--- /dev/null
+// Copyright 2003 Adam Megacz, see the COPYING file for licensing [GPL]
+package org.xwt.js;
+
+import org.xwt.util.*;
+import java.util.*;
+import java.io.*;
+
+class Interpreter implements ByteCodes, Tokens {
+
+ static Object eval(final JSContext cx) throws JS.Exn {
+ final int initialPauseCount = cx.pausecount;
+ OUTER: for(;; cx.pc++) {
+ try {
+ if (cx.f == null || cx.pc >= cx.f.size) return cx.stack.pop();
+ int op = cx.f.op[cx.pc];
+ Object arg = cx.f.arg[cx.pc];
+ if(op == FINALLY_DONE) {
+ FinallyData fd = (FinallyData) cx.stack.pop();
+ if(fd == null) continue OUTER; // NOP
+ op = fd.op;
+ arg = fd.arg;
+ }
+ switch(op) {
+ case LITERAL: cx.stack.push(arg); break;
+ case OBJECT: cx.stack.push(new JS()); break;
+ case ARRAY: cx.stack.push(new JSArray(JS.toNumber(arg).intValue())); break;
+ case DECLARE: cx.scope.declare((String)(arg==null ? cx.stack.peek() : arg)); if(arg != null) cx.stack.push(arg); break;
+ case TOPSCOPE: cx.stack.push(cx.scope); break;
+ case JT: if (JS.toBoolean(cx.stack.pop())) cx.pc += JS.toNumber(arg).intValue() - 1; break;
+ case JF: if (!JS.toBoolean(cx.stack.pop())) cx.pc += JS.toNumber(arg).intValue() - 1; break;
+ case JMP: cx.pc += JS.toNumber(arg).intValue() - 1; break;
+ case POP: cx.stack.pop(); break;
+ case SWAP: {
+ int depth = (arg == null ? 1 : JS.toInt(arg));
+ Object save = cx.stack.elementAt(cx.stack.size() - 1);
+ for(int i=cx.stack.size() - 1; i > cx.stack.size() - 1 - depth; i--)
+ cx.stack.setElementAt(cx.stack.elementAt(i-1), i);
+ cx.stack.setElementAt(save, cx.stack.size() - depth - 1);
+ break; }
+ case DUP: cx.stack.push(cx.stack.peek()); break;
+ case NEWSCOPE: cx.scope = new JSScope(cx.scope); break;
+ case OLDSCOPE: cx.scope = cx.scope.getParentJSScope(); break;
+ case ASSERT: if (!JS.toBoolean(cx.stack.pop())) throw je("assertion failed"); break;
+ case BITNOT: cx.stack.push(new Long(~JS.toLong(cx.stack.pop()))); break;
+ case BANG: cx.stack.push(new Boolean(!JS.toBoolean(cx.stack.pop()))); break;
+ case NEWFUNCTION: cx.stack.push(((JSFunction)arg).cloneWithNewParentJSScope(cx.scope)); break;
+ case LABEL: break;
+
+ case TYPEOF: {
+ Object o = cx.stack.pop();
+ if (o == null) cx.stack.push(null);
+ else if (o instanceof JS) cx.stack.push(((JS)o).typeName());
+ else if (o instanceof String) cx.stack.push("string");
+ else if (o instanceof Number) cx.stack.push("number");
+ else if (o instanceof Boolean) cx.stack.push("boolean");
+ else cx.stack.push("unknown");
+ break;
+ }
+
+ case PUSHKEYS: {
+ Object o = cx.stack.peek();
+ Enumeration e = ((JS)o).keys();
+ JSArray a = new JSArray();
+ while(e.hasMoreElements()) a.addElement(e.nextElement());
+ cx.stack.push(a);
+ break;
+ }
+
+ case LOOP:
+ cx.stack.push(new LoopMarker(cx.pc, cx.pc > 0 && cx.f.op[cx.pc - 1] == LABEL ?
+ (String)cx.f.arg[cx.pc - 1] : (String)null, cx.scope));
+ cx.stack.push(Boolean.TRUE);
+ break;
+
+ case BREAK:
+ case CONTINUE:
+ while(cx.stack.size() > 0) {
+ Object o = cx.stack.pop();
+ if (o instanceof CallMarker) ee("break or continue not within a loop");
+ if (o instanceof TryMarker) {
+ if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
+ cx.stack.push(new FinallyData(op, arg));
+ cx.scope = ((TryMarker)o).scope;
+ cx.pc = ((TryMarker)o).finallyLoc - 1;
+ continue OUTER;
+ }
+ if (o instanceof LoopMarker) {
+ if (arg == null || arg.equals(((LoopMarker)o).label)) {
+ int loopInstructionLocation = ((LoopMarker)o).location;
+ int endOfLoop = ((Integer)cx.f.arg[loopInstructionLocation]).intValue() + loopInstructionLocation;
+ cx.scope = ((LoopMarker)o).scope;
+ if (op == CONTINUE) { cx.stack.push(o); cx.stack.push(Boolean.FALSE); }
+ cx.pc = op == BREAK ? endOfLoop - 1 : loopInstructionLocation;
+ continue OUTER;
+ }
+ }
+ }
+ throw new Error("CONTINUE/BREAK invoked but couldn't find LoopMarker at " +
+ cx.getSourceName() + ":" + cx.getLine());
+
+ case TRY: {
+ int[] jmps = (int[]) arg;
+ // jmps[0] is how far away the catch block is, jmps[1] is how far away the finally block is
+ // each can be < 0 if the specified block does not exist
+ cx.stack.push(new TryMarker(jmps[0] < 0 ? -1 : cx.pc + jmps[0], jmps[1] < 0 ? -1 : cx.pc + jmps[1], cx.scope));
+ break;
+ }
+
+ case RETURN: {
+ Object retval = cx.stack.pop();
+ while(cx.stack.size() > 0) {
+ Object o = cx.stack.pop();
+ if (o instanceof TryMarker) {
+ if(((TryMarker)o).finallyLoc < 0) continue;
+ cx.stack.push(retval);
+ cx.stack.push(new FinallyData(RETURN));
+ cx.scope = ((TryMarker)o).scope;
+ cx.pc = ((TryMarker)o).finallyLoc - 1;
+ continue OUTER;
+ } else if (o instanceof CallMarker) {
+ if (cx.scope instanceof JSTrap.JSTrapScope) {
+ JSTrap.JSTrapScope ts = (JSTrap.JSTrapScope)cx.scope;
+ if (!ts.cascadeHappened) {
+ ts.cascadeHappened = true;
+ JSTrap t = ts.t.next;
+ while (t != null && t.f.numFormalArgs == 0) t = t.next;
+ if (t == null) {
+ ((JS)ts.t.trapee).put(t.name, ts.val);
+ if (cx.pausecount > initialPauseCount) return null; // we were paused
+ } else {
+ cx.stack.push(o);
+ JSArray args = new JSArray();
+ args.addElement(ts.val);
+ cx.stack.push(args);
+ cx.f = t.f;
+ cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, ts.val);
+ cx.pc = -1;
+ break;
+ }
+ }
+ }
+ cx.scope = ((CallMarker)o).scope;
+ cx.pc = ((CallMarker)o).pc;
+ cx.f = (JSFunction)((CallMarker)o).f;
+ cx.stack.push(retval);
+ continue OUTER;
+ }
+ }
+ throw new Error("error: RETURN invoked but couldn't find a CallMarker!");
+ }
+
+ case PUT: {
+ Object val = cx.stack.pop();
+ Object key = cx.stack.pop();
+ Object target = cx.stack.peek();
+ if (target == null)
+ throw je("tried to put a value to the " + key + " property on the null value");
+ if (!(target instanceof JS))
+ throw je("tried to put a value to the " + key + " property on a " + target.getClass().getName());
+ if (key == null)
+ throw je("tried to assign \"" + (val==null?"(null)":val.toString()) + "\" to the null key");
+ JSTrap t = null;
+ if (target instanceof JSTrap.JSTrappable) {
+ t = ((JSTrap.JSTrappable)target).getTrap(val);
+ while (t != null && t.f.numFormalArgs == 0) t = t.next;
+ } else if (target instanceof JSTrap.JSTrapScope && key.equals("cascade")) {
+ JSTrap.JSTrapScope ts = (JSTrap.JSTrapScope)target;
+ t = ts.t.next;
+ ts.cascadeHappened = true;
+ while (t != null && t.f.numFormalArgs == 0) t = t.next;
+ if (t == null) target = ts.t.trapee;
+ }
+ if (t != null) {
+ cx.stack.push(new CallMarker(cx));
+ JSArray args = new JSArray();
+ args.addElement(val);
+ cx.stack.push(args);
+ cx.f = t.f;
+ cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, val);
+ cx.pc = -1;
+ break;
+ }
+ ((JS)target).put(key, val);
+ if (cx.pausecount > initialPauseCount) return null; // we were paused
+ cx.stack.push(val);
+ break;
+ }
+
+ case GET:
+ case GET_PRESERVE: {
+ Object o, v;
+ if (op == GET) {
+ v = arg == null ? cx.stack.pop() : arg;
+ o = cx.stack.pop();
+ } else {
+ v = cx.stack.pop();
+ o = cx.stack.peek();
+ cx.stack.push(v);
+ }
+ Object ret = null;
+ if (v == null) throw je("tried to get the null key from " + o);
+ if (o == null) throw je("tried to get property \"" + v + "\" from the null value @" + cx.pc + "\n" + cx.f.dump());
+ if (o instanceof String || o instanceof Number || o instanceof Boolean) {
+ ret = Internal.getFromPrimitive(o,v);
+ cx.stack.push(ret);
+ break;
+ } else if (o instanceof JS) {
+ JSTrap t = null;
+ if (o instanceof JSTrap.JSTrappable) {
+ t = ((JSTrap.JSTrappable)o).getTrap(v);
+ while (t != null && t.f.numFormalArgs != 0) t = t.next;
+ } else if (o instanceof JSTrap.JSTrapScope && v.equals("cascade")) {
+ t = ((JSTrap.JSTrapScope)o).t.next;
+ while (t != null && t.f.numFormalArgs != 0) t = t.next;
+ if (t == null) o = ((JSTrap.JSTrapScope)o).t.trapee;
+ }
+ if (t != null) {
+ cx.stack.push(new CallMarker(cx));
+ JSArray args = new JSArray();
+ cx.stack.push(args);
+ cx.f = t.f;
+ cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, null);
+ ((JSTrap.JSTrapScope)cx.scope).cascadeHappened = true;
+ cx.pc = -1;
+ break;
+ }
+ ret = ((JS)o).get(v);
+ if (ret == JSCallable.METHOD) ret = new Internal.JSCallableStub((JS)o, v);
+ if (cx.pausecount > initialPauseCount) return null; // we were paused
+ cx.stack.push(ret);
+ break;
+ }
+ throw je("tried to get property " + v + " from a " + o.getClass().getName());
+ }
+
+ case CALL: case CALLMETHOD: {
+ int numArgs = JS.toInt(arg);
+ Object method = null;
+ Object ret = null;
+ Object object = cx.stack.pop();
+
+ if (op == CALL) {
+ object = cx.stack.pop();
+ } else if (object == JSCallable.METHOD) {
+ method = cx.stack.pop();
+ object = cx.stack.pop();
+ }
+
+ if (object instanceof String || object instanceof Number || object instanceof Boolean) {
+ JSArray arguments = new JSArray();
+ for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
+ ret = Internal.callMethodOnPrimitive(object, method, arguments);
+
+ } else if (object instanceof JSFunction) {
+ // FEATURE: use something similar to call0/call1/call2 here
+ JSArray arguments = new JSArray();
+ for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
+ cx.stack.push(new CallMarker(cx));
+ cx.stack.push(arguments);
+ cx.f = (JSFunction)object;
+ cx.scope = new JSScope(cx.f.parentJSScope);
+ cx.pc = -1;
+ break;
+
+ } else if (object instanceof JSCallable) {
+ JSCallable c = (JSCallable)object;
+ Object[] rest = numArgs > 3 ? new Object[numArgs - 3] : null;
+ for(int i=numArgs - 1; i>2; i--) rest[i-3] = cx.stack.pop();
+ Object a2 = numArgs <= 2 ? null : cx.stack.pop();
+ Object a1 = numArgs <= 1 ? null : cx.stack.pop();
+ Object a0 = numArgs <= 0 ? null : cx.stack.pop();
+ ret = c.callMethod(method, a0, a1, a2, rest, numArgs);
+
+ } else {
+ throw new JS.Exn("can't call a " + object.getClass().getName() + " @" + cx.pc + "\n" + cx.f.dump());
+
+ }
+ if (cx.pausecount > initialPauseCount) return null;
+ cx.stack.push(ret);
+ break;
+ }
+
+ case THROW: {
+ Object o = cx.stack.pop();
+ if(o instanceof JS.Exn) throw (JS.Exn)o;
+ throw new JS.Exn(o);
+ }
+
+ case ASSIGN_SUB: case ASSIGN_ADD: {
+ Object val = cx.stack.pop();
+ Object old = cx.stack.pop();
+ Object key = cx.stack.pop();
+ Object obj = cx.stack.peek();
+ if (val instanceof JSFunction && obj instanceof JSScope) {
+ JSScope parent = (JSScope)obj;
+ while(parent.getParentJSScope() != null) parent = parent.getParentJSScope();
+ if (parent instanceof JSTrap.JSTrappable) {
+ JSTrap.JSTrappable b = (JSTrap.JSTrappable)parent;
+ if (op == ASSIGN_ADD) JSTrap.addTrap(b, key, (JSFunction)val);
+ else JSTrap.delTrap(b, key, (JSFunction)val);
+ // skip over the "normal" implementation of +=/-=
+ cx.pc += ((Integer)arg).intValue() - 1;
+ break;
+ }
+ }
+ // use the "normal" implementation
+ cx.stack.push(key);
+ cx.stack.push(old);
+ cx.stack.push(val);
+ break;
+ }
+
+ case ADD: {
+ int count = ((Number)arg).intValue();
+ if(count < 2) throw new Error("this should never happen");
+ if(count == 2) {
+ // common case
+ Object right = cx.stack.pop();
+ Object left = cx.stack.pop();
+ if(left instanceof String || right instanceof String)
+ cx.stack.push(JS.toString(left).concat(JS.toString(right)));
+ else cx.stack.push(new Double(JS.toDouble(left) + JS.toDouble(right)));
+ } else {
+ Object[] args = new Object[count];
+ while(--count >= 0) args[count] = cx.stack.pop();
+ if(args[0] instanceof String) {
+ StringBuffer sb = new StringBuffer(64);
+ for(int i=0;i<args.length;i++) sb.append(JS.toString(args[i]));
+ cx.stack.push(sb.toString());
+ } else {
+ int numStrings = 0;
+ for(int i=0;i<args.length;i++) if(args[i] instanceof String) numStrings++;
+ if(numStrings == 0) {
+ double d = 0.0;
+ for(int i=0;i<args.length;i++) d += JS.toDouble(args[i]);
+ cx.stack.push(new Double(d));
+ } else {
+ int i=0;
+ StringBuffer sb = new StringBuffer(64);
+ if(!(args[0] instanceof String || args[1] instanceof String)) {
+ double d=0.0;
+ do {
+ d += JS.toDouble(args[i++]);
+ } while(!(args[i] instanceof String));
+ sb.append(JS.toString(new Double(d)));
+ }
+ while(i < args.length) sb.append(JS.toString(args[i++]));
+ cx.stack.push(sb.toString());
+ }
+ }
+ }
+ break;
+ }
+
+ default: {
+ Object right = cx.stack.pop();
+ Object left = cx.stack.pop();
+ switch(op) {
+
+ case BITOR: cx.stack.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
+ case BITXOR: cx.stack.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
+ case BITAND: cx.stack.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
+
+ case SUB: cx.stack.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
+ case MUL: cx.stack.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
+ case DIV: cx.stack.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
+ case MOD: cx.stack.push(new Double(JS.toDouble(left) % JS.toDouble(right))); break;
+
+ case LSH: cx.stack.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
+ case RSH: cx.stack.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
+ case URSH: cx.stack.push(new Long(JS.toLong(left) >>> JS.toLong(right))); break;
+
+ case LT: case LE: case GT: case GE: {
+ if (left == null) left = new Integer(0);
+ if (right == null) right = new Integer(0);
+ int result = 0;
+ if (left instanceof String || right instanceof String) {
+ result = left.toString().compareTo(right.toString());
+ } else {
+ result = (int)java.lang.Math.ceil(JS.toDouble(left) - JS.toDouble(right));
+ }
+ cx.stack.push(new Boolean((op == LT && result < 0) || (op == LE && result <= 0) ||
+ (op == GT && result > 0) || (op == GE && result >= 0)));
+ break;
+ }
+
+ case EQ:
+ case NE: {
+ Object l = left;
+ Object r = right;
+ boolean ret;
+ if (l == null) { Object tmp = r; r = l; l = tmp; }
+ if (l == null && r == null) ret = true;
+ else if (r == null) ret = false; // l != null, so its false
+ else if (l instanceof Boolean) ret = new Boolean(JS.toBoolean(r)).equals(l);
+ else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
+ else if (l instanceof String) ret = r != null && l.equals(r.toString());
+ else ret = l.equals(r);
+ cx.stack.push(new Boolean(op == EQ ? ret : !ret)); break;
+ }
+
+ default: throw new Error("unknown opcode " + op);
+ } }
+ }
+
+ } catch(JS.Exn e) {
+ while(cx.stack.size() > 0) {
+ Object o = cx.stack.pop();
+ if (o instanceof CatchMarker || o instanceof TryMarker) {
+ boolean inCatch = o instanceof CatchMarker;
+ if(inCatch) {
+ o = cx.stack.pop();
+ if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
+ }
+ if(!inCatch && ((TryMarker)o).catchLoc >= 0) {
+ // run the catch block, this will implicitly run the finally block, if it exists
+ cx.stack.push(o);
+ cx.stack.push(catchMarker);
+ cx.stack.push(e.getObject());
+ cx.scope = ((TryMarker)o).scope;
+ cx.pc = ((TryMarker)o).catchLoc - 1;
+ continue OUTER;
+ } else {
+ cx.stack.push(e);
+ cx.stack.push(new FinallyData(THROW));
+ cx.scope = ((TryMarker)o).scope;
+ cx.pc = ((TryMarker)o).finallyLoc - 1;
+ continue OUTER;
+ }
+ }
+ // no handler found within this func
+ if(o instanceof CallMarker) throw e;
+ }
+ throw e;
+ } // end try/catch
+ } // end for
+ }
+
+ // Exception Stuff ////////////////////////////////////////////////////////////////
+
+ static class EvaluatorException extends RuntimeException { public EvaluatorException(String s) { super(s); } }
+ static EvaluatorException ee(String s) {
+ throw new EvaluatorException(JSContext.getSourceName() + ":" + JSContext.getLine() + " " + s);
+ }
+ static JS.Exn je(String s) {
+ throw new JS.Exn(JSContext.getSourceName() + ":" + JSContext.getLine() + " " + s);
+ }
+
+
+ // Markers //////////////////////////////////////////////////////////////////////
+
+ public static class CallMarker {
+ int pc;
+ JSScope scope;
+ JSFunction f;
+ public CallMarker(JSContext cx) { pc = cx.pc + 1; scope = cx.scope; f = cx.f; }
+ }
+
+ public static class CatchMarker { public CatchMarker() { } }
+ private static CatchMarker catchMarker = new CatchMarker();
+
+ public static class LoopMarker {
+ public int location;
+ public String label;
+ public JSScope scope;
+ public LoopMarker(int location, String label, JSScope scope) {
+ this.location = location;
+ this.label = label;
+ this.scope = scope;
+ }
+ }
+ public static class TryMarker {
+ public int catchLoc;
+ public int finallyLoc;
+ public JSScope scope;
+ public TryMarker(int catchLoc, int finallyLoc, JSScope scope) {
+ this.catchLoc = catchLoc;
+ this.finallyLoc = finallyLoc;
+ this.scope = scope;
+ }
+ }
+ public static class FinallyData {
+ public int op;
+ public Object arg;
+ public FinallyData(int op, Object arg) { this.op = op; this.arg = arg; }
+ public FinallyData(int op) { this(op,null); }
+ }
+}
projects / org.ibex.core.git / commitdiff