import org.xwt.util.*;
import java.io.*;
-/** Parses a stream of lexed tokens into a tree of ByteCodeBlock's */
+/** Parses a stream of lexed tokens into a tree of CompiledFunction's */
class Parser extends Lexer implements ByteCodes {
/** for debugging */
public static void main(String[] s) throws Exception {
- Parser p = new Parser(new InputStreamReader(System.in), "stdin", 0);
- while(true) {
- ByteCodeBlock block = new ByteCodeBlock(0, "stdin");
- p.parseStatement(false, block);
- if (block == null) return;
- System.out.println(block);
- if (p.peekToken() == -1) return;
- }
+ CompiledFunction block = new CompiledFunction("stdin", 0, new InputStreamReader(System.in), null);
+ if (block == null) return;
+ System.out.println(block);
}
// Parsing Logic /////////////////////////////////////////////////////////
- private ByteCodeBlock newbb(int line) { return new ByteCodeBlock(line, sourceName); }
+ /** the label for the current statement */
+ private String label = null;
/** gets a token and throws an exception if it is not <tt>code</tt> */
public void consume(int code) throws IOException {
}
/** append the largest expression beginning with prefix containing no operators of precedence below <tt>minPrecedence</tt> */
- public void startExpr(ByteCodeBlock block) throws IOException { startExpr(-1, block); }
+ public void startExpr(CompiledFunction block) throws IOException { startExpr(-1, block); }
/*
- public ByteCodeBlock startExpr(int minPrecedence) throws IOException {
- ByteCodeBlock ret = new ByteCodeBlock(line, sourceName);
+ public CompiledFunction startExpr(int minPrecedence) throws IOException {
+ CompiledFunction ret = new CompiledFunction(line, sourceName);
startExpr(minPrecedence, ret);
return ret.size() == 0 ? null : ret;
}
*/
- public void startExpr(int minPrecedence, ByteCodeBlock appendTo) throws IOException {
+ public void startExpr(int minPrecedence, CompiledFunction appendTo) throws IOException {
int tok = getToken();
- int curLine = line;
- if (tok == -1) return;
-
- ByteCodeBlock b = appendTo;
-
+ int line = this.line;
+ CompiledFunction b = appendTo;
switch (tok) {
- case NUMBER: continueExpr(b.add(ByteCodeBlock.LITERAL, number), minPrecedence); return;
- case STRING: continueExpr(b.add(ByteCodeBlock.LITERAL, string), minPrecedence); return;
- case THIS: continueExpr(b.add(TOPSCOPE, null), minPrecedence); return;
- case NULL: continueExpr(b.add(ByteCodeBlock.LITERAL, null), minPrecedence); return;
- case TRUE: case FALSE: continueExpr(b.add(ByteCodeBlock.LITERAL, new Boolean(tok == TRUE)), minPrecedence); return;
+ case -1: return;
+ case NUMBER: continueExpr(b.add(line, CompiledFunction.LITERAL, number), minPrecedence); return;
+ case STRING: continueExpr(b.add(line, CompiledFunction.LITERAL, string), minPrecedence); return;
+ case THIS: continueExpr(b.add(line, TOPSCOPE, null), minPrecedence); return;
+ case NULL: continueExpr(b.add(line, CompiledFunction.LITERAL, null), minPrecedence); return;
+ case TRUE: case FALSE: continueExpr(b.add(line, CompiledFunction.LITERAL, new Boolean(tok == TRUE)), minPrecedence); return;
case LB: {
- b.add(ARRAY, new Integer(0));
+ b.add(line, ARRAY, new Integer(0));
int i = 0;
while(true) {
int size = b.size();
startExpr(b);
if (size == b.size())
if (peekToken() == RB) { consume(RB); continueExpr(b, minPrecedence); return; }
- b.add(LITERAL, new Integer(i++));
- if (size == b.size()) b.add(LITERAL, null);
- b.add(PUT);
- b.add(POP);
+ b.add(line, LITERAL, new Integer(i++));
+ if (size == b.size()) b.add(line, LITERAL, null);
+ b.add(line, PUT);
+ b.add(line, POP);
if (peekToken() == RB) { consume(RB); continueExpr(b, minPrecedence); return; }
consume(COMMA);
}
}
case SUB: {
consume(NUMBER);
- b.add(ByteCodeBlock.LITERAL, new Double(number.doubleValue() * -1));
+ b.add(line, CompiledFunction.LITERAL, new Double(number.doubleValue() * -1));
continueExpr(b, minPrecedence);
return;
}
}
case BANG: case BITNOT: case TYPEOF: {
startExpr(precedence[tok], b);
- b.add(tok);
+ b.add(line, tok);
continueExpr(b, minPrecedence);
return;
}
case LC: {
- b.add(OBJECT, null);
+ b.add(line, OBJECT, null);
if (peekToken() != RC) while(true) {
if (peekToken() != NAME && peekToken() != STRING) throw new Error("expected NAME or STRING");
getToken();
- b.add(LITERAL, string);
+ b.add(line, LITERAL, string);
consume(COLON);
startExpr(b);
- b.add(PUT);
- b.add(POP);
+ b.add(line, PUT);
+ b.add(line, POP);
if (peekToken() == RC) break;
consume(COMMA);
if (peekToken() == RC) break;
String name = string;
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- b.add(TOPSCOPE);
- b.add(ByteCodeBlock.LITERAL, name);
+ b.add(line, TOPSCOPE);
+ b.add(line, CompiledFunction.LITERAL, name);
startExpr(minPrecedence, b);
- b.add(ByteCodeBlock.PUT);
- b.add(ByteCodeBlock.SWAP);
- b.add(ByteCodeBlock.POP);
+ b.add(line, CompiledFunction.PUT);
+ b.add(line, CompiledFunction.SWAP);
+ b.add(line, CompiledFunction.POP);
} else {
- b.add(TOPSCOPE);
- b.add(ByteCodeBlock.LITERAL, name);
- b.add(ByteCodeBlock.GET);
+ b.add(line, TOPSCOPE);
+ b.add(line, CompiledFunction.LITERAL, name);
+ b.add(line, CompiledFunction.GET);
}
continueExpr(b, minPrecedence);
return;
case FUNCTION: {
consume(LP);
int numArgs = 0;
- ByteCodeBlock b2 = newbb(curLine);
- b2.add(TOPSCOPE);
- b2.add(SWAP);
- b2.add(LITERAL, "arguments");
- b2.add(LITERAL, "arguments");
- b2.add(DECLARE);
- b2.add(SWAP);
- b2.add(PUT);
- b2.add(SWAP);
- b2.add(POP);
+ CompiledFunction b2 = new CompiledFunction(sourceName, line, null);
+ b2.add(line, TOPSCOPE);
+ b2.add(line, SWAP);
+ b2.add(line, LITERAL, "arguments");
+ b2.add(line, LITERAL, "arguments");
+ b2.add(line, DECLARE);
+ b2.add(line, SWAP);
+ b2.add(line, PUT);
+ b2.add(line, SWAP);
+ b2.add(line, POP);
if (peekToken() == RP) consume(RP);
else while(true) {
if (peekToken() == COMMA) {
consume(NAME);
// declare the name
- b2.add(LITERAL, string);
- b2.add(DECLARE);
+ b2.add(line, LITERAL, string);
+ b2.add(line, DECLARE);
// retrieve it from the arguments array
- b2.add(LITERAL, new Integer(numArgs));
- b2.add(GET_PRESERVE);
- b2.add(SWAP);
- b2.add(POP);
+ b2.add(line, LITERAL, new Integer(numArgs));
+ b2.add(line, GET_PRESERVE);
+ b2.add(line, SWAP);
+ b2.add(line, POP);
// put it to the current scope
- b2.add(TOPSCOPE);
- b2.add(SWAP);
- b2.add(LITERAL, string);
- b2.add(SWAP);
- b2.add(PUT);
+ b2.add(line, TOPSCOPE);
+ b2.add(line, SWAP);
+ b2.add(line, LITERAL, string);
+ b2.add(line, SWAP);
+ b2.add(line, PUT);
// clean the stack
- b2.add(POP);
- b2.add(POP);
+ b2.add(line, POP);
+ b2.add(line, POP);
if (peekToken() == RP) { consume(RP); break; }
consume(COMMA);
numArgs++;
}
// pop off the arguments array
- b2.add(POP);
+ b2.add(line, POP);
parseStatement(true, b2);
- b2.add(LITERAL, null);
- b2.add(RETURN);
- continueExpr(b.add(NEWFUNCTION, b2), minPrecedence);
+ b2.add(line, LITERAL, null);
+ b2.add(line, RETURN);
+ continueExpr(b.add(line, NEWFUNCTION, b2), minPrecedence);
return;
}
default: pushBackToken(); return;
}
}
- public void continueExpr(ByteCodeBlock prefix, int minPrecedence) throws IOException {
+ public void continueExpr(CompiledFunction prefix, int minPrecedence) throws IOException {
int tok = getToken();
- int curLine = line;
if (tok == -1) return;
if (minPrecedence > 0 && precedence[tok] != 0)
if (precedence[tok] < minPrecedence || (precedence[tok] == minPrecedence && !isRightAssociative[tok]))
{ pushBackToken(); return; }
-
if (prefix == null) throw new Error("got null prefix");
- ByteCodeBlock b = prefix;
+ CompiledFunction b = prefix;
switch (tok) {
case ASSIGN_ADD: case ASSIGN_SUB: case ASSIGN_MUL: case ASSIGN_DIV: case ASSIGN_MOD: {
prefix.set(prefix.size() - 1, b.GET_PRESERVE, new Boolean(true));
startExpr(precedence[tok - 1], b);
- prefix.add(tok - 1);
- prefix.add(PUT);
- prefix.add(SWAP);
- prefix.add(POP);
+ prefix.add(line, tok - 1);
+ prefix.add(line, PUT);
+ prefix.add(line, SWAP);
+ prefix.add(line, POP);
continueExpr(b, minPrecedence);
return;
}
consume(COMMA);
}
consume(RP);
- b.add(CALL, new Integer(i));
+ b.add(line, CALL, new Integer(i));
continueExpr(b, minPrecedence);
return;
}
case RSH: case URSH: case ADD: case MUL: case DIV: case MOD:
case GT: case GE: case EQ: case NE: case LT: case LE: case SUB: {
startExpr(precedence[tok], b);
- b.add(tok);
+ b.add(line, tok);
continueExpr(b, minPrecedence);
return;
}
case OR: case AND: {
- b.add(tok == AND ? b.JF : b.JT, new Integer(0));
+ b.add(line, tok == AND ? b.JF : b.JT, new Integer(0));
int size = b.size();
startExpr(precedence[tok], b);
b.set(size - 1, new Integer(b.size() - size + 2));
- b.add(JMP, new Integer(2));
- b.add(LITERAL, tok == AND ? new Boolean(false) : new Boolean(true));
+ b.add(line, JMP, new Integer(2));
+ b.add(line, LITERAL, tok == AND ? new Boolean(false) : new Boolean(true));
continueExpr(b, minPrecedence);
return;
}
String target = string;
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- b.add(LITERAL, target);
+ b.add(line, LITERAL, target);
startExpr(b);
- b.add(PUT);
- b.add(SWAP);
- b.add(POP);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
} else {
- b.add(LITERAL, target);
- b.add(GET);
+ b.add(line, LITERAL, target);
+ b.add(line, GET);
}
continueExpr(b, minPrecedence);
return;
if (peekToken() == ASSIGN) {
consume(ASSIGN);
startExpr(b);
- b.add(PUT);
- b.add(SWAP);
- b.add(POP);
+ b.add(line, PUT);
+ b.add(line, SWAP);
+ b.add(line, POP);
} else {
- b.add(GET);
+ b.add(line, GET);
}
continueExpr(b, minPrecedence);
return;
}
case HOOK: {
- b.add(JF, new Integer(0));
+ b.add(line, JF, new Integer(0));
int size = b.size();
startExpr(b);
b.set(size - 1, new Integer(b.size() - size + 2));
- b.add(JMP, new Integer(0));
+ b.add(line, JMP, new Integer(0));
consume(COLON);
size = b.size();
startExpr(b);
}
}
- /** a block is either a single statement or a list of statements surrounded by curly braces; all expressions are also statements */
-
- public ByteCodeBlock parseStatement() throws IOException {
- ByteCodeBlock ret = new ByteCodeBlock(line, sourceName);
- ret.add(ret.LITERAL, null);
+ /**
+ * a block is either a single statement or a list of statements surrounded by curly braces;
+ * all expressions are also statements
+ */
+ public CompiledFunction parseStatement() throws IOException {
+ CompiledFunction ret = new CompiledFunction(sourceName, line, null);
+ ret.add(line, ret.LITERAL, null);
parseStatement(false, ret);
if (ret.size() == 1) return null;
return ret;
}
- public void parseStatement(boolean requireBraces, ByteCodeBlock b) throws IOException {
+ public void parseStatement(boolean requireBraces, CompiledFunction b) throws IOException {
int tok = peekToken();
if (tok == -1) return;
+ int line = this.line;
boolean braced = tok == LC;
if (requireBraces && !braced) throw new ParserException("expected {, got " + codeToString[tok]);
if (braced) consume(LC);
- int curLine = line;
while(true) {
switch(tok = peekToken()) {
case THROW: case RETURN: case ASSERT: {
getToken();
- if (tok == RETURN && peekToken() == SEMI) b.add(LITERAL, null);
+ if (tok == RETURN && peekToken() == SEMI) b.add(line, LITERAL, null);
else startExpr(b);
consume(SEMI);
- b.add(tok);
+ b.add(line, tok);
break;
}
case BREAK: case CONTINUE: {
getToken();
if (peekToken() == NAME) consume(NAME);
- b.add(tok, string);
+ b.add(line, tok, string);
consume(SEMI);
break;
}
- case SEMI:
+ case SEMI: {
consume(SEMI);
if (!braced) return;
break;
+ }
case VAR: {
consume(VAR);
- b.add(TOPSCOPE); // push the current scope
+ b.add(line, TOPSCOPE); // push the current scope
while(true) {
consume(NAME);
String name = string;
- b.add(LITERAL, name); // push the name to be declared
- b.add(DECLARE); // declare it
+ b.add(line, LITERAL, name); // push the name to be declared
+ b.add(line, DECLARE); // declare it
if (peekToken() == ASSIGN) { // if there is an '=' after the variable name
- b.add(LITERAL, name); // put the var name back on the stack
+ b.add(line, LITERAL, name); // put the var name back on the stack
consume(ASSIGN);
startExpr(b);
- b.add(PUT);
- b.add(POP);
+ b.add(line, PUT);
+ b.add(line, POP);
}
if (peekToken() != COMMA) break;
consume(COMMA);
}
- b.add(POP);
+ b.add(line, POP);
if (peekToken() == SEMI) consume(SEMI);
break;
}
startExpr(b);
consume(RP);
- b.add(JF, new Integer(0));
+ b.add(line, JF, new Integer(0));
int size = b.size();
parseStatement(false, b);
if (peekToken() == ELSE) {
consume(ELSE);
b.set(size - 1, new Integer(2 + b.size() - size));
- b.add(JMP, new Integer(0));
+ b.add(line, JMP, new Integer(0));
size = b.size();
parseStatement(false, b);
}
case WHILE: {
consume(WHILE);
consume(LP);
- b.add(LOOP);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
int size = b.size();
- b.add(POP);
+ b.add(line, POP);
startExpr(b);
- b.add(JT, new Integer(2));
- b.add(BREAK);
+ b.add(line, JT, new Integer(2));
+ b.add(line, BREAK);
consume(RP);
parseStatement(false, b);
- b.add(CONTINUE); // if we fall out of the end, definately continue
+ b.add(line, CONTINUE); // if we fall out of the end, definately continue
b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop
break;
}
case SWITCH: {
consume(SWITCH);
consume(LP);
- b.add(LOOP);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
int size0 = b.size();
startExpr(b);
consume(RP);
while(true)
if (peekToken() == CASE) {
consume(CASE);
- b.add(DUP);
+ b.add(line, DUP);
startExpr(b);
consume(COLON);
- b.add(EQ);
- b.add(JF, new Integer(0));
+ b.add(line, EQ);
+ b.add(line, JF, new Integer(0));
int size = b.size();
while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) {
int size2 = b.size();
}
} else if (peekToken() == RC) {
consume(RC);
- b.add(BREAK);
+ b.add(line, BREAK);
break;
} else {
throw new ParserException("expected CASE, DEFAULT, or RC; got " + codeToString[peekToken()]);
}
- b.add(BREAK);
+ b.add(line, BREAK);
b.set(size0 - 1, new Integer(b.size() - size0 + 1)); // end of the loop
break;
}
case DO: {
consume(DO);
- b.add(LOOP);
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
int size = b.size();
parseStatement(false, b);
consume(WHILE);
consume(LP);
startExpr(b);
- b.add(JT, new Integer(2));
- b.add(BREAK);
- b.add(CONTINUE);
+ b.add(line, JT, new Integer(2));
+ b.add(line, BREAK);
+ b.add(line, CONTINUE);
consume(RP);
consume(SEMI);
b.set(size - 1, new Integer(b.size() - size + 1)); // end of the loop
case TRY: {
// We deliberately allow you to omit braces in catch{}/finally{} if they are single statements...
consume(TRY);
+ b.add(line, TRY);
+ int size = b.size();
parseStatement(true, b);
+ b.add(line, POP); // pop the TryMarker
+ b.add(line, JMP); // jump forward to the end of the catch block
+ int size2 = b.size();
+ b.set(size - 1, new Integer(b.size() - size + 1));// the TRY argument points at the start of the CATCH block
if (peekToken() == CATCH) {
getToken();
consume(LP);
consume(NAME);
consume(RP);
- parseStatement(); // just discard the catchblock
+ // FIXME, we need an extra scope here
+ b.add(line, TOPSCOPE); // the exception is on top of the stack; put it to the variable
+ b.add(line, SWAP);
+ b.add(line, LITERAL);
+ b.add(line, SWAP);
+ b.add(line, PUT);
+ b.add(line, POP);
+ b.add(line, POP);
+ parseStatement(false, b);
}
+ b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // jump here if no exception was thrown
+
+ // FIXME: not implemented correctly
if (peekToken() == FINALLY) {
consume(FINALLY);
parseStatement(false, b);
break;
}
- case FOR: {
- consume(FOR);
- consume(LP);
-
- tok = getToken();
- boolean hadVar = false;
- if (tok == VAR) { hadVar = true; tok = getToken(); }
- String varName = string;
- boolean forIn = peekToken() == IN;
- pushBackToken(tok, varName);
-
- if (forIn) {
- // FIXME: break needs to work in here
- consume(NAME);
- consume(IN);
- startExpr(b);
- b.add(PUSHKEYS);
- b.add(LITERAL, "length");
- b.add(GET);
- consume(RP);
- ByteCodeBlock b2 = newbb(curLine);
-
- b.add(PUSHSCOPE);
-
- b.add(LITERAL, new Integer(1));
- b.add(SUB);
- b.add(DUP);
- b.add(LITERAL, new Integer(0));
- b.add(LT);
- b.add(JT, new Integer(7));
- b.add(GET_PRESERVE);
- b.add(LITERAL, varName);
- b.add(LITERAL, varName);
- b.add(DECLARE);
- b.add(PUT);
- parseStatement(false, b);
-
- b.add(POPSCOPE);
-
- break;
+ case FOR: {
+ consume(FOR);
+ consume(LP);
- } else {
- if (hadVar) pushBackToken(VAR, null);
- b.add(PUSHSCOPE);
-
- parseStatement(false, b);
- ByteCodeBlock e2 = new ByteCodeBlock(line, sourceName);
- startExpr(e2);
- consume(SEMI);
- if (e2 == null) e2 = newbb(curLine).add(b.LITERAL, Boolean.TRUE);
-
- b.add(LOOP);
- int size2 = b.size();
-
- b.add(JT, new Integer(0));
- int size = b.size();
- startExpr(b);
- if (b.size() > size) b.add(POP);
- b.set(size - 1, new Integer(b.size() - size + 1));
- consume(RP);
-
- b.paste(e2);
- b.add(JT, new Integer(2));
- b.add(BREAK);
- parseStatement(false, b);
- b.add(CONTINUE);
- b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // end of the loop
-
- b.add(POPSCOPE);
- break;
+ tok = getToken();
+ boolean hadVar = false;
+ if (tok == VAR) { hadVar = true; tok = getToken(); }
+ String varName = string;
+ boolean forIn = peekToken() == IN;
+ pushBackToken(tok, varName);
+
+ if (forIn) {
+ // FIXME: break needs to work in here
+ consume(NAME);
+ consume(IN);
+ startExpr(b);
+ b.add(line, PUSHKEYS);
+ b.add(line, LITERAL, "length");
+ b.add(line, GET);
+ consume(RP);
+ CompiledFunction b2 = new CompiledFunction(sourceName, line, null);
+
+ b.add(line, NEWSCOPE);
+
+ b.add(line, LITERAL, new Integer(1));
+ b.add(line, SUB);
+ b.add(line, DUP);
+ b.add(line, LITERAL, new Integer(0));
+ b.add(line, LT);
+ b.add(line, JT, new Integer(7));
+ b.add(line, GET_PRESERVE);
+ b.add(line, LITERAL, varName);
+ b.add(line, LITERAL, varName);
+ b.add(line, DECLARE);
+ b.add(line, PUT);
+ parseStatement(false, b);
+
+ b.add(line, OLDSCOPE);
+
+ break;
+
+ } else {
+ if (hadVar) pushBackToken(VAR, null);
+ b.add(line, NEWSCOPE);
+
+ parseStatement(false, b);
+ CompiledFunction e2 = new CompiledFunction(sourceName, line, null);
+ startExpr(e2);
+ consume(SEMI);
+ if (e2 == null) e2 = new CompiledFunction(sourceName, line, null).add(line, b.LITERAL, Boolean.TRUE);
+
+ if (label != null) b.add(line, LABEL, label);
+ b.add(line, LOOP);
+ int size2 = b.size();
+
+ b.add(line, JT, new Integer(0));
+ int size = b.size();
+ startExpr(b);
+ if (b.size() > size) b.add(line, POP);
+ b.set(size - 1, new Integer(b.size() - size + 1));
+ consume(RP);
+
+ b.paste(e2);
+ b.add(line, JT, new Integer(2));
+ b.add(line, BREAK);
+ parseStatement(false, b);
+ b.add(line, CONTINUE);
+ b.set(size2 - 1, new Integer(b.size() - size2 + 1)); // end of the loop
+
+ b.add(line, OLDSCOPE);
+ break;
+ }
}
- }
-
+
case NAME: {
consume(NAME);
- String name = string;
+ String oldlabel = label;
+ label = string;
if (peekToken() == COLON) {
consume(COLON);
- b.add(ByteCodeBlock.LABEL, string);
+ parseStatement(false, b);
+ label = oldlabel;
break;
} else {
- pushBackToken(NAME, name);
+ pushBackToken(NAME, label);
+ label = oldlabel;
// fall through to default case
}
}
int size = b.size();
startExpr(b);
if (size == b.size()) return;
- b.add(POP);
+ b.add(line, POP);
if (peekToken() == SEMI) consume(SEMI);
break;
}
}
}
- class ParserException extends RuntimeException {
+ private class ParserException extends RuntimeException {
public ParserException(String s) { super(sourceName + ":" + line + " " + s); }
}
projects / org.ibex.core.git / blobdiff