forgejo/vendor/github.com/pingcap/tidb/parser/yy_parser.go

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// Copyright 2015 PingCAP, Inc.
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package parser
import (
"regexp"
"strings"
"github.com/juju/errors"
"github.com/pingcap/tidb/ast"
"github.com/pingcap/tidb/mysql"
"github.com/pingcap/tidb/terror"
)
// Error instances.
var (
ErrSyntax = terror.ClassParser.New(CodeSyntaxErr, "syntax error")
)
// Error codes.
const (
CodeSyntaxErr terror.ErrCode = 1
)
var (
specCodePattern = regexp.MustCompile(`\/\*!(M?[0-9]{5,6})?([^*]|\*+[^*/])*\*+\/`)
specCodeStart = regexp.MustCompile(`^\/\*!(M?[0-9]{5,6} )?[ \t]*`)
specCodeEnd = regexp.MustCompile(`[ \t]*\*\/$`)
)
func trimComment(txt string) string {
txt = specCodeStart.ReplaceAllString(txt, "")
return specCodeEnd.ReplaceAllString(txt, "")
}
// See: http://dev.mysql.com/doc/refman/5.7/en/comments.html
// Convert "/*!VersionNumber MySQL-specific-code */" to "MySQL-specific-code".
// TODO: Find a better way:
// 1. RegExpr is slow.
// 2. Handle nested comment.
func handleMySQLSpecificCode(sql string) string {
if strings.Index(sql, "/*!") == -1 {
// Fast way to check if text contains MySQL-specific code.
return sql
}
// SQL text contains MySQL-specific code. We should convert it to normal SQL text.
return specCodePattern.ReplaceAllStringFunc(sql, trimComment)
}
// Parse parses a query string to raw ast.StmtNode.
// If charset or collation is "", default charset and collation will be used.
func Parse(sql, charset, collation string) ([]ast.StmtNode, error) {
if charset == "" {
charset = mysql.DefaultCharset
}
if collation == "" {
collation = mysql.DefaultCollationName
}
sql = handleMySQLSpecificCode(sql)
l := NewLexer(sql)
l.SetCharsetInfo(charset, collation)
yyParse(l)
if len(l.Errors()) != 0 {
return nil, errors.Trace(l.Errors()[0])
}
return l.Stmts(), nil
}
// ParseOneStmt parses a query and returns an ast.StmtNode.
// The query must have one statement, otherwise ErrSyntax is returned.
func ParseOneStmt(sql, charset, collation string) (ast.StmtNode, error) {
stmts, err := Parse(sql, charset, collation)
if err != nil {
return nil, errors.Trace(err)
}
if len(stmts) != 1 {
return nil, ErrSyntax
}
return stmts[0], nil
}