#!/usr/bin/ruby -Ke
#
# backtrace.rb: resolve symbols in T-Monitor backtrace(btr) output
# 
#    Usage:
#
#      1. (Optional) Set environment variable LD_BACKTRACE_TKERNEL to
#         where you want to find *.so files from which to resolve symbols
#           e.g., export LD_BACKTRACE_TKERNEL=$QTDIR:$BD/lib/pcat.dl
#
#      2. Run "backtrace.rb <executable-file>"
#
#      3. (Optional), copy&paster "ref dyn <pid>" output to stdin as well
#      4. Copy&paste "btr" command output to stdin
#           - 3. and 4. can be done at the same time, as garbage 
#             lines (like [/SYS]% ...) are correctly ignored
#
#      5. Press Ctrl+D to close stdin
#      6. See what happens :-)
#

$inputs = []
$output = ""
$cnt = 0
$syms = []
$dirs = []

$regex_btrhead = /^TM\>\s*[bB][tT][rR]\s*/
$regex_btrbody = /^\s*(<--|EIP\s*=)\s*([0-9a-fA-F]{8})\s*$/

def searchSymbol(addr)
  sv = ""
  $syms.each do |elem|
    if elem[0] > addr then
      break
    end
    sv = elem[1] + " + " + (addr - elem[0]).to_s
  end
  return sv
end

def loadSymbols(file, offset)
  IO.popen("nm -Cn #{file}", "r") do |mapfile|
    mapfile.each do |line|
      line.chomp!
      if /^\s*([0-9a-fA-F]{8})\s+[TtWw]\s+(.+?)\s*$/ =~ line then
        $syms << [$1.hex + offset, $2]
      end
    end
  end
  $syms.sort!
end

def main()
  if ARGV.length != 1 then
    print "Usage: backtrace.rb <executable-file>\n"
    exit 1
  end

  if ENV.has_key?('LD_BACKTRACE_TKERNEL') then
    $dirs = ENV['LD_BACKTRACE_TKERNEL'].split(':').delete_if {|x| x == ""}
  end

  # Symbols in executable itself maps as it is (offset = 0)
  loadSymbols(ARGV[0], 0)

  STDIN.each do |line|
    if $regex_btrhead =~ line || $regex_btrbody =~ line then
      $inputs << line
    elsif /^\s*0x([0-9a-fA-F]{8})\s+-\s+[0-9]+\+[0-9]+\s+(lib[a-zA-Z0-9_]+\.so[.0-9]*)\s*$/ =~ line then
      dir = $dirs.find {|x| File.exist?("#{x}/#{$2}")}
      if dir != nil then
        loadSymbols("#{dir}/#{$2}", $1.hex)
      else
        $stderr.print "Warning: #{$2} not found\n"
      end
    end
  end

  $inputs.each do |line|
    line.chomp!
    if $regex_btrhead =~ line then
      $output += "<<backtrace>>\n"
      $cnt = 0
    elsif $regex_btrbody =~ line
      addr = $2.hex
      $output += sprintf("[%02d] : %08x : %s\n", $cnt, addr, searchSymbol(addr))
      $cnt = $cnt+1
    end
  end

  print "#{$output}"
end

main()