diff --git a/ext/objspace/lib/objspace/trace.rb b/ext/objspace/lib/objspace/trace.rb new file mode 100644 index 0000000000..df803bbae6 --- /dev/null +++ b/ext/objspace/lib/objspace/trace.rb @@ -0,0 +1,44 @@ +# This is a simple tool to enable the object allocation tracer. +# When you have an object of unknown provenance, you can use this +# to investigate where the object in question is created. +# +# = Important notice +# +# This is only for debugging purpose. Do not use this in production. +# Require'ing this file immediately starts tracing the object allocation, +# which brings a large performance overhead. +# +# = Usage +# +# 1. Add `require "objspace/trace"` into your code (or add `-robjspace/trace` into the command line) +# 2. `p obj` will show the allocation site of `obj` +# +# Note: This redefines `Kernel#p` method, but not `Object#inspect`. +# +# = Examples +# +# 1: require "objspace/trace" +# 2: +# 3: obj = "str" +# 4: +# 5: p obj #=> "str" @ test.rb:3 + +require 'objspace.so' + +module Kernel + define_method(:p) do |*objs| + objs.each do |obj| + file = ObjectSpace.allocation_sourcefile(obj) + line = ObjectSpace.allocation_sourceline(obj) + if file + puts "#{ obj.inspect } @ #{ file }:#{ line }" + else + puts obj.inspect + end + end + end +end + +ObjectSpace.trace_object_allocations_start + +warn "objspace/trace is enabled" diff --git a/test/objspace/test_objspace.rb b/test/objspace/test_objspace.rb index 7032798940..7797d199fa 100644 --- a/test/objspace/test_objspace.rb +++ b/test/objspace/test_objspace.rb @@ -616,4 +616,20 @@ class TestObjSpace < Test::Unit::TestCase assert_not_include ObjectSpace.dump(Class.new), '"name"' assert_not_include ObjectSpace.dump(Module.new), '"name"' end + + def test_objspace_trace + assert_in_out_err(%w[-robjspace/trace], "#{<<-"begin;"}\n#{<<-'end;'}") do |out, err| + begin; + a = "foo" + b = "b" + "a" + "r" + c = 42 + p a, b, c + end; + assert_equal 3, out.size + assert_equal '"foo" @ -:2', out[0] + assert_equal '"bar" @ -:3', out[1] + assert_equal '42', out[2] + assert_equal ["objspace/trace is enabled"], err + end + end end