Re: target variable ($@) as prerequisite

[Oleksandr Gavenko]

On 27.01.2011 11:59, ulugutz wrote:
> nope i am right. every target has the same dependency list. you agree with
> that, right?
For which rules. In written code

PNG_FILES := $(wildcard *.png)
PDF_FILES := $(PNG_FILES:.png=.pdf)

.PHONY: all
all: $(PDF_FILES)

%.pdf: %.png
    cp $*.png $@

See what happen:

  $ touch 1.png 2.png
  $ make
cp 1.png 1.pdf
cp 2.png 2.pdf
  $ LANG=C make
make: Nothing to be done for `all'.
  $ touch 2.png
  $ make
 cp 2.png 2.pdf

Only one 'cp' operation take place in last case.

> so if one timestamp of the dependencies changes all PDFs are
> out of date :-/
Your case possible if write such dependency:

1.pdf 2.pdf: 1.png 2.png

> i want to have only the png associated to the target in the dependency list.
See top description.

Or may be you need explain where I don't understand you.

--
С уважением, Александр Гавенко.