = (throw 0, 1)] {};
+
+  // CHECK: }
+}
+
+void x() noexcept;
+void y() noexcept;
+
+// CHECK-LABEL: define void @_Z1hbb(
+void h(bool b1, bool b2) {
+  // CHECK: {{.*}} = alloca i1,
+  // CHECK: %[[S_ISACTIVE:.*]] = alloca i1,
+  // CHECK: {{.*}} = alloca i1,
+
+  // lambda init: s and t, branch on b1
+  // CHECK: call void @_ZN1SC1Ev(
+  // CHECK: store i1 true, i1* %[[S_ISACTIVE]], align 1
+  // CHECK: call void @_ZN1TC1Ev(
+  // CHECK: br i1
+
+  // throw 1
+  // CHECK: invoke void @__cxa_throw
+
+  // completion of lambda init, branch on b2
+  // CHECK: store i32 42,
+  // CHECK: store i1 false, i1* %[[S_ISACTIVE]], align 1
+  // CHECK: br i1
+
+  // throw 2
+  // CHECK: invoke void @__cxa_throw
+
+  // end of full-expression
+  // CHECK: call void @_Z1xv(
+  // CHECK: call void @"_ZZ1hbbEN3$_2D1Ev"(
+  // CHECK: call void @_ZN1TD1Ev(
+  // CHECK: call void @_Z1yv(
+  // CHECK: ret void
+
+  // cleanups for throw 1
+  // CHECK: landingpad
+  // CHECK-NOT: @"_ZZ1hbbEN3$_2D1Ev"(
+  // CHECK: br
+
+  // cleanups for throw 2
+  // CHECK: landingpad
+  // CHECK: call void @"_ZZ1hbbEN3$_2D1Ev"(
+  // CHECK: br
+
+  // common cleanup code
+  // CHECK: call void @_ZN1TD1Ev(
+  // CHECK: load i1, i1* %[[S_ISACTIVE]],
+  // CHECK: br i1
+
+  // CHECK: call void @_ZN1SD1Ev(
+  // CHECK: br
+
+  // CHECK: resume
+  [s = S(), t = T().n, u = (b1 ? throw 1 : 42)] {}, (b2 ? throw 2 : 0), x();
+  y();
+
+  // CHECK: }
+}