.. _lcov_code_coverage:

Code coverage with lcov
=======================

Prerequisites
-------------

The Linux gcov and lcov tools are fussy about gcc / g++ compiler
versions. As of this writing, Ubuntu 18.04 gcov / lcov work with these
toolchain versions:

$ gcc –version gcc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0 $ g++ –version
g++ (Ubuntu 8.3.0-6ubuntu1~18.04.1) 8.3.0

Refer to
https://askubuntu.com/questions/26498/how-to-choose-the-default-gcc-and-g-version
for information on how to install multiple gcc / g++ versions, and
switch between them.

You’ll need to install the following additional packages:

$ sudo apt-get install gcovr ggcov lcov

Compile an instrumented vpp image
---------------------------------

Two ways:

$ cd $ make test-gcov $ ## interrupt compilation after building the
image

or $ cd /build-root $ make PLATFORM=vpp TAG=vpp_gcov vpp-install

Initialize the lcov database
----------------------------

$ cd $ ./extras/lcov/lcov_prep $ make test-gcov or make TEST=my_test
test-gcov $ # repeat or vary as desired to increase reported coverage $
# Generate the report: $ ./extras/lcov/lcov_post

You can run vpp manually, do anything you like. Results are cumulative
until you re-run the “prep” script.

Look at the results
-------------------

Point a browser at file:////build-root/html/index.html
