Path: csiph.com!4.us.feeder.erje.net!feeder.erje.net!feeder.usenetexpress.com!feeder-in1.iad1.usenetexpress.com!border1.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Philipp Klaus Krause Newsgroups: comp.compilers Subject: Re: Why do some versions of bison require {} here? Date: Thu, 3 Jan 2019 09:15:25 +0100 Organization: solani.org Lines: 16 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <19-01-003@comp.compilers> References: <19-01-001@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="16991"; mail-complaints-to="abuse@iecc.com" Keywords: yacc Posted-Date: 03 Jan 2019 20:15:04 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Content-Language: en-US Xref: csiph.com comp.compilers:2145 Am 01.01.19 um 10:55 schrieb Philipp Klaus Krause: > [Adding the empty action forces bison to reduce the rule rather than just > shifting and saving state for later. I couldn't guess why that would matter > in this case. Are there precedence rules? With your change does the grammar compile > cleanly or does it have conflicts? -John] > Well, for me (but I don't see the problem without the {} on my system - GNU bison 3.2.2 on Debian GNU/Linux), both with and without {}, when using LANG=C bison -W -y -d SDCC.y I get 7 warning about "empty rule without %empty", but no other warnings. The people reporting issues seem to be using GNU bison on Microsoft Windows. Philipp