tools/licenses/README.md - mirrors/engine - Git at Google

 # Update License Files

 ## Apply patch generated by CI
 If you're not working on a Linux box then you can't auto-generate license files. A workaround is provided via CI.

 Your build will fail one or more CI checks if your license files are not correct. Open the failing CI check. In the CI output you will find a patch diff that represents the changes that need to be made to your license files.

 IF (and only if!) the diff does not change _which_ licenses are being included, but only affects the `FILE:` metadata and so forth in the golden files, then you can click `Download full logs` (Github removes lines with only whitespaces, which invalidates the diff), copy this patch to a temporary patch file wherever you'd like, and then apply the patch to your repo:

 ```
 cd flutter/ci/licenses_golden
 patch -p2 < my/patch/file
 ```

 HOWEVER, if the actual content of the licenses changed then you will need to rerun the script from a Linux box to update the actual LICENSE file, as described below.

 ## Check for license changes (Only works on Linux)

 This script has two sets of output files: "goldens", which describe
 the current license state of the repository, and the actual real
 LICENSE file, which is what matters.

 We look at changes to the goldens to determine if there are any actual
 changes to the licenses.

 To update the goldens, make sure you've rebased your branch to the
 latest upstream main and then run the following in this directory:

 ```
 dart pub get
 gclient sync -D
 rm -rf ../../../out/licenses
 dart lib/main.dart --src ../../.. --out ../../../out/licenses --golden ../../ci/licenses_golden
 ```

 In order for the license script to work correctly, you need to remove
 any untracked files inside `engine/src` (the buildroot), not just
 `engine/src/flutter`.

 Once the script has finished, copy any affected files from
 `../../../out/licenses` to `../../ci/licenses_golden` and add them to
 your change, and examine the diffs to see what changed.

 ```
 cp ../../../out/licenses/* ../../ci/licenses_golden
 git diff
 ```

 If the only changes are to what files are included, then you're good
 to go. However, if any of the _licenses_ changed, whether new licenses
 are added, old ones removed, or any have their content changed in
 _any_ way (including, e.g., whitespace changes), or if the affected
 libraries change, **you must update the actual license file**.

 The `sky/packages/sky_engine/LICENSE` file is the one actually
 included in product releases and the one that should be updated any
 time the golden file changes in a way that involves changes to
 anything other than the `FILE` lines. To update this file, run:

 ```
 dart pub get
 gclient sync
 dart lib/main.dart --release --src ../../.. --out ../../../out/licenses > ../../sky/packages/sky_engine/LICENSE
 ```

 The bots do not verify that you did this step, it's important that you
 do it! When reviewing patches, if you see a change to the golden
 files, check to see if there's a corresponding change to the LICENSE
 file!
	# Update License Files

	## Apply patch generated by CI
	If you're not working on a Linux box then you can't auto-generate license files. A workaround is provided via CI.

	Your build will fail one or more CI checks if your license files are not correct. Open the failing CI check. In the CI output you will find a patch diff that represents the changes that need to be made to your license files.

	IF (and only if!) the diff does not change _which_ licenses are being included, but only affects the `FILE:` metadata and so forth in the golden files, then you can click `Download full logs` (Github removes lines with only whitespaces, which invalidates the diff), copy this patch to a temporary patch file wherever you'd like, and then apply the patch to your repo:

	```
	cd flutter/ci/licenses_golden
	patch -p2 < my/patch/file
	```

	HOWEVER, if the actual content of the licenses changed then you will need to rerun the script from a Linux box to update the actual LICENSE file, as described below.

	## Check for license changes (Only works on Linux)

	This script has two sets of output files: "goldens", which describe
	the current license state of the repository, and the actual real
	LICENSE file, which is what matters.

	We look at changes to the goldens to determine if there are any actual
	changes to the licenses.

	To update the goldens, make sure you've rebased your branch to the
	latest upstream main and then run the following in this directory:

	```
	dart pub get
	gclient sync -D
	rm -rf ../../../out/licenses
	dart lib/main.dart --src ../../.. --out ../../../out/licenses --golden ../../ci/licenses_golden
	```

	In order for the license script to work correctly, you need to remove
	any untracked files inside `engine/src` (the buildroot), not just
	`engine/src/flutter`.

	Once the script has finished, copy any affected files from
	`../../../out/licenses` to `../../ci/licenses_golden` and add them to
	your change, and examine the diffs to see what changed.

	```
	cp ../../../out/licenses/* ../../ci/licenses_golden
	git diff
	```

	If the only changes are to what files are included, then you're good
	to go. However, if any of the _licenses_ changed, whether new licenses
	are added, old ones removed, or any have their content changed in
	_any_ way (including, e.g., whitespace changes), or if the affected
	libraries change, you must update the actual license file.

	The `sky/packages/sky_engine/LICENSE` file is the one actually
	included in product releases and the one that should be updated any
	time the golden file changes in a way that involves changes to
	anything other than the `FILE` lines. To update this file, run:

	```
	dart pub get
	gclient sync
	dart lib/main.dart --release --src ../../.. --out ../../../out/licenses > ../../sky/packages/sky_engine/LICENSE
	```

	The bots do not verify that you did this step, it's important that you
	do it! When reviewing patches, if you see a change to the golden
	files, check to see if there's a corresponding change to the LICENSE
	file!