plperl.h

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/*-------------------------------------------------------------------------
 *
 * plperl.h
 *    Common include file for PL/Perl files
 *
 * This should be included _AFTER_ postgres.h and system include files, as
 * well as headers that could in turn include system headers.
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1995, Regents of the University of California
 *
 * src/pl/plperl/plperl.h
 */
 
#ifndef PL_PERL_H
#define PL_PERL_H
 
/* defines free() by way of system headers, so must be included before perl.h */
#include "mb/pg_wchar.h"
 
/*
 * Pull in Perl headers via a wrapper header, to control the scope of
 * the system_header pragma therein.
 */
#include "plperl_system.h"
 
/* declare routines from plperl.c for access by .xs files */
HV         *plperl_spi_exec(char *, int);
void        plperl_return_next(SV *);
SV         *plperl_spi_query(char *);
SV         *plperl_spi_fetchrow(char *);
SV         *plperl_spi_prepare(char *, int, SV **);
HV         *plperl_spi_exec_prepared(char *, HV *, int, SV **);
SV         *plperl_spi_query_prepared(char *, int, SV **);
void        plperl_spi_freeplan(char *);
void        plperl_spi_cursor_close(char *);
void        plperl_spi_commit(void);
void        plperl_spi_rollback(void);
char       *plperl_sv_to_literal(SV *, char *);
void        plperl_util_elog(int level, SV *msg);
 
 
/* helper functions */
 
/*
 * convert from utf8 to database encoding
 *
 * Returns a palloc'ed copy of the original string
 */
static inline char *
utf_u2e(char *utf8_str, size_t len)
{
    char       *ret;
 
    ret = pg_any_to_server(utf8_str, len, PG_UTF8);
 
    /* ensure we have a copy even if no conversion happened */
    if (ret == utf8_str)
        ret = pstrdup(ret);
 
    return ret;
}
 
/*
 * convert from database encoding to utf8
 *
 * Returns a palloc'ed copy of the original string
 */
static inline char *
utf_e2u(const char *str)
{
    char       *ret;
 
    ret = pg_server_to_any(str, strlen(str), PG_UTF8);
 
    /* ensure we have a copy even if no conversion happened */
    if (ret == str)
        ret = pstrdup(ret);
 
    return ret;
}
 
/*
 * Convert an SV to a char * in the current database encoding
 *
 * Returns a palloc'ed copy of the original string
 */
static inline char *
sv2cstr(SV *sv)
{
    dTHX;
    char       *val,
               *res;
    STRLEN      len;
 
    /*
     * get a utf8 encoded char * out of perl. *note* it may not be valid utf8!
     */
 
    /*
     * SvPVutf8() croaks nastily on certain things, like typeglobs and
     * readonly objects such as $^V. That's a perl bug - it's not supposed to
     * happen. To avoid crashing the backend, we make a copy of the sv before
     * passing it to SvPVutf8(). The copy is garbage collected when we're done
     * with it.
     */
    if (SvREADONLY(sv) ||
        isGV_with_GP(sv) ||
        (SvTYPE(sv) > SVt_PVLV && SvTYPE(sv) != SVt_PVFM))
        sv = newSVsv(sv);
    else
    {
        /*
         * increase the reference count so we can just SvREFCNT_dec() it when
         * we are done
         */
        SvREFCNT_inc_simple_void(sv);
    }
 
    /*
     * Request the string from Perl, in UTF-8 encoding; but if we're in a
     * SQL_ASCII database, just request the byte soup without trying to make
     * it UTF8, because that might fail.
     */
    if (GetDatabaseEncoding() == PG_SQL_ASCII)
        val = SvPV(sv, len);
    else
        val = SvPVutf8(sv, len);
 
    /*
     * Now convert to database encoding.  We use perl's length in the event we
     * had an embedded null byte to ensure we error out properly.
     */
    res = utf_u2e(val, len);
 
    /* safe now to garbage collect the new SV */
    SvREFCNT_dec(sv);
 
    return res;
}
 
/*
 * Create a new SV from a string assumed to be in the current database's
 * encoding.
 */
static inline SV *
cstr2sv(const char *str)
{
    dTHX;
    SV         *sv;
    char       *utf8_str;
 
    /* no conversion when SQL_ASCII */
    if (GetDatabaseEncoding() == PG_SQL_ASCII)
        return newSVpv(str, 0);
 
    utf8_str = utf_e2u(str);
 
    sv = newSVpv(utf8_str, 0);
    SvUTF8_on(sv);
    pfree(utf8_str);
 
    return sv;
}
 
/*
 * croak() with specified message, which is given in the database encoding.
 *
 * Ideally we'd just write croak("%s", str), but plain croak() does not play
 * nice with non-ASCII data.  In modern Perl versions we can call cstr2sv()
 * and pass the result to croak_sv(); in versions that don't have croak_sv(),
 * we have to work harder.
 */
static inline void
croak_cstr(const char *str)
{
    dTHX;
 
#ifdef croak_sv
    /* Use sv_2mortal() to be sure the transient SV gets freed */
    croak_sv(sv_2mortal(cstr2sv(str)));
#else
 
    /*
     * The older way to do this is to assign a UTF8-marked value to ERRSV and
     * then call croak(NULL).  But if we leave it to croak() to append the
     * error location, it does so too late (only after popping the stack) in
     * some Perl versions.  Hence, use mess() to create an SV with the error
     * location info already appended.
     */
    SV         *errsv = get_sv("@", GV_ADD);
    char       *utf8_str = utf_e2u(str);
    SV         *ssv;
 
    ssv = mess("%s", utf8_str);
    SvUTF8_on(ssv);
 
    pfree(utf8_str);
 
    sv_setsv(errsv, ssv);
 
    croak(NULL);
#endif                          /* croak_sv */
}
 
#endif                          /* PL_PERL_H */