Re: gmake and passing variables

[Paul D. Smith]

%% Joerg Krautwurst-Schmid <address@hidden> writes:

  jk> I use gmake to call another build process (ant) to compile and
  jk> build java classes. Now I want to pass a special option (e.g
  jk> debug) to ant.  But I don't know how to do this ? Is there a
  jk> chance to pass options from the commandline and handle them in the
  jk> Makefile or do I have to use environment variables to do this and
  jk> check if the variable is set etc.

The only way to do this is by setting a make variable on the command
line.

For example, suppose your makefile has:

  ANT       = ant
  ANTFLAGS  = -foo

    ... $(ANT) ($ANTFLAGS) -o $@ $<

(note I completely made up this syntax, I don't know anything about ant :)

Then, you could invoke make as:

  make ANTFLAGS='-foo -bar'

to override that setting and change the flags passed to ant.  You don't
have to test for this at all: command-line variable settings always take
precedence over variable settings in the makefile.


See the GNU make manual, section "Overriding Variables".

-- 
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 Paul D. Smith <address@hidden>          Find some GNU make tips at:
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