stack_usage lldb script

stack_usage.py

import lldb

# put this in ~/.lldb/stack_usage/stack_usage.py.
# Load in .lldbinit with `command script import "~/.lldb/stack_usage/stack_usage.py"`
# At a breakpoint, you can then type `stack_usage` to get the current stats.

@lldb.command("stack_usage")
def _stack_usage(debugger, command, result, internal_dict):
    """Show current stack usage information"""
    target = debugger.GetSelectedTarget()
    process = target.GetProcess()
    thread = process.GetSelectedThread()

    # Get stack pointer from current frame
    frame = thread.GetSelectedFrame()
    sp = frame.GetSP()

    # Get stack region info
    res = lldb.SBCommandReturnObject()
    interpreter = debugger.GetCommandInterpreter()
    interpreter.HandleCommand("memory region $sp", res)
    
    # Parse memory region output to get stack bounds
    region_info = res.GetOutput().split('\n')[0]

    if '[' in region_info and ')' in region_info:
        bounds = region_info[region_info.find('[')+1:region_info.find(')')].split('-')
        if len(bounds) == 2:
            stack_start = int(bounds[0], 16)
            stack_end = int(bounds[1], 16)
            
            # Calculate usage
            total_size = stack_end - stack_start
            used_size = stack_end - sp
            free_size = total_size - used_size
            usage_percent = (used_size / total_size) * 100
            
            print(f"Stack Usage:")
            print(f"Total Size: {total_size:,} bytes")
            print(f"Used Size: {used_size:,} bytes") 
            print(f"Free Size: {free_size:,} bytes") 
            print(f"Usage: {usage_percent:.1f}%")
            return

    print("Could not determine stack usage")