https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71156
Bug ID: 71156
Summary: PURE interface/definition inconsistency: accepts
invalid, rejects valid
Product: gcc
Version: 6.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: damian at sourceryinstitute dot org
Target Milestone: ---
As shown below, gfortran 6.1.0 rejects the application of the PURE attribute
consistently in a procedure interface body and the corresponding procedure
definition.
Conversely, gfortran accepts the inconsistent approach (not shown) of using
PURE in the interface body but omitting PURE from the procedure definition. By
contrast, the Cray and Intel compilers behave opposite to gfortran: Intel and
Cray accept the consistent syntax below and reject the inconsistent syntax in
which PURE appears only in the interface body or only in the definition. If
Intel and Cray are correct, then gfortran is accepting invalid code and
rejecting the complementary valid code and it would be great if a fix could be
applied to the 6 and 7 branches.
$ cat consistency.f90
module my_interface
implicit none
interface
pure module subroutine f
end subroutine
end interface
end module
submodule(my_interface) my_implementation
implicit none
contains
pure module subroutine f
end subroutine
end submodule
$ gfortran -c consistency.f90
consistency.f90:12:28:
pure module subroutine f
1
Error: Duplicate PURE attribute specified at (1)
$ gfortran --version
GNU Fortran (MacPorts gcc6 6.1.0_0) 6.1.0
