[flang] Add semantics test for coshape() function

[ktras]

Test looks great, but I suggest adding to the error section by adding an attempt to assign the result of a correct coshape() call to a variable of type character, as there is no automatic conversion upon assignment between character and integer (which is of course the correct type of the returned value).

[ngeorge1098]

Add assignment mismatch of the result of coshape() to a variable of type character

[ktras]

LGTM!

flang/test/Semantics/coshape.f90

+! RUN: %python %S/test_errors.py %s %flang_fc1
+! XFAIL: *
+! Check for semantic errors in coshape() function,
+! as defined in section 16.9.55 of the Fortran
+! 2018 standard
+
+program coshape_tests
+  use iso_c_binding, only : c_int32_t, c_int64_t
+  implicit none
+
+  integer array(1), non_coarray(1), scalar_coarray[*], array_coarray(1)[*], non_constant, scalar_result
+  real real_coarray[*]
+  complex complex_coarray[*]
+  character char_array(1)
+  logical non_integer, logical_coarray[*]
+  integer, allocatable :: codimensions(:)
+
+  !___ standard-conforming statement with no optional arguments present ___
+  codimensions = coshape(scalar_coarray)
+  codimensions = coshape(array_coarray)
+  codimensions = coshape(array_coarray(1))
+  codimensions = coshape(scalar_coarray[1])
+  codimensions = coshape(real_coarray)
+  codimensions = coshape(logical_coarray)
+  codimensions = coshape(complex_coarray)
+  codimensions = coshape(coarray=scalar_coarray)
+
+  !___ standard-conforming statements with optional kind argument present ___
+  codimensions = coshape(scalar_coarray, c_int32_t)
+  codimensions = coshape(real_coarray, kind=c_int32_t)
+  codimensions = coshape(coarray=logical_coarray, kind=c_int32_t)
+  codimensions = coshape(kind=c_int32_t, coarray=complex_coarray)
+
+  !___ non-conforming statements ___
+  ! coarray argument must be a coarray
+  codimensions = coshape(non_coarray)
+
+  ! kind argument must be an integer
+  codimensions = coshape(scalar_coarray, non_integer)
+
+  ! kind argument must be a constant expression
+  codimensions = coshape(real_coarray, non_constant)
+
+  ! kind argument must be an integer scalar
+  codimensions = coshape(complex_coarray, array)
+
+  ! missing all arguments
+  codimensions = coshape()
+
+  ! missing mandatory argument
+  codimensions = coshape(kind=c_int32_t)
+
+  ! incorrect typing for mandatory argument
+  codimensions = coshape(3.4)
+
+  ! incorrect typing for coarray argument
+  codimensions = coshape(coarray=3.4)
+
+  ! too many arguments
+  codimensions = coshape(scalar_coarray, c_int32_t, 0)
+
+  ! incorrect typing with correct keyword for coarray argument
+  codimensions = coshape(coarray=non_coarray)
+
+  ! correct typing with incorrect keyword for coarray argument
+  codimensions = coshape(c=real_coarray)
+
+  ! incorrect typing with correct keyword for kind argument
+  codimensions = coshape(complex_coarray, kind=non_integer)
+
+  ! correct typing with incorrect keyword for kind argument
+  codimensions = coshape(logical_coarray, kinds=c_int32_t)
+
+  ! repeated keyword for coarray argument
+  codimensions = coshape(coarray=scalar_coarray, coarray=real_coarray)
+
+  ! repeated keyword for kind argument
+  codimensions = coshape(real_coarray, kind=c_int32_t, kind=c_int64_t)
+
+  ! result must be a rank 1 array
+  scalar_result = coshape(scalar_coarray)
+
+  ! result must be an integer array
+  char_array = coshape(real_coarray)
+
+end program coshape_tests