Re: how can I do this in gmake?

[Maxim Yegorushkin]

ma wrote:

> I am writing a make file that will be used on several development. in each
> development, there are a huge amount of file that needed to be built but
> only a small part of them is changing and others are  not changing. I put
> all of these files into a library. The idea is that when the user run make
> file for the first time, it will create all of the source files and then
> create library and copy somewhere in the system. On any other call to this
> make file (maybe from some other directory that doesn't have  *.obj files
> related to library in it), it checks if the lib exist, use it and if not
> create it.

This may help you:

address@hidden tmp]$ cat Makefile
all :

libmy_obj := a.o b.o
lib/libmy.a : $(libmy_obj) | lib

foo_obj := foo.o
bin/foo : $(foo_obj) lib/libmy.a | bin
bin/foo : LDFLAGS += -Llib -lmy

bar_obj := bar.o
bin/bar : $(bar_obj) lib/libmy.a | bin
bin/bar : LDFLAGS += -Llib -lmy

bin/% :
        $(CC) -o $@ $($(@F)_obj) $(LDFLAGS)

lib/% :
        ar r $@ $($(@F)_obj)

.PHONY : all clean

all : lib/libmy.a bin/foo bin/bar

lib bin :
        mkdir -p $@

clean :
        rm -rf *.{c,o} lib bin

# create dummy source files
a.c b.c :
        touch $@
%.c :
        echo "int main() {}" > $@

address@hidden tmp]$ make
touch a.c
cc    -c -o a.o a.c
touch b.c
cc    -c -o b.o b.c
mkdir -p lib
ar r lib/libmy.a
ar: creating lib/libmy.a
echo "int main() {}" > foo.c
cc    -c -o foo.o foo.c
mkdir -p bin
cc -o bin/foo foo.o -Llib -lmy
echo "int main() {}" > bar.c
cc    -c -o bar.o bar.c
cc -o bin/bar bar.o -Llib -lmy
rm bar.c foo.c
address@hidden tmp]$ make bin/foo
make: `bin/foo' is up to date.
address@hidden tmp]$ rm lib/libmy.a
address@hidden tmp]$ make bin/foo
ar r lib/libmy.a
ar: creating lib/libmy.a
cc -o bin/foo foo.o -Llib -lmy