icuSources/test/depstest/depstest.py

   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
  15 This probably works only on Linux.
  16
  17 The exit code is 0 if everything is fine, 1 for errors, 2 for only warnings.
  18
  19 Sample invocation with an in-source build:
  20   ~/icu/icu4c/source/test/depstest$ ./depstest.py ../../
  21
  22 Sample invocation with an out-of-source build:
  23   ~/icu/icu4c/source/test/depstest$ ./depstest.py ~/build/
  24 """
  25
  26 from __future__ import print_function
  27
  28 __author__ = "Markus W. Scherer"
  29
  30 import glob
  31 import os.path
  32 import subprocess
  33 import sys
  34
  35 import 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
  48 def 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
  57 def _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
  99 def _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?
 107 allowed_errors = (
 108   ("common/umutex.o", "std::__throw_system_error(int)"),
 109   ("common/umutex.o", "std::uncaught_exception()"),
 110   ("common/unifiedcache.o", "std::__throw_system_error(int)"),
 111 )
 112
 113 def _Resolve(name, parents):
 114   global _ignored_symbols, _obj_files, _symbols_to_files, _return_value
 115   item = dependencies.items[name]
 116   item_type = item["type"]
 117   if name in parents:
 118     sys.exit("Error: %s %s has a circular dependency on itself: %s" %
 119              (item_type, name, parents))
 120   # Check if already cached.
 121   exports = item.get("exports")
 122   if exports != None: return item
 123   # Calculcate recursively.
 124   parents.append(name)
 125   imports = set()
 126   exports = set()
 127   system_symbols = item.get("system_symbols")
 128   if system_symbols == None: system_symbols = item["system_symbols"] = set()
 129   files = item.get("files")
 130   if files:
 131     for file_name in files:
 132       obj_file = _obj_files[file_name]
 133       imports |= obj_file["imports"]
 134       exports |= obj_file["exports"]
 135   imports -= exports | _ignored_symbols
 136   deps = item.get("deps")
 137   if deps:
 138     for dep in deps:
 139       dep_item = _Resolve(dep, parents)
 140       # Detect whether this item needs to depend on dep,
 141       # except when this item has no files, that is, when it is just
 142       # a deliberate umbrella group or library.
 143       dep_exports = dep_item["exports"]
 144       dep_system_symbols = dep_item["system_symbols"]
 145       if files and imports.isdisjoint(dep_exports) and imports.isdisjoint(dep_system_symbols):
 146         print("Info:  %s %s  does not need to depend on  %s\n" % (item_type, name, dep))
 147       # We always include the dependency's exports, even if we do not need them
 148       # to satisfy local imports.
 149       exports |= dep_exports
 150       system_symbols |= dep_system_symbols
 151   item["exports"] = exports
 152   item["system_symbols"] = system_symbols
 153   imports -= exports | system_symbols
 154   for symbol in imports:
 155     for file_name in files:
 156       if (file_name, symbol) in allowed_errors:
 157          sys.stderr.write("Info:  ignoring %s imports %s\n\n" % (file_name, symbol))
 158          continue
 159       if symbol in _obj_files[file_name]["imports"]:
 160         neededFile = _symbols_to_files.get(symbol)
 161         if neededFile in dependencies.file_to_item:
 162           neededItem = "but %s does not depend on %s (for %s)" % (name, dependencies.file_to_item[neededFile], neededFile)
 163         else:
 164           neededItem = "- is this a new system symbol?"
 165         sys.stderr.write("Error: in %s %s: %s imports %s %s\n" %
 166                          (item_type, name, file_name, symbol, neededItem))
 167         _return_value = 1
 168   del parents[-1]
 169   return item
 170
 171 def Process(root_path):
 172   """Loads dependencies.txt, reads the libraries' .o files, and processes them.
 173
 174   Modifies dependencies.items: Recursively builds each item's system_symbols and exports.
 175   """
 176   global _ignored_symbols, _obj_files, _return_value
 177   global _virtual_classes, _weak_destructors
 178   dependencies.Load()
 179   for name_and_item in iteritems(dependencies.items):
 180     name = name_and_item[0]
 181     item = name_and_item[1]
 182     system_symbols = item.get("system_symbols")
 183     if system_symbols:
 184       for symbol in system_symbols:
 185         _symbols_to_files[symbol] = name
 186   for library_name in dependencies.libraries:
 187     _ReadLibrary(root_path, library_name)
 188   o_files_set = set(_obj_files.keys())
 189   files_missing_from_deps = o_files_set - dependencies.files
 190   files_missing_from_build = dependencies.files - o_files_set
 191   if files_missing_from_deps:
 192     sys.stderr.write("Error: files missing from dependencies.txt:\n%s\n" %
 193                      sorted(files_missing_from_deps))
 194     _return_value = 1
 195   if files_missing_from_build:
 196     sys.stderr.write("Error: files in dependencies.txt but not built:\n%s\n" %
 197                      sorted(files_missing_from_build))
 198     _return_value = 1
 199   if not _return_value:
 200     for library_name in dependencies.libraries:
 201       _Resolve(library_name, [])
 202   if not _return_value:
 203     virtual_classes_with_weak_destructors = _virtual_classes & _weak_destructors
 204     if virtual_classes_with_weak_destructors:
 205       sys.stderr.write("Error: Some classes have virtual methods, and "
 206                        "an implicit or inline destructor "
 207                        "(see ICU ticket #8454 for details):\n%s\n" %
 208                        sorted(virtual_classes_with_weak_destructors))
 209       _return_value = 1
 210
 211 def main():
 212   global _return_value
 213   if len(sys.argv) <= 1:
 214     sys.exit(("Command line error: " +
 215              "need one argument with the root path to the built ICU libraries/*.o files."))
 216   Process(sys.argv[1])
 217   if _ignored_symbols:
 218     print("Info: ignored symbols:\n%s" % sorted(_ignored_symbols))
 219   if not _return_value:
 220     print("OK: Specified and actual dependencies match.")
 221   else:
 222     print("Error: There were errors, please fix them and re-run. Processing may have terminated abnormally.")
 223   return _return_value
 224
 225 if __name__ == "__main__":
 226   sys.exit(main())