Greetings,
This patch adds a lightweight self-consistency check to many vector
operations. Google issue 5246356.
Ok for google/integration branch?
Thanks,
--
2011-09-06 Paul Pluzhnikov <ppluzhni...@google.com>
* include/bits/stl_vector.h (__is_valid): New function.
(begin, end, size, capacity, swap, clear): Call it.
* include/bits/vector.tcc (operator=): Likewise.
Index: include/bits/stl_vector.h
===================================================================
--- include/bits/stl_vector.h (revision 178493)
+++ include/bits/stl_vector.h (working copy)
@@ -234,6 +234,16 @@
using _Base::_M_impl;
using _Base::_M_get_Tp_allocator;
+ bool __is_valid() const
+ {
+ return (this->_M_impl._M_end_of_storage == 0
+ && this->_M_impl._M_start == 0
+ && this->_M_impl._M_finish == 0)
+ || (this->_M_impl._M_start <= this->_M_impl._M_finish
+ && this->_M_impl._M_finish <= this->_M_impl._M_end_of_storage
+ && this->_M_impl._M_start < this->_M_impl._M_end_of_storage);
+ }
+
public:
// [23.2.4.1] construct/copy/destroy
// (assign() and get_allocator() are also listed in this section)
@@ -531,7 +541,13 @@
*/
iterator
begin() _GLIBCXX_NOEXCEPT
- { return iterator(this->_M_impl._M_start); }
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("begin() on corrupt (dangling?) vector");
+#endif
+ return iterator(this->_M_impl._M_start);
+ }
/**
* Returns a read-only (constant) iterator that points to the
@@ -540,7 +556,13 @@
*/
const_iterator
begin() const _GLIBCXX_NOEXCEPT
- { return const_iterator(this->_M_impl._M_start); }
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("begin() on corrupt (dangling?) vector");
+#endif
+ return const_iterator(this->_M_impl._M_start);
+ }
/**
* Returns a read/write iterator that points one past the last
@@ -549,7 +571,13 @@
*/
iterator
end() _GLIBCXX_NOEXCEPT
- { return iterator(this->_M_impl._M_finish); }
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("end() on corrupt (dangling?) vector");
+#endif
+ return iterator(this->_M_impl._M_finish);
+ }
/**
* Returns a read-only (constant) iterator that points one past
@@ -558,7 +586,13 @@
*/
const_iterator
end() const _GLIBCXX_NOEXCEPT
- { return const_iterator(this->_M_impl._M_finish); }
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("end() on corrupt (dangling?) vector");
+#endif
+ return const_iterator(this->_M_impl._M_finish);
+ }
/**
* Returns a read/write reverse iterator that points to the
@@ -638,7 +672,13 @@
/** Returns the number of elements in the %vector. */
size_type
size() const _GLIBCXX_NOEXCEPT
- { return size_type(this->_M_impl._M_finish - this->_M_impl._M_start); }
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("size() on corrupt (dangling?) vector");
+#endif
+ return size_type(this->_M_impl._M_finish - this->_M_impl._M_start);
+ }
/** Returns the size() of the largest possible %vector. */
size_type
@@ -718,7 +758,12 @@
*/
size_type
capacity() const _GLIBCXX_NOEXCEPT
- { return size_type(this->_M_impl._M_end_of_storage
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("capacity() on corrupt (dangling?) vector");
+#endif
+ return size_type(this->_M_impl._M_end_of_storage
- this->_M_impl._M_start); }
/**
@@ -1112,6 +1157,10 @@
noexcept(_Alloc_traits::_S_nothrow_swap())
#endif
{
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid() || !__x.__is_valid())
+ __throw_logic_error("swap() on corrupt (dangling?) vector");
+#endif
this->_M_impl._M_swap_data(__x._M_impl);
_Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
__x._M_get_Tp_allocator());
@@ -1125,7 +1174,13 @@
*/
void
clear() _GLIBCXX_NOEXCEPT
- { _M_erase_at_end(this->_M_impl._M_start); }
+ {
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid())
+ __throw_logic_error("clear() on corrupt (dangling?) vector");
+#endif
+ _M_erase_at_end(this->_M_impl._M_start);
+ }
protected:
/**
Index: include/bits/vector.tcc
===================================================================
--- include/bits/vector.tcc (revision 178493)
+++ include/bits/vector.tcc (working copy)
@@ -158,6 +158,10 @@
vector<_Tp, _Alloc>::
operator=(const vector<_Tp, _Alloc>& __x)
{
+#if __google_stl_debug_dangling_vector
+ if (!this->__is_valid() || !__x.__is_valid())
+ __throw_logic_error("operator=() on corrupt (dangling?) vector");
+#endif
if (&__x != this)
{
#ifdef __GXX_EXPERIMENTAL_CXX0X__
--
This patch is available for review at http://codereview.appspot.com/4973065
