Rework definitions of 'gn_all' and related targets.

The 'gn_all' target in src/BUILD.gn didn't actually build everything,
which could be confusing. This patch renames the target to 'both_gn_and_gyp'
which should make the intent clearer, and reworks the accompanyhing
targets in both the GN and GYP builds to match.

R=jam@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1104213005

Cr-Commit-Position: refs/heads/master@{#327411}

BUILD.gn

@@ -24,20 +24,40 @@ declare_args() {
   root_extra_deps = []
 }
 
-# The "gn_all" target should list every root target (target that
-# nothing else depends on) built by both GN and GYP. One should
-# be able to run 'ninja gn_all gn_only gn_groups' and then run
-# 'ninja' a second time and have the second ninja invocation do nothing.
+# This file defines the following three main targets:
 #
-# In addition, the "gn_all" target serves to pull in all of the other
-# build files needed for the build.
+# "both_gn_and_gyp" should list every root target (target that nothing else
+# depends on) built by GN that is also built in the GYP build.
 #
-# TODO(GYP): make sure that the above is true and there are scripts run
-# on the bots that enforce this.
+# "gn_all" should (transitively) cause everything to be built; if you run
+# 'ninja gn_all' and then 'ninja all', the second build should do no work.
+#
+# "gn_only" should list every root target that is *not* intended to be built
+# in a GYP build. Because GN has different rules for deciding what an 'all'
+# build is, this may end up including targets that are actually defined in a
+# GYP build but not dependencies of GYP's "all" (and so not actually built).
+#
+# TODO(GYP): crbug.com/481694. Make sure that the above is true and there are
+# scripts run on the bots that enforce this. Once the GYP migration is over,
+# we can collapse all of these targets as desired.
 
 group("gn_all") {
   testonly = true
 
+  deps = [
+    ":both_gn_and_gyp",
+    ":gn_only",
+  ]
+}
+
+# The "both_gn_and_gyp" target should reflect every target that is built
+# in both the GN and GYP builds, and ideally it should match the
+# "both_gn_and_gyp" target in build/gn_migration.gypi line-for-line.
+#
+# TODO(GYP): Add build steps that check and enforce this on the bots.
+group("both_gn_and_gyp") {
+  testonly = true
+
   deps = [
     "//base:base_unittests",
     "//cc:cc_unittests",
@@ -62,7 +82,6 @@ group("gn_all") {
     "//ipc:ipc_tests",
     "//ipc/mojo:ipc_mojo_unittests",
     "//jingle:jingle_unittests",
-    "//mandoline:mandoline_all",
     "//media:media_unittests",
     "//media/cast:cast_unittests",
     "//mojo",
@@ -553,7 +572,9 @@ group("gn_all") {
 group("gn_only") {
   testonly = true
 
-  deps = []
+  deps = [
+    "//mandoline:mandoline_all",
+  ]
 
   if (!is_android && !is_ios) {
     deps += [ "//components/proximity_auth:proximity_auth_unittests" ]

build/gn_migration.gypi

@@ -2,36 +2,40 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# This file defines three targets that we are using to
-# track the progress of the GYP->GN migration:
+# This file defines five targets that we are using to track the progress of the
+# GYP->GN migration:
 #
-# If you run 'ninja gn_build gyp_remaining gyp_groups', and then
-# run 'ninja', the second ninja invocation should do nothing. This
-# indicates that everything built by a ninja build is in fact
-# listed in one of these targets.
+# 'both_gn_and_gyp' lists what GN is currently capable of building and should
+# match the 'both_gn_and_gyp' target in //BUILD.gn.
 #
-# 'gn_all' lists what GN is currently capable of building and should
-#          match the 'gn_all' target in //BUILD.gn.
+# 'gyp_all' Should include everything built when building "all"; i.e., if you
+# type 'ninja gyp_all' and then 'ninja all', the second build should do
+# nothing. 'gyp_all' should just depend on the other four targets.
 #
-# 'gyp_remaining' lists all of the targets that still need to be converted,
-#          i.e., all of the other (non-empty) targets that a GYP build
-#          will build.
+# 'gyp_only' lists any targets that are not meant to be ported over to the GN
+# build.
 #
-# 'gyp_groups' lists any empty (group) targets in the GYP build that
-#          are not picked up by gn_all or gyp_remaining; this is a
-#          separate target to ensure that when we build it, only
-#          stamp targets file are we don't accidentally pick up something
-#          not listed in one of the other two targets.
+# 'gyp_remaining' lists all of the targets that still need to be converted,
+# i.e., all of the other (non-empty) targets that a GYP build will build.
 #
-# TODO(GYP), TODO(dpranke) Add a build step to the bot that enforces the
-#          above contracts.
+# TODO(GYP): crbug.com/481694. Add a build step to the bot that enforces the
+# above contracts.
 
 {
   'targets': [
     {
-      # This target should mirror the structure of //:gn_all
-      # as closely as possible, for ease of comparison.
-      'target_name': 'gn_all',
+      'target_name': 'gyp_all',
+      'type': 'none',
+      'dependencies': [
+        'both_gn_and_gyp',
+        'gyp_only',
+        'gyp_remaining',
+      ]
+    },
+    {
+      # This target should mirror the structure of //:both_gn_and_gyp
+      # in src/BUILD.gn as closely as possible, for ease of comparison.
+      'target_name': 'both_gn_and_gyp',
       'type': 'none',
       'dependencies': [
         '../base/base.gyp:base_i18n_perftests',
@@ -666,39 +670,6 @@
         }],
       ],
     },
-    {
-      # This target, when built, should cause no actual work
-      # to be done, just update a bunch of stamp files.
-      'target_name': 'gyp_groups',
-      'type': 'none',
-      'dependencies': [
-        'All',
-        'blink_tests',
-        'chromium_builder_asan',
-        'chromium_builder_chromedriver',
-        'chromium_builder_perf',
-        'chromium_builder_tests',
-        'chromium_builder_webrtc',
-        'chromium_gpu_builder',
-        'chromium_gpu_debug_builder',
-      ],
-      'conditions': [
-        ['use_aura==1', {
-          'dependencies': [
-            'aura_builder',
-          ]
-        }],
-        ['OS=="win"', {
-          'dependencies': [
-            'chromium_builder',
-            'chromium_builder_dbg_drmemory_win',
-            'chromium_builder_nacl_sdk',
-            'chromium_builder_lkgr_drmemory_win',
-            'chromium_builder_dbg_tsan_win',
-          ],
-        }],
-      ],
-    },
   ]
 }