Hi all, First off, I'm not in the mailing list, so please CC replies to myself. Second, I am rather new to autoconf. I noticed a problem with the output of AC_PROG_CXX which I guess (but not yet sure) extends to others such as AC_PROG_CC, AC_PROG_CPP etc. The problem is that if you call AC_PROG_CXX, even if there are no C++ compilers, *CXX is set to g++ anyway* and the macro doesn't provide a means to understand if it actually succeeded or not. This is a problem because if you want to enable a feature only if a C++ compiler exists, you need to be able to well, check if there is a C++ compiler. This is the relevant Stack Overflow question: http://stackoverflow.com/q/27111000/912144 Now I'm by no means an expert with m4, but I think I could hack away at this. Before sending a patch however, I wanted to make sure if the idea is acceptable. My idea is to add a variable that simply says whether the test was successful or not. For example, ac_cv_prog_cc_g, ac_cv_prog_cc_c_o, ac_cv_prog_cc_c99 etc are used for various feature tests, so why not have these additional variables: - ac_cv_prog_cc set to yes if AC_PROG_CC succeeded (and therefore CC is valid) - ac_cv_prog_cpp set to yes if AC_PROG_CPP succeeded (and therefore CPP is valid) - ac_cv_prog_cxx set to yes if AC_PROG_CXX succeeded (and therefore CXX is valid) You get the idea! This addition would be completely backward-compatible since it doesn't remove anything and uses only reserved variable names. That is unless those variables are actually used and I don't know about it, then of course another name could be picked. Please let me know what you think, Shahbaz _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
