[Yuhx141]

Private functions passed to make_closure still need their original definitions and call signatures. These passes previously updated direct calls only and could remove or replace a function while leaving its closure reference behind.

• retain value-referenced functions in InlinePrivateFunctions;
• retain their tuple parameter signatures in ExpandTupleArguments;
• retain their original parameters and GlobalVar identity in RemoveUnusedParameters.

The three passes share a small internal reference collector. Functions used only by direct calls remain eligible for the existing optimizations.

Closes #20593
Closes #20653
Closes #20654

Tests:

• All three added closure regressions fail on unmodified main.
• pytest tests/python/relax/test_transform_inline_private_functions.py tests/python/relax/test_transform_expand_tuple_args.py tests/python/relax/test_transform_remove_unused_parameters.py -q: 12 passed, including the existing direct-call and recursion controls.
• Release/LLVM build completed for the three modified C++ passes.
• Pre-commit passed on all seven PR files.

[Yuhx141]

Hi @tlopex, could you review this Relax closure-reference correctness fix when you have a chance? It preserves functions referenced by make_closure, including their signatures and GlobalVar identity, across InlinePrivateFunctions, ExpandTupleArguments, and RemoveUnusedParameters. The three focused closure regressions and existing direct-call controls are included, and the current CI checks are green. Thanks!

[Yuhx141]

Hi @tqchen, could you review this fix for closure-referenced private functions when you have a chance? It preserves their definitions and signatures across InlinePrivateFunctions, ExpandTupleArguments, and RemoveUnusedParameters. The five current CI checks are green. Thanks!

[Yuhx141]

Hi @tqchen @tlopex, could you review this closure-reference correctness fix when convenient? It preserves private functions and their signatures when referenced through make_closure across InlinePrivateFunctions, ExpandTupleArguments, and RemoveUnusedParameters. The focused regressions and direct-call controls are included, and the five currently reported CI contexts are successful. Thanks!