From patchwork Thu Dec 5 15:33:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 11274973 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5C0EE1805 for ; Thu, 5 Dec 2019 15:34:29 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4224A24651 for ; Thu, 5 Dec 2019 15:34:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4224A24651 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ict83-0007Yo-94; Thu, 05 Dec 2019 15:33:19 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ict81-0007Yi-NN for xen-devel@lists.xenproject.org; Thu, 05 Dec 2019 15:33:17 +0000 X-Inumbo-ID: 8e52cab4-1774-11ea-822b-12813bfff9fa Received: from mx1.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 8e52cab4-1774-11ea-822b-12813bfff9fa; Thu, 05 Dec 2019 15:33:16 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6B118B2DB; Thu, 5 Dec 2019 15:33:15 +0000 (UTC) To: "xen-devel@lists.xenproject.org" From: Jan Beulich Message-ID: Date: Thu, 5 Dec 2019 16:33:29 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 Content-Language: en-US Subject: [Xen-devel] [PATCH] cmdline: treat hyphens and underscores the same X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Konrad Wilk , George Dunlap , Andrew Cooper , Ian Jackson Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" In order to avoid permanently having to ask that no new command line options using underscores be introduced (albeit I'm likely to still make remarks), and in order to also allow extending the use of hyphens to pre-existing ones, introduce custom comparison functions treating both characters as matching. Signed-off-by: Jan Beulich --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -72,6 +72,11 @@ Some options take a comma separated list Some parameters act as combinations of the above, most commonly a mix of Boolean and String. These are noted in the relevant sections. +### Spelling + +Parameter names may include hyphens or underscores. These are +generally being treated as matching one another by the parsing logic. + ## Parameter details ### acpi --- a/xen/common/kernel.c +++ b/xen/common/kernel.c @@ -23,6 +23,49 @@ enum system_state system_state = SYS_STA xen_commandline_t saved_cmdline; static const char __initconst opt_builtin_cmdline[] = CONFIG_CMDLINE; +static int cdiff(unsigned char c1, unsigned char c2) +{ + int res = c1 - c2; + + if ( res && (c1 ^ c2) == ('-' ^ '_') && + (c1 == '-' || c1 == '_') ) + res = 0; + + return res; +} + +/* + * String comparison functions mostly matching strcmp() / strncmp(), + * except that they treat '-' and '_' as matching one another. + */ +static int _strcmp(const char *s1, const char *s2) +{ + int res; + + for ( ; ; ++s1, ++s2 ) + { + res = cdiff(*s1, *s2); + if ( res || !*s1 ) + break; + } + + return res; +} + +static int _strncmp(const char *s1, const char *s2, size_t n) +{ + int res = 0; + + for ( ; n--; ++s1, ++s2 ) + { + res = cdiff(*s1, *s2); + if ( res || !*s1 ) + break; + } + + return res; +} + static int assign_integer_param(const struct kernel_param *param, uint64_t val) { switch ( param->len ) @@ -94,7 +137,7 @@ static int parse_params(const char *cmdl /* Boolean parameters can be inverted with 'no-' prefix. */ key = optkey; - bool_assert = !!strncmp("no-", optkey, 3); + bool_assert = !!_strncmp("no-", optkey, 3); if ( !bool_assert ) optkey += 3; @@ -105,11 +148,11 @@ static int parse_params(const char *cmdl int rctmp; const char *s; - if ( strcmp(param->name, optkey) ) + if ( _strcmp(param->name, optkey) ) { if ( param->type == OPT_CUSTOM && q && strlen(param->name) == q + 1 - opt && - !strncmp(param->name, opt, q + 1 - opt) ) + !_strncmp(param->name, opt, q + 1 - opt) ) { found = true; optval[-1] = '='; @@ -275,7 +318,7 @@ int parse_bool(const char *s, const char int parse_boolean(const char *name, const char *s, const char *e) { size_t slen, nlen; - int val = !!strncmp(s, "no-", 3); + int val = !!_strncmp(s, "no-", 3); if ( !val ) s += 3; @@ -284,7 +327,7 @@ int parse_boolean(const char *name, cons nlen = strlen(name); /* Does s now start with name? */ - if ( slen < nlen || strncmp(s, name, nlen) ) + if ( slen < nlen || _strncmp(s, name, nlen) ) return -1; /* Exact, unadorned name? Result depends on the 'no-' prefix. */ @@ -304,7 +347,7 @@ int cmdline_strcmp(const char *frag, con for ( ; ; frag++, name++ ) { unsigned char f = *frag, n = *name; - int res = f - n; + int res = cdiff(f, n); if ( res || n == '\0' ) {