ChangeLog, README: Documented the `--with-nan-emulation' option.

diff --git a/ChangeLog b/ChangeLog
index b6eed3d5bf7ab195ffab66049c4b78bc83adaa81..79c117eadf5750dc54cc1b1768eb0c1ebd4ed08c 100644 (file)
--- 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 c39885da38fb4c0401426fc3012129393704e3f3..b639095dc2d316a40c25fe2edb8f01d731a555e8 100644 (file)
--- 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
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