https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123903
anlauf at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |wrong-code
Status|UNCONFIRMED |NEW
Last reconfirmed| |2026-01-31
Ever confirmed|0 |1
CC| |anlauf at gcc dot gnu.org
Component|libfortran |fortran
--- Comment #1 from anlauf at gcc dot gnu.org ---
Actually it is wrong code.
Tree-dump:
void MAIN__ ()
{
integer(kind=8) .s;
character(kind=1)[1:.s] * s;
...
D.4689 = (void * restrict) __builtin_malloc (MAX_EXPR <(unsigned
long) (.s + 1), 1>);
pstr.0 = (character(kind=1)[1:] *) D.4689;
_gfortran_concat_string (.s + 1, pstr.0, .s, s, 1, &"a"[1]{lb: 1 sz:
1});
Note that .s is initialized to 0, but s is never set.
% gfc-16 -fdump-tree-original pr123903.f90 -g -fsanitize=address && ./a.out
Program received signal SIGSEGV: Segmentation fault - invalid memory reference.
Backtrace for this error:
#0 0x7f8db535f08f in ???
#1 0x7f8db54851dd in ???
#2 0x401356 in MAIN__
at /home/anlauf/gcc-bugs/pr123903.f90:2
#3 0x40176e in main
at /home/anlauf/gcc-bugs/pr123903.f90:4
Segmentation fault
We should be able to make one of the -fcheck=... options handle this.
