russell@unturf.com
db29a08762
B&W print-friendly diagrams + tinkerpop-0001 + wave-3 proof sections. Squash of 94 local commits onto remote master.
1.1 KiB
1.1 KiB
| id | repo | severity | status | created |
|---|---|---|---|---|
| swift-0001 | swift | LOW | NOT-WORTH-FIXING | 2026-03-23 |
Defect
File: lib/Sema/RewriteContext.cpp:454
Pattern: assert-only visited check, debug builds only
Complexity: O(n)
Language: C++
Description
The rewrite context in Swift's semantic analysis uses a linear scan to verify that a node has not been visited twice, but this check exists only within an assert() macro and is therefore compiled out in release builds. In debug builds, the O(n) scan is performed per node visit for sanity checking, slowing down debug-mode compilation for large files. There is no correctness impact in production builds.
Fix
Replace: linear scan inside assert(...)
With: assert(visitedSet.insert(node).second)
Data structure change: visited: SmallVector → visitedSet: llvm::SmallPtrSet
Work required
- Patch in
defects/swift/patch/ - Unit test — asserts exact operation counts before/after (in
defects/swift/unit/) - Integration test (in
defects/swift/integration/) - Benchmark — before/after on V=100,200,400,800 (in
defects/swift/bench/) - White paper section