From 4f49b16079b27d7ce633619e4cddfdf2bffbc952 Mon Sep 17 00:00:00 2001 From: cashmere Date: Fri, 4 Sep 2026 09:05:24 +0200 Subject: initial commit --- src/regexp.c | 1171 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1171 insertions(+) create mode 100644 src/regexp.c (limited to 'src/regexp.c') diff --git a/src/regexp.c b/src/regexp.c new file mode 100644 index 0000000..4a6005b --- /dev/null +++ b/src/regexp.c @@ -0,0 +1,1171 @@ +/* +** Copyright (c) 2013 D. Richard Hipp +** +** This program is free software; you can redistribute it and/or +** modify it under the terms of the Simplified BSD License (also +** known as the "2-Clause License" or "FreeBSD License".) +** +** This program is distributed in the hope that it will be useful, +** but without any warranty; without even the implied warranty of +** merchantability or fitness for a particular purpose. +** +** Author contact information: +** drh@hwaci.com +** http://www.hwaci.com/drh/ +** +****************************************************************************** +** +** This file was adapted from the ext/misc/regexp.c file in SQLite3. That +** file is in the public domain. +** +** See ../www/grep.md for details of the algorithm and RE dialect. +** +** +** 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. +** +** To help prevent DoS attacks, the maximum size of the NFA is restricted. +*/ +#include "config.h" +#include "regexp.h" + +/* 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 */ + +/* 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; + +#if INTERFACE +/* An input string read one character at a time. +*/ +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. +*/ +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[] */ + unsigned mxAlloc; /* Complexity limit */ +}; +#endif + +/* 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; inState; 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->imx && (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+1mx && (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+2mx && (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); + return unicode_fold(c,2); +} + +/* Return true if c is a perl "word" character: [A-Za-z0-9_] */ +static int re_word_char(int c){ + return unicode_isalnum(c) || 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. +*/ +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 = fossil_malloc( 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; inState; 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 && jaOp[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; inState; 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: + fossil_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; + if( N>p->mxAlloc ){ p->zErr = "REGEXP pattern too big"; return 1; } + aOp = fossil_realloc(p->aOp, N*sizeof(p->aOp[0])); + if( aOp==0 ){ p->zErr = "out of memory"; return 1; } + p->aOp = aOp; + aArg = fossil_realloc(p->aArg, N*sizeof(p->aArg[0])); + if( aArg==0 ){ p->zErr = "out of memory"; 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+4sIn.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+2sIn.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.isIn.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 '{': { + unsigned int m = 0, n = 0; + unsigned int sz, j; + if( iPrev<0 ) return "'{m,n}' without operand"; + while( (c=rePeek(p))>='0' && c<='9' ){ + m = m*10 + c - '0'; + if( m*2>p->mxAlloc ) return "REGEXP pattern too big"; + p->sIn.i++; + } + n = m; + if( c==',' ){ + p->sIn.i++; + n = 0; + while( (c=rePeek(p))>='0' && c<='9' ){ + n = n*10 + c-'0'; + if( n*2>p->mxAlloc ) return "REGEXP pattern too big"; + p->sIn.i++; + } + } + if( c!='}' ) return "unmatched '{'"; + if( nsIn.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; j0 ){ + re_append(p, RE_OP_FORK, -(int)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. +*/ +void re_free(ReCompiled *pRe){ + if( pRe ){ + fossil_free(pRe->aOp); + fossil_free(pRe->aArg); + fossil_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, /* OUT: write compiled NFA here */ + const char *zIn, /* Input regular expression */ + int mxRe, /* Complexity limit */ + int noCase /* True for caseless comparisons */ +){ + ReCompiled *pRe; + const char *zErr; + int i, j; + + *ppRe = 0; + pRe = fossil_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; + pRe->mxAlloc = mxRe; + if( re_resize(pRe, 30) ){ + zErr = pRe->zErr; + re_free(pRe); + return zErr; + } + 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 = fossil_re_compile(&pRe, zPattern, sqlite3_user_data(context)!=0); + if( zErr ){ + re_free(pRe); + /* The original SQLite function from which this code was copied raises + ** an error if the REGEXP contained a syntax error. This variant + ** silently fails to match, as that works better for Fossil. + ** sqlite3_result_error(context, zErr, -1); */ + sqlite3_result_int(context, 0); + 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); + } +} + +/* +** Invoke this routine to register the regexp() function with the +** SQLite database connection. +*/ +int re_add_sql_func(sqlite3 *db){ + int rc; + 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); + } + return rc; +} + +/* +** The input zIn is a string that we want to match exactly as part of +** a regular expression. Return a new string (in space obtained from +** fossil_malloc() or the equivalent) that escapes all regexp syntax +** characters in zIn. +*/ +char *re_quote(const char *zIn){ + Blob out; + blob_init(&out, 0, 0); + while( zIn[0] ){ + switch( zIn[0] ){ + case '.': + case '?': + case '*': + case '+': + case '\\': + case '(': + case ')': + case '[': + case ']': + case '|': + case '^': + case '$': + case '{': + case '}': { + blob_appendf(&out,"\\x%02x", (unsigned char)zIn[0]); + break; + } + default: { + blob_append_char(&out, zIn[0]); + break; + } + } + zIn++; + } + blob_materialize(&out); + return out.aData; +} + +/* +** SETTING: regexp-limit width=8 default=1000 +** +** Limit the size of the bytecode used to implement a regular expression +** to this many steps. It is important to limit this to avoid possible +** DoS attacks. +*/ + +/* +** Compile an RE using re_maxlen(). +*/ +const char *fossil_re_compile( + ReCompiled **ppRe, /* OUT: write compiled NFA here */ + const char *zIn, /* Input regular expression */ + int noCase /* True for caseless comparisons */ +){ + int mxLen = g.db ? db_get_int("regexp-limit",1000) : 1000; + return re_compile(ppRe, zIn, mxLen, noCase); +} + +/* +** Run a "grep" over a single file read from disk. +*/ +static void grep_file(ReCompiled *pRe, const char *zFile, FILE *in){ + int ln = 0; + int n; + char zLine[2000]; + while( fgets(zLine, sizeof(zLine), in) ){ + ln++; + n = (int)strlen(zLine); + while( n && (zLine[n-1]=='\n' || zLine[n-1]=='\r') ) n--; + if( re_match(pRe, (const unsigned char*)zLine, n) ){ + fossil_print("%s:%d:%.*s\n", zFile, ln, n, zLine); + } + } +} + +/* +** Flags for grep_buffer() +*/ +#define GREP_EXISTS 0x001 /* If any match, print only the name and stop */ +#define GREP_QUIET 0x002 /* Return code only */ + +/* +** Run a "grep" over a text file +*/ +static int grep_buffer( + ReCompiled *pRe, + const char *zName, + const char *z, + u32 flags +){ + int i, j, n, ln, cnt; + for(i=j=ln=cnt=0; z[i]; i=j+1){ + for(j=i; z[j] && z[j]!='\n'; j++){} + n = j - i; + ln++; + if( re_match(pRe, (const unsigned char*)(z+i), j-i) ){ + cnt++; + if( flags & GREP_EXISTS ){ + if( (flags & GREP_QUIET)==0 && zName ) fossil_print("%s\n", zName); + break; + } + if( (flags & GREP_QUIET)==0 ){ + if( cnt==1 && zName ){ + fossil_print("== %s\n", zName); + } + fossil_print("%d:%.*s\n", ln, n, z+i); + } + } + } + return cnt; +} + +/* +** COMMAND: test-grep +** +** Usage: %fossil test-grep REGEXP [FILE...] +** +** Run a regular expression match over the named disk files, or against +** standard input if no disk files are named on the command-line. +** +** Options: +** -i|--ignore-case Ignore case +** --robot-exception Use the robot-exception setting as the REGEXP +*/ +void re_test_grep(void){ + ReCompiled *pRe; + const char *zErr; + int iFileList = 3; + int ignoreCase = find_option("ignore-case","i",0)!=0; + int bRobot = find_option("robot-exception",0,0)!=0; + if( bRobot ){ + const char *zRe; + db_find_and_open_repository(0,0); + verify_all_options(); + zRe = db_get("robot-exception","^$"); + zErr = fossil_re_compile(&pRe, zRe, ignoreCase); + iFileList = 2; + }else{ + verify_all_options(); + if( g.argc<3 ){ + usage("REGEXP [FILE...]"); + } + zErr = fossil_re_compile(&pRe, g.argv[2], ignoreCase); + } + if( zErr ) fossil_fatal("%s", zErr); + if( g.argc==iFileList ){ + grep_file(pRe, "-", stdin); + }else{ + int i; + for(i=iFileList; iSyntax rules for regular expression matching in Fossil:

+ @ + @ + @
   Pattern + @    Match + @
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) + @ X + @
X|Y + @ X or Y + @
^X + @ X at the beginning of the string + @
X$ + @ X at the end of the string + @
. + @ Any single character + @
\C + @ Character C if C is one of: \{}()[]|*+? + @
\C + @ C-language escapes if C is one of: afnrtv + @
\uHHHH + @ Unicode character U+HHHH where HHHH is four hex digits + @
\HH + @ Unicode character U+00HH where HH is two hex digits + @
[abc] + @ Any single character from abc + @
[^abc] + @ Any single character not in abc + @
[a-z] + @ Any single character between a and z, inclusive + @
[^a-z] + @ Any single character not between a and z + @
\b + @ Word boundary + @
\w + @ A word character: a-zA-Z0-9 or _ + @
\W + @ A non-word character + @
\d + @ A digit. 0-9 + @
\D + @ A non-digit character + @
\s + @ A whitespace character + @
\S + @ A non-whitespace character + @
+ @ + @

In the "Pattern" column of the table above:

+ @
    + @
  • "X" and "Y" mean any subpattern + @
  • "P" and "Q" mean integers + @
  • "C" means a single character + @
  • "H" means a hexadecimal digit + @
  • "abc" means any sequences of one or more characters + @
  • "a-z" means any single character, a single "-" + @ character, and then one additional character. + @
  • All other symbols in the patterns are literal text + @
+ @ + @

The "X|Y" pattern has lower precedence + @ than the others. Use "(...)" for grouping, as + @ necessary. + style_finish_page(); +} -- cgit v1.3.1