libm5: Create a libm5 static library for embedding m5.

This should allow m5 to be more easily embedded into other simulators.
The m5 binary adds a simple main function which then calls into the m5
libarary to start the simulation. In order to make this work
correctly, it was necessary embed python code directly into the
library instead of the zipfile hack.  This is because you can't just
append the zipfile to the end of a library the way you can a binary.
As a result, Python files that are part of the m5 simulator are now
compile, marshalled, compressed, and then inserted into the library's
data section with a certain symbol name.  Additionally, a new Importer
was needed to allow python to get at the embedded python code.

Small additional changes include:
- Get rid of the PYTHONHOME stuff since I don't think anyone ever used
it, and it just confuses things.  Easy enough to add back if I'm wrong.
- Create a few new functions that are key to initializing and running
the simulator: initSignals, initM5Python, m5Main.

The original code for creating libm5 was inspired by a patch Michael
Adler, though the code here was done by me.

4 files changed, 274 insertions, 109 deletions

diff --git a/src/sim/SConscript b/src/sim/SConscript
index c9e4415f5..3e6adb85a 100644
--- a/src/sim/SConscript
+++ b/src/sim/SConscript
@@ -40,7 +40,8 @@ Source('core.cc')
 Source('debug.cc')
 Source('eventq.cc')
 Source('faults.cc')
-Source('main.cc')
+Source('init.cc')
+BinSource('main.cc')
 Source('root.cc')
 Source('serialize.cc')
 Source('sim_events.cc')
diff --git a/src/sim/init.cc b/src/sim/init.cc
new file mode 100644
index 000000000..804389dae
--- /dev/null
+++ b/src/sim/init.cc
@@ -0,0 +1,202 @@
+/*
+ * 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.
+ *
+ * Authors: Nathan Binkert
+ */
+
+#include <Python.h>
+#include <marshal.h>
+#include <signal.h>
+
+#include <iostream>
+#include <string>
+#include <zlib.h>
+
+#include "base/cprintf.hh"
+#include "base/misc.hh"
+#include "sim/async.hh"
+#include "sim/core.hh"
+#include "sim/host.hh"
+#include "sim/init.hh"
+
+using namespace std;
+
+/// Stats signal handler.
+void
+dumpStatsHandler(int sigtype)
+{
+    async_event = true;
+    async_statdump = true;
+}
+
+void
+dumprstStatsHandler(int sigtype)
+{
+    async_event = true;
+    async_statdump = true;
+    async_statreset = true;
+}
+
+/// Exit signal handler.
+void
+exitNowHandler(int sigtype)
+{
+    async_event = true;
+    async_exit = true;
+}
+
+/// Abort signal handler.
+void
+abortHandler(int sigtype)
+{
+    ccprintf(cerr, "Program aborted at cycle %d\n", curTick);
+}
+
+/*
+ * M5 can do several special things when various signals are sent.
+ * None are mandatory.
+ */
+void
+initSignals()
+{
+    // Floating point exceptions may happen on misspeculated paths, so
+    // ignore them
+    signal(SIGFPE, SIG_IGN);
+
+    // We use SIGTRAP sometimes for debugging
+    signal(SIGTRAP, SIG_IGN);
+
+    // Dump intermediate stats
+    signal(SIGUSR1, dumpStatsHandler);
+
+    // Dump intermediate stats and reset them
+    signal(SIGUSR2, dumprstStatsHandler);
+
+    // Exit cleanly on Interrupt (Ctrl-C)
+    signal(SIGINT, exitNowHandler);
+
+    // Print out cycle number on abort
+    signal(SIGABRT, abortHandler);
+}
+
+/*
+ * Uncompress and unmarshal the code object stored in the
+ * EmbeddedPyModule
+ */
+PyObject *
+getCode(const EmbeddedPyModule *pymod)
+{
+    assert(pymod->zlen == pymod->code_end - pymod->code);
+    Bytef *marshalled = new Bytef[pymod->mlen];
+    uLongf unzlen = pymod->mlen;
+    int ret = uncompress(marshalled, &unzlen, (const Bytef *)pymod->code,
+        pymod->zlen);
+    if (ret != Z_OK)
+        panic("Could not uncompress code: %s\n", zError(ret));
+    assert(unzlen == pymod->mlen);
+
+    return PyMarshal_ReadObjectFromString((char *)marshalled, pymod->mlen);
+}
+
+// The python library is totally messed up with respect to constness,
+// so make a simple macro to make life a little easier
+#define PyCC(x) (const_cast<char *>(x))
+
+/*
+ * Load and initialize all of the python parts of M5, including Swig
+ * and the embedded module importer.
+ */
+int
+initM5Python()
+{
+    extern void initSwig();
+
+    // initialize SWIG modules.  initSwig() is autogenerated and calls
+    // all of the individual swig initialization functions.
+    initSwig();
+
+    // Load the importer module
+    PyObject *code = getCode(&embeddedPyImporter);
+    PyObject *module = PyImport_ExecCodeModule(PyCC("importer"), code);
+    if (!module) {
+        PyErr_Print();
+        return 1;
+    }
+
+    // Load the rest of the embedded python files into the embedded
+    // python importer
+    const EmbeddedPyModule *pymod = &embeddedPyModules[0];
+    while (pymod->filename) {
+        PyObject *code = getCode(pymod);
+        PyObject *result = PyObject_CallMethod(module, PyCC("add_module"),
+            PyCC("ssO"), pymod->filename, pymod->modpath, code);
+        if (!result) {
+            PyErr_Print();
+            return 1;
+        }
+        Py_DECREF(result);
+        ++pymod;
+    }
+
+    return 0;
+}
+
+/*
+ * Start up the M5 simulator.  This mostly vectors into the python
+ * main function.
+ */
+int
+m5Main(int argc, char **argv)
+{
+    PySys_SetArgv(argc, argv);
+
+    // We have to set things up in the special __main__ module
+    PyObject *module = PyImport_AddModule(PyCC("__main__"));
+    if (module == NULL)
+        panic("Could not import __main__");
+    PyObject *dict = PyModule_GetDict(module);
+
+    // import the main m5 module
+    PyObject *result;
+    result = PyRun_String("import m5", Py_file_input, dict, dict);
+    if (!result) {
+        PyErr_Print();
+        return 1;
+    }
+    Py_DECREF(result);
+
+    // Start m5
+    result = PyRun_String("m5.main()", Py_file_input, dict, dict);
+    if (!result) {
+        PyErr_Print();
+        return 1;
+    }
+    Py_DECREF(result);
+
+    return 0;
+}
diff --git a/src/sim/init.hh b/src/sim/init.hh
new file mode 100644
index 000000000..b0f29bf30
--- /dev/null
+++ b/src/sim/init.hh
@@ -0,0 +1,54 @@
+/*
+ * 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.
+ *
+ * Authors: Nathan Binkert
+ */
+
+#ifndef __SIM_INIT_HH__
+#define __SIM_INIT_HH__
+
+/*
+ * Data structure describing an embedded python file.
+ */
+struct EmbeddedPyModule
+{
+    const char *filename;
+    const char *modpath;
+    const char *code;
+    const char *code_end;
+    int zlen;
+    int mlen;
+};
+
+extern const EmbeddedPyModule embeddedPyImporter;
+extern const EmbeddedPyModule embeddedPyModules[];
+
+void initSignals();
+int initM5Python();
+int m5Main(int argc, char **argv);
+
+#endif // __SIM_INIT_HH__
diff --git a/src/sim/main.cc b/src/sim/main.cc
index baca556a0..d674e0cff 100644
--- a/src/sim/main.cc
+++ b/src/sim/main.cc
@@ -1,5 +1,5 @@
 /*
- * 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
@@ -29,125 +29,33 @@
  */
 
 #include <Python.h>
-#include <signal.h>
 
-#include <iostream>
-#include <string>
-
-#include "base/cprintf.hh"
-#include "base/misc.hh"
-#include "config/pythonhome.hh"
-#include "python/swig/init.hh"
-#include "sim/async.hh"
-#include "sim/host.hh"
-#include "sim/core.hh"
-
-using namespace std;
-
-/// Stats signal handler.
-void
-dumpStatsHandler(int sigtype)
-{
-    async_event = true;
-    async_statdump = true;
-}
-
-void
-dumprstStatsHandler(int sigtype)
-{
-    async_event = true;
-    async_statdump = true;
-    async_statreset = true;
-}
-
-/// Exit signal handler.
-void
-exitNowHandler(int sigtype)
-{
-    async_event = true;
-    async_exit = true;
-}
-
-/// Abort signal handler.
-void
-abortHandler(int sigtype)
-{
-    ccprintf(cerr, "Program aborted at cycle %d\n", curTick);
-}
-
-int
-python_main()
-{
-    PyObject *module;
-    PyObject *dict;
-    PyObject *result;
-
-    module = PyImport_AddModule(const_cast<char*>("__main__"));
-    if (module == NULL)
-        fatal("Could not import __main__");
-
-    dict = PyModule_GetDict(module);
-
-    result = PyRun_String("import m5.main", Py_file_input, dict, dict);
-    if (!result) {
-        PyErr_Print();
-        return 1;
-    }
-    Py_DECREF(result);
-
-    result = PyRun_String("m5.main.main()", Py_file_input, dict, dict);
-    if (!result) {
-        PyErr_Print();
-        return 1;
-    }
-    Py_DECREF(result);
-
-    if (Py_FlushLine())
-        PyErr_Clear();
-
-    return 0;
-}
+#include "sim/init.hh"
 
+// main() is now pretty stripped down and just sets up python and then
+// calls initM5Python which loads the various embedded python modules
+// into the python environment and then starts things running by
+// calling m5Main.
 int
 main(int argc, char **argv)
 {
-    signal(SIGFPE, SIG_IGN);		// may occur on misspeculated paths
-    signal(SIGTRAP, SIG_IGN);
-    signal(SIGUSR1, dumpStatsHandler);		// dump intermediate stats
-    signal(SIGUSR2, dumprstStatsHandler);	// dump and reset stats
-    signal(SIGINT, exitNowHandler);		// dump final stats and exit
-    signal(SIGABRT, abortHandler);
-
-    Py_SetProgramName(argv[0]);
-
-    // default path to m5 python code is the currently executing
-    // file... Python ZipImporter will find embedded zip archive.
-    // The M5_ARCHIVE environment variable can be used to override this.
-    char *m5_archive = getenv("M5_ARCHIVE");
-    string pythonpath = m5_archive ? m5_archive : argv[0];
+    int ret;
 
-    char *oldpath = getenv("PYTHONPATH");
-    if (oldpath != NULL) {
-        pythonpath += ":";
-        pythonpath += oldpath;
-    }
-
-    if (setenv("PYTHONPATH", pythonpath.c_str(), true) == -1)
-        fatal("setenv: %s\n", strerror(errno));
+    // Initialize m5 special signal handling.
+    initSignals();
 
-    const char *python_home = getenv("PYTHONHOME");
-    if (!python_home)
-        python_home = PYTHONHOME;
-    Py_SetPythonHome(const_cast<char*>(python_home));
+    Py_SetProgramName(argv[0]);
 
     // initialize embedded Python interpreter
     Py_Initialize();
-    PySys_SetArgv(argc, argv);
 
-    // initialize SWIG modules
-    init_swig();
+    // Initialize the embedded m5 python library
+    ret = initM5Python();
 
-    int ret = python_main();
+    if (ret == 0) {
+        // start m5
+        ret = m5Main(argc, argv);
+    }
 
     // clean up Python intepreter.
     Py_Finalize();