freebsd-src/contrib/less/pattern.c
Xin LI d713e0891f MFV: less v632.
MFC after:	2 weeks
2023-05-01 20:43:57 -07:00

492 lines
10 KiB
C

/*
* Copyright (C) 1984-2023 Mark Nudelman
*
* You may distribute under the terms of either the GNU General Public
* License or the Less License, as specified in the README file.
*
* For more information, see the README file.
*/
/*
* Routines to do pattern matching.
*/
#include "less.h"
extern int caseless;
extern int is_caseless;
extern int utf_mode;
/*
* Compile a search pattern, for future use by match_pattern.
*/
static int compile_pattern2(char *pattern, int search_type, PATTERN_TYPE *comp_pattern, int show_error)
{
if (search_type & SRCH_NO_REGEX)
return (0);
{
#if HAVE_GNU_REGEX
struct re_pattern_buffer *comp = (struct re_pattern_buffer *)
ecalloc(1, sizeof(struct re_pattern_buffer));
re_set_syntax(RE_SYNTAX_POSIX_EXTENDED);
if (re_compile_pattern(pattern, strlen(pattern), comp))
{
free(comp);
if (show_error)
error("Invalid pattern", NULL_PARG);
return (-1);
}
if (*comp_pattern != NULL)
{
regfree(*comp_pattern);
free(*comp_pattern);
}
*comp_pattern = comp;
#endif
#if HAVE_POSIX_REGCOMP
regex_t *comp = (regex_t *) ecalloc(1, sizeof(regex_t));
if (regcomp(comp, pattern, REGCOMP_FLAG | (is_caseless ? REG_ICASE : 0)))
{
free(comp);
if (show_error)
error("Invalid pattern", NULL_PARG);
return (-1);
}
if (*comp_pattern != NULL)
{
regfree(*comp_pattern);
free(*comp_pattern);
}
*comp_pattern = comp;
#endif
#if HAVE_PCRE
constant char *errstring;
int erroffset;
PARG parg;
pcre *comp = pcre_compile(pattern,
((utf_mode) ? PCRE_UTF8 | PCRE_NO_UTF8_CHECK : 0) |
(is_caseless ? PCRE_CASELESS : 0),
&errstring, &erroffset, NULL);
if (comp == NULL)
{
parg.p_string = (char *) errstring;
if (show_error)
error("%s", &parg);
return (-1);
}
*comp_pattern = comp;
#endif
#if HAVE_PCRE2
int errcode;
PCRE2_SIZE erroffset;
PARG parg;
pcre2_code *comp = pcre2_compile((PCRE2_SPTR)pattern, strlen(pattern),
(is_caseless ? PCRE2_CASELESS : 0),
&errcode, &erroffset, NULL);
if (comp == NULL)
{
if (show_error)
{
char msg[160];
pcre2_get_error_message(errcode, (PCRE2_UCHAR*)msg, sizeof(msg));
parg.p_string = msg;
error("%s", &parg);
}
return (-1);
}
*comp_pattern = comp;
#endif
#if HAVE_RE_COMP
PARG parg;
if ((parg.p_string = re_comp(pattern)) != NULL)
{
if (show_error)
error("%s", &parg);
return (-1);
}
*comp_pattern = 1;
#endif
#if HAVE_REGCMP
char *comp;
if ((comp = regcmp(pattern, 0)) == NULL)
{
if (show_error)
error("Invalid pattern", NULL_PARG);
return (-1);
}
if (comp_pattern != NULL)
free(*comp_pattern);
*comp_pattern = comp;
#endif
#if HAVE_V8_REGCOMP
struct regexp *comp;
reg_show_error = show_error;
comp = regcomp(pattern);
reg_show_error = 1;
if (comp == NULL)
{
/*
* regcomp has already printed an error message
* via regerror().
*/
return (-1);
}
if (*comp_pattern != NULL)
free(*comp_pattern);
*comp_pattern = comp;
#endif
}
return (0);
}
/*
* Like compile_pattern2, but convert the pattern to lowercase if necessary.
*/
public int compile_pattern(char *pattern, int search_type, int show_error, PATTERN_TYPE *comp_pattern)
{
char *cvt_pattern;
int result;
if (caseless != OPT_ONPLUS || (re_handles_caseless && !(search_type & SRCH_NO_REGEX)))
cvt_pattern = pattern;
else
{
cvt_pattern = (char*) ecalloc(1, cvt_length(strlen(pattern), CVT_TO_LC));
cvt_text(cvt_pattern, pattern, (int *)NULL, (int *)NULL, CVT_TO_LC);
}
result = compile_pattern2(cvt_pattern, search_type, comp_pattern, show_error);
if (cvt_pattern != pattern)
free(cvt_pattern);
return (result);
}
/*
* Forget that we have a compiled pattern.
*/
public void uncompile_pattern(PATTERN_TYPE *pattern)
{
#if HAVE_GNU_REGEX
if (*pattern != NULL)
{
regfree(*pattern);
free(*pattern);
}
*pattern = NULL;
#endif
#if HAVE_POSIX_REGCOMP
if (*pattern != NULL)
{
regfree(*pattern);
free(*pattern);
}
*pattern = NULL;
#endif
#if HAVE_PCRE
if (*pattern != NULL)
pcre_free(*pattern);
*pattern = NULL;
#endif
#if HAVE_PCRE2
if (*pattern != NULL)
pcre2_code_free(*pattern);
*pattern = NULL;
#endif
#if HAVE_RE_COMP
*pattern = 0;
#endif
#if HAVE_REGCMP
if (*pattern != NULL)
free(*pattern);
*pattern = NULL;
#endif
#if HAVE_V8_REGCOMP
if (*pattern != NULL)
free(*pattern);
*pattern = NULL;
#endif
}
#if 0
/*
* Can a pattern be successfully compiled?
*/
public int valid_pattern(char *pattern)
{
PATTERN_TYPE comp_pattern;
int result;
SET_NULL_PATTERN(comp_pattern);
result = compile_pattern2(pattern, 0, &comp_pattern, 0);
if (result != 0)
return (0);
uncompile_pattern(&comp_pattern);
return (1);
}
#endif
/*
* Is a compiled pattern null?
*/
public int is_null_pattern(PATTERN_TYPE pattern)
{
#if HAVE_GNU_REGEX
return (pattern == NULL);
#endif
#if HAVE_POSIX_REGCOMP
return (pattern == NULL);
#endif
#if HAVE_PCRE
return (pattern == NULL);
#endif
#if HAVE_PCRE2
return (pattern == NULL);
#endif
#if HAVE_RE_COMP
return (pattern == 0);
#endif
#if HAVE_REGCMP
return (pattern == NULL);
#endif
#if HAVE_V8_REGCOMP
return (pattern == NULL);
#endif
#if NO_REGEX
return (pattern == NULL);
#endif
}
/*
* Simple pattern matching function.
* It supports no metacharacters like *, etc.
*/
static int match(char *pattern, int pattern_len, char *buf, int buf_len, char ***sp, char ***ep, int nsubs)
{
char *pp, *lp;
char *pattern_end = pattern + pattern_len;
char *buf_end = buf + buf_len;
for ( ; buf < buf_end; buf++)
{
for (pp = pattern, lp = buf; ; pp++, lp++)
{
char cp = *pp;
char cl = *lp;
if (caseless == OPT_ONPLUS && ASCII_IS_UPPER(cp))
cp = ASCII_TO_LOWER(cp);
if (cp != cl)
break;
if (pp == pattern_end || lp == buf_end)
break;
}
if (pp == pattern_end)
{
*(*sp)++ = buf;
*(*ep)++ = lp;
return (1);
}
}
**sp = **ep = NULL;
return (0);
}
/*
* Perform a pattern match with the previously compiled pattern.
* Set sp[0] and ep[0] to the start and end of the matched string.
* Set sp[i] and ep[i] to the start and end of the i-th matched subpattern.
* Subpatterns are defined by parentheses in the regex language.
*/
static int match_pattern1(PATTERN_TYPE pattern, char *tpattern, char *line, int line_len, char **sp, char **ep, int nsp, int notbol, int search_type)
{
int matched;
#if NO_REGEX
search_type |= SRCH_NO_REGEX;
#endif
if (search_type & SRCH_NO_REGEX)
matched = match(tpattern, strlen(tpattern), line, line_len, &sp, &ep, nsp);
else
{
#if HAVE_GNU_REGEX
{
struct re_registers search_regs;
pattern->not_bol = notbol;
pattern->regs_allocated = REGS_UNALLOCATED;
matched = re_search(pattern, line, line_len, 0, line_len, &search_regs) >= 0;
if (matched)
{
*sp++ = line + search_regs.start[0];
*ep++ = line + search_regs.end[0];
}
}
#endif
#if HAVE_POSIX_REGCOMP
{
#define RM_COUNT (NUM_SEARCH_COLORS+2)
regmatch_t rm[RM_COUNT];
int flags = (notbol) ? REG_NOTBOL : 0;
#ifdef REG_STARTEND
flags |= REG_STARTEND;
rm[0].rm_so = 0;
rm[0].rm_eo = line_len;
#endif
matched = !regexec(pattern, line, RM_COUNT, rm, flags);
if (matched)
{
int i;
int ecount;
for (ecount = RM_COUNT; ecount > 0; ecount--)
if (rm[ecount-1].rm_so >= 0)
break;
if (ecount >= nsp)
ecount = nsp-1;
for (i = 0; i < ecount; i++)
{
if (rm[i].rm_so < 0)
{
*sp++ = *ep++ = line;
} else
{
#ifndef __WATCOMC__
*sp++ = line + rm[i].rm_so;
*ep++ = line + rm[i].rm_eo;
#else
*sp++ = rm[i].rm_sp;
*ep++ = rm[i].rm_ep;
#endif
}
}
}
}
#endif
#if HAVE_PCRE
{
#define OVECTOR_COUNT ((3*NUM_SEARCH_COLORS)+3)
int ovector[OVECTOR_COUNT];
int flags = (notbol) ? PCRE_NOTBOL : 0;
int i;
int ecount;
int mcount = pcre_exec(pattern, NULL, line, line_len,
0, flags, ovector, OVECTOR_COUNT);
matched = (mcount > 0);
ecount = nsp-1;
if (ecount > mcount) ecount = mcount;
for (i = 0; i < ecount*2; )
{
if (ovector[i] < 0 || ovector[i+1] < 0)
{
*sp++ = *ep++ = line;
i += 2;
} else
{
*sp++ = line + ovector[i++];
*ep++ = line + ovector[i++];
}
}
}
#endif
#if HAVE_PCRE2
{
int flags = (notbol) ? PCRE2_NOTBOL : 0;
pcre2_match_data *md = pcre2_match_data_create(nsp-1, NULL);
int mcount = pcre2_match(pattern, (PCRE2_SPTR)line, line_len,
0, flags, md, NULL);
matched = (mcount > 0);
if (matched)
{
PCRE2_SIZE *ovector = pcre2_get_ovector_pointer(md);
int i;
int ecount = nsp-1;
if (ecount > mcount) ecount = mcount;
for (i = 0; i < ecount*2; )
{
if (ovector[i] < 0 || ovector[i+1] < 0)
{
*sp++ = *ep++ = line;
i += 2;
} else
{
*sp++ = line + ovector[i++];
*ep++ = line + ovector[i++];
}
}
}
pcre2_match_data_free(md);
}
#endif
#if HAVE_RE_COMP
matched = (re_exec(line) == 1);
/*
* re_exec doesn't seem to provide a way to get the matched string.
*/
#endif
#if HAVE_REGCMP
matched = ((*ep++ = regex(pattern, line)) != NULL);
if (matched)
*sp++ = __loc1;
#endif
#if HAVE_V8_REGCOMP
#if HAVE_REGEXEC2
matched = regexec2(pattern, line, notbol);
#else
matched = regexec(pattern, line);
#endif
if (matched)
{
*sp++ = pattern->startp[0];
*ep++ = pattern->endp[0];
}
#endif
}
*sp = *ep = NULL;
matched = (!(search_type & SRCH_NO_MATCH) && matched) ||
((search_type & SRCH_NO_MATCH) && !matched);
return (matched);
}
public int match_pattern(PATTERN_TYPE pattern, char *tpattern, char *line, int line_len, char **sp, char **ep, int nsp, int notbol, int search_type)
{
int matched = match_pattern1(pattern, tpattern, line, line_len, sp, ep, nsp, notbol, search_type);
int i;
for (i = 1; i <= NUM_SEARCH_COLORS; i++)
{
if ((search_type & SRCH_SUBSEARCH(i)) && ep[i] == sp[i])
matched = 0;
}
return matched;
}
/*
* Return the name of the pattern matching library.
*/
public char * pattern_lib_name(void)
{
#if HAVE_GNU_REGEX
return ("GNU");
#else
#if HAVE_POSIX_REGCOMP
return ("POSIX");
#else
#if HAVE_PCRE2
return ("PCRE2");
#else
#if HAVE_PCRE
return ("PCRE");
#else
#if HAVE_RE_COMP
return ("BSD");
#else
#if HAVE_REGCMP
return ("V8");
#else
#if HAVE_V8_REGCOMP
return ("Spencer V8");
#else
return ("no");
#endif
#endif
#endif
#endif
#endif
#endif
#endif
}