From: "headius (Charles Nutter)" Date: 2012-12-10T11:17:06+09:00 Subject: [ruby-core:50724] [ruby-trunk - Feature #7436] Allow for a "granularity" flag for backtrace_locations Issue #7436 has been updated by headius (Charles Nutter). As a debugging feature I can support access to arbitrary. As a general, runtime, hot-path feature, there's numerous reasons why it's a terrible idea: * It exposes all method-local state to *everyone*. Any library anywhere can not only access your local variables but modify them too. A potentially massive security hole. * It requires that all method bodies everywhere in the system maintain all frame/scope state regardless of whether it's used or not, since "Binding.of_caller" style features could access it at any time. * It drastically limits optimization potential for Ruby. On a good day, JRuby can be 10x or more faster than MRI largely because we've been able to eliminate framing/scoping overhead. A Binding.of_caller feature would severely damage our performance and very likely limit forever general Ruby performance. ---------------------------------------- Feature #7436: Allow for a "granularity" flag for backtrace_locations https://bugs.ruby-lang.org/issues/7436#change-34574 Author: sam.saffron (Sam Saffron) Status: Assigned Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor related to http://bugs.ruby-lang.org/issues/7051 Sometimes one need less information (or more information) associated with backtraces. It would be nice if one could send in a separate flag informing the VM about the granularity of information required, eg: caller_locations(0,-current_depth, BacktraceInfo::Label & BacktraceInfo::Lineno) This allows for one to take quicker backtraces if they need less information, additionally BacktraceInfo::Bindings and BacktraceInfo::Klass could be added which allow you to gather more information for heavy profiling / diagnostics. -- http://bugs.ruby-lang.org/