Dear Lazyweb,
In my newest project I need to use Fortran routines and variables in C. From the source code point of view this requires only to declare the needed Fortran entities in your C code whilst taking the “right” types of the variables and the name mangling of the Fortran compiler into account.
Here is an example. Consider you have the following Fortran code:
module X real, dimension(0:1) :: v subroutine Foo(A, b, c, & & D) integer, intent(in) :: a, & & B real, intent(out) :: C, d ! <Foo's body> end subroutine end module X
To use the array v and the subroutine Foo() in C, you need to add (something like) the following declarations to your C source code:
extern float x_mp_v_[2]; void x_mp_foo_(int* a, int* b, float* c, float* d);
If only a handful of Fortran routines are needed to be called from C, declaring them by hand may be feasible. This is however error-prone and becomes impracticable for more than a handful of routines. Especially if the routine signatures change frequently.
So what I’d like to have is a tool that generates a C header file containing all declarations of Fortran entities from a given Fortran source file. Or if such tool does not exist, a tool that extracts variable declarations and routine signatures from a Fortran source file into a format that is easier to parse than Fortran itself would also be helpful. Any suggestions?
and a natural number 
. This can be easily understood. Just take the prime factors of an arbitrary natural number. If one of these prime factors is odd, the number can be written as a product of this odd prime factor and the product of the remaining prime factors (which can be even or odd). If there is no odd prime factor, all prime factors must be even and since 2 is the only even prime number the original number must be a power of 2.
