PATCH PING: distcc and ccache speedup: adds directives-only preprocessing
Mark Mitchell
mark@codesourcery.com
Thu Jul 26 07:16:00 GMT 2007
Ian Lance Taylor wrote:
> I would approve the patch if I could, but, unfortunately, since it
> adds a new option and a new way of reading files, it is probably
> non-algorithmic.
Algorithmic, I think you mean?
This patch is OK, with one caveat: I think the documentation could be
better.
> +@item -fdirectives-only
> +@opindex fdirectives-only
> +This option provides a simplified preprocessor to improve the
> +performance of distributed build systems such as distcc. It's
> +behavior depends on a number of other flags.
This paragraph doesn't say much. I think combining it with the next one
would be better:
With @option{-E}, limit preprocessing to the handling of directives
such as @code{#define}, @code{#ifdef}, and @code{#error}. Other
preprocessor operations, such as macro expansion and trigraph
conversion are not performed. In addition, as with @option{-dD},
macro definitions are included in the output.
> +If the @option{-fpreprocessed} option is enabled, it suppresses
> +predefinition of most builtin and command line macros. This
> +prevents duplicate definition of macros output with the @option{-E}
> +option.
I don't entirely understand this paragraph. Does this apply when -E is
in effect? Does it really suppress *most* macros, or *all* of them? If
some are not suppressed, *which* are not suppressed?
When the documentation is revised, I will review it -- or, Ian, you can
just review it and approve it, now that I've signed off on the body of
the patch.
Thanks,
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713
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