Introduce script to collect deprecation statistics

Example:

~/v8$ tools/deprecation_stats.py include/v8.h --before=2018-10-01
Marked as V8_DEPRECATE_SOON: 21
     556 : 2017-11-15 11:00:49 : V8_INLINE void MarkIndependent()
     568 : 2017-11-15 11:00:49 : V8_INLINE bool IsIndependent() const
    2404 : 2018-09-24 13:05:31 : V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(Local<Context> context) const
    2421 : 2015-03-09 10:49:09 : Local<Number> ToNumber(Isolate* isolate) const
    2423 : 2015-03-09 10:49:09 : Local<String> ToString(Isolate* isolate) const
  <...>
    3416 : 2015-03-09 10:49:09 : Local<Array> GetOwnPropertyNames()
    3516 : 2015-03-09 10:49:09 : bool HasRealNamedProperty(Local<String> key)
    3533 : 2015-03-09 10:49:09 : bool HasRealIndexedProperty(uint32_t index)
    3537 : 2015-03-09 10:49:09 : bool HasRealNamedCallbackProperty(Local<String> key)
Marked as V8_DEPRECATED: 9
    1395 : 2018-09-21 23:40:51 : const CachedData* GetCachedData() const
    1853 : 2018-09-20 11:46:49 : MaybeLocal<Value> Parse(Isolate* isolate, Local<String> json_string)
    1953 : 2018-09-20 11:46:49 : std::vector<uint8_t> ReleaseBuffer()
    1977 : 2018-09-20 11:46:49 : void TransferSharedArrayBuffer(uint32_t transfer_id, Local<SharedArrayBuffer> shared_array_buffer)
    5093 : 2018-09-20 11:46:49 : Local<Value> New(Isolate* isolate, double time)
    6355 : 2018-09-20 11:46:49 : size_t max_semi_space_size()
    6361 : 2018-09-20 11:46:49 : void set_max_semi_space_size(size_t limit_in_mb)
    6380 : 2018-09-20 11:46:49 : size_t max_executable_size() const
    6384 : 2018-09-20 11:46:49 : void set_max_executable_size(size_t limit_in_mb)

R=delphick@chromium.org

Change-Id: I723055d30457a4061cdc589a4be09c0279fd5923
Reviewed-on: https://chromium-review.googlesource.com/c/1352307
Commit-Queue: Dan Elphick <delphick@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57906}

tools/deprecation_stats.py

+#!/usr/bin/env python
+# Copyright 2018 the V8 project 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 argparse
+from datetime import datetime
+import re
+import subprocess
+import sys
+
+RE_GITHASH = re.compile(r"^[0-9a-f]{40}")
+RE_AUTHOR_TIME = re.compile(r"^author-time (\d+)$")
+RE_FILENAME = re.compile(r"^filename (.+)$")
+
+def GetBlame(file_path):
+  result = subprocess.check_output(
+      ['git', 'blame', '-t', '--line-porcelain', file_path])
+  line_iter = iter(result.splitlines())
+  blame_list = list()
+  current_blame = None
+  while True:
+    line = next(line_iter, None)
+    if line is None:
+      break
+    if RE_GITHASH.match(line):
+      if current_blame is not None:
+        blame_list.append(current_blame)
+      current_blame = {'time': 0, 'filename': None, 'content': None}
+      continue
+    match = RE_AUTHOR_TIME.match(line)
+    if match:
+      current_blame['time'] = datetime.fromtimestamp(int(match.groups()[0]))
+      continue
+    match = RE_FILENAME.match(line)
+    if match:
+      current_blame['filename'] = match.groups()[0]
+      current_blame['content'] = next(line_iter).strip()
+      continue
+  blame_list.append(current_blame)
+  return blame_list
+
+RE_MACRO_END = re.compile(r"\);");
+RE_DEPRECATE_MACRO = re.compile(r"\(.*?,(.*)\);", re.MULTILINE)
+
+def FilterAndPrint(blame_list, macro, before):
+  index = 0
+  re_macro = re.compile(macro)
+  deprecated = list()
+  while index < len(blame_list):
+    blame = blame_list[index]
+    match = re_macro.search(blame['content'])
+    if match and blame['time'] < before:
+      line = blame['content']
+      time = blame['time']
+      pos = match.end()
+      start = -1
+      parens = 0
+      quotes = 0
+      while True:
+        if pos >= len(line):
+          # extend to next line
+          index = index + 1
+          blame = blame_list[index]
+          if line.endswith(','):
+            # add whitespace when breaking line due to comma
+            line = line + ' '
+          line = line + blame['content']
+        if line[pos] == '(':
+          parens = parens + 1
+        elif line[pos] == ')':
+          parens = parens - 1
+          if parens == 0:
+            break
+        elif line[pos] == '"':
+          quotes = quotes + 1
+        elif line[pos] == ',' and quotes % 2 == 0 and start == -1:
+          start = pos + 1
+        pos = pos + 1
+      deprecated.append([index + 1, time, line[start:pos].strip()])
+    index = index + 1
+  print("Marked as " + macro + ": " + str(len(deprecated)))
+  for linenumber, time, content in deprecated:
+    print(str(linenumber).rjust(8) + " : " + str(time) + " : " + content)
+  return len(deprecated)
+
+def ParseOptions(args):
+  parser = argparse.ArgumentParser(description="Collect deprecation statistics")
+  parser.add_argument("file_path", help="Path to v8.h")
+  parser.add_argument("--before", help="Filter by date")
+  options = parser.parse_args(args)
+  if options.before:
+    options.before = datetime.strptime(options.before, '%Y-%m-%d')
+  else:
+    options.before = datetime.now()
+  return options
+
+def Main(args):
+  options = ParseOptions(args)
+  blame_list = GetBlame(options.file_path)
+  FilterAndPrint(blame_list, "V8_DEPRECATE_SOON", options.before)
+  FilterAndPrint(blame_list, "V8_DEPRECATED", options.before)
+
+if __name__ == "__main__":
+  Main(sys.argv[1:])