Scanner Rust Analyzer Benchmarks (Sprint 130)

Summary

• New fixtures under src/Scanner/__Tests/StellaOps.Scanner.Analyzers.Lang.Tests/Fixtures/lang/rust/ capture heuristic and fallback behaviours.
• RustLanguageAnalyzerBenchmark (see src/Scanner/__Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks) exercises the new fixtures and emits heuristic coverage metrics.
• March 2025 snapshot: heuristic detection covers 3 crates (reqwest, serde, tokio) vs competitor baseline (1 crate), yielding 300% relative coverage.

Running the benchmarks

# Build once in Release for accurate metrics
DOTNET_CLI_UI_LANGUAGE=en dotnet build src/Scanner/__Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks.csproj -c Release

# Dump heuristic output
DOTNET_CLI_UI_LANGUAGE=en dotnet run --no-build   --project src/Scanner/__Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks.csproj   -- --dump-heuristics

# Dump fallback binary output (bin provenance)
DOTNET_CLI_UI_LANGUAGE=en dotnet run --no-build   --project src/Scanner/__Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks.csproj   -- --dump-fallback

# Run benchmarks (optional)
DOTNET_CLI_UI_LANGUAGE=en dotnet run   --project src/Scanner/__Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks/StellaOps.Scanner.Analyzers.Lang.Rust.Benchmarks.csproj   -c Release

BenchmarkDotNet emits warnings when running against Debug builds. Use -c Release or set config.WithOptions(ConfigOptions.DisableOptimizationsValidator) if you need debugging traces.

Heuristic coverage comparison

Competitor baseline data lives in competitor-baseline.json alongside the heuristics fixture and is used by RustHeuristicCoverageComparisonTests.

Fallback binary snapshot

The opaque fixture is a stripped Rust binary: it carries no crate symbols, only the rustc standard-library source path (/rustc/<40 hex>/library/...). Since PCD-816 an ELF file without Rust evidence (a well-formed Rust legacy-mangled symbol or that path) is not reported at all, so the fallback applies only to Rust binaries whose crates cannot be recovered.

componentKey: bin::sha256:f2af833346fdb3e282786c37ee4592233624d9d355a49a687d2b9950c1b86935
metadata:
  binary.path    -> usr/local/bin/opaque_bin
  binary.sha256  -> f2af833346fdb3e282786c37ee4592233624d9d355a49a687d2b9950c1b86935
  provenance     -> binary
evidence:
  source=binary locator=usr/local/bin/opaque_bin sha256=f2af833346fdb3e282786c37ee4592233624d9d355a49a687d2b9950c1b86935

This snapshot is persisted in expected.json for repeatable regression tests.