[build] Speed up debug and simulator builds by running steps on the prebuilt VM.

Only generating a snapshot really requires running the VM produced during the build.

Change-Id: Ic07bf8b61609c39c9e2dc910737ed56e64decd43
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/116749
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>

utils/application_snapshot.gni

@@ -74,11 +74,64 @@ template("_application_snapshot") {
   if (defined(invoker.output)) {
     output = invoker.output
   }
+
+  # Build the kernel file using the prebuilt VM to speed up the debug and
+  # simulator builds.
+  prebuilt_dart_action(target_name + "_dill") {
+    deps = extra_deps + [
+             "../../runtime/vm:kernel_platform_files($dart_host_toolchain)",
+             "../../runtime/vm:vm_platform",
+           ]
+    gen_kernel_script = "../../pkg/vm/bin/gen_kernel.dart"
+    platform_dill = "$root_out_dir/vm_platform_strong.dill"
+
+    inputs = extra_inputs + [
+               gen_kernel_script,
+               platform_dill,
+               main_dart,
+               dot_packages,
+             ]
+    output = "$root_gen_dir/$name.dart.dill"
+    outputs = [
+      output,
+    ]
+
+    depfile = "$output.d"
+    abs_depfile = rebase_path(depfile)
+    rebased_output = rebase_path(output, root_build_dir)
+    vm_args = [
+      "--depfile=$abs_depfile",
+      "--depfile_output_filename=$rebased_output",
+    ]
+
+    script = gen_kernel_script
+
+    args = [
+      "--packages=" + rebase_path(dot_packages),
+      "--platform=" + rebase_path(platform_dill),
+      "--no-aot",
+      "--no-embed-sources",
+      "--no-link-platform",
+      "--output=" + rebase_path(output),
+    ]
+    # TODO(bytecode): Remove special case for the kernel service once
+    # interpreter-compiled transitions no longer cause stack overflows in
+    # the language_2/deep_nesting* tests.
+    if (dart_platform_bytecode && (name != "kernel-service_snapshot")) {
+      args += [
+        "--gen-bytecode",
+        "--drop-ast",
+        "--bytecode-options=source-positions",
+      ]
+    }
+    args += [ rebase_path(main_dart) ]
+  }
+
   dart_action(target_name) {
-    deps = extra_deps
+    deps = extra_deps + [ ":${target_name}_dill" ]
     depfile = "$output.d"
 
-    script = main_dart
+    script = "$root_gen_dir/$name.dart.dill"
 
     inputs = extra_inputs
 
@@ -90,16 +143,14 @@ template("_application_snapshot") {
     abs_output = rebase_path(output, root_build_dir)
 
     vm_args = [
-      "--deterministic",
-      "--packages=$dot_packages",
-      "--snapshot=$abs_output",
-      "--snapshot-depfile=$abs_depfile",
-    ] + snapshot_vm_args
+                "--deterministic",
+                "--packages=$dot_packages",
+                "--snapshot=$abs_output",
+                "--snapshot-depfile=$abs_depfile",
+              ] + snapshot_vm_args
 
     if (dart_snapshot_kind == "kernel") {
-      vm_args += [
-        "--snapshot-kind=kernel",
-      ]
+      vm_args += [ "--snapshot-kind=kernel" ]
       assert(training_args != "", "Ignoring unused argument")
       args = []
     } else if (dart_snapshot_kind == "app-jit") {
@@ -141,9 +192,7 @@ template("application_snapshot") {
     if (!defined(invoker.deps)) {
       deps = []
     }
-    deps += [
-      "$_dart_root/utils/kernel-service:kernel-service"
-    ]
+    deps += [ "$_dart_root/utils/kernel-service:kernel-service" ]
   }
 }
 

utils/compiler/BUILD.gn

@@ -3,8 +3,8 @@
 # BSD-style license that can be found in the LICENSE file.
 
 import("../../utils/compile_platform.gni")
-import("../create_timestamp.gni")
 import("../application_snapshot.gni")
+import("../create_timestamp.gni")
 
 create_timestamp_file("dart2js_files_stamp") {
   path = rebase_path("../../pkg/compiler/lib")
@@ -21,18 +21,13 @@ create_timestamp_file("dartdoc_files_stamp") {
   output = "$target_gen_dir/dartdoc_files.stamp"
 }
 
-dart_action("dart2js_create_snapshot_entry") {
+prebuilt_dart_action("dart2js_create_snapshot_entry") {
   deps = [
     ":dart2js_files_stamp",
     ":dartdoc_files_stamp",
     ":runtime_lib_files_stamp",
   ]
 
-  # dart_action() needs kernel service snapshot to run in Dart 2 mode.
-  # This can't be added as a dependency to dart_action() itself as it will
-  # create a circular dependency.
-  deps += [ "../../utils/kernel-service:kernel-service" ]
-
   output_dir = rebase_path(target_gen_dir)
 
   script = "create_snapshot_entry.dart"

utils/dartdevc/BUILD.gn

@@ -30,7 +30,9 @@ application_snapshot("dartdevc") {
     ":dartdevc_kernel_sdk_outline",
   ]
 
-  inputs = [ sdk_dill ]
+  inputs = [
+    sdk_dill,
+  ]
 }
 
 sdk_lib_files = exec_script("../../tools/list_dart_files.py",
@@ -62,16 +64,11 @@ template("dart2js_compile") {
   abs_main = rebase_path(main)
   abs_output = rebase_path(out)
 
-  dart_action(target_name) {
+  prebuilt_dart_action(target_name) {
     deps = [
       "../compiler:compile_dart2js_platform",
     ]
 
-    # dart_action() needs kernel service snapshot to run in Dart 2 mode.
-    # This can't be added as a dependency to dart_action() itself as it will
-    # create a circular dependency.
-    deps += [ "../../utils/kernel-service:kernel-service" ]
-
     inputs = sdk_lib_files + compiler_files + dev_compiler_files + [
                "$root_out_dir/dart2js_platform.dill",
                "$root_out_dir/dart2js_outline.dill",
@@ -89,6 +86,7 @@ template("dart2js_compile") {
       "-m",
       "-o$abs_output",
       "--no-source-maps",
+      "--platform-binaries=" + rebase_path("$root_out_dir"),
     ]
   }
 }
@@ -211,8 +209,8 @@ prebuilt_dart_action("dartdevc_sdk") {
 group("dartdevc_test") {
   deps = [
     ":dartdevc",
-    ":dartdevc_sdk",
     ":dartdevc_kernel_sdk",
+    ":dartdevc_sdk",
     ":dartdevc_test_pkg",
     "../../sdk:create_sdk",
   ]
@@ -223,8 +221,8 @@ group("dartdevc_test") {
 # building the Dart VM and create_sdk.
 group("dartdevc_test_local") {
   deps = [
-    ":dartdevc_sdk",
     ":dartdevc_kernel_sdk",
+    ":dartdevc_sdk",
     ":dartdevc_test_pkg",
   ]
 }
@@ -244,10 +242,10 @@ create_timestamp_file("dartdevc_sdk_patch_stamp") {
 prebuilt_dart_action("dartdevc_test_pkg") {
   deps = [
     ":dartdevc_files_stamp",
-    ":dartdevc_sdk",
     ":dartdevc_kernel_sdk",
-    ":dartdevc_kernel_sdk_outline",
     ":dartdevc_kernel_sdk_libraries_json",
+    ":dartdevc_kernel_sdk_outline",
+    ":dartdevc_sdk",
     "../../pkg:pkg_files_stamp",
   ]
 
@@ -319,9 +317,9 @@ prebuilt_dart_action("dartdevc_test_pkg") {
 
 prebuilt_dart_action("dartdevc_kernel_sdk_outline") {
   deps = [
-    "../../pkg:pkg_files_stamp",
     ":dartdevc_files_stamp",
     ":dartdevc_sdk_patch_stamp",
+    "../../pkg:pkg_files_stamp",
   ]
 
   inputs = [
@@ -349,7 +347,7 @@ prebuilt_dart_action("dartdevc_kernel_sdk_outline") {
     "--output",
     rebase_path(sdk_dill),
     "--source",
-    "dart:core"
+    "dart:core",
   ]
 }
 
@@ -365,9 +363,9 @@ copy("dartdevc_kernel_sdk_libraries_json") {
 # Compiles the DDC SDK's kernel summary and JS code.
 prebuilt_dart_action("dartdevc_kernel_sdk") {
   deps = [
-    "../../pkg:pkg_files_stamp",
     ":dartdevc_files_stamp",
     ":dartdevc_sdk_patch_stamp",
+    "../../pkg:pkg_files_stamp",
   ]
 
   inputs = [

utils/kernel-service/BUILD.gn

@@ -10,7 +10,6 @@ import("../application_snapshot.gni")
 group("kernel-service") {
   if (create_kernel_service_snapshot) {
     deps = [
-      # TODO(rmacnak): Link this into 'dart'.
       ":copy_kernel-service_snapshot",
     ]
   } else {
@@ -20,13 +19,8 @@ group("kernel-service") {
   }
 }
 
-# TODO: Switch this to use kernel based app-jit snapshot
-# when we are ready to switch to the kernel based core snapshots.
 kernel_application_snapshot("kernel-service_snapshot") {
-  main_dart = "$root_gen_dir/kernel_service.dill"
-  deps = [
-    ":kernel_service_dill",
-  ]
+  main_dart = "../../pkg/vm/bin/kernel_service.dart"
   training_args = [
     "--train",
     "file:///" + rebase_path("../../pkg/compiler/lib/src/dart2js.dart"),