csope/source/egrep.y
2023-09-26 09:29:23 +02:00

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%{
/*===========================================================================
Copyright (c) 1998-2000, The Santa Cruz Operation
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
*Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
*Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
*Neither name of The Santa Cruz Operation nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT falseT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT falseT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
=========================================================================*/
/*
* egrep -- fine lines containing a regular expression
*/
%}
%token CHAR DOT CCL NCCL OR CAT STAR PLUS QUEST
%left OR
%left CHAR DOT CCL NCCL '('
%left CAT
%left STAR PLUS QUEST
%{
#include "global.h"
#include <ctype.h>
#include <stdio.h>
#include <setjmp.h> /* jmp_buf */
#define nextch() (*input++)
#define MAXLIN 350
#define MAXPOS 4000
#define NCHARS 256
#define NSTATES 128
#define FINAL -1
static char gotofn[NSTATES][NCHARS];
static int state[NSTATES];
static char out[NSTATES];
static unsigned int line;
static int name[MAXLIN];
static unsigned int left[MAXLIN];
static unsigned int right[MAXLIN];
static unsigned int parent[MAXLIN];
static int foll[MAXLIN];
static int positions[MAXPOS];
static char chars[MAXLIN];
static int nxtpos;
static int nxtchar;
static int tmpstat[MAXLIN];
static int initstat[MAXLIN];
static int xstate;
static int count;
static int icount;
static char *input;
static long lnum;
static int iflag;
static jmp_buf env; /* setjmp/longjmp buffer */
static char *message; /* error message */
/* Internal prototypes: */
static void cfoll(int v);
static void cgotofn(void);
static int cstate(int v);
static int member(int symb, int set, int torf);
static int notin(int n);
static void synerror(void);
static void overflo(void);
static void add(int *array, int n);
static void follow(unsigned int v);
static int unary(int x, int d);
static int node(int x, int l, int r);
static unsigned int cclenter(int x);
static unsigned int enter(int x);
static int yylex(void);
static int yyerror(char *);
%}
%%
s: t
{ unary(FINAL, $1);
line--;
}
;
t: b r
{ $$ = node(CAT, $1, $2); }
| OR b r OR
{ $$ = node(CAT, $2, $3); }
| OR b r
{ $$ = node(CAT, $2, $3); }
| b r OR
{ $$ = node(CAT, $1, $2); }
;
b:
{ $$ = enter(DOT);
$$ = unary(STAR, $$); }
;
r: CHAR
{ $$ = enter($1); }
| DOT
{ $$ = enter(DOT); }
| CCL
{ $$ = cclenter(CCL); }
| NCCL
{ $$ = cclenter(NCCL); }
;
r: r OR r
{ $$ = node(OR, $1, $3); }
| r r %prec CAT
{ $$ = node(CAT, $1, $2); }
| r STAR
{ $$ = unary(STAR, $1); }
| r PLUS
{ $$ = unary(PLUS, $1); }
| r QUEST
{ $$ = unary(QUEST, $1); }
| '(' r ')'
{ $$ = $2; }
| error
;
%%
static int
yyerror(char *s)
{
message = s;
longjmp(env, 1);
return 1; /* silence a warning */
}
static int
yylex(void)
{
int cclcnt, x;
char c, d;
switch(c = nextch()) {
case '|':
case '\n':
return (OR);
case '*':
return (STAR);
case '+':
return (PLUS);
case '?':
return (QUEST);
case '(':
case ')':
return (c);
case '.':
return (DOT);
case '\0':
return (0);
case '[':
x = CCL;
cclcnt = 0;
count = nxtchar++;
if ((c = nextch()) == '^') {
x = NCCL;
c = nextch();
}
do {
if (c == '\0')
synerror();
if ( (c == '-')
&& (cclcnt > 0)
&& (chars[nxtchar-1] != 0)
) {
if ((d = nextch()) != 0) {
c = chars[nxtchar-1];
while ((unsigned int)c < (unsigned int)d) {
if (nxtchar >= MAXLIN)
overflo();
chars[nxtchar++] = ++c;
cclcnt++;
}
continue;
} /* if() */
} /* if() */
if (nxtchar >= MAXLIN)
overflo();
chars[nxtchar++] = c;
cclcnt++;
} while ((c = nextch()) != ']');
chars[count] = cclcnt;
return (x);
case '\\':
if ((c = nextch()) == '\0')
synerror();
yylval = c;
return (CHAR);
case '$':
case '^':
c = '\n';
yylval = c;
return (CHAR);
default:
yylval = c;
return (CHAR);
}
}
static void
synerror(void)
{
yyerror("Syntax error");
}
static unsigned int
enter(int x)
{
if(line >= MAXLIN)
overflo();
name[line] = x;
left[line] = 0;
right[line] = 0;
return(line++);
}
static unsigned int
cclenter(int x)
{
unsigned int linno;
linno = enter(x);
right[linno] = count;
return (linno);
}
static int
node(int x, int l, int r)
{
if(line >= MAXLIN)
overflo();
name[line] = x;
left[line] = l;
right[line] = r;
parent[l] = line;
parent[r] = line;
return(line++);
}
static int
unary(int x, int d)
{
if(line >= MAXLIN)
overflo();
name[line] = x;
left[line] = d;
right[line] = 0;
parent[d] = line;
return(line++);
}
static void
overflo(void)
{
yyerror("internal table overflow");
}
static void
cfoll(int v)
{
unsigned int i;
if (left[v] == 0) {
count = 0;
for (i = 1; i <= line; i++)
tmpstat[i] = 0;
follow(v);
add(foll, v);
} else if (right[v] == 0)
cfoll(left[v]);
else {
cfoll(left[v]);
cfoll(right[v]);
}
}
static void
cgotofn(void)
{
unsigned int i, n, s;
int c, k;
char symbol[NCHARS];
unsigned int j, l, pc, pos;
unsigned int nc;
int curpos;
unsigned int num, number, newpos;
count = 0;
for (n=3; n<=line; n++)
tmpstat[n] = 0;
if (cstate(line-1)==0) {
tmpstat[line] = 1;
count++;
out[0] = 1;
}
for (n=3; n<=line; n++)
initstat[n] = tmpstat[n];
count--; /*leave out position 1 */
icount = count;
tmpstat[1] = 0;
add(state, 0);
n = 0;
for (s = 0; s <= n; s++) {
if (out[s] == 1)
continue;
for (i = 0; i < NCHARS; i++)
symbol[i] = 0;
num = positions[state[s]];
count = icount;
for (i = 3; i <= line; i++)
tmpstat[i] = initstat[i];
pos = state[s] + 1;
for (i = 0; i < num; i++) {
curpos = positions[pos];
if ((c = name[curpos]) >= 0) {
if (c < NCHARS) {
symbol[c] = 1;
} else if (c == DOT) {
for (k = 0; k < NCHARS; k++)
if (k != '\n')
symbol[k] = 1;
} else if (c == CCL) {
nc = chars[right[curpos]];
pc = right[curpos] + 1;
for (j = 0; j < nc; j++)
symbol[(unsigned char)chars[pc++]] = 1;
} else if (c == NCCL) {
nc = chars[right[curpos]];
for (j = 0; j < NCHARS; j++) {
pc = right[curpos] + 1;
for (l = 0; l < nc; l++)
if (j==(unsigned char)chars[pc++])
goto cont;
if (j != '\n')
symbol[j] = 1;
cont:
;
}
}
}
pos++;
} /* for (i) */
for (c=0; c<NCHARS; c++) {
if (symbol[c] == 1) {
/* nextstate(s,c) */
count = icount;
for (i=3; i <= line; i++)
tmpstat[i] = initstat[i];
pos = state[s] + 1;
for (i=0; i<num; i++) {
curpos = positions[pos];
if ((k = name[curpos]) >= 0)
if ((k == c)
|| (k == DOT)
|| (k == CCL && member(c, right[curpos], 1))
|| (k == NCCL && member(c, right[curpos], 0))
) {
number = positions[foll[curpos]];
newpos = foll[curpos] + 1;
for (j = 0; j < number; j++) {
if (tmpstat[positions[newpos]] != 1) {
tmpstat[positions[newpos]] = 1;
count++;
}
newpos++;
}
}
pos++;
} /* end nextstate */
if (notin(n)) {
if (n >= NSTATES)
overflo();
add(state, ++n);
if (tmpstat[line] == 1)
out[n] = 1;
gotofn[s][c] = n;
} else {
gotofn[s][c] = xstate;
}
} /* if (symbol) */
} /* for(c) */
} /* for(s) */
}
static int
cstate(int v)
{
int b;
if (left[v] == 0) {
if (tmpstat[v] != 1) {
tmpstat[v] = 1;
count++;
}
return(1);
}
else if (right[v] == 0) {
if (cstate(left[v]) == 0) return (0);
else if (name[v] == PLUS) return (1);
else return (0);
}
else if (name[v] == CAT) {
if (cstate(left[v]) == 0 && cstate(right[v]) == 0) return (0);
else return (1);
}
else { /* name[v] == OR */
b = cstate(right[v]);
if (cstate(left[v]) == 0 || b == 0) return (0);
else return (1);
}
}
static int
member(int symb, int set, int torf)
{
unsigned int i, num, pos;
num = chars[set];
pos = set + 1;
for (i = 0; i < num; i++)
if (symb == (unsigned char)(chars[pos++]))
return (torf);
return (!torf);
}
static int
notin(int n)
{
int i, j, pos;
for (i=0; i<=n; i++) {
if (positions[state[i]] == count) {
pos = state[i] + 1;
for (j=0; j < count; j++)
if (tmpstat[positions[pos++]] != 1) goto nxt;
xstate = i;
return (0);
}
nxt: ;
}
return (1);
}
static void
add(int *array, int n)
{
unsigned int i;
if (nxtpos + count > MAXPOS)
overflo();
array[n] = nxtpos;
positions[nxtpos++] = count;
for (i=3; i <= line; i++) {
if (tmpstat[i] == 1) {
positions[nxtpos++] = i;
}
}
}
static void
follow(unsigned int v)
{
unsigned int p;
if (v == line)
return;
p = parent[v];
switch(name[p]) {
case STAR:
case PLUS: cstate(v);
follow(p);
return;
case OR:
case QUEST: follow(p);
return;
case CAT:
if (v == left[p]) {
if (cstate(right[p]) == 0) {
follow(p);
return;
}
} else
follow(p);
return;
case FINAL:
if (tmpstat[line] != 1) {
tmpstat[line] = 1;
count++;
}
return;
}
}
char *
egrepinit(const char *egreppat)
{
/* initialize the global data */
memset(gotofn, 0, sizeof(gotofn));
memset(state, 0, sizeof(state));
memset(out, 0, sizeof(out));
line = 1;
memset(name, 0, sizeof(name));
memset(left, 0, sizeof(left));
memset(right, 0, sizeof(right));
memset(parent, 0, sizeof(parent));
memset(foll, 0, sizeof(foll));
memset(positions, 0, sizeof(positions));
memset(chars, 0, sizeof(chars));
nxtpos = 0;
nxtchar = 0;
memset(tmpstat, 0, sizeof(tmpstat));
memset(initstat, 0, sizeof(initstat));
xstate = 0;
count = 0;
icount = 0;
input = egreppat;
message = NULL;
if (setjmp(env) == 0) {
yyparse();
cfoll(line-1);
cgotofn();
}
return(message);
}
static char buf[2 * BUFSIZ];
static const char *buf_end = buf + (sizeof(buf) / sizeof(*buf));
static size_t read_next_chunk(char **p, FILE *fptr)
{
if (*p <= (buf + BUFSIZ)) {
/* bwlow the middle, so enough space left for one entire BUFSIZ */
return fread(*p, sizeof(**p), BUFSIZ, fptr);
} else if (*p == buf_end) {
/* exactly at end ... wrap around and use lower half */
*p = buf;
return fread(*p, sizeof(**p), BUFSIZ, fptr);
}
/* somewhere in second half, so do a limited read */
return fread(*p, sizeof(**p), buf_end - *p, fptr);
}
int
egrep(char *file, FILE *output, char *format)
{
char *p;
unsigned int cstat;
int ccount;
char *nlp;
unsigned int istat;
int in_line;
FILE *fptr;
if ((fptr = myfopen(file, "r")) == NULL)
return(-1);
lnum = 1;
p = buf;
nlp = p;
ccount = read_next_chunk(&p, fptr);
if (ccount <= 0) {
fclose(fptr);
return(0);
}
in_line = 1;
istat = cstat = (unsigned int) gotofn[0]['\n'];
if (out[cstat])
goto found;
for (;;) {
if (!iflag) {
/* all input chars made positive */
cstat = (unsigned int) gotofn[cstat][(unsigned char)*p];
} else {
/* for -i option*/
cstat = (unsigned int) gotofn[cstat][tolower((unsigned char)*p)];
}
if (out[cstat]) {
found:
for(;;) {
if (*p++ == '\n') {
in_line = 0;
succeed:
fprintf(output, format, file, lnum);
if (p <= nlp) {
while (nlp < buf_end)
putc(*nlp++, output);
nlp = buf;
}
while (nlp < p)
putc(*nlp++, output);
lnum++;
nlp = p;
if (out[cstat = istat] == 0)
goto brk2;
} /* if (p++ == \n) */
cfound:
if (--ccount <= 0) {
ccount = read_next_chunk(&p, fptr);
if (ccount <= 0) {
if (in_line) {
in_line = 0;
goto succeed;
}
fclose(fptr);
return(0);
}
} /* if(ccount <= 0) */
in_line = 1;
} /* for(ever) */
} /* if(out[cstat]) */
if (*p++ == '\n') {
in_line = 0;
lnum++;
nlp = p;
if (out[(cstat=istat)])
goto cfound;
}
brk2:
if (--ccount <= 0) {
ccount = read_next_chunk(&p, fptr);
if (ccount <= 0)
break;
}
in_line = 1;
}
fclose(fptr);
return(0);
}
void
egrepcaseless(int i)
{
iflag = i; /* simulate "egrep -i" */
}