Binary package “lcov” in ubuntu bionic

Summarise Code coverage information from GCOV

 LCOV is an extension of GCOV, a GNU tool which provides information about
 what parts of a program are actually executed (i.e. "covered") while running
 a particular test case. The extension consists of a set of Perl scripts
 which build on the textual GCOV output to implement the following enhanced
 functionality:
 .
  - HTML based output: coverage rates are additionally indicated using bar
    graphs and specific colors.
  - Support for large projects: overview pages allow quick browsing of
    coverage data by providing three levels of detail: directory view,
    file view and source code view.