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While searching for the usage of .PHONY in makefile, i came accross this which says something like

.PHONY also allows you to have targets that do not have an associated rule

I put the example metioned in that post in a makefile and I ran that but it is not showing me any error as mentioned in the OP. Can someone please detail it?

The makefile

target1: dostuff

.PHONY: target2
target2: dostuff



dostuff:
        @echo "Stuff gets done!!!!"

O/P

[sourav@titan temp]$ make target1
Stuff gets done!!!!
[sourav@titan temp]$ make target2
Stuff gets done!!!!
[sourav@titan temp]$ make
Stuff gets done!!!!
[sourav@titan temp]$

As per the OP, make target1 should throw an error. Please enlight.

Some Info

[sourav@titan temp]$ uname -r
2.6.18-194.el5PAE
[sourav@titan temp]$ make --version
GNU Make 3.81
[sourav@titan temp]$
Community
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Sourav Ghosh
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    That comment is wrong. – MadScientist Dec 03 '13 at 13:18
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    [ PDF file inbound ] http://www.gnu.org/software/make/manual/make.pdf section `4.5` – user2485710 Dec 03 '13 at 13:18
  • @dbw Sir, i'm new to linux. Can you please explain? – Sourav Ghosh Dec 03 '13 at 13:34
  • He linked you to the make manual wherein you can read about how .PHONY works. And to clarify @MadScientist's comment the poster of the comment is wrong. make allows targets without rules just fine regardless of .PHONY. make will not throw the error the poster of that comment indicated it would as your testing has shown. – Etan Reisner Dec 03 '13 at 14:01

1 Answers1

3

True. A .PHONY target can have only dependencies, without any rule. In this case, make will not execute any rule, but will check if the dependencies are satisfied (and, if not, will execute their rules).

Therefore, in your example, it is correct that both target1 and target2 call dostuff because it is a dependency.

Claudio
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  • Why should you have an error ? According to the documentation, phony targets (like `target1`) can either have or not have a rule. In your case, `target1` does not have an rule. It only has dependencies. But this is not an error. – Claudio Dec 03 '13 at 15:18