Make sure we don't emit IR for unused EH cleanups. PR13359.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161148 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 28 insertions, 2 deletions

diff --git a/lib/CodeGen/CGCleanup.cpp b/lib/CodeGen/CGCleanup.cpp
index b00e2a21bf..f9ea7e0a26 100644
--- a/lib/CodeGen/CGCleanup.cpp
+++ b/lib/CodeGen/CGCleanup.cpp
@@ -831,8 +831,12 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
 
     EmitBlock(EHEntry);
 
-    cleanupFlags.setIsForEHCleanup();
-    EmitCleanup(*this, Fn, cleanupFlags, EHActiveFlag);
+    // We only actually emit the cleanup code if the cleanup is either
+    // active or was used before it was deactivated.
+    if (EHActiveFlag || IsActive) {
+      cleanupFlags.setIsForEHCleanup();
+      EmitCleanup(*this, Fn, cleanupFlags, EHActiveFlag);
+    }
 
     Builder.CreateBr(getEHDispatchBlock(EHParent));
 
diff --git a/test/CodeGenCXX/throw-expression-cleanup.cpp b/test/CodeGenCXX/throw-expression-cleanup.cpp
new file mode 100644
index 0000000000..0c41bc65bc
--- /dev/null
+++ b/test/CodeGenCXX/throw-expression-cleanup.cpp
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 %s -emit-llvm -fcxx-exceptions -fexceptions -std=c++11 -o - | FileCheck %s
+// PR13359
+
+struct X {
+  ~X();
+};
+struct Error {
+  Error(const X&) noexcept;
+};
+
+void f() {
+  try {
+    throw Error(X());
+  } catch (...) { }
+}
+
+// CHECK: define void @_Z1fv
+// CHECK: call void @_ZN5ErrorC1ERK1X
+// CHECK: invoke void @__cxa_throw
+// CHECK: landingpad
+// CHECK: call void @_ZN1XD1Ev
+// CHECK-NOT: __cxa_free_exception