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1#! /usr/bin/python -B
2# -*- coding: utf-8 -*-
3#
4# Copyright (C) 2016 and later: Unicode, Inc. and others.
5# License & terms of use: http://www.unicode.org/copyright.html
6# Copyright (C) 2011-2015, International Business Machines
7# Corporation and others. All Rights Reserved.
8#
9# file name: depstest.py
10#
11# created on: 2011may24
12
13"""ICU dependency tester.
14
15This probably works only on Linux.
16
17The exit code is 0 if everything is fine, 1 for errors, 2 for only warnings.
18
19Sample invocation with an in-source build:
20  ~/icu/icu4c/source/test/depstest$ ./depstest.py ../../
21
22Sample invocation with an out-of-source build:
23  ~/icu/icu4c/source/test/depstest$ ./depstest.py ~/build/
24"""
25
26from __future__ import print_function
27
28__author__ = "Markus W. Scherer"
29
30import glob
31import os.path
32import subprocess
33import sys
34
35import dependencies
36
37_ignored_symbols = set()
38_obj_files = {}
39_symbols_to_files = {}
40_return_value = 0
41
42# Classes with vtables (and thus virtual methods).
43_virtual_classes = set()
44# Classes with weakly defined destructors.
45# nm shows a symbol class of "W" rather than "T".
46_weak_destructors = set()
47
48def iteritems(items):
49  """Python 2/3-compatible iteritems"""
50  try:
51    for v in items.iteritems():
52      yield v
53  except AttributeError:
54    for v in items.items():
55      yield v
56
57def _ReadObjFile(root_path, library_name, obj_name):
58  global _ignored_symbols, _obj_files, _symbols_to_files
59  global _virtual_classes, _weak_destructors
60  lib_obj_name = library_name + "/" + obj_name
61  if lib_obj_name in _obj_files:
62    print("Warning: duplicate .o file " + lib_obj_name)
63    _return_value = 2
64    return
65
66  path = os.path.join(root_path, library_name, obj_name)
67  nm_result = subprocess.Popen(["nm", "--demangle", "--format=sysv",
68                                "--extern-only", "--no-sort", path],
69                               stdout=subprocess.PIPE).communicate()[0]
70  obj_imports = set()
71  obj_exports = set()
72  for line in nm_result.splitlines():
73    fields = line.decode().split("|")
74    if len(fields) == 1: continue
75    name = fields[0].strip()
76    # Ignore symbols like '__cxa_pure_virtual',
77    # 'vtable for __cxxabiv1::__si_class_type_info' or
78    # 'DW.ref.__gxx_personality_v0'.
79    # '__dso_handle' belongs to __cxa_atexit().
80    if (name.startswith("__cxa") or "__cxxabi" in name or "__gxx" in name or
81        name == "__dso_handle"):
82      _ignored_symbols.add(name)
83      continue
84    type = fields[2].strip()
85    if type == "U":
86      obj_imports.add(name)
87    else:
88      obj_exports.add(name)
89      _symbols_to_files[name] = lib_obj_name
90      # Is this a vtable? E.g., "vtable for icu_49::ByteSink".
91      if name.startswith("vtable for icu"):
92        _virtual_classes.add(name[name.index("::") + 2:])
93      # Is this a destructor? E.g., "icu_49::ByteSink::~ByteSink()".
94      index = name.find("::~")
95      if index >= 0 and type == "W":
96        _weak_destructors.add(name[index + 3:name.index("(", index)])
97  _obj_files[lib_obj_name] = {"imports": obj_imports, "exports": obj_exports}
98
99def _ReadLibrary(root_path, library_name):
100  obj_paths = glob.glob(os.path.join(root_path, library_name, "*.o"))
101  for path in obj_paths:
102    _ReadObjFile(root_path, library_name, os.path.basename(path))
103
104# Dependencies that would otherwise be errors, but that are to be allowed
105# in a limited (not transitive) context.  List of (file_name, symbol)
106# TODO: Move this data to dependencies.txt?
107allowed_errors = (
108  ("common/umutex.o", "std::__throw_system_error(int)"),
109  ("common/umutex.o", "std::uncaught_exception()"),
110  ("common/umutex.o", "std::__once_callable"),
111  ("common/umutex.o", "std::__once_call"),
112  ("common/umutex.o", "__once_proxy"),
113  ("common/umutex.o", "__tls_get_addr"),
114  ("common/unifiedcache.o", "std::__throw_system_error(int)"),
115)
116
117def _Resolve(name, parents):
118  global _ignored_symbols, _obj_files, _symbols_to_files, _return_value
119  item = dependencies.items[name]
120  item_type = item["type"]
121  if name in parents:
122    sys.exit("Error: %s %s has a circular dependency on itself: %s" %
123             (item_type, name, parents))
124  # Check if already cached.
125  exports = item.get("exports")
126  if exports != None: return item
127  # Calculcate recursively.
128  parents.append(name)
129  imports = set()
130  exports = set()
131  system_symbols = item.get("system_symbols")
132  if system_symbols == None: system_symbols = item["system_symbols"] = set()
133  files = item.get("files")
134  if files:
135    for file_name in files:
136      obj_file = _obj_files[file_name]
137      imports |= obj_file["imports"]
138      exports |= obj_file["exports"]
139  imports -= exports | _ignored_symbols
140  deps = item.get("deps")
141  if deps:
142    for dep in deps:
143      dep_item = _Resolve(dep, parents)
144      # Detect whether this item needs to depend on dep,
145      # except when this item has no files, that is, when it is just
146      # a deliberate umbrella group or library.
147      dep_exports = dep_item["exports"]
148      dep_system_symbols = dep_item["system_symbols"]
149      if files and imports.isdisjoint(dep_exports) and imports.isdisjoint(dep_system_symbols):
150        print("Info:  %s %s  does not need to depend on  %s\n" % (item_type, name, dep))
151      # We always include the dependency's exports, even if we do not need them
152      # to satisfy local imports.
153      exports |= dep_exports
154      system_symbols |= dep_system_symbols
155  item["exports"] = exports
156  item["system_symbols"] = system_symbols
157  imports -= exports | system_symbols
158  for symbol in imports:
159    for file_name in files:
160      if (file_name, symbol) in allowed_errors:
161         sys.stderr.write("Info:  ignoring %s imports %s\n\n" % (file_name, symbol))
162         continue
163      if symbol in _obj_files[file_name]["imports"]:
164        neededFile = _symbols_to_files.get(symbol)
165        if neededFile in dependencies.file_to_item:
166          neededItem = "but %s does not depend on %s (for %s)" % (name, dependencies.file_to_item[neededFile], neededFile)
167        else:
168          neededItem = "- is this a new system symbol?"
169        sys.stderr.write("Error: in %s %s: %s imports %s %s\n" %
170                         (item_type, name, file_name, symbol, neededItem))
171        _return_value = 1
172  del parents[-1]
173  return item
174
175def Process(root_path):
176  """Loads dependencies.txt, reads the libraries' .o files, and processes them.
177
178  Modifies dependencies.items: Recursively builds each item's system_symbols and exports.
179  """
180  global _ignored_symbols, _obj_files, _return_value
181  global _virtual_classes, _weak_destructors
182  dependencies.Load()
183  for name_and_item in iteritems(dependencies.items):
184    name = name_and_item[0]
185    item = name_and_item[1]
186    system_symbols = item.get("system_symbols")
187    if system_symbols:
188      for symbol in system_symbols:
189        _symbols_to_files[symbol] = name
190  for library_name in dependencies.libraries:
191    _ReadLibrary(root_path, library_name)
192  o_files_set = set(_obj_files.keys())
193  files_missing_from_deps = o_files_set - dependencies.files
194  files_missing_from_build = dependencies.files - o_files_set
195  if files_missing_from_deps:
196    sys.stderr.write("Error: files missing from dependencies.txt:\n%s\n" %
197                     sorted(files_missing_from_deps))
198    _return_value = 1
199  if files_missing_from_build:
200    sys.stderr.write("Error: files in dependencies.txt but not built:\n%s\n" %
201                     sorted(files_missing_from_build))
202    _return_value = 1
203  if not _return_value:
204    for library_name in dependencies.libraries:
205      _Resolve(library_name, [])
206  if not _return_value:
207    virtual_classes_with_weak_destructors = _virtual_classes & _weak_destructors
208    if virtual_classes_with_weak_destructors:
209      sys.stderr.write("Error: Some classes have virtual methods, and "
210                       "an implicit or inline destructor "
211                       "(see ICU ticket #8454 for details):\n%s\n" %
212                       sorted(virtual_classes_with_weak_destructors))
213      _return_value = 1
214
215def main():
216  global _return_value
217  if len(sys.argv) <= 1:
218    sys.exit(("Command line error: " +
219             "need one argument with the root path to the built ICU libraries/*.o files."))
220  Process(sys.argv[1])
221  if _ignored_symbols:
222    print("Info: ignored symbols:\n%s" % sorted(_ignored_symbols))
223  if not _return_value:
224    print("OK: Specified and actual dependencies match.")
225  else:
226    print("Error: There were errors, please fix them and re-run. Processing may have terminated abnormally.")
227  return _return_value
228
229if __name__ == "__main__":
230  sys.exit(main())
231