Bug #18886
Updated by ioquatix (Samuel Williams) almost 2 years ago
Given the following program, `thing.name` and `thing.shape` don't trigger `c_call` trace points (or any trace points actually). ```ruby pp RUBY_VERSION trace_point = TracePoint.new(:line, :call, :c_call, :a_call) do |trace| puts trace.event if trace.event == :call # Ruby doesn't always mark call-sites in sub-expressions, so we use this approach to compute a call site and mark it: if location = caller_locations(2, 1).first and path = location.path puts "> #{path}:#{location.lineno}:#{trace.event}" #{path}:#{location.lineno}:#{trace.event}:#{trace.method_id}" end end if path = trace.path puts "= #{path}:#{trace.lineno}:#{trace.event}" #{path}:#{trace.lineno}:#{trace.event}:#{trace.method_id}" end end trace_point.enable # This will trigger call trace points # class Thing # def name # :cat # end # def shape # :square # end # end # thing = Thing.new # Thing = Struct.new(:name, :shape) # thing = Thing.new(:cat, :rectangle) [ name: thing.name, shape: thing.shape, ] ``` ## Current HEAD ``` = ../test.rb:30:line: = ../test.rb:30:c_call:new = ../test.rb:30:c_call:inherited = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:const_added = ../test.rb:31:line: = ../test.rb:31:c_call:new = ../test.rb:31:c_call:initialize = ../test.rb:34:line: ``` ## Proposed PR ``` = ../test.rb:30:line: = ../test.rb:30:c_call:new = ../test.rb:30:c_call:inherited = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:singleton_method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:method_added = ../test.rb:30:c_call:const_added = ../test.rb:31:line: = ../test.rb:31:c_call:new = ../test.rb:31:c_call:initialize = ../test.rb:34:line: = ../test.rb:34:c_call:name = ../test.rb:35:c_call:shape ``` The reason is the internal implementation of struct doesn't have trace point instrumentation in `vm_call_opt_struct_aset` or `vm_call_opt_struct_aref`. Proposed fix: https://github.com/ruby/ruby/pull/6071 but this would need a review, maybe @jeremyevans0 and @ko1 can help.