[llvm] r344542 - [ADT] Fix a bug in DenseSet's initializer_list constructor.

[Lang Hames via llvm-commits]

Author: lhames
Date: Mon Oct 15 11:34:36 2018
New Revision: 344542

URL: http://llvm.org/viewvc/llvm-project?rev=344542&view=rev
Log:
[ADT] Fix a bug in DenseSet's initializer_list constructor.

Without this fix, DenseSet crashes with an assertion if constructed with an
initializer_list whose length is not a power of two.

Modified:
    llvm/trunk/include/llvm/ADT/DenseSet.h
    llvm/trunk/unittests/ADT/DenseSetTest.cpp

Modified: llvm/trunk/include/llvm/ADT/DenseSet.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/DenseSet.h?rev=344542&r1=344541&r2=344542&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/DenseSet.h (original)
+++ llvm/trunk/include/llvm/ADT/DenseSet.h Mon Oct 15 11:34:36 2018
@@ -16,6 +16,7 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseMapInfo.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/type_traits.h"
 #include <algorithm>
 #include <cstddef>
@@ -67,7 +68,7 @@ public:
   explicit DenseSetImpl(unsigned InitialReserve = 0) : TheMap(InitialReserve) {}
 
   DenseSetImpl(std::initializer_list<ValueT> Elems)
-      : DenseSetImpl(Elems.size()) {
+      : DenseSetImpl(PowerOf2Ceil(Elems.size())) {
     insert(Elems.begin(), Elems.end());
   }
 

Modified: llvm/trunk/unittests/ADT/DenseSetTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/DenseSetTest.cpp?rev=344542&r1=344541&r2=344542&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/DenseSetTest.cpp (original)
+++ llvm/trunk/unittests/ADT/DenseSetTest.cpp Mon Oct 15 11:34:36 2018
@@ -80,6 +80,14 @@ TYPED_TEST(DenseSetTest, InitializerList
   EXPECT_EQ(0u, set.count(3));
 }
 
+TYPED_TEST(DenseSetTest, InitializerListWithNonPowerOfTwoLength) {
+  TypeParam set({1, 2, 3});
+  EXPECT_EQ(3u, set.size());
+  EXPECT_EQ(1u, set.count(1));
+  EXPECT_EQ(1u, set.count(2));
+  EXPECT_EQ(1u, set.count(3));
+}
+
 TYPED_TEST(DenseSetTest, ConstIteratorComparison) {
   TypeParam set({1});
   const TypeParam &cset = set;