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io.trino.sql.parser.SqlParser Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.trino.sql.parser;
import io.trino.grammar.sql.SqlBaseBaseListener;
import io.trino.grammar.sql.SqlBaseLexer;
import io.trino.grammar.sql.SqlBaseParser;
import io.trino.sql.tree.DataType;
import io.trino.sql.tree.Expression;
import io.trino.sql.tree.FunctionSpecification;
import io.trino.sql.tree.Node;
import io.trino.sql.tree.NodeLocation;
import io.trino.sql.tree.PathSpecification;
import io.trino.sql.tree.RowPattern;
import io.trino.sql.tree.Statement;
import org.antlr.v4.runtime.ANTLRErrorListener;
import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CommonToken;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.DefaultErrorStrategy;
import org.antlr.v4.runtime.InputMismatchException;
import org.antlr.v4.runtime.Parser;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.atn.PredictionMode;
import org.antlr.v4.runtime.misc.Pair;
import org.antlr.v4.runtime.tree.TerminalNode;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;
import java.util.function.BiConsumer;
import java.util.function.Function;
import static java.util.Objects.requireNonNull;
public class SqlParser
{
private static final ANTLRErrorListener LEXER_ERROR_LISTENER = new BaseErrorListener()
{
@Override
public void syntaxError(Recognizer recognizer, Object offendingSymbol, int line, int charPositionInLine, String message, RecognitionException e)
{
throw new ParsingException(message, e, line, charPositionInLine + 1);
}
};
private static final BiConsumer DEFAULT_PARSER_INITIALIZER = (SqlBaseLexer lexer, SqlBaseParser parser) -> {};
private static final ErrorHandler PARSER_ERROR_HANDLER = ErrorHandler.builder()
.specialRule(SqlBaseParser.RULE_expression, "")
.specialRule(SqlBaseParser.RULE_booleanExpression, "")
.specialRule(SqlBaseParser.RULE_valueExpression, "")
.specialRule(SqlBaseParser.RULE_primaryExpression, "")
.specialRule(SqlBaseParser.RULE_predicate, "")
.specialRule(SqlBaseParser.RULE_identifier, "")
.specialRule(SqlBaseParser.RULE_string, "")
.specialRule(SqlBaseParser.RULE_query, "")
.specialRule(SqlBaseParser.RULE_type, "")
.specialToken(SqlBaseLexer.INTEGER_VALUE, "")
.build();
private final BiConsumer initializer;
public SqlParser()
{
this(DEFAULT_PARSER_INITIALIZER);
}
public SqlParser(BiConsumer initializer)
{
this.initializer = requireNonNull(initializer, "initializer is null");
}
public Statement createStatement(String sql)
{
return (Statement) invokeParser("statement", sql, SqlBaseParser::singleStatement);
}
public Statement createStatement(String sql, NodeLocation location)
{
return (Statement) invokeParser("statement", sql, Optional.ofNullable(location), SqlBaseParser::singleStatement);
}
public Expression createExpression(String expression)
{
return (Expression) invokeParser("expression", expression, SqlBaseParser::standaloneExpression);
}
public DataType createType(String expression)
{
return (DataType) invokeParser("type", expression, SqlBaseParser::standaloneType);
}
public PathSpecification createPathSpecification(String expression)
{
return (PathSpecification) invokeParser("path specification", expression, SqlBaseParser::standalonePathSpecification);
}
public RowPattern createRowPattern(String pattern)
{
return (RowPattern) invokeParser("row pattern", pattern, SqlBaseParser::standaloneRowPattern);
}
public FunctionSpecification createFunctionSpecification(String sql)
{
return (FunctionSpecification) invokeParser("function specification", sql, SqlBaseParser::standaloneFunctionSpecification);
}
private Node invokeParser(String name, String sql, Function parseFunction)
{
return invokeParser(name, sql, Optional.empty(), parseFunction);
}
private Node invokeParser(String name, String sql, Optional location, Function parseFunction)
{
try {
SqlBaseLexer lexer = new SqlBaseLexer(CharStreams.fromString(sql));
CommonTokenStream tokenStream = new CommonTokenStream(lexer);
SqlBaseParser parser = new SqlBaseParser(tokenStream);
initializer.accept(lexer, parser);
// Override the default error strategy to not attempt inserting or deleting a token.
// Otherwise, it messes up error reporting
parser.setErrorHandler(new DefaultErrorStrategy()
{
@Override
public Token recoverInline(Parser recognizer)
throws RecognitionException
{
if (nextTokensContext == null) {
throw new InputMismatchException(recognizer);
}
throw new InputMismatchException(recognizer, nextTokensState, nextTokensContext);
}
});
parser.addParseListener(new PostProcessor(Arrays.asList(parser.getRuleNames()), parser));
lexer.removeErrorListeners();
lexer.addErrorListener(LEXER_ERROR_LISTENER);
parser.removeErrorListeners();
parser.addErrorListener(PARSER_ERROR_HANDLER);
ParserRuleContext tree;
try {
try {
// first, try parsing with potentially faster SLL mode
parser.getInterpreter().setPredictionMode(PredictionMode.SLL);
tree = parseFunction.apply(parser);
}
catch (ParsingException ex) {
// if we fail, parse with LL mode
tokenStream.seek(0); // rewind input stream
parser.reset();
parser.getInterpreter().setPredictionMode(PredictionMode.LL);
tree = parseFunction.apply(parser);
}
}
catch (ParsingException e) {
location.ifPresent(statementLocation -> {
int line = statementLocation.getLineNumber();
int column = statementLocation.getColumnNumber();
throw new ParsingException(
e.getErrorMessage(),
(RecognitionException) e.getCause(),
e.getLineNumber() + line - 1,
e.getColumnNumber() + (line == 1 ? column : 0));
});
throw e;
}
return new AstBuilder(location).visit(tree);
}
catch (StackOverflowError e) {
throw new ParsingException(name + " is too large (stack overflow while parsing)", location.orElse(new NodeLocation(1, 1)));
}
}
private static class PostProcessor
extends SqlBaseBaseListener
{
private final List ruleNames;
private final SqlBaseParser parser;
public PostProcessor(List ruleNames, SqlBaseParser parser)
{
this.ruleNames = ruleNames;
this.parser = parser;
}
@Override
public void exitQuotedIdentifier(SqlBaseParser.QuotedIdentifierContext context)
{
Token token = context.QUOTED_IDENTIFIER().getSymbol();
if (token.getText().length() == 2) { // empty identifier
throw new ParsingException("Zero-length delimited identifier not allowed", null, token.getLine(), token.getCharPositionInLine() + 1);
}
}
@Override
public void exitBackQuotedIdentifier(SqlBaseParser.BackQuotedIdentifierContext context)
{
Token token = context.BACKQUOTED_IDENTIFIER().getSymbol();
throw new ParsingException(
"backquoted identifiers are not supported; use double quotes to quote identifiers",
null,
token.getLine(),
token.getCharPositionInLine() + 1);
}
@Override
public void exitDigitIdentifier(SqlBaseParser.DigitIdentifierContext context)
{
Token token = context.DIGIT_IDENTIFIER().getSymbol();
throw new ParsingException(
"identifiers must not start with a digit; surround the identifier with double quotes",
null,
token.getLine(),
token.getCharPositionInLine() + 1);
}
@Override
public void exitNonReserved(SqlBaseParser.NonReservedContext context)
{
// we can't modify the tree during rule enter/exit event handling unless we're dealing with a terminal.
// Otherwise, ANTLR gets confused and fires spurious notifications.
if (!(context.getChild(0) instanceof TerminalNode)) {
int rule = ((ParserRuleContext) context.getChild(0)).getRuleIndex();
throw new AssertionError("nonReserved can only contain tokens. Found nested rule: " + ruleNames.get(rule));
}
// replace nonReserved words with IDENT tokens
context.getParent().removeLastChild();
Token token = (Token) context.getChild(0).getPayload();
Token newToken = new CommonToken(
new Pair<>(token.getTokenSource(), token.getInputStream()),
SqlBaseLexer.IDENTIFIER,
token.getChannel(),
token.getStartIndex(),
token.getStopIndex());
context.getParent().addChild(parser.createTerminalNode(context.getParent(), newToken));
}
}
}
