From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=unavailable autolearn_force=no version=3.4.2 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id CBDBE1F4B4 for ; Mon, 11 Jan 2021 12:36:54 +0000 (UTC) Received: from localhost ([::1]:47140 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kywRJ-0004TP-PO for normalperson@yhbt.net; Mon, 11 Jan 2021 07:36:53 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:32876) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kywMd-0002Hc-Ro for bug-gnulib@gnu.org; Mon, 11 Jan 2021 07:32:04 -0500 Received: from mail-qk1-x734.google.com ([2607:f8b0:4864:20::734]:46082) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kywMV-0006mg-P8 for bug-gnulib@gnu.org; Mon, 11 Jan 2021 07:32:03 -0500 Received: by mail-qk1-x734.google.com with SMTP id d14so14325897qkc.13 for ; Mon, 11 Jan 2021 04:31:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=PQ39K6ddahPl6as66BL/d/lts5/sbsLVisxlymhisGE=; b=SzlBi7po9PNe8D9V2UowxZjndSgA8M1IN1vyB8txU+zTepfOADwe7f/D6U+pqrjnwe cajPIavfDoWAtSms1JCmFlQnWrRPnlJ/h+5h0dh+2u9mCgeHV7staxMDfAHut0qRMAls 2r5hTTIH2DOnWzQdVTnQhK5UI+G6L64CXn2UloITMlqqFxvYeA3Z0Yz9k9iaktsC80Ow fAkAZg2k1rCPITzhSY3TgYQBT7cD2hrQ14ObUWB37KtCZ3jvqogEFsHB3sgBZg1/VTMv cH+zw34cTuKD3ksXUGsAaPNYdcIptEHeB8KJDFKMQzgAKwZfLWhUi/Rz/4I+4z1/32nI 17yw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=PQ39K6ddahPl6as66BL/d/lts5/sbsLVisxlymhisGE=; b=MXoqJTzJnMMz8C5A+f2TV8yj8iQgXeZHfpFRYab3DQdXzZezfJb4R9weF1rFmwdVrq aass3issKMh2zfhlY9deg1wrNXeDLo/OS3lD0zSvmkasTATq68OC0IGXhHVmgsbcB7p7 hdOafjup9sopvubCVoxa5hKlzJPS1ELN2giRxpMnrR8lvymSwiVQritkiQphBFcYCIYT B74VfAS67y9Z67piiuSEqmemloDP6H3zuSzc6yvWHXMb6cco9WXYvv81Xk3lWYb3/ZrK vHwfZKsexykF4YY5CoO7lBS7dd9E/k+TUfAPw755Q1hkdIFyPKO6tM+qZa45WElKZpn2 ryKw== X-Gm-Message-State: AOAM5311rfeD503q51ycvp4yczyUo6uhImOoGUjOKI1Kt/+dSyiRlZC3 6i7EmurZ3V/d5CNzjp0XK9AcYN+60US06w== X-Google-Smtp-Source: ABdhPJx8aSqY7uQ7ak/wMjGHtvEk6MLt0cDlrs5f1jVhhnoC48aVH/zSapr5dlwqGSAUJa2BeIhtJw== X-Received: by 2002:a05:620a:39c:: with SMTP id q28mr15499206qkm.276.1610368314208; Mon, 11 Jan 2021 04:31:54 -0800 (PST) Received: from [192.168.1.4] ([177.194.48.209]) by smtp.googlemail.com with ESMTPSA id 74sm8125372qko.59.2021.01.11.04.31.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Jan 2021 04:31:53 -0800 (PST) Subject: Re: [PATCH 2/3] posix: Remove alloca usage on regex build_trtable To: Paul Eggert References: <20210106181707.1738066-1-adhemerval.zanella@linaro.org> <20210106181707.1738066-2-adhemerval.zanella@linaro.org> <831a8e3b-7a4a-0c9a-418e-0656fc137765@cs.ucla.edu> From: Adhemerval Zanella Autocrypt: addr=adhemerval.zanella@linaro.org; prefer-encrypt=mutual; keydata= mQINBFcVGkoBEADiQU2x/cBBmAVf5C2d1xgz6zCnlCefbqaflUBw4hB/bEME40QsrVzWZ5Nq 8kxkEczZzAOKkkvv4pRVLlLn/zDtFXhlcvQRJ3yFMGqzBjofucOrmdYkOGo0uCaoJKPT186L NWp53SACXguFJpnw4ODI64ziInzXQs/rUJqrFoVIlrPDmNv/LUv1OVPKz20ETjgfpg8MNwG6 iMizMefCl+RbtXbIEZ3TE/IaDT/jcOirjv96lBKrc/pAL0h/O71Kwbbp43fimW80GhjiaN2y WGByepnkAVP7FyNarhdDpJhoDmUk9yfwNuIuESaCQtfd3vgKKuo6grcKZ8bHy7IXX1XJj2X/ BgRVhVgMHAnDPFIkXtP+SiarkUaLjGzCz7XkUn4XAGDskBNfbizFqYUQCaL2FdbW3DeZqNIa nSzKAZK7Dm9+0VVSRZXP89w71Y7JUV56xL/PlOE+YKKFdEw+gQjQi0e+DZILAtFjJLoCrkEX w4LluMhYX/X8XP6/C3xW0yOZhvHYyn72sV4yJ1uyc/qz3OY32CRy+bwPzAMAkhdwcORA3JPb kPTlimhQqVgvca8m+MQ/JFZ6D+K7QPyvEv7bQ7M+IzFmTkOCwCJ3xqOD6GjX3aphk8Sr0dq3 4Awlf5xFDAG8dn8Uuutb7naGBd/fEv6t8dfkNyzj6yvc4jpVxwARAQABtElBZGhlbWVydmFs IFphbmVsbGEgTmV0dG8gKExpbmFybyBWUE4gS2V5KSA8YWRoZW1lcnZhbC56YW5lbGxhQGxp bmFyby5vcmc+iQI3BBMBCAAhBQJXFRpKAhsDBQsJCAcDBRUKCQgLBRYCAwEAAh4BAheAAAoJ EKqx7BSnlIjv0e8P/1YOYoNkvJ+AJcNUaM5a2SA9oAKjSJ/M/EN4Id5Ow41ZJS4lUA0apSXW NjQg3VeVc2RiHab2LIB4MxdJhaWTuzfLkYnBeoy4u6njYcaoSwf3g9dSsvsl3mhtuzm6aXFH /Qsauav77enJh99tI4T+58rp0EuLhDsQbnBic/ukYNv7sQV8dy9KxA54yLnYUFqH6pfH8Lly sTVAMyi5Fg5O5/hVV+Z0Kpr+ZocC1YFJkTsNLAW5EIYSP9ftniqaVsim7MNmodv/zqK0IyDB GLLH1kjhvb5+6ySGlWbMTomt/or/uvMgulz0bRS+LUyOmlfXDdT+t38VPKBBVwFMarNuREU2 69M3a3jdTfScboDd2ck1u7l+QbaGoHZQ8ZNUrzgObltjohiIsazqkgYDQzXIMrD9H19E+8fw kCNUlXxjEgH/Kg8DlpoYJXSJCX0fjMWfXywL6ZXc2xyG/hbl5hvsLNmqDpLpc1CfKcA0BkK+ k8R57fr91mTCppSwwKJYO9T+8J+o4ho/CJnK/jBy1pWKMYJPvvrpdBCWq3MfzVpXYdahRKHI ypk8m4QlRlbOXWJ3TDd/SKNfSSrWgwRSg7XCjSlR7PNzNFXTULLB34sZhjrN6Q8NQZsZnMNs TX8nlGOVrKolnQPjKCLwCyu8PhllU8OwbSMKskcD1PSkG6h3r0AquQINBFcVGkoBEACgAdbR Ck+fsfOVwT8zowMiL3l9a2DP3Eeak23ifdZG+8Avb/SImpv0UMSbRfnw/N81IWwlbjkjbGTu oT37iZHLRwYUFmA8fZX0wNDNKQUUTjN6XalJmvhdz9l71H3WnE0wneEM5ahu5V1L1utUWTyh VUwzX1lwJeV3vyrNgI1kYOaeuNVvq7npNR6t6XxEpqPsNc6O77I12XELic2+36YibyqlTJIQ V1SZEbIy26AbC2zH9WqaKyGyQnr/IPbTJ2Lv0dM3RaXoVf+CeK7gB2B+w1hZummD21c1Laua +VIMPCUQ+EM8W9EtX+0iJXxI+wsztLT6vltQcm+5Q7tY+HFUucizJkAOAz98YFucwKefbkTp eKvCfCwiM1bGatZEFFKIlvJ2QNMQNiUrqJBlW9nZp/k7pbG3oStOjvawD9ZbP9e0fnlWJIsj 6c7pX354Yi7kxIk/6gREidHLLqEb/otuwt1aoMPg97iUgDV5mlNef77lWE8vxmlY0FBWIXuZ yv0XYxf1WF6dRizwFFbxvUZzIJp3spAao7jLsQj1DbD2s5+S1BW09A0mI/1DjB6EhNN+4bDB SJCOv/ReK3tFJXuj/HbyDrOdoMt8aIFbe7YFLEExHpSk+HgN05Lg5TyTro8oW7TSMTk+8a5M kzaH4UGXTTBDP/g5cfL3RFPl79ubXwARAQABiQIfBBgBCAAJBQJXFRpKAhsMAAoJEKqx7BSn lIjvI/8P/jg0jl4Tbvg3B5kT6PxJOXHYu9OoyaHLcay6Cd+ZrOd1VQQCbOcgLFbf4Yr+rE9l mYsY67AUgq2QKmVVbn9pjvGsEaz8UmfDnz5epUhDxC6yRRvY4hreMXZhPZ1pbMa6A0a/WOSt AgFj5V6Z4dXGTM/lNManr0HjXxbUYv2WfbNt3/07Db9T+GZkpUotC6iknsTA4rJi6u2ls0W9 1UIvW4o01vb4nZRCj4rni0g6eWoQCGoVDk/xFfy7ZliR5B+3Z3EWRJcQskip/QAHjbLa3pml xAZ484fVxgeESOoaeC9TiBIp0NfH8akWOI0HpBCiBD5xaCTvR7ujUWMvhsX2n881r/hNlR9g fcE6q00qHSPAEgGr1bnFv74/1vbKtjeXLCcRKk3Ulw0bY1OoDxWQr86T2fZGJ/HIZuVVBf3+ gaYJF92GXFynHnea14nFFuFgOni0Mi1zDxYH/8yGGBXvo14KWd8JOW0NJPaCDFJkdS5hu0VY 7vJwKcyHJGxsCLU+Et0mryX8qZwqibJIzu7kUJQdQDljbRPDFd/xmGUFCQiQAncSilYOcxNU EMVCXPAQTteqkvA+gNqSaK1NM9tY0eQ4iJpo+aoX8HAcn4sZzt2pfUB9vQMTBJ2d4+m/qO6+ cFTAceXmIoFsN8+gFN3i8Is3u12u8xGudcBPvpoy4OoG Message-ID: <1546c8d0-fd22-0e10-8f0d-2b6f1791f1c1@linaro.org> Date: Mon, 11 Jan 2021 09:31:51 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <831a8e3b-7a4a-0c9a-418e-0656fc137765@cs.ucla.edu> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::734; envelope-from=adhemerval.zanella@linaro.org; helo=mail-qk1-x734.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: bug-gnulib@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Gnulib discussion list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: bug-gnulib@gnu.org, libc-alpha@sourceware.org Errors-To: bug-gnulib-bounces+normalperson=yhbt.net@gnu.org Sender: "bug-gnulib" On 08/01/2021 19:30, Paul Eggert wrote: > On 1/6/21 10:17 AM, Adhemerval Zanella wrote: >> __libc_use_alloca/alloca is replaced with malloc regardless. > > These allocations are so small that they should be put on the stack instead of using malloc. I did that in Gnulib by installing the attached patch. The idea is that the resulting regexec.c file should be copyable unchanged into glibc. > > From a Gnulib point of view this code uses a 20 KiB frame (on a 64-bit host) which goes past the usual 4032-byte limit for stack frames, but I think we can stretch the point here.  In glibc the limit is 64 KiB so there's no problem. Right, I think we can maybe use scratch_buffer for these or even a dynamic array with a more proper initial size as an improvement.