russell@unturf.com
db29a08762
B&W print-friendly diagrams + tinkerpop-0001 + wave-3 proof sections. Squash of 94 local commits onto remote master.
1.2 KiB
1.2 KiB
| id | repo | severity | status | created |
|---|---|---|---|---|
| gyp-0001 | gyp | MEDIUM | PATCHED | 2026-03-23 |
Defect
File: pylib/gyp/input.py:1604
Pattern: child in path list membership + .index() in DFS cycle detection
Complexity: O(V²)
Language: Python
Description
GYP's DFS-based cycle detection maintains the current path as a Python list and checks for back-edges using child in path (a linear scan). When a cycle is found, .index() is called on the same list to find the cycle start, which is another linear scan. Both operations are O(path length), and since they are performed for every edge in the dependency graph, the total cost is O(V²) in the number of targets.
Fix
Replace: child in path and path.index(child)
With: child in path_set and path_index[child]
Data structure change: path: list → path: list + path_set: set + path_index: dict
Work required
- Patch in
defects/gyp/patch/gyp-0001-path-set.patch` - Unit test — asserts exact operation counts before/after (in
defects/gyp/unit/) - Integration test (in
defects/gyp/integration/) - Benchmark — before/after on V=100,200,400,800 (in
defects/gyp/bench/) - White paper section