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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id D5F2E3858CDA for ; Fri, 26 Aug 2022 08:31:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D5F2E3858CDA 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=1661502699; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type; bh=phzxHR5kRn1CCeO1UJgpRawiN5rtGnRbE8Ff0H9o/JY=; b=PKKvzS7bL62MXmPFKqYUEC2iRlumJSJFAsriru3U3gtrFYIwpLuqhoIQfydqfuI3aMQVkI Ig5vQJnftczxYOzssoTM8mhpqkzVxeDD+793ltXMOpWDkJDBsSbJ6CMUtBd5nFDvbaliCz /qff7abVUZn4nFcCjngqEvttHFHk2Nc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-382-dYkRbjYUOly3NvzEYm_Vcw-1; Fri, 26 Aug 2022 04:31:38 -0400 X-MC-Unique: dYkRbjYUOly3NvzEYm_Vcw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E93B91C04B4B for ; Fri, 26 Aug 2022 08:31:37 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.82]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 645F82026D64 for ; Fri, 26 Aug 2022 08:31:37 +0000 (UTC) From: Florian Weimer To: libc-alpha@sourceware.org Subject: Calling __cxa_thread_atexit_impl directly, from C code Date: Fri, 26 Aug 2022 10:31:35 +0200 Message-ID: <87lerbtnh4.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-5.2 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE 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: Do we support calling __cxa_thread_atexit_impl directly? The function is not documented, nor is it declared in any installed header. I think the answer is yes, because we support different C++ implementations, and they have to call __cxa_thread_atexit_impl for thread-local destructors, either directly or through a wrapper (__cxa_thread_atexit for libstdc++, as proposed for the Itanium C++ ABI). There's interest in this because it's much easier to use than pthread_key_create if you have to avoid linking against libpthread and you target glibc releases between 2.18 and 2.33 (although it is possible to use weak symbols, as in the libstdc++ implementation in libstdc++-v3/libsupc++/atexit_thread.cc). Thanks, Florian