Add Kernel Isolate

runtime/bin/main.cc

Index: runtime/bin/main.cc
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index 0adf4ac957f8fd899344dea432b59a09f37366df..72cb321c91a231b99c3a3256c2368891dbffc180 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -61,6 +61,10 @@ enum SnapshotKind {
 };
 static SnapshotKind gen_snapshot_kind = kNone;
 
+static bool use_dart_frontend = false;
+
+static const char* frontend_filename = NULL;
+
 // Value of the --package-root flag.
 // (This pointer points into an argv buffer and does not need to be
 // free'd.)
@@ -324,6 +328,18 @@ static bool ProcessParseAllOption(const char* arg,
 }
 
 
+static bool ProcessFrontendOption(const char* filename,
+                                  CommandLineOptions* vm_options) {
+  ASSERT(filename != NULL);
+  if (filename[0] == '\0') {
+    return false;
+  }
+  use_dart_frontend = true;
+  frontend_filename = filename;
+  return true;
+}
+
+
 static bool ProcessUseBlobsOption(const char* arg,
                                   CommandLineOptions* vm_options) {
   ASSERT(arg != NULL);
@@ -540,6 +556,7 @@ static struct {
     // VM specific options to the standalone dart program.
     {"--compile_all", ProcessCompileAllOption},
     {"--parse_all", ProcessParseAllOption},
+    {"--dfe=", ProcessFrontendOption},
     {"--enable-vm-service", ProcessEnableVmServiceOption},
     {"--disable-service-origin-check", ProcessDisableServiceOriginCheckOption},
     {"--observe", ProcessObserveOption},
@@ -791,6 +808,16 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
       (strcmp(script_uri, DART_VM_SERVICE_ISOLATE_NAME) == 0)) {
     return NULL;
   }
+  if (strcmp(script_uri, DART_KERNEL_ISOLATE_NAME) == 0) {
+    if (!use_dart_frontend) {
+      *error = strdup("Kernel isolate not supported.");
+      return NULL;
+    } else {
+      if (packages_config == NULL) {
+        packages_config = commandline_packages_file;
+      }
+    }
+  }
 
   // If the script is a Kernel binary, then we will try to bootstrap from the
   // script.
@@ -870,6 +897,10 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
     CHECK_RESULT(result);
   }
 
+  if (Dart_IsKernelIsolate(isolate)) {
+    script_uri = frontend_filename;
+  }
+
   // Setup package root if specified.
   result = DartUtils::SetupPackageRoot(package_root, packages_config);
   CHECK_RESULT(result);
@@ -877,6 +908,13 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
   result = Dart_SetEnvironmentCallback(EnvironmentCallback);
   CHECK_RESULT(result);
 
+  if (!Dart_IsKernelIsolate(isolate) && use_dart_frontend) {
+    Log::Print("Waiting for Kernel isolate to load.\n");

[Cutch, 2016/12/01 19:47:23]

we shouldn't print to stdout here because it will interfere with the program's
output.

[hausner, 2016/12/03 01:29:00]

Done.

+    // This must be the main script to be loaded. Wait for Kernel isolate
+    // to finish initialization.
+    Dart_ServiceWaitForKernelPort();

[siva, 2016/12/02 00:39:23]

If this returns with ILLEGAL_PORT we should return NULL right so that it will be
processed as an error.

[hausner, 2016/12/03 01:29:00]

If this return ILLEGAL_PORT, e.g. because there was an error in loading the
front end, then we currently just fall back to the C front end. Maybe that just
silently ignores potential errors in the dart front end. 

Added checks as you proposed.

+  }
+
   if (run_app_snapshot) {
     result = DartUtils::SetupIOLibrary(script_uri);
     CHECK_RESULT(result);