// Constructors //////////////////////////////////////////////////////
- public Parser(Reader r, String sourceName, int line) throws IOException { super(r, sourceName, line); }
+ private Parser(Reader r, String sourceName, int line) throws IOException { super(r, sourceName, line); }
/** for debugging */
public static void main(String[] s) throws IOException {
System.out.println(block);
}
-
// Statics ////////////////////////////////////////////////////////////
static byte[] precedence = new byte[MAX_TOKEN + 1];
precedence[DOT] = precedence[LB] = precedence[LP] = precedence[INC] = precedence[DEC] = 15;
}
-
+ // Local variable management
+ Vec scopeStack = new Vec();
+ static class ScopeInfo {
+ int base;
+ int end;
+ int newScopeInsn;
+ Hash mapping = new Hash();
+ }
+ Hash globalCache = new Hash();
+ JS scopeKey(String name) {
+ if(globalCache.get(name) != null) return null;
+ for(int i=scopeStack.size()-1;i>=0;i--) {
+ JS key = (JS)((ScopeInfo) scopeStack.elementAt(i)).mapping.get(name);
+ if(key != null) return key;
+ }
+ globalCache.put(name,Boolean.TRUE);
+ return null;
+ }
+ void scopeDeclare(String name) throws IOException {
+ ScopeInfo si = (ScopeInfo) scopeStack.lastElement();
+ if(si.mapping.get(name) != null) throw pe("" + name + " already declared in this scope");
+ si.mapping.put(name,JS.N(si.end++));
+ globalCache.put(name,null);
+ }
+ void scopePush(JSFunction b) {
+ ScopeInfo prev = (ScopeInfo) scopeStack.lastElement();
+ ScopeInfo si = new ScopeInfo();
+ si.base = prev.end;
+ si.end = si.base;
+ si.newScopeInsn = b.size;
+ scopeStack.push(si);
+ b.add(parserLine, NEWSCOPE);
+ }
+ void scopePop(JSFunction b) {
+ ScopeInfo si = (ScopeInfo) scopeStack.pop();
+ b.add(parserLine, OLDSCOPE);
+ b.set(si.newScopeInsn,JS.N((si.base<<16)|((si.end-si.base)<<0)));
+ }
+
+
// Parsing Logic /////////////////////////////////////////////////////////
+
+ /** parse and compile a function */
+ public static JSFunction fromReader(String sourceName, int firstLine, Reader sourceCode) throws IOException {
+ JSFunction ret = new JSFunction(sourceName, firstLine, null);
+ if (sourceCode == null) return ret;
+ Parser p = new Parser(sourceCode, sourceName, firstLine);
+ p.scopeStack.setSize(0);
+ p.scopeStack.push(new ScopeInfo());
+ p.scopePush(ret);
+ while(true) {
+ //int s = ret.size;
+ if(p.peekToken() == -1) break; // FIXME: Check this logic one more time
+ p.parseStatement(ret, null);
+ //if (s == ret.size) break;
+ }
+ p.scopePop(ret);
+ if(p.scopeStack.size() != 1) throw new Error("scopeStack height mismatch");
+ ret.add(-1, LITERAL, null);
+ ret.add(-1, RETURN);
+ return ret;
+ }
/** gets a token and throws an exception if it is not <tt>code</tt> */
private void consume(int code) throws IOException {
// (.foo) syntax
case DOT: {
consume(NAME);
- b.add(parserLine, TOPSCOPE);
- b.add(parserLine, LITERAL, JSString.intern(""));
- b.add(parserLine, GET);
- b.add(parserLine, LITERAL, JSString.intern(string));
- b.add(parserLine, GET);
- continueExpr(b, minPrecedence);
+ b.add(parserLine, GLOBALSCOPE);
+ b.add(parserLine, GET, JS.S("",true));
+ b.add(parserLine, LITERAL, JS.S(string,true));
+ continueExprAfterAssignable(b,minPrecedence,null);
break;
}
case INC: case DEC: { // prefix (not postfix)
startExpr(b, precedence[tok]);
int prev = b.size - 1;
+ boolean sg = b.get(prev) == SCOPEGET;
if (b.get(prev) == GET && b.getArg(prev) != null)
b.set(prev, LITERAL, b.getArg(prev));
else if(b.get(prev) == GET)
b.pop();
- else
+ else if(!sg)
throw pe("prefixed increment/decrement can only be performed on a valid assignment target");
- b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
+ if(!sg) b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
b.add(parserLine, LITERAL, JS.N(1));
b.add(parserLine, tok == INC ? ADD : SUB, JS.N(2));
- b.add(parserLine, PUT, null);
- b.add(parserLine, SWAP, null);
- b.add(parserLine, POP, null);
+ if(sg) {
+ b.add(parserLine, SCOPEPUT, b.getArg(prev));
+ } else {
+ b.add(parserLine, PUT, null);
+ b.add(parserLine, SWAP, null);
+ b.add(parserLine, POP, null);
+ }
break;
}
case BANG: case BITNOT: case TYPEOF: {
break;
}
case NAME: {
- b.add(parserLine, TOPSCOPE);
- b.add(parserLine, LITERAL, JSString.intern(string));
- continueExprAfterAssignable(b,minPrecedence);
+ JS varKey = scopeKey(string);
+ if(varKey == null) {
+ b.add(parserLine, GLOBALSCOPE);
+ b.add(parserLine, LITERAL, JSString.intern(string));
+ }
+ continueExprAfterAssignable(b,minPrecedence,varKey);
+ break;
+ }
+ case CASCADE: {
+ if(peekToken() == ASSIGN) {
+ consume(ASSIGN);
+ startExpr(b, precedence[ASSIGN]);
+ b.add(parserLine, CASCADE, JS.T);
+ } else {
+ b.add(parserLine, CASCADE, JS.F);
+ }
break;
}
+
case FUNCTION: {
consume(LP);
int numArgs = 0;
b.add(parserLine, NEWFUNCTION, b2);
// function prelude; arguments array is already on the stack
- b2.add(parserLine, TOPSCOPE);
- b2.add(parserLine, SWAP);
- b2.add(parserLine, DECLARE, JSString.intern("arguments")); // declare arguments (equivalent to 'var arguments;')
- b2.add(parserLine, SWAP); // set this.arguments and leave the value on the stack
- b2.add(parserLine, PUT);
+ scopePush(b2);
+ scopeDeclare("arguments");
+ b2.add(parserLine, SCOPEPUT,scopeKey("arguments"));
while(peekToken() != RP) { // run through the list of argument names
numArgs++;
if (peekToken() == NAME) {
consume(NAME); // a named argument
- JS varName = JSString.intern(string);
b2.add(parserLine, DUP); // dup the args array
b2.add(parserLine, GET, JS.N(numArgs - 1)); // retrieve it from the arguments array
- b2.add(parserLine, TOPSCOPE);
- b2.add(parserLine, SWAP);
- b2.add(parserLine, DECLARE, varName); // declare the name
- b2.add(parserLine, SWAP);
- b2.add(parserLine, PUT);
- b2.add(parserLine, POP); // pop the value
- b2.add(parserLine, POP); // pop the scope
+ scopeDeclare(string);
+ b2.add(parserLine, SCOPEPUT, scopeKey(string));
+ b2.add(parserLine, POP);
}
if (peekToken() == RP) break;
consume(COMMA);
b2.numFormalArgs = numArgs;
b2.add(parserLine, POP); // pop off the arguments array
- b2.add(parserLine, POP); // pop off TOPSCOPE
if(peekToken() != LC)
throw pe("JSFunctions must have a block surrounded by curly brackets");
parseBlock(b2, null); // the function body
-
+
+ scopePop(b2);
b2.add(parserLine, LITERAL, null); // in case we "fall out the bottom", return NULL
b2.add(parserLine, RETURN);
* expression that modifies the assignable. This method always
* decreases the stack depth by exactly one element.
*/
- private void continueExprAfterAssignable(JSFunction b,int minPrecedence) throws IOException {
+ private void continueExprAfterAssignable(JSFunction b,int minPrecedence, JS varKey) throws IOException {
int saveParserLine = parserLine;
- _continueExprAfterAssignable(b,minPrecedence);
+ _continueExprAfterAssignable(b,minPrecedence,varKey);
parserLine = saveParserLine;
}
- private void _continueExprAfterAssignable(JSFunction b,int minPrecedence) throws IOException {
+ private void _continueExprAfterAssignable(JSFunction b,int minPrecedence, JS varKey) throws IOException {
if (b == null) throw new Error("got null b; this should never happen");
int tok = getToken();
if (minPrecedence != -1 && (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok])))
*/
case ASSIGN_BITOR: case ASSIGN_BITXOR: case ASSIGN_BITAND: case ASSIGN_LSH: case ASSIGN_RSH: case ASSIGN_URSH:
case ASSIGN_MUL: case ASSIGN_DIV: case ASSIGN_MOD: case ASSIGN_ADD: case ASSIGN_SUB: case ADD_TRAP: case DEL_TRAP: {
- if (tok != ADD_TRAP && tok != DEL_TRAP) b.add(parserLine, GET_PRESERVE);
+ if (tok != ADD_TRAP && tok != DEL_TRAP)
+ b.add(parserLine, varKey == null ? GET_PRESERVE : SCOPEGET, varKey);
startExpr(b, precedence[tok]);
if (tok != ADD_TRAP && tok != DEL_TRAP) {
// tok-1 is always s/^ASSIGN_// (0 is BITOR, 1 is ASSIGN_BITOR, etc)
b.add(parserLine, tok - 1, tok-1==ADD ? JS.N(2) : null);
- b.add(parserLine, PUT);
- b.add(parserLine, SWAP);
- b.add(parserLine, POP);
+ if(varKey == null) {
+ b.add(parserLine, PUT);
+ b.add(parserLine, SWAP);
+ b.add(parserLine, POP);
+ } else {
+ b.add(parserLine, SCOPEPUT, varKey);
+ }
} else {
+ if(varKey != null) throw pe("cannot place traps on local variables");
b.add(parserLine, tok);
}
break;
}
case INC: case DEC: { // postfix
- b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
- b.add(parserLine, LITERAL, JS.N(1));
- b.add(parserLine, tok == INC ? ADD : SUB, JS.N(2));
- b.add(parserLine, PUT, null);
- b.add(parserLine, SWAP, null);
- b.add(parserLine, POP, null);
- b.add(parserLine, LITERAL, JS.N(1));
- b.add(parserLine, tok == INC ? SUB : ADD, JS.N(2)); // undo what we just did, since this is postfix
+ if(varKey == null) {
+ b.add(parserLine, GET_PRESERVE, Boolean.TRUE);
+ b.add(parserLine, LITERAL, JS.N(1));
+ b.add(parserLine, tok == INC ? ADD : SUB, JS.N(2));
+ b.add(parserLine, PUT, null);
+ b.add(parserLine, SWAP, null);
+ b.add(parserLine, POP, null);
+ b.add(parserLine, LITERAL, JS.N(1));
+ b.add(parserLine, tok == INC ? SUB : ADD, JS.N(2)); // undo what we just did, since this is postfix
+ } else {
+ b.add(parserLine, SCOPEGET, varKey);
+ b.add(parserLine, DUP);
+ b.add(parserLine, LITERAL, JS.ONE);
+ b.add(parserLine, tok == INC ? ADD : SUB, JS.N(2));
+ b.add(parserLine, SCOPEPUT, varKey);
+ }
break;
}
case ASSIGN: {
startExpr(b, precedence[tok]);
- b.add(parserLine, PUT);
- b.add(parserLine, SWAP);
- b.add(parserLine, POP);
+ if(varKey == null) {
+ b.add(parserLine, PUT);
+ b.add(parserLine, SWAP);
+ b.add(parserLine, POP);
+ } else {
+ b.add(parserLine, SCOPEPUT, varKey);
+ }
break;
}
case LP: {
-
// Method calls are implemented by doing a GET_PRESERVE
// first. If the object supports method calls, it will
// return JS.METHOD
- b.add(parserLine, GET_PRESERVE);
+ b.add(parserLine, varKey == null ? GET_PRESERVE : SCOPEGET, varKey);
int n = parseArgs(b);
- b.add(parserLine, CALLMETHOD, JS.N(n));
+ b.add(parserLine, varKey == null ? CALLMETHOD : CALL, JS.N(n));
break;
}
default: {
pushBackToken();
- if(b.get(b.size-1) == LITERAL && b.getArg(b.size-1) != null)
+ if(varKey != null)
+ b.add(parserLine, SCOPEGET, varKey);
+ else if(b.get(b.size-1) == LITERAL && b.getArg(b.size-1) != null)
b.set(b.size-1,GET,b.getArg(b.size-1));
else
b.add(parserLine, GET);
consume(NAME);
}
b.add(parserLine, LITERAL, JSString.intern(string));
- continueExprAfterAssignable(b,minPrecedence);
+ continueExprAfterAssignable(b,minPrecedence,null);
break;
}
case LB: { // subscripting (not array constructor)
startExpr(b, -1);
consume(RB);
- continueExprAfterAssignable(b,minPrecedence);
+ continueExprAfterAssignable(b,minPrecedence,null);
break;
}
case HOOK: {
break;
}
case VAR: {
- b.add(parserLine, TOPSCOPE); // push the current scope
while(true) {
consume(NAME);
- b.add(parserLine, DECLARE, JSString.intern(string)); // declare it
+ String var = string;
+ scopeDeclare(var);
if (peekToken() == ASSIGN) { // if there is an '=' after the variable name
consume(ASSIGN);
startExpr(b, NO_COMMA);
- b.add(parserLine, PUT); // assign it
+ b.add(parserLine, SCOPEPUT, scopeKey(var)); // assign it
b.add(parserLine, POP); // clean the stack
- } else {
- b.add(parserLine, POP); // pop the string pushed by declare
- }
+ }
if (peekToken() != COMMA) break;
consume(COMMA);
}
- b.add(parserLine, POP); // pop off the topscope
if ((mostRecentlyReadToken != RC || peekToken() == SEMI) && peekToken() != -1 && mostRecentlyReadToken != SEMI) consume(SEMI);
break;
}
}
consume(RP);
// the exception is on top of the stack; put it to the chosen name
- b.add(parserLine, NEWSCOPE);
- b.add(parserLine, TOPSCOPE);
- b.add(parserLine, SWAP);
- b.add(parserLine, LITERAL,JSString.intern(exceptionVar));
- b.add(parserLine, DECLARE);
- b.add(parserLine, SWAP);
- b.add(parserLine, PUT);
- b.add(parserLine, POP);
+ scopePush(b);
+ scopeDeclare(exceptionVar);
+ b.add(parserLine, SCOPEPUT, scopeKey(exceptionVar));
b.add(parserLine, POP);
parseBlock(b, null);
- b.add(parserLine, OLDSCOPE);
+ scopePop(b);
b.add(parserLine, JMP);
catchEnds.addElement(new Integer(b.size-1));
b.add(parserLine,DUP);
b.add(parserLine,GET,JS.S("nextElement"));
- b.add(parserLine, NEWSCOPE);
+ scopePush(b);
- b.add(parserLine,TOPSCOPE);
- b.add(parserLine,SWAP);
- b.add(parserLine, hadVar ? DECLARE : LITERAL, JSString.intern(varName));
- b.add(parserLine,SWAP);
- b.add(parserLine,PUT);
- b.add(parserLine,POP);
- b.add(parserLine,POP);
- b.add(parserLine,SWAP);
+ if(hadVar) scopeDeclare(varName);
+ JS varKey = scopeKey(varName);
+
+ if(varKey == null) {
+ b.add(parserLine,GLOBALSCOPE);
+ b.add(parserLine,SWAP);
+ b.add(parserLine, LITERAL, JSString.intern(varName));
+ b.add(parserLine,SWAP);
+ b.add(parserLine,PUT);
+ b.add(parserLine,POP);
+ } else {
+ b.add(parserLine, SCOPEPUT, varKey);
+ }
+ b.add(parserLine,POP); // pop the put'ed value
+ b.add(parserLine,SWAP); // put CallMarker back into place
parseStatement(b, null);
- b.add(parserLine, OLDSCOPE);
+ scopePop(b);
b.add(parserLine, CONTINUE);
// jump here on break
b.set(size, JS.N(b.size - size));
b.add(parserLine, POP);
} else {
if (hadVar) pushBackToken(VAR, null); // yeah, this actually matters
- b.add(parserLine, NEWSCOPE); // grab a fresh scope
+ scopePush(b); // grab a fresh scope
parseStatement(b, null); // initializer
JSFunction e2 = // we need to put the incrementor before the test
b.add(parserLine, CONTINUE); // if we fall out the bottom, CONTINUE
b.set(size2 - 1, JS.N(b.size - size2 + 1)); // end of the loop
- b.add(parserLine, OLDSCOPE); // get our scope back
+ scopePop(b); // get our scope back
}
break;
}
case LC: { // blocks are statements too
pushBackToken();
- b.add(parserLine, NEWSCOPE);
+ scopePush(b);
parseBlock(b, label);
- b.add(parserLine, OLDSCOPE);
+ scopePop(b);
break;
}
projects / org.ibex.core.git / blobdiff