[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 Vivek Rao changed: What|Removed |Added CC||vivekrao4 at yahoo dot com --- Comment #13 from Vivek Rao --- Many warnings that I think are spurious for the code program main implicit none character (len=:), allocatable :: words(:) words = ["dog","cat"] print*,words end program main compiled with gfortran -Wall xalloc_char.f90 using GNU Fortran (GCC) 12.0.0 20211024 (experimental) from equation.com on Windows gives xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ Warning: '.words' is used uninitialized [-Wuninitialized] xalloc_char.f90:1:12: 1 | program main |^ note: '.words' was declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.offset' is used uninitialized [-Wuninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.dim[0].lbound' is used uninitialized [-Wuninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.dim[0].ubound' is used uninitialized [-Wuninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.dim[0].lbound' may be used uninitialized [-Wmaybe-uninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.dim[0].ubound' may be used uninitialized [-Wmaybe-uninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.dim[0].ubound' may be used uninitialized [-Wmaybe-uninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here xalloc_char.f90:4:21: 4 | words = ["dog","cat"] | ^ Warning: 'words.dim[0].lbound' may be used uninitialized [-Wmaybe-uninitialized] xalloc_char.f90:3:42: 3 | character (len=:), allocatable :: words(:) | ^ note: 'words' declared here
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670
--- Comment #12 from Tobias Burnus ---
character(len=:), allocatable :: aa(:)
character(len=:), pointer :: pp(:)
allocate(character(len=5) :: aa(5), pp(5))
end
gives with gfortran -Wall
1 | character(len=:), allocatable :: aa(:)
| ^
Warning: ‘.aa’ is used uninitialized [-Wuninitialized]
afoo.f90:2:34:
2 | character(len=:), pointer :: pp(:)
| ^
Warning: ‘.pp’ is used uninitialized [-Wuninitialized]
The reason is how dtype is initialized:
D.3965 = (bitsizetype) (sizetype) NON_LVALUE_EXPR <.aa> * 8;
D.3966 = (sizetype) NON_LVALUE_EXPR <.aa>;
aa.data = 0B;
aa.dtype = {.elem_len=(unsigned long) .aa, .rank=1, .type=6};
Later with the alloc, it is correctly set, i.e. it is only an issue for the
initial deallocate state; during allocate:
.aa = 5;
aa.dtype = {.elem_len=(unsigned long) .aa, .rank=1, .type=6};
=> Solution: Don't set .elem_len if the typespec is expr->ts.deferred)
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 Seth Johnson changed: What|Removed |Added CC||johnsonsr at ornl dot gov --- Comment #11 from Seth Johnson --- I confirm that with both 10.2 and 8.3, the example code prints the erroneous warning with `-O0` and works as expected (no warning) with `-O1` and higher. ``` $FC "-Wall" -O1 -c ./ftest.f90 ``` ```fortran subroutine do_stuff() character(len=*), parameter :: src = "nope" character(len=:), allocatable :: dst dst = src write(*,*) dst end subroutine ```
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 Martin Sebor changed: What|Removed |Added Known to fail||10.2.0, 11.0, 4.8.4, 4.9.4, ||5.5.0, 6.4.0, 7.2.0, 8.3.0, ||9.1.0 Last reconfirmed|2014-03-22 00:00:00 |2021-3-26 CC||msebor at gcc dot gnu.org --- Comment #10 from Martin Sebor --- Reconfirming with GCC 11.
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 --- Comment #9 from Dominique d'Humieres --- The dump-tree-original shows ... if (name_format != 0B) goto L.1; name_format = (character(kind=1)[1:.name_format] *) __builtin_malloc (1); goto L.2; L.1:; if (.name_format == 0) goto L.2; name_format = (character(kind=1)[1:.name_format] *) __builtin_realloc ((void *) name_format, 1); L.2:; .name_format = 0; ...
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 Dominique d'Humieres changed: What|Removed |Added CC||adam at aphirst dot karoo.co.uk --- Comment #8 from Dominique d'Humieres --- *** Bug 88455 has been marked as a duplicate of this bug. ***
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 Dominique d'Humieres changed: What|Removed |Added CC||fmartinez at gmv dot com --- Comment #7 from Dominique d'Humieres --- *** Bug 60122 has been marked as a duplicate of this bug. ***
[Bug fortran/56670] Allocatable-length character var causes bogus warning with -Wuninitialized
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56670 janus at gcc dot gnu.org changed: What|Removed |Added Summary|Allocatable-length |Allocatable-length |character var causes bogus |character var causes bogus |warning with -Wall |warning with ||-Wuninitialized --- Comment #6 from janus at gcc dot gnu.org --- (In reply to janus from comment #5) > Related test case: This is probably a separate problem, since it is also connected to a wrong-code bug, see PR 86372.
