Re: append to/from command line variable

[Paul D. Smith]

%% "Martin d'Anjou" <address@hidden> writes:

  md> I read that it is not possible to append to a variable from the
  md> command line:
  md> http://lists.gnu.org/archive/html/help-make/2003-02/msg00001.html

  md> How hard is it to modify the source code to acheive this anyway?

The problem is, what does it mean to append to a variable from the
command line?

When do you append it?  To what value?  In other words, given the
following makefile:

    $(warning FOO = $(FOO))

    FOO := bar

    $(warning FOO = $(FOO))

    FOO += biz

    $(warning FOO = $(FOO))

    all: FOO := boz
    all: FOO += baz
    all: ; @echo FOO = $(FOO) / '$$FOO' = $$FOO

What does make print out when you run:

    make FOO+=foo

??

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