Fix http://llvm.org/PR5160, to let CallbackVHs modify other ValueHandles on the
same Value without breaking things.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83861 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Support/ValueHandleTest.cpp b/unittests/Support/ValueHandleTest.cpp
index c6b5356..c89a7af 100644
--- a/unittests/Support/ValueHandleTest.cpp
+++ b/unittests/Support/ValueHandleTest.cpp
@@ -11,6 +11,7 @@
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
+#include "llvm/ADT/OwningPtr.h"
#include "gtest/gtest.h"
@@ -327,4 +328,84 @@
BitcastUser->getOperand(0));
}
+TEST_F(ValueHandle, DestroyingOtherVHOnSameValueDoesntBreakIteration) {
+ // When a CallbackVH modifies other ValueHandles in its callbacks,
+ // that shouldn't interfere with non-modified ValueHandles receiving
+ // their appropriate callbacks.
+ //
+ // We create the active CallbackVH in the middle of a palindromic
+ // arrangement of other VHs so that the bad behavior would be
+ // triggered in whichever order callbacks run.
+
+ class DestroyingVH : public CallbackVH {
+ public:
+ OwningPtr<WeakVH> ToClear[2];
+ DestroyingVH(Value *V) {
+ ToClear[0].reset(new WeakVH(V));
+ setValPtr(V);
+ ToClear[1].reset(new WeakVH(V));
+ }
+ virtual void deleted() {
+ ToClear[0].reset();
+ ToClear[1].reset();
+ CallbackVH::deleted();
+ }
+ virtual void allUsesReplacedWith(Value *) {
+ ToClear[0].reset();
+ ToClear[1].reset();
+ }
+ };
+
+ {
+ WeakVH ShouldBeVisited1(BitcastV.get());
+ DestroyingVH C(BitcastV.get());
+ WeakVH ShouldBeVisited2(BitcastV.get());
+
+ BitcastV->replaceAllUsesWith(ConstantV);
+ EXPECT_EQ(ConstantV, static_cast<Value*>(ShouldBeVisited1));
+ EXPECT_EQ(ConstantV, static_cast<Value*>(ShouldBeVisited2));
+ }
+
+ {
+ WeakVH ShouldBeVisited1(BitcastV.get());
+ DestroyingVH C(BitcastV.get());
+ WeakVH ShouldBeVisited2(BitcastV.get());
+
+ BitcastV.reset();
+ EXPECT_EQ(NULL, static_cast<Value*>(ShouldBeVisited1));
+ EXPECT_EQ(NULL, static_cast<Value*>(ShouldBeVisited2));
+ }
+}
+
+TEST_F(ValueHandle, AssertingVHCheckedLast) {
+ // If a CallbackVH exists to clear out a group of AssertingVHs on
+ // Value deletion, the CallbackVH should get a chance to do so
+ // before the AssertingVHs assert.
+
+ class ClearingVH : public CallbackVH {
+ public:
+ AssertingVH<Value> *ToClear[2];
+ ClearingVH(Value *V,
+ AssertingVH<Value> &A0, AssertingVH<Value> &A1)
+ : CallbackVH(V) {
+ ToClear[0] = &A0;
+ ToClear[1] = &A1;
+ }
+
+ virtual void deleted() {
+ *ToClear[0] = 0;
+ *ToClear[1] = 0;
+ CallbackVH::deleted();
+ }
+ };
+
+ AssertingVH<Value> A1, A2;
+ A1 = BitcastV.get();
+ ClearingVH C(BitcastV.get(), A1, A2);
+ A2 = BitcastV.get();
+ // C.deleted() should run first, clearing the two AssertingVHs,
+ // which should prevent them from asserting.
+ BitcastV.reset();
+}
+
}