Add the ability to build libgem5 without embedded Python or the
ability to configure with Python.
This is a prelude to a patch to allow config.ini files to be loaded
into libgem5 using only C++ which would make embedding gem5 within
other simulation systems easier.
This adds a few registration interfaces to things which cross
between Python and C++. Namely: stats dumping and SimObject resolving
This patch addresses a number of minor issues that cause problems when
compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it
avoids using the deprecated ext/hash_map and instead uses
unordered_map (and similarly so for the hash_set). To make use of the
new STL containers, g++ and clang has to be invoked with "-std=c++0x",
and this is now added for all gcc versions >= 4.6, and for clang >=
3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1
unordered_map to avoid the deprecation warning.
The addition of c++0x in turn causes a few problems, as the
compiler is more stringent and adds a number of new warnings. Below,
the most important issues are enumerated:
1) the use of namespaces is more strict, e.g. for isnan, and all
headers opening the entire namespace std are now fixed.
2) another other issue caused by the more stringent compiler is the
narrowing of the embedded python, which used to be a char array,
and is now unsigned char since there were values larger than 128.
3) a particularly odd issue that arose with the new c++0x behaviour is
found in range.hh, where the operator< causes gcc to complain about
the template type parsing (the "<" is interpreted as the beginning
of a template argument), and the problem seems to be related to the
begin/end members introduced for the range-type iteration, which is
a new feature in c++11.
As a minor update, this patch also fixes the build flags for the clang
debug target that used to be shared with gcc and incorrectly use
"-ggdb".
Instead of putting all object files into m5/object/__init__.py, interrogate
the importer to find out what should be imported.
Instead of creating a single file that lists all of the embedded python
modules, use static object construction to put those objects onto a list.
Do something similar for embedded swig (C++) code.
If the user sets the environment variable M5_OVERRIDE_PY_SOURCE to
True, then imports that would normally find python code compiled into
the executable will instead first check in the absolute location where
the code was found during the build of the executable. This only
works for files in the src (or extras) directories, not automatically
generated files.
This is a developer feature!
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.
