anonymous_namespace{item_strfunc.cc} Namespace Reference

Classes
class	Parse_error_anonymizer
	Error handler that wraps parse error messages, removes details and silences warnings. More...
class	Thd_parse_modifier
	Because it's not possible to disentangle the state of the parser from the THD, we have to destructively modify the current THD object in order to parse. More...

Functions
bool	parse (THD *thd, Item *statement_expr, String *statement_string)
	Parses a string and fills the token buffer. More...

Function Documentation

parse()

bool anonymous_namespace{item_strfunc.cc}::parse	(	THD *	thd,
		Item *	statement_expr,
		String *	statement_string
	)

Parses a string and fills the token buffer.

The parser function THD::sql_parser() is called directly instead of parse_sql(), as the latter assumes that it is called with the intent to record the statement in performance_schema and later execute it, neither of which is called for here. In fact we hardly need the parser to calculate a digest, since it is calculated from the token stream. There are only some corner cases where NULL is sometimes a literal and sometimes an operator, as in IS NULL, IS NOT NULL.

Parameters

thd	Session object used by the parser.
statement_expr	The expression that evaluates to something that can be parsed. Needed for error messages in case we don't want to disclose what it evaluates to.
statement_string	The non-NULL string resulting from evaluating statement_expr. The caller is preferred to do this as this function doesn't deal with NULL values.

Return values

true	Error.
false	All went well, the digest information is in THD::m_digest.