/* Make a copy of N opcodes starting at iStart onto the end of the RE
** under construction.
*/
static void re_copy(ReCompiled *p, int iStart, int N)
{
if (p->nState + N >= p->nAlloc && re_resize(p, p->nAlloc * 2 + N)) return;
memcpy(&p->aOp[p->nState], &p->aOp[iStart], N * sizeof(p->aOp[0]));
memcpy(&p->aArg[p->nState], &p->aArg[iStart], N * sizeof(p->aArg[0]));
p->nState += N;
}
/* Insert a new opcode and argument into an RE under construction. The
** insertion point is just prior to existing opcode iBefore.
*/
static int re_insert(ReCompiled *p, int iBefore, int op, int arg){
int i;
if( p->nAlloc<=p->nState && re_resize(p, p->nAlloc*2) ) return 0;
for(i=p->nState; i>iBefore; i--){
p->aOp[i] = p->aOp[i-1];
p->aArg[i] = p->aArg[i-1];
}
p->nState++;
p->aOp[iBefore] = (char)op;
p->aArg[iBefore] = arg;
return iBefore;
}
/*
** Compile a textual regular expression in zIn[] into a compiled regular
** expression suitable for us by re_match() and return a pointer to the
** compiled regular expression in *ppRe. Return NULL on success or an
** error message if something goes wrong.
*/
const char *re_compile(ReCompiled **ppRe, const char *zIn, int noCase){
ReCompiled *pRe;
const char *zErr;
int i, j;
*ppRe = 0;
pRe = sqlite3_malloc( sizeof(*pRe) );
if( pRe==0 ){
return "out of memory";
}
memset(pRe, 0, sizeof(*pRe));
pRe->xNextChar = noCase ? re_next_char_nocase : re_next_char;
if( re_resize(pRe, 30) ){
re_free(pRe);
return "out of memory";
}
if( zIn[0]=='^' ){
zIn++;
}else{
re_append(pRe, RE_OP_ANYSTAR, 0);
}
pRe->sIn.z = (unsigned char*)zIn;
pRe->sIn.i = 0;
pRe->sIn.mx = (int)strlen(zIn);
zErr = re_subcompile_re(pRe);
if( zErr ){
re_free(pRe);
return zErr;
}
if( rePeek(pRe)=='$' && pRe->sIn.i+1>=pRe->sIn.mx ){
re_append(pRe, RE_OP_MATCH, RE_EOF);
re_append(pRe, RE_OP_ACCEPT, 0);
*ppRe = pRe;
}else if( pRe->sIn.i>=pRe->sIn.mx ){
re_append(pRe, RE_OP_ACCEPT, 0);
*ppRe = pRe;
}else{
re_free(pRe);
return "unrecognized character";
}
/* The following is a performance optimization. If the regex begins with
** ".*" (if the input regex lacks an initial "^") and afterwards there are
** one or more matching characters, enter those matching characters into
** zInit[]. The re_match() routine can then search ahead in the input
** string looking for the initial match without having to run the whole
** regex engine over the string. Do not worry able trying to match
** unicode characters beyond plane 0 - those are very rare and this is
** just an optimization. */
if( pRe->aOp[0]==RE_OP_ANYSTAR ){
for(j=0, i=1; j<sizeof(pRe->zInit)-2 && pRe->aOp[i]==RE_OP_MATCH; i++){
unsigned x = pRe->aArg[i];
if( x<=127 ){
pRe->zInit[j++] = (unsigned char)x;
}else if( x<=0xfff ){
pRe->zInit[j++] = (unsigned char)(0xc0 | (x>>6));
pRe->zInit[j++] = 0x80 | (x&0x3f);
}else if( x<=0xffff ){
pRe->zInit[j++] = (unsigned char)(0xd0 | (x>>12));
pRe->zInit[j++] = 0x80 | ((x>>6)&0x3f);
pRe->zInit[j++] = 0x80 | (x&0x3f);
}else{
