# frozen_string_literal: false #-- # $Release Version: 0.3$ # $Revision: 1.12 $ ## # Outputs a source level execution trace of a Ruby program. # # It does this by registering an event handler with Kernel#set_trace_func for # processing incoming events. It also provides methods for filtering unwanted # trace output (see Tracer.add_filter, Tracer.on, and Tracer.off). # # == Example # # Consider the following Ruby script # # class A # def square(a) # return a*a # end # end # # a = A.new # a.square(5) # # Running the above script using <code>ruby -r tracer example.rb</code> will # output the following trace to STDOUT (Note you can also explicitly # <code>require 'tracer'</code>) # # #0:<internal:lib/rubygems/custom_require>:38:Kernel:<: - # #0:example.rb:3::-: class A # #0:example.rb:3::C: class A # #0:example.rb:4::-: def square(a) # #0:example.rb:7::E: end # #0:example.rb:9::-: a = A.new # #0:example.rb:10::-: a.square(5) # #0:example.rb:4:A:>: def square(a) # #0:example.rb:5:A:-: return a*a # #0:example.rb:6:A:<: end # | | | | | # | | | | ---------------------+ event # | | | ------------------------+ class # | | --------------------------+ line # | ------------------------------------+ filename # ---------------------------------------+ thread # # Symbol table used for displaying incoming events: # # +}+:: call a C-language routine # +{+:: return from a C-language routine # +>+:: call a Ruby method # +C+:: start a class or module definition # +E+:: finish a class or module definition # +-+:: execute code on a new line # +^+:: raise an exception # +<+:: return from a Ruby method # # == Copyright # # by Keiju ISHITSUKA(keiju@ishitsuka.com) # class Tracer VERSION = "0.1.1" class << self # display additional debug information (defaults to false) attr_accessor :verbose alias verbose? verbose # output stream used to output trace (defaults to STDOUT) attr_accessor :stdout # mutex lock used by tracer for displaying trace output attr_reader :stdout_mutex # display process id in trace output (defaults to false) attr_accessor :display_process_id alias display_process_id? display_process_id # display thread id in trace output (defaults to true) attr_accessor :display_thread_id alias display_thread_id? display_thread_id # display C-routine calls in trace output (defaults to false) attr_accessor :display_c_call alias display_c_call? display_c_call end Tracer::stdout = STDOUT Tracer::verbose = false Tracer::display_process_id = false Tracer::display_thread_id = true Tracer::display_c_call = false @stdout_mutex = Thread::Mutex.new # Symbol table used for displaying trace information EVENT_SYMBOL = { "line" => "-", "call" => ">", "return" => "<", "class" => "C", "end" => "E", "raise" => "^", "c-call" => "}", "c-return" => "{", "unknown" => "?" } def initialize # :nodoc: @threads = Hash.new if defined? Thread.main @threads[Thread.main.object_id] = 0 else @threads[Thread.current.object_id] = 0 end @get_line_procs = {} @filters = [] end def stdout # :nodoc: Tracer.stdout end def on # :nodoc: if block_given? on begin yield ensure off end else set_trace_func method(:trace_func).to_proc stdout.print "Trace on\n" if Tracer.verbose? end end def off # :nodoc: set_trace_func nil stdout.print "Trace off\n" if Tracer.verbose? end def add_filter(p = nil, &b) # :nodoc: p ||= b @filters.push p end def set_get_line_procs(file, p = nil, &b) # :nodoc: p ||= b @get_line_procs[file] = p end def get_line(file, line) # :nodoc: if p = @get_line_procs[file] return p.call(line) end unless list = SCRIPT_LINES__[file] list = File.readlines(file) rescue [] SCRIPT_LINES__[file] = list end if l = list[line - 1] l else "-\n" end end def get_thread_no # :nodoc: if no = @threads[Thread.current.object_id] no else @threads[Thread.current.object_id] = @threads.size end end def trace_func(event, file, line, id, binding, klass, *) # :nodoc: return if file == __FILE__ for p in @filters return unless p.call event, file, line, id, binding, klass end return unless Tracer::display_c_call? or event != "c-call" && event != "c-return" Tracer::stdout_mutex.synchronize do if EVENT_SYMBOL[event] stdout.printf("<%d>", $$) if Tracer::display_process_id? stdout.printf("#%d:", get_thread_no) if Tracer::display_thread_id? if line == 0 source = "?\n" else source = get_line(file, line) end stdout.printf("%s:%d:%s:%s: %s", file, line, klass || '', EVENT_SYMBOL[event], source) end end end # Reference to singleton instance of Tracer Single = new ## # Start tracing # # === Example # # Tracer.on # # code to trace here # Tracer.off # # You can also pass a block: # # Tracer.on { # # trace everything in this block # } def Tracer.on if block_given? Single.on{yield} else Single.on end end ## # Disable tracing def Tracer.off Single.off end ## # Register an event handler <code>p</code> which is called every time a line # in +file_name+ is executed. # # Example: # # Tracer.set_get_line_procs("example.rb", lambda { |line| # puts "line number executed is #{line}" # }) def Tracer.set_get_line_procs(file_name, p = nil, &b) p ||= b Single.set_get_line_procs(file_name, p) end ## # Used to filter unwanted trace output # # Example which only outputs lines of code executed within the Kernel class: # # Tracer.add_filter do |event, file, line, id, binding, klass, *rest| # "Kernel" == klass.to_s # end def Tracer.add_filter(p = nil, &b) p ||= b Single.add_filter(p) end end # :stopdoc: SCRIPT_LINES__ = {} unless defined? SCRIPT_LINES__ if $0 == __FILE__ # direct call $0 = ARGV[0] ARGV.shift Tracer.on require $0 else # call Tracer.on only if required by -r command-line option count = caller.count {|bt| %r%/rubygems/core_ext/kernel_require\.rb:% !~ bt} if (defined?(Gem) and count == 0) or (!defined?(Gem) and count <= 1) Tracer.on end end # :startdoc: