Hi, On Fri, May 27, 2005 at 12:15:33PM +0100, Keith MARSHALL wrote: > > But if you port to a new or very weird platform, you can have problems > > running configure there. Then it comes handy that you take the > > template and fill in the info, or correct the mistakes in config.h. actually, I was slightly wrong. In this situation you fill in config.h.in, you don't edit config.h. > [...], after a *successful* run of configure had left HAVE_TERMIOS_H > undefined. Another list subscriber had suggested that it he *needed* to > edit config.h to fix this, because he did have termios.h, and configure > got it wrong. [...] Well, if configure really got something wrong, it makes sense to edit config.h, fix the mistake. I just don't think this happens every year. And if it is so exceptional, I think it shouldn't be adviced in manual, and it wasn't a good advice on the list. "Show me config.log" would be much better answer. Actually, when I think about it, there is also the oposite situation: you don't want to use foo, yet ./configure detects it. If there is no --disable-foo, and you cannot edit configure.ac (perhaps you don't have the exect version which the maintainer used to cook his version), you can edit config.h to #undef HAVE_FOO. That has better chance to succeed. And you asked: > BTW, why does the "#undef HAVE_SOMEHEADER_H" in config.h.in get wrapped > in comment marks, when it is copied into config.h? The following comment is part of every ./configure script (it originates in /usr/share/autoconf/autoconf/status.m4): # This sed command replaces #undef with comments. This is necessary, for # example, in the case of _POSIX_SOURCE, which is predefined and required # on some systems where configure will not decide to define it. So this is kind of hack, but it would be too risky to try to change it now. > Or, do some [broken] compilers choke on "#undef AN_UNDEFINED_SYMBOL"? So your guess wasn't right. > Does it not make more sense to forcibly ensure that HAVE_SOMEHEADER_H is > not defined, if configure has determined that someheader.h isn't present? You say ``forcibly.'' I don't think you have to use force here. config.h is usually included as the very first include, so there is no place where the symbol should be predefined. Have a nice day, Stepan Kasal _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
