ctypes

The Ctypes target emits a pure-Python API using the builtin Python/ctypes module.

What is produced:

• sugar for Python/ctypes (ctypes_sugar.py)

  • This is an expansion of the Python/ctypes module

• C API Wrapper ({meta.prefix}.py)

  • Python module mapping the Interface Definition to yace.target.ctypes

  • Constants become global variables in the {prefix} module, such as {prefix}.MIN_X.

  • EnumTypes mapped to yace.targets.ctypes.ctypes_sugar.Enum

  • Derived Types mapped to yace.targets.ctypes.ctypes_sugar.Structure

  • Derived Types mapped to yace.targets.ctypes.ctypes_sugar.Union

• Test ({meta.prefix}_check.py)

  • Imports and does basic library/loader verification of the C API Wrapper

Thus, the above files are what you should expect to see in the output-directory

System-Tools

The target uses the following system-tools to format the emitted code and verify it:

• yace.tools.Black

• yace.tools.Isort

• yace.tools.Python3

Implementation

What to do about “static” and “const”? The filter_typedecl.template currently ignores them, except for the special-case “c_char_p”.

class yace.targets.ctypes.target.Ctypes(output)

Several helper functions

NAME = 'ctypes'

check()

Build generated sources and run the generated test-program

emit(model)

Emit code

format()

Run ‘black’ and ‘isort’ on self.sources

is_ready()

Pre-flight check, inspect availability of self.tools

transform(model)

Transform the given model

• Transform symbols according to yace.transformation.CStyle

That it currently the only thing done to the yace IR.

sugar

Addition to ctypes, making it slightly nicer to use, including:

• gen_search_paths(libname) * find_library() + pkg-config

• load(libname)

• typedef additions * c_log_double_t * c_uint128 * c_int128 * void

TODO

• Dict-accessor for structs / unions

• Convenient typecast-helpers

Copyright (c) 2023 Simon A. F. Lund <os@safl.dk> SPDX-License-Identifier: BSD-3-Clause

class yace.targets.ctypes.ctypes_sugar.Enum

Encapsulation of C enum

class yace.targets.ctypes.ctypes_sugar.Structure

Encapsulation of C structs

class yace.targets.ctypes.ctypes_sugar.Union

Encapsulation of C union

yace.targets.ctypes.ctypes_sugar.c_int128

alias of c_ubyte_Array_16

yace.targets.ctypes.ctypes_sugar.c_long_double_t

alias of c_ubyte_Array_8

yace.targets.ctypes.ctypes_sugar.c_uint128

alias of c_ubyte_Array_16

yace.targets.ctypes.ctypes_sugar.gen_search_paths(libname)

Yields search-paths for the shared library with the given ‘libname’. It is an extension of ctypes.util.find_library() using pkg-config.

yace.targets.ctypes.ctypes_sugar.load(libname)

Dynamically load the shared library named ‘libname’