devtools/eigen
1
0
Fork 0
mirror of https://gitlab.com/libeigen/eigen.git synced 2026-04-10 11:34:33 +08:00
Code Issues Packages Projects Releases Wiki Activity

Re-implement move assignments.

Browse Source 
The original swap approach leads to potential undefined behavior (reading
uninitialized memory) and results in unnecessary copying of data for static
storage.

Here we pass down the move assignment to the underlying storage.  Static
storage does a one-way copy, dynamic storage does a swap.

Modified the tests to no longer read from the moved-from matrix/tensor,
since that can lead to UB. Added a test to ensure we do not access
uninitialized memory in a move.

Fixes: #2119
This commit is contained in:
Antonio Sanchez
2021-03-05 12:54:26 -08:00
committed by Rasmus Munk Larsen
parent b8d1857f0d
commit 543e34ab9d
8 changed files with 62 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
test/rvalue_types.cpp
View File

@@ -18,6 +18,36 @@
using internal::UIntPtr;
// A Scalar that asserts for uninitialized access.
template<typename T>
class SafeScalar {
public:
SafeScalar() : initialized_(false) {}
SafeScalar(const SafeScalar& other) {
*this = other;
}
SafeScalar& operator=(const SafeScalar& other) {
val_ = T(other);
initialized_ = true;
return *this;
}
SafeScalar(T val) : val_(val), initialized_(true) {}
SafeScalar& operator=(T val) {
val_ = val;
initialized_ = true;
}
operator T() const {
VERIFY(initialized_ && "Uninitialized access.");
return val_;
}
private:
T val_;
bool initialized_;
};
#if EIGEN_HAS_RVALUE_REFERENCES
template <typename MatrixType>
void rvalue_copyassign(const MatrixType& m)
@@ -94,19 +124,24 @@ void rvalue_move(const MatrixType& m)
MatrixType d = m;
VERIFY_IS_EQUAL(d, m);
// rvalue reference is moved
// rvalue reference is moved - copy constructor.
MatrixType e_src(m);
VERIFY_IS_EQUAL(e_src, m);
MatrixType e_dst(std::move(e_src));
VERIFY_IS_EQUAL(e_src, MatrixType());
VERIFY_IS_EQUAL(e_dst, m);
// rvalue reference is moved
// rvalue reference is moved - copy constructor.
MatrixType f_src(m);
VERIFY_IS_EQUAL(f_src, m);
MatrixType f_dst = std::move(f_src);
VERIFY_IS_EQUAL(f_src, MatrixType());
VERIFY_IS_EQUAL(f_dst, m);
// rvalue reference is moved - copy assignment.
MatrixType g_src(m);
VERIFY_IS_EQUAL(g_src, m);
MatrixType g_dst;
g_dst = std::move(g_src);
VERIFY_IS_EQUAL(g_dst, m);
}
#else
template <typename MatrixType>
@@ -144,6 +179,8 @@ EIGEN_DECLARE_TEST(rvalue_types)
#if EIGEN_HAS_CXX11
CALL_SUBTEST_5(rvalue_move(Eigen::Matrix<MovableScalar<float>,1,3>::Random().eval()));
CALL_SUBTEST_5(rvalue_move(Eigen::Matrix<SafeScalar<float>,1,3>::Random().eval()));
CALL_SUBTEST_5(rvalue_move(Eigen::Matrix<SafeScalar<float>,Eigen::Dynamic,Eigen::Dynamic>::Random(1,3).eval()));
#endif
}
}