Fix an issue with debugger 'step in' when calling function has local...

Fix an issue with debugger 'step in' when calling function has local variables.Corresponding Chromium bug:http://code.google.com/p/chromium/issues/detail?id=15824
Review URL: http://codereview.chromium.org/149326

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2426 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/debug.cc

@@ -1260,6 +1260,7 @@ void Debug::SetBreak(StackFrame::Id break_frame_id, int break_id) {
 
 // Handle stepping into a function.
 void Debug::HandleStepIn(Handle<JSFunction> function,
+                         Handle<Object> holder,
                          Address fp,
                          bool is_constructor) {
   // If the frame pointer is not supplied by the caller find it.
@@ -1285,21 +1286,12 @@ void Debug::HandleStepIn(Handle<JSFunction> function,
           Builtins::builtin(Builtins::FunctionCall)) {
         // Handle function.apply and function.call separately to flood the
         // function to be called and not the code for Builtins::FunctionApply or
-        // Builtins::FunctionCall. At the point of the call IC to call either
-        // Builtins::FunctionApply or Builtins::FunctionCall the expression
-        // stack has the following content:
-        //   symbol "apply" or "call"
-        //   function apply or call was called on
-        //   receiver for apply or call (first parameter to apply or call)
-        //   ... further arguments to apply or call.
-        JavaScriptFrameIterator it;
-        ASSERT(it.frame()->fp() == fp);
-        ASSERT(it.frame()->GetExpression(1)->IsJSFunction());
-        if (it.frame()->GetExpression(1)->IsJSFunction()) {
-          Handle<JSFunction>
-              actual_function(JSFunction::cast(it.frame()->GetExpression(1)));
-          Handle<SharedFunctionInfo> actual_shared(actual_function->shared());
-          Debug::FloodWithOneShot(actual_shared);
+        // Builtins::FunctionCall. The receiver of call/apply is the target
+        // function.
+        if (!holder.is_null() && holder->IsJSFunction()) {
+          Handle<SharedFunctionInfo> shared_info(
+              JSFunction::cast(*holder)->shared());
+          Debug::FloodWithOneShot(shared_info);
         }
       } else {
         Debug::FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared()));

src/debug.h

@@ -270,6 +270,7 @@ class Debug {
 
   static bool StepInActive() { return thread_local_.step_into_fp_ != 0; }
   static void HandleStepIn(Handle<JSFunction> function,
+                           Handle<Object> holder,
                            Address fp,
                            bool is_constructor);
   static Address step_in_fp() { return thread_local_.step_into_fp_; }

src/ic.cc

@@ -397,7 +397,7 @@ Object* CallIC::LoadFunction(State state,
       // cause GC.
       HandleScope scope;
       Handle<JSFunction> function(JSFunction::cast(result));
-      Debug::HandleStepIn(function, fp(), false);
+      Debug::HandleStepIn(function, object, fp(), false);
       return *function;
     }
 #endif

src/runtime.cc

@@ -4316,7 +4316,7 @@ static Object* Runtime_NewObject(Arguments args) {
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Handle stepping into constructors if step into is active.
   if (Debug::StepInActive()) {
-    Debug::HandleStepIn(function, 0, true);
+    Debug::HandleStepIn(function, Handle<Object>::null(), 0, true);
   }
 #endif
 

test/mjsunit/debug-stepin-function-call.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
+//       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
+
+var exception = null;
+var state = 0;
+
+// Simple debug event handler which first time will cause 'step in' action
+// to get into g.call and than check that execution is pauesed inside
+// function 'g'.
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Break) {
+      if (state == 0) {
+        // Step into f2.call:
+        exec_state.prepareStep(Debug.StepAction.StepIn, 2);
+        state = 2;
+      } else if (state == 2) {
+        assertEquals('g', event_data.func().name());
+        assertEquals('  return t + 1; // expected line',
+                     event_data.sourceLineText());
+        state = 3;
+      }
+    }
+  } catch(e) {
+    exception = e;
+  }
+};
+
+// Add the debug event listener.
+Debug.setListener(listener);
+
+
+// Sample functions.
+function g(t) {
+  return t + 1; // expected line
+}
+
+// Test step into function call from a function without local variables.
+function call1() {
+  debugger;
+  g.call(null, 3);
+}
+
+
+// Test step into function call from a function with some local variables.
+function call2() {
+  var aLocalVar = 'test';
+  var anotherLocalVar  = g(aLocalVar) + 's';
+  var yetAnotherLocal = 10;
+  debugger;
+  g.call(null, 3);
+}
+
+// Test step into function call which is a part of an expression.
+function call3() {
+  var alias = g;
+  debugger;
+  var r = 10 + alias.call(null, 3);
+  var aLocalVar = 'test';
+  var anotherLocalVar  = g(aLocalVar) + 's';
+  var yetAnotherLocal = 10;
+}
+
+// Test step into function call from a function with some local variables.
+function call4() {
+  var alias = g;
+  debugger;
+  alias.call(null, 3);
+  var aLocalVar = 'test';
+  var anotherLocalVar  = g(aLocalVar) + 's';
+  var yetAnotherLocal = 10;
+}
+
+// Test step into function apply from a function without local variables.
+function apply1() {
+  debugger;
+  g.apply(null, [3]);
+}
+
+
+// Test step into function apply from a function with some local variables.
+function apply2() {
+  var aLocalVar = 'test';
+  var anotherLocalVar  = g(aLocalVar) + 's';
+  var yetAnotherLocal = 10;
+  debugger;
+  g.apply(null, [3, 4]);
+}
+
+// Test step into function apply which is a part of an expression.
+function apply3() {
+  var alias = g;
+  debugger;
+  var r = 10 + alias.apply(null, [3, 'unused arg']);
+  var aLocalVar = 'test';
+  var anotherLocalVar  = g(aLocalVar) + 's';
+  var yetAnotherLocal = 10;
+}
+
+// Test step into function apply from a function with some local variables.
+function apply4() {
+  var alias = g;
+  debugger;
+  alias.apply(null, [3]);
+  var aLocalVar = 'test';
+  var anotherLocalVar  = g(aLocalVar) + 's';
+  var yetAnotherLocal = 10;
+}
+
+var testFunctions =
+    [call1, call2, call3, call4, apply1, apply2, apply3, apply4];
+
+for (var i = 0; i < testFunctions.length; i++) {
+  state = 0;
+  testFunctions[i]();
+  assertNull(exception);
+  assertEquals(3, state);
+}
+
+// Get rid of the debug event listener.
+Debug.setListener(null);
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