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The ANTLR 4 grammar compiler.
/*
* Copyright (c) 2012 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD-3-Clause license that
* can be found in the LICENSE.txt file in the project root.
*/
package org.antlr.v4.semantics;
import org.antlr.runtime.ANTLRStringStream;
import org.antlr.runtime.Token;
import org.antlr.v4.parse.ActionSplitter;
import org.antlr.v4.parse.ActionSplitterListener;
import org.antlr.v4.tool.Alternative;
import org.antlr.v4.tool.ErrorManager;
import org.antlr.v4.tool.ErrorType;
import org.antlr.v4.tool.Grammar;
import org.antlr.v4.tool.LabelElementPair;
import org.antlr.v4.tool.LabelType;
import org.antlr.v4.tool.Rule;
import org.antlr.v4.tool.ast.ActionAST;
import org.antlr.v4.tool.ast.GrammarAST;
import java.util.List;
/** Trigger checks for various kinds of attribute expressions.
* no side-effects.
*/
public class AttributeChecks implements ActionSplitterListener {
public Grammar g;
public Rule r; // null if action outside of rule
public Alternative alt; // null if action outside of alt; could be in rule
public ActionAST node;
public Token actionToken; // token within action
public ErrorManager errMgr;
public AttributeChecks(Grammar g, Rule r, Alternative alt, ActionAST node, Token actionToken) {
this.g = g;
this.r = r;
this.alt = alt;
this.node = node;
this.actionToken = actionToken;
this.errMgr = g.tool.errMgr;
}
public static void checkAllAttributeExpressions(Grammar g) {
for (ActionAST act : g.namedActions.values()) {
AttributeChecks checker = new AttributeChecks(g, null, null, act, act.token);
checker.examineAction();
}
for (Rule r : g.rules.values()) {
for (ActionAST a : r.namedActions.values()) {
AttributeChecks checker = new AttributeChecks(g, r, null, a, a.token);
checker.examineAction();
}
for (int i=1; i<=r.numberOfAlts; i++) {
Alternative alt = r.alt[i];
for (ActionAST a : alt.actions) {
AttributeChecks checker =
new AttributeChecks(g, r, alt, a, a.token);
checker.examineAction();
}
}
for (GrammarAST e : r.exceptions) {
ActionAST a = (ActionAST)e.getChild(1);
AttributeChecks checker = new AttributeChecks(g, r, null, a, a.token);
checker.examineAction();
}
if ( r.finallyAction!=null ) {
AttributeChecks checker =
new AttributeChecks(g, r, null, r.finallyAction, r.finallyAction.token);
checker.examineAction();
}
}
}
public void examineAction() {
//System.out.println("examine "+actionToken);
ANTLRStringStream in = new ANTLRStringStream(actionToken.getText());
in.setLine(actionToken.getLine());
in.setCharPositionInLine(actionToken.getCharPositionInLine());
ActionSplitter splitter = new ActionSplitter(in, this);
// forces eval, triggers listener methods
node.chunks = splitter.getActionTokens();
}
// LISTENER METHODS
// $x.y
@Override
public void qualifiedAttr(String expr, Token x, Token y) {
if ( g.isLexer() ) {
errMgr.grammarError(ErrorType.ATTRIBUTE_IN_LEXER_ACTION,
g.fileName, x, x.getText()+"."+y.getText(), expr);
return;
}
if ( node.resolver.resolveToAttribute(x.getText(), node)!=null ) {
// must be a member access to a predefined attribute like $ctx.foo
attr(expr, x);
return;
}
if ( node.resolver.resolveToAttribute(x.getText(), y.getText(), node)==null ) {
Rule rref = isolatedRuleRef(x.getText());
if ( rref!=null ) {
if ( rref.args!=null && rref.args.get(y.getText())!=null ) {
g.tool.errMgr.grammarError(ErrorType.INVALID_RULE_PARAMETER_REF,
g.fileName, y, y.getText(), rref.name, expr);
}
else {
errMgr.grammarError(ErrorType.UNKNOWN_RULE_ATTRIBUTE,
g.fileName, y, y.getText(), rref.name, expr);
}
}
else if ( !node.resolver.resolvesToAttributeDict(x.getText(), node) ) {
errMgr.grammarError(ErrorType.UNKNOWN_SIMPLE_ATTRIBUTE,
g.fileName, x, x.getText(), expr);
}
else {
errMgr.grammarError(ErrorType.UNKNOWN_ATTRIBUTE_IN_SCOPE,
g.fileName, y, y.getText(), expr);
}
}
}
@Override
public void setAttr(String expr, Token x, Token rhs) {
if ( g.isLexer() ) {
errMgr.grammarError(ErrorType.ATTRIBUTE_IN_LEXER_ACTION,
g.fileName, x, x.getText(), expr);
return;
}
if ( node.resolver.resolveToAttribute(x.getText(), node)==null ) {
ErrorType errorType = ErrorType.UNKNOWN_SIMPLE_ATTRIBUTE;
if ( node.resolver.resolvesToListLabel(x.getText(), node) ) {
// $ids for ids+=ID etc...
errorType = ErrorType.ASSIGNMENT_TO_LIST_LABEL;
}
errMgr.grammarError(errorType,
g.fileName, x, x.getText(), expr);
}
new AttributeChecks(g, r, alt, node, rhs).examineAction();
}
@Override
public void attr(String expr, Token x) {
if ( g.isLexer() ) {
errMgr.grammarError(ErrorType.ATTRIBUTE_IN_LEXER_ACTION,
g.fileName, x, x.getText(), expr);
return;
}
if ( node.resolver.resolveToAttribute(x.getText(), node)==null ) {
if ( node.resolver.resolvesToToken(x.getText(), node) ) {
return; // $ID for token ref or label of token
}
if ( node.resolver.resolvesToListLabel(x.getText(), node) ) {
return; // $ids for ids+=ID etc...
}
if ( isolatedRuleRef(x.getText())!=null ) {
errMgr.grammarError(ErrorType.ISOLATED_RULE_REF,
g.fileName, x, x.getText(), expr);
return;
}
errMgr.grammarError(ErrorType.UNKNOWN_SIMPLE_ATTRIBUTE,
g.fileName, x, x.getText(), expr);
}
}
@Override
public void nonLocalAttr(String expr, Token x, Token y) {
Rule r = g.getRule(x.getText());
if ( r==null ) {
errMgr.grammarError(ErrorType.UNDEFINED_RULE_IN_NONLOCAL_REF,
g.fileName, x, x.getText(), y.getText(), expr);
}
else if ( r.resolveToAttribute(y.getText(), null)==null ) {
errMgr.grammarError(ErrorType.UNKNOWN_RULE_ATTRIBUTE,
g.fileName, y, y.getText(), x.getText(), expr);
}
}
@Override
public void setNonLocalAttr(String expr, Token x, Token y, Token rhs) {
Rule r = g.getRule(x.getText());
if ( r==null ) {
errMgr.grammarError(ErrorType.UNDEFINED_RULE_IN_NONLOCAL_REF,
g.fileName, x, x.getText(), y.getText(), expr);
}
else if ( r.resolveToAttribute(y.getText(), null)==null ) {
errMgr.grammarError(ErrorType.UNKNOWN_RULE_ATTRIBUTE,
g.fileName, y, y.getText(), x.getText(), expr);
}
}
@Override
public void text(String text) { }
// don't care
public void templateInstance(String expr) { }
public void indirectTemplateInstance(String expr) { }
public void setExprAttribute(String expr) { }
public void setSTAttribute(String expr) { }
public void templateExpr(String expr) { }
// SUPPORT
public Rule isolatedRuleRef(String x) {
if ( node.resolver instanceof Grammar ) return null;
if ( x.equals(r.name) ) return r;
List labels = null;
if ( node.resolver instanceof Rule ) {
labels = r.getElementLabelDefs().get(x);
}
else if ( node.resolver instanceof Alternative ) {
labels = ((Alternative)node.resolver).labelDefs.get(x);
}
if ( labels!=null ) { // it's a label ref. is it a rule label?
LabelElementPair anyLabelDef = labels.get(0);
if ( anyLabelDef.type==LabelType.RULE_LABEL ) {
return g.getRule(anyLabelDef.element.getText());
}
}
if ( node.resolver instanceof Alternative ) {
if ( ((Alternative)node.resolver).ruleRefs.get(x)!=null ) {
return g.getRule(x);
}
}
return null;
}
}