From: Florian Forster Date: Tue, 19 Jun 2007 19:29:25 +0000 (+0200) Subject: ChangeLog, README: Documented the `--with-nan-emulation' option. X-Git-Tag: collectd-4.0.3~1 X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=a0820b78b4fb1bf6dc591efe128028dba24233ce;p=collectd.git ChangeLog, README: Documented the `--with-nan-emulation' option. --- diff --git a/ChangeLog b/ChangeLog index b6eed3d5..79c117ea 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,8 +1,9 @@ -2007-06-18, Version 4.0.3 +2007-06-19, Version 4.0.3 * cpu plugin: Fix the Darwin / Mac OS X code. * ping plugin: Use the return value of `getpid', not its address. * csv, rrdtool plugin: Fixed a bug that prevented an buffer to be initialized correctly. + * configure: Added `--with-nan-emulation' to aid cross compilation. 2007-06-12, Version 4.0.2 * hddtemp and ntpd plugin: Corrected the parsing of port numbers when diff --git a/README b/README index c39885da..b639095d 100644 --- a/README +++ b/README @@ -275,6 +275,26 @@ Prerequisites For compiling on Darwin in general and the `apple_sensors' plugin in particular. + +Crosscompiling +-------------- + + To compile correctly collectd needs to be able to initialize static + variables to NAN (Not A Number). Some C libraries, especially the GNU + libc, have a problem with that. + + Luckily, with GCC it's possible to work around that problem: One can define + NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this + ``implementation'' the configure script needs to compile and run a short + test program. Obviously running a test program when doing a cross- + compilation is, well, challenging. + + If you run into this problem, you can use the `--with-nan-emulation' + configure option to force the use of this implementation. We can't promise + that the compiled binary actually behaves as it should, but since NANs + are likely never passed to the libm you have a good chance to be lucky. + + Author ------