Re: $(eval) and shell variables help

[Anoni]

I am using $(eval) to dynamically generate a set of rules (one for each
source file/targets) and need to prevent the Make from updating the target
(using touch)
if there is an error detected from a command I executed as part of the rule.
Is there a way to do this?


Thanks.

----- Original Message -----
From: "Paul D. Smith" <address@hidden>
To: "Anoni" <address@hidden>
Cc: <address@hidden>
Sent: Wednesday, November 20, 2002 12:38 PM
Subject: Re: $(eval) and shell variables help


> %% "Anoni" <address@hidden> writes:
>
>   a> How do you get the value of a shell variable (e.g, exit number) in an
>   a> $(eval) context?
>
> I think you're confused about what eval does.
>
> It does not _run_ a makefile.  It only evaluates it: reads it in so that
> it's now part of make's internal database.
>
>   a> define TEMPLATE
>
>   a>     $(1)     : blah blah...; \
>   a>             @some_command; \
>   a>                exit_status=...; \
>   a>                if [ ... != 0 ]; then \
>   a>                      exit 1; \
>   a>                 fi; \
>   a>             touch $$@;
>   a> endef
>
>   a> $(foreach t,$(targets),$(eval $(call TEMPLATE,$(t))))
>
> This identical to writing the contents of the TEMPLATE variable out by
> hand, once for each word in $(targets).
>
> Neither more nor less.
>
> Maybe if you described what you were actually trying to do we could give
> you better advice.
>
> --
> --------------------------------------------------------------------------
-----
>  Paul D. Smith <address@hidden>          Find some GNU make tips at:
>  http://www.gnu.org                      http://make.paulandlesley.org
>  "Please remain calm...I may be mad, but I am a professional." --Mad
Scientist
>
>
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