Better handling of stepping out of a function...

test/mjsunit/debug-return-value.js

+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --expose-debug-as debug
+// Get the Debug object exposed from the debug context global object.
+Debug = debug.Debug
+
+
+function ParsedResponse(json) {
+  this.response_ = eval('(' + json + ')');
+  this.refs_ = [];
+  if (this.response_.refs) {
+    for (var i = 0; i < this.response_.refs.length; i++) {
+      this.refs_[this.response_.refs[i].handle] = this.response_.refs[i];
+    }
+  }
+}
+
+
+ParsedResponse.prototype.response = function() {
+  return this.response_;
+}
+
+
+ParsedResponse.prototype.body = function() {
+  return this.response_.body;
+}
+
+
+ParsedResponse.prototype.running = function() {
+  return this.response_.running;
+}
+
+
+ParsedResponse.prototype.lookup = function(handle) {
+  return this.refs_[handle];
+}
+
+
+listener_complete = false;
+exception = false;
+break_count = 0;
+expected_return_value = 0;
+debugger_source_position = 0;
+
+// Listener which expects to do four steps to reach returning from the function.
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Break)
+    {
+      break_count++;
+      if (break_count < 4) {
+        assertFalse(exec_state.frame(0).isAtReturn())
+        switch (break_count) {
+          case 1:
+            // Collect the position of the debugger statement.
+            debugger_source_position = exec_state.frame(0).sourcePosition();
+            break;
+          case 2:
+            // Position now at the if statement.
+            assertEquals(debugger_source_position + 10,
+                         exec_state.frame(0).sourcePosition());
+            break;
+          case 3:
+            // Position now at either of the returns.
+            if (expected_return_value == 1) {
+              assertEquals(debugger_source_position + 19,
+                           exec_state.frame(0).sourcePosition());
+            } else {
+              assertEquals(debugger_source_position + 38,
+                           exec_state.frame(0).sourcePosition());
+            }
+            break;
+          default:
+            fail("Unexpected");
+        }
+        exec_state.prepareStep(Debug.StepAction.StepIn, 1);
+      } else {
+        // Position at the end of the function.
+        assertEquals(debugger_source_position + 51,
+        exec_state.frame(0).sourcePosition());
+        
+        // Just about to return from the function.
+        assertTrue(exec_state.frame(0).isAtReturn())
+        assertEquals(expected_return_value,
+                     exec_state.frame(0).returnValue().value());
+        
+        // Check the same using the JSON commands.
+        var dcp = exec_state.debugCommandProcessor(false);
+        var request = '{"seq":0,"type":"request","command":"backtrace"}';
+        var resp = dcp.processDebugJSONRequest(request);
+        response = new ParsedResponse(resp);
+        frames = response.body().frames;
+        assertTrue(frames[0].atReturn);
+        assertEquals(expected_return_value,
+                     response.lookup(frames[0].returnValue.ref).value);
+        
+        listener_complete = true;
+      }
+    }
+  } catch (e) {
+    exception = e
+  };
+};
+
+// Add the debug event listener.
+Debug.setListener(listener);
+
+// Four steps from the debugger statement in this function will position us at
+// the function return.
+//             0         1         2         3         4         5 
+//             0123456789012345678901234567890123456789012345678901
+
+function f(x) {debugger; if (x) { return 1; } else { return 2; } };
+
+// Call f expecting different return values.
+break_count = 0;
+expected_return_value = 2;
+listener_complete = false;
+f();
+assertFalse(exception, "exception in listener")
+assertTrue(listener_complete);
+assertEquals(4, break_count);
+
+break_count = 0;
+expected_return_value = 1;
+listener_complete = false;
+f(true);
+assertFalse(exception, "exception in listener")
+assertTrue(listener_complete);
+assertEquals(4, break_count);
+
+break_count = 0;
+expected_return_value = 2;
+listener_complete = false;
+f(false);
+assertFalse(exception, "exception in listener")
+assertTrue(listener_complete);
+assertEquals(4, break_count);