1f0de66ea2
Use the flex %option reentrant and the bison option %pure-parser to make the generated scanner and parser pure, reentrant, and thread-safe. Make the generated scanner use palloc() etc. instead of malloc() etc. Previously, we only used palloc() for the buffer, but flex would still use malloc() for its internal structures. As a result, there could be some small memory leaks in case of uncaught errors. (We do catch normal syntax errors as soft errors.) Now, all the memory is under palloc() control, so there are no more such issues. Simplify flex scan buffer management: Instead of constructing the buffer from pieces and then using yy_scan_buffer(), we can just use yy_scan_string(), which does the same thing internally. The previous code was necessary because we allocated the buffer with palloc() and the rest of the state was handled by malloc(). But this is no longer the case; everything is under palloc() now. (We could even get rid of the yylex_destroy() call and just let the memory context cleanup handle everything. But for now, we preserve the existing behavior.) Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Andreas Karlsson <andreas@proxel.se> Discussion: https://www.postgresql.org/message-id/flat/eb6faeac-2a8a-4b69-9189-c33c520e5b7b@eisentraut.org
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.