[libfuzzer] a utility to zip all source files referenced by a binary

Will be used by libfuzzer bots to send sources to coverage tool.

BUG=539572

Review-Url: https://codereview.chromium.org/2026943002
Cr-Commit-Position: refs/heads/master@{#397301}

testing/libfuzzer/zip_sources.py

@@ -0,0 +1,63 @@
+#!/usr/bin/python2
+#
+# Copyright 2016 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.
+
+"""Archive all source files that are references in binary debug info.
+
+Invoked by libfuzzer buildbots. Executes llvm-dwarfdump to parse debug info.
+"""
+
+from __future__ import print_function
+
+import argparse
+import os
+import re
+import subprocess
+import zipfile
+
+compile_unit_re = re.compile('.*DW_TAG_compile_unit.*')
+at_name_re = re.compile('.*DW_AT_name.*debug_str\[.*\] = "(.*)".*')
+
+
+def main():
+  parser = argparse.ArgumentParser(description="Zip binary sources.")
+  parser.add_argument('--binary', required=True,
+          help='binary file to read')
+  parser.add_argument('--workdir', required=True,
+          help='working directory to use to resolve relative paths')
+  parser.add_argument('--output', required=True,
+          help='output zip file name')
+  parser.add_argument('--llvm-dwarfdump', required=False,
+          default='llvm-dwarfdump', help='path to llvm-dwarfdump utility')
+  args = parser.parse_args()
+
+  # Dump .debug_info section.
+  out = subprocess.check_output(
+          [args.llvm_dwarfdump, '-debug-dump=info', args.binary])
+
+  looking_for_unit = True
+  compile_units = set()
+
+  # Look for DW_AT_name within DW_TAG_compile_unit
+  for line in out.splitlines():
+    if looking_for_unit and compile_unit_re.match(line):
+      looking_for_unit = False
+    elif not looking_for_unit:
+      match = at_name_re.match(line)
+      if match:
+        compile_units.add(match.group(1))
+        looking_for_unit = True
+
+  # Zip sources.
+  with zipfile.ZipFile(args.output, 'w') as z:
+    for compile_unit in sorted(compile_units):
+      src_file = os.path.abspath(os.path.join(args.workdir, compile_unit))
+      print(src_file)
+      z.write(src_file, compile_unit)
+
+
+if __name__ == '__main__':
+  main()
+