Add a script to generate the Java-class-to-objc-header mapping for J2ObjC. Previously the mapping is generated directly by J2ObjC through j2objc_wrapper.py.
RELNOTES:None.
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PiperOrigin-RevId: 151138711
MOS_MIGRATED_REVID=151138711
diff --git a/tools/j2objc/j2objc_header_map.py b/tools/j2objc/j2objc_header_map.py
new file mode 100644
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+++ b/tools/j2objc/j2objc_header_map.py
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+#!/usr/bin/python2.7
+
+# Copyright 2017 The Bazel 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.
+
+"""A script to generate Java class to ObjC header mapping for J2ObjC.
+
+This script generates a text file containing mapping between top-level Java
+classes to associated ObjC headers, generated by J2ObjC.
+
+The mapping file is used by dependent J2ObjC transpilation actions to locate
+the correct header import paths for dependent Java classes.
+
+Inside the script, we read the Java source files and source jars of a single
+Java rule, and parse out the package names from the package statements, using
+regular expression matching.
+
+Note that we cannot guarantee 100% correctness by using just regular expression,
+but it should be good enough. This allows us to avoid doing any further complex
+parsing of the source files and keep the script light-weight without other
+dependencies. In the future, we can consider implementing a simple Java lexer
+here that correctly parses the package statements out of Java files.
+"""
+
+import argparse
+import os
+import re
+import zipfile
+
+_PACKAGE_RE = re.compile(r'(package)\s+([\w\.]+);')
+
+
+def _get_file_map_entry(java_file_path, java_file):
+ """Returns the top-level Java class and header file path tuple.
+
+ Args:
+ java_file_path: The file path of the source Java file.
+ java_file: The actual file of the source java file.
+ Returns:
+ A tuple containing top-level Java class and associated header file path. Or
+ None if no package statement exists in the source file.
+ """
+ for line in java_file:
+ stripped_line = line.strip()
+ package_statement = _PACKAGE_RE.search(stripped_line)
+
+ # We identified a potential package statement.
+ if package_statement:
+ preceding_characters = stripped_line[0:package_statement.start(1)]
+ # We have preceding characters before the package statement. We need to
+ # look further into them.
+ if preceding_characters:
+ # Skip comment line.
+ if preceding_characters.startswith('//'):
+ continue
+
+ # Preceding characters also must end with a space, represent an end
+ # of comment, or end of a statement.
+ # Otherwise, we skip the current line.
+ if not (preceding_characters[len(preceding_characters) - 1].isspace() or
+ preceding_characters.endswith(';') or
+ preceding_characters.endswith('*/')):
+ continue
+ package_name = package_statement.group(2)
+ class_name = os.path.splitext(os.path.basename(java_file_path))[0]
+ header_file = os.path.splitext(java_file_path)[0] + '.h'
+ return (package_name + '.' + class_name, header_file)
+ return None
+
+
+def main():
+ parser = argparse.ArgumentParser(fromfile_prefix_chars='@')
+ parser.add_argument(
+ '--source_files',
+ required=False,
+ help='The source files')
+ parser.add_argument(
+ '--source_jars',
+ required=False,
+ help='The source jars.')
+ parser.add_argument(
+ '--output_mapping_file',
+ required=False,
+ help='The output mapping file')
+
+ args, _ = parser.parse_known_args()
+ class_to_header_map = dict()
+
+ # Process the source files.
+ if args.source_files:
+ source_files = args.source_files.split(',')
+ for source_file in source_files:
+ with open(source_file, 'r') as f:
+ entry = _get_file_map_entry(source_file, f)
+ if entry:
+ class_to_header_map[entry[0]] = entry[1]
+
+ # Process the source jars.
+ if args.source_jars:
+ source_jars = args.source_jars.split(',')
+ for source_jar in source_jars:
+ with zipfile.ZipFile(source_jar, 'r') as jar:
+ for jar_entry in jar.namelist():
+ if jar_entry.endswith('.java'):
+ with jar.open(jar_entry) as jar_entry_file:
+ entry = _get_file_map_entry(jar_entry, jar_entry_file)
+ if entry:
+ class_to_header_map[entry[0]] = entry[1]
+
+ # Generate the output header mapping file.
+ if args.output_mapping_file:
+ with open(args.output_mapping_file, 'w') as output_mapping_file:
+ for class_name in sorted(class_to_header_map):
+ header_path = class_to_header_map[class_name]
+ output_mapping_file.write(class_name + '=' + header_path + '\n')
+
+if __name__ == '__main__':
+ main()
