Re: ifeq in gmake

[Paul D. Smith]

%% "atteson" <kevin@atteson.com> writes:

  a> Can someone explain why gmake outputs "goodbye" rather than "hello"
  a> with the following test makefile:

  a> %.a : b
  a> ifeq ($@,"a.a")
  a>     echo "hello"
  a> else
  a>     echo "goodbye"
  a> endif

Because, ifeq etc. are evaluated as make is reading in the makefile
(even if they seem to appear in a "rule context": ONLY lines beginning
with TAB are considered command scripts and passed to the shell.

On the other hand, automatic variables like $@ are set only when make is
trying to build the rules long after the makefiles have been read in.

So, $@ is always empty when you evaluate that ifeq.

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