On 2012-07-25 19:21 +0200, Sven Joachim wrote: > Hello, > > I have been wondering¹ what the intended behavior of `configure' is if > both "--build" and "--host" are given and are identical. The manual > says > > ,---- > | They all default to the result of running `config.guess', unless you > | specify either `--build' or `--host'. In this case, the default > | becomes the system type you specified. If you specify both, and > | they're different, `configure' enters cross compilation mode, so it > | doesn't run any tests that require execution. > `---- > > This seems to imply "if they are not different, `configure' does not > enter cross compilation mode", and this is how it actually has been > behaving for the last twelve years. However, the manual also says OK, so according to your own tests, autoconf behaves as documented above when both --build and --host are specified, which is good. > ,---- > | Now, `configure' enters cross-compilation mode if and only if > | `--host' is passed. > `---- Given the rest of the document, and the actual behaviour of autoconf, I think this is simply a typo, and should read: Now, `configure' enters cross-compilation mode only if `--host' is passed. that is, configure will never enter cross compilation mode unless --host appears on the configure command line (although this is still not strictly true, since you can also enter cross compilation mode by setting cross_compiling=yes). In fact, just below the above quoted passage the document explains precisely what happens when only --host (and not --build) is specified: If you specify --host, but not --build, when configure performs the first compiler test it tries to run an executable produced by the compiler. If the execution fails, it enters cross-compilation mode. > contradicting that. What is the intended behavior that will be > implemented when hell freez^W^W autoconf 2.13 bug compatibility gets > finally removed? Presumably when the compatibility is removed, then --build will default to config.guess in all operating modes, the magic autodetection of cross compilation will go away, and we will all be happier for it. Cheers, -- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/) _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
