Coverlet vs LLVM llvm-cov

Coverlet is a free, MIT-licensed code coverage framework for modern .NET SDK-style projects. It measures line, branch, and method coverage across Linux, macOS, and Windows. Before tests execute, Coverlet instruments assemblies, records sequence-point hits, restores the original assemblies, and writes coverage results. Drivers are available for Microsoft Testing Platform, the .NET global tool, VSTest, and MSBuild. The Microsoft Testing Platform driver can emit JSON, LCOV, OpenCover, and Cobertura reports. Depending on the driver, teams can merge reports, validate coverage thresholds, and support deterministic builds. Collector and MSBuild packages use VSTest; Microsoft Testing Platform projects instead use coverlet.MTP, which requires the .NET 8.0 SDK or newer. Cake.Coverlet and Visual Studio viewing extensions are also listed. Coverage gates are supported, and bugs or feature requests go through the repository issues section.

LLVM llvm-cov is a free, self-hosted developer tool for examining coverage in instrumented C, C++, Objective-C, and Objective-C++ programs. It accepts executables, object files, dynamic libraries, or archives and works with gcov-style data or Clang instrumentation-based profiling. Its commands include gcov, show, report, and export. Show provides line-level coverage and can focus on selected source files. Report summarizes measurements such as branch, function, and MC/DC statistics; documented coverage types also include instantiation and region coverage. Output can be text, HTML, JSON, or LCOV. JSON exports may contain regions, functions, branches, expansions, and summaries. A typical workflow builds an instrumented program, runs it to create profile data, then uses llvm-profdata merge before analysis. The gcov command is compatible with gcov from GCC 4.2 and may work with later versions. LLVM documents llvm-cov as part of its developer toolchain. It runs on Linux, macOS, and Windows and has no paid plans or stated usage limits.