Package org.antlr.v4.semantics

Class SymbolChecks

java.lang.Object

org.antlr.v4.semantics.SymbolChecks

public class SymbolChecks
extends Object

Check for symbol problems; no side-effects. Inefficient to walk rules and such multiple times, but I like isolating all error checking outside of code that actually defines symbols etc... Side-effect: strip away redef'd rules.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Map<String,Set<String>>	actionScopeToActionNames
(package private) SymbolCollector	collector
ErrorManager	errMgr
(package private) Grammar	g
(package private) Map<String,Rule>	nameToRuleMap
protected final Set<String>	reservedNames
(package private) Set<String>	tokenIDs

Constructor Summary

Constructors

Constructor	Description
SymbolChecks(Grammar g, SymbolCollector collector)

Method Summary

Modifier and Type	Method	Description
void	checkActionRedefinitions(List<GrammarAST> actions)
protected void	checkDeclarationRuleConflicts(Rule r, AttributeDict attributes, Set<String> ruleNames, ErrorType errorType)
void	checkForAttributeConflicts(Rule r)
void	checkForLabelConflict(Rule r, GrammarAST labelID)
void	checkForLabelConflicts(Collection<Rule> rules)	Make sure a label doesn't conflict with another symbol.
void	checkForModeConflicts(Grammar g)
private void	checkForOverlap(Grammar g, Rule rule1, Rule rule2, List<String> firstTokenStringValues, List<String> secondTokenStringValues)	For same rule compare values from next index: TOKEN_WITH_SAME_VALUES: 'asdf' | 'asdf'; For different rules compare from start value: TOKEN1: 'asdf'; TOKEN2: 'asdf';
void	checkForQualifiedRuleIssues(Grammar g, List<GrammarAST> qualifiedRuleRefs)
private void	checkForTypeMismatch(Rule r, LabelElementPair prevLabelPair, LabelElementPair labelPair)
void	checkForUnreachableTokens(Grammar g)	Algorithm steps: 1.
private void	checkLabelPairs(Rule r, Map<String,LabelElementPair> labelNameSpace, List<LabelElementPair> pairs)
protected void	checkLocalConflictingDeclarations(Rule r, AttributeDict attributes, AttributeDict referenceAttributes, ErrorType errorType)
protected void	checkReservedNames(Collection<Rule> rules)
void	checkRuleArgs(Grammar g, List<GrammarAST> rulerefs)
private String	findAltLabelName(org.antlr.runtime.tree.CommonTree label)
private List<String>	getSingleTokenValues(Rule rule)	Returns .
void	process()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

g

Grammar g

collector

SymbolCollector collector

nameToRuleMap

Map<String,Rule> nameToRuleMap

tokenIDs

Set<String> tokenIDs

actionScopeToActionNames

Map<String,Set<String>> actionScopeToActionNames

errMgr

public ErrorManager errMgr

reservedNames

protected final Set<String> reservedNames

Constructor Details

SymbolChecks

public SymbolChecks(Grammar g,
 SymbolCollector collector)

Method Details

process

public void process()

checkActionRedefinitions

public void checkActionRedefinitions(List<GrammarAST> actions)

checkForLabelConflicts

public void checkForLabelConflicts(Collection<Rule> rules)

Make sure a label doesn't conflict with another symbol. Labels must not conflict with: rules, tokens, scope names, return values, parameters, and rule-scope dynamic attributes defined in surrounding rule. Also they must have same type for repeated defs.

checkLabelPairs

private void checkLabelPairs(Rule r,
 Map<String,LabelElementPair> labelNameSpace,
 List<LabelElementPair> pairs)

findAltLabelName

private String findAltLabelName(org.antlr.runtime.tree.CommonTree label)

checkForTypeMismatch

private void checkForTypeMismatch(Rule r,
 LabelElementPair prevLabelPair,
 LabelElementPair labelPair)

checkForLabelConflict

public void checkForLabelConflict(Rule r,
 GrammarAST labelID)

checkForAttributeConflicts

public void checkForAttributeConflicts(Rule r)

checkDeclarationRuleConflicts

protected void checkDeclarationRuleConflicts(@NotNull
 Rule r,
 @Nullable
 AttributeDict attributes,
 @NotNull
 Set<String> ruleNames,
 @NotNull
 ErrorType errorType)

checkLocalConflictingDeclarations

protected void checkLocalConflictingDeclarations(@NotNull
 Rule r,
 @Nullable
 AttributeDict attributes,
 @Nullable
 AttributeDict referenceAttributes,
 @NotNull
 ErrorType errorType)

checkReservedNames

protected void checkReservedNames(@NotNull
 Collection<Rule> rules)

checkForModeConflicts

public void checkForModeConflicts(Grammar g)

checkForUnreachableTokens

public void checkForUnreachableTokens(Grammar g)

Algorithm steps: 1. Collect all simple string literals (i.e. 'asdf', 'as' 'df', but not [a-z]+, 'a'..'z') for all lexer rules in each mode except of autogenerated tokens (getSingleTokenValues(org.antlr.v4.tool.Rule)) 2. Compare every string literal with each other (checkForOverlap(org.antlr.v4.tool.Grammar, org.antlr.v4.tool.Rule, org.antlr.v4.tool.Rule, java.util.List<java.lang.String>, java.util.List<java.lang.String>)) and throw TOKEN_UNREACHABLE warning if the same string found. Complexity: O(m * n^2 / 2), approximately equals to O(n^2) where m - number of modes, n - average number of lexer rules per mode. See also testUnreachableTokens unit test for details.

getSingleTokenValues

private List<String> getSingleTokenValues(Rule rule)

Returns . list of simple string literals for rule

Returns:

checkForOverlap

private void checkForOverlap(Grammar g,
 Rule rule1,
 Rule rule2,
 List<String> firstTokenStringValues,
 List<String> secondTokenStringValues)

For same rule compare values from next index: TOKEN_WITH_SAME_VALUES: 'asdf' | 'asdf'; For different rules compare from start value: TOKEN1: 'asdf'; TOKEN2: 'asdf';

checkRuleArgs

public void checkRuleArgs(Grammar g,
 List<GrammarAST> rulerefs)

checkForQualifiedRuleIssues

public void checkForQualifiedRuleIssues(Grammar g,
 List<GrammarAST> qualifiedRuleRefs)