Re: Horrible compiletimes and memory usage while compiling a parser with X3

On 11/13/2016 02:53 PM, Larry Evans wrote:
> On 11/13/2016 07:50 AM, Larry Evans wrote:
>> On 11/07/2016 02:44 AM, Peter Gerell wrote:
>>> On 07/11/2016 12:38 PM , Joel de Guzman wrote:
>>>> On 07/11/2016 1:26 AM, Mikael Asplund wrote:
>>>>> This is the reason we're still on 1.60 (with a small
>>>>> const-patch from 1.61), since later version have link problems which are just too hard
>>>>> to debug.
>>>
>>>> It would be great if you post a test file that exhibits this problem you mention.
>>>> This linking problem doesn't look good and must be fixed.
>>>
>>> Hi Joel.
>>> This is the problem Mikael is referring to.
>>> http://melpon.org/wandbox/permlink/X8Awj4wIZ2JqMWIw
>>>
>>> If KEEP_CHAR is defined the code builds with both boost 1.60 and 1.61.
>>> Without KEEP_CHAR it fails with 1.61.
>>>
>>> The following commit introduced the problem.
>>> https://github.com/boostorg/spirit/commit/a8e391bd99dddb3f9ece84bdb1bb9236b0a37cf7
>>>
>>> The problem seems to be that the attribute types are short-circuited for sequences of one
>>> even though we explicitly request a specific binding using FUSION_DEFINE_FOR_STRUCT(ast::Start, count);
>> [snip]
>>
>> More specifically, the change on line 178 causes the
>> problem.
> [snip]
>> Why not revert the change on detail/sequence.hpp:178 to
>> solve the problem?
>
> Or instead of:
>
> https://github.com/boostorg/spirit/blob/boost-1.61.0/include/boost/spirit/home/x3/operator/detail/sequence.hpp#L178
>
> why not make the bool value dependent on whether R is *not* a rule?
> A similar change would be made to:
>
> https://github.com/boostorg/spirit/blob/boost-1.61.0/include/boost/spirit/home/x3/operator/detail/sequence.hpp#L198
>
> WARNING: not tested.
>
OR, try the spirit rule.hpp patches here:

https://github.com/cppljevans/spirit/blob/ExagonLinkingError/include/boost/spirit/home/x3/nonterminal/rule.hpp#L129

When run with the modification of your problem code here:

https://github.com/cppljevans/boost_1_61_problem

there's no link error.  Fortunately, this change also solves
the problem which Exagon was having:

https://sourceforge.net/p/spirit/mailman/message/35502917/

HTH.

-regards,
Larry




------------------------------------------------------------------------------