Add support for GoTo Implementation in submodules

[gha3mi]

fortls can detect the interface in a module, but not its implementation in a submodule, see this example.

MODULE MOD

IMPLICIT NONE

!==============================================================================
TYPE :: TYP
    REAL(KIND=8) :: value
CONTAINS
    PROCEDURE :: PRC1 => PRC_PRC1
END TYPE TYP
!==============================================================================


!==============================================================================
INTERFACE
    MODULE  SUBROUTINE PRC_PRC1(this)

        IMPLICIT NONE

        CLASS(TYP), INTENT(INOUT) :: this

    END SUBROUTINE PRC_PRC1
END INTERFACE
!==============================================================================

END MODULE MOD

SUBMODULE(MOD) SMOD

IMPLICIT NONE

CONTAINS

!==============================================================================
MODULE SUBROUTINE PRC_PRC1(this)

    IMPLICIT NONE

    CLASS(TYP), INTENT(INOUT) :: this

    this%value = 0

END SUBROUTINE PRC_PRC1
!==============================================================================

END SUBMODULE SMOD

[gnikit]

Could you please elaborate as to what fortls is currently doing and what the expected behaviour should be?

[gha3mi]

In this example, go to definition (vscode: F12) for procedure PRC_PRC1 can find the module subroutine PRC_PRC1 in the interface, but not the implementation of module subroutine PRC_PRC1 in submodule SMOD, also fortls does not give any information about the implementation of the procedure PRC_PRC1 in the submodule SMOD.

[gnikit]

I see what you mean. I think both issues that you are mentioning are effectively the same. GoTo Implementation does not detect the implementation for submodules.

I will look into it, thanks!

[gnikit]

This has turned out to be a bit tricker that what I originally thought. Since the object associated with the interface does not hold a reference to the object with the implementation. I will have to redesign some bits but I think it is doable.

[gha3mi]

Hi @gnikit, I would like to ask you if there is a plan for this issue?

[gnikit]

I started to work on it, but then I encountered a series of other bugs along the way with the parser and constants so I got side-tracked. Right now I am slightly busy with PhD work, so it might be a while until I get to this.

I am making a project with the most critical bugs to fix, I will try to have a look at this end of day today, but people are also invited to try and help.

[gha3mi]

Thank you for your reply, I am also very busy at the moment. I will try to contribute when I find some free time.