using AC_PROG_CC conditionnaly

[Patrice Dumas]

Hello,

I have a fortran package but in some case I also need a C compiler to detect
some C stuff to link with C libraries when there is no equivalent fortran 
library. I don't want a missing C compiler to lead to a configure failure,
however. It is also an automake based package. The following doesn't work,

if test $use_c_libraries_if_fortran_not_found = yes; then
        AC_PROG_CC
        .....test for C libraries
fi

I get
configure: error: conditional "AMDEP" was never defined.
Usually this means the macro was only invoked conditionally.

There is no possibility of doing something conditionnaly on AC_PROG_CC 
failing, either, like what can be done with most other macros:

AC_PROG_CC(,[.....test for C libraries], [c_compiler_found=no])

I think that one of those possibility (both?) should be available, and I 
think I favor AC_PROG_CC doing something when failing.

By chance are you aware of a possible workaround?

Pat