add optional tracing of REngine.makeCallTarget

com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/REngine.java

@@ -33,6 +33,7 @@ import com.oracle.truffle.api.frame.*;
 import com.oracle.truffle.api.nodes.*;
 import com.oracle.truffle.api.source.*;
 import com.oracle.truffle.r.nodes.*;
+import com.oracle.truffle.r.nodes.access.*;
 import com.oracle.truffle.r.nodes.builtin.*;
 import com.oracle.truffle.r.nodes.function.*;
 import com.oracle.truffle.r.options.*;
@@ -335,6 +336,8 @@ public final class REngine implements RContext.Engine {
         return result;
     }
 
+    private static boolean traceMakeCallTarget;
+
     /**
      * Wraps the Truffle AST in {@code node} in an anonymous function and returns a
      * {@link RootCallTarget} for it. We define the
@@ -350,12 +353,33 @@ public final class REngine implements RContext.Engine {
      */
     @SlowPath
     private static RootCallTarget makeCallTarget(RNode body) {
+        if (traceMakeCallTarget) {
+            doTraceMakeCallTarget(body);
+        }
         REnvironment.FunctionDefinition rootNodeEnvironment = new REnvironment.FunctionDefinition(REnvironment.emptyEnv());
         FunctionDefinitionNode rootNode = new FunctionDefinitionNode(null, rootNodeEnvironment, body, FormalArguments.NO_ARGS, "<wrapper>", true);
         RootCallTarget callTarget = Truffle.getRuntime().createCallTarget(rootNode);
         return callTarget;
     }
 
+    private static void doTraceMakeCallTarget(RNode body) {
+        String nodeClassName = body.getClass().getSimpleName();
+        SourceSection ss = body.getSourceSection();
+        String trace;
+        if (ss == null) {
+            System.console();
+            if (body instanceof ConstantNode) {
+                trace = ((ConstantNode) body).getValue().toString();
+            } else {
+                trace = "not constant/no source";
+            }
+        } else {
+            trace = ss.toString();
+        }
+        RContext.getInstance().getConsoleHandler().printf("makeCallTarget: node: %s, %s%n", nodeClassName, trace);
+
+    }
+
     /**
      * Execute {@code callTarget} in {@code frame}, optionally printing any result. N.B.
      * {@code callTarget.call} will create a new {@link VirtualFrame} called, say, {@code newFrame},