VS code is ignoring the breakpoint in c++ debugging

I am debugging a c++ code in VS Code but it doesn't stop on breakpoint and visualize the variables, watch and call stack, which it was supposed to do. Instead of this, it prints this in debug console:

Breakpoint 1, 0x000000000040074a in main ()
[Inferior 1 (process 9445) exited normally]
The program '/home/hashir/x/a.out' has exited with code 0 (0x00000000)

here is launch.json file:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "(gdb) Launch",
            "type": "cppdbg",
            "request": "launch",
            "program": "/home/hashir/x/a.out",
            "args": [],
            "stopAtEntry": false,
            "cwd": "/home/hashir/x/",
            "environment": [],
            "externalConsole": true,
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                }
            ]
        }
    ]
}

Comiple the program using -g tag alongwith g++/clang++