Adding upstream version 2.4.0.upstream/2.4.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1314 insertions, 0 deletions

diff --git a/buildtools/wafsamba/samba_deps.py b/buildtools/wafsamba/samba_deps.py
new file mode 100644
index 0000000..66adf40
--- /dev/null
+++ b/buildtools/wafsamba/samba_deps.py
@@ -0,0 +1,1314 @@
+# Samba automatic dependency handling and project rules
+
+import os, sys, re
+
+from waflib import Build, Options, Logs, Utils, Errors, Task
+from waflib.Logs import debug
+from waflib.Configure import conf
+from waflib import ConfigSet
+
+from samba_utils import LOCAL_CACHE, TO_LIST, get_tgt_list, unique_list
+from samba_autoconf import library_flags
+
+@conf
+def ADD_GLOBAL_DEPENDENCY(ctx, dep):
+    '''add a dependency for all binaries and libraries'''
+    if not 'GLOBAL_DEPENDENCIES' in ctx.env:
+        ctx.env.GLOBAL_DEPENDENCIES = []
+    ctx.env.GLOBAL_DEPENDENCIES.append(dep)
+
+
+@conf
+def BREAK_CIRCULAR_LIBRARY_DEPENDENCIES(ctx):
+    '''indicate that circular dependencies between libraries should be broken.'''
+    ctx.env.ALLOW_CIRCULAR_LIB_DEPENDENCIES = True
+
+
+@conf
+def SET_SYSLIB_DEPS(conf, target, deps):
+    '''setup some implied dependencies for a SYSLIB'''
+    cache = LOCAL_CACHE(conf, 'SYSLIB_DEPS')
+    cache[target] = deps
+
+
+def expand_subsystem_deps(bld):
+    '''expand the reverse dependencies resulting from subsystem
+       attributes of modules. This is walking over the complete list
+       of declared subsystems, and expands the samba_deps_extended list for any
+       module<->subsystem dependencies'''
+
+    subsystem_list = LOCAL_CACHE(bld, 'INIT_FUNCTIONS')
+    targets    = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    for subsystem_name in subsystem_list:
+        bld.ASSERT(subsystem_name in targets, "Subsystem target %s not declared" % subsystem_name)
+        type = targets[subsystem_name]
+        if type == 'DISABLED' or type == 'EMPTY':
+            continue
+
+        # for example,
+        #    subsystem_name = dcerpc_server (a subsystem)
+        #    subsystem      = dcerpc_server (a subsystem object)
+        #    module_name    = rpc_epmapper (a module within the dcerpc_server subsystem)
+        #    module         = rpc_epmapper (a module object within the dcerpc_server subsystem)
+
+        subsystem = bld.get_tgen_by_name(subsystem_name)
+        bld.ASSERT(subsystem is not None, "Unable to find subsystem %s" % subsystem_name)
+        for d in subsystem_list[subsystem_name]:
+            module_name = d['TARGET']
+            module_type = targets[module_name]
+            if module_type in ['DISABLED', 'EMPTY']:
+                continue
+            bld.ASSERT(subsystem is not None,
+                       "Subsystem target %s for %s (%s) not found" % (subsystem_name, module_name, module_type))
+            if module_type in ['SUBSYSTEM']:
+                # if a module is a plain object type (not a library) then the
+                # subsystem it is part of needs to have it as a dependency, so targets
+                # that depend on this subsystem get the modules of that subsystem
+                subsystem.samba_deps_extended.append(module_name)
+        subsystem.samba_deps_extended = unique_list(subsystem.samba_deps_extended)
+
+
+
+def build_dependencies(self):
+    '''This builds the dependency list for a target. It runs after all the targets are declared
+
+    The reason this is not just done in the SAMBA_*() rules is that we have no way of knowing
+    the full dependency list for a target until we have all of the targets declared.
+    '''
+
+    if self.samba_type in ['LIBRARY', 'PLUGIN', 'BINARY', 'PYTHON']:
+        self.uselib        = list(self.final_syslibs)
+        self.uselib_local  = list(self.final_libs)
+        self.add_objects   = list(self.final_objects)
+
+        # extra link flags from pkg_config
+        libs = self.final_syslibs.copy()
+
+        (cflags, ldflags, cpppath) = library_flags(self, list(libs))
+        new_ldflags        = getattr(self, 'samba_ldflags', [])[:]
+        new_ldflags.extend(ldflags)
+        self.ldflags       = new_ldflags
+
+        if getattr(self, 'allow_undefined_symbols', False) and self.env.undefined_ldflags:
+            for f in self.env.undefined_ldflags:
+                self.ldflags.remove(f)
+
+        if getattr(self, 'allow_undefined_symbols', False) and self.env.undefined_ignore_ldflags:
+            for f in self.env.undefined_ignore_ldflags:
+                self.ldflags.append(f)
+
+        debug('deps: computed dependencies for target %s: uselib=%s uselib_local=%s add_objects=%s',
+              self.sname, self.uselib, self.uselib_local, self.add_objects)
+
+    if self.samba_type in ['SUBSYSTEM', 'BUILTIN']:
+        # this is needed for the cflags of libs that come from pkg_config
+        self.uselib = list(self.final_syslibs)
+        self.uselib.extend(list(self.direct_syslibs))
+        for lib in self.final_libs:
+            t = self.bld.get_tgen_by_name(lib)
+            self.uselib.extend(list(t.final_syslibs))
+        self.uselib = unique_list(self.uselib)
+
+    if getattr(self, 'uselib', None):
+        up_list = []
+        for l in self.uselib:
+           up_list.append(l.upper())
+        self.uselib = up_list
+
+
+def build_includes(self):
+    '''This builds the right set of includes for a target.
+
+    One tricky part of this is that the includes= attribute for a
+    target needs to use paths which are relative to that targets
+    declaration directory (which we can get at via t.path).
+
+    The way this works is the includes list gets added as
+    samba_includes in the main build task declaration. Then this
+    function runs after all of the tasks are declared, and it
+    processes the samba_includes attribute to produce a includes=
+    attribute
+    '''
+
+    if getattr(self, 'samba_includes', None) is None:
+        return
+
+    bld = self.bld
+
+    inc_deps = includes_objects(bld, self, set(), {})
+
+    includes = []
+
+    # maybe add local includes
+    if getattr(self, 'local_include', True) and getattr(self, 'local_include_first', True):
+        includes.append('.')
+
+    includes.extend(self.samba_includes_extended)
+
+    if 'EXTRA_INCLUDES' in bld.env and getattr(self, 'global_include', True):
+        includes.extend(bld.env['EXTRA_INCLUDES'])
+
+    includes.append('#')
+
+    inc_set = set()
+    inc_abs = []
+
+    for d in inc_deps:
+        t = bld.get_tgen_by_name(d)
+        bld.ASSERT(t is not None, "Unable to find dependency %s for %s" % (d, self.sname))
+        inclist = getattr(t, 'samba_includes_extended', [])[:]
+        if getattr(t, 'local_include', True):
+            inclist.append('.')
+        if inclist == []:
+            continue
+        tpath = t.samba_abspath
+        for inc in inclist:
+            npath = tpath + '/' + inc
+            if not npath in inc_set:
+                inc_abs.append(npath)
+                inc_set.add(npath)
+
+    mypath = self.path.abspath(bld.env)
+    for inc in inc_abs:
+        relpath = os.path.relpath(inc, mypath)
+        includes.append(relpath)
+
+    if getattr(self, 'local_include', True) and not getattr(self, 'local_include_first', True):
+        includes.append('.')
+
+    # now transform the includes list to be relative to the top directory
+    # which is represented by '#' in waf. This allows waf to cache the
+    # includes lists more efficiently
+    includes_top = []
+    for i in includes:
+        if i[0] == '#':
+            # some are already top based
+            includes_top.append(i)
+            continue
+        absinc = os.path.join(self.path.abspath(), i)
+        relinc = os.path.relpath(absinc, self.bld.srcnode.abspath())
+        includes_top.append('#' + relinc)
+
+    self.includes = unique_list(includes_top)
+    debug('deps: includes for target %s: includes=%s',
+          self.sname, self.includes)
+
+
+def add_init_functions(self):
+    '''This builds the right set of init functions'''
+
+    bld = self.bld
+
+    subsystems = LOCAL_CACHE(bld, 'INIT_FUNCTIONS')
+
+    # cope with the separated object lists from BINARY and LIBRARY targets
+    sname = self.sname
+    if sname.endswith('.objlist'):
+        sname = sname[0:-8]
+
+    modules = []
+    if sname in subsystems:
+        modules.append(sname)
+
+    m = getattr(self, 'samba_modules', None)
+    if m is not None:
+        modules.extend(TO_LIST(m))
+
+    m = getattr(self, 'samba_subsystem', None)
+    if m is not None:
+        modules.append(m)
+
+    if 'pyembed' in self.features:
+        return
+
+    sentinel = getattr(self, 'init_function_sentinel', 'NULL')
+
+    targets    = LOCAL_CACHE(bld, 'TARGET_TYPE')
+    cflags = getattr(self, 'samba_cflags', [])[:]
+
+    if modules == []:
+        sname = sname.replace('-','_')
+        sname = sname.replace('.','_')
+        sname = sname.replace('/','_')
+        cflags.append('-DSTATIC_%s_MODULES=%s' % (sname, sentinel))
+        if sentinel == 'NULL':
+            proto = "extern void __%s_dummy_module_proto(void)" % (sname)
+            cflags.append('-DSTATIC_%s_MODULES_PROTO=%s' % (sname, proto))
+        self.cflags = cflags
+        return
+
+    for m in modules:
+        bld.ASSERT(m in subsystems,
+                   "No init_function defined for module '%s' in target '%s'" % (m, self.sname))
+        init_fn_list = []
+        for d in subsystems[m]:
+            if targets[d['TARGET']] != 'DISABLED':
+                init_fn_list.append(d['INIT_FUNCTION'])
+        if init_fn_list == []:
+            cflags.append('-DSTATIC_%s_MODULES=%s' % (m, sentinel))
+            if sentinel == 'NULL':
+                proto = "extern void __%s_dummy_module_proto(void)" % (m)
+                cflags.append('-DSTATIC_%s_MODULES_PROTO=%s' % (m, proto))
+        else:
+            cflags.append('-DSTATIC_%s_MODULES=%s' % (m, ','.join(init_fn_list) + ',' + sentinel))
+            proto = "".join('_MODULE_PROTO(%s)' % f for f in init_fn_list) +\
+                    "extern void __%s_dummy_module_proto(void)" % (m)
+            cflags.append('-DSTATIC_%s_MODULES_PROTO=%s' % (m, proto))
+    self.cflags = cflags
+
+
+def check_duplicate_sources(bld, tgt_list):
+    '''see if we are compiling the same source file more than once'''
+
+    debug('deps: checking for duplicate sources')
+    targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    for t in tgt_list:
+        source_list = TO_LIST(getattr(t, 'source', ''))
+        tpath = os.path.normpath(os.path.relpath(t.path.abspath(bld.env), t.env.BUILD_DIRECTORY + '/default'))
+        obj_sources = set()
+        for s in source_list:
+            if not isinstance(s, str):
+                print('strange path in check_duplicate_sources %r' % s)
+                s = s.abspath()
+            p = os.path.normpath(os.path.join(tpath, s))
+            if p in obj_sources:
+                Logs.error("ERROR: source %s appears twice in target '%s'" % (p, t.sname))
+                sys.exit(1)
+            obj_sources.add(p)
+        t.samba_source_set = obj_sources
+
+    subsystems = {}
+
+    # build a list of targets that each source file is part of
+    for t in tgt_list:
+        if not targets[t.sname] in [ 'LIBRARY', 'PLUGIN', 'BINARY', 'PYTHON' ]:
+            continue
+        for obj in t.add_objects:
+            t2 = t.bld.get_tgen_by_name(obj)
+            source_set = getattr(t2, 'samba_source_set', set())
+            for s in source_set:
+                if not s in subsystems:
+                    subsystems[s] = {}
+                if not t.sname in subsystems[s]:
+                    subsystems[s][t.sname] = []
+                subsystems[s][t.sname].append(t2.sname)
+
+    for s in subsystems:
+        if len(subsystems[s]) > 1 and Options.options.SHOW_DUPLICATES:
+            Logs.warn("WARNING: source %s is in more than one target: %s" % (s, subsystems[s].keys()))
+        for tname in subsystems[s]:
+            if len(subsystems[s][tname]) > 1:
+                raise Errors.WafError("ERROR: source %s is in more than one subsystem of target '%s': %s" % (s, tname, subsystems[s][tname]))
+
+    return True
+
+def check_group_ordering(bld, tgt_list):
+    '''see if we have any dependencies that violate the group ordering
+
+    It is an error for a target to depend on a target from a later
+    build group
+    '''
+
+    def group_name(g):
+        tm = bld.task_manager
+        return [x for x in tm.groups_names if id(tm.groups_names[x]) == id(g)][0]
+
+    for g in bld.task_manager.groups:
+        gname = group_name(g)
+        for t in g.tasks_gen:
+            t.samba_group = gname
+
+    grp_map = {}
+    idx = 0
+    for g in bld.task_manager.groups:
+        name = group_name(g)
+        grp_map[name] = idx
+        idx += 1
+
+    targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    ret = True
+    for t in tgt_list:
+        tdeps = getattr(t, 'add_objects', []) + getattr(t, 'uselib_local', [])
+        for d in tdeps:
+            t2 = bld.get_tgen_by_name(d)
+            if t2 is None:
+                continue
+            map1 = grp_map[t.samba_group]
+            map2 = grp_map[t2.samba_group]
+
+            if map2 > map1:
+                Logs.error("Target %r in build group %r depends on target %r from later build group %r" % (
+                           t.sname, t.samba_group, t2.sname, t2.samba_group))
+                ret = False
+
+    return ret
+Build.BuildContext.check_group_ordering = check_group_ordering
+
+def show_final_deps(bld, tgt_list):
+    '''show the final dependencies for all targets'''
+
+    targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    for t in tgt_list:
+        if not targets[t.sname] in ['LIBRARY', 'PLUGIN', 'BINARY', 'PYTHON', 'SUBSYSTEM', 'BUILTIN']:
+            continue
+        debug('deps: final dependencies for target %s: uselib=%s uselib_local=%s add_objects=%s',
+              t.sname, t.uselib, getattr(t, 'uselib_local', []), getattr(t, 'add_objects', []))
+
+
+def add_samba_attributes(bld, tgt_list):
+    '''ensure a target has a the required samba attributes'''
+
+    targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    for t in tgt_list:
+        if t.name != '':
+            t.sname = t.name
+        else:
+            t.sname = t.target
+        t.samba_type = targets[t.sname]
+        t.samba_abspath = t.path.abspath(bld.env)
+        t.samba_deps_extended = t.samba_deps[:]
+        t.samba_includes_extended = TO_LIST(t.samba_includes)[:]
+        t.cflags = getattr(t, 'samba_cflags', '')
+
+def replace_builtin_subsystem_deps(bld, tgt_list):
+    '''replace dependencies based on builtin subsystems/libraries
+
+    '''
+
+    targets  = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    # If either the target or the dependency require builtin linking
+    # we should replace the dependency
+    for t in tgt_list:
+        t_require_builtin_deps = getattr(t, 'samba_require_builtin_deps', False)
+        if t_require_builtin_deps:
+            debug("deps: target %s: requires builtin dependencies..." % (t.sname))
+        else:
+            debug("deps: target %s: does not require builtin dependencies..." % (t.sname))
+
+        replacing = {}
+
+        for dep in t.samba_deps_extended:
+            bld.ASSERT(dep in targets, "target %s: dependency target %s not declared" % (t.sname, dep))
+            dtype = targets[dep]
+            bld.ASSERT(dtype != 'BUILTIN', "target %s: dependency target %s is BUILTIN" % (t.sname, dep))
+            bld.ASSERT(dtype != 'PLUGIN', "target %s: dependency target %s is PLUGIN" % (t.sname, dep))
+            if dtype not in ['SUBSYSTEM', 'LIBRARY']:
+                debug("deps: target %s: keep %s dependency %s" % (t.sname, dtype, dep))
+                continue
+            dt = bld.get_tgen_by_name(dep)
+            bld.ASSERT(dt is not None, "target %s: dependency target %s not found by name" % (t.sname, dep))
+            dt_require_builtin_deps = getattr(dt, 'samba_require_builtin_deps', False)
+            if not dt_require_builtin_deps and not t_require_builtin_deps:
+                # both target and dependency don't require builtin linking
+                continue
+            sdt = getattr(dt, 'samba_builtin_subsystem', None)
+            if not t_require_builtin_deps:
+                if sdt is None:
+                    debug("deps: target %s: dependency %s requires builtin deps only" % (t.sname, dep))
+                    continue
+                debug("deps: target %s: dependency %s requires builtin linking" % (t.sname, dep))
+            bld.ASSERT(sdt is not None, "target %s: dependency target %s is missing samba_builtin_subsystem" % (t.sname, dep))
+            sdep = sdt.sname
+            bld.ASSERT(sdep in targets, "target %s: builtin dependency target %s (from %s) not declared" % (t.sname, sdep, dep))
+            sdt = targets[sdep]
+            bld.ASSERT(sdt == 'BUILTIN', "target %s: builtin dependency target %s (from %s) is not BUILTIN" % (t.sname, sdep, dep))
+            replacing[dep] = sdep
+
+        for i in range(len(t.samba_deps_extended)):
+            dep = t.samba_deps_extended[i]
+            if dep in replacing:
+                sdep = replacing[dep]
+                debug("deps: target %s: replacing dependency %s with builtin subsystem %s" % (t.sname, dep, sdep))
+                t.samba_deps_extended[i] = sdep
+
+def replace_grouping_libraries(bld, tgt_list):
+    '''replace dependencies based on grouping libraries
+
+    If a library is marked as a grouping library, then any target that
+    depends on a subsystem that is part of that grouping library gets
+    that dependency replaced with a dependency on the grouping library
+    '''
+
+    targets  = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    grouping = {}
+
+    # find our list of grouping libraries, mapped from the subsystems they depend on
+    for t in tgt_list:
+        if not getattr(t, 'grouping_library', False):
+            continue
+        for dep in t.samba_deps_extended:
+            bld.ASSERT(dep in targets, "grouping library target %s not declared in %s" % (dep, t.sname))
+            if targets[dep] == 'SUBSYSTEM':
+                grouping[dep] = t.sname
+
+    # now replace any dependencies on elements of grouping libraries
+    for t in tgt_list:
+        for i in range(len(t.samba_deps_extended)):
+            dep = t.samba_deps_extended[i]
+            if dep in grouping:
+                if t.sname != grouping[dep]:
+                    debug("deps: target %s: replacing dependency %s with grouping library %s" % (t.sname, dep, grouping[dep]))
+                    t.samba_deps_extended[i] = grouping[dep]
+
+
+
+def build_direct_deps(bld, tgt_list):
+    '''build the direct_objects and direct_libs sets for each target'''
+
+    targets  = LOCAL_CACHE(bld, 'TARGET_TYPE')
+    syslib_deps  = LOCAL_CACHE(bld, 'SYSLIB_DEPS')
+
+    global_deps = bld.env.GLOBAL_DEPENDENCIES
+    global_deps_exclude = set()
+    for dep in global_deps:
+        t = bld.get_tgen_by_name(dep)
+        for d in t.samba_deps:
+            # prevent loops from the global dependencies list
+            global_deps_exclude.add(d)
+            global_deps_exclude.add(d + '.objlist')
+
+    for t in tgt_list:
+        t.direct_objects = set()
+        t.direct_libs = set()
+        t.direct_syslibs = set()
+        deps = t.samba_deps_extended[:]
+        if getattr(t, 'samba_use_global_deps', False) and not t.sname in global_deps_exclude:
+            deps.extend(global_deps)
+        for d in deps:
+            if d == t.sname: continue
+            if not d in targets:
+                Logs.error("Unknown dependency '%s' in '%s'" % (d, t.sname))
+                sys.exit(1)
+            if targets[d] in [ 'EMPTY', 'DISABLED' ]:
+                continue
+            if targets[d] == 'PYTHON' and targets[t.sname] != 'PYTHON' and t.sname.find('.objlist') == -1:
+                # this check should be more restrictive, but for now we have pidl-generated python
+                # code that directly depends on other python modules
+                Logs.error('ERROR: Target %s has dependency on python module %s' % (t.sname, d))
+                sys.exit(1)
+            if targets[d] == 'SYSLIB':
+                t.direct_syslibs.add(d)
+                if d in syslib_deps:
+                    for implied in TO_LIST(syslib_deps[d]):
+                        if targets[implied] == 'SUBSYSTEM':
+                            it = bld.get_tgen_by_name(implied)
+                            sit = getattr(it, 'samba_builtin_subsystem', None)
+                            if sit:
+                                implied = sit.sname
+                        if targets[implied] == 'BUILTIN':
+                            t.direct_objects.add(implied)
+                        elif targets[implied] == 'SYSLIB':
+                            t.direct_syslibs.add(implied)
+                        elif targets[implied] in ['LIBRARY', 'MODULE']:
+                            t.direct_libs.add(implied)
+                        else:
+                            Logs.error('Implied dependency %s in %s is of type %s' % (
+                                implied, t.sname, targets[implied]))
+                            sys.exit(1)
+                continue
+            t2 = bld.get_tgen_by_name(d)
+            if t2 is None:
+                Logs.error("no task %s of type %s in %s" % (d, targets[d], t.sname))
+                sys.exit(1)
+            if t2.samba_type in [ 'LIBRARY', 'MODULE' ]:
+                t.direct_libs.add(d)
+            elif t2.samba_type in [ 'SUBSYSTEM', 'BUILTIN', 'ASN1', 'PYTHON' ]:
+                t.direct_objects.add(d)
+            elif t2.samba_type in [ 'PLUGIN' ]:
+                Logs.error('Implicit dependency %s in %s is of type %s' % (
+                           d, t.sname, t2.samba_type))
+                sys.exit(1)
+
+    debug('deps: built direct dependencies')
+
+
+def dependency_loop(loops, t, target):
+    '''add a dependency loop to the loops dictionary'''
+    if t.sname == target:
+        return
+    if not target in loops:
+        loops[target] = set()
+    if not t.sname in loops[target]:
+        loops[target].add(t.sname)
+
+
+def indirect_libs(bld, t, chain, loops):
+    '''recursively calculate the indirect library dependencies for a target
+
+    An indirect library is a library that results from a dependency on
+    a subsystem
+    '''
+
+    ret = getattr(t, 'indirect_libs', None)
+    if ret is not None:
+        return ret
+
+    ret = set()
+    for obj in t.direct_objects:
+        if obj in chain:
+            dependency_loop(loops, t, obj)
+            continue
+        chain.add(obj)
+        t2 = bld.get_tgen_by_name(obj)
+        r2 = indirect_libs(bld, t2, chain, loops)
+        chain.remove(obj)
+        ret = ret.union(t2.direct_libs)
+        ret = ret.union(r2)
+
+    for obj in indirect_objects(bld, t, set(), loops):
+        if obj in chain:
+            dependency_loop(loops, t, obj)
+            continue
+        chain.add(obj)
+        t2 = bld.get_tgen_by_name(obj)
+        r2 = indirect_libs(bld, t2, chain, loops)
+        chain.remove(obj)
+        ret = ret.union(t2.direct_libs)
+        ret = ret.union(r2)
+
+    t.indirect_libs = ret
+
+    return ret
+
+
+def indirect_objects(bld, t, chain, loops):
+    '''recursively calculate the indirect object dependencies for a target
+
+    indirect objects are the set of objects from expanding the
+    subsystem dependencies
+    '''
+
+    ret = getattr(t, 'indirect_objects', None)
+    if ret is not None: return ret
+
+    ret = set()
+    for lib in t.direct_objects:
+        if lib in chain:
+            dependency_loop(loops, t, lib)
+            continue
+        chain.add(lib)
+        t2 = bld.get_tgen_by_name(lib)
+        r2 = indirect_objects(bld, t2, chain, loops)
+        chain.remove(lib)
+        ret = ret.union(t2.direct_objects)
+        ret = ret.union(r2)
+
+    t.indirect_objects = ret
+    return ret
+
+
+def extended_objects(bld, t, chain):
+    '''recursively calculate the extended object dependencies for a target
+
+    extended objects are the union of:
+       - direct objects
+       - indirect objects
+       - direct and indirect objects of all direct and indirect libraries
+    '''
+
+    ret = getattr(t, 'extended_objects', None)
+    if ret is not None: return ret
+
+    ret = set()
+    ret = ret.union(t.final_objects)
+
+    for lib in t.final_libs:
+        if lib in chain:
+            continue
+        t2 = bld.get_tgen_by_name(lib)
+        chain.add(lib)
+        r2 = extended_objects(bld, t2, chain)
+        chain.remove(lib)
+        ret = ret.union(t2.final_objects)
+        ret = ret.union(r2)
+
+    t.extended_objects = ret
+    return ret
+
+
+def includes_objects(bld, t, chain, inc_loops):
+    '''recursively calculate the includes object dependencies for a target
+
+    includes dependencies come from either library or object dependencies
+    '''
+    ret = getattr(t, 'includes_objects', None)
+    if ret is not None:
+        return ret
+
+    ret = t.direct_objects.copy()
+    ret = ret.union(t.direct_libs)
+
+    for obj in t.direct_objects:
+        if obj in chain:
+            dependency_loop(inc_loops, t, obj)
+            continue
+        chain.add(obj)
+        t2 = bld.get_tgen_by_name(obj)
+        r2 = includes_objects(bld, t2, chain, inc_loops)
+        chain.remove(obj)
+        ret = ret.union(t2.direct_objects)
+        ret = ret.union(r2)
+
+    for lib in t.direct_libs:
+        if lib in chain:
+            dependency_loop(inc_loops, t, lib)
+            continue
+        chain.add(lib)
+        t2 = bld.get_tgen_by_name(lib)
+        if t2 is None:
+            targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+            Logs.error('Target %s of type %s not found in direct_libs for %s' % (
+                lib, targets[lib], t.sname))
+            sys.exit(1)
+        r2 = includes_objects(bld, t2, chain, inc_loops)
+        chain.remove(lib)
+        ret = ret.union(t2.direct_objects)
+        ret = ret.union(r2)
+
+    t.includes_objects = ret
+    return ret
+
+
+def break_dependency_loops(bld, tgt_list):
+    '''find and break dependency loops'''
+    loops = {}
+    inc_loops = {}
+
+    # build up the list of loops
+    for t in tgt_list:
+        indirect_objects(bld, t, set(), loops)
+        indirect_libs(bld, t, set(), loops)
+        includes_objects(bld, t, set(), inc_loops)
+
+    # break the loops
+    for t in tgt_list:
+        if t.sname in loops:
+            for attr in ['direct_objects', 'indirect_objects', 'direct_libs', 'indirect_libs']:
+                objs = getattr(t, attr, set())
+                setattr(t, attr, objs.difference(loops[t.sname]))
+
+    for loop in loops:
+        debug('deps: Found dependency loops for target %s : %s', loop, loops[loop])
+
+    for loop in inc_loops:
+        debug('deps: Found include loops for target %s : %s', loop, inc_loops[loop])
+
+    # expand the loops mapping by one level
+    for loop in loops.copy():
+        for tgt in loops[loop]:
+            if tgt in loops:
+                loops[loop] = loops[loop].union(loops[tgt])
+
+    for loop in inc_loops.copy():
+        for tgt in inc_loops[loop]:
+            if tgt in inc_loops:
+                inc_loops[loop] = inc_loops[loop].union(inc_loops[tgt])
+
+
+    # expand indirect subsystem and library loops
+    for loop in loops.copy():
+        t = bld.get_tgen_by_name(loop)
+        if t.samba_type in ['SUBSYSTEM', 'BUILTIN']:
+            loops[loop] = loops[loop].union(t.indirect_objects)
+            loops[loop] = loops[loop].union(t.direct_objects)
+        if t.samba_type in ['LIBRARY', 'PLUGIN', 'PYTHON']:
+            loops[loop] = loops[loop].union(t.indirect_libs)
+            loops[loop] = loops[loop].union(t.direct_libs)
+        if loop in loops[loop]:
+            loops[loop].remove(loop)
+
+    # expand indirect includes loops
+    for loop in inc_loops.copy():
+        t = bld.get_tgen_by_name(loop)
+        inc_loops[loop] = inc_loops[loop].union(t.includes_objects)
+        if loop in inc_loops[loop]:
+            inc_loops[loop].remove(loop)
+
+    # add in the replacement dependencies
+    for t in tgt_list:
+        for loop in loops:
+            for attr in ['indirect_objects', 'indirect_libs']:
+                objs = getattr(t, attr, set())
+                if loop in objs:
+                    diff = loops[loop].difference(objs)
+                    if t.sname in diff:
+                        diff.remove(t.sname)
+                    if diff:
+                        debug('deps: Expanded target %s of type %s from loop %s by %s', t.sname, t.samba_type, loop, diff)
+                        objs = objs.union(diff)
+                setattr(t, attr, objs)
+
+        for loop in inc_loops:
+            objs = getattr(t, 'includes_objects', set())
+            if loop in objs:
+                diff = inc_loops[loop].difference(objs)
+                if t.sname in diff:
+                    diff.remove(t.sname)
+                if diff:
+                    debug('deps: Expanded target %s includes of type %s from loop %s by %s', t.sname, t.samba_type, loop, diff)
+                    objs = objs.union(diff)
+            setattr(t, 'includes_objects', objs)
+
+
+def reduce_objects(bld, tgt_list):
+    '''reduce objects by looking for indirect object dependencies'''
+    targets  = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    rely_on = {}
+
+    for t in tgt_list:
+        t.extended_objects = None
+
+    changed = False
+
+    for type in ['BINARY', 'PYTHON', 'LIBRARY', 'PLUGIN']:
+        for t in tgt_list:
+            if t.samba_type != type: continue
+            # if we will indirectly link to a target then we don't need it
+            new = t.final_objects.copy()
+            for l in t.final_libs:
+                t2 = bld.get_tgen_by_name(l)
+                t2_obj = extended_objects(bld, t2, set())
+                dup = new.intersection(t2_obj)
+                if t.sname in rely_on:
+                    dup = dup.difference(rely_on[t.sname])
+                if dup:
+                    # Do not remove duplicates of BUILTINS
+                    for d in iter(dup.copy()):
+                        dtype = targets[d]
+                        if dtype == 'BUILTIN':
+                            debug('deps: BUILTIN SKIP: removing dups from %s of type %s: %s also in %s %s',
+                                  t.sname, t.samba_type, d, t2.samba_type, l)
+                            dup.remove(d)
+                    if len(dup) == 0:
+                        continue
+
+                    debug('deps: removing dups from %s of type %s: %s also in %s %s',
+                          t.sname, t.samba_type, dup, t2.samba_type, l)
+                    new = new.difference(dup)
+                    changed = True
+                    if not l in rely_on:
+                        rely_on[l] = set()
+                    rely_on[l] = rely_on[l].union(dup)
+            for n in iter(new.copy()):
+                # if we got the builtin version as well
+                # as the native one, we keep using the
+                # builtin one and remove the rest.
+                # Otherwise our check_duplicate_sources()
+                # checks would trigger!
+                if n.endswith('.builtin.objlist'):
+                    unused = n.replace('.builtin.objlist', '.objlist')
+                    if unused in new:
+                        new.remove(unused)
+                    unused = n.replace('.builtin.objlist', '')
+                    if unused in new:
+                        new.remove(unused)
+            t.final_objects = new
+
+    if not changed:
+        return False
+
+    # add back in any objects that were relied upon by the reduction rules
+    for r in rely_on:
+        t = bld.get_tgen_by_name(r)
+        t.final_objects = t.final_objects.union(rely_on[r])
+
+    return True
+
+
+def show_library_loop(bld, lib1, lib2, path, seen):
+    '''show the detailed path of a library loop between lib1 and lib2'''
+
+    t = bld.get_tgen_by_name(lib1)
+    if not lib2 in getattr(t, 'final_libs', set()):
+        return
+
+    for d in t.samba_deps_extended:
+        if d in seen:
+            continue
+        seen.add(d)
+        path2 = path + '=>' + d
+        if d == lib2:
+            Logs.warn('library loop path: ' + path2)
+            return
+        show_library_loop(bld, d, lib2, path2, seen)
+        seen.remove(d)
+
+
+def calculate_final_deps(bld, tgt_list, loops):
+    '''calculate the final library and object dependencies'''
+    for t in tgt_list:
+        # start with the maximum possible list
+        t.final_libs    = t.direct_libs.union(indirect_libs(bld, t, set(), loops))
+        t.final_objects = t.direct_objects.union(indirect_objects(bld, t, set(), loops))
+
+    for t in tgt_list:
+        # don't depend on ourselves
+        if t.sname in t.final_libs:
+            t.final_libs.remove(t.sname)
+        if t.sname in t.final_objects:
+            t.final_objects.remove(t.sname)
+
+    # handle any non-shared binaries
+    for t in tgt_list:
+        if t.samba_type == 'BINARY' and bld.NONSHARED_BINARY(t.sname):
+            subsystem_list = LOCAL_CACHE(bld, 'INIT_FUNCTIONS')
+            targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+            # replace lib deps with objlist deps
+            for l in t.final_libs:
+                objname = l + '.objlist'
+                t2 = bld.get_tgen_by_name(objname)
+                if t2 is None:
+                    Logs.error('ERROR: subsystem %s not found' % objname)
+                    sys.exit(1)
+                t.final_objects.add(objname)
+                t.final_objects = t.final_objects.union(extended_objects(bld, t2, set()))
+                if l in subsystem_list:
+                    # its a subsystem - we also need the contents of any modules
+                    for d in subsystem_list[l]:
+                        module_name = d['TARGET']
+                        if targets[module_name] == 'LIBRARY':
+                            objname = module_name + '.objlist'
+                        elif targets[module_name] == 'SUBSYSTEM':
+                            objname = module_name
+                        else:
+                            continue
+                        t2 = bld.get_tgen_by_name(objname)
+                        if t2 is None:
+                            Logs.error('ERROR: subsystem %s not found' % objname)
+                            sys.exit(1)
+                        t.final_objects.add(objname)
+                        t.final_objects = t.final_objects.union(extended_objects(bld, t2, set()))
+            t.final_libs = set()
+
+    # find any library loops
+    for t in tgt_list:
+        if t.samba_type in ['LIBRARY', 'PYTHON']:
+            for l in t.final_libs.copy():
+                t2 = bld.get_tgen_by_name(l)
+                if t.sname in t2.final_libs:
+                    if getattr(bld.env, "ALLOW_CIRCULAR_LIB_DEPENDENCIES", False):
+                        # we could break this in either direction. If one of the libraries
+                        # has a version number, and will this be distributed publicly, then
+                        # we should make it the lower level library in the DAG
+                        Logs.warn('deps: removing library loop %s from %s' % (t.sname, t2.sname))
+                        dependency_loop(loops, t, t2.sname)
+                        t2.final_libs.remove(t.sname)
+                    else:
+                        Logs.error('ERROR: circular library dependency between %s and %s'
+                            % (t.sname, t2.sname))
+                        show_library_loop(bld, t.sname, t2.sname, t.sname, set())
+                        show_library_loop(bld, t2.sname, t.sname, t2.sname, set())
+                        sys.exit(1)
+
+    for loop in loops:
+        debug('deps: Found dependency loops for target %s : %s', loop, loops[loop])
+
+    # we now need to make corrections for any library loops we broke up
+    # any target that depended on the target of the loop and doesn't
+    # depend on the source of the loop needs to get the loop source added
+    for type in ['BINARY','PYTHON','LIBRARY','PLUGIN','BINARY']:
+        for t in tgt_list:
+            if t.samba_type != type: continue
+            for loop in loops:
+                if loop in t.final_libs:
+                    diff = loops[loop].difference(t.final_libs)
+                    if t.sname in diff:
+                        diff.remove(t.sname)
+                    if t.sname in diff:
+                        diff.remove(t.sname)
+                    # make sure we don't recreate the loop again!
+                    for d in diff.copy():
+                        t2 = bld.get_tgen_by_name(d)
+                        if t2.samba_type == 'LIBRARY':
+                            if t.sname in t2.final_libs:
+                                debug('deps: removing expansion %s from %s', d, t.sname)
+                                diff.remove(d)
+                    if diff:
+                        debug('deps: Expanded target %s by loop %s libraries (loop %s) %s', t.sname, loop,
+                              loops[loop], diff)
+                        t.final_libs = t.final_libs.union(diff)
+
+    # remove objects that are also available in linked libs
+    count = 0
+    while reduce_objects(bld, tgt_list):
+        count += 1
+        if count > 100:
+            Logs.warn("WARNING: Unable to remove all inter-target object duplicates")
+            break
+    debug('deps: Object reduction took %u iterations', count)
+
+    # add in any syslib dependencies
+    for t in tgt_list:
+        if not t.samba_type in ['BINARY','PYTHON','LIBRARY','PLUGIN','SUBSYSTEM','BUILTIN']:
+            continue
+        syslibs = set()
+        for d in t.final_objects:
+            t2 = bld.get_tgen_by_name(d)
+            syslibs = syslibs.union(t2.direct_syslibs)
+        # this adds the indirect syslibs as well, which may not be needed
+        # depending on the linker flags
+        for d in t.final_libs:
+            t2 = bld.get_tgen_by_name(d)
+            syslibs = syslibs.union(t2.direct_syslibs)
+        t.final_syslibs = syslibs
+
+
+    # find any unresolved library loops
+    lib_loop_error = False
+    for t in tgt_list:
+        if t.samba_type in ['LIBRARY', 'PLUGIN', 'PYTHON']:
+            for l in t.final_libs.copy():
+                t2 = bld.get_tgen_by_name(l)
+                if t.sname in t2.final_libs:
+                    Logs.error('ERROR: Unresolved library loop %s from %s' % (t.sname, t2.sname))
+                    lib_loop_error = True
+    if lib_loop_error:
+        sys.exit(1)
+
+    debug('deps: removed duplicate dependencies')
+
+
+def show_dependencies(bld, target, seen):
+    '''recursively show the dependencies of target'''
+
+    if target in seen:
+        return
+
+    t = bld.get_tgen_by_name(target)
+    if t is None:
+        Logs.error("ERROR: Unable to find target '%s'" % target)
+        sys.exit(1)
+
+    Logs.info('%s(OBJECTS): %s' % (target, t.direct_objects))
+    Logs.info('%s(LIBS): %s' % (target, t.direct_libs))
+    Logs.info('%s(SYSLIBS): %s' % (target, t.direct_syslibs))
+
+    seen.add(target)
+
+    for t2 in t.direct_objects:
+        show_dependencies(bld, t2, seen)
+
+
+def show_object_duplicates(bld, tgt_list):
+    '''show a list of object files that are included in more than
+    one library or binary'''
+
+    targets = LOCAL_CACHE(bld, 'TARGET_TYPE')
+
+    used_by = {}
+
+    Logs.info("showing duplicate objects")
+
+    for t in tgt_list:
+        if not targets[t.sname] in [ 'LIBRARY', 'PYTHON' ]:
+            continue
+        for n in getattr(t, 'final_objects', set()):
+            t2 = bld.get_tgen_by_name(n)
+            if not n in used_by:
+                used_by[n] = set()
+            used_by[n].add(t.sname)
+
+    for n in used_by:
+        if len(used_by[n]) > 1:
+            Logs.info("target '%s' is used by %s" % (n, used_by[n]))
+
+    Logs.info("showing indirect dependency counts (sorted by count)")
+
+    def indirect_count(t):
+        return len(t.indirect_objects)
+
+    sorted_list = sorted(tgt_list, key=indirect_count, reverse=True)
+    for t in sorted_list:
+        if len(t.indirect_objects) > 1:
+            Logs.info("%s depends on %u indirect objects" % (t.sname, len(t.indirect_objects)))
+
+
+######################################################################
+# this provides a way to save our dependency calculations between runs
+savedeps_version = 3
+savedeps_inputs  = ['samba_deps', 'samba_includes', 'local_include', 'local_include_first', 'samba_cflags',
+                    'source', 'grouping_library', 'samba_ldflags', 'allow_undefined_symbols',
+                    'use_global_deps', 'global_include' ]
+savedeps_outputs = ['uselib', 'uselib_local', 'add_objects', 'includes',
+                    'cflags', 'ldflags', 'samba_deps_extended', 'final_libs']
+savedeps_outenv  = ['INC_PATHS']
+savedeps_envvars = ['NONSHARED_BINARIES', 'GLOBAL_DEPENDENCIES', 'EXTRA_CFLAGS', 'EXTRA_LDFLAGS', 'EXTRA_INCLUDES' ]
+savedeps_caches  = ['GLOBAL_DEPENDENCIES', 'TARGET_TYPE', 'INIT_FUNCTIONS', 'SYSLIB_DEPS']
+savedeps_files   = ['buildtools/wafsamba/samba_deps.py']
+
+def save_samba_deps(bld, tgt_list):
+    '''save the dependency calculations between builds, to make
+       further builds faster'''
+    denv = ConfigSet.ConfigSet()
+
+    denv.version = savedeps_version
+    denv.savedeps_inputs = savedeps_inputs
+    denv.savedeps_outputs = savedeps_outputs
+    denv.input = {}
+    denv.output = {}
+    denv.outenv = {}
+    denv.caches = {}
+    denv.envvar = {}
+    denv.files  = {}
+
+    for f in savedeps_files:
+        denv.files[f] = os.stat(os.path.join(bld.srcnode.abspath(), f)).st_mtime
+
+    for c in savedeps_caches:
+        denv.caches[c] = LOCAL_CACHE(bld, c)
+
+    for e in savedeps_envvars:
+        denv.envvar[e] = bld.env[e]
+
+    for t in tgt_list:
+        # save all the input attributes for each target
+        tdeps = {}
+        for attr in savedeps_inputs:
+            v = getattr(t, attr, None)
+            if v is not None:
+                tdeps[attr] = v
+        if tdeps != {}:
+            denv.input[t.sname] = tdeps
+
+        # save all the output attributes for each target
+        tdeps = {}
+        for attr in savedeps_outputs:
+            v = getattr(t, attr, None)
+            if v is not None:
+                tdeps[attr] = v
+        if tdeps != {}:
+            denv.output[t.sname] = tdeps
+
+        tdeps = {}
+        for attr in savedeps_outenv:
+            if attr in t.env:
+                tdeps[attr] = t.env[attr]
+        if tdeps != {}:
+            denv.outenv[t.sname] = tdeps
+
+    depsfile = os.path.join(bld.cache_dir, "sambadeps")
+    denv.store_fast(depsfile)
+
+
+
+def load_samba_deps(bld, tgt_list):
+    '''load a previous set of build dependencies if possible'''
+    depsfile = os.path.join(bld.cache_dir, "sambadeps")
+    denv = ConfigSet.ConfigSet()
+    try:
+        debug('deps: checking saved dependencies')
+        denv.load_fast(depsfile)
+        if (denv.version != savedeps_version or
+            denv.savedeps_inputs != savedeps_inputs or
+            denv.savedeps_outputs != savedeps_outputs):
+            return False
+    except Exception:
+        return False
+
+    # check if critical files have changed
+    for f in savedeps_files:
+        if f not in denv.files:
+            return False
+        if denv.files[f] != os.stat(os.path.join(bld.srcnode.abspath(), f)).st_mtime:
+            return False
+
+    # check if caches are the same
+    for c in savedeps_caches:
+        if c not in denv.caches or denv.caches[c] != LOCAL_CACHE(bld, c):
+            return False
+
+    # check if caches are the same
+    for e in savedeps_envvars:
+        if e not in denv.envvar or denv.envvar[e] != bld.env[e]:
+            return False
+
+    # check inputs are the same
+    for t in tgt_list:
+        tdeps = {}
+        for attr in savedeps_inputs:
+            v = getattr(t, attr, None)
+            if v is not None:
+                tdeps[attr] = v
+        if t.sname in denv.input:
+            olddeps = denv.input[t.sname]
+        else:
+            olddeps = {}
+        if tdeps != olddeps:
+            #print '%s: \ntdeps=%s \nodeps=%s' % (t.sname, tdeps, olddeps)
+            return False
+
+    # put outputs in place
+    for t in tgt_list:
+        if not t.sname in denv.output: continue
+        tdeps = denv.output[t.sname]
+        for a in tdeps:
+            setattr(t, a, tdeps[a])
+
+    # put output env vars in place
+    for t in tgt_list:
+        if not t.sname in denv.outenv: continue
+        tdeps = denv.outenv[t.sname]
+        for a in tdeps:
+            t.env[a] = tdeps[a]
+
+    debug('deps: loaded saved dependencies')
+    return True
+
+
+def generate_clangdb(bld):
+    classes = []
+    for x in ('c', 'cxx'):
+        cls = Task.classes.get(x)
+        if cls:
+            classes.append(cls)
+    task_classes = tuple(classes)
+
+    tasks = []
+    for g in bld.groups:
+        for tg in g:
+            if isinstance(tg, Task.Task):
+                lst = [tg]
+            else:
+                lst = tg.tasks
+            for task in lst:
+                try:
+                    task.last_cmd
+                except AttributeError:
+                    continue
+                if isinstance(task, task_classes):
+                    tasks.append(task)
+    if len(tasks) == 0:
+        return
+
+    database_file = bld.bldnode.make_node('compile_commands.json')
+    Logs.info('Build commands will be stored in %s',
+              database_file.path_from(bld.path))
+    try:
+        root = database_file.read_json()
+    except IOError:
+        root = []
+    clang_db = dict((x['file'], x) for x in root)
+    for task in tasks:
+        f_node = task.inputs[0]
+        cmd = task.last_cmd
+        filename = f_node.path_from(task.get_cwd())
+        entry = {
+            "directory": task.get_cwd().abspath(),
+            "arguments": cmd,
+            "file": filename,
+        }
+        clang_db[filename] = entry
+    root = list(clang_db.values())
+    database_file.write_json(root)
+
+
+def check_project_rules(bld):
+    '''check the project rules - ensuring the targets are sane'''
+
+    loops = {}
+    inc_loops = {}
+
+    tgt_list = get_tgt_list(bld)
+
+    add_samba_attributes(bld, tgt_list)
+
+    force_project_rules = (Options.options.SHOWDEPS or
+                           Options.options.SHOW_DUPLICATES)
+
+    if not force_project_rules and load_samba_deps(bld, tgt_list):
+        return
+
+    timer = Utils.Timer()
+
+    bld.new_rules = True
+    Logs.info("Checking project rules ...")
+
+    debug('deps: project rules checking started')
+
+    replace_builtin_subsystem_deps(bld, tgt_list)
+
+    debug("deps: replace_builtin_subsystem_deps: %s" % str(timer))
+
+    expand_subsystem_deps(bld)
+
+    debug("deps: expand_subsystem_deps: %s" % str(timer))
+
+    replace_grouping_libraries(bld, tgt_list)
+
+    debug("deps: replace_grouping_libraries: %s" % str(timer))
+
+    build_direct_deps(bld, tgt_list)
+
+    debug("deps: build_direct_deps: %s" % str(timer))
+
+    break_dependency_loops(bld, tgt_list)
+
+    debug("deps: break_dependency_loops: %s" % str(timer))
+
+    if Options.options.SHOWDEPS:
+            show_dependencies(bld, Options.options.SHOWDEPS, set())
+
+    calculate_final_deps(bld, tgt_list, loops)
+
+    debug("deps: calculate_final_deps: %s" % str(timer))
+
+    if Options.options.SHOW_DUPLICATES:
+            show_object_duplicates(bld, tgt_list)
+
+    # run the various attribute generators
+    for f in [ build_dependencies, build_includes, add_init_functions ]:
+        debug('deps: project rules checking %s', f)
+        for t in tgt_list: f(t)
+        debug("deps: %s: %s" % (f, str(timer)))
+
+    debug('deps: project rules stage1 completed')
+
+    if not check_duplicate_sources(bld, tgt_list):
+        Logs.error("Duplicate sources present - aborting")
+        sys.exit(1)
+
+    debug("deps: check_duplicate_sources: %s" % str(timer))
+
+    if not bld.check_group_ordering(tgt_list):
+        Logs.error("Bad group ordering - aborting")
+        sys.exit(1)
+
+    debug("deps: check_group_ordering: %s" % str(timer))
+
+    show_final_deps(bld, tgt_list)
+
+    debug("deps: show_final_deps: %s" % str(timer))
+
+    debug('deps: project rules checking completed - %u targets checked',
+          len(tgt_list))
+
+    if not bld.is_install:
+        save_samba_deps(bld, tgt_list)
+
+    debug("deps: save_samba_deps: %s" % str(timer))
+
+    Logs.info("Project rules pass")
+
+    if bld.cmd == 'build':
+        Task.Task.keep_last_cmd = True
+        bld.add_post_fun(generate_clangdb)
+
+
+def CHECK_PROJECT_RULES(bld):
+    '''enable checking of project targets for sanity'''
+    if bld.env.added_project_rules:
+        return
+    bld.env.added_project_rules = True
+    bld.add_pre_fun(check_project_rules)
+Build.BuildContext.CHECK_PROJECT_RULES = CHECK_PROJECT_RULES
+
+