py10x-fin-base-cxx (cxxfin import)

Native extension for py10x-fin-base. Dist name is py10x-fin-base-cxx; the import module remains cxxfin. Install py10x-fin-base (not this package directly). Built with pybind11 and scikit-build-core.

Architecture

• cxxfin.cpp — pybind11 module source; PYBIND11_MODULE name is cxxfin
• generate_stubs.py — post-build stub generation; promotes py10x_kernel to RTLD_GLOBAL before importing cxxfin so that BTraitable typeinfo is visible (macOS flat namespace requirement)
• Headers from the py10x repo's cxx10x/ at the exact git commit matching the installed py10x_kernel binary (version string contains the hash), or the local tree when py10x-kernel is installed editable

Subclassing py10x_kernel types

py10x_kernel is built with CXX_VISIBILITY_PRESET default so its vtables and typeinfo are exported. On import it promotes itself to RTLD_GLOBAL via dladdr + dlopen(RTLD_NOW | RTLD_GLOBAL | RTLD_NOLOAD), making its symbols visible to subsequently loaded extension modules. py10x_kernel must be imported before cxxfin — this holds in normal usage since it is always loaded as part of the py10x-core import chain.

Incremental, automatic rebuild

cxxfin follows the active ./xx-build build mode, like py10x-kernel / py10x-infra. In dev (the default) and dev-release, it is installed editable with a persistent build dir under build/py10x-build/cxxfin/<Debug|Release>/ and is automatically rebuilt on import cxxfin whenever the sources changed. In ci-release (what CI uses) it is editable with no rebuild-on-import check. See dev_10x/README.md for the modes.

Clean rebuild

Needed when changing build structure, e.g. adding source files, editing CMakeLists.txt):

uv pip uninstall py10x-fin-base-cxx
rm -rf build/py10x-build/cxxfin
uv sync --reinstall-package py10x-fin-base-cxx

• uv pip uninstall py10x-fin-base-cxx — removes the editable finder from site-packages, which otherwise intercepts import cxxfin during stub generation and causes a circular rebuild failure
• rm -rf build/py10x-build/cxxfin — wipes the stale CMake cache
• the re-sync rebuilds and reinstalls it from scratch

Normal development (edit C++ source → run) does not require this; the editable rebuild fires automatically on import.

CLion

Open xx_fin/cxxfin/ as the CLion project; everything it needs is shared through git:

• CMakePresets.json: a Windows-only Debug preset, selecting CLion's Visual Studio toolchain at MSVC 14.44. Elsewhere it does not exist (a condition), and CLion uses its own default profile, also named Debug - nothing to set up. On Windows, once: on first open CLion creates that default Debug profile too (default toolchain, whose configure fails), which hides the preset of the same name. Under Settings > Build, Execution, Deployment > CMake, delete that profile, enable the Debug preset, then Tools > CMake > Reset Cache and Reload Project.
• CMakeLists.txt creates and syncs xx_fin/cxxfin/.venv on every CLion configure (needs uv on PATH): py10x-fin-base (editable) and its locked dependencies from py10x's root uv.lock plus the dev extra, but not py10x-fin-base-cxx, so CLion's own cxxfin build is the one its stub generation imports. py10x-kernel / py10x-infra are built there editable, sharing their build dir with the root .venv. Package builds (scikit-build-core) skip all of this.
• .idea/runConfigurations/: build cxxfin builds it, then prints the module CLion built, with that venv, on every OS: it runs .venv/Scripts/python, which CMakeLists.txt links to bin/python outside Windows, and finds the build through a .pth file it writes into the venv.

Build type

cxxfin builds Debug by default for development (cmake.build-type in its pyproject.toml). For a Release build, switch the build mode (all the C++ packages, still rebuild-on-import):

./xx-build set-mode dev-release   # ./xx-build set-mode dev switches back

The build type is baked into the editable install along with the build dir. Because each type has its own tree under build/py10x-build/cxxfin/<Debug|Release>/, switching does not rebuild from scratch.