From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 43FC03858D37 for ; Mon, 21 Feb 2022 11:20:52 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 43FC03858D37 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645442451; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=RGVIWqpxYuUAk9cc5ABf3cU+tKFkKMEvNIfDY5aLvFU=; b=gSoS69QCu9m6lk7Sy8IAyBjkLGMXQsuKXGVEI6TFT7e8QAYt68gorthOnXratxL+OiXH+b 5X/HpyBc6cHk3pHY0iZQShcit1vqoJ16O/p4TD9XpGOh+jCn8VcqLlPLXC9UhOLYfyCGqH IEm/FT0XzZiss7QiSVyqUCuaP+em2d8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-399-WsRCbZRRPRWGBtJqnfOElw-1; Mon, 21 Feb 2022 06:20:48 -0500 X-MC-Unique: WsRCbZRRPRWGBtJqnfOElw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9C078802B60; Mon, 21 Feb 2022 11:20:47 +0000 (UTC) Received: from calimero.vinschen.de (unknown [10.36.112.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6B8D566E27; Mon, 21 Feb 2022 11:20:47 +0000 (UTC) Received: by calimero.vinschen.de (Postfix, from userid 500) id E0CF2A80D35; Mon, 21 Feb 2022 12:20:45 +0100 (CET) Date: Mon, 21 Feb 2022 12:20:45 +0100 From: Corinna Vinschen To: Mike Frysinger Cc: newlib@sourceware.org Subject: Re: [PATCH v2] newlib: libm: merge build up a directory Message-ID: Reply-To: newlib@sourceware.org Mail-Followup-To: Mike Frysinger , newlib@sourceware.org References: <20220212203450.19650-1-vapier@gentoo.org> <20220217044256.5483-1-vapier@gentoo.org> MIME-Version: 1.0 In-Reply-To: <20220217044256.5483-1-vapier@gentoo.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vinschen@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Spam-Status: No, score=-6.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: newlib@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Newlib mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Feb 2022 11:20:53 -0000 Hi Mike, On Feb 16 23:42, Mike Frysinger wrote: > Convert all the libm/ subdir makes into the top-level Makefile. This > allows us to build all of libm from the top Makefile without using any > recursive make calls. This is faster and avoids the funky lib.a logic > where we unpack subdir archives to repack into a single libm.a. The > machine override logic is maintained though by way of Makefile include > ordering, and source file accumulation in libm_a_SOURCES. > > One thing to note is that this will require GNU Make because of: > libm_a_CFLAGS = ... $(libm_a_CFLAGS_$(subst /,_,$(@D))) > This was the only way I could find to supporting per-dir compiler > settings, and I couldn't find a POSIX compatible way of transforming > the variable content. I don't think this is a big deal as other > Makefiles in the tree are using GNU Make-specific syntax, but I call > this out as it's the only one so far in the new automake code that > I've been writing. > > Automake doesn't provide precise control over the output object names > (by design). This is fine by default as we get consistent names in all > the subdirs: libm_a-.o. But this relies on using the same set > of compiler flags for all objects. We currently compile libm/common/ > with different optimizations than the rest. > > If we want to compile objects differently, we can create an intermediate > archive with the subset of objects with unique flags, and then add those > objects to the main archive. But Automake will use a different prefix > for the objects, and thus we can't rely on ordering to override. > > But if we leverage $@, we can turn Automake's CFLAGS into a multiplex > on a per-dir (and even per-file if we wanted) basis. Unfortunately, > since $@ contains /, Automake complains it's an invalid name. While > GNU Make supports this, it's a POSIX extension, so Automake flags it. > Using $(subst) avoids the Automake warning to get a POSIX compliant > name, albeit with a GNU Make extension. > --- > v2 > - rebased onto latest tree > - fixed a parallel build issue with generated newlib headers & libm objects This patch breaks Cygwin. Unfortunately I didn't try to build myself, but only inspected the patch, so I didn't realize the problem. First of all, Cygwin takes libm.a from newlib/libm/, not from newlib. This is easily fixable. However, even after fixing this, we get a link stage error for *all* fenv functions: ld: x86_64-pc-cygwin/newlib/libm.a(libm_a-fenv.o): in function `fegetenv': newlib/libm/machine/x86_64/../shared_x86/fenv.c:160: multiple definition of `fegetenv'; x86_64-pc-cygwin/newlib/libm.a(libm_a-fegetenv.o): newlib/libm/fenv/fegetenv.c:65: first defined here For some reason, libm.a contains both definitions of the fenv functions, the x86_64 definitions from newlib/libm/machine/shared_x86, as well as the fallback definitions from newlib/libm/fenv. Can you please take a look? Thanks, Corinna