[vsipl++] [patch] fix for generating ALF dependencies

[Jules Bergmann]

Don McCoy wrote:
> This patch corrects a problem generating the dependencies for ALF source 
> files when building for Cell/B.E.  The problem did not affect the way 
> the source files were built, but the fix eliminates an error complaining 
> about missing header files.
> 
> Ok to commit?

Sorry for the late review, I know this has already been checked in.

It looks like this moves the C dependency rule from the top-level 
makefile to the ALF makefile, and customizes it for the ALF flags.  IIUC 
This only works if the only C files we have in the library are for ALF 
(which is currently the case -- we C files in FFTW, ATLAS, and CLAPACK, 
but they get built with separate makefiles).

In retrospect, we should either:
  - qualify this rule to only apply for C files in ALF, or
  - keep the original general rule and use the fancy per-directory 
variable thing "$(call dir_var,$(dir $<),CFLAGS)" to use the ALF flags 
for C files in the ALF directories.

I think the former solution is the easiest (and it is consistent with 
how we build the ALF C files).  Replacing:

> +%.d: %.c
> +	$(make_alf_dep)
> +

With:

	alf_depends := $(patsubst $(srcdir)/%.c, %.d, $(alf_src))

	$(alf_depends): %d: %c
		$(make_alf_dep)

should do the trick.

Does that sound OK?

If so, I'll fold it into a patch that fixes C++ dependencies on MCOE.

(This is purely defensive programming -- we've gone 2+ years before 
adding C files to the library, it will probably be another 2+ years 
before we add more and really have to fix this!)

				-- Jules

-- 
Jules Bergmann
CodeSourcery
jules at codesourcery.com
(650) 331-3385 x705