Generate fully-qualified builder dimension for branched iOS builders.

iOS is going to build with Xcode 12 sdk in trunk builders, but branched
ci/try builders have to use Xcode 11. There are issues when using
Xcode 11 & Xcode 12 on one machine. Thus, we need to separate the
machines for iOS trunk and branched builders.

This CL adds an argument to builders.star to generate builder dimension
with project & bucket and uses the argument for iOS branched builders.

Credit to gbeaty@ for the change in "infra/config/lib/builders.star"
(patched from crrev/c/2360500)

Bug: 1115022
Change-Id: Ic682e3014073e07a9526e14997dd4c170f11d9de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2363691
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Zhaoyang Li <zhaoyangli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799299}

Author: zhaoyangli

infra/config/generated/cr-buildbucket.cfg

@@ -14284,7 +14284,7 @@ buckets {
       name: "ios-simulator"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator"
+      dimensions: "builder:chromium/ci-m84/ios-simulator"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.ci"
@@ -14315,7 +14315,7 @@ buckets {
       name: "ios-simulator-cronet"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-cronet"
+      dimensions: "builder:chromium/ci-m84/ios-simulator-cronet"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.ci"
@@ -14346,7 +14346,7 @@ buckets {
       name: "ios-simulator-full-configs"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-full-configs"
+      dimensions: "builder:chromium/ci-m84/ios-simulator-full-configs"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.ci"
@@ -16758,7 +16758,7 @@ buckets {
       name: "ios-simulator"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator"
+      dimensions: "builder:chromium/ci-m85/ios-simulator"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.ci"
@@ -16789,7 +16789,7 @@ buckets {
       name: "ios-simulator-cronet"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-cronet"
+      dimensions: "builder:chromium/ci-m85/ios-simulator-cronet"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.ci"
@@ -16820,7 +16820,7 @@ buckets {
       name: "ios-simulator-full-configs"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-full-configs"
+      dimensions: "builder:chromium/ci-m85/ios-simulator-full-configs"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.ci"
@@ -30020,7 +30020,7 @@ buckets {
       name: "ios-simulator"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator"
+      dimensions: "builder:chromium/try-m84/ios-simulator"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.try"
@@ -30059,7 +30059,7 @@ buckets {
       name: "ios-simulator-cronet"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-cronet"
+      dimensions: "builder:chromium/try-m84/ios-simulator-cronet"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.try"
@@ -30098,7 +30098,7 @@ buckets {
       name: "ios-simulator-full-configs"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-full-configs"
+      dimensions: "builder:chromium/try-m84/ios-simulator-full-configs"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.try"
@@ -32012,7 +32012,7 @@ buckets {
       name: "ios-simulator"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator"
+      dimensions: "builder:chromium/try-m85/ios-simulator"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.try"
@@ -32051,7 +32051,7 @@ buckets {
       name: "ios-simulator-cronet"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-cronet"
+      dimensions: "builder:chromium/try-m85/ios-simulator-cronet"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.try"
@@ -32090,7 +32090,7 @@ buckets {
       name: "ios-simulator-full-configs"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builder:ios-simulator-full-configs"
+      dimensions: "builder:chromium/try-m85/ios-simulator-full-configs"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-10.15"
       dimensions: "pool:luci.chromium.try"

infra/config/lib/builders.star

@@ -25,6 +25,7 @@ for use with the corresponding arguments to `builder`. Can also be accessed
 through `builders.cpu`, `builders.os` and `builders.goma` respectively.
 """
 
+load("//project.star", "settings")
 load("./args.star", "args")
 
 ################################################################################
@@ -242,6 +243,7 @@ defaults = args.defaults(
     configure_kitchen = False,
     cores = None,
     cpu = None,
+    fully_qualified_builder_dimension = False,
     goma_backend = None,
     goma_debug = False,
     goma_enable_ats = args.COMPUTE,
@@ -278,6 +280,7 @@ def builder(
         os = args.DEFAULT,
         builderless = args.DEFAULT,
         auto_builder_dimension = args.DEFAULT,
+        fully_qualified_builder_dimension = args.DEFAULT,
         cores = args.DEFAULT,
         cpu = args.DEFAULT,
         builder_group = args.DEFAULT,
@@ -329,6 +332,12 @@ def builder(
         machines devoted to the builder. If True, a dimension will be emitted of
         the form 'builder:<name>'. By default, considered True iff `builderless`
         is considered False.
+      * fully_qualified_builder_dimension - a boolean modifying the behavior of
+        auto_builder_dimension to generate a builder dimensions that is
+        fully-qualified with the project and bucket of the builder. If True, and
+        `auto_builder_dimension` is considered True, a dimension will be emitted
+        of the form 'builder:<project>/<bucket>/<name>'. By default, considered
+        False.
       * builder_group - a string with the group of the builder. Emits a property
         of the form 'builder_group:<builder_group>'. By default, considered None.
       * mastername - a string with the group of the builder. Emits a property
@@ -426,14 +435,24 @@ def builder(
     if builderless:
         dimensions["builderless"] = "1"
 
+    # bucket might be the args.COMPUTE sentinel value if the caller didn't set
+    # bucket in some way, which will result in a weird fully-qualified builder
+    # dimension, but it shouldn't matter because the call to luci.builder will
+    # fail without bucket being set
+    bucket = defaults.get_value("bucket", bucket)
+
     auto_builder_dimension = defaults.get_value(
         "auto_builder_dimension",
         auto_builder_dimension,
     )
     if auto_builder_dimension == args.COMPUTE:
         auto_builder_dimension = builderless == False
     if auto_builder_dimension:
-        dimensions["builder"] = name
+        fully_qualified_builder_dimension = defaults.get_value("fully_qualified_builder_dimension", fully_qualified_builder_dimension)
+        if fully_qualified_builder_dimension:
+            dimensions["builder"] = "{}/{}/{}".format(settings.project, bucket, name)
+        else:
+            dimensions["builder"] = name
 
     cores = defaults.get_value("cores", cores)
     if cores != None:
@@ -498,7 +517,6 @@ def builder(
         properties["$build/code_coverage"] = code_coverage
 
     kwargs = dict(kwargs)
-    bucket = defaults.get_value("bucket", bucket)
     if bucket != args.COMPUTE:
         kwargs["bucket"] = bucket
     executable = defaults.get_value("executable", executable)

infra/config/subprojects/chromium/versioned/m84/buckets/ci.star

@@ -379,6 +379,7 @@ ci.fyi_ios_builder(
         category = "cronet",
     ),
     executable = "recipe:chromium",
+    fully_qualified_builder_dimension = True,
     notifies = ["cronet"],
     properties = {
         "xcode_build_version": "11c29",
@@ -661,6 +662,7 @@ ci.mac_ios_builder(
         category = "ios|default",
         short_name = "sim",
     ),
+    fully_qualified_builder_dimension = True,
 )
 
 ci.mac_ios_builder(
@@ -669,6 +671,7 @@ ci.mac_ios_builder(
         category = "ios|default",
         short_name = "ful",
     ),
+    fully_qualified_builder_dimension = True,
 )
 
 ci.memory_builder(

infra/config/subprojects/chromium/versioned/m84/buckets/try.star

@@ -447,6 +447,7 @@ try_.chromium_mac_builder(
 try_.chromium_mac_ios_builder(
     name = "ios-simulator",
     executable = "recipe:chromium_trybot",
+    fully_qualified_builder_dimension = True,
     properties = {
         "xcode_build_version": "11e146",
     },
@@ -456,6 +457,7 @@ try_.chromium_mac_ios_builder(
 try_.chromium_mac_ios_builder(
     name = "ios-simulator-cronet",
     executable = "recipe:chromium_trybot",
+    fully_qualified_builder_dimension = True,
     tryjob = try_.job(
         location_regexp = [
             ".+/[+]/components/cronet/.+",
@@ -471,6 +473,7 @@ try_.chromium_mac_ios_builder(
 try_.chromium_mac_ios_builder(
     name = "ios-simulator-full-configs",
     executable = "recipe:chromium_trybot",
+    fully_qualified_builder_dimension = True,
     tryjob = try_.job(
         location_regexp = [
             ".+/[+]/ios/.+",

infra/config/subprojects/chromium/versioned/m85/buckets/ci.star

@@ -439,6 +439,7 @@ ci.fyi_ios_builder(
     console_view_entry = ci.console_view_entry(
         category = "cronet",
     ),
+    fully_qualified_builder_dimension = True,
     executable = "recipe:chromium",
     notifies = ["cronet"],
     properties = {
@@ -722,6 +723,7 @@ ci.mac_ios_builder(
         category = "ios|default",
         short_name = "sim",
     ),
+    fully_qualified_builder_dimension = True,
 )
 
 ci.mac_ios_builder(
@@ -730,6 +732,7 @@ ci.mac_ios_builder(
         category = "ios|default",
         short_name = "ful",
     ),
+    fully_qualified_builder_dimension = True,
 )
 
 ci.memory_builder(

infra/config/subprojects/chromium/versioned/m85/buckets/try.star

@@ -459,6 +459,7 @@ try_.chromium_mac_builder(
 try_.chromium_mac_ios_builder(
     name = "ios-simulator",
     executable = "recipe:chromium_trybot",
+    fully_qualified_builder_dimension = True,
     properties = {
         "xcode_build_version": "11e146",
     },
@@ -468,6 +469,7 @@ try_.chromium_mac_ios_builder(
 try_.chromium_mac_ios_builder(
     name = "ios-simulator-cronet",
     executable = "recipe:chromium_trybot",
+    fully_qualified_builder_dimension = True,
     tryjob = try_.job(
         location_regexp = [
             ".+/[+]/components/cronet/.+",
@@ -483,6 +485,7 @@ try_.chromium_mac_ios_builder(
 try_.chromium_mac_ios_builder(
     name = "ios-simulator-full-configs",
     executable = "recipe:chromium_trybot",
+    fully_qualified_builder_dimension = True,
     tryjob = try_.job(
         location_regexp = [
             ".+/[+]/ios/.+",