Re: GNU Make feature request, pattern matching

[Marty Leisner]

It often is useful to give derived files special names
(like %-stage1.xml) so youf rule might be:

%-stage1.xml:   %.xml

Also in your example:

%.xml: $(src)/%.xml

you would also have a problem if $(srcdir) == $(objdir)

marty

Noah Slater <address@hidden> writes  on Tue, 30 Sep 2008 20:57:39 +01
00
     > Hey,
     > 
     > Thanks for the reply.
     > 
     > On Tue, Sep 30, 2008 at 03:08:18PM -0400, Paul Smith wrote:
     > > Have you considered using VPATH?  It looks to me (based on this 
example;
     > > I didn't try to get the tarball) that you have a good fit for it here.
     > > Try rewriting your rule like this:
     > >
     > >       VPATH := $(src)
     > >
     > >       %.html: %.txt
     > >               $(info example making $@ from $<)
     > >
     > > and see if that works.
     > 
     > I didn't know how much detail to go into in my original email, so I left 
quite a
     > lot of details out about why I've ended up in this situation. Sorry for 
any
     > confusion this may cause.
     > 
     > As for this particular idea, yeah, I tried that and it works perfectly.
     > 
     > Unfortunately there are also cases where a source file has to be moved 
to the
     > directory and processed along the way, perhaps to add metadata (such as 
author
     > name or copyright notices) or other information that my software knows 
about.
     > 
     > This results in rules such as:
     > 
     >   %.xml: %.xml
     > 
     > Clearly, this doesn't work because GNU Make correctly assumes they are 
the same.
     > 
     > Of course, with my previous suggestion, this would be written:
     > 
     >   %.xml: $(src)/%.xml
     > 
     > But this fails for the same reasons.
     > 
     > I am generating the targets dynamically (by scanning the source 
directory using
     > Python and using GNU Make's standard makefile generation hooks) and it 
seems I
     > that a possible solution is to do this:
     > 
     >   # this define is written verbatim in the core makefile
     > 
     >   define build_txt_html
     >     $(info stuff here)
     >   endef
     > 
     >   # these next too lines are from the generated makefile
     > 
     >   all: dir/index.html
     > 
     >   dir/index.html: $(src)/dir/index.txt; $(build_txt_html)
     > 
     > It seems that this would work, and the format of the "configuration" 
file is
     > untouched, but it does feel slightly un-make-like.
     > 
     > Your thoughts or feedback is very welcome.
     > 
     > Thanks,
     > 
     > -- 
     > Noah Slater, http://bytesexual.org/nslater
     > 
     > 
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