Handle symbols in FrameMirror#invocationText().

test/mjsunit/debug-backtrace-text.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 40 matching lines @@
 
 function createPoint(x, y) {
   return new Point(x, y);
 }
 
 a=[1,2,distance];
 
 // Get the Debug object exposed from the debug context global object.
 Debug = debug.Debug
 
-testConstructor = false;  // Flag to control which part of the test is run.
+what = 'constructor';  // Flag to control which part of the test is run.
 listenerCalled = false;
 exception = false;
 
 function safeEval(code) {
   try {
     return eval('(' + code + ')');
   } catch (e) {
     return undefined;
   }
 }
 
 function listener(event, exec_state, event_data, data) {
   try {
-  if (event == Debug.DebugEvent.Break)
-  {
-    if (!testConstructor) {
-      // The expected backtrace is
-      // 0: Call distance on Point where distance is a property on the prototype
-      // 1: Call distance on Point where distance is a direct property
-      // 2: Call on function an array element 2
-      // 3: [anonymous]
-      assertEquals("#<Point>.distanceTo(p=#<Point>)", exec_state.frame(0).invocationText());
-      assertEquals("#<Point>.distanceTo(p=#<Point>)", exec_state.frame(1).invocationText());
-      assertEquals("#<Array>[2](aka distance)(p=#<Point>, q=#<Point>)", exec_state.frame(2).invocationText());
-      assertEquals("[anonymous]()", exec_state.frame(3).invocationText());
-      listenerCalled = true;
-    } else {
-      // The expected backtrace is
-      // 0: Call Point constructor
-      // 1: Call on global function createPoint
-      // 2: [anonymous]
-      assertEquals("new Point(x=0, y=0)", exec_state.frame(0).invocationText());
-      assertEquals("createPoint(x=0, y=0)", exec_state.frame(1).invocationText());
-      assertEquals("[anonymous]()", exec_state.frame(2).invocationText());
-      listenerCalled = true;
+    if (event == Debug.DebugEvent.Break) {
+      if (what == 'constructor') {
+        // The expected backtrace is
+        // 0: Call distance on Point where distance is a property on the prototype

[Yang, 2016/07/06 05:39:29]

Since you already did the work below, how about also keep the 80-char limit
here.

+        // 1: Call distance on Point where distance is a direct property
+        // 2: Call on function an array element 2
+        // 3: [anonymous]
+        assertEquals("#<Point>.distanceTo(p=#<Point>)",
+                     exec_state.frame(0).invocationText());
+        assertEquals("#<Point>.distanceTo(p=#<Point>)",
+                     exec_state.frame(1).invocationText());
+        assertEquals("#<Array>[2](aka distance)(p=#<Point>, q=#<Point>)",
+                     exec_state.frame(2).invocationText());
+        assertEquals("[anonymous]()", exec_state.frame(3).invocationText());
+        listenerCalled = true;
+      } else if (what == 'breakpoint') {
+        // The expected backtrace is
+        // 0: Call Point constructor
+        // 1: Call on global function createPoint
+        // 2: [anonymous]
+        assertEquals("new Point(x=0, y=0)",
+                     exec_state.frame(0).invocationText());
+        assertEquals("createPoint(x=0, y=0)",
+                     exec_state.frame(1).invocationText());
+        assertEquals("[anonymous]()", exec_state.frame(2).invocationText());
+        listenerCalled = true;
+      } else if (what == 'symbol') {
+        // The expected backtrace is
+        // 0: Call Point constructor
+        // 1: Call on symbol method
+        // 2: [anonymous]
+        assertEquals("new Point(x=0, y=0)",
+                     exec_state.frame(0).invocationText());
+        assertEquals("#<Object>[Symbol(Das Symbol)](x=0, y=0)",
+                     exec_state.frame(1).invocationText());
+        assertEquals("[anonymous]()", exec_state.frame(2).invocationText());
+        listenerCalled = true;
+      } else {
+        assertUnreachable();
+      }
     }
-  }
   } catch (e) {
     exception = e
   };
 };
 
 // Add the debug event listener.
 Debug.setListener(listener);
 
 // Set a break point and call to invoke the debug event listener.
 a[2](p1, p2)
 
 // Make sure that the debug event listener vas invoked.
 assertTrue(listenerCalled);
 assertFalse(exception, "exception in listener")
 
 // Set a break point and call to invoke the debug event listener.
+what = 'breakpoint';
 listenerCalled = false;
-testConstructor = true;
 Debug.setBreakPoint(Point, 0, 0);
 createPoint(0, 0);
 
 // Make sure that the debug event listener vas invoked (again).
 assertTrue(listenerCalled);
 assertFalse(exception, "exception in listener")
+
+what = 'symbol';
+listenerCalled = false;
+var S = Symbol('Das Symbol');
+var o = { [S](x, y) { return new Point(x, y); } };
+Debug.setBreakPoint(Point, 0, 0);
+o[S](0, 0);
+
+assertTrue(listenerCalled);
+assertFalse(exception, "exception in listener")