Hello David, * David Byron wrote on Fri, Jan 22, 2010 at 12:38:03AM CET: > Let's say I have a header file named foo.h that contains: > > #define FOO an_interesting_value > > (I think) I'm looking for a macro like this: > > AC_GET_VALUE([foo.h],[FOO]) > > that populates ac_cv_value_of_FOO with an_interesting_value > > Does such a macro exist? Apologies if this is a FAQ. I can think of a way > to do this by compiling a program that writes the result to a file, but that > seems complicated and a struggle when cross-compiling. There is AC_COMPUTE_INT which allows you to compute the integer (signed long) value of an arbitrary compile-time expression. It is a bit overkill for your case (in a cross-compile situation, it may need up to log_2(value) compilations to find the value), but should work nonetheless. Autoconf provides AC_EGREP_CPP but that doesn't let you get at the matched string. I think we should add something like this, or allow AC_PREPROC_IFELSE to store its output for inspection in the IF-TRUE branch. cpp -dM is not portable to non-GCC compilers. Thanks for the report. Cheers, Ralf _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
