Skeleton code for running the forthcoming async/await compiler on pub.

sdk/bin/pub

 #!/bin/bash
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
-# Run pub.dart on the Dart VM. This script assumes the Dart SDK's directory
-# structure.
+# Run pub.dart on the Dart VM. This script is only used when running pub from
+# within the Dart source repo. The shipped SDK instead uses "pub_sdk", which is
+# renamed to "pub" when the SDK is built.
 
 function follow_links() {
   file="$1"
   while [ -h "$file" ]; do
     # On Mac OS, readlink -f doesn't work.
     file="$(readlink "$file")"
   done
   echo "$file"
 }
 
@@ skipping 13 matching lines @@
 # Give the VM extra memory for dart2js.
 # TODO(rnystrom): Remove when #8355 is fixed.
 VM_OPTIONS+=("--old_gen_heap_size=1024")
 
 # Allow extra VM options to be passed in through an environment variable.
 if [[ $DART_VM_OPTIONS ]]; then
   read -a OPTIONS <<< "$DART_VM_OPTIONS"
   VM_OPTIONS+=("${OPTIONS[@]}")
 fi
 
-if test -f "$SNAPSHOT"; then
-  # We are running the snapshot in the built SDK.
-  DART="$BIN_DIR/dart"
-  exec "$DART" "${VM_OPTIONS[@]}" "$SNAPSHOT" "$@"
+if [ -z "$DART_CONFIGURATION" ];
+then
+  DART_CONFIGURATION="ReleaseIA32"
+fi
+
+if [[ `uname` == 'Darwin' ]];
+then
+  BUILD_DIR="$SDK_DIR/../xcodebuild/$DART_CONFIGURATION"
 else
-  # We are running pub from source in the development repo.
-  if [ -z "$DART_CONFIGURATION" ];
-  then
-    DART_CONFIGURATION="ReleaseIA32"
-  fi
+  BUILD_DIR="$SDK_DIR/../out/$DART_CONFIGURATION"
+fi
 
-  if [[ `uname` == 'Darwin' ]];
-  then
-    BUILD_DIR="$SDK_DIR/../xcodebuild/$DART_CONFIGURATION"
-  else
-    BUILD_DIR="$SDK_DIR/../out/$DART_CONFIGURATION"
-  fi
+# Use the Dart binary in the built SDK so pub can find the version file next
+# to it.
+DART="$BUILD_DIR/dart-sdk/bin/dart"
+PACKAGES_DIR="$BUILD_DIR/pub_packages/"
 
-  # Use the Dart binary in the built SDK so pub can find the version file next
-  # to it.
-  DART="$BUILD_DIR/dart-sdk/bin/dart"
-  PACKAGES_DIR="$BUILD_DIR/pub_packages/"
+# Compile async/await down to vanilla Dart.
+# TODO(rnystrom): Remove this when #104 is fixed.
+ASYNC_COMPILER="$SDK_DIR/lib/_internal/pub/bin/async_compile.dart"
+"$DART" "--package-root=$PACKAGES_DIR" "$ASYNC_COMPILER" "$BUILD_DIR" --silent
 
-  PUB="$SDK_DIR/lib/_internal/pub/bin/pub.dart"
-
-  exec "$DART" "${VM_OPTIONS[@]}" "--package-root=$PACKAGES_DIR" "$PUB" "$@"
-fi
+# Run the async/await compiled pub.
+PUB="$BUILD_DIR/pub_async/bin/pub.dart"
+exec "$DART" "${VM_OPTIONS[@]}" "--package-root=$PACKAGES_DIR" "$PUB" "$@"