python

CPython demo

Builds the CPython 3.14.6 interpreter with badc and runs a slice of the standard library test suite. The interpreter exercises the bytecode evaluator, the object and memory model, Unicode, and the parser.

Layout

• setup.py -- fetches the pinned Python-3.14.6.tgz and the vendored frozen-module headers from the badc vendor-deps mirror and extracts them under .cache/Python-3.14.6. No make.
• build.py -- the build command for every target (macOS, Linux x64/arm64, Windows x64/arm64): compiles CPython's all-builtin link set with badc and runs the tier-1 test slice, with no make. POSIX targets use a committed per-target manifest.json + config.c + pyconfig.h; Windows targets parse the link set from PCbuild/pythoncore.vcxproj and wire the PC/config.c inittab.
• smoke.py -- the reference build: ./configure --without-mimalloc + make with the host compiler, producing a reference python for bench.py.
• bench.py + benchmarks/ -- runs the dependency-free pure-Python benchmarks on the badc-built interpreter and the smoke.py reference, asserts per-benchmark output parity (a differential correctness check over a workload broader than the test slice), and reports timings relative to the reference.

smoke.py configures --without-mimalloc --without-remote-debug; its docstring carries the first error each knob produces today. In short: mimalloc's per-thread heap table is a thread-local pointer initialized with the address of a global, which badc rejects, and the remote-debugging code needs process_vm_readv on Linux and libproc.h on macOS. --with-ensurepip has no effect on what badc compiles.

CI builds and tests every target with build.py -- a matrix over macOS, Linux x64/arm64, and Windows x64/arm64; each lane builds and runs natively. smoke.py and bench.py cover the differential benchmark, which still needs a make-built reference.

Running

python3 demos/python/setup.py                                # once, to fetch the source
python3 demos/python/build.py --target=macos-aarch64 --test  # build + run the test slice
python3 demos/python/build.py --target=windows-x64 --link    # build + link only
python3 demos/python/bench.py                                # parity + timings vs the reference

cargo build --release --features full must have produced target/release/badc first. bench.py reuses the reference interpreter built by smoke.py under .cache/.

Capturing the target inputs

targets/<target>/{pyconfig.h,config.c,manifest.json} are what configure and make derive on a host of the target's OS and architecture, from an all-builtin build of the release tarball that leaves out every module linking a library beyond the C library and the OS (on macOS _uuid comes off the list: libSystem provides it):

tar -xzf Python-<version>.tgz && cd Python-<version>
printf '%s\n' '*disabled*' _bz2 _lzma _zstd zlib _dbm _gdbm readline _ctypes \
    _curses _curses_panel _sqlite3 _ssl _hashlib _uuid _tkinter > Modules/Setup.local
./configure --without-mimalloc --without-remote-debug --with-ensurepip=no \
    --disable-test-modules --without-system-libmpdec --without-system-expat \
    MODULE_BUILDTYPE=static
make -j8 > ../trace.txt 2> ../make-stderr.txt
grep -E '^(gcc|cc|clang) .* -o python(\.exe)?( |$)' ../trace.txt > ../pylink.txt
python3 <repo>/demos/python/gen_manifest.py ../trace.txt ../pylink.txt ../manifest.json

pyconfig.h and Modules/config.c are then copied as they are. The trace takes stdout alone: a compiler warning interleaved into a parallel compile line drops that unit from the manifest. A bump keeps the host-dependent answers of the previous capture, so pyconfig.h changes only where upstream did: diff3 -m <committed> <old version on this host> <new version on this host>. For 3.14.6 the recipe gives the committed manifest.json (as a set of units with their defines and includes) and config.c on the Linux x86_64, Linux aarch64 and macOS arm64 hosts, except that the macOS config.c lists binascii last; pyconfig.h differs only where the hosts changed since: HAVE_UUID_H and HAVE_UUID_GENERATE_TIME_SAFE (libuuid-devel installed) on Linux, HAVE_DUP3 and HAVE_PIPE2 (the macOS 27 SDK) on macOS.

The frozen-module asset is Python/frozen_modules/ of any such build -- the headers make generates plus the tarball's README.txt -- packed with COPYFILE_DISABLE=1 tar --no-xattrs -czf python-frozen.tar.gz Python/frozen_modules and named python-frozen-<version>-<sha8>.tar.gz after its own sha256. The headers are marshalled bytecode, the same on every host: the 3.14.6 asset's 25 files equal those of a Linux x86_64 build.