What is the name of the tool?
Floyd (floyd and cargo-floyd crates)
Add a concise description of the tool. Please refrain from marketing claims and stick to what the tool is, does, and how it would be used?
Floyd is an external MC/DC (Modified Condition/Decision Coverage) engine for Rust. It recovers logical decisions from rustc MIR and analyses them under masking MC/DC, riding on the existing -Cinstrument-coverage -Zcoverage-options=branch,condition instrumentation and ingesting profraw via llvm-profdata and llvm-cov. It does not fork rustc, by design. Output is per-condition exercised and unexercised pairs, with JSON and JUnit XML for CI.
rustc's own -Zcoverage-options=mcdc instrumentation was removed in August 2025, and there is currently no cargo-native open-source MC/DC tool, so Floyd is built to fill that gap. It targets ISO 26262 TCL3 via qualification-by-validation, using a differential corpus of pinned, hand-computed analyses as the evidence artifact, with CI failing on any drift between engine output and ground truth.
Usage is cargo install cargo-floyd, then running it over a crate to obtain MC/DC coverage results suitable as structural-coverage evidence for ISO 26262 or DO-178C work. Current scope recovers boolean expressions, inline comparisons, if-let bindings, the ? success path, literal/bool/enum match, let-bound booleans, and Fn/move closures; it declines match guards, multi-value destructuring, async desugaring, and FnMut-with-internal-mutation, returning no decision rather than a wrong one.
Link to the tool repo or homepage
https://github.com/Gordion-Solutions/Floyd
License of the tool
MIT or Apache 2.0
What is your role/connection to this tool?
Creator/Maintainer (open source)
Optional name of the tool vendor
www.gordionsolutions.co.uk
Optional liability provided by the tool vendor
None
List any standards the tool is qualified for
None yet. Floyd targets ISO 26262 (ASIL-D, TCL3) and is designed for qualification-by-validation, but is not yet formally qualified.
Tool category
code-coverage
What is the name of the tool?
Floyd (floyd and cargo-floyd crates)
Add a concise description of the tool. Please refrain from marketing claims and stick to what the tool is, does, and how it would be used?
Floyd is an external MC/DC (Modified Condition/Decision Coverage) engine for Rust. It recovers logical decisions from rustc MIR and analyses them under masking MC/DC, riding on the existing -Cinstrument-coverage -Zcoverage-options=branch,condition instrumentation and ingesting profraw via llvm-profdata and llvm-cov. It does not fork rustc, by design. Output is per-condition exercised and unexercised pairs, with JSON and JUnit XML for CI.
rustc's own -Zcoverage-options=mcdc instrumentation was removed in August 2025, and there is currently no cargo-native open-source MC/DC tool, so Floyd is built to fill that gap. It targets ISO 26262 TCL3 via qualification-by-validation, using a differential corpus of pinned, hand-computed analyses as the evidence artifact, with CI failing on any drift between engine output and ground truth.
Usage is cargo install cargo-floyd, then running it over a crate to obtain MC/DC coverage results suitable as structural-coverage evidence for ISO 26262 or DO-178C work. Current scope recovers boolean expressions, inline comparisons, if-let bindings, the ? success path, literal/bool/enum match, let-bound booleans, and Fn/move closures; it declines match guards, multi-value destructuring, async desugaring, and FnMut-with-internal-mutation, returning no decision rather than a wrong one.
Link to the tool repo or homepage
https://github.com/Gordion-Solutions/Floyd
License of the tool
MIT or Apache 2.0
What is your role/connection to this tool?
Creator/Maintainer (open source)
Optional name of the tool vendor
www.gordionsolutions.co.uk
Optional liability provided by the tool vendor
None
List any standards the tool is qualified for
None yet. Floyd targets ISO 26262 (ASIL-D, TCL3) and is designed for qualification-by-validation, but is not yet formally qualified.
Tool category
code-coverage