buildtools/wafsamba/symbols.py

   1 # a waf tool to extract symbols from object files or libraries
   2 # using nm, producing a set of exposed defined/undefined symbols
   3
   4 import Utils, Build, subprocess, Logs
   5 from samba_wildcard import fake_build_environment
   6 from samba_utils import *
   7
   8 def symbols_extract(objfiles, dynamic=False):
   9     '''extract symbols from objfile, returning a dictionary containing
  10        the set of undefined and public symbols for each file'''
  11
  12     ret = {}
  13
  14     cmd = ["nm"]
  15     if dynamic:
  16         # needed for some .so files
  17         cmd.append("-D")
  18     cmd.extend(objfiles)
  19
  20     nmpipe = subprocess.Popen(cmd, stdout=subprocess.PIPE).stdout
  21     if len(objfiles) == 1:
  22         filename = objfiles[0]
  23         ret[filename] = { "PUBLIC": set(), "UNDEFINED" : set()}
  24
  25     for line in nmpipe:
  26         line = line.strip()
  27         if line.endswith(':'):
  28             filename = line[:-1]
  29             ret[filename] = { "PUBLIC": set(), "UNDEFINED" : set() }
  30             continue
  31         cols = line.split(" ")
  32         if cols == ['']:
  33             continue
  34         # see if the line starts with an address
  35         if len(cols) == 3:
  36             symbol_type = cols[1]
  37             symbol = cols[2]
  38         else:
  39             symbol_type = cols[0]
  40             symbol = cols[1]
  41         if symbol_type in "BDGTRVWSi":
  42             # its a public symbol
  43             ret[filename]["PUBLIC"].add(symbol)
  44         elif symbol_type in "U":
  45             ret[filename]["UNDEFINED"].add(symbol)
  46
  47     return ret
  48
  49
  50 def real_name(name):
  51     if name.find(".objlist") != -1:
  52         name = name[:-8]
  53     return name
  54
  55
  56 def find_syslib_path(bld, libname, deps):
  57     '''find the path to the syslib we will link against'''
  58     # the strategy is to use the targets that depend on the library, and run ldd
  59     # on it to find the real location of the library that is used
  60
  61     linkpath = deps[0].link_task.outputs[0].abspath(bld.env)
  62
  63     if libname == "python":
  64         libname += bld.env.PYTHON_VERSION
  65
  66     ret = None
  67
  68     lddpipe = subprocess.Popen(['ldd', linkpath], stdout=subprocess.PIPE).stdout
  69     for line in lddpipe:
  70         line = line.strip()
  71         cols = line.split(" ")
  72         if len(cols) < 3 or cols[1] != "=>":
  73             continue
  74         if cols[0].startswith("lib%s." % libname.lower()):
  75             ret = cols[2]
  76         if cols[0].startswith("libc."):
  77             # save this one too
  78             bld.env.libc_path = cols[2]
  79     return ret
  80
  81
  82 def build_symbol_sets(bld, tgt_list):
  83     '''build the public_symbols and undefined_symbols attributes for each target'''
  84
  85     objlist = []  # list of object file
  86     objmap = {}   # map from object filename to target
  87
  88
  89     for t in tgt_list:
  90         t.public_symbols = set()
  91         t.undefined_symbols = set()
  92         for tsk in getattr(t, 'compiled_tasks', []):
  93             for output in tsk.outputs:
  94                 objpath = output.abspath(bld.env)
  95                 objlist.append(objpath)
  96                 objmap[objpath] = t
  97
  98     symbols = symbols_extract(objlist)
  99     for obj in objlist:
 100         t = objmap[obj]
 101         t.public_symbols = t.public_symbols.union(symbols[obj]["PUBLIC"])
 102         t.undefined_symbols = t.undefined_symbols.union(symbols[obj]["UNDEFINED"])
 103
 104     t.undefined_symbols = t.undefined_symbols.difference(t.public_symbols)
 105
 106     # and the reverse map of public symbols to subsystem name
 107     bld.env.symbol_map = {}
 108
 109     for t in tgt_list:
 110         for s in t.public_symbols:
 111             bld.env.symbol_map[s] = real_name(t.sname)
 112
 113     targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
 114
 115     bld.env.public_symbols = {}
 116     for t in tgt_list:
 117         name = real_name(t.sname)
 118         if name in bld.env.public_symbols:
 119             bld.env.public_symbols[name] = bld.env.public_symbols[name].union(t.public_symbols)
 120         else:
 121             bld.env.public_symbols[name] = t.public_symbols
 122         if t.samba_type == 'LIBRARY':
 123             for dep in t.add_objects:
 124                 t2 = bld.name_to_obj(dep, bld.env)
 125                 bld.ASSERT(t2 is not None, "Library '%s' has unknown dependency '%s'" % (name, dep))
 126                 bld.env.public_symbols[name] = bld.env.public_symbols[name].union(t2.public_symbols)
 127
 128
 129 def build_syslib_sets(bld, tgt_list):
 130     '''build the public_symbols for all syslibs'''
 131
 132     # work out what syslibs we depend on, and what targets those are used in
 133     syslibs = {}
 134     objmap = {}
 135     for t in tgt_list:
 136         if getattr(t, 'uselib', []) and t.samba_type in [ 'LIBRARY', 'BINARY', 'PYTHON' ]:
 137             for lib in t.uselib:
 138                 if lib in ['PYEMBED', 'PYEXT']:
 139                     lib = "python"
 140                 if not lib in syslibs:
 141                     syslibs[lib] = []
 142                 syslibs[lib].append(t)
 143
 144     # work out the paths to each syslib
 145     syslib_paths = []
 146     for lib in syslibs:
 147         path = find_syslib_path(bld, lib, syslibs[lib])
 148         if path is None:
 149             Logs.warn("Unable to find syslib path for %s" % lib)
 150         if path is not None:
 151             syslib_paths.append(path)
 152             objmap[path] = lib.lower()
 153
 154     # add in libc
 155     syslib_paths.append(bld.env.libc_path)
 156     objmap[bld.env.libc_path] = 'c'
 157
 158     symbols = symbols_extract(syslib_paths, dynamic=True)
 159
 160     # keep a map of syslib names to public symbols
 161     bld.env.syslib_symbols = {}
 162     for lib in symbols:
 163         bld.env.syslib_symbols[lib] = symbols[lib]["PUBLIC"]
 164
 165     # add to the map of symbols to dependencies
 166     for lib in symbols:
 167         for sym in symbols[lib]["PUBLIC"]:
 168             bld.env.symbol_map[sym] = objmap[lib]
 169
 170     # keep the libc symbols as well, as these are useful for some of the
 171     # sanity checks
 172     bld.env.libc_symbols = symbols[bld.env.libc_path]["PUBLIC"]
 173
 174     # add to the combined map of dependency name to public_symbols
 175     for lib in bld.env.syslib_symbols:
 176         bld.env.public_symbols[objmap[lib]] = bld.env.syslib_symbols[lib]
 177
 178 def build_autodeps(bld, t):
 179     '''build the set of dependencies for a target'''
 180     deps = set()
 181     name = real_name(t.sname)
 182
 183     targets    = LOCAL_CACHE(bld, 'TARGET_TYPE')
 184
 185     for sym in t.undefined_symbols:
 186         if sym in t.public_symbols:
 187             continue
 188         if sym in bld.env.symbol_map:
 189             depname = bld.env.symbol_map[sym]
 190             if depname == name:
 191                 # self dependencies aren't interesting
 192                 continue
 193             if t.in_library == [depname]:
 194                 # no need to depend on the library we are part of
 195                 continue
 196             if depname in ['c', 'python']:
 197                 # these don't go into autodeps
 198                 continue
 199             if targets[depname] in [ 'SYSLIB' ]:
 200                 deps.add(depname)
 201                 continue
 202             t2 = bld.name_to_obj(depname, bld.env)
 203             if len(t2.in_library) != 1:
 204                 deps.add(depname)
 205                 continue
 206             if t2.in_library == t.in_library:
 207                 # if we're part of the same library, we don't need to autodep
 208                 continue
 209             deps.add(t2.in_library[0])
 210     t.autodeps = deps
 211
 212
 213 def build_library_names(bld, tgt_list):
 214     '''add a in_library attribute to all targets that are part of a library'''
 215     for t in tgt_list:
 216         t.in_library = []
 217
 218     for t in tgt_list:
 219         if t.samba_type in [ 'LIBRARY' ]:
 220             for obj in t.samba_deps_extended:
 221                 t2 = bld.name_to_obj(obj, bld.env)
 222                 if t2 and t2.samba_type in [ 'SUBSYSTEM', 'ASN1' ]:
 223                     if not t.sname in t2.in_library:
 224                         t2.in_library.append(t.sname)
 225
 226
 227 def check_library_deps(bld, t):
 228     '''check that all the autodeps that have mutual dependency of this
 229     target are in the same library as the target'''
 230
 231     name = real_name(t.sname)
 232
 233     if len(t.in_library) > 1:
 234         Logs.warn("WARNING: Target '%s' in multiple libraries: %s" % (t.sname, t.in_library))
 235
 236     for dep in t.autodeps:
 237         t2 = bld.name_to_obj(dep, bld.env)
 238         if t2 is None:
 239             continue
 240         for dep2 in t2.autodeps:
 241             if dep2 == name and t.in_library != t2.in_library:
 242                 Logs.warn("WARNING: mutual dependency %s <=> %s" % (name, real_name(t2.sname)))
 243                 Logs.warn("Libraries should match. %s != %s" % (t.in_library, t2.in_library))
 244                 # raise Utils.WafError("illegal mutual dependency")
 245
 246
 247 def check_syslib_collisions(bld, tgt_list):
 248     '''check if a target has any symbol collisions with a syslib
 249
 250     We do not want any code in Samba to use a symbol name from a
 251     system library. The chance of that causing problems is just too
 252     high. Note that libreplace uses a rep_XX approach of renaming
 253     symbols via macros
 254     '''
 255
 256     has_error = False
 257     for t in tgt_list:
 258         for lib in bld.env.syslib_symbols:
 259             common = t.public_symbols.intersection(bld.env.syslib_symbols[lib])
 260             if common:
 261                 Logs.error("ERROR: Target '%s' has symbols '%s' which is also in syslib '%s'" % (t.sname, common, lib))
 262                 has_error = True
 263     if has_error:
 264         raise Utils.WafError("symbols in common with system libraries")
 265
 266
 267 def check_dependencies(bld, t):
 268     '''check for depenencies that should be changed'''
 269
 270     if bld.name_to_obj(t.sname + ".objlist", bld.env):
 271         return
 272
 273     targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
 274
 275     remaining = t.undefined_symbols.copy()
 276     remaining = remaining.difference(t.public_symbols)
 277
 278     sname = real_name(t.sname)
 279
 280     deps = set(t.samba_deps)
 281     for d in t.samba_deps:
 282         if targets[d] in [ 'EMPTY', 'DISABLED', 'SYSLIB' ]:
 283             continue
 284         bld.ASSERT(d in bld.env.public_symbols, "Failed to find symbol list for dependency '%s'" % d)
 285         diff = remaining.intersection(bld.env.public_symbols[d])
 286         if not diff and targets[sname] != 'LIBRARY':
 287             Logs.info("Target '%s' has no dependency on %s" % (sname, d))
 288         else:
 289             remaining = remaining.difference(diff)
 290
 291     t.unsatisfied_symbols = set()
 292     needed = {}
 293     for sym in remaining:
 294         if sym in bld.env.symbol_map:
 295             dep = bld.env.symbol_map[sym]
 296             if not dep in needed:
 297                 needed[dep] = set()
 298             needed[dep].add(sym)
 299         else:
 300             t.unsatisfied_symbols.add(sym)
 301
 302     for dep in needed:
 303         Logs.info("Target '%s' should add dep '%s' for symbols %s" % (sname, dep, " ".join(needed[dep])))
 304
 305
 306
 307 def check_syslib_dependencies(bld, t):
 308     '''check for syslib depenencies'''
 309
 310     if bld.name_to_obj(t.sname + ".objlist", bld.env):
 311         return
 312
 313     sname = real_name(t.sname)
 314
 315     remaining = set()
 316
 317     features = TO_LIST(t.features)
 318     if 'pyembed' in features or 'pyext' in features:
 319         t.unsatisfied_symbols = t.unsatisfied_symbols.difference(bld.env.public_symbols['python'])
 320
 321     needed = {}
 322     for sym in t.unsatisfied_symbols:
 323         if sym in bld.env.symbol_map:
 324             dep = bld.env.symbol_map[sym]
 325             if dep == 'c':
 326                 continue
 327             if not dep in needed:
 328                 needed[dep] = set()
 329             needed[dep].add(sym)
 330         else:
 331             remaining.add(sym)
 332
 333     for dep in needed:
 334         Logs.info("Target '%s' should add syslib dep '%s' for symbols %s" % (sname, dep, " ".join(needed[dep])))
 335
 336     if remaining:
 337         debug("deps: Target '%s' has unsatisfied symbols: %s" % (sname, " ".join(remaining)))
 338
 339
 340
 341 def symbols_symbolcheck(task):
 342     '''check the internal dependency lists'''
 343     bld = task.env.bld
 344     tgt_list = get_tgt_list(bld)
 345
 346     build_symbol_sets(bld, tgt_list)
 347     build_library_names(bld, tgt_list)
 348
 349     for t in tgt_list:
 350         t.autodeps = set()
 351         if getattr(t, 'source', ''):
 352             build_autodeps(bld, t)
 353
 354     for t in tgt_list:
 355         check_dependencies(bld, t)
 356
 357     for t in tgt_list:
 358         check_library_deps(bld, t)
 359
 360 def symbols_syslibcheck(task):
 361     '''check the syslib dependencies'''
 362     bld = task.env.bld
 363     tgt_list = get_tgt_list(bld)
 364
 365     build_syslib_sets(bld, tgt_list)
 366     check_syslib_collisions(bld, tgt_list)
 367
 368     for t in tgt_list:
 369         check_syslib_dependencies(bld, t)
 370
 371
 372 def SYMBOL_CHECK(bld):
 373     '''check our dependency lists'''
 374     if Options.options.SYMBOLCHECK:
 375         bld.SET_BUILD_GROUP('symbolcheck')
 376         task = bld(rule=symbols_symbolcheck, always=True, name='symbol checking')
 377         task.env.bld = bld
 378
 379         bld.SET_BUILD_GROUP('syslibcheck')
 380         task = bld(rule=symbols_syslibcheck, always=True, name='syslib checking')
 381         task.env.bld = bld
 382 Build.BuildContext.SYMBOL_CHECK = SYMBOL_CHECK