https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112766
Bug ID: 112766
Summary: [14 regression] spurious -Wmaybe-uninitialized with
array new
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: s...@li-snyder.org
Target Milestone: ---
hi -
With a recent checkout of gcc14 (20231129), on a x86_64-pc-linux-gnu host,
the following source gives a bogus -Wmaybe-uninitialized warning
with -Wall:
--------------------------------------------------------------
void* operator new[](unsigned long, void* __p) ;
class Result
{
public:
Result();
~Result();
};
void *foo(long nElements, void *p) {
return p ? new((int*)p) Result[nElements] : new Result[nElements];
}
--------------------------------------------------------------
$ g++ -c -O1 -Wall x.cc
x.cc: In function ‘void* foo(long int, void*)’:
x.cc:11:67: warning: ‘nElements.6’ may be used uninitialized
[-Wmaybe-uninitialized]
11 | return p ? new((int*)p) Result[nElements] : new Result[nElements];
| ^
x.cc:11:58: note: ‘nElements.6’ was declared here
11 | return p ? new((int*)p) Result[nElements] : new Result[nElements];
| ^~~~~~~~~
We get the same warning with -O2 and -O3, but not -O0.
This warning does not occur with gcc 13.2.1 20230728.
