docs/ios_infra.md - chromium/src - Git at Google

 # Continuous build and test infrastructure for Chromium for iOS

 See the [instructions] 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.

 [TOC]

 ## Overview

 Commits are made using the [commit 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

 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.

 ### Code location

 #### Master configs

 The masters are configured in [tools/build], a separate repository which
 contains various infra-related scripts.

 #### Pollers

 [chromium.mac] uses a `GitilesPoller` which polls the Chromium repository for
 new commits using the [gitiles] interface. When a new commit is detected, the
 bots are triggered.

 #### Recipes

 The bots run [recipes], which are scripts that specify their sequence of steps
 located in [tools/build]. An iOS-specific [recipe module] contains common
 functionality that the various [iOS recipes] use.

 #### Configs

 Because the recipes live in another repository, changes to the recipes don't
 go through the Chromium [commit queue] and aren't tested on the [try 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 in [src/ios/build/bots].
 These configs define the `gn_args` to use during compilation as well as the
 tests to run.

 #### Scripts

 The [test 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 in [src/ios/build/bots/scripts], which means changes to the test runner
 can be tested on the [try server].

 ### Compiling with goma

 Goma is the distributed build system used by Chromium. It reduces compilation
 time by avoiding recompilation of objects which have already been compiled
 elsewhere.

 ### Testing with swarming

 Tests run on [swarming], a distributed test system used by Chromium. After
 compilation, configured tests will be zipped up along with their necessary
 dependencies ("isolated") and sent to the [swarming 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

 Try bots are bots which test proposed patches which are not yet committed.

 Request [try job access] in order to trigger try jobs against your patch. The
 relevant try bots for an iOS patch are `ios-device`, `ios-device-xcode-clang`,
 `ios-simulator`, and `ios-simulator-xcode-clang`. These bots can be found on
 the Mac-specific [try 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` and `ios-device-xcode-clang` both compile for the iOS device
 architecture (ARM), and neither run any tests. A build is considered successful
 so long as compilation is successful.

 `ios-simulator` and `ios-simulator-xcode-clang` both compile for the iOS
 simulator architecture (x86), and run tests in the iOS [simulator]. A build is
 considered successful when both compilation and all configured test succeed.

 `ios-device` and `ios-simulator` both compile using the version of [clang]
 defined by the `CLANG_REVISION` in the Chromium tree.

 `ios-device-xcode-clang` and `ios-simulator-xcode-clang` both compile using the
 version of clang that ships with Xcode.

 ### Scheduling try jobs using buildbucket

 Triggering a try job and collecting its results is accomplished using
 [buildbucket]. 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.

 ### Compiling with the analyzer

 In addition to goma, the try bots use another time-saving mechanism called the
 [analyzer] 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.

 [analyzer]: ../tools/mb
 [buildbucket]: https://cr-buildbucket.appspot.com
 [chromium.mac]: https://build.chromium.org/p/chromium.mac
 [clang]: ../tools/clang
 [commit queue]: https://dev.chromium.org/developers/testing/commit-queue
 [gitiles]: https://gerrit.googlesource.com/gitiles
 [instructions]: ./ios_build_instructions.md
 [iOS recipes]: https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipes/ios
 [recipe module]: https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipe_modules/ios
 [recipes]: https://chromium.googlesource.com/infra/infra/+/HEAD/doc/users/recipes.md
 [simulator]: https://developer.apple.com/library/content/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html
 [src/ios/build/bots]: ../ios/build/bots
 [src/ios/build/bots/scripts]: ../ios/build/bots/scripts
 [swarming]: https://github.com/luci/luci-py/tree/master/appengine/swarming
 [swarming server]: https://chromium-swarm.appspot.com
 [test runner]: ../ios/build/bots/scripts/test_runner.py
 [tools/build]: https://chromium.googlesource.com/chromium/tools/build
 [try job access]: https://www.chromium.org/getting-involved/become-a-committer#TOC-Try-job-access
 [try server]: https://build.chromium.org/p/tryserver.chromium.mac/waterfall
 [tryserver.chromium.mac]: https://build.chromium.org/p/tryserver.chromium.mac/waterfall
	# Continuous build and test infrastructure for Chromium for iOS

	See the [instructions] 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.

	[TOC]

	## Overview

	Commits are made using the [commit 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

	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.

	### Code location

	#### Master configs

	The masters are configured in [tools/build], a separate repository which
	contains various infra-related scripts.

	#### Pollers

	[chromium.mac] uses a `GitilesPoller` which polls the Chromium repository for
	new commits using the [gitiles] interface. When a new commit is detected, the
	bots are triggered.

	#### Recipes

	The bots run [recipes], which are scripts that specify their sequence of steps
	located in [tools/build]. An iOS-specific [recipe module] contains common
	functionality that the various [iOS recipes] use.

	#### Configs

	Because the recipes live in another repository, changes to the recipes don't
	go through the Chromium [commit queue] and aren't tested on the [try 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 in [src/ios/build/bots].
	These configs define the `gn_args` to use during compilation as well as the
	tests to run.

	#### Scripts

	The [test 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 in [src/ios/build/bots/scripts], which means changes to the test runner
	can be tested on the [try server].

	### Compiling with goma

	Goma is the distributed build system used by Chromium. It reduces compilation
	time by avoiding recompilation of objects which have already been compiled
	elsewhere.

	### Testing with swarming

	Tests run on [swarming], a distributed test system used by Chromium. After
	compilation, configured tests will be zipped up along with their necessary
	dependencies ("isolated") and sent to the [swarming 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

	Try bots are bots which test proposed patches which are not yet committed.

	Request [try job access] in order to trigger try jobs against your patch. The
	relevant try bots for an iOS patch are `ios-device`, `ios-device-xcode-clang`,
	`ios-simulator`, and `ios-simulator-xcode-clang`. These bots can be found on
	the Mac-specific [try 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` and `ios-device-xcode-clang` both compile for the iOS device
	architecture (ARM), and neither run any tests. A build is considered successful
	so long as compilation is successful.

	`ios-simulator` and `ios-simulator-xcode-clang` both compile for the iOS
	simulator architecture (x86), and run tests in the iOS [simulator]. A build is
	considered successful when both compilation and all configured test succeed.

	`ios-device` and `ios-simulator` both compile using the version of [clang]
	defined by the `CLANG_REVISION` in the Chromium tree.

	`ios-device-xcode-clang` and `ios-simulator-xcode-clang` both compile using the
	version of clang that ships with Xcode.

	### Scheduling try jobs using buildbucket

	Triggering a try job and collecting its results is accomplished using
	[buildbucket]. 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.

	### Compiling with the analyzer

	In addition to goma, the try bots use another time-saving mechanism called the
	[analyzer] 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.

	[analyzer]: ../tools/mb
	[buildbucket]: https://cr-buildbucket.appspot.com
	[chromium.mac]: https://build.chromium.org/p/chromium.mac
	[clang]: ../tools/clang
	[commit queue]: https://dev.chromium.org/developers/testing/commit-queue
	[gitiles]: https://gerrit.googlesource.com/gitiles
	[instructions]: ./ios_build_instructions.md
	[iOS recipes]: https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipes/ios
	[recipe module]: https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipe_modules/ios
	[recipes]: https://chromium.googlesource.com/infra/infra/+/HEAD/doc/users/recipes.md
	[simulator]: https://developer.apple.com/library/content/documentation/IDEs/Conceptual/iOS_Simulator_Guide/Introduction/Introduction.html
	[src/ios/build/bots]: ../ios/build/bots
	[src/ios/build/bots/scripts]: ../ios/build/bots/scripts
	[swarming]: https://github.com/luci/luci-py/tree/master/appengine/swarming
	[swarming server]: https://chromium-swarm.appspot.com
	[test runner]: ../ios/build/bots/scripts/test_runner.py
	[tools/build]: https://chromium.googlesource.com/chromium/tools/build
	[try job access]: https://www.chromium.org/getting-involved/become-a-committer#TOC-Try-job-access
	[try server]: https://build.chromium.org/p/tryserver.chromium.mac/waterfall
	[tryserver.chromium.mac]: https://build.chromium.org/p/tryserver.chromium.mac/waterfall