SuperSize: Make ninja parser tolerate rules with no explicit input

Some build rules have a rulename and implicit inputs, but no explicit
inputs. For example:

build libfoo.so: __chrome_android_some_rule | lib_maker.py

Also:

- Add unit tests for the core parser functionality.
- Add a run_tests helper script for quick verification.

Bug: 982334
Change-Id: I7481018ae4ae4ce1bc71a19e73dc241b124bfb6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1715606
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680146}

tools/binary_size/libsupersize/ninja_parser.py

@@ -16,7 +16,8 @@ import re
 # build obj/.../foo.o: cxx gen/.../foo.cc || obj/.../foo.inputdeps.stamp
 # build obj/.../libfoo.a: alink obj/.../a.o obj/.../b.o |
 # build ./libchrome.so ./lib.unstripped/libchrome.so: solink a.o b.o ...
-_REGEX = re.compile(r'build ([^:]+): \w+ (.*?)(?: \||\n|$)')
+# build libmonochrome.so: __chrome_android_libmonochrome___rule | ...
+_REGEX = re.compile(r'build ([^:]+): \w+ (.*?)(?: *\||\n|$)')
 
 
 class _SourceMapper(object):
@@ -65,7 +66,7 @@ class _SourceMapper(object):
 
 def _ParseNinjaPathList(path_list):
   ret = path_list.replace('\\ ', '\b')
-  return [s.replace('\b', ' ') for s in ret.split(' ')]
+  return [s.replace('\b', ' ') for s in ret.split()]
 
 
 def _ParseOneFile(lines, dep_map, elf_path):
@@ -94,6 +95,10 @@ def _ParseOneFile(lines, dep_map, elf_path):
   return sub_ninjas, elf_inputs
 
 
+def ParseOneFileForTest(lines, dep_map, elf_path):
+  return _ParseOneFile(lines, dep_map, elf_path)
+
+
 def Parse(output_directory, elf_path):
   """Parses build.ninja and subninjas.
 

tools/binary_size/libsupersize/ninja_parser_test.py

+#!/usr/bin/env python
+# Copyright 2019 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.
+
+import unittest
+
+import ninja_parser
+
+
+class NinjaParserTest(unittest.TestCase):
+
+  def _ParseOneFile(self, line, lib, expected_inputs, expected_dep_map):
+    """Exercises ninja_parser's ParseOneFile method.
+
+    This allows coverage of most parsing capabilities, without having to
+    synthesize the actual Ninja files expected by the top-level Parse()
+    method.
+    """
+    dep_map = {}
+    _, found_inputs = ninja_parser.ParseOneFileForTest([line], dep_map, lib)
+    self.assertEqual(expected_inputs, found_inputs)
+    self.assertEqual(expected_dep_map, dep_map)
+
+  # These cases cover finding ELF outputs with associated inputs:
+
+  def test_ExplicitDep(self):
+    line = 'build libfoo.so: link a.o'
+    inputs = ['a.o']
+    self._ParseOneFile(line, 'libfoo.so', inputs, {})
+
+  def test_MultipleExplicitDeps(self):
+    line = 'build libfoo.so: link a.o b.o'
+    inputs = ['a.o', 'b.o']
+    self._ParseOneFile(line, 'libfoo.so', inputs, {})
+
+  def test_ExplicitDepWithImplicitDep(self):
+    line = 'build libfoo.so: link a.o | b.o'
+    inputs = ['a.o']
+    self._ParseOneFile(line, 'libfoo.so', inputs, {})
+
+  def test_ExplicitDepWithOrderDep(self):
+    line = 'build libfoo.so: link a.o || b.o'
+    inputs = ['a.o']
+    self._ParseOneFile(line, 'libfoo.so', inputs, {})
+
+  def test_NoExplicitInput(self):
+    line = 'build libfoo.so: custom_link | custom.py'
+    inputs = []
+    self._ParseOneFile(line, 'libfoo.so', inputs, {})
+
+  def test_SpacesInPaths(self):
+    line = 'build libfoo.so: link a\ a.o b\ b.o'
+    inputs = ['a a.o', 'b b.o']
+    self._ParseOneFile(line, 'libfoo.so', inputs, {})
+
+  # These cases cover Object file outputs that update a dependency map:
+
+  def test_ObjectOutputWithExplicitDep(self):
+    line = 'build libfoo.o: cxx a.cc'
+    dep_map = {'libfoo.o': 'a.cc'}
+    self._ParseOneFile(line, 'libfoo.o', None, dep_map)
+
+  def test_ObjectOutputWithExplicitDeps(self):
+    line = 'build libfoo.o: cxx a.cc b.cc'
+    dep_map = {'libfoo.o': 'a.cc b.cc'}
+    self._ParseOneFile(line, 'libfoo.o', None, dep_map)
+
+  def test_ObjectOutputWithOrderDep(self):
+    line = 'build libfoo.o: cxx a.cc || a.inputdeps.stamp'
+    dep_map = {'libfoo.o': 'a.cc'}
+    self._ParseOneFile(line, 'libfoo.o', None, dep_map)
+
+  def test_ObjectOutputWithExplicitDepsAndOrderDep(self):
+    line = 'build libfoo.o: cxx a.cc b.cc || a.inputdeps.stamp'
+    dep_map = {'libfoo.o': 'a.cc b.cc'}
+    self._ParseOneFile(line, 'libfoo.o', None, dep_map)
+
+
+if __name__ == '__main__':
+  unittest.main()

tools/binary_size/libsupersize/run_tests.py

+#!/usr/bin/env vpython
+# Copyright 2019 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.
+
+import logging
+import os
+import sys
+import unittest
+
+if __name__ == '__main__':
+  logging.basicConfig(
+      level=logging.DEBUG if '-v' in sys.argv else logging.WARNING,
+      format='%(levelname)5s %(filename)15s(%(lineno)3d): %(message)s')
+
+  suite = unittest.TestSuite()
+  loader = unittest.TestLoader()
+  suite.addTests(
+      loader.discover(start_dir=os.path.dirname(__file__), pattern='*_test.py'))
+  res = unittest.TextTestRunner(verbosity=2).run(suite)
+  if res.wasSuccessful():
+    sys.exit(0)
+  else:
+    sys.exit(1)