How to use LLDB to debug C++ programs?

How to use LLDB to debug C++ programs? Install LLDB Start LLDB Use basic commands to run programs, view variables and set expressions Practical case: Debugging memory leaks Other tips

How to use LLDB to debug C++ programs

LLDB is a powerful debugger written specifically for C, C++ and Objective-C programs. It provides a rich set of commands and functions that allow you to gain insight into your program's execution.

Install LLDB

LLDB comes with Xcode, if you already have Xcode installed, no additional installation is required. Otherwise, you can download LLDB from the [LLVM download page](https://releases.llvm.org/download.html).

Starting LLDB

To debug a program in LLDB, use the following command:

lldb path/to/program.exe

This will start LLDB and load the program.

Basic commands

• run: Run the program.
• next: Execute the next line of code.
• step: Execute the next line of code and enter the function call.
• continue: Continue executing the program until a breakpoint or exception is encountered.
• break: Set a breakpoint at the specified line number or function name.
• disassemble: Disassemble the code near the specified function or address.

View variables

To view the value of a variable, use the p command. For example, to print the value of variable x, use:

p x

Set expression

You can use the expr command Set expressions and view their results. For example, to evaluate the expression x + y, use:

expr x + y

Practical example: Debugging memory leaks

To debug memory leaks using LLDB , please perform the following steps:

1. Set breakpoints in the program.
2. Run the program and execute to the breakpoint.
3. Use the image list command to list loaded images.
4. Use the image dump -addresses -heap command to dump the heap space being used.
5. Look for any large chunks of memory that were allocated but never freed.
6. Use the backtrace command to find the code path that allocates memory.

Other tips

• Use the help command to view the documentation for the command.
• You can find more information in the LLDB documentation: [LLDB Documentation](https://lldb.llvm.org/documentation.html).

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