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CShim Writer

The CShim writer (headerkit.writers.cshim) generates pure C-ABI wrapper functions (extern "C") around C++ classes, constructors, destructors, methods, and namespaced free functions using opaque pointer handles.

Features

  • Opaque Handles: Wraps C++ class instances as typedef void* ClassNameHandle;.
  • Constructors & Destructors: Emits ClassName_create(...) and ClassName_destroy(handle).
  • Methods: Emits ClassName_methodName(handle, ...) forwarding calls to the underlying C++ instance.
  • Operators: Maps C++ overloaded operators (e.g. operator[], operator+=, operator==) to named C shim functions (e.g. ClassName_subscript, ClassName_op_add_assign, ClassName_op_equal).
  • Namespaces: Flattens nested C++ namespaces into prefix conventions (ns1_ns2_func()).

Usage

headerkit mylib.hpp -w cshim -o cshim:mylib_cshim.cpp

from headerkit.backends.libclang import LibclangBackend
from headerkit.writers.cshim import CShimWriter, write_cshim

backend = LibclangBackend()
header = backend.parse(code, "mylib.hpp", extra_args=["-x", "c++"])

writer = CShimWriter(header_path="mylib.hpp")
shim_code = writer.write(header)

API Reference

CShimWriter 

CShimWriter(*, catch_exceptions=False)

Bases: BaseWriter

Writer that generates C-ABI wrapper shims around C++ headers.

Emits two parts (or combined header/source): - extern "C" C API declarations - C++ implementation wrapping member calls, constructors, and destructors.

write_cshim 

write_cshim(header, *, catch_exceptions=False)

Convenience function to generate C-ABI shims from a Header IR.