After release 2.59c `AC_PROG_CC' change <(autoconf) Guidelines> changed its recommendation how to specify exit status for test program from > Test programs should `exit', not `return', from `main', because on > some systems (old Suns, at least) the argument to `return' in `main' > is ignored. to > Unless you arrange for `exit' to be declared, test > programs should `return', not `exit', from `main', because on many > systems `exit' is not declared by default. Worse, among tests bundled with autoconf finding no one to determine whether the argument to `return' in `main' is ignored, and, if yes, how to call `exit' properly. This effectively removes support for systems with that ignoring, requring `return' in `main' to work properly, and undermining the very purpose of autoconf as set forth in <(autoconf) Shell Script Compiler>: > `configure' must run on all those systems, and thus `configure' must > limit itself to their lowest common denominator of features. (That particular sentence is about shell code, but certainly bare working shell code is worthless unless checks it does are useful.) That systems ignoring `return' value are now rare is not a reason to do so. After all, systems which default shell has no functions are even more rare. Most likely in all systems where `return' works properly shell also has functions. (Please tell me if you know otherwise.) So restricting use of autoconf to systems with proper `return' obviates vast majority of the uses of m4 in autoconf, and very much of autoconf complexity. Thus excluding such a "rare" systems means completely different autoconf design. A reasonable solution would be standard tests as described above: whether the argument to `return' in `main' is ignored, and, if yes, how to call `exit' properly. Using it may even add some complexity to user package, like distributing additional header file and `#include' it (or even additonal m4 macro call) in test program code. (So that said header files checks for values accumulated in `confdefs.h', declares `exit' as necessary defines macro that sets exit status as appropriatte on this particular system.) Have no systems with broken `return' at hand, not even any detailed description of how that broken `return' would behave to test for, so can not tell more about how these standard exit status setting tests will work, let alone suggest code for them. _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
