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author | Owen Anderson <resistor@mac.com> | 2011-07-06 22:36:59 +0000 |
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committer | Owen Anderson <resistor@mac.com> | 2011-07-06 22:36:59 +0000 |
commit | 9cbd7afb76f20ce874464c238764c54f86b3ce3b (patch) | |
tree | 7acc01733408ee1b1164841128edad753982669e /unittests | |
parent | 4fd3c5957e6a272b60d6446e745136187d07f812 (diff) | |
download | external_llvm-9cbd7afb76f20ce874464c238764c54f86b3ce3b.zip external_llvm-9cbd7afb76f20ce874464c238764c54f86b3ce3b.tar.gz external_llvm-9cbd7afb76f20ce874464c238764c54f86b3ce3b.tar.bz2 |
Fix a subtle issue in SmallVector. The following code did not work as expected:
vec.insert(vec.begin(), vec[3]);
The issue was that vec[3] returns a reference into the vector, which is invalidated when insert() memmove's the elements down to make space. The method needs to specifically detect and handle this case to correctly match std::vector's semantics.
Thanks to Howard Hinnant for clarifying the correct behavior, and explaining how std::vector solves this problem.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134554 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'unittests')
-rw-r--r-- | unittests/ADT/SmallVectorTest.cpp | 48 |
1 files changed, 27 insertions, 21 deletions
diff --git a/unittests/ADT/SmallVectorTest.cpp b/unittests/ADT/SmallVectorTest.cpp index f4da54d..0d3535d 100644 --- a/unittests/ADT/SmallVectorTest.cpp +++ b/unittests/ADT/SmallVectorTest.cpp @@ -35,26 +35,26 @@ public: Constructable() : value(0) { ++numConstructorCalls; } - + Constructable(int val) : value(val) { ++numConstructorCalls; } - + Constructable(const Constructable & src) { value = src.value; ++numConstructorCalls; } - + ~Constructable() { ++numDestructorCalls; } - + Constructable & operator=(const Constructable & src) { value = src.value; ++numAssignmentCalls; return *this; } - + int getValue() const { return abs(value); } @@ -64,7 +64,7 @@ public: numDestructorCalls = 0; numAssignmentCalls = 0; } - + static int getNumConstructorCalls() { return numConstructorCalls; } @@ -91,10 +91,10 @@ int Constructable::numAssignmentCalls; class SmallVectorTest : public testing::Test { protected: typedef SmallVector<Constructable, 4> VectorType; - + VectorType theVector; VectorType otherVector; - + void SetUp() { Constructable::reset(); } @@ -111,7 +111,7 @@ protected: // Assert that theVector contains the specified values, in order. void assertValuesInOrder(VectorType & v, size_t size, ...) { EXPECT_EQ(size, v.size()); - + va_list ap; va_start(ap, size); for (size_t i = 0; i < size; ++i) { @@ -121,7 +121,7 @@ protected: va_end(ap); } - + // Generate a sequence of values to initialize the vector. void makeSequence(VectorType & v, int start, int end) { for (int i = start; i <= end; ++i) { @@ -155,18 +155,24 @@ TEST_F(SmallVectorTest, PushPopTest) { theVector.push_back(Constructable(2)); assertValuesInOrder(theVector, 2u, 1, 2); + // Insert at beginning + theVector.insert(theVector.begin(), theVector[1]); + assertValuesInOrder(theVector, 3u, 2, 1, 2); + // Pop one element theVector.pop_back(); - assertValuesInOrder(theVector, 1u, 1); + assertValuesInOrder(theVector, 2u, 2, 1); - // Pop another element + // Pop remaining elements + theVector.pop_back(); theVector.pop_back(); assertEmpty(theVector); - + // Check number of constructor calls. Should be 2 for each list element, - // one for the argument to push_back, and one for the list element itself. - EXPECT_EQ(4, Constructable::getNumConstructorCalls()); - EXPECT_EQ(4, Constructable::getNumDestructorCalls()); + // one for the argument to push_back, one for the argument to insert, + // and one for the list element itself. + EXPECT_EQ(5, Constructable::getNumConstructorCalls()); + EXPECT_EQ(5, Constructable::getNumDestructorCalls()); } // Clear test. @@ -198,7 +204,7 @@ TEST_F(SmallVectorTest, ResizeGrowTest) { SCOPED_TRACE("ResizeGrowTest"); theVector.resize(2); - + // The extra constructor/destructor calls come from the temporary object used // to initialize the contents of the resized array (via copy construction). EXPECT_EQ(3, Constructable::getNumConstructorCalls()); @@ -226,10 +232,10 @@ TEST_F(SmallVectorTest, OverflowTest) { for (int i = 0; i < 10; ++i) { EXPECT_EQ(i+1, theVector[i].getValue()); } - + // Now resize back to fixed size. theVector.resize(1); - + assertValuesInOrder(theVector, 1u, 1); } @@ -364,13 +370,13 @@ TEST_F(SmallVectorTest, ComparisonTest) { makeSequence(theVector, 1, 3); makeSequence(otherVector, 1, 3); - + EXPECT_TRUE(theVector == otherVector); EXPECT_FALSE(theVector != otherVector); otherVector.clear(); makeSequence(otherVector, 2, 4); - + EXPECT_FALSE(theVector == otherVector); EXPECT_TRUE(theVector != otherVector); } |