https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108872
Bug ID: 108872
Summary: ICE in main_block_label, missing label when assigning
a derived type whose component has a defined
assignment
Product: gcc
Version: 12.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: trnka at scm dot com
Target Milestone: ---
gfortran (tested versions 9 through 12.2.1 20221121) crashes when compiling the
following testcase because the "bb" pointer is null in main_block_label()
called from cleanup_dead_labels() in tree-cfg.c:
module TestModule
implicit none
private
type :: A
integer :: i = 0
contains
procedure :: NewCopyOther
generic :: assignment(=) => NewCopyOther
end type
type :: B
type(A) :: aa
end type
type :: C
type(B) :: x
contains
procedure :: Run
end type
contains
subroutine NewCopyOther(self, other)
class(A), intent(out) :: self
class(A), intent(in) :: other
self%i = other%i
end subroutine
subroutine Run(self)
class(C), intent(inout) :: self
type(B) :: y
goto 2
2 y = self%x
end subroutine
end module
Apparently, the Fortran frontend never emits the "2" label as long as it's
placed on a line containing an assignment of a derived type (B) which has a
component with a defined assignment operator (A). The "original" dump for run()
looks like the following:
__attribute__((fn spec (". w ")))
void run (struct __class_testmodule_C_t & restrict self)
{
struct b y;
{
struct b b.2;
b.2.aa.i = 0;
y = b.2;
}
goto __label_000002;
y = self->_data->x;
{
struct __class_testmodule_A_t class.0;
struct __class_testmodule_A_t class.1;
class.0._vptr = (struct __vtype_testmodule_A * {ref-all})
&__vtab_testmodule_A;
class.0._data = &y.aa;
class.1._vptr = (struct __vtype_testmodule_A * {ref-all})
&__vtab_testmodule_A;
class.1._data = &self->_data->x.aa;
newcopyother (&class.0, &class.1);
}
}
__label_000002 is thus used in a goto even though it's nowhere to be seen.
I guess bug 95613 might be related but probably not a duplicate as that one has
nothing to do with defined assignments.
