EclEmma vs gcov

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.

gcov is a free test coverage tool used with GCC to show how program code runs during testing. It reports which source lines execute and how often, producing per-line counts in `.gcov` files. Reports can include line, function, branch, condition, prime-path, and basic-block coverage. Options can report branch frequencies, show whether conditions independently affect a Boolean expression’s result, or filter reports to functions matching regular expressions. Output is available as `.gcov` text or gzip-compressed JSON; JSON generation does not require source code. The GCC documentation also describes using gcov with gprof to assess computing time, while warning that optimization can combine source lines and reduce hotspot detail. Before coverage reporting, programs must be compiled with GCC’s `--coverage` option. gcov works only with GCC-compiled code and is not compatible with other profiling or test coverage mechanisms. It runs on Linux, macOS, and Windows, supports the listed languages from C and C++ to Ada, D, and Go, and is self-hosted.