codegentreewalker.java

ANTLR(ANother Tool for Language Recognition)它是这样的一种工具

		GrammarAST a = null;
		
		// TODO: can we use Rule.altsWithRewrites???
		if ( blockNestingLevel==RULE_BLOCK_NESTING_LEVEL ) {
			GrammarAST aRewriteNode = alternative_AST_in.findFirstType(REWRITE);
			if ( grammar.buildAST() &&
				 (aRewriteNode!=null||
				 (alternative_AST_in.getNextSibling()!=null &&
				  alternative_AST_in.getNextSibling().getType()==REWRITE)) )
			{
				currentAltHasASTRewrite = true;
			}
			else {
				currentAltHasASTRewrite = false;
			}
		}
		String description = grammar.grammarTreeToString(alternative_AST_in, false);
		description = generator.target.getTargetStringLiteralFromString(description);
		code.setAttribute("description", description);
		if ( !currentAltHasASTRewrite && grammar.buildAST() ) {
			code.setAttribute("autoAST", Boolean.valueOf(true));
		}
		StringTemplate e;
		
		
		try {      // for error handling
			AST __t58 = _t;
			a = _t==ASTNULL ? null :(GrammarAST)_t;
			match(_t,ALT);
			_t = _t.getFirstChild();
			{
			int _cnt60=0;
			_loop60:
			do {
				if (_t==null) _t=ASTNULL;
				if ((_t.getType()==BLOCK||_t.getType()==OPTIONAL||_t.getType()==CLOSURE||_t.getType()==POSITIVE_CLOSURE||_t.getType()==CHAR_RANGE||_t.getType()==EPSILON||_t.getType()==SET||_t.getType()==GATED_SEMPRED||_t.getType()==SYN_SEMPRED||_t.getType()==ACTION||_t.getType()==ASSIGN||_t.getType()==STRING_LITERAL||_t.getType()==CHAR_LITERAL||_t.getType()==TOKEN_REF||_t.getType()==PLUS_ASSIGN||_t.getType()==SEMPRED||_t.getType()==NOT||_t.getType()==TREE_BEGIN||_t.getType()==RULE_REF||_t.getType()==WILDCARD)) {
					GrammarAST elAST=(GrammarAST)_t;
					e=element(_t);
					_t = _retTree;
					
								if ( e!=null ) {
										code.setAttribute("elements.{el,line,pos}",
														  e,
														  Utils.integer(elAST.getLine()),
														  Utils.integer(elAST.getColumn())
														 );
								}
								
				}
				else {
					if ( _cnt60>=1 ) { break _loop60; } else {throw new NoViableAltException(_t);}
				}
				
				_cnt60++;
			} while (true);
			}
			GrammarAST tmp33_AST_in = (GrammarAST)_t;
			match(_t,EOA);
			_t = _t.getNextSibling();
			_t = __t58;
			_t = _t.getNextSibling();
		}
		catch (RecognitionException ex) {
			reportError(ex);
			if (_t!=null) {_t = _t.getNextSibling();}
		}
		_retTree = _t;
		return code;
	}
	
	public final StringTemplate  rewrite(AST _t) throws RecognitionException {
		StringTemplate code=null;
		
		GrammarAST rewrite_AST_in = (_t == ASTNULL) ? null : (GrammarAST)_t;
		GrammarAST r = null;
		GrammarAST pred = null;
		
		StringTemplate alt;
		if ( rewrite_AST_in.getType()==REWRITE ) {
			if ( generator.grammar.buildTemplate() ) {
				code = templates.getInstanceOf("rewriteTemplate");
			}
			else {
				code = templates.getInstanceOf("rewriteCode");
				code.setAttribute("treeLevel", Utils.integer(OUTER_REWRITE_NESTING_LEVEL));
				code.setAttribute("rewriteBlockLevel", Utils.integer(OUTER_REWRITE_NESTING_LEVEL));
				currentBlockST = code;
			}
		}
		
		
		try {      // for error handling
			{
			_loop121:
			do {
				if (_t==null) _t=ASTNULL;
				if ((_t.getType()==REWRITE)) {
					rewriteRuleRefs = new HashSet();
					AST __t119 = _t;
					r = _t==ASTNULL ? null :(GrammarAST)_t;
					match(_t,REWRITE);
					_t = _t.getFirstChild();
					{
					if (_t==null) _t=ASTNULL;
					switch ( _t.getType()) {
					case SEMPRED:
					{
						pred = (GrammarAST)_t;
						match(_t,SEMPRED);
						_t = _t.getNextSibling();
						break;
					}
					case ALT:
					case TEMPLATE:
					case ACTION:
					{
						break;
					}
					default:
					{
						throw new NoViableAltException(_t);
					}
					}
					}
					alt=rewrite_alternative(_t);
					_t = _retTree;
					_t = __t119;
					_t = _t.getNextSibling();
					
					rewriteBlockNestingLevel = OUTER_REWRITE_NESTING_LEVEL;
								List predChunks = null;
								if ( pred!=null ) {
									//predText = #pred.getText();
							pred.outerAltNum = this.outerAltNum;
							predChunks = generator.translateAction(currentRuleName,pred);
								}
								String description =
								    grammar.grammarTreeToString(r,false);
								description = generator.target.getTargetStringLiteralFromString(description);
								code.setAttribute("alts.{pred,alt,description}",
												  predChunks,
												  alt,
												  description);
								pred=null;
								
				}
				else {
					break _loop121;
				}
				
			} while (true);
			}
		}
		catch (RecognitionException ex) {
			reportError(ex);
			if (_t!=null) {_t = _t.getNextSibling();}
		}
		_retTree = _t;
		return code;
	}
	
	public final void exceptionSpec(AST _t,
		StringTemplate ruleST
	) throws RecognitionException {
		
		GrammarAST exceptionSpec_AST_in = (_t == ASTNULL) ? null : (GrammarAST)_t;
		
		try {      // for error handling
			AST __t51 = _t;
			GrammarAST tmp34_AST_in = (GrammarAST)_t;
			match(_t,LITERAL_exception);
			_t = _t.getFirstChild();
			{
			if (_t==null) _t=ASTNULL;
			switch ( _t.getType()) {
			case ARG_ACTION:
			{
				GrammarAST tmp35_AST_in = (GrammarAST)_t;
				match(_t,ARG_ACTION);
				_t = _t.getNextSibling();
				break;
			}
			case 3:
			case LITERAL_catch:
			{
				break;
			}
			default:
			{
				throw new NoViableAltException(_t);
			}
			}
			}
			{
			_loop54:
			do {
				if (_t==null) _t=ASTNULL;
				if ((_t.getType()==LITERAL_catch)) {
					exceptionHandler(_t,ruleST);
					_t = _retTree;
				}
				else {
					break _loop54;
				}
				
			} while (true);
			}
			_t = __t51;
			_t = _t.getNextSibling();
		}
		catch (RecognitionException ex) {
			reportError(ex);
			if (_t!=null) {_t = _t.getNextSibling();}
		}
		_retTree = _t;
	}
	
	public final void exceptionHandler(AST _t,
		StringTemplate ruleST
	) throws RecognitionException {
		
		GrammarAST exceptionHandler_AST_in = (_t == ASTNULL) ? null : (GrammarAST)_t;
		
		try {      // for error handling
			AST __t56 = _t;
			GrammarAST tmp36_AST_in = (GrammarAST)_t;
			match(_t,LITERAL_catch);
			_t = _t.getFirstChild();
			GrammarAST tmp37_AST_in = (GrammarAST)_t;
			match(_t,ARG_ACTION);
			_t = _t.getNextSibling();
			GrammarAST tmp38_AST_in = (GrammarAST)_t;
			match(_t,ACTION);
			_t = _t.getNextSibling();
			_t = __t56;
			_t = _t.getNextSibling();
			
				List chunks = generator.translateAction(currentRuleName,tmp38_AST_in);
				ruleST.setAttribute("exceptions.{decl,action}",tmp37_AST_in.getText(),chunks);
				
		}
		catch (RecognitionException ex) {
			reportError(ex);
			if (_t!=null) {_t = _t.getNextSibling();}
		}
		_retTree = _t;
	}
	
	public final StringTemplate  element(AST _t) throws RecognitionException {
		StringTemplate code=null;
		
		GrammarAST element_AST_in = (_t == ASTNULL) ? null : (GrammarAST)_t;
		GrammarAST n = null;
		GrammarAST c = null;
		GrammarAST ast1 = null;
		GrammarAST s = null;
		GrammarAST ast2 = null;
		GrammarAST t = null;
		GrammarAST ast3 = null;
		GrammarAST st = null;
		GrammarAST ast4 = null;
		GrammarAST a = null;
		GrammarAST b = null;
		GrammarAST label = null;
		GrammarAST assign_n = null;
		GrammarAST assign_c = null;
		GrammarAST assign_ast1 = null;
		GrammarAST assign_s = null;
		GrammarAST assign_ast2 = null;
		GrammarAST assign_t = null;
		GrammarAST assign_ast3 = null;
		GrammarAST assign_st = null;
		GrammarAST assign_ast4 = null;
		GrammarAST label2 = null;
		GrammarAST act = null;
		GrammarAST sp = null;
		GrammarAST gsp = null;
		
		IntSet elements=null;
		GrammarAST ast = null;
		
		
		try {      // for error handling
			if (_t==null) _t=ASTNULL;
			switch ( _t.getType()) {
			case SET:
			case STRING_LITERAL:
			case CHAR_LITERAL:
			case TOKEN_REF:
			case RULE_REF:
			case WILDCARD:
			{
				code=atom(_t,null);
				_t = _retTree;
				break;
			}
			case NOT:
			{
				AST __t62 = _t;
				n = _t==ASTNULL ? null :(GrammarAST)_t;
				match(_t,NOT);
				_t = _t.getFirstChild();
				{
				if (_t==null) _t=ASTNULL;
				switch ( _t.getType()) {
				case CHAR_LITERAL:
				{
					AST __t64 = _t;
					c = _t==ASTNULL ? null :(GrammarAST)_t;
					match(_t,CHAR_LITERAL);
					_t = _t.getFirstChild();
					{
					if (_t==null) _t=ASTNULL;
					switch ( _t.getType()) {
					case BANG:
					case ROOT:
					case RULEROOT:
					{
						ast1 = _t==ASTNULL ? null : (GrammarAST)_t;
						ast_suffix(_t);
						_t = _retTree;
						break;
					}
					case 3:
					{
						break;
					}
					default:
					{
						throw new NoViableAltException(_t);
					}
					}
					}
					_t = __t64;
					_t = _t.getNextSibling();
					
						            int ttype=0;
								if ( grammar.type==Grammar.LEXER ) {
								ttype = Grammar.getCharValueFromGrammarCharLiteral(c.getText());
								}
								else {
								ttype = grammar.getTokenType(c.getText());
							}
						            elements = grammar.complement(ttype);
						            ast = ast1;
						
					break;
				}
				case STRING_LITERAL:
				{
					AST __t66 = _t;
					s = _t==ASTNULL ? null :(GrammarAST)_t;
					match(_t,STRING_LITERAL);
					_t = _t.getFirstChild();
					{
					if (_t==null) _t=ASTNULL;
					switch ( _t.getType()) {
					case BANG:
					case ROOT:
					case RULEROOT:
					{
						ast2 = _t==ASTNULL ? null : (GrammarAST)_t;
						ast_suffix(_t);
						_t = _retTree;
						break;
					}
					case 3:
					{
						break;
					}
					default:
					{
						throw new NoViableAltException(_t);
					}
					}
					}
					_t = __t66;
					_t = _t.getNextSibling();
					
						            int ttype=0;
								if ( grammar.type==Grammar.LEXER ) {
								// TODO: error!
								}
								else {
								ttype = grammar.getTokenType(s.getText());
							}
						            elements = grammar.complement(ttype);
						            ast = ast2;
						
					break;
				}
				case TOKEN_REF:
				{
					AST __t68 = _t;
					t = _t==ASTNULL ? null :(GrammarAST)_t;
					match(_t,TOKEN_REF);
					_t = _t.getFirstChild();
					{
					if (_t==null) _t=ASTNULL;
					switch ( _t.getType()) {
					case BANG:
					case ROOT:
					case RULEROOT:
					{
						ast3 = _t==ASTNULL ? null : (GrammarAST)_t;
						ast_suffix(_t);
						_t = _retTree;
						break;
					}
					case 3:
					{
						break;
					}
					default:
					{
						throw new NoViableAltException(_t);
					}
					}
					}
					_t = __t68;
					_t = _t.getNextSibling();
					
						           int ttype = grammar.getTokenType(t.getText());
						           elements = grammar.complement(ttype);
						           ast = ast3;
						
					break;
				}
				case SET:
				{
					AST __t70 = _t;
					st = _t==ASTNULL ? null :(GrammarAST)_t;
					match(_t,SET);
					_t = _t.getFirstChild();
					{
					int _cnt72=0;
					_loop72:
					do {
						if (_t==null) _t=ASTNULL;
						if ((_t.getType()==CHAR_RANGE||_t.getType()==STRING_LITERAL||_t.getType()==CHAR_LITERAL||_t.getType()==TOKEN_REF)) {
							setElement(_t);
							_t = _retTree;
						}
						else {
							if ( _cnt72>=1 ) { break _loop72; } else {throw new NoViableAltException(_t);}
						}
						
						_cnt72++;
					} while (true);
					}
					{
					if (_t==null) _t=ASTNULL;
					switch ( _t.getType()) {
					case BANG:
					case ROOT:
					case RULEROOT:
					{
						ast4 = _t==ASTNULL ? null : (GrammarAST)_t;
						ast_suffix(_t);
						_t = _retTree;
						break;
					}
					case 3:
					{
						break;
					}
					default:
					{
						throw new NoViableAltException(_t);
					}
					}
					}
					_t = __t70;
					_t = _t.getNextSibling();
					
					// SETs are not precomplemented by buildnfa.g like
					// simple elements.
					elements = st.getSetValue();
						           ast = ast4;
					
					break;
				}
				default:
				{
					throw new NoViableAltException(_t);
				}
				}
				}
				
				code = getTokenElementST("matchSet",
				"set",
				(GrammarAST)n.getFirstChild(),
				ast,
				null);
				code.setAttribute("s", generator.genSetExpr(templates,elements,1,false));
						 	code.setAttribute("elementIndex", ((TokenWithIndex)n.getToken()).getIndex());
							if ( grammar.type!=Grammar.LEXER ) {
						 		generator.generateLocalFOLLOW(n,"set",currentRuleName);
					}
				
				_t = __t62;
				_t = _t.getNextSibling();
				break;
			}
			case CHAR_RANGE:
			{
				AST __t74 = _t;
				GrammarAST tmp39_AST_in = (GrammarAST)_t;
				match(_t,CHAR_RANGE);
				_t = _t.getFirstChild();
				a = (GrammarAST)_t;
				match(_t,CHAR_LITERAL);
				_t = _t.getNextSibling();
				b = (GrammarAST)_t;
				match(_t,CHAR_LITERAL);
				_t = _t.getNextSibling();
				_t = __t74;
				_t = _t.getNextSibling();
				code = templates.getInstanceOf("charRangeRef");
						 String low =
						 	generator.target.getTargetCharLiteralFromANTLRCharLiteral(generator,a.getText());
						 String high =
						 	generator.target.getTargetCharLiteralFromANTLRCharLiteral(generator,b.getText());
				code.setAttribute("a", low);
				code.setAttribute("b", high);
				
				break;
			}
			case ASSIGN:
			{
				AST __t75 = _t;
				GrammarAST tmp40_AST_in = (GrammarAST)_t;
				match(_t,ASSIGN);
				_t = _t.getFirstChild();
				label = (GrammarAST)_t;
				match(_t,ID);
				_t = _t.getNextSibling();
				{
				if (_t==null) _t=ASTNULL;