Verify autoformatter recursion limit fix (already resolved upstream)

[Copilot]

The autoformatter was hitting Python's recursion limit on structs/enums with many fields/entries. The compiler front end was previously fixed, but the formatter was not.

Status: Already Fixed

This issue was resolved upstream in google/emboss PR google#215 (Dec 2024). The fix is already present in this fork.

Implementation

• compiler/util/parser_util.py - New iterative transform_parse_tree() using explicit stack instead of recursion
• compiler/front_end/format_emb.py - Updated to use parser_util.transform_parse_tree
• compiler/front_end/module_ir.py - Updated to use parser_util.transform_parse_tree

The iterative approach eliminates the recursion limit entirely (up to available memory):

# Stack-based traversal instead of recursive calls
stack = [(parse_tree, None, False, None)]
while True:
    node, parent, children_completed, transformed_children = stack.pop()
    # ... process node iteratively

Verification

Tests pass with 32k+ entity files (2x the Python default recursion limit):

• FormatEmbTest.test_very_long_emb ✓
• ModuleIrTest.test_long_input ✓

No code changes needed—closing as resolved.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Autoformatter Hits Python Recursion Limit on structs/enums with many fields/entries</issue_title>
<issue_description>This issue was copied from the upstream repository google/emboss.

Original issue: google#34
Original state: open, created at: 2022-02-15T23:18:39Z, updated at: 2024-07-22T14:24:03Z, by @reventlov

---

Original description

The compiler front end was previously fixed to avoid deep recursion, but the autoformatter was not.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Autoformatter Hits Python Recursion Limit on structs/enums with many fields/entries #84

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.