resolve-jit-symbols

Resolves symbols for dynamic code generated by a JIT via a map file.

var resolveJITSymbols = require('resolve-jit-symbols');
var map = fs.readFileSync(__dirname + '/test/fixtures/jit.map', 'utf8')
  
var resolver = resolveJITSymbols(map);
var res = resolver.resolve('0x38852ffd485a');
console.log(res);

{ address        : '38852ffd4640',
  size           : '54c',
  decimalAddress : 62144686933568,
  symbol         : 'LazyCompile    : *go' }

Command Line

cat test/fixtures/callgraph.csv | rjs test/fixtures/jit.map

Installation

npm install resolve-jit-symbols

Usage

# Supply path to map file
cat callstack.csv | rjs /tmp/<perf-*.map>

# Or pid of process whose map file to use (resolved from /tmp/perf-<pid>.map)
cat callstack.csv | rjs <pid>

How to Generate JIT Symbol Files

Any tool that can generate the format described here will work.

With Node.js >=v0.11.15 do the following:

node --perf-basic-prof your-app.js

This will create a map file at /tmp/perf-<pid>.map.

API

JITResolver::hexAddressRegex

RegExp used to match memory addresses.

Source:

• index.js , lineno 124

JITResolver::lldb_backtraceRegex

RegExp used to match memory lldb backtraces of the form #1 0x001 in 0x001 () When calling var m = s.match(regex) m[1] contains first matched address and m[2] contains second matched address.

Source:

• index.js , lineno 131

JITResolver(map) → {Object}

Instantiates a JIT resolver for the given map.

Parameters:

Name	Type	Description
map	String | Array.<String>	either a string or lines with space separated HexAddress, Size, Symbol on each line

Source:

• index.js , lineno 31

Returns:

the initialized JIT resolver

Type

Object

JITResolver::resolve(hexAddress) → {Object}

Matches the address of the symbol of which the given address is part of.

Parameters:

Name	Type	Description
hexAddress	String | Number	the hexadecimal address of the address to check

Source:

• index.js , lineno 54

Returns:

info of the matching symbol which includes address, size, symbol

Type

Object

JITResolver::resolveMulti(stack, getHexAddress) → {Array.<String>|String}

Resolves all symbols in a given stack and replaces them accordingly

Parameters:

Name	Type	Argument	Description
stack	Array.<String> | String		string of stack or lines of stack
getHexAddress	function	<optional>	allows overriding the function used to find a hex address on each line, returns { address: 0x000, include: true|false }

Source:

• index.js , lineno 92

Returns:

the stack with symbols resolved in the same format that the stack was given, either as lines or one string

Type

Array.<String> | String

generated with docme

License

MIT