See theinstructions for how to check out and build Chromium for iOS.
The Chromium projects use buildbot for continuous integration. This doc starts with an overview of the system, then gives detailed explanations about each part.
Commits are made using thecommit queue, which triggers a series of try jobs to compile and test the proposed patch against Chromium tip of tree before actually making the commit. If the try jobs succeed the patch is committed. A newly committed change triggers the builders (or “bots”) to compile and test the change again.
Bots are slaves attached to a buildbot master (or “waterfall”). A buildbot master is a server which polls for commits to a repository and triggers workers to compile and test new commits whenever they are detected.chromium.mac is the main waterfall for Mac desktop and iOS.tryserver.chromium.mac serves as the try server for Mac desktop and iOS.
The bots know how to check out a given revision of Chromium, compile, and test.
The masters are configured intools/build, a separate repository which contains various infra-related scripts.
chromium.mac uses aGitilesPoller which polls the Chromium repository for new commits using thegitiles interface. When a new commit is detected, the bots are triggered.
The bots runrecipes, which are scripts that specify their sequence of steps located intools/build. An iOS-specificrecipe module contains common functionality that the variousiOS recipes use.
Because the recipes live in another repository, changes to the recipes don‘t go through the Chromiumcommit queue and aren’t tested on thetry server. In order to allow bot changes to be tested by the commit queue, the recipes for iOS are generic instead of bot-specific, and rely on configuration files which live in master-specific JSON config files located insrc/ios/build/bots. These configs define thegn_args to use during compilation as well as the tests to run.
Thetest runner is the script which installs and runs the tests, interprets the results, and collects any files emitted by the test (“test data”). It can be found insrc/ios/build/bots/scripts, which means changes to the test runner can be tested on thetry server.
Reclient is the distributed build system used by Chromium. It reduces compilation time by avoiding recompilation of objects which have already been compiled elsewhere.
Tests run onswarming, a distributed test system used by Chromium. After compilation, configured tests will be zipped up along with their necessary dependencies (“isolated”) and sent to theswarming server for execution. The server issues tasks to its attached workers for execution. The bots themselves don't run any tests, they trigger tests to be run remotely on the swarming server, then wait and display the results. This allows multiple tests to be executed in parallel.
Try bots are bots which test proposed patches which are not yet committed.
Requesttry job access in order to trigger try jobs against your patch. The relevant try bots for an iOS patch areios-device andios-simulator. These bots can be found on the Mac-specifictry server. A try job is said to succeed when the build passes (i.e. when the bot successfully compiles and tests the patch).
ios-device compiles for the iOS device architecture (arm64) and runs no tests. A build is considered successful so long as compilation is successful.
ios-simulator compiles for the iOS simulator architecture (x86_64), and runs tests in the iOSsimulator. A build is considered successful when both compilation and all configured tests succeed.
ios-device andios-simulator both compile using the version ofclang defined by theCLANG_REVISION in the Chromium tree.
Triggering a try job and collecting its results is accomplished usingbuildbucket. The service allows for build requests to be put into buckets. A request in this context is a set of properties indicating things such as where to get the patch. The try bots are set up to poll a particular bucket for build requests which they execute and post the results of.
In addition to reclient, the try bots use another time-saving mechanism called theanalyzer to determine the subset of compilation targets affected by the patch that need to be compiled in order to run the affected tests. If a patch is determined not to affect a certain test target, compilation and execution of the test target will be skipped.
See theconfigs code location for where to find the config files for the bots. The config files are JSON which describe how the bot should compile and which tests it should run. The config files are located in the configs directory. The configs directory contains a named directory for each master. For example:
$ ls ios/build/botsOWNERS scripts tests chromium.fyi chromium.mac
In this case, configs are defined for iOS bots onchromium.fyi andchromium.mac. Inside each master-specific directory are JSON config files named after each bot. For example:
$ ls ios/build/bots/chromium.macios-device.json ios-simulator.json
Theios-device bot onchromium.mac will read its configuration fromchromium.mac/ios-device.json in the configs directory.
{"comments":["Sample config for a bot."],"gn_args":["is_debug=true","target_cpu=\"x64\"","target_environment=\"simulator\""],"tests":[{"app":"ios_chrome_unittests","device type":"iPhone 5s","os":"11.0","xcode build version":"9A235"}]}
Thecomments key is optional and defines a list of strings which can be used to annotate the config. You may want to explain why the bot exists and what it's doing, particularly if there are extensive and atypicalgn_args.
Thegn_args key is a required list of arguments to pass toGN to generate the build files. Two GN args are required,is_debug andtarget_cpu. Useis_debug to define whether to compile for Debug or Release, andtarget_cpu to define whether to compile for x64 or arm64.target_environment is used to define whether to compile for simulator or device (as it cannot be deduced from the cpu architecture as there exists both x64 and arm64 macOS devices). The iOS bots typically perform Debug builds for the same architecture as the machine running the tests (usually x64), and Release builds for arm64.
Thetests key is an optional list of dictionaries defining tests to run. There are two types of test dictionary,app andinclude. Anapp dict defines a specific compiled app to run, for example:
"tests":[{"app":"ios_chrome_unittests","device type":"iPhone 5s","os":"11.0","xcode build version":"9A235"}]
This dict says to runios_chrome_unittests on aniPhone 5s running iOS11.0 using Xcode build version9A235. A test dict may optionally define a list oftest args, which are arguments to pass directly to the test on the command line, and it may define a boolean valuexctest to indicate whether the test is anxctest (default if unspecified isfalse). For example:
"tests":[{"app":"ios_chrome_unittests","device type":"iPhone 5s","os":"11.0","test args":["--foo","--bar"],"xcode build version":"9A235"},{"app":"ios_chrome_integration_egtests","device type":"iPhone 5s","os":"11.0","xcode build version":"9A235","xctest":true}]
This defines two tests to run, firstios_chrome_unittests will be run with--foo and--bar passed directly to the test on the command line. Next,ios_chrome_integration_egtests will be run as an xctest."xctest": true must be specified for all xctests, it is an error to try and launch an xctest as a regular test.
Aninclude dict defines a list of tests to import from thetests subdirectory in the configs directory. For example:
"tests":[{"include":"common_tests.json","device type":"iPhone 5s","os":"11.0","xcode build version":"9A235"}]
This dict says to import the list of tests from thetests subdirectory and run each one on aniPhone 5s running iOS11.0 using Xcode9A235. Here's whatcommon_tests.json might look like:
"tests":[{"app":"ios_chrome_unittests"},{"app":"ios_net_unittests"},{"app":"ios_web_unittests"},]
Includes may contain other keys besidesapp which can then be omitted in the bot config. For example ifcommon_tests.json specifies:
"tests":[{"app":"ios_chrome_integration_egtests","xctest":true,"xcode build version":"9A235"}]
Then the bot config may omit thexctest orxcode build version keys, for example:
{"comments":["Sample config for a bot."],"gn_args":["is_debug=true","target_cpu=\"x64\"","target_environment=\"simulator\""],"tests":[{"include":"common_tests.json","device type":"iPhone 5s","os":"11.0"}]}
Includes are not recursive, socommon_tests.json may not itself include anyinclude dicts.
Some keywords such asxcode build version can also be set globally per build:
{"comments":["Sample config for a bot."],"gn_args":["is_debug=true","target_cpu=\"x64\"","target_environment=\"simulator\""],"xcode build version":"9A235","tests":[{"app":"ios_chrome_integration_egtests","device type":"iPhone 5s","os":"11.0"}]}
A bot may be configured to upload compiled artifacts. This is defined by theupload key. For example:
{"comments":["Sample config for a bot which uploads artifacts."],"gn_args":["is_debug=true","target_cpu=\"x64\"","target_environment=\"simulator\""],"upload":[{"artifact":"Chromium.breakpad","bucket":"my-gcs-bucket",},{"artifact":"Chromium.app","bucket":"my-gcs-bucket","compress":true,},{"artifact":"Chromium.breakpad","symupload":"https://clients2.google.com/cr/symbol",}]}
After compilation, the bot will upload three artifacts. First theChromium.breakpad symbols will be uploaded togs://my-gcs-bucket/<buildername>/<buildnumber>/Chromium.breakpad. NextChromium.app will be tarred, gzipped, and uploaded togs://my-gcs-bucket/<buildername>/<buildnumber>/Chromium.tar.gz. Finally theChromium.breakpad symbols will be uploaded to thebreakpad crash reporting server where they can be used to symbolicate stack traces.
Ifartifact is a directory, you must specify"compress": true.