libstdc++: Avoid bogus warning in std::vector::insert [PR107852]
GCC assumes that any global variable might be modified by operator new, and so in the testcase for this PR all data members get reloaded after allocating new storage. By making local copies of the _M_start and _M_finish members we avoid that, and then the compiler has enough info to remove the dead branches that trigger bogus -Warray-bounds warnings. libstdc++-v3/ChangeLog: PR libstdc++/107852 PR libstdc++/106199 PR libstdc++/100366 * include/bits/vector.tcc (vector::_M_fill_insert): Copy _M_start and _M_finish members before allocating. (vector::_M_default_append): Likewise. (vector::_M_range_insert): Likewise.
This commit is contained in:
Jonathan Wakely
parent
81cf0354d5
commit
cca06f0d6d
1 changed files with 37 additions and 26 deletions
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@ -539,9 +539,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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if (__elems_after > __n)
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{
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_GLIBCXX_ASAN_ANNOTATE_GROW(__n);
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std::__uninitialized_move_a(this->_M_impl._M_finish - __n,
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this->_M_impl._M_finish,
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this->_M_impl._M_finish,
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std::__uninitialized_move_a(__old_finish - __n,
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__old_finish,
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__old_finish,
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_M_get_Tp_allocator());
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this->_M_impl._M_finish += __n;
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_GLIBCXX_ASAN_ANNOTATE_GREW(__n);
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@ -554,7 +554,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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{
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_GLIBCXX_ASAN_ANNOTATE_GROW(__n);
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this->_M_impl._M_finish =
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std::__uninitialized_fill_n_a(this->_M_impl._M_finish,
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std::__uninitialized_fill_n_a(__old_finish,
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__n - __elems_after,
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__x_copy,
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_M_get_Tp_allocator());
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@ -569,9 +569,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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}
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else
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{
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// Make local copies of these members because the compiler thinks
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// the allocator can alter them if 'this' is globally reachable.
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pointer __old_start = this->_M_impl._M_start;
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pointer __old_finish = this->_M_impl._M_finish;
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const pointer __pos = __position.base();
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const size_type __len =
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_M_check_len(__n, "vector::_M_fill_insert");
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const size_type __elems_before = __position - begin();
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const size_type __elems_before = __pos - __old_start;
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pointer __new_start(this->_M_allocate(__len));
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pointer __new_finish(__new_start);
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__try
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@ -584,15 +590,13 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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__new_finish
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= std::__uninitialized_move_if_noexcept_a
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(this->_M_impl._M_start, __position.base(),
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__new_start, _M_get_Tp_allocator());
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(__old_start, __pos, __new_start, _M_get_Tp_allocator());
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__new_finish += __n;
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__new_finish
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= std::__uninitialized_move_if_noexcept_a
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(__position.base(), this->_M_impl._M_finish,
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__new_finish, _M_get_Tp_allocator());
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(__pos, __old_finish, __new_finish, _M_get_Tp_allocator());
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}
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__catch(...)
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{
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@ -606,12 +610,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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_M_deallocate(__new_start, __len);
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__throw_exception_again;
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}
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std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
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_M_get_Tp_allocator());
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std::_Destroy(__old_start, __old_finish, _M_get_Tp_allocator());
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_GLIBCXX_ASAN_ANNOTATE_REINIT;
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_M_deallocate(this->_M_impl._M_start,
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this->_M_impl._M_end_of_storage
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- this->_M_impl._M_start);
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_M_deallocate(__old_start,
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this->_M_impl._M_end_of_storage - __old_start);
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this->_M_impl._M_start = __new_start;
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this->_M_impl._M_finish = __new_finish;
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this->_M_impl._M_end_of_storage = __new_start + __len;
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@ -645,6 +647,11 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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}
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else
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{
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// Make local copies of these members because the compiler thinks
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// the allocator can alter them if 'this' is globally reachable.
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pointer __old_start = this->_M_impl._M_start;
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pointer __old_finish = this->_M_impl._M_finish;
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const size_type __len =
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_M_check_len(__n, "vector::_M_default_append");
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pointer __new_start(this->_M_allocate(__len));
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@ -660,7 +667,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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_M_deallocate(__new_start, __len);
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__throw_exception_again;
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}
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_S_relocate(this->_M_impl._M_start, this->_M_impl._M_finish,
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_S_relocate(__old_start, __old_finish,
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__new_start, _M_get_Tp_allocator());
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}
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else
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@ -672,7 +679,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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__n, _M_get_Tp_allocator());
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__destroy_from = __new_start + __size;
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std::__uninitialized_move_if_noexcept_a(
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this->_M_impl._M_start, this->_M_impl._M_finish,
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__old_start, __old_finish,
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__new_start, _M_get_Tp_allocator());
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}
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__catch(...)
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@ -683,13 +690,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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_M_deallocate(__new_start, __len);
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__throw_exception_again;
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}
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std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
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std::_Destroy(__old_start, __old_finish,
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_M_get_Tp_allocator());
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}
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_GLIBCXX_ASAN_ANNOTATE_REINIT;
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_M_deallocate(this->_M_impl._M_start,
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this->_M_impl._M_end_of_storage
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- this->_M_impl._M_start);
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_M_deallocate(__old_start,
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this->_M_impl._M_end_of_storage - __old_start);
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this->_M_impl._M_start = __new_start;
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this->_M_impl._M_finish = __new_start + __size + __n;
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this->_M_impl._M_end_of_storage = __new_start + __len;
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@ -782,6 +788,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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}
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else
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{
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// Make local copies of these members because the compiler
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// thinks the allocator can alter them if 'this' is globally
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// reachable.
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pointer __old_start = this->_M_impl._M_start;
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pointer __old_finish = this->_M_impl._M_finish;
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const size_type __len =
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_M_check_len(__n, "vector::_M_range_insert");
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pointer __new_start(this->_M_allocate(__len));
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@ -790,7 +802,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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{
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__new_finish
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= std::__uninitialized_move_if_noexcept_a
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(this->_M_impl._M_start, __position.base(),
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(__old_start, __position.base(),
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__new_start, _M_get_Tp_allocator());
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__new_finish
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= std::__uninitialized_copy_a(__first, __last,
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@ -798,7 +810,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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_M_get_Tp_allocator());
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__new_finish
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= std::__uninitialized_move_if_noexcept_a
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(__position.base(), this->_M_impl._M_finish,
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(__position.base(), __old_finish,
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__new_finish, _M_get_Tp_allocator());
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}
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__catch(...)
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@ -808,12 +820,11 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
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_M_deallocate(__new_start, __len);
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__throw_exception_again;
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}
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std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
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std::_Destroy(__old_start, __old_finish,
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_M_get_Tp_allocator());
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_GLIBCXX_ASAN_ANNOTATE_REINIT;
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_M_deallocate(this->_M_impl._M_start,
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this->_M_impl._M_end_of_storage
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- this->_M_impl._M_start);
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_M_deallocate(__old_start,
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this->_M_impl._M_end_of_storage - __old_start);
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this->_M_impl._M_start = __new_start;
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this->_M_impl._M_finish = __new_finish;
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this->_M_impl._M_end_of_storage = __new_start + __len;
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