From patchwork Mon Aug 12 18:24:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Higgins X-Patchwork-Id: 11090629 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 38D75112C for ; Mon, 12 Aug 2019 18:26:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2BB4A2624D for ; Mon, 12 Aug 2019 18:26:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1F25328451; Mon, 12 Aug 2019 18:26:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 977552624D for ; Mon, 12 Aug 2019 18:26:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726479AbfHLSYl (ORCPT ); Mon, 12 Aug 2019 14:24:41 -0400 Received: from mail-qk1-f201.google.com ([209.85.222.201]:49824 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726185AbfHLSYk (ORCPT ); Mon, 12 Aug 2019 14:24:40 -0400 Received: by mail-qk1-f201.google.com with SMTP id l14so93922568qke.16 for ; Mon, 12 Aug 2019 11:24:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=9mTljNvnyVjruVsrPNgUh53D69b4G0uh+rf/XKR7JZU=; b=LnitzvMrBNB6LXONfL+PvwD9Ikk/vWzKySiopcnIrxQgVqiY5+jLuNhJ9ZjzPBotY0 Y0ntD2wGlkRwN/WqMUqePvF0CIftp/LQyZGsiE/rMamSPolRPy/gI1hWyTFrYjj8Az0S iO+WLGSlSP4wDNeKPbhpSACldOlKIN0vm2AbpOTth5lwOi+wd5FtPBH+6DMV4BF7XZ5u DCsO7wsqQZmhB7r+8C/SPCwSznOeI9ADcdzFPsEOZDZ9rWtgCf15F0uO/DhlcKvYD1vS ikhy6UaROEOWv19ZHJDw8MIz7i0jbDy1yYL+vXOT6UpBhCm16LBtfsDmmxW8jdqFq7iG CYUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=9mTljNvnyVjruVsrPNgUh53D69b4G0uh+rf/XKR7JZU=; b=oeivt6XPdOvQ5lbPYdId4tkb6jTP55zYmD+0w/388nTapiw523LAMRz37gBe4V/ROV y8cZaEd755dQl2kAQDQR0Ugo4XGfw0TI/amSd0wm5wdnRsxYMDfZjzIbDLmzsvCkbXUv 2Tox1MgNQj1QyMNur7FKWS5E9K6iMtx3yHUthFq7//wt0jkD+tHu05dE+dO5vTnxqyTe XSgIqoAIsUq2V6/IcXs2NKQ7YrRERYz3Aspj1X6O3Y3mbbuJO5sq/p/LhxJrmTkr8TYh MZkUvOsxYz6laM4E1ZR+ozfya6iCn/t04gHWsSwW4R8+wFzp5Nqlqeyt/F09V6JKusN2 dAbw== X-Gm-Message-State: APjAAAWRyz9UTKflicNSQaGeNTvUPG8ZgMkFpqcHQVlow8qaWTsFM15+ IAtPOCk8BbrVNcb0YxOqXbdK/ihw5rpLO9CmS7rgkg== X-Google-Smtp-Source: APXvYqyX/pgx0ykzeqZ6WcltGi5sso4Ln3mqeyyrGVZaHJD02/SPkwtsL4N8Ya+oDgvaUGfqUr1kIJOvfUwiqmtqKuHktw== X-Received: by 2002:a37:4a88:: with SMTP id x130mr13395431qka.501.1565634278957; Mon, 12 Aug 2019 11:24:38 -0700 (PDT) Date: Mon, 12 Aug 2019 11:24:03 -0700 Message-Id: <20190812182421.141150-1-brendanhiggins@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.23.0.rc1.153.gdeed80330f-goog Subject: [PATCH v12 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework From: Brendan Higgins To: frowand.list@gmail.com, gregkh@linuxfoundation.org, jpoimboe@redhat.com, keescook@google.com, kieran.bingham@ideasonboard.com, mcgrof@kernel.org, peterz@infradead.org, robh@kernel.org, sboyd@kernel.org, shuah@kernel.org, tytso@mit.edu, yamada.masahiro@socionext.com Cc: devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, kunit-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-um@lists.infradead.org, Alexander.Levin@microsoft.com, Tim.Bird@sony.com, amir73il@gmail.com, dan.carpenter@oracle.com, daniel@ffwll.ch, jdike@addtoit.com, joel@jms.id.au, julia.lawall@lip6.fr, khilman@baylibre.com, knut.omang@oracle.com, logang@deltatee.com, mpe@ellerman.id.au, pmladek@suse.com, rdunlap@infradead.org, richard@nod.at, rientjes@google.com, rostedt@goodmis.org, wfg@linux.intel.com, Brendan Higgins Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP ## TL;DR This revision removes dependence on kunit_stream in favor of kunit_assert, as suggested by Stephen Boyd. kunit_assert provides a more structured interface for constructing messages and allows most required data to be stored on the stack for most expectations until it is determined that a failure message must be produced. As a part of introducing kunit_assert, expectations (KUNIT_EXPECT_*) and assertions (KUNIT_ASSERT_*) have been substantially refactored. Nevertheless, behavior should be the same. As this revision, adds a new patch, it, [PATCH v12 04/18], needs to be reviewed. All other patches have appropriate reviews and acks. I also rebased the patchset on v5.3-rc3. ## Background This patch set proposes KUnit, a lightweight unit testing and mocking framework for the Linux kernel. Unlike Autotest and kselftest, KUnit is a true unit testing framework; it does not require installing the kernel on a test machine or in a VM (however, KUnit still allows you to run tests on test machines or in VMs if you want[1]) and does not require tests to be written in userspace running on a host kernel. Additionally, KUnit is fast: From invocation to completion KUnit can run several dozen tests in about a second. Currently, the entire KUnit test suite for KUnit runs in under a second from the initial invocation (build time excluded). KUnit is heavily inspired by JUnit, Python's unittest.mock, and Googletest/Googlemock for C++. KUnit provides facilities for defining unit test cases, grouping related test cases into test suites, providing common infrastructure for running tests, mocking, spying, and much more. ### What's so special about unit testing? A unit test is supposed to test a single unit of code in isolation, hence the name. There should be no dependencies outside the control of the test; this means no external dependencies, which makes tests orders of magnitudes faster. Likewise, since there are no external dependencies, there are no hoops to jump through to run the tests. Additionally, this makes unit tests deterministic: a failing unit test always indicates a problem. Finally, because unit tests necessarily have finer granularity, they are able to test all code paths easily solving the classic problem of difficulty in exercising error handling code. ### Is KUnit trying to replace other testing frameworks for the kernel? No. Most existing tests for the Linux kernel are end-to-end tests, which have their place. A well tested system has lots of unit tests, a reasonable number of integration tests, and some end-to-end tests. KUnit is just trying to address the unit test space which is currently not being addressed. ### More information on KUnit There is a bunch of documentation near the end of this patch set that describes how to use KUnit and best practices for writing unit tests. For convenience I am hosting the compiled docs here[2]. Additionally for convenience, I have applied these patches to a branch[3]. The repo may be cloned with: git clone https://kunit.googlesource.com/linux This patchset is on the kunit/rfc/v5.3/v12 branch. ## Changes Since Last Version - Dropped patch "[PATCH v11 04/18] kunit: test: add kunit_stream a std::stream like logger" and replaced it with "[PATCH v12 04/18] kunit: test: add assertion printing library", which provides a totally new mechanism for constructing expectation/assertion failure messages. - Substantially refactored expectations and assertions definitions in [PATCH 05/18] and [PATCH 11/18] respectively. - Rebased patchset on v5.3-rc3. - Fixed a minor documentation bug. [1] https://google.github.io/kunit-docs/third_party/kernel/docs/usage.html#kunit-on-non-uml-architectures [2] https://google.github.io/kunit-docs/third_party/kernel/docs/ [3] https://kunit.googlesource.com/linux/+/kunit/rfc/v5.3/v12