On Fri, May 16, 2014 at 11:19:58AM -0400, Nick Bowler wrote: > Some comments... Thanks. > On 2014-05-16 02:33 +0200, Thomas Klausner wrote: > > Hi Eric! > > > > On Wed, Apr 30, 2014 at 06:51:23PM -0600, Eric Blake wrote: > > > On 04/30/2014 06:12 PM, Thomas Klausner wrote: > [...] > > > > I'd like to test for the difference int <-> size_t in a configure > > > > script so I can get integer type/sign conversion-warnings free code on > > > > all these operating systems. > > > > > > > > I'm however not sure how to do this. Does anyone have a suggestion? > [...] > > Here's what I came up with: > > AC_CACHE_CHECK([parameter type for backtrace()], > > [am_cv_proto_backtrace_type], > > The am_cv_ prefix is used by Automake so I suggest choosing a > different one. What do you suggest using as prefixes? > > [AC_COMPILE_IFELSE( > > [AC_LANG_PROGRAM( > > [[ > > #include <execinfo.h> > > extern > > #ifdef __cplusplus > > "C" > > #endif > > size_t backtrace(void **addrlist, size_t len); > > ]]) > > ], > > [am_cv_proto_backtrace_type=size_t], > > [am_cv_proto_backtrace_type=int]) > > So if the compilation fails for any reason, you set the type to int. > That could be OK in your case (depending how you use it) but it seems > a little weird to me. I have a separate backtrace() test before that: AC_SEARCH_LIBS([backtrace], [execinfo], [ AC_DEFINE([HAVE_BACKTRACE], [1], [Define to 1 if you have the `backtrace' function.]) ], []) I could make the backtrace type test have three results, int, size_t, and FAILED, but I'm not sure if it really would serve a purpose. What kind of errors do you expect? > > ]) > > AC_DEFINE_UNQUOTED([backtrace_t], [$am_cv_proto_backtrace_type], > > [Define to return type for backtrace().]) > > Note that POSIX reserves identifiers ending in _t if you include any > header file, so you should normally avoid using that suffix in an > application. Ok, thanks for the note. Suggestions on how to improve it? Thomas _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
