[fpc-pascal]Extension of macros exceeds a depth of 16

[Olle Raab]

04-08-04 13.39, skrev Olle Raab följande:

> 04-07-28 21.42, skrev Alan Mead följande:
> 
>> As a I mentined earlier today in a different thread, I have upgraded
>> to 1.9.4 and I appreciate the greater checking.
>> 
>> Most of the new warnings I get are clear but one of my units now
>> reports "Extension of macros exceeds a depth of 16".  What does this
> ^^^^^^^^^^
> Actually I think the warning message is wrong..
> 
> It should imo be "Expanding". I'll fix this.
> 
>> warning mean and what is the rammification of ignoring it?
>> 
>> The line number where it reports the warning is an {$if def ...} and
>> I would assume the warning had something to do with nesting compiler
>> conditionals... but that's not the case (unless the parser is really
>> getting lost... but since the code operates, I cannot imagne that
>> this is happening..).  This conditional should be at the "top
>> level"--it is not nested under anything.
> 
> It the recursive macro substitution which exceeds a depth of 16.
> 
> This is probably due to a circular definition of a macro, e g
> 
> {$DEFINE X = X}
> 
> So that X is replaced by X, which is replaced by X etc. This is probably not
> what you want.
> 
> After 16 replacements the recursion is stoped, thats what it is warned
> about.

I found that there really was a bug here.

With 

{$DEFINE X}

{$IF X = 1}

etc..

You get the above error message, just because X does not have any value.
 (it then erroneously made a recurson). This is now fixed.

On the other hand, the above snippet is actually worng, beacause X does not
hae any value, and should not be allowed in an expression.

I will add error checking for this.

Olle