Follow the shape-vector provenance walk through user-function returns (wala/ML#706)

[khatchad]

Closes wala#706.

The shape-vector provenance walk (wala#703, #552) was intraprocedural, so a shape list produced by a user helper (the BERT/ALBERT get_shape_list pattern) stopped it at the helper's invoke and reported ⊤; one context additionally leaked the input tensor's shape through Reshape's fallback because the chain check didn't recognize the helper form.

What Changed

• getShapesOfShapeVector resolves a helper invoke's call-graph targets and walks every callee's returned value through the same chain recognition, unioning across callees and returns and falling back to ⊤ when any return doesn't resolve. No explicit parameter-to-argument mapping is needed: the callee parameter's interprocedural points-to set already holds the caller's allocation, so the .shape base case resolves across the boundary. A visited set threaded through the recursion guards recursive helpers.
• isShapeVectorChain mirrors the interprocedural case (and now takes the builder), so the legacy pin's skip case and Reshape's ⊤-guard recognize the helper form.

Coverage

testShapeHelperSlice pins the precise (5, 6) for get_shape(t)[-2:]. testShapeHelperSliceVar combines the hop with the negated variable bound from #553 (get_shape(t)[-k:]), which is structurally NLPGNN's einsum_via_matmul shape read (get_shape_list(input_tensor)[-num_inner_dims:]).

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR extends TensorFlow shape-vector provenance in the Python tensor analysis so that shape lists produced by user helper functions (e.g., get_shape_list-style helpers) are followed interprocedurally through callee returns, preventing premature ⊤ results and avoiding reshape fallback leaks when the helper form is involved.

Changes:

• Add interprocedural handling to TensorGenerator.getShapesOfShapeVector by walking call-graph targets and analyzing each callee’s returned value(s), with recursion guarding via a visited set.
• Extend TensorGenerator.isShapeVectorChain to mirror the interprocedural helper-return case (now requiring the call-graph builder).
• Add two new Python fixtures and corresponding JUnit tests to cover helper-return slicing with both literal and negated-variable slice bounds.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
com.ibm.wala.cast.python.ml/source/com/ibm/wala/cast/python/ml/client/TensorGenerator.java	Implements interprocedural shape-vector provenance via callee-return walking and updates shape-vector structural recognition accordingly.
com.ibm.wala.cast.python.ml/source/com/ibm/wala/cast/python/ml/client/PythonTensorAnalysisEngine.java	Updates the shape-vector structural check call site to pass the builder after the signature change.
com.ibm.wala.cast.python.test/data/tf2_test_shape_helper_slice.py	Adds a fixture covering helper-return [-2:] slicing feeding tf.reshape.
com.ibm.wala.cast.python.test/data/tf2_test_shape_helper_slice_var.py	Adds a fixture combining helper-return provenance with [-k:] (negated variable bound) slicing.
com.ibm.wala.cast.python.ml.test/source/com/ibm/wala/cast/python/ml/test/TestTensorflow2Model.java	Adds tests validating precise (5, 6) inference for both new helper fixtures.

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[codecov]

Codecov Report

❌ Patch coverage is 71.18644% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.32%. Comparing base (2fa3f54) to head (a7b1459).

Files with missing lines	Patch %	Lines
...bm/wala/cast/python/ml/client/TensorGenerator.java	68.51%	1 Missing and 16 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #554      +/-   ##
============================================
+ Coverage     74.31%   74.32%   +0.01%     
- Complexity     3591     3601      +10     
============================================
  Files           304      304              
  Lines         23341    23391      +50     
  Branches       3966     3985      +19     
============================================
+ Hits          17346    17386      +40     
+ Misses         4388     4385       -3     
- Partials       1607     1620      +13     

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

[khatchad]

❌ Patch coverage check failed.

The uncovered lines are the interprocedural walk's sound-fallback guards: the bare-return and recursive-helper rejections, the callee-without-IR and no-return degradations, and their mirrors in the structural chain check. Forcing them requires helpers whose degenerate form (return without a value feeding a shape position, self-recursive shape helpers) makes the fixture's own runtime assertions unreachable or invalid. The behavioral paths are covered by testShapeHelperSlice and testShapeHelperSliceVar.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.