1 files changed, 45 insertions, 0 deletions
diff --git a/ext/objspace/lib/objspace/trace.rb b/ext/objspace/lib/objspace/trace.rb
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+++ b/ext/objspace/lib/objspace/trace.rb
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+# 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
+  remove_method :p
+  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"