/*
**??mod_define.c?-?Apache?module?for?configuration?defines?（$xxx）
**
**??Copyright?（c）?1998-2000?Ralf?S.?Engelschall?
**??Copyright?（c）?1998-2000?Christian?Reiber?
**
**??Permission?to?use?copy?modify?and?distribute?this?software?for
**??any?purpose?with?or?without?fee?is?hereby?granted?provided?that
**??the?above?copyright?notice?and?this?permission?notice?appear?in?all
**??copies.
**
**??THIS?SOFTWARE?IS?PROVIDED?‘‘AS?IS‘‘?AND?ANY?EXPRESSED?OR?IMPLIED
**??WARRANTIES?INCLUDING?BUT?NOT?LIMITED?TO?THE?IMPLIED?WARRANTIES?OF
**??MERCHANTABILITY?AND?FITNESS?FOR?A?PARTICULAR?PURPOSE?ARE?DISCLAIMED.
**??IN?NO?EVENT?SHALL?THE?AUTHORS?AND?COPYRIGHT?HOLDERS?AND?THEIR
**??CONTRIBUTORS?BE?LIABLE?FOR?ANY?DIRECT?INDIRECT?INCIDENTAL
**??SPECIAL?EXEMPLARY?OR?CONSEQUENTIAL?DAMAGES?（INCLUDING?BUT?NOT
**??LIMITED?TO?PROCUREMENT?OF?SUBSTITUTE?GOODS?OR?SERVICES;?LOSS?OF
**??USE?DATA?OR?PROFITS;?OR?BUSINESS?INTERRUPTION）?HOWEVER?CAUSED?AND
**??ON?ANY?THEORY?OF?LIABILITY?WHETHER?IN?CONTRACT?STRICT?LIABILITY
**??OR?TORT?（INCLUDING?NEGLIGENCE?OR?OTHERWISE）?ARISING?IN?ANY?WAY?OUT
**??OF?THE?USE?OF?THIS?SOFTWARE?EVEN?IF?ADVISED?OF?THE?POSSIBILITY?OF
**??SUCH?DAMAGE.
*/

/*
?*??HISTORY
?*
?*??v1.0:?Originally?written?in?December?1998?by
?*????????Ralf?S.?Engelschall??and
?*????????Christian?Reiber?
?*
?*??v1.1:?Completely?Overhauled?in?August?1999?by
?*????????Ralf?S.?Engelschall?
?*/

#include?“ap_config.h“
#include?“ap_ctype.h“
#include?“httpd.h“
#include?“http_config.h“
#include?“http_conf_globals.h“
#include?“http_core.h“
#include?“http_log.h“

#ifndef?EAPI
#error?“This?module?requires?the?Extended?API?（EAPI）?facilities.“
#endif

/*
?*?The?global?table?of?defines
?*/

static?table?*tDefines?????????=?NULL;???/*?global?table?of?defines?*/
static?int????bOnceSeenADefine?=?FALSE;??/*?optimization?flag?*/

/*
?*?Forward?declaration
?*/
static?int???DefineIndex??????（pool?*?char?*?int?*?int?*?char?**）;
static?char?*DefineFetch??????（pool?*?char?*）;
static?char?*DefineExpand?????（pool?*?char?*?int?char?*）;
static?void??DefineInit???????（pool?*）;
static?void??DefineCleanup????（void?*）;
static?char?*DefineRewriteHook（cmd_parms?*?void?*?const?char?*）;

/*
?*?Character?classes?for?scanner?function
?*/
typedef?enum?{
????CC_ESCAPE?CC_DOLLAR?CC_BRACEOPEN?CC_BRACECLOSE
????CC_IDCHAR1?CC_IDCHAR?CC_OTHER?CC_EOS
}?CharClass;

/*
?*?Scanner?states?for?scanner?function
?*/
typedef?enum?{
????SS_NONE?SS_SKIP?SS_DOLLAR?SS_TOKEN_BRACED
????SS_TOKEN_UNBRACED?SS_ERROR?SS_FOUND
}?ScanState;

/*
?*?Default?meta?characters
?*/
#define?DEFAULT_MC_ESCAPE??????“\\“
#define?DEFAULT_MC_DOLLAR??????“$“
#define?DEFAULT_MC_BRACEOPEN???“{“
#define?DEFAULT_MC_BRACECLOSE??“}“

/*
?*?Scanner?for?variable?constructs?$xxx?and?${xxx}
?*/
static?int?DefineIndex（pool?*p?char?*cpLine?int?*pos?int?*len?char?**cpVar）
{
????int?rc;
????char?*cp;
????char?*cp2;
????CharCl