PR 90904 notes that auto_vec is unsafe to copy and assign because
the class manages its own memory but doesn't define (or delete)
either special function. Since I first ran into the problem,
auto_vec has grown a move ctor and move assignment from
a dynamically-allocated vec but still no copy ctor or copy
assignment operator.
The attached patch adds the two special functions to auto_vec along
with a few simple tests. It makes auto_vec safe to use in containers
that expect copyable and assignable element types and passes bootstrap
and regression testing on x86_64-linux.
Martin
PR middle-end/90904 - vec assignment and copying undefined
gcc/ChangeLog:
* vec.c (test_copy_assign): New function.
(vec_c_tests): Call it.
* vec.h (auto_vec copy ctor): Define.
(auto_vec::operator=): Define.
diff --git a/gcc/vec.c b/gcc/vec.c
index f9dbb2cac31..c9299875257 100644
--- a/gcc/vec.c
+++ b/gcc/vec.c
@@ -317,6 +317,83 @@ test_safe_push ()
ASSERT_EQ (7, v[2]);
}
+/* Verify that auto_vec copy ctor and assignment work correctly. */
+
+static void
+test_copy_assign ()
+{
+ auto_vec <int> a0;
+ auto_vec <int> b0 (0);
+ auto_vec <int> c0 (7);
+ ASSERT_EQ (0, b0.length ());
+ ASSERT_EQ (0, c0.length ());
+
+ a0 = a0;
+ ASSERT_EQ (0, a0.length ());
+ b0 = a0;
+ ASSERT_EQ (0, b0.length ());
+ c0 = a0;
+ ASSERT_EQ (0, c0.length ());
+
+ auto_vec <int> a3;
+ a3.safe_push (5);
+ a3.safe_push (6);
+ a3.safe_push (7);
+
+ auto_vec <int> b3 (a3);
+ ASSERT_EQ (3, b3.length ());
+ ASSERT_EQ (5, b3[0]);
+ ASSERT_EQ (6, b3[1]);
+ ASSERT_EQ (7, b3[2]);
+
+ auto_vec <int> c3;
+ c3 = b3;
+ ASSERT_EQ (3, c3.length ());
+ ASSERT_EQ (5, c3[0]);
+ ASSERT_EQ (6, c3[1]);
+ ASSERT_EQ (7, c3[2]);
+
+ auto_vec <int> d4;
+ d4.safe_push (1);
+ d4.safe_push (2);
+ d4.safe_push (3);
+ d4.safe_push (4);
+
+ c3 = d4;
+ ASSERT_EQ (4, c3.length ());
+ ASSERT_EQ (1, c3[0]);
+ ASSERT_EQ (2, c3[1]);
+ ASSERT_EQ (3, c3[2]);
+ ASSERT_EQ (4, c3[3]);
+
+ d4 = a3;
+ ASSERT_EQ (3, d4.length ());
+ ASSERT_EQ (5, d4[0]);
+ ASSERT_EQ (6, d4[1]);
+ ASSERT_EQ (7, d4[2]);
+
+ a3 = b0;
+ ASSERT_EQ (0, a3.length ());
+
+ b3 = b0;
+ ASSERT_EQ (0, b3.length ());
+
+ c3 = c0;
+ ASSERT_EQ (0, c3.length ());
+
+ b0 = d4;
+ ASSERT_EQ (3, b0.length ());
+ ASSERT_EQ (5, b0[0]);
+ ASSERT_EQ (6, b0[1]);
+ ASSERT_EQ (7, b0[2]);
+
+ c0 = d4;
+ ASSERT_EQ (3, c0.length ());
+ ASSERT_EQ (5, c0[0]);
+ ASSERT_EQ (6, c0[1]);
+ ASSERT_EQ (7, c0[2]);
+}
+
/* Verify that vec::truncate works correctly. */
static void
@@ -549,6 +626,7 @@ vec_c_tests ()
{
test_quick_push ();
test_safe_push ();
+ test_copy_assign ();
test_truncate ();
test_safe_grow_cleared ();
test_pop ();
diff --git a/gcc/vec.h b/gcc/vec.h
index 24df2db0eeb..61397bb7ee0 100644
--- a/gcc/vec.h
+++ b/gcc/vec.h
@@ -1551,12 +1551,21 @@ public:
auto_vec (size_t n CXX_MEM_STAT_INFO) { this->create (n PASS_MEM_STAT); }
~auto_vec () { this->release (); }
+ /* Copy ctor. */
+ auto_vec (const auto_vec&);
+
+ /* Move ctor from a heap-allocated vec. */
auto_vec (vec<T, va_heap>&& r)
{
gcc_assert (!r.using_auto_storage ());
this->m_vec = r.m_vec;
r.m_vec = NULL;
}
+
+ /* Copy asssignment. */
+ auto_vec& operator= (const auto_vec&);
+
+ /* Move asssignment from a heap-allocated vec. */
auto_vec& operator= (vec<T, va_heap>&& r)
{
gcc_assert (!r.using_auto_storage ());
@@ -1567,6 +1576,49 @@ public:
}
};
+/* Copy elements from R to *THIS. */
+
+template<typename T>
+auto_vec<T, 0>::auto_vec (const auto_vec& r)
+{
+ const unsigned n = r.length ();
+ this->create (n);
+ if (n)
+ {
+ vec_copy_construct (this->address (), r.address (), n);
+ this->m_vec->m_vecpfx.m_num = n;
+ }
+}
+
+/* Assign elements from R over *THIS, invoking the copy assignment
+ operator on the initial elements and the copy ctor on the excess. */
+
+template<typename T>
+auto_vec<T, 0>& auto_vec<T, 0>::operator= (const auto_vec& r)
+{
+ unsigned n0 = this->length ();
+ const unsigned n1 = r.length ();
+ if (n0 < n1)
+ this->safe_grow (n1);
+ else
+ {
+ this->truncate (n1);
+ n0 = n1;
+ }
+
+ T *dst = this->address ();
+ const T *src = r.address ();
+
+ /* Copy-assign over the first N0 elements. */
+ for (unsigned i = 0; i != n0; ++i)
+ dst[i] = src[i];
+
+ if (n0 < n1)
+ /* Copy-construct elements in excess of N0. */
+ vec_copy_construct (dst + n0, src + n0, n1 - n0);
+
+ return *this;
+}
/* Allocate heap memory for pointer V and create the internal vector
with space for NELEMS elements. If NELEMS is 0, the internal
