SourceBasedCodeCoverage.rst

Source-based Code Coverage

• Introduction
• The code coverage workflow
• Compiling with coverage enabled
• Running the instrumented program
• Creating coverage reports
• Format compatibility guarantees

Introduction

This document explains how to use clang's source-based code coverage feature. It's called "source-based" because it operates on AST and preprocessor information directly. This allows it to generate very precise coverage data.

Clang ships two other code coverage implementations:

• :doc:`SanitizerCoverage` - A low-overhead tool meant for use alongside the various sanitizers. It can provide up to edge-level coverage.
• gcov - A GCC-compatible coverage implementation which operates on DebugInfo.

From this point onwards "code coverage" will refer to the source-based kind.

The code coverage workflow