From owner-svn-src-head@freebsd.org Fri Dec 2 16:28:20 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0FCD5C62A28; Fri, 2 Dec 2016 16:28:20 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D3A4112EF; Fri, 2 Dec 2016 16:28:19 +0000 (UTC) (envelope-from pfg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id uB2GSJ1G004893; Fri, 2 Dec 2016 16:28:19 GMT (envelope-from pfg@FreeBSD.org) Received: (from pfg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id uB2GSJVP004892; Fri, 2 Dec 2016 16:28:19 GMT (envelope-from pfg@FreeBSD.org) Message-Id: <201612021628.uB2GSJVP004892@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: pfg set sender to pfg@FreeBSD.org using -f From: "Pedro F. Giffuni" Date: Fri, 2 Dec 2016 16:28:19 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r309415 - head/usr.bin/indent X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Dec 2016 16:28:20 -0000 Author: pfg Date: Fri Dec 2 16:28:18 2016 New Revision: 309415 URL: https://svnweb.freebsd.org/changeset/base/309415 Log: indent(1): Optimize parser stack usage. When special else-if processing is enabled (-ei), we can assume "else if" and "if" to be equivalent for indentation purposes. This reduction saves a lot of stack space in case of a long "if-else-if ... else-if" sequence; with this change, Postgres/src/bin/psql/tab-complete.c as of 9.6beta3 requires minimum of the stack length to be 31 instead of 444. Submitted by: Piotr Sephaniak Modified: head/usr.bin/indent/parse.c Modified: head/usr.bin/indent/parse.c ============================================================================== --- head/usr.bin/indent/parse.c Fri Dec 2 15:38:34 2016 (r309414) +++ head/usr.bin/indent/parse.c Fri Dec 2 16:28:18 2016 (r309415) @@ -94,7 +94,13 @@ parse(int tk) /* tk: the code for the co case ifstmt: /* scanned if (...) */ if (ps.p_stack[ps.tos] == elsehead && ps.else_if) /* "else if ..." */ - ps.i_l_follow = ps.il[ps.tos]; + /* + * Note that the stack pointer here is decremented, effectively + * reducing "else if" to "if". This saves a lot of stack space + * in case of a long "if-else-if ... else-if" sequence. + */ + ps.i_l_follow = ps.il[ps.tos--]; + /* the rest is the same as for dolit and forstmt */ case dolit: /* 'do' */ case forstmt: /* for (...) */