1 // Copyright 2003 Adam Megacz, see the COPYING file for licensing [GPL]
7 /** a JavaScript function, compiled into bytecode */
8 class CompiledFunctionImpl extends JS.Callable implements ByteCodes, Tokens {
10 // Fields and Accessors ///////////////////////////////////////////////
12 /** the number of formal arguments */
13 int numFormalArgs = 0;
15 /** the source code file that this block was drawn from */
16 private String sourceName;
17 public String getSourceName() throws JS.Exn { return sourceName; }
19 /** the line numbers */
20 private int[] line = new int[10];
22 /** the first line of this script */
23 private int firstLine = -1;
25 /** the instructions */
26 private int[] op = new int[10];
28 /** the arguments to the instructions */
29 private Object[] arg = new Object[10];
31 /** the number of instruction/argument pairs */
33 int size() { return size; }
35 /** the scope in which this function was declared; by default this function is called in a fresh subscope of the parentScope */
36 private JS.Scope parentScope;
38 // Constructors ////////////////////////////////////////////////////////
40 private CompiledFunctionImpl cloneWithNewParentScope(JS.Scope s) throws IOException {
41 CompiledFunctionImpl ret = new JS.CompiledFunction(sourceName, firstLine, null, s);
42 // Reuse the same op, arg, line, and size variables for the new "instance" of the function
43 // NOTE: Neither *this* function nor the new function should be modified after this call
51 protected CompiledFunctionImpl(String sourceName, int firstLine, Reader sourceCode, JS.Scope parentScope) throws IOException {
52 this.sourceName = sourceName;
53 this.firstLine = firstLine;
54 this.parentScope = parentScope;
55 if (sourceCode == null) return;
56 Parser p = new Parser(sourceCode, sourceName, firstLine);
59 p.parseStatement(this, null);
60 if (s == size()) break;
62 add(-1, LITERAL, null);
66 public Object call(JS.Array args) throws JS.Exn { return call(args, new FunctionScope(sourceName, parentScope)); }
67 public Object call(JS.Array args, JS.Scope scope) throws JS.Exn {
68 JS.Thread cx = JS.Thread.fromJavaThread(java.lang.Thread.currentThread());
69 CompiledFunction saved = cx.currentCompiledFunction;
71 cx.currentCompiledFunction = (CompiledFunction)this;
72 int size = cx.stack.size();
73 cx.stack.push(callMarker);
76 Object ret = cx.stack.pop();
77 if (cx.stack.size() > size)
78 // this should never happen
79 throw new Error("ERROR: stack grew by " + (cx.stack.size() - size) +
80 " elements during call at " + sourceName + ":" + firstLine);
84 while(cx.stack.size() > 0) if(cx.stack.pop() instanceof CallMarker) throw e;
85 throw new Error("CallMarker not found on the stack"); // should never happen
87 cx.currentCompiledFunction = saved;
92 // Adding and Altering Bytecodes ///////////////////////////////////////////////////
94 int get(int pos) { return op[pos]; }
95 Object getArg(int pos) { return arg[pos]; }
96 void set(int pos, int op_, Object arg_) { op[pos] = op_; arg[pos] = arg_; }
97 void set(int pos, Object arg_) { arg[pos] = arg_; }
98 int pop() { size--; arg[size] = null; return op[size]; }
99 void paste(CompiledFunctionImpl other) { for(int i=0; i<other.size; i++) add(other.line[i], other.op[i], other.arg[i]); }
100 CompiledFunctionImpl add(int line, int op_) { return add(line, op_, null); }
101 CompiledFunctionImpl add(int line, int op_, Object arg_) {
102 if (size == op.length - 1) {
103 int[] line2 = new int[op.length * 2]; System.arraycopy(this.line, 0, line2, 0, op.length); this.line = line2;
104 Object[] arg2 = new Object[op.length * 2]; System.arraycopy(arg, 0, arg2, 0, arg.length); arg = arg2;
105 int[] op2 = new int[op.length * 2]; System.arraycopy(op, 0, op2, 0, op.length); op = op2;
107 this.line[size] = line;
114 public int getLine(int pc) {
115 if(pc < 0 || pc >= size) return -1;
120 // Invoking the Bytecode ///////////////////////////////////////////////////////
122 void eval(JS.Scope s) {
123 final JS.Thread cx = JS.Thread.fromJavaThread(java.lang.Thread.currentThread());
124 final Vec t = cx.stack;
127 OUTER: for(pc=0; pc<size; pc++) {
132 Object curArg = arg[pc];
133 if(curOP == FINALLY_DONE) {
134 FinallyData fd = (FinallyData) t.pop();
135 if(fd == null) continue OUTER; // NOP
140 case LITERAL: t.push(arg[pc]); break;
141 case OBJECT: t.push(new JS.Obj()); break;
142 case ARRAY: t.push(new JS.Array(JS.toNumber(arg[pc]).intValue())); break;
143 case DECLARE: s.declare((String)(arg[pc]==null ? t.peek() : arg[pc])); if(arg[pc] != null) t.push(arg[pc]); break;
144 case TOPSCOPE: t.push(s); break;
145 case JT: if (JS.toBoolean(t.pop())) pc += JS.toNumber(arg[pc]).intValue() - 1; break;
146 case JF: if (!JS.toBoolean(t.pop())) pc += JS.toNumber(arg[pc]).intValue() - 1; break;
147 case JMP: pc += JS.toNumber(arg[pc]).intValue() - 1; break;
148 case POP: t.pop(); break;
149 case SWAP: { Object o1 = t.pop(); Object o2 = t.pop(); t.push(o1); t.push(o2); break; }
150 case DUP: t.push(t.peek()); break;
151 case NEWSCOPE: s = new JS.Scope(s); break;
152 case OLDSCOPE: s = s.getParentScope(); break;
153 case ASSERT: if (!JS.toBoolean(t.pop())) throw je("assertion failed"); break;
154 case BITNOT: t.push(new Long(~JS.toLong(t.pop()))); break;
155 case BANG: t.push(new Boolean(!JS.toBoolean(t.pop()))); break;
159 if (o == null) t.push(null);
160 else if (o instanceof JS) t.push(((JS)o).typeName());
161 else if (o instanceof String) t.push("string");
162 else if (o instanceof Number) t.push("number");
163 else if (o instanceof Boolean) t.push("boolean");
164 else t.push("unknown");
170 t.push(((CompiledFunctionImpl)arg[pc]).cloneWithNewParentScope(s));
171 } catch (IOException e) {
172 throw new Error("this should never happen");
179 Object[] keys = ((JS)o).keys();
180 JS.Array a = new JS.Array();
181 a.setSize(keys.length);
182 for(int j=0; j<keys.length; j++) a.setElementAt(keys[j], j);
189 t.push(new LoopMarker(pc, pc > 0 && op[pc - 1] == LABEL ? (String)arg[pc - 1] : (String)null,s));
190 t.push(Boolean.TRUE);
196 while(t.size() > 0) {
198 if (o instanceof CallMarker) ee("break or continue not within a loop");
199 if (o instanceof TryMarker) {
200 if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
201 t.push(new FinallyData(curOP, curArg));
202 s = ((TryMarker)o).scope;
203 pc = ((TryMarker)o).finallyLoc - 1;
206 if (o instanceof LoopMarker) {
207 if (curArg == null || curArg.equals(((LoopMarker)o).label)) {
208 int loopInstructionLocation = ((LoopMarker)o).location;
209 int endOfLoop = ((Integer)arg[loopInstructionLocation]).intValue() + loopInstructionLocation;
210 s = ((LoopMarker)o).scope;
211 if (curOP == CONTINUE) { t.push(o); t.push(Boolean.FALSE); }
212 pc = curOP == BREAK ? endOfLoop - 1 : loopInstructionLocation;
217 throw new Error("CONTINUE/BREAK invoked but couldn't find a LoopMarker at " + sourceName + ":" + getLine(pc));
220 int[] jmps = (int[]) arg[pc];
221 // jmps[0] is how far away the catch block is, jmps[1] is how far away the finally block is
222 // each can be < 0 if the specified block does not exist
223 t.push(new TryMarker(jmps[0] < 0 ? -1 : pc + jmps[0], jmps[1] < 0 ? -1 : pc + jmps[1],s));
228 Object retval = t.pop();
229 while(t.size() > 0) {
231 if (o instanceof TryMarker) {
232 if(((TryMarker)o).finallyLoc < 0) continue;
234 t.push(new FinallyData(RETURN));
235 s = ((TryMarker)o).scope;
236 pc = ((TryMarker)o).finallyLoc - 1;
239 if (o instanceof CallMarker) {
244 throw new Error("error: RETURN invoked but couldn't find a CallMarker!");
248 Object val = t.pop();
249 Object key = t.pop();
250 Object target = t.peek();
252 throw je("tried to put a value to the " + key + " property on the null value");
253 if (!(target instanceof JS))
254 throw je("tried to put a value to the " + key + " property on a " + target.getClass().getName());
256 throw je("tried to assign \"" + (val==null?"(null)":val.toString()) + "\" to the null key");
257 ((JS)target).put(key, val);
266 v = arg[pc] == null ? t.pop() : arg[pc];
274 if (o == null) throw je("tried to get property \"" + v + "\" from the null value");
275 if (v == null) throw je("tried to get the null key from " + o);
276 if (o instanceof String || o instanceof Number || o instanceof Boolean)
277 ret = Internal.getFromPrimitive(o,v);
278 else if (o instanceof JS)
279 ret = ((JS)o).get(v);
281 throw je("tried to get property " + v + " from a " + o.getClass().getName());
289 JS.Array arguments = new JS.Array();
290 int numArgs = JS.toNumber(arg[pc]).intValue();
291 arguments.setSize(numArgs);
292 for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(t.pop(), j);
294 if(o == null) throw je("attempted to call null");
296 if(op[pc] == CALLMETHOD) {
299 if(o instanceof String || o instanceof Number || o instanceof Boolean)
300 ret = Internal.callMethodOnPrimitive(o,method,arguments);
301 else if(o instanceof JS)
302 ret = ((JS)o).callMethod(method,arguments,false);
304 throw new JS.Exn("Tried to call a method on an object that isn't a JS object");
306 ret = ((JS.Callable)o).call(arguments);
311 // fall through if exception was thrown
314 if(o instanceof JS.Exn) throw (JS.Exn)o;
318 case INC: case DEC: {
319 boolean isPrefix = JS.toBoolean(arg[pc]);
320 Object key = t.pop();
321 JS obj = (JS)t.pop();
322 Number num = JS.toNumber(obj.get(key));
323 Number val = new Double(op[pc] == INC ? num.doubleValue() + 1.0 : num.doubleValue() - 1.0);
325 t.push(isPrefix ? val : num);
329 case ASSIGN_SUB: case ASSIGN_ADD: {
330 Object val = t.pop();
331 Object old = t.pop();
332 Object key = t.pop();
333 Object obj = t.peek();
334 if (val instanceof CompiledFunction) {
335 if (obj instanceof JS.Scope) {
336 JS.Scope parent = (JS.Scope)obj;
337 while(parent.getParentScope() != null) parent = parent.getParentScope();
338 if (parent instanceof org.xwt.Box) {
339 if (curOP == ASSIGN_ADD) {
340 ((org.xwt.Box)parent).addTrap(key, val);
342 ((org.xwt.Box)parent).delTrap(key, val);
344 // skip over the "normal" implementation of +=/-=
345 pc += ((Integer)arg[pc]).intValue() - 1;
350 // use the "normal" implementation
358 int count = ((Number)arg[pc]).intValue();
359 if(count < 2) throw new Error("this should never happen");
362 Object right = t.pop();
363 Object left = t.pop();
364 if(left instanceof String || right instanceof String) t.push(JS.toString(left).concat(JS.toString(right)));
365 else t.push(new Double(JS.toDouble(left) + JS.toDouble(right)));
367 Object[] args = new Object[count];
368 while(--count >= 0) args[count] = t.pop();
369 if(args[0] instanceof String) {
370 StringBuffer sb = new StringBuffer(64);
371 for(int i=0;i<args.length;i++) sb.append(JS.toString(args[i]));
372 t.push(sb.toString());
375 for(int i=0;i<args.length;i++) if(args[i] instanceof String) numStrings++;
376 if(numStrings == 0) {
378 for(int i=0;i<args.length;i++) d += JS.toDouble(args[i]);
379 t.push(new Double(d));
382 StringBuffer sb = new StringBuffer(64);
383 if(!(args[0] instanceof String || args[1] instanceof String)) {
386 d += JS.toDouble(args[i++]);
387 } while(!(args[i] instanceof String));
388 sb.append(JS.toString(new Double(d)));
390 while(i < args.length) sb.append(JS.toString(args[i++]));
391 t.push(sb.toString());
399 Object right = t.pop();
400 Object left = t.pop();
403 case BITOR: t.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
404 case BITXOR: t.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
405 case BITAND: t.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
407 case SUB: t.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
408 case MUL: t.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
409 case DIV: t.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
410 case MOD: t.push(new Double(JS.toDouble(left) % JS.toDouble(right))); break;
412 case LSH: t.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
413 case RSH: t.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
414 case URSH: t.push(new Long(JS.toLong(left) >>> JS.toLong(right))); break;
416 case LT: case LE: case GT: case GE: {
417 if (left == null) left = new Integer(0);
418 if (right == null) right = new Integer(0);
420 if (left instanceof String || right instanceof String) {
421 result = left.toString().compareTo(right.toString());
423 result = (int)java.lang.Math.ceil(JS.toDouble(left) - JS.toDouble(right));
425 t.push(new Boolean((op[pc] == LT && result < 0) || (op[pc] == LE && result <= 0) ||
426 (op[pc] == GT && result > 0) || (op[pc] == GE && result >= 0)));
435 if (l == null) { Object tmp = r; r = l; l = tmp; }
436 if (l == null && r == null) ret = true;
437 else if (r == null) ret = false; // l != null, so its false
438 else if (l instanceof Boolean) ret = new Boolean(JS.toBoolean(r)).equals(l);
439 else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
440 else if (l instanceof String) ret = r != null && l.equals(r.toString());
441 else ret = l.equals(r);
442 t.push(new Boolean(op[pc] == EQ ? ret : !ret)); break;
445 default: throw new Error("unknown opcode " + op[pc]);
449 while(t.size() > 0) {
451 if (o instanceof CatchMarker || o instanceof TryMarker) {
452 boolean inCatch = o instanceof CatchMarker;
455 if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
457 if(!inCatch && ((TryMarker)o).catchLoc >= 0) {
458 // run the catch block, this will implicitly run the finally block, if it exists
461 t.push(e.getObject());
462 s = ((TryMarker)o).scope;
463 pc = ((TryMarker)o).catchLoc - 1;
467 t.push(new FinallyData(THROW));
468 s = ((TryMarker)o).scope;
469 pc = ((TryMarker)o).finallyLoc - 1;
473 // no handler found within this func
474 if(o instanceof CallMarker) throw e;
476 throw new Error("couldn't find a Try or Call Marker!");
479 // this should never happen, we will ALWAYS have a RETURN at the end of the func
480 throw new Error("Just fell out of CompiledFunction::eval() loop. Last PC was " + lastPC);
483 // Debugging //////////////////////////////////////////////////////////////////////
485 public String toString() {
486 StringBuffer sb = new StringBuffer(1024);
487 sb.append("\n" + sourceName + ": " + firstLine + "\n");
488 for (int i=0; i < size; i++) {
492 sb.append(bytecodeToString[-op[i]]);
494 sb.append(codeToString[op[i]]);
496 sb.append(arg[i] == null ? "(no arg)" : arg[i]);
497 if((op[i] == JF || op[i] == JT || op[i] == JMP) && arg[i] != null && arg[i] instanceof Number) {
498 sb.append(" jump to ").append(i+((Number) arg[i]).intValue());
499 } else if(op[i] == TRY) {
500 int[] jmps = (int[]) arg[i];
501 sb.append(" catch: ").append(jmps[0] < 0 ? "No catch block" : ""+(i+jmps[0]));
502 sb.append(" finally: ").append(jmps[1] < 0 ? "No finally block" : ""+(i+jmps[1]));
506 return sb.toString();
509 // Exception Stuff ////////////////////////////////////////////////////////////////
511 static class EvaluatorException extends RuntimeException { public EvaluatorException(String s) { super(s); } }
512 EvaluatorException ee(String s) { throw new EvaluatorException(sourceName + ":" + JS.Thread.currentJSThread().getLine() + " " + s); }
513 JS.Exn je(String s) { throw new JS.Exn(sourceName + ":" + JS.Thread.currentJSThread().getLine() + " " + s); }
516 // FunctionScope /////////////////////////////////////////////////////////////////
518 private static class FunctionScope extends JS.Scope {
520 public FunctionScope(String sourceName, Scope parentScope) { super(parentScope); this.sourceName = sourceName; }
521 public String getSourceName() { return sourceName; }
525 // Markers //////////////////////////////////////////////////////////////////////
527 public static class CallMarker { public CallMarker() { } }
528 private static CallMarker callMarker = new CallMarker();
530 public static class CatchMarker { public CatchMarker() { } }
531 private static CatchMarker catchMarker = new CatchMarker();
533 public static class LoopMarker {
536 public JS.Scope scope;
537 public LoopMarker(int location, String label, JS.Scope scope) {
538 this.location = location;
543 public static class TryMarker {
545 public int finallyLoc;
546 public JS.Scope scope;
547 public TryMarker(int catchLoc, int finallyLoc, JS.Scope scope) {
548 this.catchLoc = catchLoc;
549 this.finallyLoc = finallyLoc;
553 public static class FinallyData {
556 public FinallyData(int op, Object arg) { this.op = op; this.arg = arg; }
557 public FinallyData(int op) { this(op,null); }
561 /** this class exists solely to work around a GCJ bug */
562 abstract class JSCallable extends JS.Callable {
563 public abstract Object call(JS.Array args) throws JS.Exn;