From 45ff3807ef06bca715afb9eb7e16c4c89880e40e Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Thu, 20 Jun 2013 21:37:43 +0000
Subject: [PATCH] Call __cxa_begin_catch before std::terminate() in a noexcept
 trap.

r174939-40 caused us to do this in the canonical terminate lpad,
but when the EH stack has other cleanups on it we use the
terminate handler block, which wasn't doing this.

Fixes the rest of rdar://11904428 given appropriate stdlib support.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184475 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGException.cpp  | 11 ++++++--
 test/CodeGenCXX/noexcept.cpp | 49 ++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 2 deletions(-)
 create mode 100644 test/CodeGenCXX/noexcept.cpp

diff --git a/lib/CodeGen/CGException.cpp b/lib/CodeGen/CGException.cpp
index 4b09e97344..b01fdd4b26 100644
--- a/lib/CodeGen/CGException.cpp
+++ b/lib/CodeGen/CGException.cpp
@@ -1619,8 +1619,15 @@ llvm::BasicBlock *CodeGenFunction::getTerminateHandler() {
   // end of the function by FinishFunction.
   TerminateHandler = createBasicBlock("terminate.handler");
   Builder.SetInsertPoint(TerminateHandler);
-  llvm::CallInst *TerminateCall = EmitNounwindRuntimeCall(getTerminateFn(CGM));
-  TerminateCall->setDoesNotReturn();
+  llvm::CallInst *terminateCall;
+  if (useClangCallTerminate(CGM)) {
+    // Load the exception pointer.
+    llvm::Value *exn = getExceptionFromSlot();
+    terminateCall = EmitNounwindRuntimeCall(getClangCallTerminateFn(CGM), exn);
+  } else {
+    terminateCall = EmitNounwindRuntimeCall(getTerminateFn(CGM));
+  }
+  terminateCall->setDoesNotReturn();
   Builder.CreateUnreachable();
 
   // Restore the saved insertion state.
diff --git a/test/CodeGenCXX/noexcept.cpp b/test/CodeGenCXX/noexcept.cpp
new file mode 100644
index 0000000000..4ee149ed8d
--- /dev/null
+++ b/test/CodeGenCXX/noexcept.cpp
@@ -0,0 +1,49 @@
+// RUN: %clang_cc1 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - -fcxx-exceptions -fexceptions -std=c++11 | FileCheck %s
+
+// rdar://11904428
+//   Ensure that we call __cxa_begin_catch before calling
+//   std::terminate in a noexcept function.
+namespace test0 {
+  void foo();
+
+  struct A {
+    A();
+    ~A();
+  };
+
+  void test() noexcept {
+    A a;
+    foo();
+  }
+}
+// CHECK:    define void @_ZN5test04testEv()
+// CHECK:      [[EXN:%.*]] = alloca i8*
+//   This goes to the terminate lpad.
+// CHECK:      invoke void @_ZN5test01AC1Ev(
+//   This goes to the cleanup-and-then-terminate lpad.
+// CHECK:      invoke void @_ZN5test03fooEv()
+//   Destructors don't throw by default in C++11.
+// CHECK:      call void @_ZN5test01AD1Ev(
+//   Cleanup lpad.
+// CHECK:      [[T0:%.*]] = landingpad
+// CHECK-NEXT:   catch i8* null
+// CHECK-NEXT: [[T1:%.*]] = extractvalue { i8*, i32 } [[T0]], 0
+// CHECK-NEXT: store i8* [[T1]], i8** [[EXN]]
+//   (Calling this destructor is not technically required.)
+// CHECK:      call void @_ZN5test01AD1Ev(
+// CHECK-NEXT: br label
+//   The terminate landing pad jumps in here for some reason.
+// CHECK:      [[T0:%.*]] = landingpad
+// CHECK-NEXT:   catch i8* null
+// CHECK-NEXT: [[T1:%.*]] = extractvalue { i8*, i32 } [[T0]], 0
+// CHECK-NEXT: call void @__clang_call_terminate(i8* [[T1]])
+// CHECK-NEXT: unreachable
+//   The terminate handler chained to by the cleanup lpad.
+// CHECK:      [[T0:%.*]] = load i8** [[EXN]]
+// CHECK-NEXT: call void @__clang_call_terminate(i8* [[T0]])
+// CHECK-NEXT: unreachable
+
+// CHECK:  define linkonce_odr hidden void @__clang_call_terminate(
+// CHECK:      call i8* @__cxa_begin_catch(
+// CHECK-NEXT: call void @_ZSt9terminatev()
+// CHECK-NEXT: unreachable
-- 
2.40.0