Must Know Lcov 使い方 Ideas

Swarming Logic Line coverage report using gcov/lcov from www.swarminglogic.com

Introduction

If you're a software developer, you know how important it is to test your code for bugs and errors. But how do you know if you've tested all the important parts of your code? That's where code coverage tools come in. Lcov is one such tool that helps you measure the quality of your testing by showing you which parts of your code have been tested and which haven't. In this tutorial, we'll explain what Lcov is, how it works, and how to use it effectively to improve the quality of your code.

What is Lcov?

Lcov is a code coverage tool for Linux that measures the quality of your testing by showing you which parts of your code have been executed during testing. It works by analyzing the output of your test suite and generating a report that shows you how much of your code has been covered by your tests. Lcov is based on the gcov tool, which is part of the GNU Compiler Collection (GCC).

How Does Lcov Work?

Lcov works by analyzing the output of your test suite, which should be compiled with the --coverage option. This option generates a special file that contains information about which parts of your code have been executed during testing. Lcov then reads this file and generates a report that shows you how much of your code has been covered by your tests. The report is typically displayed as an HTML file that you can view in your web browser.

Installing Lcov

Before you can use Lcov, you need to install it on your Linux system. You can do this using your package manager. For example, on Ubuntu, you can install Lcov using the following command:

sudo apt-get install lcov

Using Lcov

Once you have installed Lcov, you can start using it to measure the quality of your testing. Here are the basic steps:

Step 1: Compile Your Code with Coverage Options

To use Lcov, you need to compile your code with the --coverage option. For example:

gcc -o myprogram myprogram.c --coverage

This will generate a special file called myprogram.gcda that contains information about which parts of your code have been executed during testing.

Step 2: Run Your Test Suite

Next, you need to run your test suite. This will generate another special file called myprogram.gcno that contains information about which parts of your code are potentially executable.

Step 3: Generate Lcov Reports

Finally, you can use Lcov to generate reports that show you how much of your code has been covered by your tests. To do this, use the following command:

lcov --directory . --capture --output-file coverage.info

This will generate a file called coverage.info that contains information about your code coverage. You can then use the genhtml command to generate an HTML report:

genhtml coverage.info --output-directory coverage-report

This will create an HTML report in the coverage-report directory that you can view in your web browser.

Conclusion

In this tutorial, we've explained what Lcov is, how it works, and how to use it effectively to measure the quality of your testing. By using Lcov, you can identify which parts of your code have not been adequately tested and improve your testing strategy accordingly. We hope this tutorial has been helpful in getting you started with Lcov.