Tweak how the pkg files timestamps are created.

The acute problem this solves is that hacking on DDC generates a large
number of files into its gen/ directory. It's enough files that once you
have done that, the SDK no longer builds successfully because it chokes
on them all.

To fix that, instead of using list_files.py, I made a little
list_dart_files.py that is explicitly for Dart files and knows to
exclude gen/ and tests. This also avoids needing the sort of hairy
regexes to match different sets of files.

As far as I can tell, this works, but GYP is pretty mysterious to me,
so let me know if I got something wrong or there is a better way to do
it.

R=whesse@google.com

Review URL: https://codereview.chromium.org/2391863002 .

pkg/pkg_files.gyp

@@ -9,8 +9,8 @@
     # This target lists all the files in pkg and third_party/pkg,
     # and creates the timestamp pkg_files.stamp, which depends on some
     # intermediate helper timestamps.
-    # We split third_party/pkg up into three groups, based on the last
-    # character before .dart at the end of the filename.
+    # We split third_party/pkg up into three groups, based on the first letter
+    # of the package name.
     {
       'target_name': 'pkg_files_stamp',
       'type': 'none',
@@ -19,12 +19,10 @@
           'action_name': 'make_pkg_files_stamp',
           'inputs': [
             '../tools/create_timestamp_file.py',
-            '<!@(["python", "../tools/list_files.py",'
-                '"^(?!.*/test/).*(?<!_test)[.]dart$",'
-                '"."])',
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_1.stamp',
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_2.stamp',
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_3.stamp',
+            '<!@(["python", "../tools/list_dart_files.py", "."])',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_a_k.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_l_r.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_s_z.stamp',
           ],
           'outputs': [
             '<(SHARED_INTERMEDIATE_DIR)/pkg_files.stamp',
@@ -35,15 +33,13 @@
           ],
         },
         {
-          'action_name': 'make_third_party_pkg_files_1_stamp',
+          'action_name': 'make_third_party_pkg_files_a_k_stamp',
           'inputs': [
             '../tools/create_timestamp_file.py',
-            '<!@(["python", "../tools/list_files.py",'
-                '"^(?!.*_test\.dart).*[a-k]\.dart$",'
-                '"../third_party/pkg"])',
+            '<!@(["python", "../tools/list_dart_files.py", "../third_party/pkg", "[a-k].*"])',
           ],
           'outputs': [
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_1.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_a_k.stamp',
           ],
           'action': [
             'python', '../tools/create_timestamp_file.py',
@@ -51,15 +47,13 @@
           ],
         },
         {
-          'action_name': 'make_third_party_pkg_files_2_stamp',
+          'action_name': 'make_third_party_pkg_files_l_r_stamp',
           'inputs': [
             '../tools/create_timestamp_file.py',
-            '<!@(["python", "../tools/list_files.py",'
-                '"^(?!.*_test\.dart).*[l-r]\.dart$",'
-                '"../third_party/pkg"])',
+            '<!@(["python", "../tools/list_dart_files.py", "../third_party/pkg", "[l-r].*"])',
           ],
           'outputs': [
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_2.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_l_r.stamp',
           ],
           'action': [
             'python', '../tools/create_timestamp_file.py',
@@ -67,15 +61,13 @@
           ],
         },
         {
-          'action_name': 'make_third_party_pkg_files_3_stamp',
+          'action_name': 'make_third_party_pkg_files_s_z_stamp',
           'inputs': [
             '../tools/create_timestamp_file.py',
-            '<!@(["python", "../tools/list_files.py",'
-                '"^(?!.*_test\.dart).*[^a-r]\.dart$",'
-                '"../third_party/pkg"])',
+            '<!@(["python", "../tools/list_dart_files.py", "../third_party/pkg", "[s-z].*"])',
           ],
           'outputs': [
-            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_3.stamp',
+            '<(SHARED_INTERMEDIATE_DIR)/third_party_pkg_files_s_z.stamp',
           ],
           'action': [
             'python', '../tools/create_timestamp_file.py',

tools/list_dart_files.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+# Copyright (c) 2016, 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.
+
+"""Tool for listing Dart source files.
+
+Usage:
+  python tools/list_dart_files.py <directory> <root directory pattern>
+"""
+
+import os
+import re
+import sys
+
+
+def main(argv):
+  directory = argv[1]
+
+  pattern = None
+  if len(argv) > 2:
+    pattern = re.compile(argv[2])
+
+  for root, directories, files in os.walk(directory):
+    # We only care about actual source files, not generated code or tests.
+    for skip_dir in ['.git', 'gen', 'test']:
+      if skip_dir in directories:
+        directories.remove(skip_dir)
+
+    # If we are looking at the root directory, filter the immediate
+    # subdirectories by the given pattern.
+    if pattern and root == directory:
+      directories[:] = filter(pattern.match, directories)
+
+    for filename in files:
+      if filename.endswith('.dart') and not filename.endswith('_test.dart'):
+        fullname = os.path.relpath(os.path.join(root, filename))
+        fullname = fullname.replace(os.sep, '/')
+        print fullname
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))