parser.c File Reference

#include "postgres_fe.h"
#include "preproc_extern.h"
#include "preproc.h"

Include dependency graph for parser.c:

Go to the source code of this file.

Functions
static bool	check_uescapechar (unsigned char escape)
static bool	ecpg_isspace (char ch)
int	filtered_base_yylex (void)

Variables
static bool	have_lookahead
static int	lookahead_token
static YYSTYPE	lookahead_yylval
static YYLTYPE	lookahead_yylloc
static char *	lookahead_yytext

Function Documentation

check_uescapechar()

static bool check_uescapechar ( unsigned char  escape )

static

Definition at line 206 of file parser.c.

References ecpg_isspace().

Referenced by filtered_base_yylex().

{
    if (isxdigit(escape)
        || escape == '+'
        || escape == '\''
        || escape == '"'
        || ecpg_isspace(escape))
        return false;
    else
        return true;
}

ecpg_isspace()

static bool ecpg_isspace ( char  ch )

static

Definition at line 222 of file parser.c.

Referenced by check_uescapechar().

{
    if (ch == ' ' ||
        ch == '\t' ||
        ch == '\n' ||
        ch == '\r' ||
        ch == '\f')
        return true;
    return false;
}

filtered_base_yylex()

int filtered_base_yylex

(

void

)

Definition at line 56 of file parser.c.

References base_yylex(), base_yytext, check_uescapechar(), ET_ERROR, have_lookahead, lookahead_token, lookahead_yylloc, lookahead_yylval, lookahead_yytext, mmerror(), next_token(), PARSE_ERROR, psprintf(), and YYLTYPE.

{
    int         cur_token;
    int         next_token;
    YYSTYPE     cur_yylval;
    YYLTYPE     cur_yylloc;
    char       *cur_yytext;

    /* Get next token --- we might already have it */
    if (have_lookahead)
    {
        cur_token = lookahead_token;
        base_yylval = lookahead_yylval;
        base_yylloc = lookahead_yylloc;
        base_yytext = lookahead_yytext;
        have_lookahead = false;
    }
    else
        cur_token = base_yylex();

    /*
     * If this token isn't one that requires lookahead, just return it.
     */
    switch (cur_token)
    {
        case NOT:
        case NULLS_P:
        case WITH:
        case UIDENT:
        case USCONST:
            break;
        default:
            return cur_token;
    }

    /* Save and restore lexer output variables around the call */
    cur_yylval = base_yylval;
    cur_yylloc = base_yylloc;
    cur_yytext = base_yytext;

    /* Get next token, saving outputs into lookahead variables */
    next_token = base_yylex();

    lookahead_token = next_token;
    lookahead_yylval = base_yylval;
    lookahead_yylloc = base_yylloc;
    lookahead_yytext = base_yytext;

    base_yylval = cur_yylval;
    base_yylloc = cur_yylloc;
    base_yytext = cur_yytext;

    have_lookahead = true;

    /* Replace cur_token if needed, based on lookahead */
    switch (cur_token)
    {
        case NOT:
            /* Replace NOT by NOT_LA if it's followed by BETWEEN, IN, etc */
            switch (next_token)
            {
                case BETWEEN:
                case IN_P:
                case LIKE:
                case ILIKE:
                case SIMILAR:
                    cur_token = NOT_LA;
                    break;
            }
            break;

        case NULLS_P:
            /* Replace NULLS_P by NULLS_LA if it's followed by FIRST or LAST */
            switch (next_token)
            {
                case FIRST_P:
                case LAST_P:
                    cur_token = NULLS_LA;
                    break;
            }
            break;

        case WITH:
            /* Replace WITH by WITH_LA if it's followed by TIME or ORDINALITY */
            switch (next_token)
            {
                case TIME:
                case ORDINALITY:
                    cur_token = WITH_LA;
                    break;
            }
            break;
        case UIDENT:
        case USCONST:
            /* Look ahead for UESCAPE */
            if (next_token == UESCAPE)
            {
                /* Yup, so get third token, which had better be SCONST */
                const char *escstr;

                /*
                 * Again save and restore lexer output variables around the
                 * call
                 */
                cur_yylval = base_yylval;
                cur_yylloc = base_yylloc;
                cur_yytext = base_yytext;

                /* Get third token */
                next_token = base_yylex();

                if (next_token != SCONST)
                    mmerror(PARSE_ERROR, ET_ERROR, "UESCAPE must be followed by a simple string literal");

                /*
                 * Save and check escape string, which the scanner returns
                 * with quotes
                 */
                escstr = base_yylval.str;
                if (strlen(escstr) != 3 || !check_uescapechar(escstr[1]))
                    mmerror(PARSE_ERROR, ET_ERROR, "invalid Unicode escape character");

                base_yylval = cur_yylval;
                base_yylloc = cur_yylloc;
                base_yytext = cur_yytext;

                /* Combine 3 tokens into 1 */
                base_yylval.str = psprintf("%s UESCAPE %s", base_yylval.str, escstr);

                /* Clear have_lookahead, thereby consuming all three tokens */
                have_lookahead = false;
            }

            if (cur_token == UIDENT)
                cur_token = IDENT;
            else if (cur_token == USCONST)
                cur_token = SCONST;
            break;
    }

    return cur_token;
}

Variable Documentation

have_lookahead

bool have_lookahead

static

Definition at line 28 of file parser.c.

Referenced by filtered_base_yylex().

lookahead_token

int lookahead_token

static

Definition at line 29 of file parser.c.

Referenced by filtered_base_yylex().

lookahead_yylloc

YYLTYPE lookahead_yylloc

static

Definition at line 31 of file parser.c.

Referenced by filtered_base_yylex().

lookahead_yylval

YYSTYPE lookahead_yylval

static

Definition at line 30 of file parser.c.

Referenced by filtered_base_yylex().

lookahead_yytext

char* lookahead_yytext

static

Definition at line 32 of file parser.c.

Referenced by filtered_base_yylex().