build.py -c closure: Show file name and line number of errors and warnings.

tools/closure_library_jscompiler.py

@@ -0,0 +1,71 @@
+# Copyright 2010 The Closure Library Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS-IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Utility to use the Closure Compiler CLI from Python."""
+
+import distutils.version
+import logging
+import re
+import subprocess
+
+
+# Pulls a version number from the first line of 'java -version'
+# See http://java.sun.com/j2se/versioning_naming.html to learn more about the
+# command's output format.
+_VERSION_REGEX = re.compile('"([0-9][.0-9]*)')
+
+
+def _GetJavaVersion():
+  """Returns the string for the current version of Java installed."""
+  proc = subprocess.Popen(['java', '-version'], stderr=subprocess.PIPE)
+  unused_stdoutdata, stderrdata = proc.communicate()
+  version_line = stderrdata.splitlines()[0]
+  return _VERSION_REGEX.search(version_line).group(1)
+
+
+def Compile(compiler_jar_path, source_paths, flags=None):
+  """Prepares command-line call to Closure Compiler.
+
+  Args:
+    compiler_jar_path: Path to the Closure compiler .jar file.
+    source_paths: Source paths to build, in order.
+    flags: A list of additional flags to pass on to Closure Compiler.
+
+  Returns:
+    The compiled source, as a string, or None if compilation failed.
+  """
+
+  # User friendly version check.
+  if not (distutils.version.LooseVersion(_GetJavaVersion()) >=
+          distutils.version.LooseVersion('1.6')):
+    logging.error('Closure Compiler requires Java 1.6 or higher. '
+                  'Please visit http://www.java.com/getjava')
+    return
+
+  args = ['java', '-jar', compiler_jar_path]
+  for path in source_paths:
+    args += ['--js', path]
+
+  if flags:
+    args += flags
+
+  logging.info('Compiling with the following command: %s', ' '.join(args))
+
+  proc = subprocess.Popen(args, stdout=subprocess.PIPE)
+  stdoutdata, unused_stderrdata = proc.communicate()
+
+  if proc.returncode != 0:
+    return
+
+  return stdoutdata