Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 1 | // Copyright 2006-2008 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 |
| 4 | // met: |
| 5 | // |
| 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. |
| 15 | // |
| 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. |
| 27 | |
| 28 | #ifndef V8_ARGUMENTS_H_ |
| 29 | #define V8_ARGUMENTS_H_ |
| 30 | |
| 31 | namespace v8 { |
| 32 | namespace internal { |
| 33 | |
| 34 | // Arguments provides access to runtime call parameters. |
| 35 | // |
| 36 | // It uses the fact that the instance fields of Arguments |
| 37 | // (length_, arguments_) are "overlayed" with the parameters |
| 38 | // (no. of parameters, and the parameter pointer) passed so |
| 39 | // that inside the C++ function, the parameters passed can |
| 40 | // be accessed conveniently: |
| 41 | // |
| 42 | // Object* Runtime_function(Arguments args) { |
| 43 | // ... use args[i] here ... |
| 44 | // } |
| 45 | |
| 46 | class Arguments BASE_EMBEDDED { |
| 47 | public: |
| 48 | Arguments(int length, Object** arguments) |
| 49 | : length_(length), arguments_(arguments) { } |
| 50 | |
| 51 | Object*& operator[] (int index) { |
| 52 | ASSERT(0 <= index && index < length_); |
| 53 | return arguments_[-index]; |
| 54 | } |
| 55 | |
| 56 | template <class S> Handle<S> at(int index) { |
| 57 | Object** value = &((*this)[index]); |
| 58 | // This cast checks that the object we're accessing does indeed have the |
| 59 | // expected type. |
| 60 | S::cast(*value); |
| 61 | return Handle<S>(reinterpret_cast<S**>(value)); |
| 62 | } |
| 63 | |
| 64 | // Get the total number of arguments including the receiver. |
| 65 | int length() const { return length_; } |
| 66 | |
| 67 | Object** arguments() { return arguments_; } |
| 68 | |
| 69 | private: |
| 70 | int length_; |
| 71 | Object** arguments_; |
| 72 | }; |
| 73 | |
| 74 | |
| 75 | // Cursom arguments replicate a small segment of stack that can be |
| 76 | // accessed through an Arguments object the same way the actual stack |
| 77 | // can. |
| 78 | class CustomArguments : public Relocatable { |
| 79 | public: |
Steve Block | d0582a6 | 2009-12-15 09:54:21 +0000 | [diff] [blame^] | 80 | inline CustomArguments(Object* data, |
| 81 | JSObject* self, |
| 82 | JSObject* holder) { |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 83 | values_[3] = self; |
| 84 | values_[2] = holder; |
| 85 | values_[1] = Smi::FromInt(0); |
| 86 | values_[0] = data; |
| 87 | } |
| 88 | void IterateInstance(ObjectVisitor* v); |
| 89 | Object** end() { return values_ + 3; } |
| 90 | private: |
| 91 | Object* values_[4]; |
| 92 | }; |
| 93 | |
| 94 | |
| 95 | } } // namespace v8::internal |
| 96 | |
| 97 | #endif // V8_ARGUMENTS_H_ |