GNU Make problem w/implicit rules and wildcard expansion

[Tobias Dussa]

Hi folks,

I've already posted this question to gnu.utils.help, but got no
response, so I've come here since I am unsure whether I am
dealing with a bug in Make or with my own stupidity.

Maybe I'm too blind to see it, but I can't figure out why this
won't work.

I have a document that depends on several other files that all
reside in a subdirectory with a similar name.  For instance,
consider this:

Doc a.tex depends on a/01.tex, a/02.tex,
doc b.tex depends on b/01.tex, b/02.tex, and so on.

Now, I tried to map this relationship into a Makefile with this
rule:

---
%.tex : %/*.tex
        do_whatever
---

This, unfortunately, won't work.  Running make -d yields

---
...
 Trying implicit prerequisite `a/*.tex'.
...
---

whereas correct expansion, for instance by a rule like

---
%.tex : a/*.tex
        do_whatever
---

(correctly) yields

---
 Trying rule prerequisite `a/01.tex'.
 Trying rule prerequisite `a/02.tex'.
---

Obviously, the wildcard isn't expanded when preceded by a
pattern-matching '%'.  However, I seem to be unable to find
any hints in the make docs (man page, info file) that state
why this is so.  So my question is: is this a bug or a feature?
And either way, does anyone have an idea for a workaround?

Oops, almost forgot, my make is GNU Make 3.80 on a
Slack 9.0 system.

Cheers,
Toby.
-- 
Why crawl through Windows when there are doors?