From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-xb2d.google.com (mail-yb1-xb2d.google.com [IPv6:2607:f8b0:4864:20::b2d]) by sourceware.org (Postfix) with ESMTPS id 756153858D20 for ; Thu, 25 Apr 2024 15:33:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 756153858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 756153858D20 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2607:f8b0:4864:20::b2d ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1714059206; cv=none; b=KTbEjQVPodyejF3OR2/YbGUfgcgJfdwfJ5cr2AQ89TMz7OXKcYLM9DRErLH5J5H5CgrjE7oPxanfawXAqGWTDRSqLwclbTAPJDS9XJkMR4OVl4g1QZ64cDuWMwmV62xFZAjG4w3BA58INY3BjWJBIwU2WDwz1FTOlNQ+DpkVK04= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1714059206; c=relaxed/simple; bh=TAYocjlpFhpElZk/ds4amdyXIOwmbUnrReVJDxseAUI=; h=DKIM-Signature:MIME-Version:From:Date:Message-ID:Subject:To; b=Xr++4VQEHPXNAR+7Ax5333aQxkxybYkyR9UiERVh1QwY9IIuTZeSCUBosSJ6jtKlMtenyPXgPHltNHQqpsoFVkvgbuZ1XDCIyo7THhdaYU/cTreH2p/E7pOLzN9yCGfqF14HRDnEps+2TGvGxmg00xs4pGf9CwmO64quZrBtzQE= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-yb1-xb2d.google.com with SMTP id 3f1490d57ef6-dcc71031680so1196217276.2 for ; Thu, 25 Apr 2024 08:33:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1714059200; x=1714664000; darn=sourceware.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=DAA+xLLxfuiNnkGO5PF0+25BktAtsPqsI5CXwnWXYAs=; b=i4QkAqL1HtfCSgSljwQhE7SUUfKjZ+8MXXTPVzPSRFXqP8z3M5yzpfj0QtpcAB7Lde 3CAzLWpAfRWI3fE0Wh92FW3pRkvoNKyRlsxpyE/ZSRQZFmtuxu9r2Qg8qizgbvqXaWdO eauPwfPobs27zJiC2n9yYdhDMAt7URAnpHbqdOnhnHz95vbdBgWitgMgf/0TYwhSTKnp 9lx5XSe30sPhZtZCy5qEw8VatPHWshbIEufh4pibWrx0xjsiAP+mOhYqsU3Sfjy6PSG9 OIJ9KTWnV1OqCDuQMA3AGR0GOeWFnSwM5i/DhOvDDgmQYmXC/wxUwJNoeZbKSVLT8Bsc OyHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714059200; x=1714664000; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=DAA+xLLxfuiNnkGO5PF0+25BktAtsPqsI5CXwnWXYAs=; b=p8nrBnUIp19Uanzcxd/XAI/QJrHT6HyOzj+HzjTEsRiR6IqLYoV0YUfwFxxXfA0Ac7 bpLFZR+dhIphRzjNgdq9i5lZE9yd0xJpX3ECuqikMwecEtRhjGC7yx/LT3leEdYDkP+f C1duG3KMEILiFiVO8QBrWeK9QnJYtPlAv9qd+d5twCxSOeLTEOsdU6KyFLMRyMzzFJki 0iulK9bESHVvgC9kkGn/2+MsygSHeTXiR+OhHWJIjZ8vp3qQMtafkPZI3/KtreUcL9aK VrijhcWWn/tOrG7DFqQv0SwltAauHIU1VfD7iIlupdU7nWOF/5mJ6tmAuOfImpMq+aYR UPeQ== X-Gm-Message-State: AOJu0YwWmvz4q12J92xSI86BXC7lpPZkLAlDIc2WAKAUU2NZKJ/Ir7Mp Uh9/RmFEzL9gnKqZzGZz8R288W+kj3VHqT4NgBOK8pdpljN2LfbEIWhsRgbO2Y1Qx4bPMC15oTV MEYh5X1NFBc40uLQz2a7W39bugNqnCw== X-Google-Smtp-Source: AGHT+IGUQ6cIEiyKuEXKgdzmP9AkHJ0Bwp4LeXN4RPERM6BL6asVTbNU5vZTCWTRbS/3gJOK3gDe4RkSlrQYhHN2p9U= X-Received: by 2002:a25:ac49:0:b0:de5:1553:4351 with SMTP id r9-20020a25ac49000000b00de515534351mr6951404ybd.15.1714059199609; Thu, 25 Apr 2024 08:33:19 -0700 (PDT) MIME-Version: 1.0 References: <87edat7g1e.fsf@redhat.com> In-Reply-To: <87edat7g1e.fsf@redhat.com> From: "H.J. Lu" Date: Thu, 25 Apr 2024 08:32:43 -0700 Message-ID: Subject: Re: RFC: ld: Add --text-section-ordering-file (version 2) To: Nick Clifton Cc: binutils@sourceware.org, siddhesh@redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-3013.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, Apr 25, 2024 at 6:01=E2=80=AFAM Nick Clifton wro= te: > > Hi Guys, > > Attached is a patch to add a --section-ordering-file option to the BFD > linker. It is based upon H.J.'s original patch, but extended so that > it will work with multiple output sections. > > There are a couple of points that I feel I should highlight: > > * The option only works in conjunction with a modified linker script. > > In particular the script must have: "INCLUDE section-ordering-file" > statements in it, wherever it wants section ordering to be allowed. > This statement can appear multiple times in a linker script, > although it would not make sense to have it appear more than once in > any given output section. Here is an example: > > SECTIONS > { > .text : { > INCLUDE section-ordering-file > *(.text) > } > .data : { > INCLUDE section-ordering-file > *(.data) > } > } > > * H.J's original version allowed for linker script like > "filename(section)" syntax to be used to name sections, eg: > "*(.text.*)", as well as a simpler "section name regexp", eg > ".text.*", to be used. This version only supports the latter > format. > > In addition H.J.'s syntax allowed for abbreviated section names to > match. So ".t*t" would match any section starting with ".t" and > ending with "t" and would put it into the .text section. In this > version however the output section is selected based upon matching > the fixed part at the start of the pattern with the output section. > So ".t*t" would only work if the output section was called ".t". > > To help compensate for this, and to allow arbitrary input sections > to be mapped to specific output sections, the output section name > can be provided as if it were a filename. So .foo(.bar) would map > all sections called .bar to the output section .foo, but only if the > linker script has an output section called .foo, and only if that > output section declaration includes a INCLUDE section-ordering-file > statement. > > Perhaps an example will make things clearer. If the above linker > script is used and the section ordering file contains: > > # A comment - this will be ignored. > .text.hot .text.cold .text.warm > .data.big > .data(.bar) > .text.foo* > .ignore(.me) > > This is roughly equivalent to a linker script that looks like this: > > SECTIONS > { > .text : { > *(.text.hot) > *(.text.cold) > *(.text.warm) > *(.text.foo*) > *(.text) > } > .data : { > *(.data.big) > *(.bar) > *(.data) > } > } > > Note - the linker will not warn about entries in the section > ordering file that do not match an output section name. So in the > above example the ".ignore(.me)" entry will not generate a warning > about it not being used. > > Thoughts, comments, etc ? > Should it also handle .rodata, .bss and other data sections? --=20 H.J.