postgresql/src/backend/replication/repl_gram.y
Magnus Hagander fcd810c69a Use a lexer and grammar for parsing walsender commands
Makes it easier to parse mainly the BASE_BACKUP command
with it's options, and avoids having to manually deal
with quoted identifiers in the label (previously broken),
and makes it easier to add new commands and options in
the future.

In passing, refactor the case statement in the walsender
to put each command in it's own function.
2011-01-14 16:30:33 +01:00

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%{
/*-------------------------------------------------------------------------
*
* repl_gram.y - Parser for the replication commands
*
* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/replication/repl_gram.y
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "replication/replnodes.h"
#include "replication/walsender.h"
/* Result of the parsing is returned here */
Node *replication_parse_result;
/* Location tracking support --- simpler than bison's default */
#define YYLLOC_DEFAULT(Current, Rhs, N) \
do { \
if (N) \
(Current) = (Rhs)[1]; \
else \
(Current) = (Rhs)[0]; \
} while (0)
/*
* Bison doesn't allocate anything that needs to live across parser calls,
* so we can easily have it use palloc instead of malloc. This prevents
* memory leaks if we error out during parsing. Note this only works with
* bison >= 2.0. However, in bison 1.875 the default is to use alloca()
* if possible, so there's not really much problem anyhow, at least if
* you're building with gcc.
*/
#define YYMALLOC palloc
#define YYFREE pfree
#define parser_yyerror(msg) replication_yyerror(msg, yyscanner)
#define parser_errposition(pos) replication_scanner_errposition(pos)
%}
%expect 0
%name-prefix="replication_yy"
%union {
char *str;
bool boolval;
XLogRecPtr recptr;
Node *node;
}
/* Non-keyword tokens */
%token <str> SCONST
%token <recptr> RECPTR
/* Keyword tokens. */
%token K_BASE_BACKUP
%token K_IDENTIFY_SYSTEM
%token K_LABEL
%token K_PROGRESS
%token K_START_REPLICATION
%type <node> command
%type <node> base_backup start_replication identify_system
%type <boolval> opt_progress
%type <str> opt_label
%%
firstcmd: command opt_semicolon
{
replication_parse_result = $1;
}
;
opt_semicolon: ';'
| /* EMPTY */
;
command:
identify_system
| base_backup
| start_replication
;
/*
* IDENTIFY_SYSTEM
*/
identify_system:
K_IDENTIFY_SYSTEM
{
$$ = (Node *) makeNode(IdentifySystemCmd);
}
;
/*
* BASE_BACKUP [LABEL <label>] [PROGRESS]
*/
base_backup:
K_BASE_BACKUP opt_label opt_progress
{
BaseBackupCmd *cmd = (BaseBackupCmd *) makeNode(BaseBackupCmd);
cmd->label = $2;
cmd->progress = $3;
$$ = (Node *) cmd;
}
;
opt_label: K_LABEL SCONST { $$ = $2; }
| /* EMPTY */ { $$ = NULL; }
;
opt_progress: K_PROGRESS { $$ = true; }
| /* EMPTY */ { $$ = false; }
;
/*
* START_REPLICATION %X/%X
*/
start_replication:
K_START_REPLICATION RECPTR
{
StartReplicationCmd *cmd;
cmd = makeNode(StartReplicationCmd);
cmd->startpoint = $2;
$$ = (Node *) cmd;
}
;
%%
#include "repl_scanner.c"