https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108850
Bug ID: 108850
Summary: SELECT CASE within BLOCK construct in one subroutine
prevents compilation of another subroutine named
"SELECT"
Product: gcc
Version: 10.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: johnww at tds dot net
Target Milestone: ---
Created attachment 54489
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54489&action=edit
Output from "gfortran -v -save-temps -c select_within_block.f90"
Verbose compilation output is in the attachment.
With gfortran 10.2.1 (as I found earlier with 4.9.2) the following code fails
to compile:
module m
implicit none
private
public :: a, select
contains
subroutine a(x)
integer, intent(in) :: x
! cut down from named block construct with exits
block
select case (x)
case (1)
! ...
case (2)
! ...
end select
end block
end subroutine a
! compiles successfully if name is not 'select'
subroutine select
end subroutine select
end module m
Error messages are:
select_within_block.f90:23:20:
23 | subroutine select
| 1
Error: VARIABLE attribute of ‘select’ conflicts with PROCEDURE attribute at (1)
select_within_block.f90:24:6:
24 | end subroutine select
| 1
Error: Expecting END MODULE statement at (1)
select_within_block.f90:5:22:
5 | public :: a, select
| 1
Error: Symbol ‘select’ at (1) has no IMPLICIT type
The second and third errors are clearly consequences of the first error, which
makes no sense to me.
There are easy workarounds: rename subroutine select; replace the block
construct with a do construct containing a final unconditional exit.
While this failed compilation involved a very specific choice of procedure
name, I suspect it is merely one case of a wider problem.
While I first encountered this with version 4.9.2, I waited until I could check
(after an upgrade) with a recent version of the compiler before I spent the
time to cut down a large module to a minimal example that exhibited the
problem.
There was no preprocessed file (*.i*) produced from the failed compilation.
