systemc: Add m5.systemc and m5.tlm python modules.

These will be how systemc and tlm APIs which are not attached to
SimObjects will be exposed. This avoids having to artificially attach
them to wrapping SimObjects for instance, which is a bit awkward
and non-obvious.

The python code which attaches the systemc and tlm modules to the
m5 modules lives in src/python/m5/__init__.py, but the modules
themselves live in src/systemc/python to keep all the systemc code
grouped together. It might be a little confusing to have a small part
of the glue that adds those modules in a separate place (__init__.py),
but that is, as far as I can tell, unavoidable, and it's better in my
opinion to keep the systemc code grouped together than to put it
alongside the other python code and __init__.py.

Change-Id: Iecb218daec5e15772152b5ad22b51f43b86c3d4b
Reviewed-on: https://gem5-review.googlesource.com/c/16563
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
diff --git a/src/python/m5/__init__.py b/src/python/m5/__init__.py
index d97727c..8cad3b8 100644
--- a/src/python/m5/__init__.py
+++ b/src/python/m5/__init__.py
@@ -47,9 +47,13 @@
 if in_gem5:
     from . import SimObject
     from . import core
+    from . import defines
     from . import objects
     from . import params
     from . import stats
+    if defines.buildEnv['USE_SYSTEMC']:
+        from . import systemc
+        from . import tlm
     from . import util
 
     from .event import *
diff --git a/src/systemc/python/SConscript b/src/systemc/python/SConscript
new file mode 100644
index 0000000..1764672
--- /dev/null
+++ b/src/systemc/python/SConscript
@@ -0,0 +1,34 @@
+# Copyright 2019 Google, Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Gabe Black
+
+Import('*')
+
+if not env['USE_SYSTEMC'] or not env['USE_PYTHON']:
+    Return()
+
+PySource('m5', 'systemc.py')
+PySource('m5', 'tlm.py')
diff --git a/src/systemc/python/systemc.py b/src/systemc/python/systemc.py
new file mode 100644
index 0000000..08ea50d
--- /dev/null
+++ b/src/systemc/python/systemc.py
@@ -0,0 +1,43 @@
+# Copyright 2019 Google, Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Gabe Black
+
+import _m5.systemc
+
+from _m5.systemc import sc_main
+from _m5.systemc import sc_time
+from _m5.systemc import sc_main_result_code, sc_main_result_str
+
+class ScMainResult(object):
+    def __init__(self, code, message):
+        self.code = code
+        self.message = message
+
+def sc_main_result():
+    '''Retrieve and return the results of running sc_main'''
+    return ScMainResult(sc_main_result_code(), sc_main_result_str())
+
+__all__ = [ 'sc_main', 'sc_time', 'sc_main_result' ]
diff --git a/src/systemc/python/tlm.py b/src/systemc/python/tlm.py
new file mode 100644
index 0000000..e490843
--- /dev/null
+++ b/src/systemc/python/tlm.py
@@ -0,0 +1,35 @@
+# Copyright 2019 Google, Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Authors: Gabe Black
+
+import _m5.systemc
+
+from _m5.systemc import tlm_global_quantum
+
+def tlm_global_quantum_instance():
+    return tlm_global_quantum.instance()
+
+__all__ = [ 'tlm_global_quantum_instance' ]