On Mon, 14 Apr 2008 14:59:14 +0200, Raphael Hertzog <[EMAIL PROTECTED]> said:
--8<---------------cut here---------------start------------->8---
1 | ifeq "$(wildcard ../include/factory++.hpp)" ""
2 | CPPFLAGS=`pkg-config libfactory++ --cflags`
3 | else
4 | INCLUDE = .$(shell ln -sf ../include factory++)
5 | CPPFLAGS = -I$(INCLUDE)
6 | CXXFLAGS += -O0 -g
7 | test_factory.o: $(wildcard $(INCLUDE)/factory++/*.hpp)
8 | endif
--8<---------------cut here---------------end--------------->8---
> While stracing the whole process, you'll discover that this shell
> snippet is executed twice... the first time it creates a "factory++"
> symlink pointing to ../include and the second time a symlink named
> include inside ../include pointing to ../include.
I can explain why it is executed twice. The commands run by
calls to the `shell' function are run when the function calls are
expanded. The expansion happens first on line 5: CPPFLAGS = -I$(INCLUDE)
Then it happens on line 7:
test_factory.o: $(wildcard $(INCLUDE)/factory++/*.hpp)
This is because the variable is set using the recursively
expanded method (using = ). Using a simply expanded variable (:=)
INCLUDE := $(shell ln -sf ../include factory++)
will expand the shell function only once.
manoj
--
The reason why worry kills more people than work is that more people
worry than work.
Manoj Srivastava <[EMAIL PROTECTED]> <http://www.debian.org/~srivasta/>
1024D/BF24424C print 4966 F272 D093 B493 410B 924B 21BA DABB BF24 424C
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
