Re: Preprocessing files with make

[Michael Chastain]

erik.cato@japro.se (Erik Cato) wrote:
> #------------------------------------------------------
> VPATH    = $(COMMON_SRC_DIRS) 
> SRCS     = $(foreach dir,$(VPATH),$(wildcard $(dir)/*.c))
> PREPROCS = $(notdir $(patsubst %.c,%.d,$(SRCS)))

So far so good.

Now you have a list of SRCS, such as "alpha.c beta.c gamma.c"
and a list of PREPROCS, such as "alpha.d beta.d gamma.d".
And you want "make" to behave as if you had these dependencies:

  alpha.d: alpha.c
  beta.d: beta.c
  gamma.d: gamma.c

I don't know how to do that either.  If anybody does know,
I'd like to know, too!

Gnu Make supports pattern rules with '%' in them:

  %.d: %.c

However this is not as flexible, and pattern rules interact poorly
if you have another dependency rules for the same files.

Michael