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Diffstat (limited to 'gdb/gnu-regex.c')
| -rw-r--r-- | gdb/gnu-regex.c | 1757 |
1 files changed, 1757 insertions, 0 deletions
diff --git a/gdb/gnu-regex.c b/gdb/gnu-regex.c new file mode 100644 index 0000000..062fbc6 --- /dev/null +++ b/gdb/gnu-regex.c @@ -0,0 +1,1757 @@ +/* Extended regular expression matching and search library. + Copyright (C) 1985, 1989 Free Software Foundation, Inc. + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or +(at your option) any later version. + +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. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* To test, compile with -Dtest. + This Dtestable feature turns this into a self-contained program + which reads a pattern, describes how it compiles, + then reads a string and searches for it. */ + +#ifdef emacs + +/* The `emacs' switch turns on certain special matching commands + that make sense only in emacs. */ + +#include "config.h" +#include "lisp.h" +#include "buffer.h" +#include "syntax.h" + +#else /* not emacs */ + +#include "defs.h" +#include "gdb_string.h" + +/* + * Define the syntax stuff, so we can do the \<...\> things. + */ + +#ifndef Sword /* must be non-zero in some of the tests below... */ +#define Sword 1 +#endif + +#define SYNTAX(c) re_syntax_table[c] + +#ifdef SYNTAX_TABLE + +char *re_syntax_table; + +#else + +static char re_syntax_table[256]; + +static void +init_syntax_once () +{ + register int c; + static int done = 0; + + if (done) + return; + + memset (re_syntax_table, '\0', sizeof re_syntax_table); + + for (c = 'a'; c <= 'z'; c++) + re_syntax_table[c] = Sword; + + for (c = 'A'; c <= 'Z'; c++) + re_syntax_table[c] = Sword; + + for (c = '0'; c <= '9'; c++) + re_syntax_table[c] = Sword; + + done = 1; +} + +#endif /* SYNTAX_TABLE */ +#endif /* not emacs */ + +#include "gnu-regex.h" + +/* Number of failure points to allocate space for initially, + when matching. If this number is exceeded, more space is allocated, + so it is not a hard limit. */ + +#ifndef NFAILURES +#define NFAILURES 80 +#endif /* NFAILURES */ + +/* width of a byte in bits */ + +#define BYTEWIDTH 8 + +/* We remove any previous definition of `SIGN_EXTEND_CHAR', + since ours (we hope) works properly with all combinations of + machines, compilers, `char' and `unsigned char' argument types. + (Per Bothner suggested the basic approach.) */ +#undef SIGN_EXTEND_CHAR +#if __STDC__ +#define SIGN_EXTEND_CHAR(c) ((signed char) (c)) +#else /* not __STDC__ */ +/* As in Harbison and Steele. */ +#define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128) +#endif + +static int obscure_syntax = 0; + +/* Specify the precise syntax of regexp for compilation. + This provides for compatibility for various utilities + which historically have different, incompatible syntaxes. + + The argument SYNTAX is a bit-mask containing the two bits + RE_NO_BK_PARENS and RE_NO_BK_VBAR. */ + +int +re_set_syntax (syntax) + int syntax; +{ + int ret; + + ret = obscure_syntax; + obscure_syntax = syntax; + return ret; +} + +/* re_compile_pattern takes a regular-expression string + and converts it into a buffer full of byte commands for matching. + + PATTERN is the address of the pattern string + SIZE is the length of it. + BUFP is a struct re_pattern_buffer * which points to the info + on where to store the byte commands. + This structure contains a char * which points to the + actual space, which should have been obtained with malloc. + re_compile_pattern may use realloc to grow the buffer space. + + The number of bytes of commands can be found out by looking in + the struct re_pattern_buffer that bufp pointed to, + after re_compile_pattern returns. +*/ + +#define PATPUSH(ch) (*b++ = (char) (ch)) + +#define PATFETCH(c) \ + {if (p == pend) goto end_of_pattern; \ + c = * (unsigned char *) p++; \ + if (translate) c = translate[c]; } + +#define PATFETCH_RAW(c) \ + {if (p == pend) goto end_of_pattern; \ + c = * (unsigned char *) p++; } + +#define PATUNFETCH p-- + +/* This is not an arbitrary limit: the arguments which represent offsets + into the pattern are two bytes long. So if 2^16 bytes turns out to + be too small, many things would have to change. */ +#define MAX_BUF_SIZE (1 << 16) + + +/* Extend the buffer by twice its current size via realloc and + reset the pointers that pointed into the old block to point to the + correct places in the new one. If extending the buffer results in it + being larger than MAX_BUF_SIZE, then flag memory exhausted. */ +#define EXTEND_BUFFER \ + do { \ + char *old_buffer = bufp->buffer; \ + if (bufp->allocated == MAX_BUF_SIZE) \ + goto too_big; \ + bufp->allocated <<= 1; \ + if (bufp->allocated > MAX_BUF_SIZE) \ + bufp->allocated = MAX_BUF_SIZE; \ + bufp->buffer = (char *) realloc (bufp->buffer, bufp->allocated);\ + if (bufp->buffer == NULL) \ + goto memory_exhausted; \ + /* If the buffer moved, move all the pointers into it. */ \ + if (old_buffer != bufp->buffer) \ + { \ + b = (b - old_buffer) + bufp->buffer; \ + begalt = (begalt - old_buffer) + bufp->buffer; \ + if (fixup_jump) \ + fixup_jump = (fixup_jump - old_buffer) + bufp->buffer;\ + if (laststart) \ + laststart = (laststart - old_buffer) + bufp->buffer; \ + if (pending_exact) \ + pending_exact = (pending_exact - old_buffer) + bufp->buffer; \ + } \ + } while (0) + +static void store_jump (), insert_jump (); + +char * +re_compile_pattern (pattern, size, bufp) + char *pattern; + int size; + struct re_pattern_buffer *bufp; +{ + register char *b = bufp->buffer; + register char *p = pattern; + char *pend = pattern + size; + register unsigned c, c1; + char *p1; + unsigned char *translate = (unsigned char *) bufp->translate; + + /* address of the count-byte of the most recently inserted "exactn" command. + This makes it possible to tell whether a new exact-match character + can be added to that command or requires a new "exactn" command. */ + + char *pending_exact = 0; + + /* address of the place where a forward-jump should go + to the end of the containing expression. + Each alternative of an "or", except the last, ends with a forward-jump + of this sort. */ + + char *fixup_jump = 0; + + /* address of start of the most recently finished expression. + This tells postfix * where to find the start of its operand. */ + + char *laststart = 0; + + /* In processing a repeat, 1 means zero matches is allowed */ + + char zero_times_ok; + + /* In processing a repeat, 1 means many matches is allowed */ + + char many_times_ok; + + /* address of beginning of regexp, or inside of last \( */ + + char *begalt = b; + + /* Stack of information saved by \( and restored by \). + Four stack elements are pushed by each \(: + First, the value of b. + Second, the value of fixup_jump. + Third, the value of regnum. + Fourth, the value of begalt. */ + + int stackb[40]; + int *stackp = stackb; + int *stacke = stackb + 40; + int *stackt; + + /* Counts \('s as they are encountered. Remembered for the matching \), + where it becomes the "register number" to put in the stop_memory command */ + + int regnum = 1; + + bufp->fastmap_accurate = 0; + +#ifndef emacs +#ifndef SYNTAX_TABLE + /* + * Initialize the syntax table. + */ + init_syntax_once(); +#endif +#endif + + if (bufp->allocated == 0) + { + bufp->allocated = 28; + if (bufp->buffer) + /* EXTEND_BUFFER loses when bufp->allocated is 0 */ + bufp->buffer = (char *) realloc (bufp->buffer, 28); + else + /* Caller did not allocate a buffer. Do it for him */ + bufp->buffer = (char *) malloc (28); + if (!bufp->buffer) goto memory_exhausted; + begalt = b = bufp->buffer; + } + + while (p != pend) + { + if (b - bufp->buffer > bufp->allocated - 10) + /* Note that EXTEND_BUFFER clobbers c */ + EXTEND_BUFFER; + + PATFETCH (c); + + switch (c) + { + case '$': + if (obscure_syntax & RE_TIGHT_VBAR) + { + if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS) && p != pend) + goto normal_char; + /* Make operand of last vbar end before this `$'. */ + if (fixup_jump) + store_jump (fixup_jump, jump, b); + fixup_jump = 0; + PATPUSH (endline); + break; + } + + /* $ means succeed if at end of line, but only in special contexts. + If randomly in the middle of a pattern, it is a normal character. */ + if (p == pend || *p == '\n' + || (obscure_syntax & RE_CONTEXT_INDEP_OPS) + || (obscure_syntax & RE_NO_BK_PARENS + ? *p == ')' + : *p == '\\' && p[1] == ')') + || (obscure_syntax & RE_NO_BK_VBAR + ? *p == '|' + : *p == '\\' && p[1] == '|')) + { + PATPUSH (endline); + break; + } + goto normal_char; + + case '^': + /* ^ means succeed if at beg of line, but only if no preceding pattern. */ + + if (laststart && p[-2] != '\n' + && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) + goto normal_char; + if (obscure_syntax & RE_TIGHT_VBAR) + { + if (p != pattern + 1 + && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) + goto normal_char; + PATPUSH (begline); + begalt = b; + } + else + PATPUSH (begline); + break; + + case '+': + case '?': + if (obscure_syntax & RE_BK_PLUS_QM) + goto normal_char; + handle_plus: + case '*': + /* If there is no previous pattern, char not special. */ + if (!laststart && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) + goto normal_char; + /* If there is a sequence of repetition chars, + collapse it down to equivalent to just one. */ + zero_times_ok = 0; + many_times_ok = 0; + while (1) + { + zero_times_ok |= c != '+'; + many_times_ok |= c != '?'; + if (p == pend) + break; + PATFETCH (c); + if (c == '*') + ; + else if (!(obscure_syntax & RE_BK_PLUS_QM) + && (c == '+' || c == '?')) + ; + else if ((obscure_syntax & RE_BK_PLUS_QM) + && c == '\\') + { + int c1; + PATFETCH (c1); + if (!(c1 == '+' || c1 == '?')) + { + PATUNFETCH; + PATUNFETCH; + break; + } + c = c1; + } + else + { + PATUNFETCH; + break; + } + } + + /* Star, etc. applied to an empty pattern is equivalent + to an empty pattern. */ + if (!laststart) + break; + + /* Now we know whether 0 matches is allowed, + and whether 2 or more matches is allowed. */ + if (many_times_ok) + { + /* If more than one repetition is allowed, + put in a backward jump at the end. */ + store_jump (b, maybe_finalize_jump, laststart - 3); + b += 3; + } + insert_jump (on_failure_jump, laststart, b + 3, b); + pending_exact = 0; + b += 3; + if (!zero_times_ok) + { + /* At least one repetition required: insert before the loop + a skip over the initial on-failure-jump instruction */ + insert_jump (dummy_failure_jump, laststart, laststart + 6, b); + b += 3; + } + break; + + case '.': + laststart = b; + PATPUSH (anychar); + break; + + case '[': + while (b - bufp->buffer + > bufp->allocated - 3 - (1 << BYTEWIDTH) / BYTEWIDTH) + /* Note that EXTEND_BUFFER clobbers c */ + EXTEND_BUFFER; + + laststart = b; + if (*p == '^') + PATPUSH (charset_not), p++; + else + PATPUSH (charset); + p1 = p; + + PATPUSH ((1 << BYTEWIDTH) / BYTEWIDTH); + /* Clear the whole map */ + memset (b, '\0', (1 << BYTEWIDTH) / BYTEWIDTH); + /* Read in characters and ranges, setting map bits */ + while (1) + { + PATFETCH (c); + if (c == ']' && p != p1 + 1) break; + if (*p == '-' && p[1] != ']') + { + PATFETCH (c1); + PATFETCH (c1); + while (c <= c1) + b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH), c++; + } + else + { + b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH); + } + } + /* Discard any bitmap bytes that are all 0 at the end of the map. + Decrement the map-length byte too. */ + while ((int) b[-1] > 0 && b[b[-1] - 1] == 0) + b[-1]--; + b += b[-1]; + break; + + case '(': + if (! (obscure_syntax & RE_NO_BK_PARENS)) + goto normal_char; + else + goto handle_open; + + case ')': + if (! (obscure_syntax & RE_NO_BK_PARENS)) + goto normal_char; + else + goto handle_close; + + case '\n': + if (! (obscure_syntax & RE_NEWLINE_OR)) + goto normal_char; + else + goto handle_bar; + + case '|': + if (! (obscure_syntax & RE_NO_BK_VBAR)) + goto normal_char; + else + goto handle_bar; + + case '\\': + if (p == pend) goto invalid_pattern; + PATFETCH_RAW (c); + switch (c) + { + case '(': + if (obscure_syntax & RE_NO_BK_PARENS) + goto normal_backsl; + handle_open: + if (stackp == stacke) goto nesting_too_deep; + if (regnum < RE_NREGS) + { + PATPUSH (start_memory); + PATPUSH (regnum); + } + *stackp++ = b - bufp->buffer; + *stackp++ = fixup_jump ? fixup_jump - bufp->buffer + 1 : 0; + *stackp++ = regnum++; + *stackp++ = begalt - bufp->buffer; + fixup_jump = 0; + laststart = 0; + begalt = b; + break; + + case ')': + if (obscure_syntax & RE_NO_BK_PARENS) + goto normal_backsl; + handle_close: + if (stackp == stackb) goto unmatched_close; + begalt = *--stackp + bufp->buffer; + if (fixup_jump) + store_jump (fixup_jump, jump, b); + if (stackp[-1] < RE_NREGS) + { + PATPUSH (stop_memory); + PATPUSH (stackp[-1]); + } + stackp -= 2; + fixup_jump = 0; + if (*stackp) + fixup_jump = *stackp + bufp->buffer - 1; + laststart = *--stackp + bufp->buffer; + break; + + case '|': + if (obscure_syntax & RE_NO_BK_VBAR) + goto normal_backsl; + handle_bar: + insert_jump (on_failure_jump, begalt, b + 6, b); + pending_exact = 0; + b += 3; + if (fixup_jump) + store_jump (fixup_jump, jump, b); + fixup_jump = b; + b += 3; + laststart = 0; + begalt = b; + break; + +#ifdef emacs + case '=': + PATPUSH (at_dot); + break; + + case 's': + laststart = b; + PATPUSH (syntaxspec); + PATFETCH (c); + PATPUSH (syntax_spec_code[c]); + break; + + case 'S': + laststart = b; + PATPUSH (notsyntaxspec); + PATFETCH (c); + PATPUSH (syntax_spec_code[c]); + break; +#endif /* emacs */ + + case 'w': + laststart = b; + PATPUSH (wordchar); + break; + + case 'W': + laststart = b; + PATPUSH (notwordchar); + break; + + case '<': + PATPUSH (wordbeg); + break; + + case '>': + PATPUSH (wordend); + break; + + case 'b': + PATPUSH (wordbound); + break; + + case 'B': + PATPUSH (notwordbound); + break; + + case '`': + PATPUSH (begbuf); + break; + + case '\'': + PATPUSH (endbuf); + break; + + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + c1 = c - '0'; + if (c1 >= regnum) + goto normal_char; + for (stackt = stackp - 2; stackt > stackb; stackt -= 4) + if (*stackt == c1) + goto normal_char; + laststart = b; + PATPUSH (duplicate); + PATPUSH (c1); + break; + + case '+': + case '?': + if (obscure_syntax & RE_BK_PLUS_QM) + goto handle_plus; + + default: + normal_backsl: + /* You might think it would be useful for \ to mean + not to translate; but if we don't translate it + it will never match anything. */ + if (translate) c = translate[c]; + goto normal_char; + } + break; + + default: + normal_char: + if (!pending_exact || pending_exact + *pending_exact + 1 != b + || *pending_exact == 0177 || *p == '*' || *p == '^' + || ((obscure_syntax & RE_BK_PLUS_QM) + ? *p == '\\' && (p[1] == '+' || p[1] == '?') + : (*p == '+' || *p == '?'))) + { + laststart = b; + PATPUSH (exactn); + pending_exact = b; + PATPUSH (0); + } + PATPUSH (c); + (*pending_exact)++; + } + } + + if (fixup_jump) + store_jump (fixup_jump, jump, b); + + if (stackp != stackb) goto unmatched_open; + + bufp->used = b - bufp->buffer; + return 0; + + invalid_pattern: + return "Invalid regular expression"; + + unmatched_open: + return "Unmatched \\("; + + unmatched_close: + return "Unmatched \\)"; + + end_of_pattern: + return "Premature end of regular expression"; + + nesting_too_deep: + return "Nesting too deep"; + + too_big: + return "Regular expression too big"; + + memory_exhausted: + return "Memory exhausted"; +} + +/* Store where `from' points a jump operation to jump to where `to' points. + `opcode' is the opcode to store. */ + +static void +store_jump (from, opcode, to) + char *from, *to; + char opcode; +{ + from[0] = opcode; + from[1] = (to - (from + 3)) & 0377; + from[2] = (to - (from + 3)) >> 8; +} + +/* Open up space at char FROM, and insert there a jump to TO. + CURRENT_END gives te end of the storage no in use, + so we know how much data to copy up. + OP is the opcode of the jump to insert. + + If you call this function, you must zero out pending_exact. */ + +static void +insert_jump (op, from, to, current_end) + char op; + char *from, *to, *current_end; +{ + register char *pto = current_end + 3; + register char *pfrom = current_end; + while (pfrom != from) + *--pto = *--pfrom; + store_jump (from, op, to); +} + +/* Given a pattern, compute a fastmap from it. + The fastmap records which of the (1 << BYTEWIDTH) possible characters + can start a string that matches the pattern. + This fastmap is used by re_search to skip quickly over totally implausible text. + + The caller must supply the address of a (1 << BYTEWIDTH)-byte data area + as bufp->fastmap. + The other components of bufp describe the pattern to be used. */ + +void +re_compile_fastmap (bufp) + struct re_pattern_buffer *bufp; +{ + unsigned char *pattern = (unsigned char *) bufp->buffer; + int size = bufp->used; + register char *fastmap = bufp->fastmap; + register unsigned char *p = pattern; + register unsigned char *pend = pattern + size; + register int j; + unsigned char *translate = (unsigned char *) bufp->translate; + + unsigned char *stackb[NFAILURES]; + unsigned char **stackp = stackb; + + memset (fastmap, '\0', (1 << BYTEWIDTH)); + bufp->fastmap_accurate = 1; + bufp->can_be_null = 0; + + while (p) + { + if (p == pend) + { + bufp->can_be_null = 1; + break; + } +#ifdef SWITCH_ENUM_BUG + switch ((int) ((enum regexpcode) *p++)) +#else + switch ((enum regexpcode) *p++) +#endif + { + case exactn: + if (translate) + fastmap[translate[p[1]]] = 1; + else + fastmap[p[1]] = 1; + break; + + case begline: + case before_dot: + case at_dot: + case after_dot: + case begbuf: + case endbuf: + case wordbound: + case notwordbound: + case wordbeg: + case wordend: + continue; + + case endline: + if (translate) + fastmap[translate['\n']] = 1; + else + fastmap['\n'] = 1; + if (bufp->can_be_null != 1) + bufp->can_be_null = 2; + break; + + case finalize_jump: + case maybe_finalize_jump: + case jump: + case dummy_failure_jump: + bufp->can_be_null = 1; + j = *p++ & 0377; + j += SIGN_EXTEND_CHAR (*(char *)p) << 8; + p += j + 1; /* The 1 compensates for missing ++ above */ + if (j > 0) + continue; + /* Jump backward reached implies we just went through + the body of a loop and matched nothing. + Opcode jumped to should be an on_failure_jump. + Just treat it like an ordinary jump. + For a * loop, it has pushed its failure point already; + if so, discard that as redundant. */ + if ((enum regexpcode) *p != on_failure_jump) + continue; + p++; + j = *p++ & 0377; + j += SIGN_EXTEND_CHAR (*(char *)p) << 8; + p += j + 1; /* The 1 compensates for missing ++ above */ + if (stackp != stackb && *stackp == p) + stackp--; + continue; + + case on_failure_jump: + j = *p++ & 0377; + j += SIGN_EXTEND_CHAR (*(char *)p) << 8; + p++; + *++stackp = p + j; + continue; + + case start_memory: + case stop_memory: + p++; + continue; + + case duplicate: + bufp->can_be_null = 1; + fastmap['\n'] = 1; + case anychar: + for (j = 0; j < (1 << BYTEWIDTH); j++) + if (j != '\n') + fastmap[j] = 1; + if (bufp->can_be_null) + return; + /* Don't return; check the alternative paths + so we can set can_be_null if appropriate. */ + break; + + case wordchar: + for (j = 0; j < (1 << BYTEWIDTH); j++) + if (SYNTAX (j) == Sword) + fastmap[j] = 1; + break; + + case notwordchar: + for (j = 0; j < (1 << BYTEWIDTH); j++) + if (SYNTAX (j) != Sword) + fastmap[j] = 1; + break; + +#ifdef emacs + case syntaxspec: + k = *p++; + for (j = 0; j < (1 << BYTEWIDTH); j++) + if (SYNTAX (j) == (enum syntaxcode) k) + fastmap[j] = 1; + break; + + case notsyntaxspec: + k = *p++; + for (j = 0; j < (1 << BYTEWIDTH); j++) + if (SYNTAX (j) != (enum syntaxcode) k) + fastmap[j] = 1; + break; +#endif /* emacs */ + + case charset: + for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) + if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) + { + if (translate) + fastmap[translate[j]] = 1; + else + fastmap[j] = 1; + } + break; + + case charset_not: + /* Chars beyond end of map must be allowed */ + for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++) + if (translate) + fastmap[translate[j]] = 1; + else + fastmap[j] = 1; + + for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) + if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))) + { + if (translate) + fastmap[translate[j]] = 1; + else + fastmap[j] = 1; + } + break; + case unused: + case syntaxspec: + case notsyntaxspec: + default: + break; + } + + /* Get here means we have successfully found the possible starting characters + of one path of the pattern. We need not follow this path any farther. + Instead, look at the next alternative remembered in the stack. */ + if (stackp != stackb) + p = *stackp--; + else + break; + } +} + +/* Like re_search_2, below, but only one string is specified. */ + +int +re_search (pbufp, string, size, startpos, range, regs) + struct re_pattern_buffer *pbufp; + char *string; + int size, startpos, range; + struct re_registers *regs; +{ + return re_search_2 (pbufp, 0, 0, string, size, startpos, range, regs, size); +} + +/* Like re_match_2 but tries first a match starting at index STARTPOS, + then at STARTPOS + 1, and so on. + RANGE is the number of places to try before giving up. + If RANGE is negative, the starting positions tried are + STARTPOS, STARTPOS - 1, etc. + It is up to the caller to make sure that range is not so large + as to take the starting position outside of the input strings. + +The value returned is the position at which the match was found, + or -1 if no match was found, + or -2 if error (such as failure stack overflow). */ + +int +re_search_2 (pbufp, string1, size1, string2, size2, startpos, range, regs, mstop) + struct re_pattern_buffer *pbufp; + char *string1, *string2; + int size1, size2; + int startpos; + register int range; + struct re_registers *regs; + int mstop; +{ + register char *fastmap = pbufp->fastmap; + register unsigned char *translate = (unsigned char *) pbufp->translate; + int total = size1 + size2; + int val; + + /* Update the fastmap now if not correct already */ + if (fastmap && !pbufp->fastmap_accurate) + re_compile_fastmap (pbufp); + + /* Don't waste time in a long search for a pattern + that says it is anchored. */ + if (pbufp->used > 0 && (enum regexpcode) pbufp->buffer[0] == begbuf + && range > 0) + { + if (startpos > 0) + return -1; + else + range = 1; + } + + while (1) + { + /* If a fastmap is supplied, skip quickly over characters + that cannot possibly be the start of a match. + Note, however, that if the pattern can possibly match + the null string, we must test it at each starting point + so that we take the first null string we get. */ + + if (fastmap && startpos < total && pbufp->can_be_null != 1) + { + if (range > 0) + { + register int lim = 0; + register unsigned char *p; + int irange = range; + if (startpos < size1 && startpos + range >= size1) + lim = range - (size1 - startpos); + + p = ((unsigned char *) + &(startpos >= size1 ? string2 - size1 : string1)[startpos]); + + if (translate) + { + while (range > lim && !fastmap[translate[*p++]]) + range--; + } + else + { + while (range > lim && !fastmap[*p++]) + range--; + } + startpos += irange - range; + } + else + { + register unsigned char c; + if (startpos >= size1) + c = string2[startpos - size1]; + else + c = string1[startpos]; + c &= 0xff; + if (translate ? !fastmap[translate[c]] : !fastmap[c]) + goto advance; + } + } + + if (range >= 0 && startpos == total + && fastmap && pbufp->can_be_null == 0) + return -1; + + val = re_match_2 (pbufp, string1, size1, string2, size2, startpos, regs, mstop); + if (0 <= val) + { + if (val == -2) + return -2; + return startpos; + } + +#ifdef C_ALLOCA + alloca (0); +#endif /* C_ALLOCA */ + + advance: + if (!range) break; + if (range > 0) range--, startpos++; else range++, startpos--; + } + return -1; +} + +#ifndef emacs /* emacs never uses this */ +int +re_match (pbufp, string, size, pos, regs) + struct re_pattern_buffer *pbufp; + char *string; + int size, pos; + struct re_registers *regs; +{ + return re_match_2 (pbufp, 0, 0, string, size, pos, regs, size); +} +#endif /* emacs */ + +/* Maximum size of failure stack. Beyond this, overflow is an error. */ + +int re_max_failures = 2000; + +static int memcmp_translate(); +/* Match the pattern described by PBUFP + against data which is the virtual concatenation of STRING1 and STRING2. + SIZE1 and SIZE2 are the sizes of the two data strings. + Start the match at position POS. + Do not consider matching past the position MSTOP. + + If pbufp->fastmap is nonzero, then it had better be up to date. + + The reason that the data to match are specified as two components + which are to be regarded as concatenated + is so this function can be used directly on the contents of an Emacs buffer. + + -1 is returned if there is no match. -2 is returned if there is + an error (such as match stack overflow). Otherwise the value is the length + of the substring which was matched. */ + +int +re_match_2 (pbufp, string1, size1, string2, size2, pos, regs, mstop) + struct re_pattern_buffer *pbufp; + unsigned char *string1, *string2; + int size1, size2; + int pos; + struct re_registers *regs; + int mstop; +{ + register unsigned char *p = (unsigned char *) pbufp->buffer; + register unsigned char *pend = p + pbufp->used; + /* End of first string */ + unsigned char *end1; + /* End of second string */ + unsigned char *end2; + /* Pointer just past last char to consider matching */ + unsigned char *end_match_1, *end_match_2; + register unsigned char *d, *dend; + register int mcnt; + unsigned char *translate = (unsigned char *) pbufp->translate; + + /* Failure point stack. Each place that can handle a failure further down the line + pushes a failure point on this stack. It consists of two char *'s. + The first one pushed is where to resume scanning the pattern; + the second pushed is where to resume scanning the strings. + If the latter is zero, the failure point is a "dummy". + If a failure happens and the innermost failure point is dormant, + it discards that failure point and tries the next one. */ + + unsigned char *initial_stack[2 * NFAILURES]; + unsigned char **stackb = initial_stack; + unsigned char **stackp = stackb, **stacke = &stackb[2 * NFAILURES]; + + /* Information on the "contents" of registers. + These are pointers into the input strings; they record + just what was matched (on this attempt) by some part of the pattern. + The start_memory command stores the start of a register's contents + and the stop_memory command stores the end. + + At that point, regstart[regnum] points to the first character in the register, + regend[regnum] points to the first character beyond the end of the register, + regstart_seg1[regnum] is true iff regstart[regnum] points into string1, + and regend_seg1[regnum] is true iff regend[regnum] points into string1. */ + + unsigned char *regstart[RE_NREGS]; + unsigned char *regend[RE_NREGS]; + unsigned char regstart_seg1[RE_NREGS], regend_seg1[RE_NREGS]; + + /* Set up pointers to ends of strings. + Don't allow the second string to be empty unless both are empty. */ + if (!size2) + { + string2 = string1; + size2 = size1; + string1 = 0; + size1 = 0; + } + end1 = string1 + size1; + end2 = string2 + size2; + + /* Compute where to stop matching, within the two strings */ + if (mstop <= size1) + { + end_match_1 = string1 + mstop; + end_match_2 = string2; + } + else + { + end_match_1 = end1; + end_match_2 = string2 + mstop - size1; + } + + /* Initialize \) text positions to -1 + to mark ones that no \( or \) has been seen for. */ + + for (mcnt = 0; mcnt < sizeof (regend) / sizeof (*regend); mcnt++) + regend[mcnt] = (unsigned char *) -1; + + /* `p' scans through the pattern as `d' scans through the data. + `dend' is the end of the input string that `d' points within. + `d' is advanced into the following input string whenever necessary, + but this happens before fetching; + therefore, at the beginning of the loop, + `d' can be pointing at the end of a string, + but it cannot equal string2. */ + + if (pos <= size1) + d = string1 + pos, dend = end_match_1; + else + d = string2 + pos - size1, dend = end_match_2; + +/* Write PREFETCH; just before fetching a character with *d. */ +#define PREFETCH \ + while (d == dend) \ + { if (dend == end_match_2) goto fail; /* end of string2 => failure */ \ + d = string2; /* end of string1 => advance to string2. */ \ + dend = end_match_2; } + + /* This loop loops over pattern commands. + It exits by returning from the function if match is complete, + or it drops through if match fails at this starting point in the input data. */ + + while (1) + { + if (p == pend) + /* End of pattern means we have succeeded! */ + { + /* If caller wants register contents data back, convert it to indices */ + if (regs) + { + regs->start[0] = pos; + if (dend == end_match_1) + regs->end[0] = d - string1; + else + regs->end[0] = d - string2 + size1; + for (mcnt = 1; mcnt < RE_NREGS; mcnt++) + { + if (regend[mcnt] == (unsigned char *) -1) + { + regs->start[mcnt] = -1; + regs->end[mcnt] = -1; + continue; + } + if (regstart_seg1[mcnt]) + regs->start[mcnt] = regstart[mcnt] - string1; + else + regs->start[mcnt] = regstart[mcnt] - string2 + size1; + if (regend_seg1[mcnt]) + regs->end[mcnt] = regend[mcnt] - string1; + else + regs->end[mcnt] = regend[mcnt] - string2 + size1; + } + } + if (dend == end_match_1) + return (d - string1 - pos); + else + return d - string2 + size1 - pos; + } + + /* Otherwise match next pattern command */ +#ifdef SWITCH_ENUM_BUG + switch ((int) ((enum regexpcode) *p++)) +#else + switch ((enum regexpcode) *p++) +#endif + { + + /* \( is represented by a start_memory, \) by a stop_memory. + Both of those commands contain a "register number" argument. + The text matched within the \( and \) is recorded under that number. + Then, \<digit> turns into a `duplicate' command which + is followed by the numeric value of <digit> as the register number. */ + + case start_memory: + regstart[*p] = d; + regstart_seg1[*p++] = (dend == end_match_1); + break; + + case stop_memory: + regend[*p] = d; + regend_seg1[*p++] = (dend == end_match_1); + break; + + case duplicate: + { + int regno = *p++; /* Get which register to match against */ + register unsigned char *d2, *dend2; + + d2 = regstart[regno]; + dend2 = ((regstart_seg1[regno] == regend_seg1[regno]) + ? regend[regno] : end_match_1); + while (1) + { + /* Advance to next segment in register contents, if necessary */ + while (d2 == dend2) + { + if (dend2 == end_match_2) break; + if (dend2 == regend[regno]) break; + d2 = string2, dend2 = regend[regno]; /* end of string1 => advance to string2. */ + } + /* At end of register contents => success */ + if (d2 == dend2) break; + + /* Advance to next segment in data being matched, if necessary */ + PREFETCH; + + /* mcnt gets # consecutive chars to compare */ + mcnt = dend - d; + if (mcnt > dend2 - d2) + mcnt = dend2 - d2; + /* Compare that many; failure if mismatch, else skip them. */ + if (translate ? memcmp_translate (d, d2, mcnt, translate) : memcmp (d, d2, mcnt)) + goto fail; + d += mcnt, d2 += mcnt; + } + } + break; + + case anychar: + /* fetch a data character */ + PREFETCH; + /* Match anything but a newline. */ + if ((translate ? translate[*d++] : *d++) == '\n') + goto fail; + break; + + case charset: + case charset_not: + { + /* Nonzero for charset_not */ + int not = 0; + register int c; + if (*(p - 1) == (unsigned char) charset_not) + not = 1; + + /* fetch a data character */ + PREFETCH; + + if (translate) + c = translate [*d]; + else + c = *d; + + if (c < *p * BYTEWIDTH + && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) + not = !not; + + p += 1 + *p; + + if (!not) goto fail; + d++; + break; + } + + case begline: + if (d == string1 || d[-1] == '\n') + break; + goto fail; + + case endline: + if (d == end2 + || (d == end1 ? (size2 == 0 || *string2 == '\n') : *d == '\n')) + break; + goto fail; + + /* "or" constructs ("|") are handled by starting each alternative + with an on_failure_jump that points to the start of the next alternative. + Each alternative except the last ends with a jump to the joining point. + (Actually, each jump except for the last one really jumps + to the following jump, because tensioning the jumps is a hassle.) */ + + /* The start of a stupid repeat has an on_failure_jump that points + past the end of the repeat text. + This makes a failure point so that, on failure to match a repetition, + matching restarts past as many repetitions have been found + with no way to fail and look for another one. */ + + /* A smart repeat is similar but loops back to the on_failure_jump + so that each repetition makes another failure point. */ + + case on_failure_jump: + if (stackp == stacke) + { + unsigned char **stackx; + if (stacke - stackb > re_max_failures * 2) + return -2; + stackx = (unsigned char **) alloca (2 * (stacke - stackb) + * sizeof (char *)); + memcpy (stackx, stackb, (stacke - stackb) * sizeof (char *)); + stackp = stackx + (stackp - stackb); + stacke = stackx + 2 * (stacke - stackb); + stackb = stackx; + } + mcnt = *p++ & 0377; + mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; + p++; + *stackp++ = mcnt + p; + *stackp++ = d; + break; + + /* The end of a smart repeat has an maybe_finalize_jump back. + Change it either to a finalize_jump or an ordinary jump. */ + + case maybe_finalize_jump: + mcnt = *p++ & 0377; + mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; + p++; + { + register unsigned char *p2 = p; + /* Compare what follows with the begining of the repeat. + If we can establish that there is nothing that they would + both match, we can change to finalize_jump */ + while (p2 != pend + && (*p2 == (unsigned char) stop_memory + || *p2 == (unsigned char) start_memory)) + p2++; + if (p2 == pend) + p[-3] = (unsigned char) finalize_jump; + else if (*p2 == (unsigned char) exactn + || *p2 == (unsigned char) endline) + { + register int c = *p2 == (unsigned char) endline ? '\n' : p2[2]; + register unsigned char *p1 = p + mcnt; + /* p1[0] ... p1[2] are an on_failure_jump. + Examine what follows that */ + if (p1[3] == (unsigned char) exactn && p1[5] != c) + p[-3] = (unsigned char) finalize_jump; + else if (p1[3] == (unsigned char) charset + || p1[3] == (unsigned char) charset_not) + { + int not = p1[3] == (unsigned char) charset_not; + if (c < p1[4] * BYTEWIDTH + && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) + not = !not; + /* not is 1 if c would match */ + /* That means it is not safe to finalize */ + if (!not) + p[-3] = (unsigned char) finalize_jump; + } + } + } + p -= 2; + if (p[-1] != (unsigned char) finalize_jump) + { + p[-1] = (unsigned char) jump; + goto nofinalize; + } + + /* The end of a stupid repeat has a finalize-jump + back to the start, where another failure point will be made + which will point after all the repetitions found so far. */ + + case finalize_jump: + stackp -= 2; + + case jump: + nofinalize: + mcnt = *p++ & 0377; + mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; + p += mcnt + 1; /* The 1 compensates for missing ++ above */ + break; + + case dummy_failure_jump: + if (stackp == stacke) + { + unsigned char **stackx + = (unsigned char **) alloca (2 * (stacke - stackb) + * sizeof (char *)); + memcpy (stackx, stackb, (stacke - stackb) * sizeof (char *)); + stackp = stackx + (stackp - stackb); + stacke = stackx + 2 * (stacke - stackb); + stackb = stackx; + } + *stackp++ = 0; + *stackp++ = 0; + goto nofinalize; + + case wordbound: + if (d == string1 /* Points to first char */ + || d == end2 /* Points to end */ + || (d == end1 && size2 == 0)) /* Points to end */ + break; + if ((SYNTAX (d[-1]) == Sword) + != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) + break; + goto fail; + + case notwordbound: + if (d == string1 /* Points to first char */ + || d == end2 /* Points to end */ + || (d == end1 && size2 == 0)) /* Points to end */ + goto fail; + if ((SYNTAX (d[-1]) == Sword) + != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) + goto fail; + break; + + case wordbeg: + if (d == end2 /* Points to end */ + || (d == end1 && size2 == 0) /* Points to end */ + || SYNTAX (* (d == end1 ? string2 : d)) != Sword) /* Next char not a letter */ + goto fail; + if (d == string1 /* Points to first char */ + || SYNTAX (d[-1]) != Sword) /* prev char not letter */ + break; + goto fail; + + case wordend: + if (d == string1 /* Points to first char */ + || SYNTAX (d[-1]) != Sword) /* prev char not letter */ + goto fail; + if (d == end2 /* Points to end */ + || (d == end1 && size2 == 0) /* Points to end */ + || SYNTAX (d == end1 ? *string2 : *d) != Sword) /* Next char not a letter */ + break; + goto fail; + +#ifdef emacs + case before_dot: + if (((d - string2 <= (unsigned) size2) + ? d - bf_p2 : d - bf_p1) + <= point) + goto fail; + break; + + case at_dot: + if (((d - string2 <= (unsigned) size2) + ? d - bf_p2 : d - bf_p1) + == point) + goto fail; + break; + + case after_dot: + if (((d - string2 <= (unsigned) size2) + ? d - bf_p2 : d - bf_p1) + >= point) + goto fail; + break; + + case wordchar: + mcnt = (int) Sword; + goto matchsyntax; + + case syntaxspec: + mcnt = *p++; + matchsyntax: + PREFETCH; + if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail; + break; + + case notwordchar: + mcnt = (int) Sword; + goto matchnotsyntax; + + case notsyntaxspec: + mcnt = *p++; + matchnotsyntax: + PREFETCH; + if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail; + break; +#else + case wordchar: + PREFETCH; + if (SYNTAX (*d++) == 0) goto fail; + break; + + case notwordchar: + PREFETCH; + if (SYNTAX (*d++) != 0) goto fail; + break; +#endif /* not emacs */ + + case begbuf: + if (d == string1) /* Note, d cannot equal string2 */ + break; /* unless string1 == string2. */ + goto fail; + + case endbuf: + if (d == end2 || (d == end1 && size2 == 0)) + break; + goto fail; + + case exactn: + /* Match the next few pattern characters exactly. + mcnt is how many characters to match. */ + mcnt = *p++; + if (translate) + { + do + { + PREFETCH; + if (translate[*d++] != *p++) goto fail; + } + while (--mcnt); + } + else + { + do + { + PREFETCH; + if (*d++ != *p++) goto fail; + } + while (--mcnt); + } + break; + case unused: + case before_dot: + case at_dot: + case after_dot: + case syntaxspec: + case notsyntaxspec: + default: + break; + } + continue; /* Successfully matched one pattern command; keep matching */ + + /* Jump here if any matching operation fails. */ + fail: + if (stackp != stackb) + /* A restart point is known. Restart there and pop it. */ + { + if (!stackp[-2]) + { /* If innermost failure point is dormant, flush it and keep looking */ + stackp -= 2; + goto fail; + } + d = *--stackp; + p = *--stackp; + if (d >= string1 && d <= end1) + dend = end_match_1; + } + else break; /* Matching at this starting point really fails! */ + } + return -1; /* Failure to match */ +} + +static int +memcmp_translate (s1, s2, len, translate) + unsigned char *s1, *s2; + register int len; + unsigned char *translate; +{ + register unsigned char *p1 = s1, *p2 = s2; + while (len) + { + if (translate [*p1++] != translate [*p2++]) return 1; + len--; + } + return 0; +} + +/* Entry points compatible with bsd4.2 regex library */ + +#ifndef emacs + +static struct re_pattern_buffer re_comp_buf; + +char * +re_comp (s) + const char *s; +{ + if (!s) + { + if (!re_comp_buf.buffer) + return "No previous regular expression"; + return 0; + } + + if (!re_comp_buf.buffer) + { + if (!(re_comp_buf.buffer = (char *) malloc (200))) + return "Memory exhausted"; + re_comp_buf.allocated = 200; + if (!(re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH))) + return "Memory exhausted"; + } + return re_compile_pattern (s, strlen (s), &re_comp_buf); +} + +int +re_exec (s) + char *s; +{ + int len = strlen (s); + return 0 <= re_search (&re_comp_buf, s, len, 0, len, 0); +} + +#endif /* emacs */ + +#ifdef test + +#include <stdio.h> + +/* Indexed by a character, gives the upper case equivalent of the character */ + +static char upcase[0400] = + { 000, 001, 002, 003, 004, 005, 006, 007, + 010, 011, 012, 013, 014, 015, 016, 017, + 020, 021, 022, 023, 024, 025, 026, 027, + 030, 031, 032, 033, 034, 035, 036, 037, + 040, 041, 042, 043, 044, 045, 046, 047, + 050, 051, 052, 053, 054, 055, 056, 057, + 060, 061, 062, 063, 064, 065, 066, 067, + 070, 071, 072, 073, 074, 075, 076, 077, + 0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107, + 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, + 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, + 0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137, + 0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107, + 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, + 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, + 0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177, + 0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, + 0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217, + 0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227, + 0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237, + 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, + 0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257, + 0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267, + 0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277, + 0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307, + 0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317, + 0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327, + 0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337, + 0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347, + 0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357, + 0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367, + 0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377 + }; + +main (argc, argv) + int argc; + char **argv; +{ + char pat[80]; + struct re_pattern_buffer buf; + int i; + char c; + char fastmap[(1 << BYTEWIDTH)]; + + /* Allow a command argument to specify the style of syntax. */ + if (argc > 1) + obscure_syntax = atoi (argv[1]); + + buf.allocated = 40; + buf.buffer = (char *) malloc (buf.allocated); + buf.fastmap = fastmap; + buf.translate = upcase; + + while (1) + { + gets (pat); + + if (*pat) + { + re_compile_pattern (pat, strlen(pat), &buf); + + for (i = 0; i < buf.used; i++) + printchar (buf.buffer[i]); + + putchar_unfiltered ('\n'); + + printf_unfiltered ("%d allocated, %d used.\n", buf.allocated, buf.used); + + re_compile_fastmap (&buf); + printf_unfiltered ("Allowed by fastmap: "); + for (i = 0; i < (1 << BYTEWIDTH); i++) + if (fastmap[i]) printchar (i); + putchar_unfiltered ('\n'); + } + + gets (pat); /* Now read the string to match against */ + + i = re_match (&buf, pat, strlen (pat), 0, 0); + printf_unfiltered ("Match value %d.\n", i); + } +} + +#ifdef NOTDEF +print_buf (bufp) + struct re_pattern_buffer *bufp; +{ + int i; + + printf_unfiltered ("buf is :\n----------------\n"); + for (i = 0; i < bufp->used; i++) + printchar (bufp->buffer[i]); + + printf_unfiltered ("\n%d allocated, %d used.\n", bufp->allocated, bufp->used); + + printf_unfiltered ("Allowed by fastmap: "); + for (i = 0; i < (1 << BYTEWIDTH); i++) + if (bufp->fastmap[i]) + printchar (i); + printf_unfiltered ("\nAllowed by translate: "); + if (bufp->translate) + for (i = 0; i < (1 << BYTEWIDTH); i++) + if (bufp->translate[i]) + printchar (i); + printf_unfiltered ("\nfastmap is%s accurate\n", bufp->fastmap_accurate ? "" : "n't"); + printf_unfiltered ("can %s be null\n----------", bufp->can_be_null ? "" : "not"); +} +#endif + +printchar (c) + char c; +{ + if (c < 041 || c >= 0177) + { + putchar_unfiltered ('\\'); + putchar_unfiltered (((c >> 6) & 3) + '0'); + putchar_unfiltered (((c >> 3) & 7) + '0'); + putchar_unfiltered ((c & 7) + '0'); + } + else + putchar_unfiltered (c); +} + +error (string) + char *string; +{ + puts_unfiltered (string); + exit (1); +} + +#endif /* test */ |