Intermittent access violation with extension of parameterised type

[IanH]

The attached example fails intermittently (it may need to be run several times to see the failure) when compiled with 17.0 update one.  I think the code is legit.

MODULE FortranLib
  IMPLICIT NONE
  
  PRIVATE
  
  !--------------------------------------------------------------------
  
  TYPE, ABSTRACT, PUBLIC :: Parent(param)
    INTEGER, LEN :: param
  END TYPE Parent
  
  !--------------------------------------------------------------------
  
  PUBLIC :: CreateExtension
  
  TYPE, EXTENDS(Parent) :: extension
    CHARACTER(:), ALLOCATABLE :: name
  END TYPE extension
CONTAINS
  SUBROUTINE CreateExtension(name, object)
    CHARACTER(*), INTENT(IN) :: name
    CLASS(Parent(:)), INTENT(OUT), ALLOCATABLE :: object
    
    TYPE(extension(:)), ALLOCATABLE :: tmp
    
    ALLOCATE(extension(3) :: tmp)
    tmp%name = name                   !<<<<<
    CALL MOVE_ALLOC(tmp, object)
  END SUBROUTINE CreateExtension
END MODULE FortranLib


PROGRAM FortranExample
  USE FortranLib
  IMPLICIT NONE
  
  CLASS(Parent(:)), ALLOCATABLE :: x
  
  CALL CreateExtension('Fred', x)
END PROGRAM FortranExample

The symptoms of the failure, when it fails, varies - sometimes it is an access violation, sometimes a complaint about an allocatable that cannot be deallocated, sometimes the "this program stopped working" dialog box, sometimes a refusal to write any further code until someone restocks the coffee.

>ifort /check:all /warn:all /standard-semantics /Od /debug /traceback "2016-11-22 boom.f90" && "2016-11-22 boom.exe"
Intel(R) Visual Fortran Intel(R) 64 Compiler for applications running on Intel(R) 64, Version 17.0 Build 20161005
Copyright (C) 1985-2016 Intel Corporation.  All rights reserved.

Microsoft (R) Incremental Linker Version 14.00.24215.1
Copyright (C) Microsoft Corporation.  All rights reserved.

"-out:2016-11-22 boom.exe"
-debug
"-pdb:2016-11-22 boom.pdb"
-subsystem:console
-incremental:no
"2016-11-22 boom.obj"
forrtl: severe (157): Program Exception - access violation
Image              PC                Routine            Line        Source
2016-11-22 boom.e  00007FF70FEE2F6D  Unknown               Unknown  Unknown
2016-11-22 boom.e  00007FF70FE43625  Unknown               Unknown  Unknown
2016-11-22 boom.e  00007FF70FE414FC  FORTRANLIB_mp_CRE          27  2016-11-22 boom.f90
2016-11-22 boom.e  00007FF70FE418D7  MAIN__                     39  2016-11-22 boom.f90
2016-11-22 boom.e  00007FF70FED73DE  Unknown               Unknown  Unknown
2016-11-22 boom.e  00007FF70FED7E4D  Unknown               Unknown  Unknown
KERNEL32.DLL       00007FFD74C18364  Unknown               Unknown  Unknown
ntdll.dll          00007FFD77705E91  Unknown               Unknown  Unknown

[Steven_L_Intel1]

Thanks - we'll check it out.

[Steven_L_Intel1]

Escalated as issue DPD200416168. I could reproduce it in Visual Studio, even did an Inspector XE run on it, and then it started working fine. I can reproduce from the command line with reasonable consistency. My guess is that a bad address is being passed to the memory copy routine.