EclEmma vs LLVM llvm-cov

EclEmma is a Java code coverage tool that brings coverage analysis into the Eclipse workbench. It supports local Java applications, Eclipse and RCP applications, Equinox OSGi, JUnit, TestNG, Eclipse plug-in and RAP tests, SWTBot tests, and Scala applications. Its Coverage view summarizes results by project and lets developers inspect methods; source editors highlight covered and uncovered code. Coverage summaries can use instruction, branch, line, method, type and cyclomatic complexity counters. Users can switch among coverage sessions or merge results from separate test runs. EclEmma imports JaCoCo.exec data and exports reports in HTML, XML or CSV, as well as JaCoCo execution data files. It is based on JaCoCo and can be installed through the Eclipse Marketplace Client, an update site or manually. The free plug-in is listed at free under the Eclipse Public License 2.0. It requires Eclipse 3.8 or higher, Java 1.5 or higher, and Eclipse Java development tools; the project states that it has no operating-system dependency. Its Eclipse integration focuses on individual developers, with JaCoCo integrations suggested for automated builds.

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.