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Implement dollar-quoting in the backend lexer and psql. Documentation

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is still lacking, as is support in plpgsql and other places, but this is
the basic feature.  Patch by Andrew Dunstan, some tweaking by Tom Lane.
Also, enable %option nodefault in these two lexers, and patch some gaps
revealed thereby.
REL8_0_STABLE
Tom Lane 22 years ago
parent 1f87d79142
commit 58e705320e
4 changed files with 131 additions and 12 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 60
      src/backend/parser/scan.l
  2. 6
      src/bin/psql/prompt.c
  3. 3
      src/bin/psql/prompt.h
  4. 74
      src/bin/psql/psqlscan.l

60
src/backend/parser/scan.l
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@ -10,7 +10,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.114 2004/02/21 00:34:52 tgl Exp $
* $PostgreSQL: pgsql/src/backend/parser/scan.l,v 1.115 2004/02/24 21:45:18 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -37,6 +37,7 @@
extern YYSTYPE yylval;
static int xcdepth = 0; /* depth of nesting in slash-star comments */
static char *dolqstart; /* current $foo$ quote start string */
/*
* literalbuf is used to accumulate literal values when multiple rules
@ -74,6 +75,7 @@ unsigned char unescape_single_char(unsigned char c);
%option 8bit
%option never-interactive
%option nodefault
%option nounput
%option noyywrap
%option prefix="base_yy"
@ -94,6 +96,7 @@ unsigned char unescape_single_char(unsigned char c);
* <xd> delimited identifiers (double-quoted identifiers)
* <xh> hexadecimal numeric string
* <xq> quoted strings
* <xdolq> $foo$ quoted strings
*/
%x xb
@ -101,6 +104,7 @@ unsigned char unescape_single_char(unsigned char c);
%x xd
%x xh
%x xq
%x xdolq
/*
* In order to make the world safe for Windows and Mac clients as well as
@ -175,6 +179,17 @@ xqescape [\\][^0-7]
xqoctesc [\\][0-7]{1,3}
xqcat {quote}{whitespace_with_newline}{quote}
/* $foo$ style quotes ("dollar quoting")
* The quoted string starts with $foo$ where "foo" is an optional string
* in the form of an identifier, except that it may not contain "$",
* and extends to the first occurrence of an identical string.
* There is *no* processing of the quoted text.
*/
dolq_start [A-Za-z\200-\377_]
dolq_cont [A-Za-z\200-\377_0-9]
dolqdelim \$({dolq_start}{dolq_cont}*)?\$
dolqinside [^$]+
/* Double quote
* Allows embedded spaces and other special characters into identifiers.
*/
@ -242,7 +257,8 @@ param \${integer}
other .
/*
* Quoted strings must allow some special characters such as single-quote
* Dollar quoted strings are totally opaque, and no escaping is done on them.
* Other quoted strings must allow some special characters such as single-quote
* and newline.
* Embedded single-quotes are implemented both in the SQL standard
* style of two adjacent single quotes "''" and in the Postgres/Java style
@ -388,8 +404,46 @@ other .
<xq>{xqcat} {
/* ignore */
}
<xq>. {
/* This is only needed for \ just before EOF */
addlitchar(yytext[0]);
}
<xq><<EOF>> { yyerror("unterminated quoted string"); }
{dolqdelim} {
token_start = yytext;
dolqstart = pstrdup(yytext);
BEGIN(xdolq);
startlit();
}
<xdolq>{dolqdelim} {
if (strcmp(yytext, dolqstart) == 0)
{
pfree(dolqstart);
BEGIN(INITIAL);
yylval.str = litbufdup();
return SCONST;
}
else
{
/*
* When we fail to match $...$ to dolqstart, transfer
* the $... part to the output, but put back the final
* $ for rescanning. Consider $delim$...$junk$delim$
*/
addlit(yytext, yyleng-1);
yyless(yyleng-1);
}
}
<xdolq>{dolqinside} {
addlit(yytext, yyleng);
}
<xdolq>. {
/* This is only needed for $ inside the quoted text */
addlitchar(yytext[0]);
}
<xdolq><<EOF>> { yyerror("unterminated dollar-quoted string"); }
{xdstart} {
token_start = yytext;
BEGIN(xd);
@ -407,7 +461,7 @@ other .
yylval.str = ident;
return IDENT;
}
<xd>{xddouble} {
<xd>{xddouble} {
addlitchar('"');
}
<xd>{xdinside} {

6
src/bin/psql/prompt.c
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@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2003, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/bin/psql/prompt.c,v 1.34 2004/01/25 03:07:22 neilc Exp $
* $PostgreSQL: pgsql/src/bin/psql/prompt.c,v 1.35 2004/02/24 21:45:18 tgl Exp $
*/
#include "postgres_fe.h"
#include "prompt.h"
@ -85,6 +85,7 @@ get_prompt(promptStatus_t status)
case PROMPT_CONTINUE:
case PROMPT_SINGLEQUOTE:
case PROMPT_DOUBLEQUOTE:
case PROMPT_DOLLARQUOTE:
case PROMPT_COMMENT:
case PROMPT_PAREN:
prompt_name = "PROMPT2";
@ -199,6 +200,9 @@ get_prompt(promptStatus_t status)
case PROMPT_DOUBLEQUOTE:
buf[0] = '"';
break;
case PROMPT_DOLLARQUOTE:
buf[0] = '$';
break;
case PROMPT_COMMENT:
buf[0] = '*';
break;

3
src/bin/psql/prompt.h
Unescape View File

@ -3,7 +3,7 @@
*
* Copyright (c) 2000-2003, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/bin/psql/prompt.h,v 1.13 2003/11/29 19:52:07 pgsql Exp $
* $PostgreSQL: pgsql/src/bin/psql/prompt.h,v 1.14 2004/02/24 21:45:18 tgl Exp $
*/
#ifndef PROMPT_H
#define PROMPT_H
@ -15,6 +15,7 @@ typedef enum _promptStatus
PROMPT_COMMENT,
PROMPT_SINGLEQUOTE,
PROMPT_DOUBLEQUOTE,
PROMPT_DOLLARQUOTE,
PROMPT_PAREN,
PROMPT_COPY
} promptStatus_t;

74
src/bin/psql/psqlscan.l
Unescape View File

@ -31,7 +31,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/bin/psql/psqlscan.l,v 1.1 2004/02/19 19:40:09 tgl Exp $
* $PostgreSQL: pgsql/src/bin/psql/psqlscan.l,v 1.2 2004/02/24 21:45:18 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -92,6 +92,7 @@ typedef struct PsqlScanStateData
int start_state; /* saved YY_START */
int paren_depth; /* depth of nesting in parentheses */
int xcdepth; /* depth of nesting in slash-star comments */
char *dolqstart; /* current $foo$ quote start string */
} PsqlScanStateData;
static PsqlScanState cur_state; /* current state while active */
@ -123,6 +124,7 @@ static void emit(const char *txt, int len);
%option 8bit
%option never-interactive
%option nodefault
%option nounput
%option noyywrap
@ -151,6 +153,7 @@ static void emit(const char *txt, int len);
* <xd> delimited identifiers (double-quoted identifiers)
* <xh> hexadecimal numeric string
* <xq> quoted strings
* <xdolq> $foo$ quoted strings
*/
%x xb
@ -158,6 +161,7 @@ static void emit(const char *txt, int len);
%x xd
%x xh
%x xq
%x xdolq
/* Additional exclusive states for psql only: lex backslash commands */
%x xslashcmd
%x xslasharg
@ -241,6 +245,17 @@ xqescape [\\][^0-7]
xqoctesc [\\][0-7]{1,3}
xqcat {quote}{whitespace_with_newline}{quote}
/* $foo$ style quotes ("dollar quoting")
* The quoted string starts with $foo$ where "foo" is an optional string
* in the form of an identifier, except that it may not contain "$",
* and extends to the first occurrence of an identical string.
* There is *no* processing of the quoted text.
*/
dolq_start [A-Za-z\200-\377_]
dolq_cont [A-Za-z\200-\377_0-9]
dolqdelim \$({dolq_start}{dolq_cont}*)?\$
dolqinside [^$]+
/* Double quote
* Allows embedded spaces and other special characters into identifiers.
*/
@ -308,7 +323,8 @@ param \${integer}
other .
/*
* Quoted strings must allow some special characters such as single-quote
* Dollar quoted strings are totally opaque, and no escaping is done on them.
* Other quoted strings must allow some special characters such as single-quote
* and newline.
* Embedded single-quotes are implemented both in the SQL standard
* style of two adjacent single quotes "''" and in the Postgres/Java style
@ -427,6 +443,41 @@ other .
<xq>{xqcat} {
ECHO;
}
<xq>. {
/* This is only needed for \ just before EOF */
ECHO;
}
{dolqdelim} {
cur_state->dolqstart = pg_strdup(yytext);
BEGIN(xdolq);
ECHO;
}
<xdolq>{dolqdelim} {
if (strcmp(yytext, cur_state->dolqstart) == 0)
{
free(cur_state->dolqstart);
cur_state->dolqstart = NULL;
BEGIN(INITIAL);
}
else
{
/*
* When we fail to match $...$ to dolqstart, transfer
* the $... part to the output, but put back the final
* $ for rescanning. Consider $delim$...$junk$delim$
*/
yyless(yyleng-1);
}
ECHO;
}
<xdolq>{dolqinside} {
ECHO;
}
<xdolq>. {
/* This is only needed for $ inside the quoted text */
ECHO;
}
{xdstart} {
BEGIN(xd);
@ -436,7 +487,7 @@ other .
BEGIN(INITIAL);
ECHO;
}
<xd>{xddouble} {
<xd>{xddouble} {
ECHO;
}
<xd>{xdinside} {
@ -754,7 +805,7 @@ other .
"\\". { emit(yytext + 1, 1); }
{other} { ECHO; }
{other}|\n { ECHO; }
}
@ -766,7 +817,7 @@ other .
"`" { return LEXRES_OK; }
{other} { ECHO; }
{other}|\n { ECHO; }
}
@ -811,7 +862,7 @@ other .
BEGIN(xslashdefaultarg);
}
{other} { ECHO; }
{other}|\n { ECHO; }
}
@ -833,7 +884,7 @@ other .
"\\\\" { return LEXRES_OK; }
{other} {
{other}|\n {
yyless(0);
return LEXRES_OK;
}
@ -865,6 +916,8 @@ psql_scan_destroy(PsqlScanState state)
{
psql_scan_finish(state);
psql_scan_reset(state);
free(state);
}
@ -1008,6 +1061,10 @@ psql_scan(PsqlScanState state,
result = PSCAN_INCOMPLETE;
*prompt = PROMPT_SINGLEQUOTE;
break;
case xdolq:
result = PSCAN_INCOMPLETE;
*prompt = PROMPT_DOLLARQUOTE;
break;
default:
/* can't get here */
fprintf(stderr, "invalid YY_START\n");
@ -1082,6 +1139,9 @@ psql_scan_reset(PsqlScanState state)
state->start_state = INITIAL;
state->paren_depth = 0;
state->xcdepth = 0; /* not really necessary */
if (state->dolqstart)
free(state->dolqstart);
state->dolqstart = NULL;
}
/*

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