├── .flake8
├── README.md
└── stack-inspector.py


/.flake8:
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1 | [flake8]
2 | max-line-length = 100
3 | 


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/README.md:
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 1 | # stack-inspector
 2 | 
 3 | A `gdb` command to inspect the size of objects on the stack.
 4 | 
 5 | ![](https://i.imgur.com/uiDEJab.png)
 6 | 
 7 | ## how to
 8 | 
 9 | Use `gdb` to navigate to a certain stack frame (run until your stack overflows or set a breakpoint somewhere). Then, simply run:
10 | ```gdb
11 | source stack-inspector.py
12 | stack-inspector
13 | ```
14 | 


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/stack-inspector.py:
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  1 | import gdb
  2 | from collections import OrderedDict, namedtuple
  3 | 
  4 | 
  5 | ANSI_BOLD = "\x1b[1m"
  6 | ANSI_GREEN = "\x1b[32m"
  7 | ANSI_MAGENTA = "\x1b[35m"
  8 | ANSI_CYAN = "\x1b[36m"
  9 | ANSI_RESET = "\x1b[0m"
 10 | 
 11 | 
 12 | Symbol = namedtuple('Symbol', ['size', 'typename'])
 13 | 
 14 | 
 15 | def analyze_frame(frame_nr, frame):
 16 |     info = frame.find_sal()
 17 | 
 18 |     if info.symtab:
 19 |         if frame.function():
 20 |             function_name = frame.function().name
 21 |         else:
 22 |             function_name = "?"
 23 |         print("  {bold}#{frame_nr:<3}{reset} "
 24 |               "{green}{function}{reset}"
 25 |               " @ "
 26 |               "{filename}:{line}\n".format(
 27 |                 frame_nr=frame_nr,
 28 |                 filename=info.symtab.filename,
 29 |                 line=info.line,
 30 |                 function=function_name,
 31 |                 bold=ANSI_BOLD,
 32 |                 green=ANSI_GREEN,
 33 |                 reset=ANSI_RESET))
 34 |     else:
 35 |         print("  {bold}#{frame_nr:<3}{reset} Could not retrieve frame information\n".format(
 36 |             frame_nr=frame_nr,
 37 |             bold=ANSI_BOLD,
 38 |             green=ANSI_GREEN,
 39 |             reset=ANSI_RESET))
 40 |         return
 41 | 
 42 |     try:
 43 |         block = frame.block()
 44 |     except RuntimeError:
 45 |         print("Could not retrieve block information")
 46 |         return
 47 | 
 48 |     if frame.type() == gdb.INLINE_FRAME:
 49 |         print("    Frame is inlined.")
 50 |         print()
 51 |         return
 52 | 
 53 |     symbols = {}
 54 |     while block:
 55 |         if not (block.is_global or block.is_static):
 56 |             for symbol in block:
 57 |                 # We only show symbols which are on the call stack
 58 |                 # - function arguments
 59 |                 # - local variables (which need frame information, no static variables)
 60 |                 if symbol.is_argument or \
 61 |                         (symbol.is_variable and symbol.addr_class != gdb.SYMBOL_LOC_STATIC):
 62 |                     if symbol.name not in symbols:
 63 |                         symbols[symbol.name] = Symbol(symbol.type.sizeof, symbol.type)
 64 | 
 65 |         block = block.superblock
 66 | 
 67 |     symbols = OrderedDict(sorted(symbols.items(),
 68 |                                  key=lambda s: s[1].size,
 69 |                                  reverse=True))
 70 | 
 71 |     total_size = 0
 72 |     for name, (size, typename) in symbols.items():
 73 |         print("    {bold}{size:>14,}{reset}   {name} ({cyan}{typename}{reset})".format(
 74 |                 size=size,
 75 |                 name=name,
 76 |                 typename=typename,
 77 |                 cyan=ANSI_CYAN,
 78 |                 magenta=ANSI_MAGENTA,
 79 |                 bold=ANSI_BOLD,
 80 |                 reset=ANSI_RESET
 81 |                 ))
 82 |         if size:
 83 |             total_size += size
 84 | 
 85 |     print()
 86 | 
 87 |     return total_size
 88 | 
 89 | 
 90 | class StackVisualizer(gdb.Command):
 91 |     """Inspect the stack for large objects"""
 92 | 
 93 |     def __init__(self):
 94 |         super(StackVisualizer, self).__init__("stack-inspector", gdb.COMMAND_STACK)
 95 | 
 96 |     def invoke(self, arg, from_tty):
 97 |         try:
 98 |             frame = gdb.selected_frame()
 99 |         except gdb.error:
100 |             print("[stack-inspector] could not retrieve frame information (no stack).")
101 |             return
102 | 
103 |         backtrace = []
104 | 
105 |         while frame:
106 |             backtrace.append(frame)
107 |             frame = frame.older()
108 | 
109 |         print()
110 |         total_size = 0
111 |         for frame_nr, frame in enumerate(backtrace):
112 |             frame_size = analyze_frame(frame_nr, frame)
113 |             if frame_size:
114 |                 total_size += frame_size
115 | 
116 |         print("Total size: {size:,}".format(size=total_size))
117 | 
118 | 
119 | StackVisualizer()
120 | 


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