I am experiencing compilation errors in my code due to a conflict between overloaded assignments and structure constructors. I can easily solve the problem, but I'd still like to know if I'm abusing the Fortran 2003 language or not in the following toy code:
MODULE matrices IMPLICIT NONE PRIVATE PUBLIC :: oldmatrix TYPE :: oldmatrix COMPLEX :: a(2,2) CONTAINS PRIVATE PROCEDURE, PASS :: eq_mat GENERIC, PUBLIC :: ASSIGNMENT(=) => eq_mat END TYPE oldmatrix INTERFACE oldmatrix MODULE PROCEDURE ctor_mat END INTERFACE oldmatrix CONTAINS PURE ELEMENTAL FUNCTION ctor_mat RESULT(u) REAL, INTENT(in) :: r TYPE(oldmatrix) :: u INTEGER :: i u%a = CMPLX(0.,0.) DO i=1,2 u%a(i,i) = r END DO END FUNCTION ctor_mat PURE ELEMENTAL SUBROUTINE eq_mat(v, u) CLASS(oldmatrix), INTENT(out) :: v TYPE(oldmatrix), INTENT(in) :: u v%a = u%a END SUBROUTINE eq_mat END MODULE matrices PROGRAM test USE matrices IMPLICIT NONE TYPE, EXTENDS(oldmatrix) :: newmatrix END TYPE newmatrix TYPE(oldmatrix) :: x TYPE(newmatrix) :: y COMPLEX, PARAMETER :: unit(2,2) = [[1.,0.],[0.,1.]] #if _OPTION == 1 y = oldmatrix(unit) #elif _OPTION == 2 x = oldmatrix(unit) y = x #elif _OPTION == 3 y = oldmatrix(1.) #endif PRINT *, y END PROGRAM test
The module provides the derived type "oldmatrix", a type-bound assignment (that allows me to assign objects of parent type "oldmatrix" to an object of an extended/child type), and an user-defined structure constructor. In the program I extend the parent type "oldmatrix" trivially to the child type "newmatrix". Then, I try to assign an "oldmatrix" object to the "newmatrix" object "y": In _OPTION=1, I use the default structure constructor of "oldmatrix" for this purpose; in _OPTION=2, I use an auxiliary "oldmatrix" object "x" before assigning it to "y"; in _OPTION=3, I use the user-defined structure constructor.
I am using the latest ifort to compile the code. If I compile it with
ifort test.f90 -c -fpp -D_OPTION=1
then I get a catastrophic error:
0_1670test.f90(56): catastrophic error: **Internal compiler error: internal abort** Please report this error along with the circumstances in which it occurred in a Software Problem Report. Note: File and line given may not be explicit cause of this error.compilation aborted for test.f90 (code 1)
If I compile it with -D_OPTION=2 or -D_OPTION=3, then it compiles, builds, and runs successfully.
It looks to me as if the default constructor for "oldmatrix" and the type-bound overloaded assignment are not working in harmony with each other, because there are no problems with the user-defined structure contructor, nor if I use an auxiliary "oldmatrix" object to do the assignment step-by-step.
It compiles and builds successfully with both PGI and GNU compilers. Is this an issue of the Intel compiler, or am I abusing the Fortran 2003 language by trying to use the default structure constructor and an overloaded assignment in the same statement?