Truffle/Tools: a new framework for pluggable tools that gather Truffle execution data - Abstract com.oracle.truffle.api.instrument.TruffleTool defines, documents, and enforces a standard "life cycle": -- includes creation, installation, enabling/disabling, and disposing. -- data retrieval is tool dependent, but each is encouraged to provide a default print() method for demo & debugging - com.oracle.truffle.api.tools contains three instances, all language-agnostic: -- LineToProbesMap: existing utility used by the debugger, adapted to the frameowrk -- CoverageTracker: code coverage, tabulated by line -- NodeExecCounter: raw execution counts, tabulated by node type, can be filtered by SyntaxTag