postgresql/contrib/seg/segparse.y
John Naylor b086a47a27 Bump minimum version of Bison to 2.3
Since the retirement of some older buildfarm members, the oldest Bison
that gets regular testing is 2.3. MacOS ships that version, and will
continue doing so for the forseeable future because of Apple's policy
regarding GPLv3. While Mac users could use a package manager to install
a newer version, there is no compelling reason to force them do so at
this time.

Reviewed by Andres Freund
Discussion: https://www.postgresql.org/message-id/1097762.1662145681@sss.pgh.pa.us
2022-09-09 12:31:41 +07:00

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%{
/* contrib/seg/segparse.y */
#include "postgres.h"
#include <math.h>
#include "fmgr.h"
#include "utils/builtins.h"
#include "segdata.h"
/*
* 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.
*/
#define YYMALLOC palloc
#define YYFREE pfree
static float seg_atof(const char *value);
static char strbuf[25] = {
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '0',
'0', '0', '0', '0', '\0'
};
%}
/* BISON Declarations */
%parse-param {SEG *result}
%expect 0
%name-prefix="seg_yy"
%union
{
struct BND
{
float val;
char ext;
char sigd;
} bnd;
char *text;
}
%token <text> SEGFLOAT
%token <text> RANGE
%token <text> PLUMIN
%token <text> EXTENSION
%type <bnd> boundary
%type <bnd> deviation
%start range
/* Grammar follows */
%%
range: boundary PLUMIN deviation
{
result->lower = $1.val - $3.val;
result->upper = $1.val + $3.val;
sprintf(strbuf, "%g", result->lower);
result->l_sigd = Max(Min(6, significant_digits(strbuf)), Max($1.sigd, $3.sigd));
sprintf(strbuf, "%g", result->upper);
result->u_sigd = Max(Min(6, significant_digits(strbuf)), Max($1.sigd, $3.sigd));
result->l_ext = '\0';
result->u_ext = '\0';
}
| boundary RANGE boundary
{
result->lower = $1.val;
result->upper = $3.val;
if ( result->lower > result->upper ) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("swapped boundaries: %g is greater than %g",
result->lower, result->upper)));
YYERROR;
}
result->l_sigd = $1.sigd;
result->u_sigd = $3.sigd;
result->l_ext = ( $1.ext ? $1.ext : '\0' );
result->u_ext = ( $3.ext ? $3.ext : '\0' );
}
| boundary RANGE
{
result->lower = $1.val;
result->upper = HUGE_VAL;
result->l_sigd = $1.sigd;
result->u_sigd = 0;
result->l_ext = ( $1.ext ? $1.ext : '\0' );
result->u_ext = '-';
}
| RANGE boundary
{
result->lower = -HUGE_VAL;
result->upper = $2.val;
result->l_sigd = 0;
result->u_sigd = $2.sigd;
result->l_ext = '-';
result->u_ext = ( $2.ext ? $2.ext : '\0' );
}
| boundary
{
result->lower = result->upper = $1.val;
result->l_sigd = result->u_sigd = $1.sigd;
result->l_ext = result->u_ext = ( $1.ext ? $1.ext : '\0' );
}
;
boundary: SEGFLOAT
{
/* temp variable avoids a gcc 3.3.x bug on Sparc64 */
float val = seg_atof($1);
$$.ext = '\0';
$$.sigd = significant_digits($1);
$$.val = val;
}
| EXTENSION SEGFLOAT
{
/* temp variable avoids a gcc 3.3.x bug on Sparc64 */
float val = seg_atof($2);
$$.ext = $1[0];
$$.sigd = significant_digits($2);
$$.val = val;
}
;
deviation: SEGFLOAT
{
/* temp variable avoids a gcc 3.3.x bug on Sparc64 */
float val = seg_atof($1);
$$.ext = '\0';
$$.sigd = significant_digits($1);
$$.val = val;
}
;
%%
static float
seg_atof(const char *value)
{
Datum datum;
datum = DirectFunctionCall1(float4in, CStringGetDatum(value));
return DatumGetFloat4(datum);
}