postgresql/src/backend/parser
Tom Lane 9e138a401d Fix ecpg bugs caused by missing semicolons in the backend grammar.
The Bison documentation clearly states that a semicolon is required
after every grammar rule, and our scripts that generate ecpg's
grammar from the backend's implicitly assumed this is true.  But it
turns out that only ancient versions of Bison actually enforce that.
There have been a couple of rules without trailing semicolons in
gram.y for some time, and as a consequence, ecpg's grammar was faulty
and produced wrong output for the affected statements.

To fix, add the missing semis, and add some cross-checks to ecpg's
scripts so that they'll bleat if we mess this up again.

The cases that were broken were:
* "SET variable = DEFAULT" (but not "SET variable TO DEFAULT"),
  as well as allied syntaxes such as ALTER SYSTEM SET ... DEFAULT.
  These produced syntactically invalid output that the server
  would reject.
* Multiple type names in DROP TYPE/DOMAIN commands.  Only the
  first type name would be listed in the emitted command.

Per report from Daisuke Higuchi.  Back-patch to all supported versions.

Discussion: https://postgr.es/m/1803D792815FC24D871C00D17AE95905DB51CE@g01jpexmbkw24
2019-02-24 12:51:50 -05:00
..
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
Makefile Revert MERGE patch 2018-04-12 11:22:56 +01:00
README Move keywords.c/kwlookup.c into src/common/. 2016-03-23 20:22:08 -04:00
analyze.c Add collation assignment to CALL statement 2019-02-07 08:25:47 +01:00
check_keywords.pl Update copyright for 2019 2019-01-02 12:44:25 -05:00
gram.y Fix ecpg bugs caused by missing semicolons in the backend grammar. 2019-02-24 12:51:50 -05:00
parse_agg.c Refactor planner's header files. 2019-01-29 15:48:51 -05:00
parse_clause.c Refactor planner's header files. 2019-01-29 15:48:51 -05:00
parse_coerce.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_collate.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_cte.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_enr.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_expr.c Renaming for new subscripting mechanism 2019-02-01 12:50:32 -03:00
parse_func.c Allow generalized expression syntax for partition bounds 2019-01-25 11:28:49 +01:00
parse_node.c Renaming for new subscripting mechanism 2019-02-01 12:50:32 -03:00
parse_oper.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_param.c Update copyright for 2019 2019-01-02 12:44:25 -05:00
parse_relation.c Allow RECORD and RECORD[] to be specified in function coldeflists. 2019-01-30 19:25:33 -05:00
parse_target.c Renaming for new subscripting mechanism 2019-02-01 12:50:32 -03:00
parse_type.c More unconstify use 2019-02-13 11:50:16 +01:00
parse_utilcmd.c Refactor planner's header files. 2019-01-29 15:48:51 -05:00
parser.c Replace the data structure used for keyword lookup. 2019-01-06 17:02:57 -05:00
scan.l Replace the data structure used for keyword lookup. 2019-01-06 17:02:57 -05:00
scansup.c Update copyright for 2019 2019-01-02 12:44:25 -05:00

README

src/backend/parser/README

Parser
======

This directory does more than tokenize and parse SQL queries.  It also
creates Query structures for the various complex queries that are passed
to the optimizer and then executor.

parser.c	things start here
scan.l		break query into tokens
scansup.c	handle escapes in input strings
gram.y		parse the tokens and produce a "raw" parse tree
analyze.c	top level of parse analysis for optimizable queries
parse_agg.c	handle aggregates, like SUM(col1),  AVG(col2), ...
parse_clause.c	handle clauses like WHERE, ORDER BY, GROUP BY, ...
parse_coerce.c	handle coercing expressions to different data types
parse_collate.c	assign collation information in completed expressions
parse_cte.c	handle Common Table Expressions (WITH clauses)
parse_expr.c	handle expressions like col, col + 3, x = 3 or x = 4
parse_func.c	handle functions, table.column and column identifiers
parse_node.c	create nodes for various structures
parse_oper.c	handle operators in expressions
parse_param.c	handle Params (for the cases used in the core backend)
parse_relation.c support routines for tables and column handling
parse_target.c	handle the result list of the query
parse_type.c	support routines for data type handling
parse_utilcmd.c	parse analysis for utility commands (done at execution time)

See also src/common/keywords.c, which contains the table of standard
keywords and the keyword lookup function.  We separated that out because
various frontend code wants to use it too.