RFA: fix PR bootstrap/58572

[Jeff Law]

On 11/15/13 11:26, Tom Tromey wrote:
> PR bootstrap/58572 was inadvertently caused by the automatic dependency
> patch series.
>
> The symptoms are that "make bootstrap-lean" will cause a subsequent
> "make install" to fail.
>
> The bug is that the automatic dependency code is picking up in-tree
> dependencies that were omitted by the old manual dependency tracking.
> You can see this by grepping for "libstdc" in $build/gcc/.deps/*.
>
> However, the "compare" step of "make bootstrap-lean" removes the
> previous build tree.  This causes these dependencies to be unresolved,
> and "make" thinks that the objects need to be rebuilt.  This rebuild is
> done with the system compiler, causing errors.
>
> This patch fixes the bug by removing the previous-stage-removal code
> from the top-level "compare" target.
>
> Tested by "make boostrap-clean; make install".
>
> Let me know what you think.
>
> Tom
>
> 2013-11-15  Tom Tromey  <tromey@redhat.com>
>
> 	PR bootstrap/58572:
> 	* Makefile.in: Rebuild.
> 	* Makefile.tpl ([+compare-target+]): Don't remove previous stage.
But isn't the whole point of bootstrap-lean to remove those directories 
during the build?

jeff