Re: confusing ifeq behavior

[Paul D. Smith]

%% <address@hidden> writes:

  c> $(ALL_BLOCKS):
  c>       @echo "the target is ->$@<-"
  c> ifeq  ($@, $(filter $@, $(SOME_BLOCKS)))
  c>       @echo "yes ->$@<=>$(filter $@, $(SOME_BLOCKS))<-"
  c> else
  c>       @echo "no  ->$@<=>$(filter $@, $(SOME_BLOCKS))<-"
  c> endif

You can't do that.

Preprocessor commands like ifeq (as with the C preprocessor) are expanded
as the makefile is parsed.

Automatic variables like $@ are not valid until much later, when make
tries to execute the command script.

In this context $@ will ALWAYS be empty.


You have to either use a shell if statement to test $@, or use the $(if
...) function inside the command script.

-- 
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 Paul D. Smith <address@hidden>          Find some GNU make tips at:
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 "Please remain calm...I may be mad, but I am a professional." --Mad Scientist