X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2FSConscript;h=3e9196cd5e7e21cedb8e4804b9106d6bd3bf1cb2;hb=d2fd3b2ec2c265eb9ed3bdcc1db3e4c3feee3846;hp=5ba89381d1eb03ffd1847fac35be4090fac43d14;hpb=0876c822dd25e57e8811ceb31f67a3536c9855b0;p=gem5.git

diff --git a/src/SConscript b/src/SConscript
old mode 100644
new mode 100755
index 5ba89381d..3e9196cd5
--- a/src/SConscript
+++ b/src/SConscript
@@ -29,6 +29,7 @@
 # Authors: Nathan Binkert
 
 import array
+import bisect
 import imp
 import marshal
 import os
@@ -40,7 +41,7 @@ from os.path import basename, dirname, exists, isdir, isfile, join as joinpath
 
 import SCons
 
-# This file defines how to build a particular configuration of M5
+# This file defines how to build a particular configuration of gem5
 # based on variable settings in the 'env' build environment.
 
 Import('*')
@@ -48,154 +49,254 @@ Import('*')
 # Children need to see the environment
 Export('env')
 
-build_env = dict([(opt, env[opt]) for opt in env.ExportOptions])
+build_env = [(opt, env[opt]) for opt in export_vars]
 
-def sort_list(_list):
-    """return a sorted copy of '_list'"""
-    if isinstance(_list, list):
-        _list = _list[:]
-    else:
-        _list = list(_list)
-    _list.sort()
-    return _list
+from m5.util import code_formatter, compareVersions
+
+########################################################################
+# Code for adding source files of various types
+#
+# When specifying a source file of some type, a set of guards can be
+# specified for that file.  When get() is used to find the files, if
+# get specifies a set of filters, only files that match those filters
+# will be accepted (unspecified filters on files are assumed to be
+# false).  Current filters are:
+#     main -- specifies the gem5 main() function
+#     skip_lib -- do not put this file into the gem5 library
+#     <unittest> -- unit tests use filters based on the unit test name
+#
+# A parent can now be specified for a source file and default filter
+# values will be retrieved recursively from parents (children override
+# parents).
+#
+class SourceMeta(type):
+    '''Meta class for source files that keeps track of all files of a
+    particular type and has a get function for finding all functions
+    of a certain type that match a set of guards'''
+    def __init__(cls, name, bases, dict):
+        super(SourceMeta, cls).__init__(name, bases, dict)
+        cls.all = []
+        
+    def get(cls, **guards):
+        '''Find all files that match the specified guards.  If a source
+        file does not specify a flag, the default is False'''
+        for src in cls.all:
+            for flag,value in guards.iteritems():
+                # if the flag is found and has a different value, skip
+                # this file
+                if src.all_guards.get(flag, False) != value:
+                    break
+            else:
+                yield src
+
+class SourceFile(object):
+    '''Base object that encapsulates the notion of a source file.
+    This includes, the source node, target node, various manipulations
+    of those.  A source file also specifies a set of guards which
+    describing which builds the source file applies to.  A parent can
+    also be specified to get default guards from'''
+    __metaclass__ = SourceMeta
+    def __init__(self, source, parent=None, **guards):
+        self.guards = guards
+        self.parent = parent
+
+        tnode = source
+        if not isinstance(source, SCons.Node.FS.File):
+            tnode = File(source)
+
+        self.tnode = tnode
+        self.snode = tnode.srcnode()
+
+        for base in type(self).__mro__:
+            if issubclass(base, SourceFile):
+                base.all.append(self)
+
+    @property
+    def filename(self):
+        return str(self.tnode)
+
+    @property
+    def dirname(self):
+        return dirname(self.filename)
+
+    @property
+    def basename(self):
+        return basename(self.filename)
+
+    @property
+    def extname(self):
+        index = self.basename.rfind('.')
+        if index <= 0:
+            # dot files aren't extensions
+            return self.basename, None
+
+        return self.basename[:index], self.basename[index+1:]
+
+    @property
+    def all_guards(self):
+        '''find all guards for this object getting default values
+        recursively from its parents'''
+        guards = {}
+        if self.parent:
+            guards.update(self.parent.guards)
+        guards.update(self.guards)
+        return guards
+
+    def __lt__(self, other): return self.filename < other.filename
+    def __le__(self, other): return self.filename <= other.filename
+    def __gt__(self, other): return self.filename > other.filename
+    def __ge__(self, other): return self.filename >= other.filename
+    def __eq__(self, other): return self.filename == other.filename
+    def __ne__(self, other): return self.filename != other.filename
+        
+class Source(SourceFile):
+    '''Add a c/c++ source file to the build'''
+    def __init__(self, source, Werror=True, swig=False, **guards):
+        '''specify the source file, and any guards'''
+        super(Source, self).__init__(source, **guards)
+
+        self.Werror = Werror
+        self.swig = swig
 
-class PySourceFile(object):
+class PySource(SourceFile):
+    '''Add a python source file to the named package'''
     invalid_sym_char = re.compile('[^A-z0-9_]')
-    def __init__(self, package, tnode):
-        snode = tnode.srcnode()
-        filename = str(tnode)
-        pyname = basename(filename)
-        assert pyname.endswith('.py')
-        name = pyname[:-3]
+    modules = {}
+    tnodes = {}
+    symnames = {}
+    
+    def __init__(self, package, source, **guards):
+        '''specify the python package, the source file, and any guards'''
+        super(PySource, self).__init__(source, **guards)
+
+        modname,ext = self.extname
+        assert ext == 'py'
+
         if package:
             path = package.split('.')
         else:
             path = []
 
         modpath = path[:]
-        if name != '__init__':
-            modpath += [name]
+        if modname != '__init__':
+            modpath += [ modname ]
         modpath = '.'.join(modpath)
 
-        arcpath = path + [ pyname ]
-        arcname = joinpath(*arcpath)
+        arcpath = path + [ self.basename ]
+        abspath = self.snode.abspath
+        if not exists(abspath):
+            abspath = self.tnode.abspath
 
-        debugname = snode.abspath
-        if not exists(debugname):
-            debugname = tnode.abspath
-
-        self.tnode = tnode
-        self.snode = snode
-        self.pyname = pyname
         self.package = package
+        self.modname = modname
         self.modpath = modpath
-        self.arcname = arcname
-        self.debugname = debugname
-        self.compiled = File(filename + 'c')
-        self.assembly = File(filename + '.s')
-        self.symname = "PyEMB_" + self.invalid_sym_char.sub('_', modpath)
-        
+        self.arcname = joinpath(*arcpath)
+        self.abspath = abspath
+        self.compiled = File(self.filename + 'c')
+        self.cpp = File(self.filename + '.cc')
+        self.symname = PySource.invalid_sym_char.sub('_', modpath)
 
-########################################################################
-# Code for adding source files of various types
-#
-cc_lib_sources = []
-def Source(source):
-    '''Add a source file to the libm5 build'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
+        PySource.modules[modpath] = self
+        PySource.tnodes[self.tnode] = self
+        PySource.symnames[self.symname] = self
 
-    cc_lib_sources.append(source)
+class SimObject(PySource):
+    '''Add a SimObject python file as a python source object and add
+    it to a list of sim object modules'''
 
-cc_bin_sources = []
-def BinSource(source):
-    '''Add a source file to the m5 binary build'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
+    fixed = False
+    modnames = []
 
-    cc_bin_sources.append(source)
+    def __init__(self, source, **guards):
+        '''Specify the source file and any guards (automatically in
+        the m5.objects package)'''
+        super(SimObject, self).__init__('m5.objects', source, **guards)
+        if self.fixed:
+            raise AttributeError, "Too late to call SimObject now."
 
-py_sources = []
-def PySource(package, source):
-    '''Add a python source file to the named package'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
+        bisect.insort_right(SimObject.modnames, self.modname)
 
-    source = PySourceFile(package, source)
-    py_sources.append(source)
+class SwigSource(SourceFile):
+    '''Add a swig file to build'''
 
-sim_objects_fixed = False
-sim_object_modfiles = set()
-def SimObject(source):
-    '''Add a SimObject python file as a python source object and add
-    it to a list of sim object modules'''
+    def __init__(self, package, source, **guards):
+        '''Specify the python package, the source file, and any guards'''
+        super(SwigSource, self).__init__(source, **guards)
 
-    if sim_objects_fixed:
-        raise AttributeError, "Too late to call SimObject now."
+        modname,ext = self.extname
+        assert ext == 'i'
 
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
+        self.module = modname
+        cc_file = joinpath(self.dirname, modname + '_wrap.cc')
+        py_file = joinpath(self.dirname, modname + '.py')
 
-    PySource('m5.objects', source)
-    modfile = basename(str(source))
-    assert modfile.endswith('.py')
-    modname = modfile[:-3]
-    sim_object_modfiles.add(modname)
+        self.cc_source = Source(cc_file, swig=True, parent=self)
+        self.py_source = PySource(package, py_file, parent=self)
 
-swig_sources = []
-def SwigSource(package, source):
-    '''Add a swig file to build'''
-    if not isinstance(source, SCons.Node.FS.File):
-        source = File(source)
-    val = source,package
-    swig_sources.append(val)
-
-unit_tests = []
-def UnitTest(target, sources):
-    if not isinstance(sources, (list, tuple)):
-        sources = [ sources ]
-    
-    srcs = []
-    for source in sources:
-        if not isinstance(source, SCons.Node.FS.File):
-            source = File(source)
-        srcs.append(source)
-            
-    unit_tests.append((target, srcs))
+class ProtoBuf(SourceFile):
+    '''Add a Protocol Buffer to build'''
+
+    def __init__(self, source, **guards):
+        '''Specify the source file, and any guards'''
+        super(ProtoBuf, self).__init__(source, **guards)
+
+        # Get the file name and the extension
+        modname,ext = self.extname
+        assert ext == 'proto'
+
+        # Currently, we stick to generating the C++ headers, so we
+        # only need to track the source and header.
+        self.cc_file = File(joinpath(self.dirname, modname + '.pb.cc'))
+        self.hh_file = File(joinpath(self.dirname, modname + '.pb.h'))
+
+class UnitTest(object):
+    '''Create a UnitTest'''
+
+    all = []
+    def __init__(self, target, *sources, **kwargs):
+        '''Specify the target name and any sources.  Sources that are
+        not SourceFiles are evalued with Source().  All files are
+        guarded with a guard of the same name as the UnitTest
+        target.'''
+
+        srcs = []
+        for src in sources:
+            if not isinstance(src, SourceFile):
+                src = Source(src, skip_lib=True)
+            src.guards[target] = True
+            srcs.append(src)
+
+        self.sources = srcs
+        self.target = target
+        self.main = kwargs.get('main', False)
+        UnitTest.all.append(self)
 
 # Children should have access
 Export('Source')
-Export('BinSource')
 Export('PySource')
 Export('SimObject')
 Export('SwigSource')
+Export('ProtoBuf')
 Export('UnitTest')
 
 ########################################################################
 #
-# Trace Flags
+# Debug Flags
 #
-trace_flags = {}
-def TraceFlag(name, desc=None):
-    if name in trace_flags:
+debug_flags = {}
+def DebugFlag(name, desc=None):
+    if name in debug_flags:
         raise AttributeError, "Flag %s already specified" % name
-    trace_flags[name] = (name, (), desc)
+    debug_flags[name] = (name, (), desc)
 
 def CompoundFlag(name, flags, desc=None):
-    if name in trace_flags:
+    if name in debug_flags:
         raise AttributeError, "Flag %s already specified" % name
 
     compound = tuple(flags)
-    for flag in compound:
-        if flag not in trace_flags:
-            raise AttributeError, "Trace flag %s not found" % flag
-        if trace_flags[flag][1]:
-            raise AttributeError, \
-                "Compound flag can't point to another compound flag"
-
-    trace_flags[name] = (name, compound, desc)
+    debug_flags[name] = (name, compound, desc)
 
-Export('TraceFlag')
+Export('DebugFlag')
 Export('CompoundFlag')
 
 ########################################################################
@@ -212,11 +313,8 @@ env.Append(CPPPATH=Dir('.'))
 for extra_dir in extras_dir_list:
     env.Append(CPPPATH=Dir(extra_dir))
 
-# Add a flag defining what THE_ISA should be for all compilation
-env.Append(CPPDEFINES=[('THE_ISA','%s_ISA' % env['TARGET_ISA'].upper())])
-
 # Workaround for bug in SCons version > 0.97d20071212
-# Scons bug id: 2006 M5 Bug id: 308 
+# Scons bug id: 2006 gem5 Bug id: 308
 for root, dirs, files in os.walk(base_dir, topdown=True):
     Dir(root[len(base_dir) + 1:])
 
@@ -233,23 +331,62 @@ for root, dirs, files in os.walk(base_dir, topdown=True):
 
     if 'SConscript' in files:
         build_dir = joinpath(env['BUILDDIR'], root[len(base_dir) + 1:])
-        SConscript(joinpath(root, 'SConscript'), build_dir=build_dir)
+        SConscript(joinpath(root, 'SConscript'), variant_dir=build_dir)
 
 for extra_dir in extras_dir_list:
     prefix_len = len(dirname(extra_dir)) + 1
     for root, dirs, files in os.walk(extra_dir, topdown=True):
+        # if build lives in the extras directory, don't walk down it
+        if 'build' in dirs:
+            dirs.remove('build')
+
         if 'SConscript' in files:
             build_dir = joinpath(env['BUILDDIR'], root[prefix_len:])
-            SConscript(joinpath(root, 'SConscript'), build_dir=build_dir)
+            SConscript(joinpath(root, 'SConscript'), variant_dir=build_dir)
 
-for opt in env.ExportOptions:
+for opt in export_vars:
     env.ConfigFile(opt)
 
+def makeTheISA(source, target, env):
+    isas = [ src.get_contents() for src in source ]
+    target_isa = env['TARGET_ISA']
+    def define(isa):
+        return isa.upper() + '_ISA'
+    
+    def namespace(isa):
+        return isa[0].upper() + isa[1:].lower() + 'ISA' 
+
+
+    code = code_formatter()
+    code('''\
+#ifndef __CONFIG_THE_ISA_HH__
+#define __CONFIG_THE_ISA_HH__
+
+''')
+
+    for i,isa in enumerate(isas):
+        code('#define $0 $1', define(isa), i + 1)
+
+    code('''
+
+#define THE_ISA ${{define(target_isa)}}
+#define TheISA ${{namespace(target_isa)}}
+#define THE_ISA_STR "${{target_isa}}"
+
+#endif // __CONFIG_THE_ISA_HH__''')
+
+    code.write(str(target[0]))
+
+env.Command('config/the_isa.hh', map(Value, all_isa_list),
+            MakeAction(makeTheISA, Transform("CFG ISA", 0)))
+
 ########################################################################
 #
 # Prevent any SimObjects from being added after this point, they
 # should all have been added in the SConscripts above
 #
+SimObject.fixed = True
+
 class DictImporter(object):
     '''This importer takes a dictionary of arbitrary module names that
     map to arbitrary filenames.'''
@@ -267,7 +404,7 @@ class DictImporter(object):
         self.installed = set()
 
     def find_module(self, fullname, path):
-        if fullname == 'defines':
+        if fullname == 'm5.defines':
             return self
 
         if fullname == 'm5.objects':
@@ -276,7 +413,8 @@ class DictImporter(object):
         if fullname.startswith('m5.internal'):
             return None
 
-        if fullname in self.modules and exists(self.modules[fullname]):
+        source = self.modules.get(fullname, None)
+        if source is not None and fullname.startswith('m5.objects'):
             return self
 
         return None
@@ -291,38 +429,36 @@ class DictImporter(object):
             mod.__path__ = fullname.split('.')
             return mod
 
-        if fullname == 'defines':
-            mod.__dict__['buildEnv'] = build_env
+        if fullname == 'm5.defines':
+            mod.__dict__['buildEnv'] = m5.util.SmartDict(build_env)
             return mod
 
-        srcfile = self.modules[fullname]
-        if basename(srcfile) == '__init__.py':
-            mod.__path__ = fullname.split('.')
-        mod.__file__ = srcfile
+        source = self.modules[fullname]
+        if source.modname == '__init__':
+            mod.__path__ = source.modpath
+        mod.__file__ = source.abspath
 
-        exec file(srcfile, 'r') in mod.__dict__
+        exec file(source.abspath, 'r') in mod.__dict__
 
         return mod
 
-py_modules = {}
-for source in py_sources:
-    py_modules[source.modpath] = source.snode.abspath
+import m5.SimObject
+import m5.params
+from m5.util import code_formatter
+
+m5.SimObject.clear()
+m5.params.clear()
 
 # install the python importer so we can grab stuff from the source
 # tree itself.  We can't have SimObjects added after this point or
 # else we won't know about them for the rest of the stuff.
-sim_objects_fixed = True
-importer = DictImporter(py_modules)
+importer = DictImporter(PySource.modules)
 sys.meta_path[0:0] = [ importer ]
 
-import m5
-
 # import all sim objects so we can populate the all_objects list
 # make sure that we're working with a list, then let's sort it
-sim_objects = list(sim_object_modfiles)
-sim_objects.sort()
-for simobj in sim_objects:
-    exec('from m5.objects import %s' % simobj)
+for modname in SimObject.modnames:
+    exec('from m5.objects import %s' % modname)
 
 # we need to unload all of the currently imported modules so that they
 # will be re-imported the next time the sconscript is run
@@ -332,615 +468,402 @@ sys.meta_path.remove(importer)
 sim_objects = m5.SimObject.allClasses
 all_enums = m5.params.allEnums
 
-all_params = {}
-for name,obj in sim_objects.iteritems():
+if m5.SimObject.noCxxHeader:
+    print >> sys.stderr, \
+        "warning: At least one SimObject lacks a header specification. " \
+        "This can cause unexpected results in the generated SWIG " \
+        "wrappers."
+
+# Find param types that need to be explicitly wrapped with swig.
+# These will be recognized because the ParamDesc will have a
+# swig_decl() method.  Most param types are based on types that don't
+# need this, either because they're based on native types (like Int)
+# or because they're SimObjects (which get swigged independently).
+# For now the only things handled here are VectorParam types.
+params_to_swig = {}
+for name,obj in sorted(sim_objects.iteritems()):
     for param in obj._params.local.values():
+        # load the ptype attribute now because it depends on the
+        # current version of SimObject.allClasses, but when scons
+        # actually uses the value, all versions of
+        # SimObject.allClasses will have been loaded
+        param.ptype
+
         if not hasattr(param, 'swig_decl'):
             continue
         pname = param.ptype_str
-        if pname not in all_params:
-            all_params[pname] = param
+        if pname not in params_to_swig:
+            params_to_swig[pname] = param
 
 ########################################################################
 #
 # calculate extra dependencies
 #
 module_depends = ["m5", "m5.SimObject", "m5.params"]
-depends = [ File(py_modules[dep]) for dep in module_depends ]
+depends = [ PySource.modules[dep].snode for dep in module_depends ]
 
 ########################################################################
 #
 # Commands for the basic automatically generated python files
 #
 
-scons_dir = str(SCons.Node.FS.default_fs.SConstruct_dir)
-
-hg_info = ("Unknown", "Unknown", "Unknown")
-hg_demandimport = False
-try:
-    if not exists(scons_dir) or not isdir(scons_dir) or \
-           not exists(joinpath(scons_dir, ".hg")):
-        raise ValueError(".hg directory not found")
-
-    import mercurial.demandimport, mercurial.hg, mercurial.ui
-    import mercurial.util, mercurial.node
-    hg_demandimport = True
-
-    repo = mercurial.hg.repository(mercurial.ui.ui(), scons_dir)
-    rev = mercurial.node.nullrev + repo.changelog.count()
-    changenode = repo.changelog.node(rev)
-    changes = repo.changelog.read(changenode)
-    id = mercurial.node.hex(changenode)
-    date = mercurial.util.datestr(changes[2])
-
-    hg_info = (rev, id, date)
-except ImportError, e:
-    print "Mercurial not found"
-except ValueError, e:
-    print e
-except Exception, e:
-    print "Other mercurial exception: %s" % e
-
-if hg_demandimport:
-    mercurial.demandimport.disable()
-
 # Generate Python file containing a dict specifying the current
-# build_env flags.
+# buildEnv flags.
 def makeDefinesPyFile(target, source, env):
-    f = file(str(target[0]), 'w')
-    build_env, hg_info = [ x.get_contents() for x in source ]
-    print >>f, "buildEnv = %s" % build_env
-    print >>f, "hgRev, hgId, hgDate = %s" % hg_info
-    f.close()
-
-defines_info = [ Value(build_env), Value(hg_info) ]
+    build_env = source[0].get_contents()
+
+    code = code_formatter()
+    code("""
+import m5.internal
+import m5.util
+
+buildEnv = m5.util.SmartDict($build_env)
+
+compileDate = m5.internal.core.compileDate
+_globals = globals()
+for key,val in m5.internal.core.__dict__.iteritems():
+    if key.startswith('flag_'):
+        flag = key[5:]
+        _globals[flag] = val
+del _globals
+""")
+    code.write(target[0].abspath)
+
+defines_info = Value(build_env)
 # Generate a file with all of the compile options in it
-env.Command('python/m5/defines.py', defines_info, makeDefinesPyFile)
+env.Command('python/m5/defines.py', defines_info,
+            MakeAction(makeDefinesPyFile, Transform("DEFINES", 0)))
 PySource('m5', 'python/m5/defines.py')
 
 # Generate python file containing info about the M5 source code
 def makeInfoPyFile(target, source, env):
-    f = file(str(target[0]), 'w')
+    code = code_formatter()
     for src in source:
         data = ''.join(file(src.srcnode().abspath, 'r').xreadlines())
-        print >>f, "%s = %s" % (src, repr(data))
-    f.close()
+        code('$src = ${{repr(data)}}')
+    code.write(str(target[0]))
 
 # Generate a file that wraps the basic top level files
 env.Command('python/m5/info.py',
-            [ '#/AUTHORS', '#/LICENSE', '#/README', '#/RELEASE_NOTES' ],
-            makeInfoPyFile)
+            [ '#/COPYING', '#/LICENSE', '#/README', ],
+            MakeAction(makeInfoPyFile, Transform("INFO")))
 PySource('m5', 'python/m5/info.py')
 
-# Generate the __init__.py file for m5.objects
-def makeObjectsInitFile(target, source, env):
-    f = file(str(target[0]), 'w')
-    print >>f, 'from params import *'
-    print >>f, 'from m5.SimObject import *'
-    for module in source:
-        print >>f, 'from %s import *' % module.get_contents()
-    f.close()
-
-# Generate an __init__.py file for the objects package
-env.Command('python/m5/objects/__init__.py',
-            [ Value(o) for o in sort_list(sim_object_modfiles) ],
-            makeObjectsInitFile)
-PySource('m5.objects', 'python/m5/objects/__init__.py')
-
 ########################################################################
 #
 # Create all of the SimObject param headers and enum headers
 #
 
-def createSimObjectParam(target, source, env):
+def createSimObjectParamStruct(target, source, env):
     assert len(target) == 1 and len(source) == 1
 
-    hh_file = file(target[0].abspath, 'w')
     name = str(source[0].get_contents())
     obj = sim_objects[name]
 
-    print >>hh_file, obj.cxx_decl()
+    code = code_formatter()
+    obj.cxx_param_decl(code)
+    code.write(target[0].abspath)
 
-def createSwigParam(target, source, env):
+def createParamSwigWrapper(target, source, env):
     assert len(target) == 1 and len(source) == 1
 
-    i_file = file(target[0].abspath, 'w')
     name = str(source[0].get_contents())
-    param = all_params[name]
+    param = params_to_swig[name]
 
-    for line in param.swig_decl():
-        print >>i_file, line
+    code = code_formatter()
+    param.swig_decl(code)
+    code.write(target[0].abspath)
 
 def createEnumStrings(target, source, env):
     assert len(target) == 1 and len(source) == 1
 
-    cc_file = file(target[0].abspath, 'w')
     name = str(source[0].get_contents())
     obj = all_enums[name]
 
-    print >>cc_file, obj.cxx_def()
-    cc_file.close()
+    code = code_formatter()
+    obj.cxx_def(code)
+    code.write(target[0].abspath)
+
+def createEnumDecls(target, source, env):
+    assert len(target) == 1 and len(source) == 1
+
+    name = str(source[0].get_contents())
+    obj = all_enums[name]
+
+    code = code_formatter()
+    obj.cxx_decl(code)
+    code.write(target[0].abspath)
 
-def createEnumParam(target, source, env):
+def createEnumSwigWrapper(target, source, env):
     assert len(target) == 1 and len(source) == 1
 
-    hh_file = file(target[0].abspath, 'w')
     name = str(source[0].get_contents())
     obj = all_enums[name]
 
-    print >>hh_file, obj.cxx_decl()
+    code = code_formatter()
+    obj.swig_decl(code)
+    code.write(target[0].abspath)
 
-# Generate all of the SimObject param struct header files
+def createSimObjectSwigWrapper(target, source, env):
+    name = source[0].get_contents()
+    obj = sim_objects[name]
+
+    code = code_formatter()
+    obj.swig_decl(code)
+    code.write(target[0].abspath)
+
+# Generate all of the SimObject param C++ struct header files
 params_hh_files = []
-for name,simobj in sim_objects.iteritems():
-    extra_deps = [ File(py_modules[simobj.__module__]) ]
+for name,simobj in sorted(sim_objects.iteritems()):
+    py_source = PySource.modules[simobj.__module__]
+    extra_deps = [ py_source.tnode ]
 
     hh_file = File('params/%s.hh' % name)
     params_hh_files.append(hh_file)
-    env.Command(hh_file, Value(name), createSimObjectParam)
+    env.Command(hh_file, Value(name),
+                MakeAction(createSimObjectParamStruct, Transform("SO PARAM")))
     env.Depends(hh_file, depends + extra_deps)
 
-# Generate any parameter header files needed
+# Generate any needed param SWIG wrapper files
 params_i_files = []
-for name,param in all_params.iteritems():
-    if isinstance(param, m5.params.VectorParamDesc):
-        ext = 'vptype'
-    else:
-        ext = 'ptype'
-
-    i_file = File('params/%s_%s.i' % (name, ext))
+for name,param in params_to_swig.iteritems():
+    i_file = File('python/m5/internal/%s.i' % (param.swig_module_name()))
     params_i_files.append(i_file)
-    env.Command(i_file, Value(name), createSwigParam)
+    env.Command(i_file, Value(name),
+                MakeAction(createParamSwigWrapper, Transform("SW PARAM")))
     env.Depends(i_file, depends)
+    SwigSource('m5.internal', i_file)
 
 # Generate all enum header files
-for name,enum in all_enums.iteritems():
-    extra_deps = [ File(py_modules[enum.__module__]) ]
+for name,enum in sorted(all_enums.iteritems()):
+    py_source = PySource.modules[enum.__module__]
+    extra_deps = [ py_source.tnode ]
 
     cc_file = File('enums/%s.cc' % name)
-    env.Command(cc_file, Value(name), createEnumStrings)
+    env.Command(cc_file, Value(name),
+                MakeAction(createEnumStrings, Transform("ENUM STR")))
     env.Depends(cc_file, depends + extra_deps)
     Source(cc_file)
 
     hh_file = File('enums/%s.hh' % name)
-    env.Command(hh_file, Value(name), createEnumParam)
+    env.Command(hh_file, Value(name),
+                MakeAction(createEnumDecls, Transform("ENUMDECL")))
     env.Depends(hh_file, depends + extra_deps)
 
-# Build the big monolithic swigged params module (wraps all SimObject
-# param structs and enum structs)
-def buildParams(target, source, env):
-    names = [ s.get_contents() for s in source ]
-    objs = [ sim_objects[name] for name in names ]
-    out = file(target[0].abspath, 'w')
-
-    ordered_objs = []
-    obj_seen = set()
-    def order_obj(obj):
-        name = str(obj)
-        if name in obj_seen:
-            return
-
-        obj_seen.add(name)
-        if str(obj) != 'SimObject':
-            order_obj(obj.__bases__[0])
-
-        ordered_objs.append(obj)
-
-    for obj in objs:
-        order_obj(obj)
-
-    enums = set()
-    predecls = []
-    pd_seen = set()
-
-    def add_pds(*pds):
-        for pd in pds:
-            if pd not in pd_seen:
-                predecls.append(pd)
-                pd_seen.add(pd)
-
-    for obj in ordered_objs:
-        params = obj._params.local.values()
-        for param in params:
-            ptype = param.ptype
-            if issubclass(ptype, m5.params.Enum):
-                if ptype not in enums:
-                    enums.add(ptype)
-            pds = param.swig_predecls()
-            if isinstance(pds, (list, tuple)):
-                add_pds(*pds)
-            else:
-                add_pds(pds)
-
-    print >>out, '%module params'
+    i_file = File('python/m5/internal/enum_%s.i' % name)
+    env.Command(i_file, Value(name),
+                MakeAction(createEnumSwigWrapper, Transform("ENUMSWIG")))
+    env.Depends(i_file, depends + extra_deps)
+    SwigSource('m5.internal', i_file)
 
-    print >>out, '%{'
-    for obj in ordered_objs:
-        print >>out, '#include "params/%s.hh"' % obj
-    print >>out, '%}'
-
-    for pd in predecls:
-        print >>out, pd
+# Generate SimObject SWIG wrapper files
+for name,simobj in sim_objects.iteritems():
+    py_source = PySource.modules[simobj.__module__]
+    extra_deps = [ py_source.tnode ]
 
-    enums = list(enums)
-    enums.sort()
-    for enum in enums:
-        print >>out, '%%include "enums/%s.hh"' % enum.__name__
-    print >>out
+    i_file = File('python/m5/internal/param_%s.i' % name)
+    env.Command(i_file, Value(name),
+                MakeAction(createSimObjectSwigWrapper, Transform("SO SWIG")))
+    env.Depends(i_file, depends + extra_deps)
+    SwigSource('m5.internal', i_file)
 
-    for obj in ordered_objs:
-        if obj.swig_objdecls:
-            for decl in obj.swig_objdecls:
-                print >>out, decl
-            continue
+# Generate the main swig init file
+def makeEmbeddedSwigInit(target, source, env):
+    code = code_formatter()
+    module = source[0].get_contents()
+    code('''\
+#include "sim/init.hh"
+
+extern "C" {
+    void init_${module}();
+}
+
+EmbeddedSwig embed_swig_${module}(init_${module});
+''')
+    code.write(str(target[0]))
+    
+# Build all swig modules
+for swig in SwigSource.all:
+    env.Command([swig.cc_source.tnode, swig.py_source.tnode], swig.tnode,
+                MakeAction('$SWIG $SWIGFLAGS -outdir ${TARGETS[1].dir} '
+                '-o ${TARGETS[0]} $SOURCES', Transform("SWIG")))
+    cc_file = str(swig.tnode)
+    init_file = '%s/%s_init.cc' % (dirname(cc_file), basename(cc_file))
+    env.Command(init_file, Value(swig.module),
+                MakeAction(makeEmbeddedSwigInit, Transform("EMBED SW")))
+    Source(init_file, **swig.guards)
+
+# Build all protocol buffers if we have got protoc and protobuf available
+if env['HAVE_PROTOBUF']:
+    for proto in ProtoBuf.all:
+        # Use both the source and header as the target, and the .proto
+        # file as the source. When executing the protoc compiler, also
+        # specify the proto_path to avoid having the generated files
+        # include the path.
+        env.Command([proto.cc_file, proto.hh_file], proto.tnode,
+                    MakeAction('$PROTOC --cpp_out ${TARGET.dir} '
+                               '--proto_path ${SOURCE.dir} $SOURCE',
+                               Transform("PROTOC")))
+
+        # Add the C++ source file
+        Source(proto.cc_file, **proto.guards)
+elif ProtoBuf.all:
+    print 'Got protobuf to build, but lacks support!'
+    Exit(1)
 
-        class_path = obj.cxx_class.split('::')
-        classname = class_path[-1]
-        namespaces = class_path[:-1]
-        namespaces.reverse()
+#
+# Handle debug flags
+#
+def makeDebugFlagCC(target, source, env):
+    assert(len(target) == 1 and len(source) == 1)
 
-        code = ''
+    val = eval(source[0].get_contents())
+    name, compound, desc = val
+    compound = list(sorted(compound))
 
-        if namespaces:
-            code += '// avoid name conflicts\n'
-            sep_string = '_COLONS_'
-            flat_name = sep_string.join(class_path)
-            code += '%%rename(%s) %s;\n' % (flat_name, classname)
+    code = code_formatter()
 
-        code += '// stop swig from creating/wrapping default ctor/dtor\n'
-        code += '%%nodefault %s;\n' % classname
-        code += 'class %s ' % classname
-        if obj._base:
-            code += ': public %s' % obj._base.cxx_class
-        code += ' {};\n'
+    # file header
+    code('''
+/*
+ * DO NOT EDIT THIS FILE! Automatically generated
+ */
 
-        for ns in namespaces:
-            new_code = 'namespace %s {\n' % ns
-            new_code += code
-            new_code += '}\n'
-            code = new_code
+#include "base/debug.hh"
+''')
 
-        print >>out, code
+    for flag in compound:
+        code('#include "debug/$flag.hh"')
+    code()
+    code('namespace Debug {')
+    code()
 
-    print >>out, '%%include "src/sim/sim_object_params.hh"' % obj
-    for obj in ordered_objs:
-        print >>out, '%%include "params/%s.hh"' % obj
+    if not compound:
+        code('SimpleFlag $name("$name", "$desc");')
+    else:
+        code('CompoundFlag $name("$name", "$desc",')
+        code.indent()
+        last = len(compound) - 1
+        for i,flag in enumerate(compound):
+            if i != last:
+                code('$flag,')
+            else:
+                code('$flag);')
+        code.dedent()
 
-params_file = File('params/params.i')
-names = sort_list(sim_objects.keys())
-env.Command(params_file, [ Value(v) for v in names ], buildParams)
-env.Depends(params_file, params_hh_files + params_i_files + depends)
-SwigSource('m5.objects', params_file)
+    code()
+    code('} // namespace Debug')
 
-# Build all swig modules
-swig_modules = []
-cc_swig_sources = []
-for source,package in swig_sources:
-    filename = str(source)
-    assert filename.endswith('.i')
-
-    base = '.'.join(filename.split('.')[:-1])
-    module = basename(base)
-    cc_file = base + '_wrap.cc'
-    py_file = base + '.py'
-
-    env.Command([cc_file, py_file], source,
-                '$SWIG $SWIGFLAGS -outdir ${TARGETS[1].dir} '
-                '-o ${TARGETS[0]} $SOURCES')
-    env.Depends(py_file, source)
-    env.Depends(cc_file, source)
-
-    swig_modules.append(Value(module))
-    cc_swig_sources.append(File(cc_file))
-    PySource(package, py_file)
+    code.write(str(target[0]))
 
-# Generate the main swig init file
-def makeSwigInit(target, source, env):
-    f = file(str(target[0]), 'w')
-    print >>f, 'extern "C" {'
-    for module in source:
-        print >>f, '    void init_%s();' % module.get_contents()
-    print >>f, '}'
-    print >>f, 'void initSwig() {'
-    for module in source:
-        print >>f, '    init_%s();' % module.get_contents()
-    print >>f, '}'
-    f.close()
-
-env.Command('python/swig/init.cc', swig_modules, makeSwigInit)
-Source('python/swig/init.cc')
-
-# Generate traceflags.py
-def traceFlagsPy(target, source, env):
-    assert(len(target) == 1)
-
-    f = file(str(target[0]), 'w')
-
-    allFlags = []
-    for s in source:
-        val = eval(s.get_contents())
-        allFlags.append(val)
-
-    allFlags.sort()
-
-    print >>f, 'basic = ['
-    for flag, compound, desc in allFlags:
-        if not compound:
-            print >>f, "    '%s'," % flag
-    print >>f, "    ]"
-    print >>f
-
-    print >>f, 'compound = ['
-    print >>f, "    'All',"
-    for flag, compound, desc in allFlags:
-        if compound:
-            print >>f, "    '%s'," % flag
-    print >>f, "    ]"
-    print >>f
-
-    print >>f, "all = frozenset(basic + compound)"
-    print >>f
-
-    print >>f, 'compoundMap = {'
-    all = tuple([flag for flag,compound,desc in allFlags if not compound])
-    print >>f, "    'All' : %s," % (all, )
-    for flag, compound, desc in allFlags:
-        if compound:
-            print >>f, "    '%s' : %s," % (flag, compound)
-    print >>f, "    }"
-    print >>f
-
-    print >>f, 'descriptions = {'
-    print >>f, "    'All' : 'All flags',"
-    for flag, compound, desc in allFlags:
-        print >>f, "    '%s' : '%s'," % (flag, desc)
-    print >>f, "    }"
-
-    f.close()
-
-def traceFlagsCC(target, source, env):
-    assert(len(target) == 1)
-
-    f = file(str(target[0]), 'w')
-
-    allFlags = []
-    for s in source:
-        val = eval(s.get_contents())
-        allFlags.append(val)
+def makeDebugFlagHH(target, source, env):
+    assert(len(target) == 1 and len(source) == 1)
 
-    # file header
-    print >>f, '''
-/*
- * DO NOT EDIT THIS FILE! Automatically generated
- */
+    val = eval(source[0].get_contents())
+    name, compound, desc = val
 
-#include "base/traceflags.hh"
-
-using namespace Trace;
-
-const char *Trace::flagStrings[] =
-{'''
-
-    # The string array is used by SimpleEnumParam to map the strings
-    # provided by the user to enum values.
-    for flag, compound, desc in allFlags:
-        if not compound:
-            print >>f, '    "%s",' % flag
-
-    print >>f, '    "All",'
-    for flag, compound, desc in allFlags:
-        if compound:
-            print >>f, '    "%s",' % flag
-
-    print >>f, '};'
-    print >>f
-    print >>f, 'const int Trace::numFlagStrings = %d;' % (len(allFlags) + 1)
-    print >>f
-
-    #
-    # Now define the individual compound flag arrays.  There is an array
-    # for each compound flag listing the component base flags.
-    #
-    all = tuple([flag for flag,compound,desc in allFlags if not compound])
-    print >>f, 'static const Flags AllMap[] = {'
-    for flag, compound, desc in allFlags:
-        if not compound:
-            print >>f, "    %s," % flag
-    print >>f, '};'
-    print >>f
-
-    for flag, compound, desc in allFlags:
-        if not compound:
-            continue
-        print >>f, 'static const Flags %sMap[] = {' % flag
-        for flag in compound:
-            print >>f, "    %s," % flag
-        print >>f, "    (Flags)-1"
-        print >>f, '};'
-        print >>f
-
-    #
-    # Finally the compoundFlags[] array maps the compound flags
-    # to their individual arrays/
-    #
-    print >>f, 'const Flags *Trace::compoundFlags[] ='
-    print >>f, '{'
-    print >>f, '    AllMap,'
-    for flag, compound, desc in allFlags:
-        if compound:
-            print >>f, '    %sMap,' % flag
-    # file trailer
-    print >>f, '};'
-
-    f.close()
-
-def traceFlagsHH(target, source, env):
-    assert(len(target) == 1)
-
-    f = file(str(target[0]), 'w')
-
-    allFlags = []
-    for s in source:
-        val = eval(s.get_contents())
-        allFlags.append(val)
+    code = code_formatter()
 
     # file header boilerplate
-    print >>f, '''
+    code('''\
 /*
  * DO NOT EDIT THIS FILE!
  *
- * Automatically generated from traceflags.py
+ * Automatically generated by SCons
  */
 
-#ifndef __BASE_TRACE_FLAGS_HH__
-#define __BASE_TRACE_FLAGS_HH__
-
-namespace Trace {
-
-enum Flags {'''
-
-    # Generate the enum.  Base flags come first, then compound flags.
-    idx = 0
-    for flag, compound, desc in allFlags:
-        if not compound:
-            print >>f, '    %s = %d,' % (flag, idx)
-            idx += 1
-
-    numBaseFlags = idx
-    print >>f, '    NumFlags = %d,' % idx
+#ifndef __DEBUG_${name}_HH__
+#define __DEBUG_${name}_HH__
 
-    # put a comment in here to separate base from compound flags
-    print >>f, '''
-// The remaining enum values are *not* valid indices for Trace::flags.
-// They are "compound" flags, which correspond to sets of base
-// flags, and are used by changeFlag.'''
+namespace Debug {
+''')
 
-    print >>f, '    All = %d,' % idx
-    idx += 1
-    for flag, compound, desc in allFlags:
-        if compound:
-            print >>f, '    %s = %d,' % (flag, idx)
-            idx += 1
+    if compound:
+        code('class CompoundFlag;')
+    code('class SimpleFlag;')
 
-    numCompoundFlags = idx - numBaseFlags
-    print >>f, '    NumCompoundFlags = %d' % numCompoundFlags
-
-    # trailer boilerplate
-    print >>f, '''\
-}; // enum Flags
-
-// Array of strings for SimpleEnumParam
-extern const char *flagStrings[];
-extern const int numFlagStrings;
-
-// Array of arraay pointers: for each compound flag, gives the list of
-// base flags to set.  Inidividual flag arrays are terminated by -1.
-extern const Flags *compoundFlags[];
+    if compound:
+        code('extern CompoundFlag $name;')
+        for flag in compound:
+            code('extern SimpleFlag $flag;')
+    else:
+        code('extern SimpleFlag $name;')
 
-/* namespace Trace */ }
+    code('''
+}
 
-#endif // __BASE_TRACE_FLAGS_HH__
-'''
+#endif // __DEBUG_${name}_HH__
+''')
 
-    f.close()
+    code.write(str(target[0]))
 
-flags = [ Value(f) for f in trace_flags.values() ]
-env.Command('base/traceflags.py', flags, traceFlagsPy)
-PySource('m5', 'base/traceflags.py')
+for name,flag in sorted(debug_flags.iteritems()):
+    n, compound, desc = flag
+    assert n == name
 
-env.Command('base/traceflags.hh', flags, traceFlagsHH)
-env.Command('base/traceflags.cc', flags, traceFlagsCC)
-Source('base/traceflags.cc')
+    env.Command('debug/%s.hh' % name, Value(flag),
+                MakeAction(makeDebugFlagHH, Transform("TRACING", 0)))
+    env.Command('debug/%s.cc' % name, Value(flag),
+                MakeAction(makeDebugFlagCC, Transform("TRACING", 0)))
+    Source('debug/%s.cc' % name)
 
-# embed python files.  All .py files that have been indicated by a
+# Embed python files.  All .py files that have been indicated by a
 # PySource() call in a SConscript need to be embedded into the M5
 # library.  To do that, we compile the file to byte code, marshal the
-# byte code, compress it, and then generate an assembly file that
-# inserts the result into the data section with symbols indicating the
-# beginning, and end (and with the size at the end)
-py_sources_tnodes = {}
-for pysource in py_sources:
-    py_sources_tnodes[pysource.tnode] = pysource
-
-def objectifyPyFile(target, source, env):
+# byte code, compress it, and then generate a c++ file that
+# inserts the result into an array.
+def embedPyFile(target, source, env):
+    def c_str(string):
+        if string is None:
+            return "0"
+        return '"%s"' % string
+
     '''Action function to compile a .py into a code object, marshal
     it, compress it, and stick it into an asm file so the code appears
     as just bytes with a label in the data section'''
 
     src = file(str(source[0]), 'r').read()
-    dst = file(str(target[0]), 'w')
 
-    pysource = py_sources_tnodes[source[0]]
-    compiled = compile(src, pysource.debugname, 'exec')
+    pysource = PySource.tnodes[source[0]]
+    compiled = compile(src, pysource.abspath, 'exec')
     marshalled = marshal.dumps(compiled)
     compressed = zlib.compress(marshalled)
     data = compressed
+    sym = pysource.symname
 
-    # Some C/C++ compilers prepend an underscore to global symbol
-    # names, so if they're going to do that, we need to prepend that
-    # leading underscore to globals in the assembly file.
-    if env['LEADING_UNDERSCORE']:
-        sym = '_' + pysource.symname
-    else:
-        sym = pysource.symname
+    code = code_formatter()
+    code('''\
+#include "sim/init.hh"
 
+namespace {
+
+const uint8_t data_${sym}[] = {
+''')
+    code.indent()
     step = 16
-    print >>dst, ".data"
-    print >>dst, ".globl %s_beg" % sym
-    print >>dst, ".globl %s_end" % sym
-    print >>dst, "%s_beg:" % sym
     for i in xrange(0, len(data), step):
         x = array.array('B', data[i:i+step])
-        print >>dst, ".byte", ','.join([str(d) for d in x])
-    print >>dst, "%s_end:" % sym
-    print >>dst, ".long %d" % len(marshalled)
-
-for source in py_sources:
-    env.Command(source.assembly, source.tnode, objectifyPyFile)
-    Source(source.assembly)
-
-# Generate init_python.cc which creates a bunch of EmbeddedPyModule
-# structs that describe the embedded python code.  One such struct
-# contains information about the importer that python uses to get at
-# the embedded files, and then there's a list of all of the rest that
-# the importer uses to load the rest on demand.
-py_sources_symbols = {}
-for pysource in py_sources:
-    py_sources_symbols[pysource.symname] = pysource
-def pythonInit(target, source, env):
-    dst = file(str(target[0]), 'w')
-
-    def dump_mod(sym, endchar=','):
-        pysource = py_sources_symbols[sym]
-        print >>dst, '    { "%s",' % pysource.arcname
-        print >>dst, '      "%s",' % pysource.modpath
-        print >>dst, '       %s_beg, %s_end,' % (sym, sym)
-        print >>dst, '       %s_end - %s_beg,' % (sym, sym)
-        print >>dst, '       *(int *)%s_end }%s'  % (sym, endchar)
+        code(''.join('%d,' % d for d in x))
+    code.dedent()
     
-    print >>dst, '#include "sim/init.hh"'
+    code('''};
 
-    for sym in source:
-        sym = sym.get_contents()
-        print >>dst, "extern const char %s_beg[], %s_end[];" % (sym, sym)
+EmbeddedPython embedded_${sym}(
+    ${{c_str(pysource.arcname)}},
+    ${{c_str(pysource.abspath)}},
+    ${{c_str(pysource.modpath)}},
+    data_${sym},
+    ${{len(data)}},
+    ${{len(marshalled)}});
 
-    print >>dst, "const EmbeddedPyModule embeddedPyImporter = "
-    dump_mod("PyEMB_importer", endchar=';');
-    print >>dst
+} // anonymous namespace
+''')
+    code.write(str(target[0]))
 
-    print >>dst, "const EmbeddedPyModule embeddedPyModules[] = {"
-    for i,sym in enumerate(source):
-        sym = sym.get_contents()
-        if sym == "PyEMB_importer":
-            # Skip the importer since we've already exported it
-            continue
-        dump_mod(sym)
-    print >>dst, "    { 0, 0, 0, 0, 0, 0 }"
-    print >>dst, "};"
-
-symbols = [Value(s.symname) for s in py_sources]
-env.Command('sim/init_python.cc', symbols, pythonInit)
-Source('sim/init_python.cc')
+for source in PySource.all:
+    env.Command(source.cpp, source.tnode, 
+                MakeAction(embedPyFile, Transform("EMBED PY")))
+    Source(source.cpp)
 
 ########################################################################
 #
@@ -951,26 +874,7 @@ Source('sim/init_python.cc')
 # List of constructed environments to pass back to SConstruct
 envList = []
 
-# This function adds the specified sources to the given build
-# environment, and returns a list of all the corresponding SCons
-# Object nodes (including an extra one for date.cc).  We explicitly
-# add the Object nodes so we can set up special dependencies for
-# date.cc.
-def make_objs(sources, env, static):
-    if static:
-        XObject = env.StaticObject
-    else:
-        XObject = env.SharedObject
-
-    objs = [ XObject(s) for s in sources ]
-  
-    # make date.cc depend on all other objects so it always gets
-    # recompiled whenever anything else does
-    date_obj = XObject('base/date.cc')
-
-    env.Depends(date_obj, objs)
-    objs.append(date_obj)
-    return objs
+date_source = Source('base/date.cc', skip_lib=True)
 
 # Function to create a new build environment as clone of current
 # environment 'env' with modified object suffix and optional stripped
@@ -979,91 +883,216 @@ def make_objs(sources, env, static):
 def makeEnv(label, objsfx, strip = False, **kwargs):
     # SCons doesn't know to append a library suffix when there is a '.' in the
     # name.  Use '_' instead.
-    libname = 'm5_' + label
-    exename = 'm5.' + label
+    libname = 'gem5_' + label
+    exename = 'gem5.' + label
+    secondary_exename = 'm5.' + label
 
-    new_env = env.Copy(OBJSUFFIX=objsfx, SHOBJSUFFIX=objsfx + 's')
+    new_env = env.Clone(OBJSUFFIX=objsfx, SHOBJSUFFIX=objsfx + 's')
     new_env.Label = label
     new_env.Append(**kwargs)
 
-    swig_env = new_env.Copy()
+    swig_env = new_env.Clone()
+
+    # Both gcc and clang have issues with unused labels and values in
+    # the SWIG generated code
+    swig_env.Append(CCFLAGS=['-Wno-unused-label', '-Wno-unused-value'])
+
+    # Add additional warnings here that should not be applied to
+    # the SWIG generated code
+    new_env.Append(CXXFLAGS='-Wmissing-declarations')
+
     if env['GCC']:
-        swig_env.Append(CCFLAGS='-Wno-uninitialized')
-        swig_env.Append(CCFLAGS='-Wno-sign-compare')
-        swig_env.Append(CCFLAGS='-Wno-parentheses')
+        # Depending on the SWIG version, we also need to supress
+        # warnings about uninitialized variables and missing field
+        # initializers.
+        swig_env.Append(CCFLAGS=['-Wno-uninitialized',
+                                 '-Wno-missing-field-initializers'])
+
+        if compareVersions(env['GCC_VERSION'], '4.6') >= 0:
+            swig_env.Append(CCFLAGS='-Wno-unused-but-set-variable')
+
+        # If gcc supports it, also warn for deletion of derived
+        # classes with non-virtual desctructors. For gcc >= 4.7 we
+        # also have to disable warnings about the SWIG code having
+        # potentially uninitialized variables.
+        if compareVersions(env['GCC_VERSION'], '4.7') >= 0:
+            new_env.Append(CXXFLAGS='-Wdelete-non-virtual-dtor')
+            swig_env.Append(CCFLAGS='-Wno-maybe-uninitialized')
+    if env['CLANG']:
+        # Always enable the warning for deletion of derived classes
+        # with non-virtual destructors
+        new_env.Append(CXXFLAGS=['-Wdelete-non-virtual-dtor'])
+
+    werror_env = new_env.Clone()
+    werror_env.Append(CCFLAGS='-Werror')
+
+    def make_obj(source, static, extra_deps = None):
+        '''This function adds the specified source to the correct
+        build environment, and returns the corresponding SCons Object
+        nodes'''
+
+        if source.swig:
+            env = swig_env
+        elif source.Werror:
+            env = werror_env
+        else:
+            env = new_env
 
-    static_objs = make_objs(cc_lib_sources, new_env, static=True)
-    shared_objs = make_objs(cc_lib_sources, new_env, static=False)
-    static_objs += [ swig_env.StaticObject(s) for s in cc_swig_sources ]
-    shared_objs += [ swig_env.SharedObject(s) for s in cc_swig_sources ]
+        if static:
+            obj = env.StaticObject(source.tnode)
+        else:
+            obj = env.SharedObject(source.tnode)
+
+        if extra_deps:
+            env.Depends(obj, extra_deps)
+
+        return obj
+
+    static_objs = \
+        [ make_obj(s, True) for s in Source.get(main=False, skip_lib=False) ]
+    shared_objs = \
+        [ make_obj(s, False) for s in Source.get(main=False, skip_lib=False) ]
+
+    static_date = make_obj(date_source, static=True, extra_deps=static_objs)
+    static_objs.append(static_date)
+    
+    shared_date = make_obj(date_source, static=False, extra_deps=shared_objs)
+    shared_objs.append(shared_date)
 
     # First make a library of everything but main() so other programs can
     # link against m5.
     static_lib = new_env.StaticLibrary(libname, static_objs)
     shared_lib = new_env.SharedLibrary(libname, shared_objs)
 
-    for target, sources in unit_tests:
-        objs = [ new_env.StaticObject(s) for s in sources ]
-        new_env.Program("unittest/%s.%s" % (target, label), objs + static_lib)
-
     # Now link a stub with main() and the static library.
-    objects = [new_env.Object(s) for s in cc_bin_sources] + static_lib
+    main_objs = [ make_obj(s, True) for s in Source.get(main=True) ]
+
+    for test in UnitTest.all:
+        flags = { test.target : True }
+        test_sources = Source.get(**flags)
+        test_objs = [ make_obj(s, static=True) for s in test_sources ]
+        if test.main:
+            test_objs += main_objs
+        testname = "unittest/%s.%s" % (test.target, label)
+        new_env.Program(testname, test_objs + static_objs)
+
+    progname = exename
+    if strip:
+        progname += '.unstripped'
+
+    targets = new_env.Program(progname, main_objs + static_objs)
+
     if strip:
-        unstripped_exe = exename + '.unstripped'
-        new_env.Program(unstripped_exe, objects)
         if sys.platform == 'sunos5':
             cmd = 'cp $SOURCE $TARGET; strip $TARGET'
         else:
             cmd = 'strip $SOURCE -o $TARGET'
-        targets = new_env.Command(exename, unstripped_exe, cmd)
-    else:
-        targets = new_env.Program(exename, objects)
-            
+        targets = new_env.Command(exename, progname,
+                    MakeAction(cmd, Transform("STRIP")))
+
+    new_env.Command(secondary_exename, exename,
+            MakeAction('ln $SOURCE $TARGET', Transform("HARDLINK")))
+
     new_env.M5Binary = targets[0]
     envList.append(new_env)
 
-# Debug binary
-ccflags = {}
+# Start out with the compiler flags common to all compilers,
+# i.e. they all use -g for opt and -g -pg for prof
+ccflags = {'debug' : [], 'opt' : ['-g'], 'fast' : [], 'prof' : ['-g', '-pg'],
+           'perf' : ['-g']}
+
+# Start out with the linker flags common to all linkers, i.e. -pg for
+# prof, and -lprofiler for perf. The -lprofile flag is surrounded by
+# no-as-needed and as-needed as the binutils linker is too clever and
+# simply doesn't link to the library otherwise.
+ldflags = {'debug' : [], 'opt' : [], 'fast' : [], 'prof' : ['-pg'],
+           'perf' : ['-Wl,--no-as-needed', '-lprofiler', '-Wl,--as-needed']}
+
+# For Link Time Optimization, the optimisation flags used to compile
+# individual files are decoupled from those used at link time
+# (i.e. you can compile with -O3 and perform LTO with -O0), so we need
+# to also update the linker flags based on the target.
 if env['GCC']:
     if sys.platform == 'sunos5':
-        ccflags['debug'] = '-gstabs+'
+        ccflags['debug'] += ['-gstabs+']
     else:
-        ccflags['debug'] = '-ggdb3'
-    ccflags['opt'] = '-g -O3'
-    ccflags['fast'] = '-O3'
-    ccflags['prof'] = '-O3 -g -pg'
-elif env['SUNCC']:
-    ccflags['debug'] = '-g0'
-    ccflags['opt'] = '-g -O'
-    ccflags['fast'] = '-fast'
-    ccflags['prof'] = '-fast -g -pg'
-elif env['ICC']:
-    ccflags['debug'] = '-g -O0'
-    ccflags['opt'] = '-g -O'
-    ccflags['fast'] = '-fast'
-    ccflags['prof'] = '-fast -g -pg'
+        ccflags['debug'] += ['-ggdb3']
+    ldflags['debug'] += ['-O0']
+    # opt, fast, prof and perf all share the same cc flags, also add
+    # the optimization to the ldflags as LTO defers the optimization
+    # to link time
+    for target in ['opt', 'fast', 'prof', 'perf']:
+        ccflags[target] += ['-O3']
+        ldflags[target] += ['-O3']
+
+    ccflags['fast'] += env['LTO_CCFLAGS']
+    ldflags['fast'] += env['LTO_LDFLAGS']
+elif env['CLANG']:
+    ccflags['debug'] += ['-g', '-O0']
+    # opt, fast, prof and perf all share the same cc flags
+    for target in ['opt', 'fast', 'prof', 'perf']:
+        ccflags[target] += ['-O3']
 else:
     print 'Unknown compiler, please fix compiler options'
     Exit(1)
 
-makeEnv('debug', '.do',
-        CCFLAGS = Split(ccflags['debug']),
-        CPPDEFINES = ['DEBUG', 'TRACING_ON=1'])
+
+# To speed things up, we only instantiate the build environments we
+# need.  We try to identify the needed environment for each target; if
+# we can't, we fall back on instantiating all the environments just to
+# be safe.
+target_types = ['debug', 'opt', 'fast', 'prof', 'perf']
+obj2target = {'do': 'debug', 'o': 'opt', 'fo': 'fast', 'po': 'prof',
+              'gpo' : 'perf'}
+
+def identifyTarget(t):
+    ext = t.split('.')[-1]
+    if ext in target_types:
+        return ext
+    if obj2target.has_key(ext):
+        return obj2target[ext]
+    match = re.search(r'/tests/([^/]+)/', t)
+    if match and match.group(1) in target_types:
+        return match.group(1)
+    return 'all'
+
+needed_envs = [identifyTarget(target) for target in BUILD_TARGETS]
+if 'all' in needed_envs:
+    needed_envs += target_types
+
+# Debug binary
+if 'debug' in needed_envs:
+    makeEnv('debug', '.do',
+            CCFLAGS = Split(ccflags['debug']),
+            CPPDEFINES = ['DEBUG', 'TRACING_ON=1'],
+            LINKFLAGS = Split(ldflags['debug']))
 
 # Optimized binary
-makeEnv('opt', '.o',
-        CCFLAGS = Split(ccflags['opt']),
-        CPPDEFINES = ['TRACING_ON=1'])
+if 'opt' in needed_envs:
+    makeEnv('opt', '.o',
+            CCFLAGS = Split(ccflags['opt']),
+            CPPDEFINES = ['TRACING_ON=1'],
+            LINKFLAGS = Split(ldflags['opt']))
 
 # "Fast" binary
-makeEnv('fast', '.fo', strip = True,
-        CCFLAGS = Split(ccflags['fast']),
-        CPPDEFINES = ['NDEBUG', 'TRACING_ON=0'])
-
-# Profiled binary
-makeEnv('prof', '.po',
-        CCFLAGS = Split(ccflags['prof']),
-        CPPDEFINES = ['NDEBUG', 'TRACING_ON=0'],
-        LINKFLAGS = '-pg')
+if 'fast' in needed_envs:
+    makeEnv('fast', '.fo', strip = True,
+            CCFLAGS = Split(ccflags['fast']),
+            CPPDEFINES = ['NDEBUG', 'TRACING_ON=0'],
+            LINKFLAGS = Split(ldflags['fast']))
+
+# Profiled binary using gprof
+if 'prof' in needed_envs:
+    makeEnv('prof', '.po',
+            CCFLAGS = Split(ccflags['prof']),
+            CPPDEFINES = ['NDEBUG', 'TRACING_ON=0'],
+            LINKFLAGS = Split(ldflags['prof']))
+
+# Profiled binary using google-pprof
+if 'perf' in needed_envs:
+    makeEnv('perf', '.gpo',
+            CCFLAGS = Split(ccflags['perf']),
+            CPPDEFINES = ['NDEBUG', 'TRACING_ON=0'],
+            LINKFLAGS = Split(ldflags['perf']))
 
 Return('envList')