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The ANTLR 4 grammar compiler.
/*
* [The "BSD license"]
* Copyright (c) 2012 Terence Parr
* Copyright (c) 2012 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.v4.tool;
import org.antlr.v4.runtime.misc.MultiMap;
import org.antlr.v4.tool.ast.ActionAST;
import org.antlr.v4.tool.ast.AltAST;
import org.antlr.v4.tool.ast.GrammarAST;
import org.antlr.v4.tool.ast.TerminalAST;
import java.util.ArrayList;
import java.util.List;
/** An outermost alternative for a rule. We don't track inner alternatives. */
public class Alternative implements AttributeResolver {
public Rule rule;
public AltAST ast;
/** What alternative number is this outermost alt? 1..n */
public int altNum;
// token IDs, string literals in this alt
public MultiMap tokenRefs = new MultiMap();
// does not include labels
public MultiMap tokenRefsInActions = new MultiMap();
// all rule refs in this alt
public MultiMap ruleRefs = new MultiMap();
// does not include labels
public MultiMap ruleRefsInActions = new MultiMap();
/** A list of all LabelElementPair attached to tokens like id=ID, ids+=ID */
public MultiMap labelDefs = new MultiMap();
// track all token, rule, label refs in rewrite (right of ->)
//public List rewriteElements = new ArrayList();
/** Track all executable actions other than named actions like @init
* and catch/finally (not in an alt). Also tracks predicates, rewrite actions.
* We need to examine these actions before code generation so
* that we can detect refs to $rule.attr etc...
*
* This tracks per alt
*/
public List actions = new ArrayList();
public Alternative(Rule r, int altNum) { this.rule = r; this.altNum = altNum; }
@Override
public boolean resolvesToToken(String x, ActionAST node) {
if ( tokenRefs.get(x)!=null ) return true;
LabelElementPair anyLabelDef = getAnyLabelDef(x);
if ( anyLabelDef!=null && anyLabelDef.type==LabelType.TOKEN_LABEL ) return true;
return false;
}
@Override
public boolean resolvesToAttributeDict(String x, ActionAST node) {
if ( resolvesToToken(x, node) ) return true;
if ( ruleRefs.get(x)!=null ) return true; // rule ref in this alt?
LabelElementPair anyLabelDef = getAnyLabelDef(x);
if ( anyLabelDef!=null && anyLabelDef.type==LabelType.RULE_LABEL ) return true;
if ( x.equals(rule.name) ) return true; // $r for action in rule r, $r is a dict
return false;
}
/** $x Attribute: rule arguments, return values, predefined rule prop.
*/
@Override
public Attribute resolveToAttribute(String x, ActionAST node) {
return rule.resolveToAttribute(x, node); // reuse that code
}
/** $x.y, x can be surrounding rule, token/rule/label ref. y is visible
* attr in that dictionary. Can't see args on rule refs.
*/
@Override
public Attribute resolveToAttribute(String x, String y, ActionAST node) {
if ( rule.name.equals(x) ) { // x is this rule?
return rule.resolveToAttribute(x, y, node);
}
if ( tokenRefs.get(x)!=null ) { // token ref in this alt?
return rule.getPredefinedScope(LabelType.TOKEN_LABEL).get(y);
}
if ( ruleRefs.get(x)!=null ) { // rule ref in this alt?
// look up rule, ask it to resolve y (must be retval or predefined)
return rule.g.getRule(x).resolveRetvalOrProperty(y);
}
LabelElementPair anyLabelDef = getAnyLabelDef(x);
if ( anyLabelDef!=null && anyLabelDef.type==LabelType.RULE_LABEL ) {
return rule.g.getRule(anyLabelDef.element.getText()).resolveRetvalOrProperty(y);
}
else if ( anyLabelDef!=null ) {
AttributeDict scope = rule.getPredefinedScope(anyLabelDef.type);
if (scope == null) {
return null;
}
return scope.get(y);
}
return null;
}
@Override
public boolean resolvesToLabel(String x, ActionAST node) {
LabelElementPair anyLabelDef = getAnyLabelDef(x);
return anyLabelDef!=null &&
(anyLabelDef.type==LabelType.TOKEN_LABEL ||
anyLabelDef.type==LabelType.RULE_LABEL);
}
@Override
public boolean resolvesToListLabel(String x, ActionAST node) {
LabelElementPair anyLabelDef = getAnyLabelDef(x);
return anyLabelDef!=null &&
(anyLabelDef.type==LabelType.RULE_LIST_LABEL ||
anyLabelDef.type==LabelType.TOKEN_LIST_LABEL);
}
public LabelElementPair getAnyLabelDef(String x) {
List labels = labelDefs.get(x);
if ( labels!=null ) return labels.get(0);
return null;
}
/** x can be ruleref or rule label. */
public Rule resolveToRule(String x) {
if ( ruleRefs.get(x)!=null ) return rule.g.getRule(x);
LabelElementPair anyLabelDef = getAnyLabelDef(x);
if ( anyLabelDef!=null && anyLabelDef.type==LabelType.RULE_LABEL ) {
return rule.g.getRule(anyLabelDef.element.getText());
}
if ( x.equals(rule.name) ) return rule;
return null;
}
}