Re: Multiple expansion works in rules, but not in actions

[Alexander Kriegisch]

Forgive me, I sent the wrong example and it is not really about multiple
expansion but about changing values:

FOO:=bla

$(FOO):
        @echo "## $(FOO) ##"

FOO:=

The target name $(FOO) is expanded to "bla", but $(FOO) is expanded to
nothing inside the action. I studied the manual of GNU make 3.81, but
found no explanation for this effect. Can you point me to the section I
should read in order to unserstand how changing values affect actions?
--
Alexander Kriegisch



> Can anybody explain why this does not work?
> 
> FOO=bla
> BAR=blu
> 
> $($(FOO)_xxx): baz
>       @echo "$($(FOO)_xxx)"
> 
> Multiple expansion works for the target definition and possible
> prerequisites, but not for the echo or any other shell commands inside
> actions. Is this a bug or a feature? Can I somehow use multiple
> expansion in an action?