From patchwork Thu Feb 13 20:30:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Marchi X-Patchwork-Id: 38051 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-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@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 15:30:33 -0500 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 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 = 0, MEMBARRIER_CMD_GLOBAL = (1 << 0), MEMBARRIER_CMD_GLOBAL_EXPEDITED = (1 << 1), MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED = (1 << 2), MEMBARRIER_CMD_PRIVATE_EXPEDITED = (1 << 3), MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED = (1 << 4), MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE = (1 << 5), MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE = (1 << 6), /* Alias for header backward compatibility. */ MEMBARRIER_CMD_SHARED = 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=0bf999f9c5e74c7ecf9dafb527146601e5c848b9#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_info *die, struct die_info *child_die; int unsigned_enum = 1; int flag_enum = 1; - ULONGEST mask = 0; auto_obstack obstack; @@ -15533,10 +15532,6 @@ update_enumeration_type_from_children (struct die_info *die, if (nbits != 0 && nbits && nbits != 1) flag_enum = 0; - else if ((mask & value) != 0) - flag_enum = 0; - else - mask |= value; } /* 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/printcmds.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 = enumvolval1; /* An enum considered as a "flag enum". */ enum flag_enum { - FE_NONE = 0x00, - FE_ONE = 0x01, - FE_TWO = 0x02, + FE_NONE = 0x00, + FE_ONE = 0x01, + FE_TWO = 0x02, + FE_TWO_LEGACY = 0x02, }; enum flag_enum three = FE_ONE | FE_TWO;