scons: Also build param struct .cc files using a helper script.

There was a comment in the SConscript talking about building a single
.cc file for all the param structs, but that's not what the code was
actually doing. This change drops that misleading comment.

Change-Id: I3a5e4424e1021d6dfbdeafcef7709dae988747a4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49425
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

build_tools/sim_object_param_struct_cc.py

@@ -0,0 +1,62 @@
+# Copyright 2021 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.
+
+import argparse
+import importlib
+import os.path
+import sys
+
+import importer
+
+from code_formatter import code_formatter
+
+parser = argparse.ArgumentParser()
+parser.add_argument('modpath', help='module the simobject belongs to')
+parser.add_argument('param_cc', help='parameter cc file to generate')
+parser.add_argument('use_python',
+        help='whether python is enabled in gem5 (True or False)')
+
+args = parser.parse_args()
+
+use_python = args.use_python.lower()
+if use_python == 'true':
+    use_python = True
+elif use_python == 'false':
+    use_python = False
+else:
+    print(f'Unrecognized "use_python" value {use_python}', file=sys.stderr)
+    sys.exit(1)
+
+basename = os.path.basename(args.param_cc)
+no_ext = os.path.splitext(basename)[0]
+sim_object_name = '_'.join(no_ext.split('_')[1:])
+
+importer.install()
+module = importlib.import_module(args.modpath)
+sim_object = getattr(module, sim_object_name)
+
+code = code_formatter()
+sim_object.params_create_decl(code, use_python)
+code.write(args.param_cc)