diff options
| -rw-r--r-- | lib/Support/StringMap.cpp | 2 | ||||
| -rw-r--r-- | unittests/ADT/StringMapTest.cpp | 22 |
2 files changed, 23 insertions, 1 deletions
diff --git a/lib/Support/StringMap.cpp b/lib/Support/StringMap.cpp index c131fe07f4..c2fc261df3 100644 --- a/lib/Support/StringMap.cpp +++ b/lib/Support/StringMap.cpp @@ -189,7 +189,7 @@ void StringMapImpl::RehashTable() { // grow/rehash the table. if (NumItems*4 > NumBuckets*3) { NewSize = NumBuckets*2; - } else if (NumBuckets-(NumItems+NumTombstones) < NumBuckets/8) { + } else if (NumBuckets-(NumItems+NumTombstones) <= NumBuckets/8) { NewSize = NumBuckets; } else { return; diff --git a/unittests/ADT/StringMapTest.cpp b/unittests/ADT/StringMapTest.cpp index 66e04933ad..5bb65cbd7a 100644 --- a/unittests/ADT/StringMapTest.cpp +++ b/unittests/ADT/StringMapTest.cpp @@ -134,6 +134,28 @@ TEST_F(StringMapTest, InsertAndEraseTest) { assertSingleItemMap(); } +TEST_F(StringMapTest, SmallFullMapTest) { + // StringMap has a tricky corner case when the map is small (<8 buckets) and + // it fills up through a balanced pattern of inserts and erases. This can + // lead to inf-loops in some cases (PR13148) so we test it explicitly here. + llvm::StringMap<int> Map(2); + + Map["eins"] = 1; + Map["zwei"] = 2; + Map["drei"] = 3; + Map.erase("drei"); + Map.erase("eins"); + Map["veir"] = 4; + Map["funf"] = 5; + + EXPECT_EQ(3u, Map.size()); + EXPECT_EQ(0, Map.lookup("eins")); + EXPECT_EQ(2, Map.lookup("zwei")); + EXPECT_EQ(0, Map.lookup("drei")); + EXPECT_EQ(4, Map.lookup("veir")); + EXPECT_EQ(5, Map.lookup("funf")); +} + // A more complex iteration test. TEST_F(StringMapTest, IterationTest) { bool visited[100]; |