As Fortran 2018 18.2.3.3, the intrinsic module procedure
C_F_POINTER(CPTR, FPTR [, SHAPE]) associates a data pointer with the
target of a C pointer and specify its shape. CPTR shall be a scalar of
type C_PTR, and its value is the C address or the result of a reference
to C_LOC. FPTR is one pointer, either scalar or array. SHAPE is a
rank-one integer array, and it shall be present if and only if FPTR is
an array.
C_PTR is the derived type with only one component of integer 64, and the
integer 64 component value is the address. Build the right "source"
fir::ExtendedValue based on the address and shape, and use
associateMutableBox to associate the pointer with the target of the C
pointer.
Refactor the getting the address of C_PTR to reuse the code.
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D132303
As Fortran 2018 18.2.3.6, the intrinsic `c_loc(x)` gets the C address
of argument `x`. It returns the scalar of type C_PTR. As defined in
iso_c_binding in `flang/module/__fortran_builtins.f90`, C_PTR is the
derived type with only one component of integer 64.
This supports the lowering of intrinsic module procedure `c_loc` by
converting the address of argument into integer 64, where the argument
is lowered as Box and the address is generated using fir.box_addr.
The lowering of intrinsic `c_funloc` has the similar characteristic and
will be supported later.
The execution tests for various data types are in issue
https://github.com/llvm/llvm-project/issues/56552.
Reviewed By: Jean Perier
Differential Revision: https://reviews.llvm.org/D129659
Peixin Qiao