673 lines
13 KiB
C
673 lines
13 KiB
C
// Copyright 2007-2009 Russ Cox. All Rights Reserved.
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// Use of this source code is governed by a BSD-style
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdarg.h>
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#include <ctype.h>
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#define nelem(x) (sizeof(x)/sizeof((x)[0]))
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typedef struct rinst rinst;
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struct rinst
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{
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int opcode;
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int c;
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int n;
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rinst *x;
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rinst *y;
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};
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typedef struct rprog rprog;
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struct rprog
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{
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rinst *start;
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int len;
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};
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typedef struct rcode rcode;
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struct rcode
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{
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int unilen;
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int len;
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int sub;
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int insts[];
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};
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enum /* rinst.opcode */
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{
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// Instructions which consume input bytes (and thus fail if none left)
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CHAR = 1,
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ANY,
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CLASS,
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CLASSNOT,
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NAMEDCLASS,
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// Assert position
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BOL,
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EOL,
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// Instructions which take relative offset as arg
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JMP,
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SPLIT,
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RSPLIT,
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// Other (special) instructions
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SAVE,
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MATCH,
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};
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// Return codes for re_sizecode() and re_comp()
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enum {
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RE_SUCCESS = 0,
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RE_SYNTAX_ERROR = -2,
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RE_UNSUPPORTED_ESCAPE = -3,
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RE_UNSUPPORTED_SYNTAX = -4,
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};
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#define inst_is_consumer(inst) ((inst) < BOL)
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typedef struct rsub rsub;
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struct rsub
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{
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int ref;
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int nsub;
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const char *sub[128];
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};
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typedef struct rthread rthread;
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struct rthread
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{
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int *pc;
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rsub *sub;
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};
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typedef struct rthreadlist rthreadlist;
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struct rthreadlist
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{
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int n;
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rthread t[1];
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};
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#define INSERT_CODE(at, num, pc) \
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if (code) \
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memmove(code + at + num, code + at, (pc - at)*sizeof(int)); \
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pc += num;
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#define REL(at, to) (to - at - 2)
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#define EMIT(at, byte) (code ? (code[at] = byte) : at)
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#define PC (prog->unilen)
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void re_fatal(char *msg)
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{
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fprintf(stderr, "fatal error: %s\n", msg);
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exit(2);
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}
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static rsub *freesub;
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static rsub subs[10];
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static int subidx;
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rsub* newsub(int n)
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{
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rsub *s = freesub;
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if(s != NULL)
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freesub = (rsub*)s->sub[0];
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else
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s = &subs[subidx++];
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s->nsub = n;
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s->ref = 1;
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return s;
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}
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rsub* update(rsub *s, int i, const char *p)
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{
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rsub *s1;
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int j;
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if(s->ref > 1) {
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s1 = newsub(s->nsub);
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for(j=0; j<s->nsub; j++)
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s1->sub[j] = s->sub[j];
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s->ref--;
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s = s1;
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}
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s->sub[i] = p;
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return s;
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}
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void decref(rsub *s)
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{
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if(--s->ref == 0) {
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s->sub[0] = (char*)freesub;
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freesub = s;
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}
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}
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int re_classmatch(const int *pc, const char *sp)
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{
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// pc points to "cnt" byte after opcode
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int is_positive = (pc[-1] == CLASS);
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int cnt = *pc++;
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while (cnt--) {
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if (*sp >= *pc && *sp <= pc[1]) return is_positive;
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pc += 2;
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}
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return !is_positive;
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}
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int re_namedclassmatch(const int *pc, const char *sp)
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{
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// pc points to name of class
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int off = (*pc >> 5) & 1;
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if ((*pc | 0x20) == 'd') {
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if (!(*sp >= '0' && *sp <= '9'))
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off ^= 1;
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} else if ((*pc | 0x20) == 's') {
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if (!(*sp == ' ' || (*sp >= '\t' && *sp <= '\r')))
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off ^= 1;
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} else { // w
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if (!((*sp >= 'A' && *sp <= 'Z') || (*sp >= 'a' && *sp <= 'z') ||
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(*sp >= '0' && *sp <= '9') || *sp == '_'))
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off ^= 1;
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}
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return off;
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}
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void re_dumpcode(rcode *prog)
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{
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int pc = 0;
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int *code = prog->insts;
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while (pc < prog->unilen) {
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printf("%4d: ", pc);
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switch(code[pc++]) {
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default:
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pc = prog->unilen;
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break;
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case SPLIT:
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printf("split %d (%d)\n", pc + code[pc] + 1, code[pc]);
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pc++;
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break;
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case RSPLIT:
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printf("rsplit %d (%d)\n", pc + code[pc] + 1, code[pc]);
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pc++;
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break;
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case JMP:
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printf("jmp %d (%d)\n", pc + code[pc] + 1, code[pc]);
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pc++;
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break;
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case CHAR:
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printf("char %c\n", code[pc]);
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pc++;
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break;
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case ANY:
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printf("any\n");
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break;
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case CLASS:
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case CLASSNOT:;
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int num = code[pc];
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printf("class%s %d", (code[pc - 1] == CLASSNOT ? "not" : ""), num);
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pc++;
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while (num--) {
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printf(" 0x%02x-0x%02x", code[pc], code[pc + 1]);
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pc += 2;
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}
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printf("\n");
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break;
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case NAMEDCLASS:
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printf("namedclass %c\n", code[pc++]);
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break;
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case MATCH:
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printf("match\n");
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break;
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case SAVE:
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printf("save %d\n", code[pc++]);
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break;
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case BOL:
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printf("assert bol\n");
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break;
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case EOL:
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printf("assert eol\n");
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break;
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}
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}
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printf("Unilen: %d, insts: %d\n", prog->unilen, prog->len);
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}
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static int _compilecode(const char **re_loc, rcode *prog, int sizecode)
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{
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const char *re = *re_loc;
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int *code = sizecode ? NULL : prog->insts;
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int start = PC;
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int term = PC;
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int alt_label = 0;
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for (; *re && *re != ')'; re++) {
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switch (*re) {
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case '\\':;
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re++;
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if (!*re) goto syntax_error; // Trailing backslash
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char c = *re | 0x20;
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if (c == 'd' || c == 's' || c == 'w') {
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term = PC;
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EMIT(PC++, NAMEDCLASS);
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EMIT(PC++, *re);
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prog->len++;
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break;
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}
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if ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z'))
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goto unsupported_escape;
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default:
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term = PC;
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EMIT(PC++, CHAR);
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EMIT(PC++, *re);
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prog->len++;
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break;
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case '.':
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term = PC;
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EMIT(PC++, ANY);
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prog->len++;
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break;
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case '[':;
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int cnt;
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term = PC;
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re++;
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if (*re == '^') {
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EMIT(PC++, CLASSNOT);
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re++;
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} else {
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EMIT(PC++, CLASS);
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}
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PC++; // Skip "# of pairs" byte
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prog->len++;
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for (cnt = 0; *re != ']'; re++, cnt++) {
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if (!*re) goto syntax_error;
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if (*re == '\\') {
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re++;
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if (!*re) goto syntax_error;
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if (*re != '\\' && *re != ']')
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goto unsupported_escape;
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}
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EMIT(PC++, *re);
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if (re[1] == '-' && re[2] != ']')
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re += 2;
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EMIT(PC++, *re);
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}
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EMIT(term + 1, cnt);
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break;
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case '(':;
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term = PC;
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int sub;
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int capture = 1;
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re++;
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if (*re == '?') {
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re++;
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if (*re == ':') {
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capture = 0;
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re++;
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} else {
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*re_loc = re;
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return RE_UNSUPPORTED_SYNTAX;
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}
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}
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if (capture) {
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sub = ++prog->sub;
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EMIT(PC++, SAVE);
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EMIT(PC++, 2 * sub);
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prog->len++;
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}
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int res = _compilecode(&re, prog, sizecode);
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*re_loc = re;
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if (res < 0) return res;
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if (*re != ')') return RE_SYNTAX_ERROR;
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if (capture) {
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EMIT(PC++, SAVE);
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EMIT(PC++, 2 * sub + 1);
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prog->len++;
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}
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break;
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case '{':;
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int maxcnt = 0, mincnt = 0,
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i = 0, icnt = 1, size, split;
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re++;
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while (isdigit((unsigned char) *re))
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mincnt = mincnt * 10 + *re++ - '0';
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if (*re == ',') {
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re++;
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if (*re == '}')
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maxcnt = 256;
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while (isdigit((unsigned char) *re))
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maxcnt = maxcnt * 10 + *re++ - '0';
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} else
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maxcnt = mincnt;
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for (size = PC - term; i < mincnt-1; i++) {
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if (code)
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memcpy(&code[PC], &code[term], size*sizeof(int));
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PC += size;
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}
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split = *(re+1) == '[' ? RSPLIT : SPLIT;
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for (i = maxcnt-mincnt; i > 0; i--)
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{
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EMIT(PC++, split);
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EMIT(PC++, REL(PC, PC+((size+2)*i)));
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if (code)
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memcpy(&code[PC], &code[term], size*sizeof(int));
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PC += size;
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}
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if (code) {
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for (i = 0; i < size; i++)
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switch (code[term]) {
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case CLASS:
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case CLASSNOT:
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case NAMEDCLASS:
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case JMP:
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case SPLIT:
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case RSPLIT:
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case SAVE:
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case CHAR:
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icnt++;
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}
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}
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prog->len += maxcnt * icnt;
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break;
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case '?':
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if (PC == term) goto syntax_error; // nothing to repeat
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INSERT_CODE(term, 2, PC);
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if (re[1] == '?') {
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EMIT(term, RSPLIT);
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re++;
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} else {
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EMIT(term, SPLIT);
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}
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EMIT(term + 1, REL(term, PC));
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prog->len++;
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term = PC;
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break;
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case '*':
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if (PC == term) goto syntax_error; // nothing to repeat
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INSERT_CODE(term, 2, PC);
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EMIT(PC, JMP);
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EMIT(PC + 1, REL(PC, term));
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PC += 2;
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if (re[1] == '?') {
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EMIT(term, RSPLIT);
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re++;
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} else {
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EMIT(term, SPLIT);
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}
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EMIT(term + 1, REL(term, PC));
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prog->len += 2;
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term = PC;
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break;
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case '+':
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if (PC == term) goto syntax_error; // nothing to repeat
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if (re[1] == '?') {
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EMIT(PC, SPLIT);
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re++;
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} else {
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EMIT(PC, RSPLIT);
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}
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EMIT(PC + 1, REL(PC, term));
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PC += 2;
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prog->len++;
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term = PC;
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break;
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case '|':
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if (alt_label) {
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EMIT(alt_label, REL(alt_label, PC) + 1);
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}
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INSERT_CODE(start, 2, PC);
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EMIT(PC++, JMP);
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alt_label = PC++;
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EMIT(start, SPLIT);
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EMIT(start + 1, REL(start, PC));
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prog->len += 2;
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term = PC;
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break;
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case '^':
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EMIT(PC++, BOL);
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prog->len++;
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term = PC;
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break;
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case '$':
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EMIT(PC++, EOL);
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prog->len++;
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term = PC;
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break;
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}
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}
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if (alt_label) {
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EMIT(alt_label, REL(alt_label, PC) + 1);
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}
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*re_loc = re;
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return RE_SUCCESS;
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syntax_error:
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*re_loc = re;
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return RE_SYNTAX_ERROR;
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unsupported_escape:
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*re_loc = re;
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return RE_UNSUPPORTED_ESCAPE;
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}
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int re_sizecode(const char *re)
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{
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rcode dummyprog;
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// SAVE 0, SAVE 1, MATCH; more bytes for "search" (vs "match") prefix code
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dummyprog.unilen = 10;
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int res = _compilecode(&re, &dummyprog, /*sizecode*/1);
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if (res < 0) return res;
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// If unparsed chars left
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if (*re) return RE_SYNTAX_ERROR;
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return dummyprog.unilen;
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}
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int re_comp(rcode *prog, const char *re, int anchored)
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{
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prog->len = 0;
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prog->unilen = 0;
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prog->sub = 0;
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// Add code to implement non-anchored operation ("search").
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// For anchored operation ("match"), this code will be just skipped.
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// TODO: Implement search in much more efficient manner
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if (!anchored) {
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prog->insts[prog->unilen++] = RSPLIT;
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prog->insts[prog->unilen++] = 3;
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prog->insts[prog->unilen++] = ANY;
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prog->insts[prog->unilen++] = JMP;
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prog->insts[prog->unilen++] = -5;
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prog->insts[prog->unilen++] = SAVE;
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prog->insts[prog->unilen++] = 0;
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prog->len += 4;
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}
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int res = _compilecode(&re, prog, /*sizecode*/0);
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if (res < 0) return res;
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// If unparsed chars left
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if (*re) return RE_SYNTAX_ERROR;
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prog->insts[prog->unilen++] = SAVE;
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prog->insts[prog->unilen++] = 1;
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prog->insts[prog->unilen++] = MATCH;
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prog->len += 2;
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return RE_SUCCESS;
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}
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static void addthread(const int *pbeg, int *plist, int gen, rthreadlist *l,
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int *pc, rsub *sub, const char *beg, const char *sp)
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{
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int off;
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rec:
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if(plist[pc - pbeg] == gen) {
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decref(sub);
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return; // already on list
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}
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plist[pc - pbeg] = gen;
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switch(*pc) {
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default:
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l->t[l->n].sub = sub;
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l->t[l->n++].pc = pc;
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break;
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case JMP:
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off = pc[1];
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pc += 2 + off;
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goto rec;
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case SPLIT:
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off = pc[1];
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sub->ref++;
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addthread(pbeg, plist, gen, l, pc+2, sub, beg, sp);
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pc += 2 + off;
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goto rec;
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case RSPLIT:
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off = pc[1];
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pc += 2;
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sub->ref++;
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addthread(pbeg, plist, gen, l, pc + off, sub, beg, sp);
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goto rec;
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case SAVE:
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off = pc[1];
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pc += 2;
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sub = update(sub, off, sp);
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goto rec;
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case BOL:
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if(sp == beg)
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{ pc++; goto rec; }
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break;
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case EOL:
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if(!*sp)
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{ pc++; goto rec; }
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break;
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}
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}
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int re_pikevm(rcode *prog, const char *s, const char **subp, int nsubp)
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{
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int i, gen, *pc;
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const char *sp;
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int plist[prog->unilen];
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rsub *sub, *matched = NULL;
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rthreadlist _clist[1+prog->len];
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rthreadlist _nlist[1+prog->len];
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rthreadlist *clist = _clist, *nlist = _nlist, *tmp;
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memset(plist, 0, prog->unilen*sizeof(plist[0]));
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memset(clist, 0, (1+prog->len)*sizeof(rthread));
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memset(nlist, 0, (1+prog->len)*sizeof(rthread));
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subidx = 0;
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freesub = NULL;
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for(i=0; i<nsubp; i++)
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subp[i] = NULL;
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sub = newsub(nsubp);
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for(i=0; i<nsubp; i++)
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sub->sub[i] = NULL;
|
|
|
|
gen = 1;
|
|
addthread(prog->insts, plist, gen, clist, prog->insts, sub, s, s);
|
|
for(sp=s;; sp++) {
|
|
if(clist->n == 0)
|
|
break;
|
|
gen++;
|
|
for(i=0; i<clist->n; i++) {
|
|
pc = clist->t[i].pc;
|
|
sub = clist->t[i].sub;
|
|
if (inst_is_consumer(*pc) && !*sp) {
|
|
// If we need to match a character, but there's none left,
|
|
// it's fail (we don't schedule current thread for continuation)
|
|
decref(sub);
|
|
continue;
|
|
}
|
|
switch(*pc++) {
|
|
case CHAR:
|
|
if(*sp != *pc++) {
|
|
decref(sub);
|
|
break;
|
|
}
|
|
case ANY:
|
|
addthread:
|
|
addthread(prog->insts, plist, gen, nlist, pc, sub, s, sp+1);
|
|
break;
|
|
case CLASS:
|
|
case CLASSNOT:
|
|
if (!re_classmatch(pc, sp)) {
|
|
decref(sub);
|
|
break;
|
|
}
|
|
pc += *pc * 2 + 1;
|
|
goto addthread;
|
|
case NAMEDCLASS:
|
|
if (!re_namedclassmatch(pc, sp)) {
|
|
decref(sub);
|
|
break;
|
|
}
|
|
pc++;
|
|
goto addthread;
|
|
case MATCH:
|
|
if(matched)
|
|
decref(matched);
|
|
matched = sub;
|
|
for(i++; i < clist->n; i++)
|
|
decref(clist->t[i].sub);
|
|
goto BreakFor;
|
|
}
|
|
}
|
|
BreakFor:
|
|
tmp = clist;
|
|
clist = nlist;
|
|
nlist = tmp;
|
|
nlist->n = 0;
|
|
}
|
|
if(matched) {
|
|
for(i=0; i<nsubp; i++)
|
|
subp[i] = matched->sub[i];
|
|
decref(matched);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
if (argc < 2) {
|
|
printf("usage: <regex> <str...> <str...> ...\n");
|
|
return 0;
|
|
}
|
|
int sz = re_sizecode(argv[1]) * sizeof(int);
|
|
printf("Precalculated size: %d\n", sz);
|
|
char code[sizeof(rcode)+sz];
|
|
rcode *_code = (rcode*)&code;
|
|
if (re_comp(_code, argv[1], 0))
|
|
re_fatal("Error in re_comp");
|
|
re_dumpcode(_code);
|
|
if (argc > 2) {
|
|
int sub_els = (_code->sub + 1) * 2;
|
|
const char *sub[sub_els];
|
|
for (int i = 2; i < argc; i++) {
|
|
printf("sub depth %d\n", subidx);
|
|
if(!re_pikevm(_code, argv[i], sub, sub_els))
|
|
{ printf("-nomatch-\n"); continue; }
|
|
for(int k=sub_els; k>0; k--)
|
|
if(sub[k-1])
|
|
break;
|
|
for(int l=0; l<sub_els; l+=2) {
|
|
printf("(");
|
|
if(sub[l] == NULL)
|
|
printf("?");
|
|
else
|
|
printf("%d", (int)(sub[l] - argv[i]));
|
|
printf(",");
|
|
if(sub[l+1] == NULL)
|
|
printf("?");
|
|
else
|
|
printf("%d", (int)(sub[l+1] - argv[i]));
|
|
printf(")");
|
|
}
|
|
printf("\n");
|
|
}
|
|
|
|
}
|
|
return 0;
|
|
}
|