codegenerator.java

antlr最新版本V3源代码

			}
		}
	}

	/** Generate a token names table that maps token type to a printable
	 *  name: either the label like INT or the literal like "begin".
	 */
	protected void genTokenTypeNames(StringTemplate code) {
		for (int t=Label.MIN_TOKEN_TYPE; t<=grammar.getMaxTokenType(); t++) {
			String tokenName = grammar.getTokenDisplayName(t);
			if ( tokenName!=null ) {
				tokenName=target.getTargetStringLiteralFromString(tokenName, true);
				code.setAttribute("tokenNames", tokenName);
			}
		}
	}

	/** Get a meaningful name for a token type useful during code generation.
	 *  Literals without associated names are converted to the string equivalent
	 *  of their integer values. Used to generate x==ID and x==34 type comparisons
	 *  etc...  Essentially we are looking for the most obvious way to refer
	 *  to a token type in the generated code.  If in the lexer, return the
	 *  char literal translated to the target language.  For example, ttype=10
	 *  will yield '\n' from the getTokenDisplayName method.  That must
	 *  be converted to the target languages literals.  For most C-derived
	 *  languages no translation is needed.
	 */
	public String getTokenTypeAsTargetLabel(int ttype) {
		if ( grammar.type==Grammar.LEXER ) {
			String name = grammar.getTokenDisplayName(ttype);
			return target.getTargetCharLiteralFromANTLRCharLiteral(this,name);
		}
		return target.getTokenTypeAsTargetLabel(this,ttype);
	}

	/** Generate a token vocab file with all the token names/types.  For example:
	 *  ID=7
	 *  FOR=8
	 *  'for'=8
	 *
	 *  This is independent of the target language; used by antlr internally
	 */
	protected StringTemplate genTokenVocabOutput() {
		StringTemplate vocabFileST =
			new StringTemplate(vocabFilePattern,
							   AngleBracketTemplateLexer.class);
		vocabFileST.setName("vocab-file");
		// make constants for the token names
		Iterator tokenIDs = grammar.getTokenIDs().iterator();
		while (tokenIDs.hasNext()) {
			String tokenID = (String) tokenIDs.next();
			int tokenType = grammar.getTokenType(tokenID);
			if ( tokenType>=Label.MIN_TOKEN_TYPE ) {
				vocabFileST.setAttribute("tokens.{name,type}", tokenID, Utils.integer(tokenType));
			}
		}

		// now dump the strings
		Iterator literals = grammar.getStringLiterals().iterator();
		while (literals.hasNext()) {
			String literal = (String) literals.next();
			int tokenType = grammar.getTokenType(literal);
			if ( tokenType>=Label.MIN_TOKEN_TYPE ) {
				vocabFileST.setAttribute("tokens.{name,type}", literal, Utils.integer(tokenType));
			}
		}

		return vocabFileST;
	}

	public List translateAction(String ruleName,
								GrammarAST actionTree)
	{
		if ( actionTree.getType()==ANTLRParser.ARG_ACTION ) {
			return translateArgAction(ruleName, actionTree);
		}
		ActionTranslatorLexer translator = new ActionTranslatorLexer(this,ruleName,actionTree);
		List chunks = translator.translateToChunks();
		chunks = target.postProcessAction(chunks, actionTree.token);
		return chunks;
	}

	/** Translate an action like [3,"foo",a[3]] and return a List of the
	 *  translated actions.  Because actions are translated to a list of
	 *  chunks, this returns List<List<String|StringTemplate>>.
	 *
	 *  Simple ',' separator is assumed.
	 */
	public List translateArgAction(String ruleName,
								   GrammarAST actionTree)
	{
		String actionText = actionTree.token.getText();
		StringTokenizer argTokens = new StringTokenizer(actionText, ",");
		List args = new ArrayList();
		while ( argTokens.hasMoreTokens() ) {
			String arg = (String)argTokens.nextToken();
			antlr.Token actionToken = new antlr.CommonToken(ANTLRParser.ACTION,arg);
			ActionTranslatorLexer translator =
				new ActionTranslatorLexer(this,ruleName,
										  actionToken,
										  actionTree.outerAltNum);
			List chunks = translator.translateToChunks();
			chunks = target.postProcessAction(chunks, actionToken);
			args.add(chunks);
		}
		if ( args.size()==0 ) {
			return null;
		}
		return args;
	}

	/** Given a template constructor action like %foo(a={...}) in
	 *  an action, translate it to the appropriate template constructor
	 *  from the templateLib. This translates a *piece* of the action.
	 */
	public StringTemplate translateTemplateConstructor(String ruleName,
													   int outerAltNum,
													   antlr.Token actionToken,
													   String templateActionText)
	{
		// first, parse with antlr.g
		//System.out.println("translate template: "+templateActionText);
		ANTLRLexer lexer = new ANTLRLexer(new StringReader(templateActionText));
		lexer.setFilename(grammar.getFileName());
		lexer.setTokenObjectClass("antlr.TokenWithIndex");
		TokenStreamRewriteEngine tokenBuffer = new TokenStreamRewriteEngine(lexer);
		tokenBuffer.discard(ANTLRParser.WS);
		tokenBuffer.discard(ANTLRParser.ML_COMMENT);
		tokenBuffer.discard(ANTLRParser.COMMENT);
		tokenBuffer.discard(ANTLRParser.SL_COMMENT);
		ANTLRParser parser = new ANTLRParser(tokenBuffer);
		parser.setFilename(grammar.getFileName());
		parser.setASTNodeClass("org.antlr.tool.GrammarAST");
		try {
			parser.rewrite_template();
		}
		catch (RecognitionException re) {
			ErrorManager.grammarError(ErrorManager.MSG_INVALID_TEMPLATE_ACTION,
										  grammar,
										  actionToken,
										  templateActionText);
		}
		catch (Exception tse) {
			ErrorManager.internalError("can't parse template action",tse);
		}
		GrammarAST rewriteTree = (GrammarAST)parser.getAST();

		// then translate via codegen.g
		CodeGenTreeWalker gen = new CodeGenTreeWalker();
		gen.init(grammar);
		gen.currentRuleName = ruleName;
		gen.outerAltNum = outerAltNum;
		StringTemplate st = null;
		try {
			st = gen.rewrite_template((AST)rewriteTree);
		}
		catch (RecognitionException re) {
			ErrorManager.error(ErrorManager.MSG_BAD_AST_STRUCTURE,
							   re);
		}
		return st;
	}


	public void issueInvalidScopeError(String x,
									   String y,
									   Rule enclosingRule,
									   antlr.Token actionToken,
									   int outerAltNum)
	{
		//System.out.println("error $"+x+"::"+y);
		Rule r = grammar.getRule(x);
		AttributeScope scope = grammar.getGlobalScope(x);
		if ( scope==null ) {
			if ( r!=null ) {
				scope = r.ruleScope; // if not global, might be rule scope
			}
		}
		if ( scope==null ) {
			ErrorManager.grammarError(ErrorManager.MSG_UNKNOWN_DYNAMIC_SCOPE,
										  grammar,
										  actionToken,
										  x);
		}
		else if ( scope.getAttribute(y)==null ) {
			ErrorManager.grammarError(ErrorManager.MSG_UNKNOWN_DYNAMIC_SCOPE_ATTRIBUTE,
										  grammar,
										  actionToken,
										  x,
										  y);
		}
	}

	public void issueInvalidAttributeError(String x,
										   String y,
										   Rule enclosingRule,
										   antlr.Token actionToken,
										   int outerAltNum)
	{
		//System.out.println("error $"+x+"."+y);
		if ( enclosingRule==null ) {
			// action not in a rule
			ErrorManager.grammarError(ErrorManager.MSG_ATTRIBUTE_REF_NOT_IN_RULE,
										  grammar,
										  actionToken,
										  x,
										  y);
			return;
		}

		// action is in a rule
		Grammar.LabelElementPair label = enclosingRule.getRuleLabel(x);

		if ( label!=null || enclosingRule.getRuleRefsInAlt(x, outerAltNum)!=null ) {
			// $rulelabel.attr or $ruleref.attr; must be unknown attr
			String refdRuleName = x;
			if ( label!=null ) {
				refdRuleName = enclosingRule.getRuleLabel(x).referencedRuleName;
			}
			Rule refdRule = grammar.getRule(refdRuleName);
			AttributeScope scope = refdRule.getAttributeScope(y);
			if ( scope==null ) {
				ErrorManager.grammarError(ErrorManager.MSG_UNKNOWN_RULE_ATTRIBUTE,
										  grammar,
										  actionToken,
										  refdRuleName,
										  y);
			}
			else if ( scope.isParameterScope ) {
				ErrorManager.grammarError(ErrorManager.MSG_INVALID_RULE_PARAMETER_REF,
										  grammar,
										  actionToken,
										  refdRuleName,
										  y);
			}
			else if ( scope.isDynamicRuleScope ) {
				ErrorManager.grammarError(ErrorManager.MSG_INVALID_RULE_SCOPE_ATTRIBUTE_REF,
										  grammar,
										  actionToken,
										  refdRuleName,
										  y);
			}
		}

	}

	public void issueInvalidAttributeError(String x,
										   Rule enclosingRule,
										   antlr.Token actionToken,
										   int outerAltNum)
	{
		//System.out.println("error $"+x);
		if ( enclosingRule==null ) {
			// action not in a rule
			ErrorManager.grammarError(ErrorManager.MSG_ATTRIBUTE_REF_NOT_IN_RULE,
										  grammar,
										  actionToken,
										  x);
			return;
		}

		// action is in a rule
		Grammar.LabelElementPair label = enclosingRule.getRuleLabel(x);
		AttributeScope scope = enclosingRule.getAttributeScope(x);

		if ( label!=null ||
			 enclosingRule.getRuleRefsInAlt(x, outerAltNum)!=null ||
			 enclosingRule.name.equals(x) )
		{
			ErrorManager.grammarError(ErrorManager.MSG_ISOLATED_RULE_SCOPE,
										  grammar,
										  actionToken,
										  x);
		}
		else if ( scope!=null && scope.isDynamicRuleScope ) {
			ErrorManager.grammarError(ErrorManager.MSG_ISOLATED_RULE_ATTRIBUTE,
										  grammar,
										  actionToken,
										  x);
		}
		else {
			ErrorManager.grammarError(ErrorManager.MSG_UNKNOWN_SIMPLE_ATTRIBUTE,
									  grammar,
									  actionToken,
									  x);
		}
	}

	// M I S C

	public StringTemplateGroup getTemplates() {
		return templates;
	}

	public StringTemplateGroup getBaseTemplates() {
		return baseTemplates;
	}

	public void setDebug(boolean debug) {
		this.debug = debug;
	}

	public void setTrace(boolean trace) {
		this.trace = trace;
	}

	public void setProfile(boolean profile) {
		this.profile = profile;
		if ( profile ) {
			setDebug(true); // requires debug events
		}
	}

	public StringTemplate getRecognizerST() {
		return outputFileST;
	}

	public String getRecognizerFileName(String name, int type) {
		StringTemplate extST = templates.getInstanceOf("codeFileExtension");
		String suffix = Grammar.grammarTypeToFileNameSuffix[type];
		return name+suffix+extST.toString();
	}

	/** What is the name of the vocab file generated for this grammar?
	 *  Returns null if no .tokens file should be generated.
	 */
	public String getVocabFileName() {
		if ( grammar.isBuiltFromString() ) {
			return null;
		}
		return grammar.name+VOCAB_FILE_EXTENSION;
	}

	public void write(StringTemplate code, String fileName) throws IOException {
		long start = System.currentTimeMillis();
		Writer w = tool.getOutputFile(grammar, fileName);
		// Write the output to a StringWriter
		StringTemplateWriter wr = templates.getStringTemplateWriter(w);
		wr.setLineWidth(lineWidth);
		code.write(wr);
		w.close();
		long stop = System.currentTimeMillis();
		//System.out.println("render time for "+fileName+": "+(int)(stop-start)+"ms");
	}

	/** You can generate a switch rather than if-then-else for a DFA state
	 *  if there are no semantic predicates and the number of edge label
	 *  values is small enough; e.g., don't generate a switch for a state
	 *  containing an edge label such as 20..52330 (the resulting byte codes
	 *  would overflow the method 65k limit probably).
	 */
	protected boolean canGenerateSwitch(DFAState s) {
		if ( !GENERATE_SWITCHES_WHEN_POSSIBLE ) {
			return false;
		}
		int size = 0;
		for (int i = 0; i < s.getNumberOfTransitions(); i++) {
			Transition edge = (Transition) s.transition(i);
			if ( edge.label.isSemanticPredicate() ) {
				return false;
			}
			// can't do a switch if the edges are going to require predicates
			if ( edge.label.getAtom()==Label.EOT ) {
				int EOTPredicts = ((DFAState)edge.target).getUniquelyPredictedAlt();
				if ( EOTPredicts==NFA.INVALID_ALT_NUMBER ) {
					// EOT target has to be a predicate then; no unique alt
					return false;
				}
			}
			// if target is a state with gated preds, we need to use preds on
			// this edge then to reach it.
			if ( ((DFAState)edge.target).getGatedPredicatesInNFAConfigurations()!=null ) {
				return false;
			}
			size += edge.label.getSet().size();
		}
		if ( s.getNumberOfTransitions()<MIN_SWITCH_ALTS ||
			 size>MAX_SWITCH_CASE_LABELS ) {
			return false;
		}
		return true;
	}

	/** Create a label to track a token / rule reference's result.
	 *  Technically, this is a place where I break model-view separation
	 *  as I am creating a variable name that could be invalid in a
	 *  target language, however, label ::= <ID><INT> is probably ok in
	 *  all languages we care about.
	 */
	public String createUniqueLabel(String name) {
		return new StringBuffer()
			.append(name).append(uniqueLabelNumber++).toString();
	}
}