https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64118
Bug ID: 64118
Summary: Strange warning about unused function/subroutine
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: angelo.graziosi at alice dot it
Created attachment 34144
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34144&action=edit
Tar archive with source code
With the attached tests I get the following warning:
$ gfortran -Wall test_unused_func.f90 -o test_unused_func.out
test_unused_func.f90:54:0: warning: ‘f’ defined but not used
[-Wunused-function]
real(dp) function f(x) result(y)
^
$ gfortran -Wall test_unused_sub.f90 -o test_unused_sub.out
test_unused_sub.f90:44:0: warning: ‘sub3’ defined but not used
[-Wunused-function]
subroutine sub3()
^
test_unused_sub.f90:40:0: warning: ‘sub2’ defined but not used
[-Wunused-function]
subroutine sub2()
^
test_unused_sub.f90:36:0: warning: ‘sub1’ defined but not used
[-Wunused-function]
subroutine sub1()
^
which I find a bit "strange": after all, the function f() in the first test,
for example, is used because it is passed to the call of simpson().. and indeed
$ ./test_unused_func.out
1.4250604553524227
1.9202581413298656
confirming it is _used_!
I found this using gfortran from GCC: 4.8.2 (MSYS2 64), 4.8.3 (OSX+MacPorts 64,
Cygwin64), 4.9.1 (MSYS2+MinGW64), but maybe also recent versions of gfortran
are affected.
The tests are archived in the attached tar-ball.
See also the discussion on gfortran mailing list:
https://gcc.gnu.org/ml/fortran/2014-07/msg00168.html
https://gcc.gnu.org/ml/fortran/2014-11/msg00143.html
Ciao,
Angelo.
