Fortran type bound function returning short integer fails

Accelerated Computing HPC Compilers nvc, nvc++ and nvfortran
1

Hello,

we are trying to compile some Fortran libraries and we encounter some errors. We extracted the following minimal reproducing example which fails using nvfortran 20.7.

program test
type :: a_object
contains
procedure :: to_integer_I2P
endtype a_object

integer, parameter :: I2P=selected_int_kind(4)
type(a_object) :: object

print*, object%to_integer_I2P()
contains
function to_integer_I2P(self) result(n) ! it does not work
class(a_object) :: self
integer(I2P) :: n
endfunction to_integer_I2P
endprogram test

Thanks
Francesco

2

The code doesn’t seem valid (at least it errors with ifort and gfortran). Is the issue that nvfortran isn’t catching the errors as well? I can submit a problem report, but given this is from a larger, presumably correct, code, I want to make sure our engineers are fixing the correct issue.

    % ifort --version
    ifort (IFORT) 19.1.1.217 20200306
    Copyright (C) 1985-2020 Intel Corporation.  All rights reserved.

     % ifort test.f90
    test.f90(4): error #8258: The procedure name in a type-bound procedure declaration should be the name of an accessible module procedure or an external procedure that has an explicit interface.   [TO_INTEGER_I2P]
    procedure :: to_integer_I2P
    -------------^
    test.f90(10): error #8607: The procedure interface for the type bound procedure is not yet available.   [TO_INTEGER_I2P]
    print*, object%to_integer_I2P()
    ---------------^
    test.f90(10): error #8497: Illegal use of a procedure name in an expression, possibly a function call missing parenthesis.   [TO_INTEGER_I2P]
    print*, object%to_integer_I2P()
    ---------------^
    test.f90(12): warning #6178: The return value of this FUNCTION has not been defined.   [N]
    function to_integer_I2P(self) result(n) ! it does not work
    -------------------------------------^
    compilation aborted for test.f90 (code 1)
    % gfortran --version
    GNU Fortran (GCC) 9.2.0
    Copyright (C) 2019 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 test.f90
    test.f90:4:9:

        4 | procedure :: to_integer_I2P
          |         1
    Error: ‘to_integer_i2p’ must be a module procedure or an external procedure with an explicit interface at (1)
    test.f90:10:7:

   10 | print*, object%to_integer_I2P()
  |       1
Error: ‘to_integer_i2p’ at (1) should be a FUNCTION
3

Sorry, we reduced the code too much. However, including explicit interfaces using a module:

module test
type :: a_object
contains
procedure :: to_integer_I2P
endtype a_object

! integer, parameter :: I2P=selected_int_kind(9) ! this works
integer, parameter :: I2P=selected_int_kind(4) ! this does not work

contains
function to_integer_I2P(self) result(n)
class(a_object) :: self
integer(I2P) :: n
endfunction to_integer_I2P
endmodule test

we still have the following error using nvfortran x86 compiler (ppc64 nvfortran compiler works, gfortran works):

/opt/nvidia/hpc_sdk/Linux_x86_64/20.7/compilers/share/llvm/bin/llc: error: /opt/nvidia/hpc_sdk/Linux_x86_64/20.7/compilers/share/llvm/bin/llc: /tmp/nvfortranCeXdu9xI6Tl-.ll:8:67: error: invalid forward reference to function ‘test_to_integer_i2p_’ with wrong type: expected ‘i32 (i64*, i64*)’ but was 'i32 ()’
@test$a_object$$td$vft = global [1 x i8*] [i8* bitcast(i32 ()* @test_to_integer_i2p_ to i8*)]

Francesco

4

Thanks Francesco, we appreciate that. I added a new problem report (TPR#29177) for the LLVM code generation issue. I also went ahead and added TPR#29118 to see if we can catch the errors in the earlier code as well.

-Mat

5

This issue was fixed in our 20.11 release.

6

TPR#29118 was fixed in 22.3 and the compiler now catches the error in the initial incorrect example:

% nvfortran test.f90 -V22.3
NVFORTRAN-F-1249-Type-bound procedure to_integer_i2p must be a module procedure or external procedure with an explicit interface. (test.f90: 10)
NVFORTRAN/x86-64 Linux 22.3-0: compilation aborted