Devtools: expose scopes source location to debugger

test/mjsunit/debug-scopes.js

 // Copyright 2011 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 205 matching lines @@
   } else {
     assertTrue(response.body.object.ref >= 0);
   }
   var found = false;
   for (var i = 0; i < response.refs.length && !found; i++) {
     found = response.refs[i].handle == response.body.object.ref;
   }
   assertTrue(found, "Scope object " + response.body.object.ref + " not found");
 }
 
+// Check that the scopes have positions as expected.
+function CheckScopeChainPositions(positions, exec_state) {
+  var all_scopes = exec_state.frame().allScopes();
+  assertEquals(positions.length, all_scopes.length, "FrameMirror.allScopes length");
+  for (var i = 0; i < positions.length; i++) {
+    var scope = exec_state.frame().scope(i);
+    assertTrue(scope.isScope());
+    var position = positions[i];
+    if (!position)
+      continue;
+
+    assertEquals(position.start, scope.details().startPosition())
+    assertEquals(position.end, scope.details().endPosition())
+  }
+}
 
 // Simple empty local scope.
 BeginTest("Local 1");
 
 function local_1() {
   debugger;
 }
 
 listener_delegate = function(exec_state) {
   CheckScopeChain([debug.ScopeType.Local,
@@ skipping 866 matching lines @@
   class C1 {
     m() {
       debugger;
     }
   }
   new C1().m();
 })();
 
 EndTest();
 
+BeginTest("Scope positions");
+var code1 = "function f() {        \n" +
+            "  var a = 1;          \n" +
+            "  function b() {      \n" +
+            "    debugger;         \n" +
+            "    return a + 1;     \n" +
+            "  }                   \n" +
+            "  b();                \n" +
+            "}                     \n" +
+            "f();                  \n";
+
+listener_delegate = function(exec_state) {
+  CheckScopeChainPositions([{start: 58  , end: 118}, {start: 10, end: 162}, {}, {}], exec_state);

[Yang, 2016/02/25 21:25:17]

whitespace before comma is weird

[sergeyv, 2016/02/26 00:29:29]

Done.

+}
+eval(code1);
+EndTest();
+
+
+function catch_block_2() {
+  try {
+    throw 'Exception';
+  } catch (e) {
+    with({n:10}) {
+      debugger;
+    }
+  }
+};
+
+BeginTest("Scope positions in catch and 'with' statement");
+var code2 = "function catch_block() {   \n" +
+            "  try {                    \n" +
+            "    throw 'Exception';     \n" +
+            "  } catch (e) {            \n" +
+            "    with({n : 10}) {       \n" +
+            "      debugger;            \n" +
+            "    }                      \n" +
+            "  }                        \n" +
+            "}                          \n" +
+            "catch_block();             \n";
+
+listener_delegate = function(exec_state) {
+  CheckScopeChainPositions([{start: 131, end: 173}, {start: 94, end: 199}, {start: 20, end: 225}, {}, {}], exec_state);
+}
+eval(code2);
+EndTest();
+
+BeginTest("Scope positions in for statement");
+var code3 = "function for_statement() {         \n" +
+            "  for (let i = 0; i < 1; i++) {    \n" +
+            "    debugger;                      \n" +
+            "  }                                \n" +
+            "}                                  \n" +
+            "for_statement();                   \n";
+
+listener_delegate = function(exec_state) {
+  CheckScopeChainPositions([{start: 52, end: 111}, {start: 42, end: 111}, {start: 22, end: 145}, {}, {}], exec_state);

[sergeyv, 2016/02/25 20:45:55]

I don't quite get why do we have 5 scopes instead of 4.
Btw, start position for the scope at 0-position looks quite strange. Does it
work as intended?

[Yang, 2016/02/25 21:25:17]

not sure. can you also add scope type to the check and expectation? might be
block scope for the let-variable inside the for-loop.

[sergeyv, 2016/02/26 00:29:29]

Added scope type. We have two block-statement here, from Devtools point of view
it looks strange: there are two scopes in both of them i is defined and have the
same value.

+}
+eval(code3);
+EndTest();
 
 assertEquals(begin_test_count, break_count,
              'one or more tests did not enter the debugger');
 assertEquals(begin_test_count, end_test_count,
              'one or more tests did not have its result checked');