Introduce dartanalyze into our build.

mojo/public/tools/dart_analyze.py

+#!/usr/bin/python
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# To integrate dartanalyze with out build system, we take an input file, run
+# the analyzer on it, and write a stamp file if it passed.
+#
+# The first argument to this script is a reference to this build's gen
+# directory. The second is the stamp file to touch if we succeed. The rest are
+# passed to the analyzer verbatim.
+#
+# While it'd be nice to get a list of generated *.mojom.dart files from the gn
+# file, AFAICT, that's impossible because the targets are in different
+# files. Besides, this won't deal with dependencies correctly. So instead, we
+# search the entire gen directory for *.mojom.dart files, and add a url-mapping
+# for each found mojom.dart in our build.

[Elliot Glaysher, 2015/02/24 22:41:53]

I suspect that this is what is making it slow, but I don't have any alternatives
to offer. Thoughts?

[zra, 2015/02/24 23:04:39]

Can you just pass main.dart to the analyzer? Does it not chase down all imports
for you? Would that not be sufficient somehow?

If I understand correctly, you can pass a --package-root argument to the
analyzer to tell it how to resolve package: imports.

[Elliot Glaysher, 2015/02/24 23:47:48]

Using --package-root works.

However, it doesn't solve the bulk of the problem. Running the analyzer goes
from four seconds to three.

+
+import os
+import subprocess
+import sys
+import re
+
+_ANALYZING_PATTERN = re.compile(r'^Analyzing \[')
+_FINAL_REPORT_PATTERN = re.compile(r'^[0-9]+ errors and [0-9]+ warnings found.')
+
+_NATIVE_ERROR_PATTERN = re.compile(
+  r'^\[error\] Native functions can only be declared in the SDK and code that '
+  r'is loaded through native extensions')
+_WARNING_PATTERN = re.compile(r'^\[warning\]')
+_THAT_ONE_BROKEN_CLOSE_IN_WEB_SOCKETS_PATTERN = re.compile(
+  r'^\[error\] The name \'close\' is already defined')
+
+def main(args):
+  cmd = [
+    "../../third_party/dart-sdk/dart-sdk/bin/dartanalyzer",
+  ]
+
+  gen_dir = args.pop(0)
+  gen_dir_len = len(gen_dir) + 1
+  stamp_file = args.pop(0)
+  cmd.extend(args)
+
+  # Recursively walk gen_dir looking for mojom files
+  mojom_dart_files = []
+  for root, _, files in os.walk(gen_dir):
+    for name in files:
+      if name.endswith(".mojom.dart"):
+        mojom_dart_files.append(os.path.join(root, name))
+
+  # For every file found, add the proper package mappings.
+  for file_path in mojom_dart_files:
+    dart_name = file_path[gen_dir_len:]
+    cmd.append("--url-mapping=package:%s,%s" % (dart_name, file_path))

[zra, 2015/02/24 23:04:40]

We should either: 1) use the --package-root flag, or 2) put the package: imports
in the packages/ subdirectory of the app, which is the default if it is not set,
and then not set the package root in the embedder.

+
+  passed = True
+  try:
+    subprocess.check_output(cmd, shell=False, stderr=subprocess.STDOUT)
+  except subprocess.CalledProcessError as e:
+    # Perform post processing on the output. Filter out non-error messages and
+    # known problem patterns that we're working on.
+    raw_lines = e.output.split('\n')
+    # Remove the last empty line
+    raw_lines.pop()
+    filtered_lines = [i for i in raw_lines if (
+      not re.match(_ANALYZING_PATTERN, i) and
+      not re.match(_FINAL_REPORT_PATTERN, i) and
+      # TODO(erg): Remove the rest of these as fixes land:
+      not re.match(_WARNING_PATTERN, i) and
+      not re.match(_NATIVE_ERROR_PATTERN, i) and
+      not re.match(_THAT_ONE_BROKEN_CLOSE_IN_WEB_SOCKETS_PATTERN, i))]
+    for line in filtered_lines:
+      passed = False
+      print >> sys.stderr, line
+
+  if passed:
+    # We passed cleanly, so touch the stamp file so that we don't run again.
+    with open(stamp_file, 'a'):
+      os.utime(stamp_file, None)
+    return 0
+  else:
+    return -2
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))