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# a waf tool to extract symbols from object files or libraries
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# using nm, producing a set of exposed defined/undefined symbols
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import Utils, Build, subprocess, Logs
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from samba_wildcard import fake_build_environment
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from samba_utils import *
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# these are the data structures used in symbols.py:
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# bld.env.symbol_map : dictionary mapping public symbol names to list of
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# subsystem names where that symbol exists
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# t.in_library : list of libraries that t is in
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# bld.env.public_symbols: set of public symbols for each subsystem
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# bld.env.used_symbols : set of used symbols for each subsystem
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# bld.env.syslib_symbols: dictionary mapping system library name to set of symbols
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# LOCAL_CACHE(bld, 'TARGET_TYPE') : dictionary mapping subsystem name to target type
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def symbols_extract(objfiles, dynamic=False):
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'''extract symbols from objfile, returning a dictionary containing
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the set of undefined and public symbols for each file'''
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# needed for some .so files
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nmpipe = subprocess.Popen(cmd, stdout=subprocess.PIPE).stdout
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if len(objfiles) == 1:
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filename = objfiles[0]
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ret[filename] = { "PUBLIC": set(), "UNDEFINED" : set()}
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if line.endswith(':'):
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ret[filename] = { "PUBLIC": set(), "UNDEFINED" : set() }
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cols = line.split(" ")
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# see if the line starts with an address
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if symbol_type in "BDGTRVWSi":
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ret[filename]["PUBLIC"].add(symbol)
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elif symbol_type in "U":
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ret[filename]["UNDEFINED"].add(symbol)
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if name.find(".objlist") != -1:
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def find_syslib_path(bld, libname, deps):
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'''find the path to the syslib we will link against'''
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# the strategy is to use the targets that depend on the library, and run ldd
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# on it to find the real location of the library that is used
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linkpath = deps[0].link_task.outputs[0].abspath(bld.env)
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if libname == "python":
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libname += bld.env.PYTHON_VERSION
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lddpipe = subprocess.Popen(['ldd', linkpath], stdout=subprocess.PIPE).stdout
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cols = line.split(" ")
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if len(cols) < 3 or cols[1] != "=>":
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if cols[0].startswith("lib%s." % libname.lower()):
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if cols[0].startswith("libc."):
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bld.env.libc_path = cols[2]
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def build_symbol_sets(bld, tgt_list):
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'''build the public_symbols and undefined_symbols attributes for each target'''
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if bld.env.public_symbols:
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objlist = [] # list of object file
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objmap = {} # map from object filename to target (subsystem) name
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t.public_symbols = set()
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t.undefined_symbols = set()
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t.used_symbols = set()
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for tsk in getattr(t, 'compiled_tasks', []):
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for output in tsk.outputs:
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objpath = output.abspath(bld.env)
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objlist.append(objpath)
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symbols = symbols_extract(objlist)
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t.public_symbols = t.public_symbols.union(symbols[obj]["PUBLIC"])
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t.undefined_symbols = t.undefined_symbols.union(symbols[obj]["UNDEFINED"])
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t.used_symbols = t.used_symbols.union(symbols[obj]["UNDEFINED"])
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t.undefined_symbols = t.undefined_symbols.difference(t.public_symbols)
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# and the reverse map of public symbols to subsystem name
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bld.env.symbol_map = {}
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for s in t.public_symbols:
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if not s in bld.env.symbol_map:
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bld.env.symbol_map[s] = []
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bld.env.symbol_map[s].append(real_name(t.sname))
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targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
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bld.env.public_symbols = {}
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name = real_name(t.sname)
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if name in bld.env.public_symbols:
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bld.env.public_symbols[name] = bld.env.public_symbols[name].union(t.public_symbols)
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bld.env.public_symbols[name] = t.public_symbols
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if t.samba_type == 'LIBRARY':
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for dep in t.add_objects:
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t2 = bld.name_to_obj(dep, bld.env)
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bld.ASSERT(t2 is not None, "Library '%s' has unknown dependency '%s'" % (name, dep))
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bld.env.public_symbols[name] = bld.env.public_symbols[name].union(t2.public_symbols)
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bld.env.used_symbols = {}
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name = real_name(t.sname)
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if name in bld.env.used_symbols:
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bld.env.used_symbols[name] = bld.env.used_symbols[name].union(t.used_symbols)
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bld.env.used_symbols[name] = t.used_symbols
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if t.samba_type == 'LIBRARY':
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for dep in t.add_objects:
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t2 = bld.name_to_obj(dep, bld.env)
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bld.ASSERT(t2 is not None, "Library '%s' has unknown dependency '%s'" % (name, dep))
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bld.env.used_symbols[name] = bld.env.used_symbols[name].union(t2.used_symbols)
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def build_syslib_sets(bld, tgt_list):
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'''build the public_symbols for all syslibs'''
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if bld.env.syslib_symbols:
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# work out what syslibs we depend on, and what targets those are used in
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if getattr(t, 'uselib', []) and t.samba_type in [ 'LIBRARY', 'BINARY', 'PYTHON' ]:
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if lib in ['PYEMBED', 'PYEXT']:
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if not lib in syslibs:
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syslibs[lib].append(t)
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# work out the paths to each syslib
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path = find_syslib_path(bld, lib, syslibs[lib])
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Logs.warn("Unable to find syslib path for %s" % lib)
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syslib_paths.append(path)
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objmap[path] = lib.lower()
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syslib_paths.append(bld.env.libc_path)
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objmap[bld.env.libc_path] = 'c'
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symbols = symbols_extract(syslib_paths, dynamic=True)
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# keep a map of syslib names to public symbols
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bld.env.syslib_symbols = {}
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bld.env.syslib_symbols[lib] = symbols[lib]["PUBLIC"]
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# add to the map of symbols to dependencies
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for sym in symbols[lib]["PUBLIC"]:
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if not sym in bld.env.symbol_map:
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bld.env.symbol_map[sym] = []
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bld.env.symbol_map[sym].append(objmap[lib])
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# keep the libc symbols as well, as these are useful for some of the
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bld.env.libc_symbols = symbols[bld.env.libc_path]["PUBLIC"]
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# add to the combined map of dependency name to public_symbols
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for lib in bld.env.syslib_symbols:
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bld.env.public_symbols[objmap[lib]] = bld.env.syslib_symbols[lib]
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def build_autodeps(bld, t):
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'''build the set of dependencies for a target'''
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name = real_name(t.sname)
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targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
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for sym in t.undefined_symbols:
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if sym in t.public_symbols:
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if sym in bld.env.symbol_map:
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depname = bld.env.symbol_map[sym]
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if depname == [ name ]:
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# self dependencies aren't interesting
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if t.in_library == depname:
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# no need to depend on the library we are part of
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if depname[0] in ['c', 'python']:
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# these don't go into autodeps
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if targets[depname[0]] in [ 'SYSLIB' ]:
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t2 = bld.name_to_obj(depname[0], bld.env)
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if len(t2.in_library) != 1:
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if t2.in_library == t.in_library:
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# if we're part of the same library, we don't need to autodep
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deps.add(t2.in_library[0])
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def build_library_names(bld, tgt_list):
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'''add a in_library attribute to all targets that are part of a library'''
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if bld.env.done_build_library_names:
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if t.samba_type in [ 'LIBRARY' ]:
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for obj in t.samba_deps_extended:
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t2 = bld.name_to_obj(obj, bld.env)
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if t2 and t2.samba_type in [ 'SUBSYSTEM', 'ASN1' ]:
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if not t.sname in t2.in_library:
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t2.in_library.append(t.sname)
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bld.env.done_build_library_names = True
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def check_library_deps(bld, t):
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'''check that all the autodeps that have mutual dependency of this
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target are in the same library as the target'''
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name = real_name(t.sname)
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if len(t.in_library) > 1:
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Logs.warn("WARNING: Target '%s' in multiple libraries: %s" % (t.sname, t.in_library))
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for dep in t.autodeps:
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t2 = bld.name_to_obj(dep, bld.env)
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for dep2 in t2.autodeps:
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if dep2 == name and t.in_library != t2.in_library:
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Logs.warn("WARNING: mutual dependency %s <=> %s" % (name, real_name(t2.sname)))
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Logs.warn("Libraries should match. %s != %s" % (t.in_library, t2.in_library))
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# raise Utils.WafError("illegal mutual dependency")
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def check_syslib_collisions(bld, tgt_list):
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'''check if a target has any symbol collisions with a syslib
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We do not want any code in Samba to use a symbol name from a
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system library. The chance of that causing problems is just too
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high. Note that libreplace uses a rep_XX approach of renaming
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for lib in bld.env.syslib_symbols:
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common = t.public_symbols.intersection(bld.env.syslib_symbols[lib])
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Logs.error("ERROR: Target '%s' has symbols '%s' which is also in syslib '%s'" % (t.sname, common, lib))
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raise Utils.WafError("symbols in common with system libraries")
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def check_dependencies(bld, t):
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'''check for depenencies that should be changed'''
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if bld.name_to_obj(t.sname + ".objlist", bld.env):
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targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
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remaining = t.undefined_symbols.copy()
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remaining = remaining.difference(t.public_symbols)
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sname = real_name(t.sname)
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deps = set(t.samba_deps)
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for d in t.samba_deps:
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if targets[d] in [ 'EMPTY', 'DISABLED', 'SYSLIB' ]:
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bld.ASSERT(d in bld.env.public_symbols, "Failed to find symbol list for dependency '%s'" % d)
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diff = remaining.intersection(bld.env.public_symbols[d])
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if not diff and targets[sname] != 'LIBRARY':
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Logs.info("Target '%s' has no dependency on %s" % (sname, d))
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remaining = remaining.difference(diff)
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t.unsatisfied_symbols = set()
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for sym in remaining:
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if sym in bld.env.symbol_map:
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dep = bld.env.symbol_map[sym]
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if not dep[0] in needed:
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needed[dep[0]] = set()
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needed[dep[0]].add(sym)
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t.unsatisfied_symbols.add(sym)
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Logs.info("Target '%s' should add dep '%s' for symbols %s" % (sname, dep, " ".join(needed[dep])))
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def check_syslib_dependencies(bld, t):
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'''check for syslib depenencies'''
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if bld.name_to_obj(t.sname + ".objlist", bld.env):
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sname = real_name(t.sname)
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features = TO_LIST(t.features)
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if 'pyembed' in features or 'pyext' in features:
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t.unsatisfied_symbols = t.unsatisfied_symbols.difference(bld.env.public_symbols['python'])
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for sym in t.unsatisfied_symbols:
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if sym in bld.env.symbol_map:
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dep = bld.env.symbol_map[sym][0]
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if not dep in needed:
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Logs.info("Target '%s' should add syslib dep '%s' for symbols %s" % (sname, dep, " ".join(needed[dep])))
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debug("deps: Target '%s' has unsatisfied symbols: %s" % (sname, " ".join(remaining)))
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def symbols_symbolcheck(task):
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'''check the internal dependency lists'''
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tgt_list = get_tgt_list(bld)
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build_symbol_sets(bld, tgt_list)
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build_library_names(bld, tgt_list)
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if getattr(t, 'source', ''):
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build_autodeps(bld, t)
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check_dependencies(bld, t)
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check_library_deps(bld, t)
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def symbols_syslibcheck(task):
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'''check the syslib dependencies'''
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tgt_list = get_tgt_list(bld)
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build_syslib_sets(bld, tgt_list)
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check_syslib_collisions(bld, tgt_list)
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check_syslib_dependencies(bld, t)
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def symbols_whyneeded(task):
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"""check why 'target' needs to link to 'subsystem'"""
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tgt_list = get_tgt_list(bld)
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why = Options.options.WHYNEEDED.split(":")
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raise Utils.WafError("usage: WHYNEEDED=TARGET:DEPENDENCY")
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build_symbol_sets(bld, tgt_list)
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build_library_names(bld, tgt_list)
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build_syslib_sets(bld, tgt_list)
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Logs.info("Checking why %s needs to link to %s" % (target, subsystem))
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if not target in bld.env.used_symbols:
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Logs.warn("unable to find target '%s' in used_symbols dict" % target)
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if not subsystem in bld.env.public_symbols:
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Logs.warn("unable to find subsystem '%s' in public_symbols dict" % subsystem)
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overlap = bld.env.used_symbols[target].intersection(bld.env.public_symbols[subsystem])
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Logs.info("target '%s' doesn't use any public symbols from '%s'" % (target, subsystem))
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Logs.info("target '%s' uses symbols %s from '%s'" % (target, overlap, subsystem))
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def symbols_dupcheck(task):
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'''check for symbols defined in two different subsystems'''
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tgt_list = get_tgt_list(bld)
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targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
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Logs.info("Checking for duplicate symbols")
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for sym in bld.env.symbol_map:
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subsystems = set(bld.env.symbol_map[sym])
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if len(subsystems) == 1:
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if sym in ['main', '_init', '_fini', 'init_samba_module', 'samba_init_module', 'ldb_init_module' ]:
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# these are expected to be in many subsystems
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# if all of them are in system libraries, we can ignore them. This copes
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# with the duplication between libc, libpthread and libattr
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if s != 'c' and (not s in targets or targets[s] != 'SYSLIB'):
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Logs.info("symbol %s appears in %s" % (sym, subsystems))
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def SYMBOL_CHECK(bld):
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'''check our dependency lists'''
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if Options.options.SYMBOLCHECK:
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bld.SET_BUILD_GROUP('symbolcheck')
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task = bld(rule=symbols_symbolcheck, always=True, name='symbol checking')
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bld.SET_BUILD_GROUP('syslibcheck')
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task = bld(rule=symbols_syslibcheck, always=True, name='syslib checking')
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bld.SET_BUILD_GROUP('syslibcheck')
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task = bld(rule=symbols_dupcheck, always=True, name='symbol duplicate checking')
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if Options.options.WHYNEEDED:
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bld.SET_BUILD_GROUP('syslibcheck')
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task = bld(rule=symbols_whyneeded, always=True, name='check why a dependency is needed')
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Build.BuildContext.SYMBOL_CHECK = SYMBOL_CHECK