1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #ifndef V8_ARGUMENTS_H_
29 #define V8_ARGUMENTS_H_
31 #include "allocation.h"
36 // Arguments provides access to runtime call parameters.
38 // It uses the fact that the instance fields of Arguments
39 // (length_, arguments_) are "overlayed" with the parameters
40 // (no. of parameters, and the parameter pointer) passed so
41 // that inside the C++ function, the parameters passed can
42 // be accessed conveniently:
44 // Object* Runtime_function(Arguments args) {
45 // ... use args[i] here ...
48 class Arguments BASE_EMBEDDED {
50 Arguments(int length, Object** arguments)
51 : length_(length), arguments_(arguments) { }
53 Object*& operator[] (int index) {
54 ASSERT(0 <= index && index < length_);
55 return arguments_[-index];
58 template <class S> Handle<S> at(int index) {
59 Object** value = &((*this)[index]);
60 // This cast checks that the object we're accessing does indeed have the
63 return Handle<S>(reinterpret_cast<S**>(value));
66 int smi_at(int index) {
67 return Smi::cast((*this)[index])->value();
70 double number_at(int index) {
71 return (*this)[index]->Number();
74 // Get the total number of arguments including the receiver.
75 int length() const { return length_; }
77 Object** arguments() { return arguments_; }
85 // Custom arguments replicate a small segment of stack that can be
86 // accessed through an Arguments object the same way the actual stack
88 class CustomArguments : public Relocatable {
90 inline CustomArguments(Isolate* isolate,
93 JSObject* holder) : Relocatable(isolate) {
94 ASSERT(reinterpret_cast<Object*>(isolate)->IsSmi());
98 values_[0] = reinterpret_cast<Object*>(isolate);
101 inline explicit CustomArguments(Isolate* isolate) : Relocatable(isolate) {
103 for (size_t i = 0; i < ARRAY_SIZE(values_); i++) {
104 values_[i] = reinterpret_cast<Object*>(kZapValue);
109 void IterateInstance(ObjectVisitor* v);
110 Object** end() { return values_ + ARRAY_SIZE(values_) - 1; }
117 #define DECLARE_RUNTIME_FUNCTION(Type, Name) \
118 Type Name(Arguments args, Isolate* isolate)
121 #define RUNTIME_FUNCTION(Type, Name) \
122 Type Name(Arguments args, Isolate* isolate)
125 #define RUNTIME_ARGUMENTS(isolate, args) args, isolate
128 } } // namespace v8::internal
130 #endif // V8_ARGUMENTS_H_