Re: autoconf-2.61's AC_LINK_IFELSE with MinGW cross-compilers

[Ralf Wildenhues]

Hello Keith,

* Keith Marshall wrote on Fri, Mar 30, 2007 at 01:16:23AM CEST:
> On Thursday 29 March 2007 18:04, Ralf Wildenhues wrote:
> > * Chris Johns wrote on Thu, Mar 29, 2007 at 08:45:36AM CEST:
> > > The autoconf-2.61 release added a 'test -x' to AC_LINK_IFELSE and
> > > that has broken MinGW based cross-compilers using autoconf packages
> > > in MSYS.
> >
> > Not the one I'm using.  Debian testing's cross compiler package
> > i586-mingw32msvc-gcc chmod's its executable output to 0755.
> 
> With respect, that's not relevant.  Chris is not referring to a *nix 
> hosted compiler targetting MinGW; he's struggling with a Win32 hosted 
> RTEMS compiler suite, targetting various embedded platforms,

D'oh.  Upon reading it again I wonder how I could misread it that much.
Sorry.

> > Well, this is AFAIK the first bug report about this.
> 
> Well, that doesn't make it any less of a bug, and it's been introduced 
> only as of autoconf-2.61.

Sure.

> I'm curious as to the rationale behind this decision to insist of linker 
> output files to pass `test -x';

I don't think there exists any "insistence" except for having omitted
considering the case of a MinGW/MSYS -> $other cross build, when this
change was done.

> it must surely break cross-compilation 
> on any $build platform which doesn't conform to the Unix notion of what 
> designates a file as executable.  Can you point me to some 
> documentation which explains why it is necessary?

No.  But many platforms are pretty unixy in this respect.
And broken compilers or broken setups sometimes leave output files which
aren't executable, so testing that bit would have helped for them IIRC.

The fix should add a comment about this setup, so we don't forget again
why we cannot use -x.

Cheers,
Ralf