https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106035
Jorge D'Elia <jde...@santafe-conicet.gov.ar> changed:
What |Removed |Added
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CC| |jde...@santafe-conicet.gov.
| |ar
--- Comment #5 from Jorge D'Elia <jde...@santafe-conicet.gov.ar> ---
Hi,
The access restriction is a reason of the use IMPORT statements in the
projects, since it is a very convenient and nifty way to detect any name
collision between local entities and host-associated entities, and well as, in
BLOCK statements, for the same purpose. However, with the test:
$ cat import1.f90
module m_modulo
implicit none (type, external)
contains
subroutine ss (ii)
import, all
implicit none (type, external)
integer, intent (in) :: ii
associate (i_loc => ii)
end associate
end subroutine ss
end module m_modulo
compiled with, (i)
$ gfortran --version
GNU Fortran (GCC) 12.3.1 20230508 (Red Hat 12.3.1-1)
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ gfortran -march=native -mtune=native -m64 -fall-intrinsics -fcheck=all
-fimplicit-none -fmax-errors=4 -fno-finite-math-only -fPIC -pthread -std=f2018
-Wall -Waliasing -Warray-temporaries -Wcharacter-truncation -Werror -Wextra
-Wimplicit-interface -Wimplicit-procedure -Wintrinsic-shadow -Wline-truncation
-Wrealloc-lhs-all -Wsurprising -Wtabs -Wunused-parameter -flto -O2 -o
import1.exe import1.f90
import1.f90:5:11:
5 | import, all
| 1
Error: IMPORT statement at (1) only permitted in an INTERFACE body
f951: all warnings being treated as errors
and next compiled with (ii):
$ nagfor ../import1.f90 -O3
rm: cannot remove '*.original': No such file or directory
NAG Fortran Compiler Release 7.1(Hanzomon) Build 7115
Error: ../import1.f90, line 2: Syntax error
detected at NONE@(
Error: ../import1.f90, line 5: The IMPORT statement is only allowed in an
INTERFACE body
detected at IMPORT@,
Error: ../import1.f90, line 5: Syntax error
detected at IMPORT@,
Error: ../import1.f90, line 6: Syntax error
detected at NONE@(
[NAG Fortran Compiler pass 1 error termination, 4 errors]
Thus, the errors generated by gfortran and nagfor are consistent with the F2003
constraint: C1210 (R1209) "The IMPORT statement is allowed only in an
interface-body".
However, the use of IMPORT in the previus test is new in F2018, which neither
gfortran nor NAG Fortran support, that is: "The IMPORT statement can appear in
a contained subprogram or BLOCK construct, and can restrict access via host
association; diagnosis of violation of the IMPORT restrictions is required".
Thus, this example should be valid F2018 but not F2008 or earlier.
For instance, one can have a unit testing framework that relies extensively on
BLOCK constructs, and having the guarantee that any potential conflict (between
a local block entity and an entity of the host procedure) will be flagged by
the compiler (when using an IMPORT statement in each block construct) sould be
a godsend.
