database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-16117 SP with a single FOR statement creates but further fails to load

Browse Source 
The code in the "sp_tail" rule in sql_yacc.yy always
used YYLIP->get_cpp_tok_start() as the start of the body,
and did not check for possible lookahead which happens
for keywords "FOR", "VALUES" and "WITH" for LALR(2)
resolution in Lex_input_stream::lex_token().

In case of the lookahead token presence,
get_tok_start_prev() should have been used instead
of get_cpp_tok_start() as the beginning of the SP body.

Change summary:

This patch hides the implementation of the lookahead
token completely inside Lex_input_stream.
The users of Lex_input_stream now just get token-by-token
transparently and should not care about lookahead any more.
Now external users of Lex_input_stream
are not aware of the lookahead token at all.

Change details:

- Moving Lex_input_stream::has_lookahead() into the "private" section.

- Removing Lex_input_stream::get_tok_start_prev() and
  Lex_input_stream::get_cpp_start_prev().

- Fixing the external code to call get_tok_start() and get_cpp_tok_start()
  in all places where get_tok_start_prev() and get_cpp_start_prev()
  where used.

- Adding a test for has_lookahead() right inside
  get_tok_start() and get_cpp_tok_start().
  If there is a lookahead token, these methods now
  return the position of the previous token automatically:

   const char *get_tok_start()
   {
     return has_lookahead() ? m_tok_start_prev : m_tok_start;
   }

   const char *get_cpp_tok_start()
   {
    return has_lookahead() ? m_cpp_tok_start_prev : m_cpp_tok_start;
   }

- Fixing the internal code inside Lex_input_stream methods
  to use m_tok_start and m_cpp_tok_start directly,
  instead of calling get_tok_start() and get_cpp_tok_start(),
  to make sure to access to the *current* token position
  (independently of a lookahead token presence).
This commit is contained in:
Alexander Barkov
2018-05-10 15:55:33 +04:00
parent 8b087c63b5
commit fc63c1e17a
6 changed files with 123 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
sql/sql_lex.h
View File

@ -2331,8 +2331,6 @@ private:
return (uint) ((m_ptr - m_tok_start) - 1);
}
public:
/**
Test if a lookahead token was already scanned by lex_token(),
for LALR(2) resolution.
@ -2342,6 +2340,8 @@ public:
return lookahead_token >= 0;
}
public:
/**
End of file indicator for the query text to parse.
@return true if there are no more characters to parse
@ -2372,7 +2372,7 @@ public:
/** Get the token start position, in the raw buffer. */
const char *get_tok_start()
{
return m_tok_start;
return has_lookahead() ? m_tok_start_prev : m_tok_start;
}
void set_cpp_tok_start(const char *pos)
@ -2386,28 +2386,16 @@ public:
return m_tok_end;
}
/** Get the previous token start position, in the raw buffer. */
const char *get_tok_start_prev()
{
return m_tok_start_prev;
}
/** Get the current stream pointer, in the raw buffer. */
const char *get_ptr()
{
return m_ptr;
}
/** Get the previus token start position, in the pre-processed buffer. */
const char *get_cpp_start_prev()
{
return m_cpp_tok_start_prev;
}
/** Get the token start position, in the pre-processed buffer. */
const char *get_cpp_tok_start()
{
return m_cpp_tok_start;
return has_lookahead() ? m_cpp_tok_start_prev : m_cpp_tok_start;
}
/** Get the token end position, in the pre-processed buffer. */