commit cca06f0d6d76b08ed4ddb7667eda93e2e9f2589e
author Jonathan Wakely <jwakely@redhat.com> Tue Nov 29 15:50:06 2022 +0000
committer Jonathan Wakely <jwakely@redhat.com> Tue Nov 29 17:01:32 2022 +0000
tree 3e22e09174f7995e1cb27b3e830aca9e419d170a
parent 81cf0354d5f81f2c7600a3bc7ae4600757286995

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.