llvm/unittests/ADT/DepthFirstIteratorTest.cpp
Tim Shen 3d515f61b6 [ADT] Actually mutate the iterator VisitStack.back().second, not its copy.
Summary: Before the change, *Opt never actually gets updated by the end
of toNext(), so for every next time the loop has to start over from
child_begin(). This bug doesn't affect the correctness, since Visited prevents
it from re-entering the same node again; but it's slow.

Reviewers: dberris, dblaikie, dannyb

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23649

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279482 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-22 21:59:26 +00:00

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//=== llvm/unittest/ADT/DepthFirstIteratorTest.cpp - DFS iterator tests ---===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "TestGraph.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace llvm {
template <typename T> struct CountedSet {
typedef typename SmallPtrSet<T, 4>::iterator iterator;
SmallPtrSet<T, 4> S;
int InsertVisited = 0;
std::pair<iterator, bool> insert(const T &Item) {
InsertVisited++;
return S.insert(Item);
}
size_t count(const T &Item) const { return S.count(Item); }
};
template <typename T> class df_iterator_storage<CountedSet<T>, true> {
public:
df_iterator_storage(CountedSet<T> &VSet) : Visited(VSet) {}
CountedSet<T> &Visited;
};
TEST(DepthFirstIteratorTest, ActuallyUpdateIterator) {
typedef CountedSet<Graph<3>::NodeType *> StorageT;
typedef df_iterator<Graph<3>, StorageT, true> DFIter;
Graph<3> G;
G.AddEdge(0, 1);
G.AddEdge(0, 2);
StorageT S;
for (auto N : make_range(DFIter::begin(G, S), DFIter::end(G, S)))
(void)N;
EXPECT_EQ(3, S.InsertVisited);
}
}