refactor: cull dead linker objects

[cpcloud]

Remove the ctypes linker and inline _LinkerBase methods since there is only a single linker class now.

Also removes _Linker.new since it is now redundant with the class's __init__ method.

[cpcloud]

/ok to test

[copy-pr-bot]

Auto-sync is disabled for ready for review pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.

[greptile-apps]

Greptile Overview

Greptile Summary

This PR successfully removes dead linker code by eliminating the unused CtypesLinker class and the _LinkerBase abstract base class. The refactoring consolidates all linker functionality into a single _Linker class, removing the now-unnecessary .new() factory method in favor of direct constructor calls.

Key changes:

• Removed ~150 lines of dead code (CtypesLinker class and _LinkerBase metaclass)
• Inlined abstract methods from _LinkerBase directly into _Linker with proper docstrings
• Replaced all _Linker.new() calls with direct _Linker() constructor calls
• Renamed Function class to CudaPythonFunction for better inspectability (with backward compatibility alias)
• All call sites properly updated with correct parameters

The refactoring is safe and maintains backward compatibility. All existing functionality is preserved.

Confidence Score: 5/5

• This PR is safe to merge with minimal risk - it's a clean refactoring that removes dead code without changing functionality
• The changes are straightforward: removing unused classes and inlining methods. All call sites have been properly updated to use the direct constructor instead of the factory method. The _Linker.__init__ signature remains unchanged with appropriate defaults (max_registers=None), ensuring backward compatibility. No logic changes were made, only code organization improvements.
• No files require special attention

Important Files Changed

File Analysis

Filename	Score	Overview
numba_cuda/numba/cuda/cudadrv/driver.py	5/5	Removed CtypesLinker class and _LinkerBase abstract base class, inlined methods into _Linker, and renamed Function to CudaPythonFunction for better inspectability
numba_cuda/numba/cuda/codegen.py	5/5	Updated two _Linker.new() calls to use direct _Linker() constructor instead
numba_cuda/numba/cuda/memory_management/nrt.py	5/5	Updated _Linker.new() call to direct _Linker() constructor with explicit max_registers=0 parameter
numba_cuda/numba/cuda/tests/cudadrv/test_linker.py	5/5	Updated test calls from _Linker.new() to direct _Linker() constructor with explicit max_registers=0 parameter

[greptile-apps]

Additional Comments (1)

1. numba_cuda/numba/cuda/cudadrv/driver.py, line 2338-2347 (link)

   logic: The new() method contains dead code. Line 2338 hardcodes linker = _Linker, so the condition if linker is _Linker on line 2341 is always true, making the else block (lines 2343-2345) unreachable.

_{1 file reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[cpcloud]

/ok to test

[greptile-apps]

_{4 files reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}