Re: selection or target tools

[Gunther Nikl <gni at gecko dot de>]

On Thu, Dec 22, 2005 at 11:39:20AM -0500, Daniel Jacobowitz wrote:
> On Thu, Dec 22, 2005 at 05:34:14PM +0100, Gunther Nikl wrote:
> > Hello!
> > 
> > The new scheme to select target tools breaks building GCC for me. Maybe I
> > have an unusal setup. The problem in my case is that configure now chooses
> > tools from $prefix/bin. It did use tools from $prefix/$target/bin before.
> > On my setup I have *different* tools in those places. Until know the tools
> > from $prefix/$target/bin were selected and everything was fine. Now the
> > build process creates eg. gcc/as which uses as from $prefix/bin. That
> > assembler is *never* invoked when I running <target>-gcc. Thus I am
> > surprised that configure now prefers that version. Is the current
> > behaviour a bug?
> 
> From your description I assume this is a native build ($target ==
> $host).  When did this change?

Sorry for being vague, its a cross-compiler (build == host). The build
errors out for libgcc.a since gcc/xgcc uses the "wrong" assembler. The
last successful build was at the beginning of decemeber.

> Also, _why_ do you have different tools in those two places?

Is this important? I kept binutil versions in $prefix/bin because at
times its useful to have it, eg. comparing its output/behaviour. The
replaced tools in $prefix/$target/bin are better suited for my needs,
thus I installed them there and until recently GCC always used these
tools.

> It looks to me like this last changed around 2005-06-16 on HEAD, and we
> assume that the assembler installed in $prefix is the assembler you
> want the compiler to be using - it's the same assembler you'd get if 
> you said "as", so why shouldn't we use it?

I rarely invoke eg. the assembler manually. Most of the time I use the
compiler frontend (gcc) since that is much more convenient. All GCC
version I know use $prefix/$target/bin/<tool> if its available, at least
for assembler and linker. I never seen the frontend using $target-<tool>.

On Thu, Dec 22, 2005 at 12:16:46PM -0500, Daniel Jacobowitz wrote:
> On Thu, Dec 22, 2005 at 06:13:22PM +0100, Paolo Bonzini wrote:
> > I am a bit confused.
> > 
> > Does Gunther's failure mean that the default for the proposed 
> > --with-build-tools option, should be $prefix/$target/bin?  This would 
> > set AS_FOR_TARGET, etc. from within the GCC_TARGET_TOOL toplevel 
> > configure macro, and percolate all the way down to gcc.

That would probaly restore previous behaviour since it would prefer tools
in $prefix/$target/bin over $prefix/bin.

> If I am following correctly:
> 
> The assembler we test for features in Gunther's case has always been
> $prefix/bin/as - luckily harmless for him and he probably never
> noticed.  The installed compiler uses $prefix/$target/bin/as. The
> being-built compiler has switched from one to the other.

Your analysis seems to be correct. I noticed that "wrong" tools (as/ld)
were tested by configure but that was non-problematic. The new behaviour
is since now a tool is invoked with wrong options.

> One appropriate default for --with-build-tools could be the same as
> the defaults for --program-transform-name.  A default native build
> would use 'as', a default cross build would use '$target-as'.  Most
> people using --program-prefix would probably also pass the same value
> to --with-build-tools.

That would not solve the problem. However, Paolo suggestion 2) in another
mail (http://gcc.gnu.org/ml/gcc/2005-12/msg00688.html) seems to restore
old behaviour and thus fix my issue.

Gunther