org.antlr.v4.misc.OrderedHashMap Java Examples

/** Return true if successful */
	public boolean translateLeftRecursiveRule(GrammarRootAST ast,
											  LeftRecursiveRule r,
											  String language)
	{
		//tool.log("grammar", ruleAST.toStringTree());
		GrammarAST prevRuleAST = r.ast;
		String ruleName = prevRuleAST.getChild(0).getText();
		LeftRecursiveRuleAnalyzer leftRecursiveRuleWalker =
			new LeftRecursiveRuleAnalyzer(prevRuleAST, tool, ruleName, language);
		boolean isLeftRec;
		try {
//			System.out.println("TESTING ---------------\n"+
//							   leftRecursiveRuleWalker.text(ruleAST));
			isLeftRec = leftRecursiveRuleWalker.rec_rule();
		}
		catch (RecognitionException re) {
			isLeftRec = false; // didn't match; oh well
		}
		if ( !isLeftRec ) return false;

		// replace old rule's AST; first create text of altered rule
		GrammarAST RULES = (GrammarAST)ast.getFirstChildWithType(ANTLRParser.RULES);
		String newRuleText = leftRecursiveRuleWalker.getArtificialOpPrecRule();
//		System.out.println("created: "+newRuleText);
		// now parse within the context of the grammar that originally created
		// the AST we are transforming. This could be an imported grammar so
		// we cannot just reference this.g because the role might come from
		// the imported grammar and not the root grammar (this.g)
		RuleAST t = parseArtificialRule(prevRuleAST.g, newRuleText);

		// reuse the name token from the original AST since it refers to the proper source location in the original grammar
		((GrammarAST)t.getChild(0)).token = ((GrammarAST)prevRuleAST.getChild(0)).getToken();

		// update grammar AST and set rule's AST.
		RULES.setChild(prevRuleAST.getChildIndex(), t);
		r.ast = t;

		// Reduce sets in newly created rule tree
		GrammarTransformPipeline transform = new GrammarTransformPipeline(g, g.tool);
		transform.reduceBlocksToSets(r.ast);
		transform.expandParameterizedLoops(r.ast);

		// Rerun semantic checks on the new rule
		RuleCollector ruleCollector = new RuleCollector(g);
		ruleCollector.visit(t, "rule");
		BasicSemanticChecks basics = new BasicSemanticChecks(g, ruleCollector);
		// disable the assoc element option checks because they are already
		// handled for the pre-transformed rule.
		basics.checkAssocElementOption = false;
		basics.visit(t, "rule");

		// track recursive alt info for codegen
		r.recPrimaryAlts = new ArrayList<LeftRecursiveRuleAltInfo>();
		r.recPrimaryAlts.addAll(leftRecursiveRuleWalker.prefixAndOtherAlts);
		if (r.recPrimaryAlts.isEmpty()) {
			tool.errMgr.grammarError(ErrorType.NO_NON_LR_ALTS, g.fileName, ((GrammarAST)r.ast.getChild(0)).getToken(), r.name);
		}

		r.recOpAlts = new OrderedHashMap<Integer, LeftRecursiveRuleAltInfo>();
		r.recOpAlts.putAll(leftRecursiveRuleWalker.binaryAlts);
		r.recOpAlts.putAll(leftRecursiveRuleWalker.ternaryAlts);
		r.recOpAlts.putAll(leftRecursiveRuleWalker.suffixAlts);

		// walk alt info records and set their altAST to point to appropriate ALT subtree
		// from freshly created AST
		setAltASTPointers(r, t);

		// update Rule to just one alt and add prec alt
		ActionAST arg = (ActionAST)r.ast.getFirstChildWithType(ANTLRParser.ARG_ACTION);
		if ( arg!=null ) {
			r.args = ScopeParser.parseTypedArgList(arg, arg.getText(), g);
			r.args.type = AttributeDict.DictType.ARG;
			r.args.ast = arg;
			arg.resolver = r.alt[1]; // todo: isn't this Rule or something?
		}

		// define labels on recursive rule refs we delete; they don't point to nodes of course
		// these are so $label in action translation works
		for (Pair<GrammarAST,String> pair : leftRecursiveRuleWalker.leftRecursiveRuleRefLabels) {
			GrammarAST labelNode = pair.a;
			GrammarAST labelOpNode = (GrammarAST)labelNode.getParent();
			GrammarAST elementNode = (GrammarAST)labelOpNode.getChild(1);
			LabelElementPair lp = new LabelElementPair(g, labelNode, elementNode, labelOpNode.getType());
			r.alt[1].labelDefs.map(labelNode.getText(), lp);
		}
		// copy to rule from walker
		r.leftRecursiveRuleRefLabels = leftRecursiveRuleWalker.leftRecursiveRuleRefLabels;

		tool.log("grammar", "added: "+t.toStringTree());
		return true;
	}