From patchwork Mon Dec 12 20:30:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 61835 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 874A3383FF44 for ; Mon, 12 Dec 2022 20:33:18 +0000 (GMT) X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) by sourceware.org (Postfix) with ESMTPS id 7B025384DDA7 for ; Mon, 12 Dec 2022 20:31:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 7B025384DDA7 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=palves.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-f54.google.com with SMTP id b24-20020a05600c4a9800b003d21efdd61dso4770140wmp.3 for ; Mon, 12 Dec 2022 12:31:08 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=uT5xpq0uwWPvOdI8GRVyfoa0ue8fqNbWKSKXnVQwJw8=; b=DFCrgBjPssxqX013AnFZCyv0HTqII4Cd43g8svYBpY5xxRMU2zX/iXlpej5WcFupYH QrowsuoHkdM8y3lCOaIHhnJCqDyCboYF5vlotrNJu6ad2PcxQXJknu1MNMyCI0b6JjTf pJGkyGM7EPldlizbHIZFOmeKNJnOtJF7tFfyzzzuR5BeB5DX1LWKdnBFQrgm+YtZA/Rv vX7UgxNNK52Kb+0eCu912WYsPHfbNc/2KpEIswA4zgI/BajCiBozasv36UhNTI+CLhjl oG4Atjc7ua4g1JvEgzYhQe5/s3Fy1mRFS3b1Xf7noLuoCY3DkAqvWj/ibQcj2K1SZu/O TN6w== X-Gm-Message-State: ANoB5pnOLOLphq6eBGb+R19QM9NSxJgl13o+xahZ6x7B18P7rI7KDkdo Wmn6wU1+kIvO/nMAG+ypeXfB4ag9OG4VQw== X-Google-Smtp-Source: AA0mqf4ps6M7Stw8tfnaYFsiVoWvymVOL0PtYj6Ej9Jkxwdf4TrE4Vwo9udOF8z5od7Huhv2AgNN+w== X-Received: by 2002:a05:600c:4fc8:b0:3cf:614e:b587 with SMTP id o8-20020a05600c4fc800b003cf614eb587mr13709385wmq.26.1670877067242; Mon, 12 Dec 2022 12:31:07 -0800 (PST) Received: from localhost ([2001:8a0:f912:6700:afd9:8b6d:223f:6170]) by smtp.gmail.com with ESMTPSA id 13-20020a05600c228d00b003d1b4d957aasm10211695wmf.36.2022.12.12.12.31.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Dec 2022 12:31:06 -0800 (PST) From: Pedro Alves To: gdb-patches@sourceware.org Cc: Simon Marchi Subject: [PATCH 07/31] enum_flags to_string Date: Mon, 12 Dec 2022 20:30:37 +0000 Message-Id: <20221212203101.1034916-8-pedro@palves.net> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20221212203101.1034916-1-pedro@palves.net> References: <20221212203101.1034916-1-pedro@palves.net> MIME-Version: 1.0 X-Spam-Status: No, score=-10.2 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, GIT_PATCH_0, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, 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 X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces+patchwork=sourceware.org@sourceware.org Sender: "Gdb-patches" This commit introduces shared infrastructure that can be used to implement enum_flags -> to_string functions. With this, if we want to support converting a given enum_flags specialization to string, we just need to implement a function that provides the enumerator->string mapping, like so: enum some_flag { SOME_FLAG1 = 1 << 0, SOME_FLAG2 = 1 << 1, SOME_FLAG3 = 1 << 2, }; DEF_ENUM_FLAGS_TYPE (some_flag, some_flags); static std::string to_string (some_flags flags) { static constexpr some_flags::string_mapping mapping[] = { MAP_ENUM_FLAG (SOME_FLAG1), MAP_ENUM_FLAG (SOME_FLAG2), MAP_ENUM_FLAG (SOME_FLAG3), }; return flags.to_string (mapping); } .. and then to_string(SOME_FLAG2 | SOME_FLAG3) produces a string like "0x6 [SOME_FLAG2 SOME_FLAG3]". If we happen to forget to update the mapping array when we introduce a new enumerator, then the string representation will pretty-print the flags it knows about, and then the leftover flags in hex (one single number). For example, if we had missed mapping SOME_FLAG2 above, we'd end up with: to_string(SOME_FLAG2 | SOME_FLAG3) => "0x6 [SOME_FLAG2 0x4]"); Other than in the unit tests included, no actual usage of the functionality is added in this commit. Approved-By: Simon Marchi Change-Id: I835de43c33d13bc0c95132f42c3f97318b875779 --- gdb/unittests/enum-flags-selftests.c | 69 +++++++++++++++++++++++++--- gdbsupport/enum-flags.h | 66 ++++++++++++++++++++++++++ 2 files changed, 129 insertions(+), 6 deletions(-) diff --git a/gdb/unittests/enum-flags-selftests.c b/gdb/unittests/enum-flags-selftests.c index f52fc7220a1..0fd35262469 100644 --- a/gdb/unittests/enum-flags-selftests.c +++ b/gdb/unittests/enum-flags-selftests.c @@ -359,21 +359,47 @@ CHECK_VALID (true, bool, NF (1) == char (1)) enum test_flag { - FLAG1 = 1 << 1, - FLAG2 = 1 << 2, - FLAG3 = 1 << 3, + FLAG1 = 1 << 0, + FLAG2 = 1 << 1, + FLAG3 = 1 << 2, + FLAG4 = 1 << 3, }; enum test_uflag : unsigned { - UFLAG1 = 1 << 1, - UFLAG2 = 1 << 2, - UFLAG3 = 1 << 3, + UFLAG1 = 1 << 0, + UFLAG2 = 1 << 1, + UFLAG3 = 1 << 2, + UFLAG4 = 1 << 3, }; DEF_ENUM_FLAGS_TYPE (test_flag, test_flags); DEF_ENUM_FLAGS_TYPE (test_uflag, test_uflags); +/* to_string enumerator->string mapping functions used to test + enum_flags::to_string. These intentionally miss mapping a couple + enumerators each (xFLAG2, xFLAG4). */ + +static std::string +to_string_flags (test_flags flags) +{ + static constexpr test_flags::string_mapping mapping[] = { + MAP_ENUM_FLAG (FLAG1), + MAP_ENUM_FLAG (FLAG3), + }; + return flags.to_string (mapping); +} + +static std::string +to_string_uflags (test_uflags flags) +{ + static constexpr test_uflags::string_mapping mapping[] = { + MAP_ENUM_FLAG (UFLAG1), + MAP_ENUM_FLAG (UFLAG3), + }; + return flags.to_string (mapping); +} + static void self_test () { @@ -581,6 +607,37 @@ self_test () SELF_CHECK (ok); } + + /* Check string conversion. */ + { + SELF_CHECK (to_string_uflags (0) + == "0x0 []"); + SELF_CHECK (to_string_uflags (UFLAG1) + == "0x1 [UFLAG1]"); + SELF_CHECK (to_string_uflags (UFLAG1 | UFLAG3) + == "0x5 [UFLAG1 UFLAG3]"); + SELF_CHECK (to_string_uflags (UFLAG1 | UFLAG2 | UFLAG3) + == "0x7 [UFLAG1 UFLAG3 0x2]"); + SELF_CHECK (to_string_uflags (UFLAG2) + == "0x2 [0x2]"); + /* Check that even with multiple unmapped flags, we only print one + unmapped hex number (0xa, in this case). */ + SELF_CHECK (to_string_uflags (UFLAG1 | UFLAG2 | UFLAG3 | UFLAG4) + == "0xf [UFLAG1 UFLAG3 0xa]"); + + SELF_CHECK (to_string_flags (0) + == "0x0 []"); + SELF_CHECK (to_string_flags (FLAG1) + == "0x1 [FLAG1]"); + SELF_CHECK (to_string_flags (FLAG1 | FLAG3) + == "0x5 [FLAG1 FLAG3]"); + SELF_CHECK (to_string_flags (FLAG1 | FLAG2 | FLAG3) + == "0x7 [FLAG1 FLAG3 0x2]"); + SELF_CHECK (to_string_flags (FLAG2) + == "0x2 [0x2]"); + SELF_CHECK (to_string_flags (FLAG1 | FLAG2 | FLAG3 | FLAG4) + == "0xf [FLAG1 FLAG3 0xa]"); + } } } /* namespace enum_flags_tests */ diff --git a/gdbsupport/enum-flags.h b/gdbsupport/enum-flags.h index cd500f55ff3..8546b6e75f2 100644 --- a/gdbsupport/enum-flags.h +++ b/gdbsupport/enum-flags.h @@ -130,6 +130,17 @@ class enum_flags typedef E enum_type; typedef typename enum_underlying_type::type underlying_type; + /* For to_string. Maps one enumerator of E to a string. */ + struct string_mapping + { + E flag; + const char *str; + }; + + /* Convenience for to_string implementations, to build a + string_mapping array. */ +#define MAP_ENUM_FLAG(ENUM_FLAG) { ENUM_FLAG, #ENUM_FLAG } + public: /* Allow default construction. */ constexpr enum_flags () @@ -183,6 +194,18 @@ class enum_flags /* Binary operations involving some unrelated type (which would be a bug) are implemented as non-members, and deleted. */ + /* Convert this object to a std::string, using MAPPING as + enumerator-to-string mapping array. This is not meant to be + called directly. Instead, enum_flags specializations should have + their own to_string function wrapping this one, thus hidding the + mapping array from callers. + + Note: this is defined outside the template class so it can use + the global operators for enum_type, which are only defined after + the template class. */ + template + std::string to_string (const string_mapping (&mapping)[N]) const; + private: /* Stored as enum_type because GDB knows to print the bit flags neatly if the enum values look like bit flags. */ @@ -415,6 +438,49 @@ template > void operator>> (const enum_flags &, const any_type &) = delete; +template +template +std::string +enum_flags::to_string (const string_mapping (&mapping)[N]) const +{ + enum_type flags = raw (); + std::string res = hex_string (flags); + res += " ["; + + bool need_space = false; + for (const auto &entry : mapping) + { + if ((flags & entry.flag) != 0) + { + /* Work with an unsigned version of the underlying type, + because if enum_type's underlying type is signed, op~ + won't be defined for it, and, bitwise operations on + signed types are implementation defined. */ + using uns = typename std::make_unsigned::type; + flags &= (enum_type) ~(uns) entry.flag; + + if (need_space) + res += " "; + res += entry.str; + + need_space = true; + } + } + + /* If there were flags not included in the mapping, print them as + a hex number. */ + if (flags != 0) + { + if (need_space) + res += " "; + res += hex_string (flags); + } + + res += "]"; + + return res; +} + #else /* __cplusplus */ /* In C, the flags type is just a typedef for the enum type. */