GDB

Tips

First make sure the symbols are in the execution. For GCC you should use -g flag. For letting compiler to generate more warnings, use -Wall flag.

g++ -Wall -g file.cpp
gdb a.out
gdb --args a.out arg1 arg2

Setting the arguments inside GDB

set args arg1

Seeing the source code (TUI - Text User Interface)

gdb -tui
layout src
layout asm
layout reg

Enable/Disable TUI

tui enable
tui disable

By default it's empty. You need to run the program to see the code. You can press arrow up or down to scroll the source code.

Run a program

run

If you enter run again, it restart the execution.

Run from main

start

Stack trace

backtrace full

Next Statement

next
n

Step into a function

step

Finish current function

finish

Set a breakpoint

break line_number
break function_name

List breakpoints

info break

Clear a breakpoint

clear line_number
clear function_name

Watch a variable

watch variable

Remove a watch

First run

info watchpoint

To see watch number, then

delete watch_number

Refresh the screen

refresh

You can also use CTRL+L shortcut

Continue to next breakpoint

continue

Print variables

Let's assume we have:

vector<int> v{1, 2, 3};
int a1[3] = {1, 2, 3};
int* a2 = int[3]{1, 2, 3};

print variable
print v[0]
print v
print a1
print *a2@3

References

• GDB Tutorial