gecko-dev/js/js2/interpreter.cpp
beard%netscape.com baed85e41a NEW_ARRAY
2000-04-08 03:37:49 +00:00

318 lines
10 KiB
C++

// -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
//
// The contents of this file are subject to the Netscape Public
// License Version 1.1 (the "License"); you may not use this file
// except in compliance with the License. You may obtain a copy of
// the License at http://www.mozilla.org/NPL/
//
// Software distributed under the License is distributed on an "AS
// IS" basis, WITHOUT WARRANTY OF ANY KIND, either express oqr
// implied. See the License for the specific language governing
// rights and limitations under the License.
//
// The Original Code is the JavaScript 2 Prototype.
//
// The Initial Developer of the Original Code is Netscape
// Communications Corporation. Portions created by Netscape are
// Copyright (C) 1998 Netscape Communications Corporation. All
// Rights Reserved.
#include "interpreter.h"
#include "world.h"
#include <map>
namespace JavaScript {
using std::map;
using std::less;
using std::pair;
/**
* Private representation of a JavaScript object.
* This will change over time, so it is treated as an opaque
* type everywhere else but here.
*/
#if defined(XP_MAC)
// copied from default template parameters in map.
typedef gc_allocator<pair<const String, JSValue> > gc_map_allocator;
#elif defined(XP_UNIX)
// FIXME: in libg++, they assume the map's allocator is a byte allocator,
// which is wrapped in a simple_allocator. this is crap.
typedef char _Char[1];
typedef gc_allocator<_Char> gc_map_allocator;
#elif defined(_WIN32)
// FIXME: MSVC++'s notion. this is why we had to add _Charalloc().
typedef gc_allocator<JSValue> gc_map_allocator;
#endif
class JSObject : public map<String, JSValue, less<String>, gc_map_allocator> {
public:
void* operator new(size_t) { return alloc.allocate(1, 0); }
void operator delete(void* /* ptr */) {}
private:
static gc_allocator<JSObject> alloc;
};
/**
* Private representation of a JavaScript array.
*/
class JSArray : public JSObject {
public:
void* operator new(size_t) { return alloc.allocate(1, 0); }
uint32 length() { return elements.size(); }
JSValue& operator[](uint32 n)
{
// obviously, a sparse representation might be better.
uint32 size = elements.size();
if (n >= size) resize(n, size);
return elements[n];
}
private:
void resize(uint32 n, uint32 size)
{
do {
size *= 2;
} while (n >= size);
elements.resize(size);
}
private:
JSValues elements;
static gc_allocator<JSArray> alloc;
};
// static allocator (required when gc_allocator<T> is allocator<T>.
gc_allocator<JSObject> JSObject::alloc;
gc_allocator<JSArray> JSArray::alloc;
// operand access macros.
#define op1(i) (i->itsOperand1)
#define op2(i) (i->itsOperand2)
#define op3(i) (i->itsOperand3)
// mnemonic names for operands.
#define dst(i) op1(i)
#define src1(i) op2(i)
#define src2(i) op3(i)
JSValue interpret(ICodeModule *iCode, const JSValues& args)
{
// fake global variables object.
static JSObject globals;
JSValue result;
JSValues frame(args);
JSValues registers(iCode->itsMaxRegister + 1);
// ensure that frame is large enough.
uint32 frameSize = iCode->itsMaxVariable + 1;
if (frameSize > frame.size())
frame.resize(frameSize);
InstructionIterator begin_pc = iCode->its_iCode->begin();
InstructionIterator end_pc = iCode->its_iCode->end();
InstructionIterator pc = begin_pc;
while (pc != end_pc) {
Instruction* instruction = *pc;
switch (instruction->opcode()) {
case MOVE_TO:
{
Move* mov = static_cast<Move*>(instruction);
registers[dst(mov)] = registers[src1(mov)];
}
break;
case LOAD_NAME:
{
LoadName* ln = static_cast<LoadName*>(instruction);
registers[dst(ln)] = globals[*src1(ln)];
}
break;
case SAVE_NAME:
{
SaveName* sn = static_cast<SaveName*>(instruction);
globals[*dst(sn)] = registers[src1(sn)];
}
break;
case NEW_OBJECT:
{
NewObject* no = static_cast<NewObject*>(instruction);
registers[dst(no)].object = new JSObject();
}
break;
case NEW_ARRAY:
{
NewArray* na = static_cast<NewArray*>(instruction);
registers[dst(na)].array = new JSArray();
}
break;
case GET_PROP:
{
GetProp* gp = static_cast<GetProp*>(instruction);
JSObject* object = registers[src1(gp)].object;
registers[dst(gp)] = (*object)[*src2(gp)];
}
break;
case SET_PROP:
{
SetProp* sp = static_cast<SetProp*>(instruction);
JSObject* object = registers[dst(sp)].object;
(*object)[*src1(sp)] = registers[src2(sp)];
}
break;
case GET_ELEMENT:
{
GetElement* ge = static_cast<GetElement*>(instruction);
JSArray* array = registers[src1(ge)].array;
registers[dst(ge)] = (*array)[src2(ge)];
}
break;
case SET_ELEMENT:
{
SetElement* se = static_cast<SetElement*>(instruction);
JSArray* array = registers[dst(se)].array;
(*array)[src1(se)] = registers[src2(se)];
}
break;
case LOAD_IMMEDIATE:
{
LoadImmediate* li = static_cast<LoadImmediate*>(instruction);
registers[dst(li)] = JSValue(src1(li));
}
break;
case LOAD_VAR:
{
LoadVar* lv = static_cast<LoadVar*>(instruction);
registers[dst(lv)] = frame[src1(lv)];
}
break;
case SAVE_VAR:
{
SaveVar* sv = static_cast<SaveVar*>(instruction);
frame[dst(sv)] = registers[src1(sv)];
}
break;
case BRANCH:
{
ResolvedBranch* bra = static_cast<ResolvedBranch*>(instruction);
pc = begin_pc + dst(bra);
continue;
}
break;
case BRANCH_LT:
{
ResolvedBranchCond* bc = static_cast<ResolvedBranchCond*>(instruction);
if (registers[src1(bc)].i32 < 0) {
pc = begin_pc + dst(bc);
continue;
}
}
break;
case BRANCH_LE:
{
ResolvedBranchCond* bc = static_cast<ResolvedBranchCond*>(instruction);
if (registers[src1(bc)].i32 <= 0) {
pc = begin_pc + dst(bc);
continue;
}
}
break;
case BRANCH_EQ:
{
ResolvedBranchCond* bc = static_cast<ResolvedBranchCond*>(instruction);
if (registers[src1(bc)].i32 == 0) {
pc = begin_pc + dst(bc);
continue;
}
}
break;
case BRANCH_NE:
{
ResolvedBranchCond* bc = static_cast<ResolvedBranchCond*>(instruction);
if (registers[src1(bc)].i32 != 0) {
pc = begin_pc + dst(bc);
continue;
}
}
break;
case BRANCH_GE:
{
ResolvedBranchCond* bc = static_cast<ResolvedBranchCond*>(instruction);
if (registers[src1(bc)].i32 >= 0) {
pc = begin_pc + dst(bc);
continue;
}
}
break;
case BRANCH_GT:
{
ResolvedBranchCond* bc = static_cast<ResolvedBranchCond*>(instruction);
if (registers[src1(bc)].i32 > 0) {
pc = begin_pc + dst(bc);
continue;
}
}
break;
case ADD:
{
// could get clever here with Functional forms.
Arithmetic* add = static_cast<Arithmetic*>(instruction);
registers[dst(add)] = JSValue(registers[src1(add)].f64 + registers[src2(add)].f64);
}
break;
case SUBTRACT:
{
Arithmetic* sub = static_cast<Arithmetic*>(instruction);
registers[dst(sub)] = JSValue(registers[src1(sub)].f64 - registers[src2(sub)].f64);
}
break;
case MULTIPLY:
{
Arithmetic* mul = static_cast<Arithmetic*>(instruction);
registers[dst(mul)] = JSValue(registers[src1(mul)].f64 * registers[src2(mul)].f64);
}
break;
case DIVIDE:
{
Arithmetic* div = static_cast<Arithmetic*>(instruction);
registers[dst(div)] = JSValue(registers[src1(div)].f64 / registers[src2(div)].f64);
}
break;
case COMPARE_LT:
case COMPARE_LE:
case COMPARE_EQ:
case COMPARE_NE:
case COMPARE_GT:
case COMPARE_GE:
{
Arithmetic* cmp = static_cast<Arithmetic*>(instruction);
float64 diff = (registers[src1(cmp)].f64 - registers[src2(cmp)].f64);
registers[dst(cmp)].i32 = (diff == 0.0 ? 0 : (diff > 0.0 ? 1 : -1));
}
break;
case NOT:
{
Move* nt = static_cast<Move*>(instruction);
registers[dst(nt)].i32 = !registers[src1(nt)].i32;
}
break;
case RETURN:
{
Return* ret = static_cast<Return*>(instruction);
result = registers[op1(ret)];
return result;
}
break;
default:
break;
}
// increment the program counter.
++pc;
}
return result;
}
}