RE: Object & changing target of CXXCOM

[Johan Holmberg]

On Fri, 15 Jun 2001, Gary Oberbrunner wrote:
>
> Steven Allen writes:
>
>  > I guess I think of it as I should be able to say
>  >
>  > Objects $env "file.cpp", 'foo.cpp';
>  >    or
>  > Objects $env "file.cpp" => "../../obj/file.o",
>  >             "foo.cpp" => "../../obj/foo.o";
>

> I'd also like to be able to do this (the above syntax doesn't
> work, but something could be worked out -- maybe just for one
> object at a time).  Just yesterday I wanted to build a little
> test program using a few of my sources, built with different cmd
> line options (-DTEST_MODE); the obvious thing of just defining a
> new environment with -DTEST_MODE in it and using Program doesn't
> work, because the objects are built twice with different
> options.

I have also felt that it is too complicated to do these things.
Therefore I added functionality to make it easier in my "Cons::Plus"
module. There I can direct where object files are placed in two
new ways:

1) use the new method "ObjectsInDir":

     use Cons::Plus;
     $y1 = Cons::Plus->new(CFLAGS => "-DVARIANT1");
     $y2 = Cons::Plus->new(CFLAGS => "-DVARIANT2");

     @objs1 = $y1->ObjectsInDir('myprog.c', 'mylib.c', 'some-dir-1');
     $y1->Program('myprog-1', @objs1);

     @objs2 = $y2->ObjectsInDir('myprog.c', 'mylib.c', 'some-dir-2');
     $y2->Program('myprog-2', @objs2);

   'ObjectsInDir' works like 'Objects', but places the object files
   in the directory specified as last argument. So the directory
   layout in the example will be:

     $ cons . -p
     myprog-1
     myprog-2
     some-dir-1/mylib.o
     some-dir-1/myprog.o
     some-dir-2/mylib.o
     some-dir-2/myprog.o

2) use the variable 'BUILD_TOP'. It is understood by 'Cons::Plus::Program'
   and 'Cons::Plus::Objects', and works almost like the 'Link' command
   (but without any hard links or copying):

     use Cons::Plus;

     $x1 = Cons::Plus->new(BUILD_TOP => "variant1",
                           CFLAGS    => "-DVARIANT1" );
     $x2 = Cons::Plus->new(BUILD_TOP => "variant2",
                           CFLAGS    => "-DVARIANT2" );

     $x1->Program('myprog', 'myprog.c', 'mylib.c');
     $x2->Program('myprog', 'myprog.c', 'mylib.c');

  In this case we get the following layout:

     $ cons . -p
     variant1/mylib.o
     variant1/myprog
     variant1/myprog.o
     variant2/mylib.o
     variant2/myprog
     variant2/myprog.o


If anyone is interested in  Cons::Plus, it is available from
ftp://mercury.iar.se/jhftp/cons/ (I also mentioned it in a mail to
the list on April 4).


/Johan Holmberg