Re: Error handling in a parser (return value or setjmp)

From	"Morten W. Petersen" <morphex@gmail.com>
Newsgroups	comp.lang.c
Subject	Re: Error handling in a parser (return value or setjmp)
Date	2015-10-13 18:14 +0200
Organization	Aioe.org NNTP Server
Message-ID	<mvjake$fm3$1@speranza.aioe.org> (permalink)
References	<mvhqgq$28c$1@speranza.aioe.org> <87mvvmdihg.fsf@bsb.me.uk> <dbfb2a3c-67b7-42de-aeff-a87742edbcf4@googlegroups.com>

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On 13.10.2015 17:26, supercat@casperkitty.com wrote:
> On Tuesday, October 13, 2015 at 8:08:06 AM UTC-5, Ben Bacarisse wrote:
>> setjmp is not a good fit for a utility library (I'm guessing that's what
>> you are writing because you said that the parse_file function should
>> probably be a test case).
>>
>> setjmp is just about usable if you control both locations -- all the
>> jump sources and destinations.  Jumping out of a library is fraught with
>> problems.
>
> There would be times it could be reasonable in a library if there is a
> defined means for attaching and detaching error-escape handlers (code
> which needs to attach a handler should save a pointer to the old one and
> create a new one; if the routine will exit normally, it should restore
> the old pointer and return.  If the attached error handler gets tripped,
> it should restore the old pointer and then jump to the old jmp_buff.
>
> What's important is that a library function should only jump around user
> code in cases where that behavior is a very clearly documented part of its
> functionality.

Is it possible to look back up in the call stack, to search for a given
point and restore to that?

It doesn't matter if it is expensive to do so, as the parser is for fast
reading and not validation / feedback.

-Morten

Thread

Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 04:33 +0200
  Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-13 15:54 +1300
    Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 05:07 +0200
  Re: Error handling in a parser (return value or setjmp) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-13 14:07 +0100
    Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 16:17 +0200
    Re: Error handling in a parser (return value or setjmp) supercat@casperkitty.com - 2015-10-13 08:26 -0700
      Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 18:14 +0200
        Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-14 07:46 +1300
          Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 22:06 +0200
            Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-14 10:32 +1300
              Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 23:47 +0200
                Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-14 11:02 +1300
                Re: Error handling in a parser (return value or setjmp) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-14 18:32 +0000
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-15 12:28 +0200
                Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-16 07:47 +1300
            Re: Error handling in a parser (return value or setjmp) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-13 21:39 +0000
              Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 23:49 +0200
                Re: Error handling in a parser (return value or setjmp) supercat@casperkitty.com - 2015-10-13 15:03 -0700
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 01:16 +0200
                Re: Error handling in a parser (return value or setjmp) Geoff <geoff@invalid.invalid> - 2015-10-13 16:46 -0700
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 02:13 +0200
                Re: Error handling in a parser (return value or setjmp) Geoff <geoff@invalid.invalid> - 2015-10-13 19:10 -0700
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 04:27 +0200
                Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-14 16:05 +1300
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 05:18 +0200
                Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-14 16:31 +1300
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 05:44 +0200
                Re: Error handling in a parser (return value or setjmp) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-15 12:06 +0000
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-15 16:08 +0200
                Re: Error handling in a parser (return value or setjmp) supercat@casperkitty.com - 2015-10-14 00:36 -0700
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-15 12:32 +0200
                Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-14 11:06 +1300
                Re: Error handling in a parser (return value or setjmp) David Brown <david.brown@hesbynett.no> - 2015-10-14 00:10 +0200
                Re: Error handling in a parser (return value or setjmp) James Kuyper <jameskuyper@verizon.net> - 2015-10-13 19:08 -0400
              Re: Error handling in a parser (return value or setjmp) raltbos@xs4all.nl (Richard Bos) - 2015-10-14 11:37 +0000
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-15 12:34 +0200
                Re: Error handling in a parser (return value or setjmp) Ian Collins <ian-news@hotmail.com> - 2015-10-16 07:56 +1300
                Re: Error handling in a parser (return value or setjmp) "Morten W. Petersen" <morphex@gmail.com> - 2015-10-16 05:45 +0200
            Re: Error handling in a parser (return value or setjmp) James Kuyper <jameskuyper@verizon.net> - 2015-10-13 18:53 -0400

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