Re: gcc 3.3.4 cross build for mipsel mischooses the `as' to run

[James E Wilson <wilson at specifixinc dot com>]

Zack Weinberg wrote:
> This is a nice theory, but in practice I find that on any system where
> there's a choice between (GNU as and/or ld) and (the system-provided
> as and/or ld)

I was talking about cross compilers, though I probably didn't make that 
clear enough.  The rules are different for natives as you suggest.

For a native, if MD_EXEC_PREFIX is set, as it is for solaris2 and other 
svr4 targets, then MD_EXEC_PREFIX overrides the rules I described. 
MD_EXEC_PREFIX is added to exec_prefixes before tooldir_prefix.  Thus 
you need to do something explicit to override MD_EXEC_PREFIX if you want 
to use GNU as.

If MD_EXEC_PREFIX is not set, then for a native, we will find GNU as if 
it is installed, otherwise, we will search the user's path to find the 
native as.

MD_EXEC_PREFIX is useful if the native as is in a directory that 
normally will not be on the user's path, e.g. /usr/ccs/bin in the case 
of solaris.  MD_EXEC_PREFIX is also useful if you have dot (.) in your 
path, and you are doing a combined tree build.  In that case, 
MD_EXEC_PREFIX will prevent the native gcc from using ./as in the gcc 
directory.  However, I'd suggest that removing dot (.) from your path is 
the better solution.  Most targets do not set MD_EXEC_PREFIX.

If MD_EXEC_PREFIX is a problem, we could perhaps fix it by moving it 
after the tooldir_prefix code.  Thus we would look for GNU as before we 
look for the native as.  However, this might break configure for people 
who did not specify --with-gnu-as, as now they may be using it when they 
did not intend to.

Another possible solution would be disable use of MD_EXEC_PREFIX when 
--with-gnu-as is specified.  We probably still want to add it to 
startfile_prefixes, but we could avoid adding it to exec_prefixes.  That 
might actually be a very good solution, as this means gcc will 
automatically find the native as if you did not specify --with-gnu-as, 
and will automatically find GNU as if you did specify --with-gnu-as 
which is the behaviour we want.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com