Re: autoconf-2.1.3

[Ian Lance Taylor]

address@hidden writes:

> So this is a suggestion, not a bug.  There is a lot of software that I
> cannot get to cross-compile because the configure script does a test
> which requires the compilation and running of some code.  Instead of
> expanding the macros to check if we are cross-compiling, and die with an
> error if we are, why not simply provide a standard environment variable
> for holding the name of the build machines compiler, and use that for
> the test?  Some projects have manually done this (CC_FOR_BUILD, or
> BUILD_CC - depending on the project).   Assuming the person doing the
> cross-compiling is intelligent enough to keep their normal compiler/libs
> and their cross compiler/libs at the same version, there should not be
> any problems with this.

Because that would normally do the wrong thing.

autoconf wants to test the characteristics of the host system, not the
build system.  Your suggestion would cause it to test the
characteristics of the build system.  That can in some cases be
correct, but in the general case it is not correct.

Consider a host system of Windows, and a build system of Linux, and a
test to see whether chown works to give away a file.  The result on
the build system tells you nothing about the host system.

For more on host systems and build systems, see my notes at
    http://www.airs.com/ian/configure/

Ian