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sqlite/ext/misc/regexp.c
drh 43afab28a0 GCC 13 has become more quite pedantic about the signature of functions matching the 
type of pointers through which the functions are called.  Make adjustments to
extension functions and test procedures to work around this.  No changes to the
core.

FossilOrigin-Name: ed83b79100b4345235aec990303c4526874f0c2f8701160c4639a80633ebaf70
2025-01-13 11:28:34 +00:00

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/*
** 2012-11-13
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
******************************************************************************
**
** The code in this file implements a compact but reasonably
** efficient regular-expression matcher for posix extended regular
** expressions against UTF8 text.
**
** This file is an SQLite extension. It registers a single function
** named "regexp(A,B)" where A is the regular expression and B is the
** string to be matched. By registering this function, SQLite will also
** then implement the "B regexp A" operator. Note that with the function
** the regular expression comes first, but with the operator it comes
** second.
**
** The following regular expression syntax is supported:
**
** X* zero or more occurrences of X
** X+ one or more occurrences of X
** X? zero or one occurrences of X
** X{p,q} between p and q occurrences of X
** (X) match X
** X|Y X or Y
** ^X X occurring at the beginning of the string
** X$ X occurring at the end of the string
** . Match any single character
** \c Character c where c is one of \{}()[]|*+?.
** \c C-language escapes for c in afnrtv. ex: \t or \n
** \uXXXX Where XXXX is exactly 4 hex digits, unicode value XXXX
** \xXX Where XX is exactly 2 hex digits, unicode value XX
** [abc] Any single character from the set abc
** [^abc] Any single character not in the set abc
** [a-z] Any single character in the range a-z
** [^a-z] Any single character not in the range a-z
** \b Word boundary
** \w Word character. [A-Za-z0-9_]
** \W Non-word character
** \d Digit
** \D Non-digit
** \s Whitespace character
** \S Non-whitespace character
**
** A nondeterministic finite automaton (NFA) is used for matching, so the
** performance is bounded by O(N*M) where N is the size of the regular
** expression and M is the size of the input string. The matcher never
** exhibits exponential behavior. Note that the X{p,q} operator expands
** to p copies of X following by q-p copies of X? and that the size of the
** regular expression in the O(N*M) performance bound is computed after
** this expansion.
*/
#include <string.h>
#include <stdlib.h>
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1
/*
** The following #defines change the names of some functions implemented in
** this file to prevent name collisions with C-library functions of the
** same name.
*/
#define re_match sqlite3re_match
#define re_compile sqlite3re_compile
#define re_free sqlite3re_free
/* The end-of-input character */
#define RE_EOF 0 /* End of input */
#define RE_START 0xfffffff /* Start of input - larger than an UTF-8 */
/* The NFA is implemented as sequence of opcodes taken from the following
** set. Each opcode has a single integer argument.
*/
#define RE_OP_MATCH 1 /* Match the one character in the argument */
#define RE_OP_ANY 2 /* Match any one character. (Implements ".") */
#define RE_OP_ANYSTAR 3 /* Special optimized version of .* */
#define RE_OP_FORK 4 /* Continue to both next and opcode at iArg */
#define RE_OP_GOTO 5 /* Jump to opcode at iArg */
#define RE_OP_ACCEPT 6 /* Halt and indicate a successful match */
#define RE_OP_CC_INC 7 /* Beginning of a [...] character class */
#define RE_OP_CC_EXC 8 /* Beginning of a [^...] character class */
#define RE_OP_CC_VALUE 9 /* Single value in a character class */
#define RE_OP_CC_RANGE 10 /* Range of values in a character class */
#define RE_OP_WORD 11 /* Perl word character [A-Za-z0-9_] */
#define RE_OP_NOTWORD 12 /* Not a perl word character */
#define RE_OP_DIGIT 13 /* digit: [0-9] */
#define RE_OP_NOTDIGIT 14 /* Not a digit */
#define RE_OP_SPACE 15 /* space: [ \t\n\r\v\f] */
#define RE_OP_NOTSPACE 16 /* Not a digit */
#define RE_OP_BOUNDARY 17 /* Boundary between word and non-word */
#define RE_OP_ATSTART 18 /* Currently at the start of the string */
#if defined(SQLITE_DEBUG)
/* Opcode names used for symbolic debugging */
static const char *ReOpName[] = {
"EOF",
"MATCH",
"ANY",
"ANYSTAR",
"FORK",
"GOTO",
"ACCEPT",
"CC_INC",
"CC_EXC",
"CC_VALUE",
"CC_RANGE",
"WORD",
"NOTWORD",
"DIGIT",
"NOTDIGIT",
"SPACE",
"NOTSPACE",
"BOUNDARY",
"ATSTART",
};
#endif /* SQLITE_DEBUG */
/* Each opcode is a "state" in the NFA */
typedef unsigned short ReStateNumber;
/* Because this is an NFA and not a DFA, multiple states can be active at
** once. An instance of the following object records all active states in
** the NFA. The implementation is optimized for the common case where the
** number of actives states is small.
*/
typedef struct ReStateSet {
unsigned nState; /* Number of current states */
ReStateNumber *aState; /* Current states */
} ReStateSet;
/* An input string read one character at a time.
*/
typedef struct ReInput ReInput;
struct ReInput {
const unsigned char *z; /* All text */
int i; /* Next byte to read */
int mx; /* EOF when i>=mx */
};
/* A compiled NFA (or an NFA that is in the process of being compiled) is
** an instance of the following object.
*/
typedef struct ReCompiled ReCompiled;
struct ReCompiled {
ReInput sIn; /* Regular expression text */
const char *zErr; /* Error message to return */
char *aOp; /* Operators for the virtual machine */
int *aArg; /* Arguments to each operator */
unsigned (*xNextChar)(ReInput*); /* Next character function */
unsigned char zInit[12]; /* Initial text to match */
int nInit; /* Number of bytes in zInit */
unsigned nState; /* Number of entries in aOp[] and aArg[] */
unsigned nAlloc; /* Slots allocated for aOp[] and aArg[] */
};
/* Add a state to the given state set if it is not already there */
static void re_add_state(ReStateSet *pSet, int newState){
unsigned i;
for(i=0; i<pSet->nState; i++) if( pSet->aState[i]==newState ) return;
pSet->aState[pSet->nState++] = (ReStateNumber)newState;
}
/* Extract the next unicode character from *pzIn and return it. Advance
** *pzIn to the first byte past the end of the character returned. To
** be clear: this routine converts utf8 to unicode. This routine is
** optimized for the common case where the next character is a single byte.
*/
static unsigned re_next_char(ReInput *p){
unsigned c;
if( p->i>=p->mx ) return 0;
c = p->z[p->i++];
if( c>=0x80 ){
if( (c&0xe0)==0xc0 && p->i<p->mx && (p->z[p->i]&0xc0)==0x80 ){
c = (c&0x1f)<<6 | (p->z[p->i++]&0x3f);
if( c<0x80 ) c = 0xfffd;
}else if( (c&0xf0)==0xe0 && p->i+1<p->mx && (p->z[p->i]&0xc0)==0x80
&& (p->z[p->i+1]&0xc0)==0x80 ){
c = (c&0x0f)<<12 | ((p->z[p->i]&0x3f)<<6) | (p->z[p->i+1]&0x3f);
p->i += 2;
if( c<=0x7ff || (c>=0xd800 && c<=0xdfff) ) c = 0xfffd;
}else if( (c&0xf8)==0xf0 && p->i+2<p->mx && (p->z[p->i]&0xc0)==0x80
&& (p->z[p->i+1]&0xc0)==0x80 && (p->z[p->i+2]&0xc0)==0x80 ){
c = (c&0x07)<<18 | ((p->z[p->i]&0x3f)<<12) | ((p->z[p->i+1]&0x3f)<<6)
| (p->z[p->i+2]&0x3f);
p->i += 3;
if( c<=0xffff || c>0x10ffff ) c = 0xfffd;
}else{
c = 0xfffd;
}
}
return c;
}
static unsigned re_next_char_nocase(ReInput *p){
unsigned c = re_next_char(p);
if( c>='A' && c<='Z' ) c += 'a' - 'A';
return c;
}
/* Return true if c is a perl "word" character: [A-Za-z0-9_] */
static int re_word_char(int c){
return (c>='0' && c<='9') || (c>='a' && c<='z')
|| (c>='A' && c<='Z') || c=='_';
}
/* Return true if c is a "digit" character: [0-9] */
static int re_digit_char(int c){
return (c>='0' && c<='9');
}
/* Return true if c is a perl "space" character: [ \t\r\n\v\f] */
static int re_space_char(int c){
return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
}
/* Run a compiled regular expression on the zero-terminated input
** string zIn[]. Return true on a match and false if there is no match.
*/
static int re_match(ReCompiled *pRe, const unsigned char *zIn, int nIn){
ReStateSet aStateSet[2], *pThis, *pNext;
ReStateNumber aSpace[100];
ReStateNumber *pToFree;
unsigned int i = 0;
unsigned int iSwap = 0;
int c = RE_START;
int cPrev = 0;
int rc = 0;
ReInput in;
in.z = zIn;
in.i = 0;
in.mx = nIn>=0 ? nIn : (int)strlen((char const*)zIn);
/* Look for the initial prefix match, if there is one. */
if( pRe->nInit ){
unsigned char x = pRe->zInit[0];
while( in.i+pRe->nInit<=in.mx
&& (zIn[in.i]!=x ||
strncmp((const char*)zIn+in.i, (const char*)pRe->zInit, pRe->nInit)!=0)
){
in.i++;
}
if( in.i+pRe->nInit>in.mx ) return 0;
c = RE_START-1;
}
if( pRe->nState<=(sizeof(aSpace)/(sizeof(aSpace[0])*2)) ){
pToFree = 0;
aStateSet[0].aState = aSpace;
}else{
pToFree = sqlite3_malloc64( sizeof(ReStateNumber)*2*pRe->nState );
if( pToFree==0 ) return -1;
aStateSet[0].aState = pToFree;
}
aStateSet[1].aState = &aStateSet[0].aState[pRe->nState];
pNext = &aStateSet[1];
pNext->nState = 0;
re_add_state(pNext, 0);
while( c!=RE_EOF && pNext->nState>0 ){
cPrev = c;
c = pRe->xNextChar(&in);
pThis = pNext;
pNext = &aStateSet[iSwap];
iSwap = 1 - iSwap;
pNext->nState = 0;
for(i=0; i<pThis->nState; i++){
int x = pThis->aState[i];
switch( pRe->aOp[x] ){
case RE_OP_MATCH: {
if( pRe->aArg[x]==c ) re_add_state(pNext, x+1);
break;
}
case RE_OP_ATSTART: {
if( cPrev==RE_START ) re_add_state(pThis, x+1);
break;
}
case RE_OP_ANY: {
if( c!=0 ) re_add_state(pNext, x+1);
break;
}
case RE_OP_WORD: {
if( re_word_char(c) ) re_add_state(pNext, x+1);
break;
}
case RE_OP_NOTWORD: {
if( !re_word_char(c) && c!=0 ) re_add_state(pNext, x+1);
break;
}
case RE_OP_DIGIT: {
if( re_digit_char(c) ) re_add_state(pNext, x+1);
break;
}
case RE_OP_NOTDIGIT: {
if( !re_digit_char(c) && c!=0 ) re_add_state(pNext, x+1);
break;
}
case RE_OP_SPACE: {
if( re_space_char(c) ) re_add_state(pNext, x+1);
break;
}
case RE_OP_NOTSPACE: {
if( !re_space_char(c) && c!=0 ) re_add_state(pNext, x+1);
break;
}
case RE_OP_BOUNDARY: {
if( re_word_char(c)!=re_word_char(cPrev) ) re_add_state(pThis, x+1);
break;
}
case RE_OP_ANYSTAR: {
re_add_state(pNext, x);
re_add_state(pThis, x+1);
break;
}
case RE_OP_FORK: {
re_add_state(pThis, x+pRe->aArg[x]);
re_add_state(pThis, x+1);
break;
}
case RE_OP_GOTO: {
re_add_state(pThis, x+pRe->aArg[x]);
break;
}
case RE_OP_ACCEPT: {
rc = 1;
goto re_match_end;
}
case RE_OP_CC_EXC: {
if( c==0 ) break;
/* fall-through */ goto re_op_cc_inc;
}
case RE_OP_CC_INC: re_op_cc_inc: {
int j = 1;
int n = pRe->aArg[x];
int hit = 0;
for(j=1; j>0 && j<n; j++){
if( pRe->aOp[x+j]==RE_OP_CC_VALUE ){
if( pRe->aArg[x+j]==c ){
hit = 1;
j = -1;
}
}else{
if( pRe->aArg[x+j]<=c && pRe->aArg[x+j+1]>=c ){
hit = 1;
j = -1;
}else{
j++;
}
}
}
if( pRe->aOp[x]==RE_OP_CC_EXC ) hit = !hit;
if( hit ) re_add_state(pNext, x+n);
break;
}
}
}
}
for(i=0; i<pNext->nState; i++){
int x = pNext->aState[i];
while( pRe->aOp[x]==RE_OP_GOTO ) x += pRe->aArg[x];
if( pRe->aOp[x]==RE_OP_ACCEPT ){ rc = 1; break; }
}
re_match_end:
sqlite3_free(pToFree);
return rc;
}
/* Resize the opcode and argument arrays for an RE under construction.
*/
static int re_resize(ReCompiled *p, int N){
char *aOp;
int *aArg;
aOp = sqlite3_realloc64(p->aOp, N*sizeof(p->aOp[0]));
if( aOp==0 ) return 1;
p->aOp = aOp;
aArg = sqlite3_realloc64(p->aArg, N*sizeof(p->aArg[0]));
if( aArg==0 ) return 1;
p->aArg = aArg;
p->nAlloc = N;
return 0;
}
/* 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;
}
/* Append a new opcode and argument to the end of the RE under construction.
*/
static int re_append(ReCompiled *p, int op, int arg){
return re_insert(p, p->nState, op, arg);
}
/* 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;
}
/* Return true if c is a hexadecimal digit character: [0-9a-fA-F]
** If c is a hex digit, also set *pV = (*pV)*16 + valueof(c). If
** c is not a hex digit *pV is unchanged.
*/
static int re_hex(int c, int *pV){
if( c>='0' && c<='9' ){
c -= '0';
}else if( c>='a' && c<='f' ){
c -= 'a' - 10;
}else if( c>='A' && c<='F' ){
c -= 'A' - 10;
}else{
return 0;
}
*pV = (*pV)*16 + (c & 0xff);
return 1;
}
/* A backslash character has been seen, read the next character and
** return its interpretation.
*/
static unsigned re_esc_char(ReCompiled *p){
static const char zEsc[] = "afnrtv\\()*.+?[$^{|}]";
static const char zTrans[] = "\a\f\n\r\t\v";
int i, v = 0;
char c;
if( p->sIn.i>=p->sIn.mx ) return 0;
c = p->sIn.z[p->sIn.i];
if( c=='u' && p->sIn.i+4<p->sIn.mx ){
const unsigned char *zIn = p->sIn.z + p->sIn.i;
if( re_hex(zIn[1],&v)
&& re_hex(zIn[2],&v)
&& re_hex(zIn[3],&v)
&& re_hex(zIn[4],&v)
){
p->sIn.i += 5;
return v;
}
}
if( c=='x' && p->sIn.i+2<p->sIn.mx ){
const unsigned char *zIn = p->sIn.z + p->sIn.i;
if( re_hex(zIn[1],&v)
&& re_hex(zIn[2],&v)
){
p->sIn.i += 3;
return v;
}
}
for(i=0; zEsc[i] && zEsc[i]!=c; i++){}
if( zEsc[i] ){
if( i<6 ) c = zTrans[i];
p->sIn.i++;
}else{
p->zErr = "unknown \\ escape";
}
return c;
}
/* Forward declaration */
static const char *re_subcompile_string(ReCompiled*);
/* Peek at the next byte of input */
static unsigned char rePeek(ReCompiled *p){
return p->sIn.i<p->sIn.mx ? p->sIn.z[p->sIn.i] : 0;
}
/* Compile RE text into a sequence of opcodes. Continue up to the
** first unmatched ")" character, then return. If an error is found,
** return a pointer to the error message string.
*/
static const char *re_subcompile_re(ReCompiled *p){
const char *zErr;
int iStart, iEnd, iGoto;
iStart = p->nState;
zErr = re_subcompile_string(p);
if( zErr ) return zErr;
while( rePeek(p)=='|' ){
iEnd = p->nState;
re_insert(p, iStart, RE_OP_FORK, iEnd + 2 - iStart);
iGoto = re_append(p, RE_OP_GOTO, 0);
p->sIn.i++;
zErr = re_subcompile_string(p);
if( zErr ) return zErr;
p->aArg[iGoto] = p->nState - iGoto;
}
return 0;
}
/* Compile an element of regular expression text (anything that can be
** an operand to the "|" operator). Return NULL on success or a pointer
** to the error message if there is a problem.
*/
static const char *re_subcompile_string(ReCompiled *p){
int iPrev = -1;
int iStart;
unsigned c;
const char *zErr;
while( (c = p->xNextChar(&p->sIn))!=0 ){
iStart = p->nState;
switch( c ){
case '|':
case ')': {
p->sIn.i--;
return 0;
}
case '(': {
zErr = re_subcompile_re(p);
if( zErr ) return zErr;
if( rePeek(p)!=')' ) return "unmatched '('";
p->sIn.i++;
break;
}
case '.': {
if( rePeek(p)=='*' ){
re_append(p, RE_OP_ANYSTAR, 0);
p->sIn.i++;
}else{
re_append(p, RE_OP_ANY, 0);
}
break;
}
case '*': {
if( iPrev<0 ) return "'*' without operand";
re_insert(p, iPrev, RE_OP_GOTO, p->nState - iPrev + 1);
re_append(p, RE_OP_FORK, iPrev - p->nState + 1);
break;
}
case '+': {
if( iPrev<0 ) return "'+' without operand";
re_append(p, RE_OP_FORK, iPrev - p->nState);
break;
}
case '?': {
if( iPrev<0 ) return "'?' without operand";
re_insert(p, iPrev, RE_OP_FORK, p->nState - iPrev+1);
break;
}
case '$': {
re_append(p, RE_OP_MATCH, RE_EOF);
break;
}
case '^': {
re_append(p, RE_OP_ATSTART, 0);
break;
}
case '{': {
int m = 0, n = 0;
int sz, j;
if( iPrev<0 ) return "'{m,n}' without operand";
while( (c=rePeek(p))>='0' && c<='9' ){ m = m*10 + c - '0'; p->sIn.i++; }
n = m;
if( c==',' ){
p->sIn.i++;
n = 0;
while( (c=rePeek(p))>='0' && c<='9' ){ n = n*10 + c-'0'; p->sIn.i++; }
}
if( c!='}' ) return "unmatched '{'";
if( n>0 && n<m ) return "n less than m in '{m,n}'";
p->sIn.i++;
sz = p->nState - iPrev;
if( m==0 ){
if( n==0 ) return "both m and n are zero in '{m,n}'";
re_insert(p, iPrev, RE_OP_FORK, sz+1);
iPrev++;
n--;
}else{
for(j=1; j<m; j++) re_copy(p, iPrev, sz);
}
for(j=m; j<n; j++){
re_append(p, RE_OP_FORK, sz+1);
re_copy(p, iPrev, sz);
}
if( n==0 && m>0 ){
re_append(p, RE_OP_FORK, -sz);
}
break;
}
case '[': {
unsigned int iFirst = p->nState;
if( rePeek(p)=='^' ){
re_append(p, RE_OP_CC_EXC, 0);
p->sIn.i++;
}else{
re_append(p, RE_OP_CC_INC, 0);
}
while( (c = p->xNextChar(&p->sIn))!=0 ){
if( c=='[' && rePeek(p)==':' ){
return "POSIX character classes not supported";
}
if( c=='\\' ) c = re_esc_char(p);
if( rePeek(p)=='-' ){
re_append(p, RE_OP_CC_RANGE, c);
p->sIn.i++;
c = p->xNextChar(&p->sIn);
if( c=='\\' ) c = re_esc_char(p);
re_append(p, RE_OP_CC_RANGE, c);
}else{
re_append(p, RE_OP_CC_VALUE, c);
}
if( rePeek(p)==']' ){ p->sIn.i++; break; }
}
if( c==0 ) return "unclosed '['";
if( p->nState>iFirst ) p->aArg[iFirst] = p->nState - iFirst;
break;
}
case '\\': {
int specialOp = 0;
switch( rePeek(p) ){
case 'b': specialOp = RE_OP_BOUNDARY; break;
case 'd': specialOp = RE_OP_DIGIT; break;
case 'D': specialOp = RE_OP_NOTDIGIT; break;
case 's': specialOp = RE_OP_SPACE; break;
case 'S': specialOp = RE_OP_NOTSPACE; break;
case 'w': specialOp = RE_OP_WORD; break;
case 'W': specialOp = RE_OP_NOTWORD; break;
}
if( specialOp ){
p->sIn.i++;
re_append(p, specialOp, 0);
}else{
c = re_esc_char(p);
re_append(p, RE_OP_MATCH, c);
}
break;
}
default: {
re_append(p, RE_OP_MATCH, c);
break;
}
}
iPrev = iStart;
}
return 0;
}
/* Free and reclaim all the memory used by a previously compiled
** regular expression. Applications should invoke this routine once
** for every call to re_compile() to avoid memory leaks.
*/
static void re_free(void *p){
ReCompiled *pRe = (ReCompiled*)p;
if( pRe ){
sqlite3_free(pRe->aOp);
sqlite3_free(pRe->aArg);
sqlite3_free(pRe);
}
}
/*
** 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.
*/
static 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( 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 about 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 && !noCase ){
for(j=0, i=1; j<(int)sizeof(pRe->zInit)-2 && pRe->aOp[i]==RE_OP_MATCH; i++){
unsigned x = pRe->aArg[i];
if( x<=0x7f ){
pRe->zInit[j++] = (unsigned char)x;
}else if( x<=0x7ff ){
pRe->zInit[j++] = (unsigned char)(0xc0 | (x>>6));
pRe->zInit[j++] = 0x80 | (x&0x3f);
}else if( x<=0xffff ){
pRe->zInit[j++] = (unsigned char)(0xe0 | (x>>12));
pRe->zInit[j++] = 0x80 | ((x>>6)&0x3f);
pRe->zInit[j++] = 0x80 | (x&0x3f);
}else{
break;
}
}
if( j>0 && pRe->zInit[j-1]==0 ) j--;
pRe->nInit = j;
}
return pRe->zErr;
}
/*
** Implementation of the regexp() SQL function. This function implements
** the build-in REGEXP operator. The first argument to the function is the
** pattern and the second argument is the string. So, the SQL statements:
**
** A REGEXP B
**
** is implemented as regexp(B,A).
*/
static void re_sql_func(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
ReCompiled *pRe; /* Compiled regular expression */
const char *zPattern; /* The regular expression */
const unsigned char *zStr;/* String being searched */
const char *zErr; /* Compile error message */
int setAux = 0; /* True to invoke sqlite3_set_auxdata() */
(void)argc; /* Unused */
pRe = sqlite3_get_auxdata(context, 0);
if( pRe==0 ){
zPattern = (const char*)sqlite3_value_text(argv[0]);
if( zPattern==0 ) return;
zErr = re_compile(&pRe, zPattern, sqlite3_user_data(context)!=0);
if( zErr ){
re_free(pRe);
sqlite3_result_error(context, zErr, -1);
return;
}
if( pRe==0 ){
sqlite3_result_error_nomem(context);
return;
}
setAux = 1;
}
zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
if( zStr!=0 ){
sqlite3_result_int(context, re_match(pRe, zStr, -1));
}
if( setAux ){
sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
}
}
#if defined(SQLITE_DEBUG)
/*
** This function is used for testing and debugging only. It is only available
** if the SQLITE_DEBUG compile-time option is used.
**
** Compile a regular expression and then convert the compiled expression into
** text and return that text.
*/
static void re_bytecode_func(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const char *zPattern;
const char *zErr;
ReCompiled *pRe;
sqlite3_str *pStr;
int i;
int n;
char *z;
(void)argc;
zPattern = (const char*)sqlite3_value_text(argv[0]);
if( zPattern==0 ) return;
zErr = re_compile(&pRe, zPattern, sqlite3_user_data(context)!=0);
if( zErr ){
re_free(pRe);
sqlite3_result_error(context, zErr, -1);
return;
}
if( pRe==0 ){
sqlite3_result_error_nomem(context);
return;
}
pStr = sqlite3_str_new(0);
if( pStr==0 ) goto re_bytecode_func_err;
if( pRe->nInit>0 ){
sqlite3_str_appendf(pStr, "INIT ");
for(i=0; i<pRe->nInit; i++){
sqlite3_str_appendf(pStr, "%02x", pRe->zInit[i]);
}
sqlite3_str_appendf(pStr, "\n");
}
for(i=0; (unsigned)i<pRe->nState; i++){
sqlite3_str_appendf(pStr, "%-8s %4d\n",
ReOpName[(unsigned char)pRe->aOp[i]], pRe->aArg[i]);
}
n = sqlite3_str_length(pStr);
z = sqlite3_str_finish(pStr);
if( n==0 ){
sqlite3_free(z);
}else{
sqlite3_result_text(context, z, n-1, sqlite3_free);
}
re_bytecode_func_err:
re_free(pRe);
}
#endif /* SQLITE_DEBUG */
/*
** Invoke this routine to register the regexp() function with the
** SQLite database connection.
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_regexp_init(
sqlite3 *db,
char **pzErrMsg,
const sqlite3_api_routines *pApi
){
int rc = SQLITE_OK;
SQLITE_EXTENSION_INIT2(pApi);
(void)pzErrMsg; /* Unused */
rc = sqlite3_create_function(db, "regexp", 2,
SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
0, re_sql_func, 0, 0);
if( rc==SQLITE_OK ){
/* The regexpi(PATTERN,STRING) function is a case-insensitive version
** of regexp(PATTERN,STRING). */
rc = sqlite3_create_function(db, "regexpi", 2,
SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
(void*)db, re_sql_func, 0, 0);
#if defined(SQLITE_DEBUG)
if( rc==SQLITE_OK ){
rc = sqlite3_create_function(db, "regexp_bytecode", 1,
SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
0, re_bytecode_func, 0, 0);
}
#endif /* SQLITE_DEBUG */
}
return rc;
}
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