Le 28 janv. 2013 à 17:11, John P. Hartmann <jphartm...@gmail.com> a écrit :
> On 28 January 2013 16:43, John P. Hartmann <jphartm...@gmail.com> wrote:
>> But here is another one:
>>
>> | dotobyfors dotobyfor { listend($1, $2); }
>>
>> Gets "warning: unset value: $$".
>>
>> I'm relying on the default $$ = $1 here.
>>
>> Or is there something more subtle going on? Or (shudder) is the
>> default applied only when there is no explicit semantic code? (In
>> which case I have a lot of grammars to fix.)
>
> Adding $$ = $1 kept Bison quiet.
>
> Here is a variation that gets Unused value $1.
>
> assign : variable ASSIGN expression
> {
> $$->term.oper = op_assign;
>
> This is also fixed by stating the default action.
>
> Surely this is a bug (?).
Actually, I prefer to leave this as is, instead of promoting
the fact that $$ = $1 is run beforehand. This is not true
for all the configurations (where the warning is right),
so I still prefer pushing the users towards explicitly
perform their $$ = $1 themselves.
Besides, you are not supposed to know that $$ = $1 is always
run before. The documentation should only state that if
no action at all is provided, then this action defaults to
{ $$ = $1; }.
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