https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106434
--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Slightly simpler, with correct assertion now:
--- a/libstdc++-v3/include/bits/vector.tcc
+++ b/libstdc++-v3/include/bits/vector.tcc
@@ -139,6 +139,11 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
{
const size_type __n = __position - begin();
if (this->_M_impl._M_finish != this->_M_impl._M_end_of_storage)
+ {
+ __glibcxx_assert(__position != const_iterator());
+ if (__position == const_iterator())
+ __builtin_unreachable(); // PR 106434
+
if (__position == end())
{
_GLIBCXX_ASAN_ANNOTATE_GROW(1);
@@ -159,6 +164,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
_M_insert_aux(__position, __x);
#endif
}
+ }
else
#if __cplusplus >= 201103L
_M_realloc_insert(begin() + (__position - cbegin()), __x);
The __builtin_unreachable would be unnecessary if __glibcxx_assert expanded to
that when assertions are disabled (so the macro expands to either an assertion,
or a hint that the condition is always true). I think I tried that and it
caused problems though.
