Enabling Debugging with CMake for a C++ Project

When developing a C++ project, debugging is an essential part of the process, as it allows you to identify and fix issues in your code. If you’re using CMake to build your project, it’s crucial to know how to enable debug mode to take advantage of debugging tools like gdb. In this post, we’ll walk you through the steps required to enable debugging with CMake and start using gdb to debug your compiled program.

Configure CMake with Debug Build Type

First, configure your CMake build with the CMAKE_BUILD_TYPE parameter set to Debug. This will ensure that CMake invokes gcc with the -g flag, which generates debugging information for your compiled program. To do this, navigate to your project’s root directory and run the following command:

cmake -DCMAKE_BUILD_TYPE=Debug .

This command tells CMake to generate a debug build configuration, including the necessary flags to enable debugging with tools like gdb.

Build Your Project

After configuring CMake with the Debug build type, you can build your project as usual. Navigate to your project’s build directory and run the build command:

make

This will build your project with the -g flag, generating the necessary debugging information.

Debug Your Program with gdb

Now that your program has been built with debugging information, you can use gdb to debug it. To do this, simply invoke gdb with the path to your compiled binary:

gdb path/to/your/binary

This will start gdb with your binary loaded, allowing you to set breakpoints, inspect variables, and step through your code.

Utilize gdb Commands for Debugging

Once you’re inside gdb, you can use various commands to control the debugging process:

• break <function_name>: Set a breakpoint at the specified function.
• run: Start the program execution.
• next: Execute the next line of code in the current function.
• step: Execute the next line of code, stepping into functions if necessary.
• continue: Continue program execution until the next breakpoint or the program exits.
• print <variable_name>: Display the value of a variable.
• watch <variable_name>: Set a watchpoint on a variable, pausing execution when its value changes.
• quit: Exit gdb.

By configuring CMake with the Debug build type, building your project with the -g flag, and utilizing gdb commands, you can efficiently debug your program and improve its quality.