I have a module that will target several different operating systems and configurations. Sometimes, some C code can make this module's task a little easier, so I have some C functions that I would like to bind the code. I don't have to bind the C functions -- I can't guarantee that the end-user even has a C compiler, for instance, and it's generally not a problem to failover gracefully to a pure Perl way of accomplishing the same thing -- but it would be nice if I could call the C functions from the Perl script.

Still with me? Here's another tricky part. Just about all of the C code is system specific -- a function written for Windows won't compile on Linux and vice-versa, and the function that does a similar thing on Solaris will look totally different.

#include <some/Windows/headerfile.h>
int foo_for_Windows_c(int a,double b)
{
  do_windows_stuff();
  return 42;
}

#include <path/to/linux/headerfile.h>
int foo_for_linux_c(int a,double b)
{
  do_linux_stuff(7);
  return 42;
}

Furthermore, even for native code that targets the same system, it's possible that only some of them can be compiled on any particular configuration.

#include <some/headerfile/that/might/not/even/exist.h>
int bar_for_solaris_c(int a,double b)
{
  call_solaris_library_that_might_be_installed_here(11);
  return 19;
}

But ideally we could still use the C functions that would compile with that configuration. So my questions are:

• how can I compile C functions conditionally (compile only the code that is appropriate for the current value of $^O)?

• how can I compile C functions individually (some functions might not compile, but we still want to use the ones that can)?

• can I do this at build-time (while the end-user is installing the module) or at run-time (with Inline::C, for example)? Which way is better?

• how would I tell which functions were successfully compiled and are available for use from Perl?

All thoughts appreciated!