mirror of
https://github.com/zebrajr/postgres.git
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fbd26d6984
took some rejiggering of typename and ACL parsing, as well as moving parse_analyze call out of parser(). Restructure postgres.c processing so that parse analysis and rewrite are skipped when in abort-transaction state. Only COMMIT and ABORT statements will be processed beyond the raw parser() phase. This addresses problem of parser failing with database access errors while in aborted state (see pghackers discussions around 7/28/00). Also fix some bugs with COMMIT/ABORT statements appearing in the middle of a single query input string. Function, operator, and aggregate arguments/results can now use full TypeName production, in particular foo[] for array types. DROP OPERATOR and COMMENT ON OPERATOR were broken for unary operators. Allow CREATE AGGREGATE to accept unquoted numeric constants for initcond.
121 lines
2.8 KiB
C
121 lines
2.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* parser.c
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* Main entry point/driver for PostgreSQL grammar
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*
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* Note that the grammar is not allowed to perform any table access
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* (since we need to be able to do basic parsing even while inside an
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* aborted transaction). Therefore, the data structures returned by
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* the grammar are "raw" parsetrees that still need to be analyzed by
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* parse_analyze.
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*
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*
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* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/parser.c,v 1.47 2000/10/07 00:58:17 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "nodes/parsenodes.h"
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#include "parser/gramparse.h"
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#include "parser/parse.h"
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#include "parser/parser.h"
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#include "parser/parse_expr.h"
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#if defined(FLEX_SCANNER)
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extern void DeleteBuffer(void);
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#endif /* FLEX_SCANNER */
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char *parseString; /* the char* which holds the string to be
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* parsed */
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List *parsetree; /* result of parsing is left here */
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static int lookahead_token; /* one-token lookahead */
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static bool have_lookahead; /* lookahead_token set? */
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/*
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* parser
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* Given a query in string form, and optionally info about
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* parameter types, do lexical and syntactic analysis.
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*
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* Returns a list of raw (un-analyzed) parse trees.
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*/
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List *
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parser(char *str, Oid *typev, int nargs)
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{
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int yyresult;
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parseString = str;
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parsetree = NIL; /* in case parser forgets to set it */
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have_lookahead = false;
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scanner_init();
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parser_init(typev, nargs);
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parse_expr_init();
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yyresult = yyparse();
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#if defined(FLEX_SCANNER)
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DeleteBuffer();
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#endif /* FLEX_SCANNER */
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clearerr(stdin);
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if (yyresult) /* error */
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return NIL;
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return parsetree;
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}
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/*
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* Intermediate filter between parser and base lexer (base_yylex in scan.l).
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*
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* The filter is needed because in some cases SQL92 requires more than one
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* token lookahead. We reduce these cases to one-token lookahead by combining
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* tokens here, in order to keep the grammar LR(1).
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*
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* Using a filter is simpler than trying to recognize multiword tokens
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* directly in scan.l, because we'd have to allow for comments between the
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* words ...
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*/
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int
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yylex(void)
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{
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int cur_token;
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/* Get next token --- we might already have it */
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if (have_lookahead)
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{
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cur_token = lookahead_token;
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have_lookahead = false;
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}
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else
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cur_token = base_yylex();
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/* Do we need to look ahead for a possible multiword token? */
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switch (cur_token)
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{
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case UNION:
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/* UNION JOIN must be reduced to a single UNIONJOIN token */
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lookahead_token = base_yylex();
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if (lookahead_token == JOIN)
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cur_token = UNIONJOIN;
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else
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have_lookahead = true;
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break;
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default:
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break;
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}
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return cur_token;
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}
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