Support 'restart call frame' debug command

test/mjsunit/debug-liveedit-restart-frame.js

+// Copyright 2012 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 FindCallFrame(exec_state, frame_code) {
+  var number = Number(frame_code);
+  if (number >= 0) {
+    return exec_state.frame(number);
+  } else {
+    for (var i = 0; i < exec_state.frameCount(); i++) {
+      var frame = exec_state.frame(i);
+      var func_mirror = frame.func();
+      if (frame_code == func_mirror.name()) {
+        return frame;
+      }
+    }
+  }
+  throw new Error("Failed to find function name " + function_name);
+}
+
+function TestCase(test_scenario, expected_output) {
+  // Global variable, accessed from eval'd script.
+  test_output = "";
+
+  function TestCode() {
+    function A() {
+      // Extra stack variable. To make function not slim.
+      // Restarter doesn't work on slim function when stopped on 'debugger'
+      // statement. (There is no padding for 'debugger' statement).
+      var o = {};
+      test_output += 'A';
+      test_output += '=';
+      debugger;
+      return 'Capybara';
+    }
+    function B(p1, p2) {
+      test_output += 'B';
+      return A();
+    }
+    function C() {
+      test_output += 'C';
+      // Function call with argument adaptor is intentional.
+      return B();
+    }
+    function D() {
+      test_output += 'D';
+      // Function call with argument adaptor is intentional.
+      return C(1, 2);
+    }
+    function E() {
+      test_output += 'E';
+      return D();
+    }
+    function F() {
+      test_output += 'F';
+      return E();
+    }
+    return F();
+  }
+
+  var scenario_pos = 0;
+
+  function DebuggerStatementHandler(exec_state) {
+    while (true) {
+      assertTrue(scenario_pos < test_scenario.length);
+      var change_code = test_scenario[scenario_pos++];
+      if (change_code == '=') {
+        // Continue.
+        return;
+      }
+      var frame = FindCallFrame(exec_state, change_code);
+      // Throws if fails.
+      Debug.LiveEdit.RestartFrame(frame);
+    }
+  }
+
+  var saved_exception = null;
+
+  function listener(event, exec_state, event_data, data) {
+    if (saved_exception != null) {
+      return;
+    }
+    if (event == Debug.DebugEvent.Break) {
+      try {
+        DebuggerStatementHandler(exec_state);
+      } catch (e) {
+        saved_exception = e;
+      }
+    } else {
+      print("Other: " + event);
+    }
+  }
+
+  Debug.setListener(listener);
+  assertEquals("Capybara", TestCode());
+  Debug.setListener(null);
+
+  if (saved_exception) {
+    print("Exception: " + saved_exception);
+    print("Stack: " + saved_exception.stack);
+    assertUnreachable();
+  }
+
+  print(test_output);
+
+  assertEquals(expected_output, test_output);
+}
+
+TestCase('0==', "FEDCBA=A=");
+TestCase('1==', "FEDCBA=BA=");
+TestCase('2==', "FEDCBA=CBA=");
+TestCase('3==', "FEDCBA=DCBA=");
+TestCase('4==', "FEDCBA=EDCBA=");
+TestCase('5==', "FEDCBA=FEDCBA=");
+
+TestCase('=', "FEDCBA=");
+
+TestCase('C==', "FEDCBA=CBA=");
+
+TestCase('B=C=A=D==', "FEDCBA=BA=CBA=A=DCBA=");
+
+// Successive restarts don't work now and require additional fix.
+//TestCase('BCDE==', "FEDCBA=EDCBA=");
+//TestCase('BC=BCDE==', "FEDCBA=CBA=EDCBA=");
+//TestCase('EF==', "FEDCBA=FEDCBA=");