Fix double destruction of objects when OpenMP construct is canceled

When an omp for loop is canceled the constructed objects are being destructed
twice.

It looks like the desired code is:

{

  Obj o;
  If (cancelled) branch-through-cleanups to cancel.exit.

}
[cleanups]
cancel.exit:

__kmpc_for_static_fini
br cancel.cont (*)

cancel.cont:

__kmpc_barrier
return

The problem seems to be the branch to cancel.cont is currently also going
through the cleanups calling them again. This change just does a direct branch
instead.

Patch By: michael.p.rice@intel.com

Differential Revision: https://reviews.llvm.org/D35854

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309288 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 2e31be8c6865bc6b9b279e26626373c70f401cd3..fed92a41a94b96d76841aa1d0a0b5f408faa3410 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1116,7 +1116,7 @@ private:
         auto IP = CGF.Builder.saveAndClearIP();
         CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
         CodeGen(CGF);
-        CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
+        CGF.EmitBranch(Stack.back().ContBlock.getBlock());
         CGF.Builder.restoreIP(IP);
         Stack.back().HasBeenEmitted = true;
       }

diff --git a/test/OpenMP/cancel_codegen_cleanup.cpp b/test/OpenMP/cancel_codegen_cleanup.cpp
new file mode 100644 (file)
index 0000000..5a297bd
--- /dev/null
+++ b/test/OpenMP/cancel_codegen_cleanup.cpp
@@ -0,0 +1,46 @@
+// RUN: %clang_cc1 -std=c++11 -fopenmp -fopenmp-version=45 -triple x86_64-apple-darwin13.4.0 -emit-llvm -o - %s | FileCheck %s
+
+//CHECK: call i32 @__kmpc_cancel
+//CHECK: br {{.*}}label %[[EXIT:[^,].+]], label %[[CONTINUE:.+]]
+//CHECK: [[EXIT]]:
+//CHECK: store i32 [[EXIT_SLOT:[0-9]+]]
+//CHECK: br label %[[CLEANUP:.+]]
+//CHECK: [[CONTINUE]]:
+//CHECK: store i32 [[CONT_SLOT:[0-9]+]],
+//CHECK: br label %[[CLEANUP]]
+//CHECK: [[CLEANUP]]:
+//CHECK-NEXT: call void @_ZN3ObjD1Ev
+//CHECK: switch i32{{.*}}, label %[[UNREACHABLE:.+]] [
+//CHECK:   i32 [[CONT_SLOT]], label %[[CLEANUPCONT:.+]]
+//CHECK:   i32 [[EXIT_SLOT]], label %[[CANCELEXIT:.+]]
+//CHECK-NEXT: ]
+//CHECK: [[CLEANUPCONT]]:
+//CHECK: br label %[[CANCELCONT:.+]]
+//CHECK: [[CANCELCONT]]:
+//CHECK-NEXT: call void @__kmpc_barrier(
+//CHECK-NEXT: ret void
+//CHECK: [[UNREACHABLE]]:
+//CHECK-NEXT: unreachable
+//CHECK-NEXT: }
+
+struct Obj {
+  int a; Obj(); Obj(const Obj& r) = delete; Obj &operator=(const Obj& r);
+  ~Obj();
+};
+ 
+void foo() {
+  int i,count = 0;
+  Obj obj;
+
+  #pragma omp parallel private(i) num_threads(1)
+  {
+      #pragma omp for reduction(+:count) lastprivate(obj)
+      for (i=0; i<1000; i++) {
+            if(i==100) {
+                obj.a = 100;
+                #pragma omp cancel for
+            }
+            count++;
+        }
+    }
+}