v8-code-dump-parser

Parse V8 dump generated by --print-code or --print-opt-code or stringify it back.

API

codeDumpParser(dump)

codeDumpParser.parse(dump)

Parses string into a tree structure.

Turns this:

--- Raw source ---
(a, b) {
  return a - b;
};

--- Optimized code ---
optimization_id = 0
source_position = 144
kind = OPTIMIZED_FUNCTION
name = sub
stack_slots = 1
Instructions (size = 111)
0x1649c54c3e80     0  55             push rbp
// ... more code ...
0x1649c54c3edb    91  90             nop

Deoptimization Input Data (deopt points = 4)
 index  ast id    argc     pc
     0       3       0     35
     1       3       0     -1
     2       3       0     -1
     3       3       0     -1

Safepoints (size = 19)
0x1649c54c3ea3    35  1 (sp -> fp)       0

RelocInfo (size = 14)
0x1649c54c3e9f  code target (BUILTIN)  (0x1649c5425f80)
0x1649c54c3ea7  position  (164)
0x1649c54c3ecd  runtime entry  (deoptimization bailout 1)
0x1649c54c3ed2  runtime entry  (deoptimization bailout 2)
0x1649c54c3ed7  runtime entry  (deoptimization bailout 3)

--- End code ---
--- Raw source ---
// ... more ...

into this:

[
  {
    source: "(a, b) {\n  return a - b;\n};",
    optimizedCode: {
      optimization_id: "0",
      source_position: "144",
      kind: "OPTIMIZED_FUNCTION",
      name: "sub",
      stack_slots: "1",
      instructions: "Instructions (size = 111)\n0x1649c54c3e80     0  55             push rbp\n// ... more code ...\n0x1649c54c3edb    91  90             nop
      safepoints: "Safepoints (size = 19)\n0x1649c54c3ea3    35  1 (sp -> fp)       0",
      relocInfo: "RelocInfo (size = 14)\n0x1649c54c3e9f  code target (BUILTIN)  (0x1649c5425f80)\n0x1649c54c3ea7  position  (164)\n0x1649c54c3ecd  runtime entry  (deoptimization bailout 1)\n0x1649c54c3ed2  runtime entry  (deoptimization bailout 2)\n0x1649c54c3ed7  runtime entry  (deoptimization bailout 3)"
    },
  }
  // ...
]

codeDumpParser.stringify(sections)

Converts tree structure back into string.

Install

npm install v8-code-dump-parser

License

MIT