Date: Sat, 11 Jun 2011 01:33:42 +0200 From: grischka <[email protected]> Subject: Re: Named parameters in make? Message-ID: <[email protected]> Content-Type: text/plain; charset=UTF-8; format=flowed
>> Over my time using make I know I've read section 8.8 "The eval Function" a >> number of times. But the implication of this sentence didn't hit me until I >> saw your example: >> >> "The argument to the eval function is expanded, then the results of that >> expansion are parsed as makefile syntax." > >Reason why eval is difficult to understand is that there is no good >reason to have it, in the first place. > >For example one can write: > > all_rule = all : ; echo $$@ > $(all_rule) > >which expands the macro $(all_rule) and does parse the result as >makefile syntax. That is everything said in the above statement, >just without 'eval'. The only use I have for using $(eval) directly is setting a variable within a user-defined function, which is quite useful in some contexts. set=$(eval $1:=$2) I use this behavior of $(eval) quite frequently. Best regards, John D.
<<winmail.dat>>
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