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 fetched from cxx10x at the exact git commit matching the installed py10x_kernel binary (version string contains the hash)

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 is automatically rebuilt on import cxxfin whenever the sources changed.

Clean rebuild

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

uv pip uninstall py10x-fin-base-cxx
rm -rf .venv/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 .venv/py10x-build/cxxfin — wipes the stale CMake cache
• uv sync --reinstall-package py10x-fin-base-cxx — rebuilds and reinstalls from scratch

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

Debug build

cxxfin builds Release by default. For Debug build, set the build type via scikit-build-core's env override and re-run uv sync, for example:

SKBUILD_CMAKE_BUILD_TYPE=Debug uv sync --reinstall-package py10x-fin-base-cxx

The build type is fixed at sync time (baked into the editable install along with the build-dir), so switching is just another sync — SKBUILD_CMAKE_BUILD_TYPE=Debug uv sync --reinstall-package py10x-fin-base-cxx for Debug, plain uv sync --reinstall-package py10x-fin-base-cxx for Release. Because each type has its own tree under .venv/py10x-build/cxxfin/<Debug|Release>/, switching does not rebuild from scratch.