Simplify calling generated code from the runtime.

src/execution.cc

 // 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 48 matching lines @@
 
 
 void StackGuard::reset_limits(const ExecutionAccess& lock) {
   ASSERT(isolate_ != NULL);
   thread_local_.jslimit_ = thread_local_.real_jslimit_;
   thread_local_.climit_ = thread_local_.real_climit_;
   isolate_->heap()->SetStackLimits();
 }
 
 
-static Handle<Object> Invoke(bool construct,
-                             Handle<JSFunction> func,
+static Handle<Object> Invoke(bool is_construct,
+                             Handle<JSFunction> function,
                              Handle<Object> receiver,
                              int argc,
-                             Object*** args,
+                             Handle<Object> args[],
                              bool* has_pending_exception) {
-  Isolate* isolate = func->GetIsolate();
+  Isolate* isolate = function->GetIsolate();
 
   // Entering JavaScript.
   VMState state(isolate, JS);
 
   // Placeholder for return value.
   MaybeObject* value = reinterpret_cast<Object*>(kZapValue);
 
-  typedef Object* (*JSEntryFunction)(
-    byte* entry,
-    Object* function,
-    Object* receiver,
-    int argc,
-    Object*** args);
+  typedef Object* (*JSEntryFunction)(byte* entry,
+                                     Object* function,
+                                     Object* receiver,
+                                     int argc,
+                                     Object*** args);
 
-  Handle<Code> code;
-  if (construct) {
-    code = isolate->factory()->js_construct_entry_code();
-  } else {
-    code = isolate->factory()->js_entry_code();
-  }
+  Handle<Code> code = is_construct
+      ? isolate->factory()->js_construct_entry_code()
+      : isolate->factory()->js_entry_code();
 
   // Convert calls on global objects to be calls on the global
   // receiver instead to avoid having a 'this' pointer which refers
   // directly to a global object.
   if (receiver->IsGlobalObject()) {
     Handle<GlobalObject> global = Handle<GlobalObject>::cast(receiver);
     receiver = Handle<JSObject>(global->global_receiver());
   }
 
   // Make sure that the global object of the context we're about to
   // make the current one is indeed a global object.
-  ASSERT(func->context()->global()->IsGlobalObject());
+  ASSERT(function->context()->global()->IsGlobalObject());
 
   {
     // Save and restore context around invocation and block the
     // allocation of handles without explicit handle scopes.
     SaveContext save(isolate);
     NoHandleAllocation na;
-    JSEntryFunction entry = FUNCTION_CAST<JSEntryFunction>(code->entry());
+    JSEntryFunction stub_entry = FUNCTION_CAST<JSEntryFunction>(code->entry());
 
     // Call the function through the right JS entry stub.
-    byte* entry_address = func->code()->entry();
-    JSFunction* function = *func;
-    Object* receiver_pointer = *receiver;
-    value = CALL_GENERATED_CODE(entry, entry_address, function,
-                                receiver_pointer, argc, args);
+    byte* function_entry = function->code()->entry();
+    JSFunction* func = *function;
+    Object* recv = *receiver;
+    Object*** argv = reinterpret_cast<Object***>(args);
+    value =
+        CALL_GENERATED_CODE(stub_entry, function_entry, func, recv, argc, argv);
   }
 
 #ifdef DEBUG
   value->Verify();
 #endif
 
   // Update the pending exception flag and return the value.
   *has_pending_exception = value->IsException();
   ASSERT(*has_pending_exception == Isolate::Current()->has_pending_exception());
   if (*has_pending_exception) {
     isolate->ReportPendingMessages();
     if (isolate->pending_exception() == Failure::OutOfMemoryException()) {
       if (!isolate->ignore_out_of_memory()) {
         V8::FatalProcessOutOfMemory("JS", true);
       }
     }
     return Handle<Object>();
   } else {
     isolate->clear_pending_message();
   }
 
   return Handle<Object>(value->ToObjectUnchecked(), isolate);
 }
 
 
 Handle<Object> Execution::Call(Handle<Object> callable,
                                Handle<Object> receiver,
                                int argc,
-                               Object*** args,
+                               Handle<Object> argv[],
                                bool* pending_exception,
                                bool convert_receiver) {
   *pending_exception = false;
 
   if (!callable->IsJSFunction()) {
     callable = TryGetFunctionDelegate(callable, pending_exception);
     if (*pending_exception) return callable;
   }
   Handle<JSFunction> func = Handle<JSFunction>::cast(callable);
 
   // In non-strict mode, convert receiver.
   if (convert_receiver && !receiver->IsJSReceiver() &&
       !func->shared()->native() && !func->shared()->strict_mode()) {
     if (receiver->IsUndefined() || receiver->IsNull()) {
       Object* global = func->context()->global()->global_receiver();
       // Under some circumstances, 'global' can be the JSBuiltinsObject
       // In that case, don't rewrite.
       // (FWIW, the same holds for GetIsolate()->global()->global_receiver().)
       if (!global->IsJSBuiltinsObject()) receiver = Handle<Object>(global);
     } else {
       receiver = ToObject(receiver, pending_exception);
     }
     if (*pending_exception) return callable;
   }
 
-  return Invoke(false, func, receiver, argc, args, pending_exception);
+  return Invoke(false, func, receiver, argc, argv, pending_exception);
 }
 
 
-Handle<Object> Execution::New(Handle<JSFunction> func, int argc,
-                              Object*** args, bool* pending_exception) {
-  return Invoke(true, func, Isolate::Current()->global(), argc, args,
+Handle<Object> Execution::New(Handle<JSFunction> func,
+                              int argc,
+                              Handle<Object> argv[],
+                              bool* pending_exception) {
+  return Invoke(true, func, Isolate::Current()->global(), argc, argv,
                 pending_exception);
 }
 
 
 Handle<Object> Execution::TryCall(Handle<JSFunction> func,
                                   Handle<Object> receiver,
                                   int argc,
-                                  Object*** args,
+                                  Handle<Object> args[],
                                   bool* caught_exception) {
   // Enter a try-block while executing the JavaScript code. To avoid
   // duplicate error printing it must be non-verbose.  Also, to avoid
   // creating message objects during stack overflow we shouldn't
   // capture messages.
   v8::TryCatch catcher;
   catcher.SetVerbose(false);
   catcher.SetCaptureMessage(false);
   *caught_exception = false;
 
@@ skipping 365 matching lines @@
   uintptr_t stored_limit = per_thread->stack_limit();
   // You should hold the ExecutionAccess lock when you call this.
   if (stored_limit != 0) {
     SetStackLimit(stored_limit);
   }
 }
 
 
 // --- C a l l s   t o   n a t i v e s ---
 
-#define RETURN_NATIVE_CALL(name, argc, argv, has_pending_exception)            \
-  do {                                                                         \
-    Isolate* isolate = Isolate::Current();                                     \
-    Object** args[argc] = argv;                                                \
-    ASSERT(has_pending_exception != NULL);                                     \
-    return Call(isolate->name##_fun(),                                         \
-                isolate->js_builtins_object(), argc, args,                     \
-                has_pending_exception);                                        \
+#define RETURN_NATIVE_CALL(name, args, has_pending_exception)           \
+  do {                                                                  \
+    Isolate* isolate = Isolate::Current();                              \
+    Handle<Object> argv[] = args;                                       \
+    ASSERT(has_pending_exception != NULL);                              \
+    return Call(isolate->name##_fun(),                                  \
+                isolate->js_builtins_object(),                          \
+                ARRAY_SIZE(argv), argv,                                 \

[rossberg, 2011/10/05 13:10:17]

I guess it doesn't matter much, because the macro is only used locally, but
isn't this a bit dangerous? Does it give a compile time error if somebody tries
to invoke the macro with args not being a static array?

[Kevin Millikin (Chromium), 2011/10/05 13:47:26]

Yeah, it's a bit dangerous and the programmer has to be careful.

It was also a bit dangerous to have the named constants and magic numbers that
had to agree with the arg count before, though.

+                has_pending_exception);                                 \
   } while (false)
 
 
 Handle<Object> Execution::ToBoolean(Handle<Object> obj) {
   // See the similar code in runtime.js:ToBoolean.
   if (obj->IsBoolean()) return obj;
   bool result = true;
   if (obj->IsString()) {
     result = Handle<String>::cast(obj)->length() != 0;
   } else if (obj->IsNull() || obj->IsUndefined()) {
     result = false;
   } else if (obj->IsNumber()) {
     double value = obj->Number();
     result = !((value == 0) || isnan(value));
   }
   return Handle<Object>(HEAP->ToBoolean(result));
 }
 
 
 Handle<Object> Execution::ToNumber(Handle<Object> obj, bool* exc) {
-  RETURN_NATIVE_CALL(to_number, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_number, { obj }, exc);
 }
 
 
 Handle<Object> Execution::ToString(Handle<Object> obj, bool* exc) {
-  RETURN_NATIVE_CALL(to_string, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_string, { obj }, exc);
 }
 
 
 Handle<Object> Execution::ToDetailString(Handle<Object> obj, bool* exc) {
-  RETURN_NATIVE_CALL(to_detail_string, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_detail_string, { obj }, exc);
 }
 
 
 Handle<Object> Execution::ToObject(Handle<Object> obj, bool* exc) {
   if (obj->IsSpecObject()) return obj;
-  RETURN_NATIVE_CALL(to_object, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_object, { obj }, exc);
 }
 
 
 Handle<Object> Execution::ToInteger(Handle<Object> obj, bool* exc) {
-  RETURN_NATIVE_CALL(to_integer, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_integer, { obj }, exc);
 }
 
 
 Handle<Object> Execution::ToUint32(Handle<Object> obj, bool* exc) {
-  RETURN_NATIVE_CALL(to_uint32, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_uint32, { obj }, exc);
 }
 
 
 Handle<Object> Execution::ToInt32(Handle<Object> obj, bool* exc) {
-  RETURN_NATIVE_CALL(to_int32, 1, { obj.location() }, exc);
+  RETURN_NATIVE_CALL(to_int32, { obj }, exc);
 }
 
 
 Handle<Object> Execution::NewDate(double time, bool* exc) {
   Handle<Object> time_obj = FACTORY->NewNumber(time);
-  RETURN_NATIVE_CALL(create_date, 1, { time_obj.location() }, exc);
+  RETURN_NATIVE_CALL(create_date, { time_obj }, exc);
 }
 
 
 #undef RETURN_NATIVE_CALL
 
 
 Handle<JSRegExp> Execution::NewJSRegExp(Handle<String> pattern,
                                         Handle<String> flags,
                                         bool* exc) {
   Handle<JSFunction> function = Handle<JSFunction>(
@@ skipping 16 matching lines @@
 
   Handle<Object> char_at =
       GetProperty(isolate->js_builtins_object(),
                   factory->char_at_symbol());
   if (!char_at->IsJSFunction()) {
     return factory->undefined_value();
   }
 
   bool caught_exception;
   Handle<Object> index_object = factory->NewNumberFromInt(int_index);
-  Object** index_arg[] = { index_object.location() };
+  Handle<Object> index_arg[] = { index_object };
   Handle<Object> result = TryCall(Handle<JSFunction>::cast(char_at),
                                   string,
                                   ARRAY_SIZE(index_arg),
                                   index_arg,
                                   &caught_exception);
   if (caught_exception) {
     return factory->undefined_value();
   }
   return result;
 }
 
 
 Handle<JSFunction> Execution::InstantiateFunction(
-    Handle<FunctionTemplateInfo> data, bool* exc) {
+    Handle<FunctionTemplateInfo> data,
+    bool* exc) {
   Isolate* isolate = data->GetIsolate();
   // Fast case: see if the function has already been instantiated
   int serial_number = Smi::cast(data->serial_number())->value();
   Object* elm =
       isolate->global_context()->function_cache()->
           GetElementNoExceptionThrown(serial_number);
   if (elm->IsJSFunction()) return Handle<JSFunction>(JSFunction::cast(elm));
   // The function has not yet been instantiated in this context; do it.
-  Object** args[1] = { Handle<Object>::cast(data).location() };
-  Handle<Object> result =
-      Call(isolate->instantiate_fun(),
-           isolate->js_builtins_object(), 1, args, exc);
+  Handle<Object> args[] = { data };
+  Handle<Object> result = Call(isolate->instantiate_fun(),
+                               isolate->js_builtins_object(),
+                               ARRAY_SIZE(args),
+                               args,
+                               exc);
   if (*exc) return Handle<JSFunction>::null();
   return Handle<JSFunction>::cast(result);
 }
 
 
 Handle<JSObject> Execution::InstantiateObject(Handle<ObjectTemplateInfo> data,
                                               bool* exc) {
   Isolate* isolate = data->GetIsolate();
   if (data->property_list()->IsUndefined() &&
       !data->constructor()->IsUndefined()) {
     // Initialization to make gcc happy.
     Object* result = NULL;
     {
       HandleScope scope(isolate);
       Handle<FunctionTemplateInfo> cons_template =
           Handle<FunctionTemplateInfo>(
               FunctionTemplateInfo::cast(data->constructor()));
       Handle<JSFunction> cons = InstantiateFunction(cons_template, exc);
       if (*exc) return Handle<JSObject>::null();
       Handle<Object> value = New(cons, 0, NULL, exc);
       if (*exc) return Handle<JSObject>::null();
       result = *value;
     }
     ASSERT(!*exc);
     return Handle<JSObject>(JSObject::cast(result));
   } else {
-    Object** args[1] = { Handle<Object>::cast(data).location() };
-    Handle<Object> result =
-        Call(isolate->instantiate_fun(),
-             isolate->js_builtins_object(), 1, args, exc);
+    Handle<Object> args[] = { data };
+    Handle<Object> result = Call(isolate->instantiate_fun(),
+                                 isolate->js_builtins_object(),
+                                 ARRAY_SIZE(args),
+                                 args,
+                                 exc);
     if (*exc) return Handle<JSObject>::null();
     return Handle<JSObject>::cast(result);
   }
 }
 
 
 void Execution::ConfigureInstance(Handle<Object> instance,
                                   Handle<Object> instance_template,
                                   bool* exc) {
   Isolate* isolate = Isolate::Current();
-  Object** args[2] = { instance.location(), instance_template.location() };
+  Handle<Object> args[] = { instance, instance_template };
   Execution::Call(isolate->configure_instance_fun(),
-                  isolate->js_builtins_object(), 2, args, exc);
+                  isolate->js_builtins_object(),
+                  ARRAY_SIZE(args),
+                  args,
+                  exc);
 }
 
 
 Handle<String> Execution::GetStackTraceLine(Handle<Object> recv,
                                             Handle<JSFunction> fun,
                                             Handle<Object> pos,
                                             Handle<Object> is_global) {
   Isolate* isolate = fun->GetIsolate();
-  const int argc = 4;
-  Object** args[argc] = { recv.location(),
-                          Handle<Object>::cast(fun).location(),
-                          pos.location(),
-                          is_global.location() };
+  Handle<Object> args[] = { recv, fun, pos, is_global };
   bool caught_exception;
-  Handle<Object> result =
-      TryCall(isolate->get_stack_trace_line_fun(),
-              isolate->js_builtins_object(), argc, args,
-              &caught_exception);
+  Handle<Object> result = TryCall(isolate->get_stack_trace_line_fun(),
+                                  isolate->js_builtins_object(),
+                                  ARRAY_SIZE(args),
+                                  args,
+                                  &caught_exception);
   if (caught_exception || !result->IsString()) {
       return isolate->factory()->empty_symbol();
   }
 
   return Handle<String>::cast(result);
 }
 
 
 static Object* RuntimePreempt() {
   Isolate* isolate = Isolate::Current();
@@ skipping 117 matching lines @@
     return isolate->TerminateExecution();
   }
   if (stack_guard->IsInterrupted()) {
     stack_guard->Continue(INTERRUPT);
     return isolate->StackOverflow();
   }
   return isolate->heap()->undefined_value();
 }
 
 } }  // namespace v8::internal