Re: dependencies for sources in sub dirs.

[Tobias Grimm <listaccount@xxxxxxxxxx>]

John Love-Jensen wrote:
> mkdir src
> vi src/Foo.c
> (put in something simple:  int foo() { return 3; } )
> gcc -c src/Foo.c
>
> Does the Foo.o end up in your current working directory, or in src/Foo.o?
>   

In this case, Foo.o is created in ./ instead of src/. But in my 
makefile, I force output with "-o" to src/Foo.o. (See example below).

As a short-hand solution, I modify the dependencies with Sed to prefix 
the target with the full path of the first dependent source:

sed "s/.*: \([^ ]*\/\).*/\1\0/"

This works,  but I thought there might be a way to instruct gcc to 
create the dependencies right in the first place.

Here's the small example:

src/foo.cc:
   #include "bar.h"

   int main()
   {
       return 0;
   }

src/bar.h:
   // EMPTY

Makefile:
   SRCS  = src/foo.c
   OBJS := $(addsuffix .o,$(basename ${SRCS}))

   %.o: %.cc
           gcc $< -o $@

   .dependencies: Makefile
           @gcc -MM -MG $(SRCS) > $@

   -include .dependencies

   test:$(OBJS)
           gcc $(OBJS) -o $@

   clean:
           @-rm -f $(OBJS) .dependencies test

Tobias