Examples with BasicSemanticChecks org.antlr.v4.semantics.BasicSemanticChecks used on opensource projects

Example 1 with BasicSemanticChecks

use of org.antlr.v4.semantics.BasicSemanticChecks in project antlr4 by antlr.

the class LeftRecursiveRuleTransformer method translateLeftRecursiveRule.

/** 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) {
        // didn't match; oh well
        isLeftRec = false;
    }
    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;
        // todo: isn't this Rule or something?
        arg.resolver = r.alt[1];
    }
    // 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;
}

Example 2 with BasicSemanticChecks

use of org.antlr.v4.semantics.BasicSemanticChecks in project antlr4 by antlr.

the class SemanticPipeline method process.

public void process() {
    if (g.ast == null)
        return;
    // COLLECT RULE OBJECTS
    RuleCollector ruleCollector = new RuleCollector(g);
    ruleCollector.process(g.ast);
    // DO BASIC / EASY SEMANTIC CHECKS
    int prevErrors = g.tool.errMgr.getNumErrors();
    BasicSemanticChecks basics = new BasicSemanticChecks(g, ruleCollector);
    basics.process();
    if (g.tool.errMgr.getNumErrors() > prevErrors)
        return;
    // TRANSFORM LEFT-RECURSIVE RULES
    prevErrors = g.tool.errMgr.getNumErrors();
    LeftRecursiveRuleTransformer lrtrans = new LeftRecursiveRuleTransformer(g.ast, ruleCollector.rules.values(), g);
    lrtrans.translateLeftRecursiveRules();
    // don't continue if we got errors during left-recursion elimination
    if (g.tool.errMgr.getNumErrors() > prevErrors)
        return;
    // STORE RULES IN GRAMMAR
    for (Rule r : ruleCollector.rules.values()) {
        g.defineRule(r);
    }
    // COLLECT SYMBOLS: RULES, ACTIONS, TERMINALS, ...
    SymbolCollector collector = new SymbolCollector(g);
    collector.process(g.ast);
    // CHECK FOR SYMBOL COLLISIONS
    SymbolChecks symcheck = new SymbolChecks(g, collector);
    // side-effect: strip away redef'd rules.
    symcheck.process();
    for (GrammarAST a : collector.namedActions) {
        g.defineAction(a);
    }
    // LINK (outermost) ALT NODES WITH Alternatives
    for (Rule r : g.rules.values()) {
        for (int i = 1; i <= r.numberOfAlts; i++) {
            r.alt[i].ast.alt = r.alt[i];
        }
    }
    // ASSIGN TOKEN TYPES
    g.importTokensFromTokensFile();
    if (g.isLexer()) {
        assignLexerTokenTypes(g, collector.tokensDefs);
    } else {
        assignTokenTypes(g, collector.tokensDefs, collector.tokenIDRefs, collector.terminals);
    }
    symcheck.checkForModeConflicts(g);
    assignChannelTypes(g, collector.channelDefs);
    // CHECK RULE REFS NOW (that we've defined rules in grammar)
    symcheck.checkRuleArgs(g, collector.rulerefs);
    identifyStartRules(collector);
    symcheck.checkForQualifiedRuleIssues(g, collector.qualifiedRulerefs);
    // don't continue if we got symbol errors
    if (g.tool.getNumErrors() > 0)
        return;
    // CHECK ATTRIBUTE EXPRESSIONS FOR SEMANTIC VALIDITY
    AttributeChecks.checkAllAttributeExpressions(g);
    UseDefAnalyzer.trackTokenRuleRefsInActions(g);
}