[flang-commits] [flang] [flang] Fix lowering of unused dummy procedure pointers (PR #155649)

[Daniel Chen via flang-commits]

DanielCChen wrote:

```
  MODULE M0

    TYPE :: Base
      CHARACTER(3) :: C
    END TYPE

  END MODULE

  MODULE M
  USE M0

    TYPE, EXTENDS(Base)  :: DT
      PROCEDURE(IFun), NOPASS, POINTER :: ProcPtr
    CONTAINS
      PROCEDURE, NOPASS :: Proc=>ModFun
    END TYPE

    CONTAINS

    FUNCTION ModFun(Arg)
    TYPE(DT), INTENT(IN) :: Arg
    TYPE(DT)             ::  ModFun
      ModFun = Arg
    END FUNCTION

    FUNCTION IFun(Arg)
    TYPE(DT), INTENT(IN) :: Arg
    TYPE(DT)             :: IFun
      IFun = Arg
    END FUNCTION

  END MODULE

  FUNCTION ExtFun(Arg)
  USE M
  TYPE(DT), INTENT(IN) :: Arg
  TYPE(DT)             ::  ExtFun
    ExtFun = Arg
  END FUNCTION

  PROGRAM Arg5
  USE M
  IMPLICIT NONE
  PROCEDURE(IFun) :: ExtFun
  PROCEDURE(IFun), POINTER :: ProcPtr

  INTERFACE
    FUNCTION IFun1(Arg)
      IMPORT DT
      TYPE(DT), INTENT(IN) :: Arg
      TYPE(DT)             :: IFun1
    END FUNCTION
  END INTERFACE

  ProcPtr => ExtFun
  CALL IntSub( ProcPtr, ProcPtr)

  CONTAINS
  
    SUBROUTINE IntSub(ProcPtr0, ProcPtr1)
  IMPLICIT TYPE(DT)(P)

  PROCEDURE(IFun1),      POINTER :: ProcPtr0
  PROCEDURE(TYPE(DT)),   POINTER :: ProcPtr1
  TYPE(DT)                       :: V

  V = ProcPtr0(DT("321", ProcPtr0))
  IF (V%C .NE. "321") STOP 21
  IF ( .NOT. ASSOCIATED(V%ProcPtr, ProcPtr) ) STOP 22

  V = ProcPtr1(DT("121", ExtFun))
  IF (V%C .NE. "121") STOP 31
  IF ( .NOT. ASSOCIATED(V%ProcPtr, ExtFun) ) STOP 32

  END SUBROUTINE

  END
  ```

https://github.com/llvm/llvm-project/pull/155649