X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FParser.java;h=cf0fdec290b273842ca08717efd3c06daa1144f1;hb=f0fc6aa0b5ff2539e0f307cd0e592976ac9e7ac7;hp=c3f90ca3955ac66e5058e4db46f1c6fc74544f28;hpb=00a29178bac1ee7725928dc5c7022babf6b454f4;p=org.ibex.core.git diff --git a/src/org/xwt/js/Parser.java b/src/org/xwt/js/Parser.java index c3f90ca..cf0fdec 100644 --- a/src/org/xwt/js/Parser.java +++ b/src/org/xwt/js/Parser.java @@ -83,6 +83,8 @@ class Parser extends Lexer implements ByteCodes { static byte[] precedence = new byte[MAX_TOKEN + 1]; static boolean[] isRightAssociative = new boolean[MAX_TOKEN + 1]; + // Use this as the precedence when we want anything up to the comma + private final static int NO_COMMA = 2; static { isRightAssociative[ASSIGN] = isRightAssociative[ASSIGN_BITOR] = @@ -97,6 +99,8 @@ class Parser extends Lexer implements ByteCodes { isRightAssociative[ASSIGN_DIV] = isRightAssociative[ASSIGN_MOD] = true; + precedence[COMMA] = 1; + // 2 is intentionally left unassigned. we use minPrecedence==2 for comma separated lists precedence[ASSIGN] = precedence[ASSIGN_BITOR] = precedence[ASSIGN_BITXOR] = @@ -108,24 +112,20 @@ class Parser extends Lexer implements ByteCodes { precedence[ASSIGN_SUB] = precedence[ASSIGN_MUL] = precedence[ASSIGN_DIV] = - precedence[ASSIGN_MOD] = 1; - precedence[HOOK] = 2; - precedence[COMMA] = 3; - precedence[OR] = precedence[AND] = 4; - precedence[GT] = precedence[GE] = 5; - precedence[BITOR] = 6; - precedence[BITXOR] = 7; - precedence[BITAND] = 8; - precedence[EQ] = precedence[NE] = 9; - precedence[LT] = precedence[LE] = 10; - precedence[SHEQ] = precedence[SHNE] = 11; + precedence[ASSIGN_MOD] = 3; + precedence[HOOK] = 4; + precedence[OR] = 5; + precedence[AND] = 6; + precedence[BITOR] = 7; + precedence[BITXOR] = 8; + precedence[BITAND] = 9; + precedence[EQ] = precedence[NE] = precedence[SHEQ] = precedence[SHNE] = 10; + precedence[LT] = precedence[LE] = precedence[GT] = precedence[GE] = 11; precedence[LSH] = precedence[RSH] = precedence[URSH] = 12; - precedence[ADD] = precedence[SUB] = 13; - precedence[MUL] = precedence[DIV] = precedence[MOD] = 14; - precedence[BITNOT] = 15; - precedence[INC] = precedence[DEC] = 16; - precedence[LP] = 17; - precedence[DOT] = precedence[LB] = 18; + precedence[ADD] = precedence[SUB] = 12; + precedence[MUL] = precedence[DIV] = precedence[MOD] = 13; + precedence[BITNOT] = precedence[BANG] = precedence[TYPEOF] = 14; + precedence[DOT] = precedence[LB] = precedence[LP] = precedence[INC] = precedence[DEC] = 15; } @@ -133,7 +133,7 @@ class Parser extends Lexer implements ByteCodes { /** gets a token and throws an exception if it is not code */ private void consume(int code) throws IOException { - if (getToken() != code) throw new ParserException("expected " + codeToString[code] + ", got " + (op == -1 ? "EOF" : codeToString[op])); + if (getToken() != code) throw pe("expected " + codeToString[code] + ", got " + (op == -1 ? "EOF" : codeToString[op])); } /** @@ -152,7 +152,7 @@ class Parser extends Lexer implements ByteCodes { CompiledFunctionImpl b = appendTo; switch (tok) { - case -1: throw new ParserException("expected expression"); + case -1: throw pe("expected expression"); // all of these simply push values onto the stack case NUMBER: b.add(parserLine, LITERAL, number); break; @@ -168,11 +168,11 @@ class Parser extends Lexer implements ByteCodes { if (peekToken() != RB) while(true) { // iterate over the initialization values int size = b.size(); + b.add(parserLine, LITERAL, new Integer(i++)); // push the index in the array to place it into if (peekToken() == COMMA || peekToken() == RB) b.add(parserLine, LITERAL, null); // for stuff like [1,,2,] else - startExpr(b, -1); // push the value onto the stack - b.add(parserLine, LITERAL, new Integer(i++)); // push the index in the array to place it into + startExpr(b, NO_COMMA); // push the value onto the stack b.add(parserLine, PUT); // put it into the array b.add(parserLine, POP); // discard the value remaining on the stack if (peekToken() == RB) break; @@ -194,9 +194,14 @@ class Parser extends Lexer implements ByteCodes { } case INC: case DEC: { // prefix (not postfix) startExpr(b, precedence[tok]); - if (b.get(b.size() - 1) != GET) - throw new ParserException("prefixed increment/decrement can only be performed on a valid assignment target"); - b.set(b.size() - 1, tok, new Boolean(true)); + int prev = b.size() - 1; + 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 + throw pe("prefixed increment/decrement can only be performed on a valid assignment target"); + b.add(parserLine, tok, Boolean.TRUE); break; } case BANG: case BITNOT: case TYPEOF: { @@ -209,11 +214,11 @@ class Parser extends Lexer implements ByteCodes { if (peekToken() != RC) while(true) { if (peekToken() != NAME && peekToken() != STRING) - throw new ParserException("expected NAME or STRING"); + throw pe("expected NAME or STRING"); getToken(); b.add(parserLine, LITERAL, string); // grab the key consume(COLON); - startExpr(b, -1); // grab the value + startExpr(b, NO_COMMA); // grab the value b.add(parserLine, PUT); // put the value into the object b.add(parserLine, POP); // discard the remaining value if (peekToken() == RC) break; @@ -226,7 +231,7 @@ class Parser extends Lexer implements ByteCodes { case NAME: { b.add(parserLine, TOPSCOPE); b.add(parserLine, LITERAL, string); - continueExprAfterAssignable(b); + continueExprAfterAssignable(b,minPrecedence); break; } case FUNCTION: { @@ -236,38 +241,26 @@ class Parser extends Lexer implements ByteCodes { b.add(parserLine, NEWFUNCTION, b2); // function prelude; arguments array is already on the stack - b2.add(parserLine, TOPSCOPE); // push the scope onto the stack - b2.add(parserLine, SWAP); // swap 'this' and 'arguments' - - b2.add(parserLine, LITERAL, "arguments"); // declare arguments (equivalent to 'var arguments;') - b2.add(parserLine, DECLARE); - - b2.add(parserLine, LITERAL, "arguments"); // set this.arguments and leave the value on the stack + b2.add(parserLine, TOPSCOPE); b2.add(parserLine, SWAP); + b2.add(parserLine, DECLARE, "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); - b2.add(parserLine, SWAP); - b2.add(parserLine, POP); while(peekToken() != RP) { // run through the list of argument names if (peekToken() == NAME) { consume(NAME); // a named argument + String varName = string; - b2.add(parserLine, LITERAL, string); // declare the name - b2.add(parserLine, DECLARE); - - b2.add(parserLine, LITERAL, new Integer(numArgs)); // retrieve it from the arguments array - b2.add(parserLine, GET_PRESERVE); + b2.add(parserLine, DUP); // dup the args array + b2.add(parserLine, GET, new Integer(numArgs)); // retrieve it from the arguments array + b2.add(parserLine, TOPSCOPE); b2.add(parserLine, SWAP); - b2.add(parserLine, POP); - - b2.add(parserLine, TOPSCOPE); // put it to the current scope - b2.add(parserLine, SWAP); - b2.add(parserLine, LITERAL, string); + b2.add(parserLine, DECLARE, varName); // declare the name b2.add(parserLine, SWAP); - b2.add(parserLine, PUT); - - b2.add(parserLine, POP); // clean the stack - b2.add(parserLine, POP); + b2.add(parserLine, PUT); + b2.add(parserLine, POP); // pop the value + b2.add(parserLine, POP); // pop the scope } if (peekToken() == RP) break; consume(COMMA); @@ -276,15 +269,19 @@ class Parser extends Lexer implements ByteCodes { consume(RP); b2.add(parserLine, POP); // pop off the arguments array + b2.add(parserLine, POP); // pop off TOPSCOPE + + if(peekToken() != LC) + throw pe("Functions must have a block surrounded by curly brackets"); + + parseBlock(b2, null); // the function body - parseStatement(b2, null); // the function body - - b2.add(parserLine, LITERAL, null); // in case we "fall out the bottom", return NULL + b2.add(parserLine, LITERAL, null); // in case we "fall out the bottom", return NULL b2.add(parserLine, RETURN); break; } - default: throw new ParserException("expected expression, found " + codeToString[tok] + ", which cannot start an expression"); + default: throw pe("expected expression, found " + codeToString[tok] + ", which cannot start an expression"); } // attempt to continue the expression @@ -299,46 +296,51 @@ class Parser extends Lexer implements ByteCodes { * expression that modifies the assignable. This method always * decreases the stack depth by exactly one element. */ - private void continueExprAfterAssignable(CompiledFunctionImpl b) throws IOException { + private void continueExprAfterAssignable(CompiledFunctionImpl b,int minPrecedence) throws IOException { int saveParserLine = parserLine; - _continueExprAfterAssignable(b); + _continueExprAfterAssignable(b,minPrecedence); parserLine = saveParserLine; } - private void _continueExprAfterAssignable(CompiledFunctionImpl b) throws IOException { + private void _continueExprAfterAssignable(CompiledFunctionImpl b,int minPrecedence) 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]))) + // force the default case + tok = -1; switch(tok) { case ASSIGN_BITOR: case ASSIGN_BITXOR: case ASSIGN_BITAND: case ASSIGN_LSH: case ASSIGN_RSH: case ASSIGN_URSH: case ASSIGN_ADD: case ASSIGN_SUB: case ASSIGN_MUL: case ASSIGN_DIV: case ASSIGN_MOD: { b.add(parserLine, GET_PRESERVE); - startExpr(b, -1); - b.add(parserLine, tok - 1); + startExpr(b, precedence[tok]); + // tok-1 is always s/^ASSIGN_// (0 is BITOR, 1 is ASSIGN_BITOR, etc) + b.add(parserLine, tok - 1, tok-1==ADD ? new Integer(2) : null); b.add(parserLine, PUT); b.add(parserLine, SWAP); b.add(parserLine, POP); break; } case INC: case DEC: { // postfix - b.add(parserLine, GET_PRESERVE); - b.add(parserLine, LITERAL, new Integer(1)); - b.add(parserLine, tok == INC ? ADD : SUB); - b.add(parserLine, PUT); - b.add(parserLine, SWAP); - b.add(parserLine, POP); - b.add(parserLine, LITERAL, new Integer(1)); - b.add(parserLine, tok == INC ? SUB : ADD); + b.add(parserLine, tok, Boolean.FALSE); break; } case ASSIGN: { - startExpr(b, -1); + startExpr(b, precedence[tok]); b.add(parserLine, PUT); b.add(parserLine, SWAP); b.add(parserLine, POP); break; } + case LP: { + int n = parseArgs(b); + b.add(parserLine,CALLMETHOD,new Integer(n)); + break; + } default: { pushBackToken(); - b.add(parserLine, GET); + 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); return; } } @@ -372,26 +374,29 @@ class Parser extends Lexer implements ByteCodes { switch (tok) { case LP: { // invocation (not grouping) - int i = 0; - while(peekToken() != RP) { - i++; - if (peekToken() != COMMA) { - startExpr(b, -1); - if (peekToken() == RP) break; - } - consume(COMMA); - } - consume(RP); - b.add(parserLine, CALL, new Integer(i)); + int n = parseArgs(b); + b.add(parserLine, CALL, new Integer(n)); break; } case BITOR: case BITXOR: case BITAND: case SHEQ: case SHNE: case LSH: - case RSH: case URSH: case ADD: case MUL: case DIV: case MOD: + case RSH: case URSH: case MUL: case DIV: case MOD: case GT: case GE: case EQ: case NE: case LT: case LE: case SUB: { startExpr(b, precedence[tok]); b.add(parserLine, tok); break; } + case ADD: { + int count=1; + int nextTok; + do { + startExpr(b,precedence[tok]); + count++; + nextTok = getToken(); + } while(nextTok == tok); + pushBackToken(); + b.add(parserLine, tok, new Integer(count)); + break; + } case OR: case AND: { b.add(parserLine, tok == AND ? b.JF : b.JT, new Integer(0)); // test to see if we can short-circuit int size = b.size(); @@ -405,27 +410,33 @@ class Parser extends Lexer implements ByteCodes { case DOT: { consume(NAME); b.add(parserLine, LITERAL, string); - continueExprAfterAssignable(b); + continueExprAfterAssignable(b,minPrecedence); break; } case LB: { // subscripting (not array constructor) startExpr(b, -1); consume(RB); - continueExprAfterAssignable(b); + continueExprAfterAssignable(b,minPrecedence); break; } case HOOK: { b.add(parserLine, JF, new Integer(0)); // jump to the if-false expression int size = b.size(); - startExpr(b, -1); // write the if-true expression + startExpr(b, minPrecedence); // write the if-true expression b.add(parserLine, JMP, new Integer(0)); // if true, jump *over* the if-false expression b.set(size - 1, new Integer(b.size() - size + 1)); // now we know where the target of the jump is consume(COLON); size = b.size(); - startExpr(b, -1); // write the if-false expression + startExpr(b, minPrecedence); // write the if-false expression b.set(size - 1, new Integer(b.size() - size + 1)); // this is the end; jump to here break; } + case COMMA: { + // pop the result of the previous expression, it is ignored + b.add(parserLine,POP); + startExpr(b,-1); + break; + } default: { pushBackToken(); return; @@ -435,6 +446,21 @@ class Parser extends Lexer implements ByteCodes { continueExpr(b, minPrecedence); // try to continue the expression } + // parse a set of comma separated function arguments, assume LP has already been consumed + private int parseArgs(CompiledFunctionImpl b) throws IOException { + int i = 0; + while(peekToken() != RP) { + i++; + if (peekToken() != COMMA) { + startExpr(b, NO_COMMA); + if (peekToken() == RP) break; + } + consume(COMMA); + } + consume(RP); + return i; + } + /** Parse a block of statements which must be surrounded by LC..RC. */ void parseBlock(CompiledFunctionImpl b) throws IOException { parseBlock(b, null); } void parseBlock(CompiledFunctionImpl b, String label) throws IOException { @@ -482,16 +508,15 @@ class Parser extends Lexer implements ByteCodes { b.add(parserLine, TOPSCOPE); // push the current scope while(true) { consume(NAME); - String name = string; - b.add(parserLine, LITERAL, name); // push the name to be declared - b.add(parserLine, DECLARE); // declare it + b.add(parserLine, DECLARE, string); // declare it if (peekToken() == ASSIGN) { // if there is an '=' after the variable name - b.add(parserLine, LITERAL, name); // put the var name back on the stack consume(ASSIGN); - startExpr(b, -1); + startExpr(b, NO_COMMA); b.add(parserLine, PUT); // 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); } @@ -561,7 +586,7 @@ class Parser extends Lexer implements ByteCodes { b.add(parserLine, BREAK); // break out of the loop if we 'fall through' break; } else { - throw new ParserException("expected CASE, DEFAULT, or RC; got " + codeToString[peekToken()]); + throw pe("expected CASE, DEFAULT, or RC; got " + codeToString[peekToken()]); } b.set(size0 - 1, new Integer(b.size() - size0 + 1)); // end of the loop break; @@ -585,37 +610,56 @@ class Parser extends Lexer implements ByteCodes { } case TRY: { - b.add(parserLine, TRY); - int size = b.size(); - parseStatement(b, null); // parse the expression to be TRYed - b.add(parserLine, POP); // pop the TryMarker - b.add(parserLine, 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 + b.add(parserLine, TRY); // try bytecode causes a TryMarker to be pushed + int tryInsn = b.size() - 1; + // parse the expression to be TRYed + parseStatement(b, null); + // pop the try marker. this is pushed when the TRY bytecode is executed + b.add(parserLine, POP); + // jump forward to the end of the catch block, start of the finally block + b.add(parserLine, JMP); + int successJMPInsn = b.size() - 1; + + if (peekToken() != CATCH && peekToken() != FINALLY) + throw pe("try without catch or finally"); + int catchJMPDistance = -1; if (peekToken() == CATCH) { + catchJMPDistance = b.size() - tryInsn; + String exceptionVar; getToken(); consume(LP); consume(NAME); + exceptionVar = string; consume(RP); b.add(parserLine, TOPSCOPE); // the exception is on top of the stack; put it to the chosen name b.add(parserLine, SWAP); - b.add(parserLine, LITERAL); + b.add(parserLine, LITERAL,exceptionVar); b.add(parserLine, SWAP); b.add(parserLine, PUT); b.add(parserLine, POP); b.add(parserLine, POP); parseStatement(b, null); + // pop the try and catch markers + b.add(parserLine,POP); + b.add(parserLine,POP); } // jump here if no exception was thrown - b.set(size2 - 1, new Integer(b.size() - size2 + 1)); - - // FIXME: not implemented correctly + b.set(successJMPInsn, new Integer(b.size() - successJMPInsn)); + + int finallyJMPDistance = -1; if (peekToken() == FINALLY) { + b.add(parserLine, LITERAL, null); // null FinallyData + finallyJMPDistance = b.size() - tryInsn; consume(FINALLY); parseStatement(b, null); + b.add(parserLine,FINALLY_DONE); } + + // setup the TRY arguments + b.set(tryInsn, new int[] { catchJMPDistance, finallyJMPDistance }); + break; } @@ -735,8 +779,7 @@ class Parser extends Lexer implements ByteCodes { // ParserException ////////////////////////////////////////////////////////////////////// - - private class ParserException extends IOException { public ParserException(String s) { super(sourceName + ":" + parserLine + " " + s); } } + private IOException pe(String s) { return new IOException(sourceName + ":" + parserLine + " " + s); } }