From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29146 invoked by alias); 13 Feb 2020 20:30:49 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 29122 invoked by uid 89); 13 Feb 2020 20:30:47 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-23.5 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,SPF_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mail.efficios.com Received: from mail.efficios.com (HELO mail.efficios.com) (167.114.26.124) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 13 Feb 2020 20:30:45 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 3F575261448 for ; Thu, 13 Feb 2020 15:30:44 -0500 (EST) Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id Txf9ulyMilPi; Thu, 13 Feb 2020 15:30:44 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id BA8A7261618; Thu, 13 Feb 2020 15:30:42 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com BA8A7261618 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1581625842; bh=b2U9/37rZayAuYxm7//WwNsgBxlTM38sw/XeFmWiaGM=; h=From:To:Date:Message-Id:MIME-Version; b=F8sltJo83iGccDBL3NmYUVZ4qlKPOSHrMKVvIYYHZvR/v+CgO62RqlaeinE/pRHhH jeamQ74P7ZYAakYLkYzoi5EyFsPn9xSzybLQj1C7mDIPCVNGwpeK8dr5xhIKzGvB5k hUYPrLQ+bZSViRAuHcRyOHATvO/PjBYT/gMgdJkjKnSqFyQu9IPyC6pmpiAAbzM0fv N87mM2rfmuSHkDqnmgaYU372MYMzURPszoHnCK8JSOfD92QbkhuQD2KhTWsxKcpSNC WEQihI5qEC3jCsOI28g4bs6vGfGiy22F5ZLLrC57FDRG4v4RK70h7sVmBfAT/hvMqd t2Ie/woiJTr4g== Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 0vhVlFqIWaIT; Thu, 13 Feb 2020 15:30:42 -0500 (EST) Received: from smarchi-efficios.internal.efficios.com (192-222-181-218.qc.cable.ebox.net [192.222.181.218]) by mail.efficios.com (Postfix) with ESMTPSA id 8D742261700; Thu, 13 Feb 2020 15:30:42 -0500 (EST) From: Simon Marchi To: gdb-patches@sourceware.org Cc: Simon Marchi Subject: [PATCH 3/5] gdb: allow duplicate enumerators in flag enums Date: Thu, 13 Feb 2020 20:30:00 -0000 Message-Id: <20200213203035.30157-3-simon.marchi@efficios.com> In-Reply-To: <20200213203035.30157-1-simon.marchi@efficios.com> References: <20200213203035.30157-1-simon.marchi@efficios.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SW-Source: 2020-02/txt/msg00533.txt.bz2 I have come across some uses cases where it would be desirable to treat an enum that has duplicate values as a "flag enum". For example, this one here [1]: enum membarrier_cmd { MEMBARRIER_CMD_QUERY =3D 0, MEMBARRIER_CMD_GLOBAL =3D (1 << 0= ), MEMBARRIER_CMD_GLOBAL_EXPEDITED =3D (1 << 1= ), MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED =3D (1 << 2= ), MEMBARRIER_CMD_PRIVATE_EXPEDITED =3D (1 << 3= ), MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED =3D (1 << 4= ), MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE =3D (1 << 5= ), MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE =3D (1 << 6= ), /* Alias for header backward compatibility. */ MEMBARRIER_CMD_SHARED =3D MEMBARRIER_CMD_GLOBAL, }; The last enumerator is kept for backwards compatibility. Without this patch, this enumeration wouldn't be considered a flag enum, because two enumerators collide. With this patch, it would be considered a flag enum, and the value 3 would be printed as: MEMBARRIER_CMD_GLOBAL | MEMBARRIER_CMD_GLOBAL_EXPEDITED Although if people prefer, we could display both MEMBARRIER_CMD_GLOBAL and MEMBARRIER_CMD_SHARED in the result. It wouldn't be wrong, and could perhaps be useful in case a bit may have multiple meanings (depending on some other bit value). [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree= /include/uapi/linux/membarrier.h?id=3D0bf999f9c5e74c7ecf9dafb527146601e5c84= 8b9#n125 --- gdb/dwarf2/read.c | 5 ----- gdb/testsuite/gdb.base/printcmds.c | 7 ++++--- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index b866cc2d5747..5c34667ef36d 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -15495,7 +15495,6 @@ update_enumeration_type_from_children (struct die_i= nfo *die, struct die_info *child_die; int unsigned_enum =3D 1; int flag_enum =3D 1; - ULONGEST mask =3D 0; =20 auto_obstack obstack; =20 @@ -15533,10 +15532,6 @@ update_enumeration_type_from_children (struct die_= info *die, =20 if (nbits !=3D 0 && nbits && nbits !=3D 1) flag_enum =3D 0; - else if ((mask & value) !=3D 0) - flag_enum =3D 0; - else - mask |=3D value; } =20 /* If we already know that the enum type is neither unsigned, nor diff --git a/gdb/testsuite/gdb.base/printcmds.c b/gdb/testsuite/gdb.base/pr= intcmds.c index f0b4fa4b86b1..81d2efe1a037 100644 --- a/gdb/testsuite/gdb.base/printcmds.c +++ b/gdb/testsuite/gdb.base/printcmds.c @@ -99,9 +99,10 @@ volatile enum some_volatile_enum some_volatile_enum =3D = enumvolval1; /* An enum considered as a "flag enum". */ enum flag_enum { - FE_NONE =3D 0x00, - FE_ONE =3D 0x01, - FE_TWO =3D 0x02, + FE_NONE =3D 0x00, + FE_ONE =3D 0x01, + FE_TWO =3D 0x02, + FE_TWO_LEGACY =3D 0x02, }; =20 enum flag_enum three =3D FE_ONE | FE_TWO; --=20 2.25.0