sim,misc: Move protobuf housekeeping out of gem5Main.

Put that code into a singleton class in src/proto, so that it gets
called during initialization and teardown of gem5 without cluttering up
gem5Main. This also removes the need to use #ifdefs to guard for
actualling having protobuf support.

Change-Id: I93b5d994eee478a9c159a3f3d02b3e996af02a3e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49416
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/proto/SConscript

@@ -42,6 +42,7 @@ if env['HAVE_PROTOBUF']:
     ProtoBuf('inst_dep_record.proto')
     ProtoBuf('packet.proto')
     ProtoBuf('inst.proto')
+    Source('protobuf.cc')
     Source('protoio.cc')
 
     # protoc relies on the fact that undefined preprocessor symbols are

src/proto/protobuf.cc

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2012, 2017 ARM Limited
+ * All rights reserved
+ *
+ * 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.
+ *
+ * Copyright (c) 2000-2005 The Regents of The University of Michigan
+ * Copyright (c) 2008 The Hewlett-Packard Development Company
+ * All rights reserved.
+ *
+ * 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.
+ */
+
+#include <google/protobuf/stubs/common.h>
+
+namespace gem5
+{
+
+namespace
+{
+
+struct ProtobufSingleton
+{
+    ProtobufSingleton()
+    {
+        // Verify that the version of the protobuf library that we linked
+        // against is compatible with the version of the headers we
+        // compiled against.
+        GOOGLE_PROTOBUF_VERIFY_VERSION;
+    }
+
+    ~ProtobufSingleton()
+    {
+        google::protobuf::ShutdownProtobufLibrary();
+    }
+} protobufSingleton;
+
+} // anonymous namespace
+
+} // namespace gem5

src/sim/init.cc

@@ -53,14 +53,8 @@
 #include "base/cprintf.hh"
 #include "base/logging.hh"
 #include "base/types.hh"
-#include "config/have_protobuf.hh"
 #include "python/pybind11/pybind.hh"
 
-#if HAVE_PROTOBUF
-#include <google/protobuf/stubs/common.h>
-
-#endif
-
 namespace py = pybind11;
 
 namespace gem5
@@ -204,14 +198,6 @@ PYBIND11_EMBEDDED_MODULE(_m5, _m5)
 int
 gem5Main(int argc, char **argv)
 {
-#if HAVE_PROTOBUF
-    // Verify that the version of the protobuf library that we linked
-    // against is compatible with the version of the headers we
-    // compiled against.
-    GOOGLE_PROTOBUF_VERIFY_VERSION;
-#endif
-
-
     // Embedded python doesn't set up sys.argv, so we'll do that ourselves.
     py::list py_argv;
     auto sys = py::module::import("sys");
@@ -239,10 +225,6 @@ gem5Main(int argc, char **argv)
         return 1;
     }
 
-#if HAVE_PROTOBUF
-    google::protobuf::ShutdownProtobufLibrary();
-#endif
-
     return 0;
 }