scons,sim: Eliminate the generated cxx_config/init.cc file.

This file populated the "cxx_config_directory" map from type names to
directory entry generating types. It used a comprehensive list of
includes of all SimObject headers, and a comprehensive list of the
generating types to fill everything in.

Instead, this change creates a new singleton helper class which, when
instantiated as a static member of a CxxConfigParams subclass, will
install a pointer to a CxxConfigDirectoryEntry to that map during global
object construction time.

Also, this change renames the map to cxxConfigDirectory which is in
compliance with the style guide, and puts it behind an accessor which
returns a static variable which is the actual map. This avoids any
problems that might come from global object construction order.

Change-Id: Iaa913fbe5af1b11d90ca618e29420eeb7cb0faed
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49455
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

build_tools/cxx_config_hh.py

@@ -85,6 +85,9 @@ class ${param_class} : public CxxConfigParams, public ${sim_object_name}Params
         }
     };
 
+    static inline AddToConfigDir dirEntry
+        {"${sim_object_name}", new DirectoryEntry};
+
   public:
     bool setSimObject(const std::string &name, SimObject *simObject);
 
@@ -104,13 +107,6 @@ class ${param_class} : public CxxConfigParams, public ${sim_object_name}Params
     bool setPortConnectionCount(const std::string &name, unsigned int count);
 
     SimObject *simObjectCreate();
-
-    static CxxConfigDirectoryEntry *
-    makeDirectoryEntry()
-    {
-        return new DirectoryEntry;
-    }
-
 };
 
 } // namespace gem5

build_tools/cxx_config_init_cc.py

@@ -1,77 +0,0 @@
-# Copyright 2004-2006 The Regents of The University of Michigan
-# Copyright 2010-20013 Advanced Micro Devices, Inc.
-# Copyright 2013 Mark D. Hill and David A. Wood
-# Copyright 2017-2020 ARM Limited
-# Copyright 2021 Google, Inc.
-#
-# The license below extends only to copyright in the software and shall
-# not be construed as granting a license to any other intellectual
-# property including but not limited to intellectual property relating
-# to a hardware implementation of the functionality of the software
-# licensed hereunder.  You may use the software subject to the license
-# terms below provided that you ensure that this notice is replicated
-# unmodified and in its entirety in all distributions of the software,
-# modified or unmodified, in source code or in binary form.
-#
-# 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 sys
-
-from code_formatter import code_formatter
-
-parser = argparse.ArgumentParser()
-parser.add_argument('cxx_config_init_cc',
-        help='cxx config init cc file to generate')
-parser.add_argument('sim_objects', help='all simobjects to include', nargs='*')
-
-args = parser.parse_args()
-
-code = code_formatter()
-
-for sim_object in args.sim_objects:
-    code('#include "cxx_config/${sim_object}.hh"')
-
-code('''
-namespace gem5
-{
-
-void
-cxxConfigInit()
-{
-''')
-
-code.indent()
-for sim_object in args.sim_objects:
-    code('cxx_config_directory["${sim_object}"] = '
-         '${sim_object}CxxConfigParams::makeDirectoryEntry();')
-code.dedent()
-
-code('''
-}
-
-} // namespace gem5
-''')
-
-code.write(args.cxx_config_init_cc)

src/SConscript

@@ -133,10 +133,6 @@ class SimObject(PySource):
     '''Add a SimObject python file as a python source object and add
     it to a list of sim object modules'''
 
-    fixed = False
-
-    sim_objects = []
-
     def __init__(self, source, *, sim_objects=None, enums=None,
             tags=None, add_tags=None):
         '''Specify the source file and any tags (automatically in
@@ -150,10 +146,6 @@ class SimObject(PySource):
             enums = []
 
         super().__init__('m5.objects', source, tags, add_tags)
-        if self.fixed:
-            error("Too late to call SimObject now.")
-
-        SimObject.sim_objects.extend(sim_objects)
 
         build_dir = Dir(env['BUILDDIR'])
         module = self.modpath
@@ -587,13 +579,6 @@ def makeTheGPUISA(source, target, env):
 env.Command('config/the_gpu_isa.hh', [],
             MakeAction(makeTheGPUISA, 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
-
 
 ########################################################################
 #
@@ -631,25 +616,6 @@ m5_module_source = \
 m5_module_static = list(map(lambda s: s.static(gem5py_env), m5_module_source))
 gem5py_env.Program(gem5py_m5, [ 'python/gem5py.cc' ] + m5_module_static)
 
-########################################################################
-#
-# Create the CXX config init.cc.
-#
-
-all_sim_objects = sorted(SimObject.sim_objects)
-sim_object_args = list(f'"{sim_object}"' for sim_object in all_sim_objects)
-cc_file = File('cxx_config/init.cc')
-gem5py_env.Command([ "${CXXCONFIGINIT_CC}" ],
-        [ "${GEM5PY}", "${CXXCONFIGINITCC_PY}" ],
-        MakeAction('"${GEM5PY}" "${CXXCONFIGINITCC_PY}" "${TARGET}" '
-                '${SIM_OBJECTS}',
-            Transform("CXXCINIT", 0)),
-        CXXCONFIGINITCC_PY=build_tools.File('cxx_config_init_cc.py'),
-        SIM_OBJECTS=' '.join(sim_object_args),
-        CXXCONFIGINIT_CC=cc_file)
-if GetOption('with_cxx_config'):
-    Source(cc_file)
-
 
 # version tags
 tags = \

src/sim/cxx_config.cc

@@ -43,6 +43,11 @@ namespace gem5
 const std::string CxxConfigParams::invalidName = "<invalid>";
 
 /** Directory of all SimObject classes config details */
-std::map<std::string, CxxConfigDirectoryEntry *> cxx_config_directory;
+std::map<std::string, CxxConfigDirectoryEntry *> &
+cxxConfigDirectory()
+{
+    static std::map<std::string, CxxConfigDirectoryEntry *> dir;
+    return dir;
+}
 
 } // namespace gem5

src/sim/cxx_config.hh

@@ -119,6 +119,9 @@ class CxxConfigDirectoryEntry
     virtual ~CxxConfigDirectoryEntry() { }
 };
 
+/** Directory of all SimObject classes config details */
+std::map<std::string, CxxConfigDirectoryEntry *> &cxxConfigDirectory();
+
 /** Base for peer classes of SimObjectParams derived classes with parameter
  *  modifying member functions. C++ configuration will offer objects of
  *  these classes to SimObjects as params rather than SimObjectParams
@@ -128,6 +131,18 @@ class CxxConfigParams
   private:
     static const std::string invalidName;
 
+  protected:
+    struct AddToConfigDir
+    {
+        AddToConfigDir(const std::string &name, CxxConfigDirectoryEntry *entry)
+        {
+            auto it_success = cxxConfigDirectory().insert({name, entry});
+            panic_if(!it_success.second,
+                    "Failed to insert config directory entry %s (duplicate?).",
+                    name);
+        }
+    };
+
   public:
     /** Flags passable to setParam... to smooth over any parsing difference
      *  between different config files */
@@ -229,14 +244,6 @@ class CxxConfigFileBase
     virtual CxxConfigParams::Flags getFlags() const { return 0; }
 };
 
-/** Directory of all SimObject classes config details */
-extern std::map<std::string, CxxConfigDirectoryEntry *>
-    cxx_config_directory;
-
-/** Initialise cxx_config_directory.  This is defined in the
- *  auto-generated .../cxx_config/init.cc */
-void cxxConfigInit();
-
 } // namespace gem5
 
 #endif // __SIM_CXX_CONFIG_HH__

src/sim/cxx_manager.cc

@@ -65,14 +65,14 @@ CxxConfigManager::findObjectType(const std::string &object_name,
     if (!configFile.getParam(object_name, "type", object_type))
         throw Exception(object_name, "Sim object has no 'type' field");
 
-    if (cxx_config_directory.find(object_type) ==
+    if (cxxConfigDirectory().find(object_type) ==
-        cxx_config_directory.end())
+        cxxConfigDirectory().end())
     {
         throw Exception(object_name, csprintf(
             "No sim object type %s is available", object_type));
     }
 
-    const CxxConfigDirectoryEntry *entry = cxx_config_directory[object_type];
+    const CxxConfigDirectoryEntry *entry = cxxConfigDirectory()[object_type];
 
     return *entry;
 }