reconstitute-perf-symbols.rb

#!/usr/bin/env ruby

if ARGV.length < 3
  STDERR.puts("usage: #{$0} 'line_match' <perf.script.file> <symbol_file>")
  STDERR.puts("line_match is a string submatch for a line line:")
  STDERR.puts
  STDERR.puts("	          40b1c5 [unknown] (/usr/local/bin/foobar (deleted))")
  STDERR.puts
  STDERR.puts("symbol_file is the output of `objdump -Tt /path/to/executable`")

  exit 1
end

line_match = ARGV[0]
trace_file = ARGV[1]
symbol_file = ARGV[2]

symbols = []

File.open(symbol_file) do |f|
  f.each_line do |l|
    l.strip!

    fields = l.split(/\s+/)
    # looking for lines like:
    # 000000000042d620 g     F .text	000000000000012b              runtime.Stack
    if fields.length < 6
      next
    end

    if fields[3] != '.text'
      next
    end


    # append addr and function_name
    symbols << [fields[0].to_i(16), fields[5]]
  end
  symbols << [0xffffffffffffffff, 'END_SYMBOL']
end

symbols.sort! {|a,b| a[0] <=> b[0] }

File.open(trace_file) do |f|
  f.each_line do |l|

    if l.include?(line_match)
      parts = l.strip.split(/\s+/)
      addr = parts[0].to_i(16)
      idx = symbols.bsearch_index {|s| s[0] >= addr }
      if idx
       print l.sub("[unknown]", symbols[idx-1][1])
      else
       print l
      end
    else
     print l
    end
  end
end