https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111261
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |hubicka at gcc dot gnu.org
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
In fact with trunk we diagnose this properly with -std=c++17 but not
-std=c++20.
With -std=c++20 we see
<bb 2> [local count: 1073741824]:
_35 = operator new (21);
__builtin_memcpy (_35, "A rather long string", 20);
MEM[(char_type &)_35 + 20] = 0;
operator delete (_35, 21);
s ={v} {CLOBBER};
s ={v} {CLOBBER(eol)};
return 0;
at the point we would be supposed to diagnose the init but you can see
that 's' was elided.
One issue is probably that we elide the standalone S::S() during IPA
(because we inline it) and thus fail to run the late diagnostic passes
on its optimized body:
void S::S (struct S * const this)
{
struct allocator D.46788;
struct string * _1;
struct string * _2;
long unsigned int _8;
<bb 2> [local count: 1073741824]:
_8 = MEM[(const struct basic_string *)this_3(D) + 8B]._M_string_length;
*this_3(D).len = _8;
_1 = &this_3(D)->s;
std::__cxx11::basic_string<char>::basic_string<> (_1, "A rather long string",
&D.46788);
D.46788 ={v} {CLOBBER(eol)};
return;
of course we lack a start-of-live CLOBBER of *this here (I think I've seen
this before), so we'd fail to diagnose this body as well.
