r184475 - Call __cxa_begin_catch before std::terminate() in a noexcept trap.

John McCall rjmccall at apple.com
Thu Jun 20 14:37:44 PDT 2013


Author: rjmccall
Date: Thu Jun 20 16:37:43 2013
New Revision: 184475

URL: http://llvm.org/viewvc/llvm-project?rev=184475&view=rev
Log:
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.

Added:
    cfe/trunk/test/CodeGenCXX/noexcept.cpp
Modified:
    cfe/trunk/lib/CodeGen/CGException.cpp

Modified: cfe/trunk/lib/CodeGen/CGException.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGException.cpp?rev=184475&r1=184474&r2=184475&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGException.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGException.cpp Thu Jun 20 16:37:43 2013
@@ -1619,8 +1619,15 @@ llvm::BasicBlock *CodeGenFunction::getTe
   // 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.

Added: cfe/trunk/test/CodeGenCXX/noexcept.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/noexcept.cpp?rev=184475&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/noexcept.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/noexcept.cpp Thu Jun 20 16:37:43 2013
@@ -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





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