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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: gcc needs a curly bracket matching/counting function
Date: Tue, 20 Dec 2016 12:16:38 -0800
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BartC <bc@freeuk.com> writes:
> On 20/12/2016 18:52, DFS wrote:
>> On 12/20/2016 12:04 PM, Ben Bacarisse wrote:
>>> #define OPEN {
>>>
>>> int main(void) OPEN }
>>>
>>> <snip>
>>
>> This one's easy: delete or ignore the #define line and replace ' OPEN '
>> with an opening curly bracket every time it's found.  When I say delete
>> I don't mean alter the source of course.
>
> It's a bit harder than that. OPEN could result from expanding another macro.
>
> Or there could be 100 macros all defined as {, or that include { in 
> their definition.
>
> You also now have to scan and look up all identifiers, as well as having 
> to actually deal with #define and #undef.
>
> But OPEN could also be defined inside an #include file. Or is part of a 
> conditional block so that it might be defined as { or } or anything else 
> according to some compiler option.
>
> So you can't deal with it 100% without implementing a full 
> pre-processor, and even that might depend on how a compiler is invoked.

Yes, but dealing with it 99% is probably good enough.

If the code doesn't use macros, digraphs, or trigraphs to hide braces,
existing tools can be used to find any missing braces.  If it does, I
probably don't care about fixing it.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"