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(trivial_regexp_p): New function.

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(search_buffer): Don't depend on internal format of re_pattern_buffer.
This commit is contained in:
Karl Heuer 1994-09-20 05:40:52 +00:00
parent 3fec4c1b34
commit b6d6a51cfb
1 changed files with 55 additions and 26 deletions
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81
src/search.c
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@ -592,6 +592,35 @@ search_command (string, bound, noerror, count, direction, RE)
return make_number (np);
}
static int
trivial_regexp_p (regexp)
Lisp_Object regexp;
{
int len = XSTRING (regexp)->size;
unsigned char *s = XSTRING (regexp)->data;
unsigned char c;
while (--len >= 0)
{
switch (*s++)
{
case '.': case '*': case '+': case '?': case '[': case '^': case '$':
return 0;
case '\\':
if (--len < 0)
return 0;
switch (*s++)
{
case '|': case '(': case ')': case '`': case '\'': case 'b':
case 'B': case '<': case '>': case 'w': case 'W': case 's':
case 'S': case '1': case '2': case '3': case '4': case '5':
case '6': case '7': case '8': case '9':
return 0;
}
}
}
return 1;
}
/* Search for the n'th occurrence of STRING in the current buffer,
starting at position POS and stopping at position LIM,
treating PAT as a literal string if RE is false or as
@ -636,32 +665,10 @@ search_buffer (string, pos, lim, n, RE, trt, inverse_trt)
if (n == 0)
return pos;
if (RE)
compile_pattern (string, &searchbuf, &search_regs, (char *) trt);
if (RE /* Here we detect whether the */
/* generality of an RE search is */
/* really needed. */
/* first item is "exact match" */
&& *(searchbuf.buffer) == (char) RE_EXACTN_VALUE
&& searchbuf.buffer[1] + 2 == searchbuf.used) /*first is ONLY item */
if (RE && !trivial_regexp_p (string))
{
RE = 0; /* can do straight (non RE) search */
pat = (base_pat = (unsigned char *) searchbuf.buffer + 2);
/* trt already applied */
len = searchbuf.used - 2;
}
else if (!RE)
{
pat = (unsigned char *) alloca (len);
compile_pattern (string, &searchbuf, &search_regs, (char *) trt);
for (i = len; i--;) /* Copy the pattern; apply trt */
*pat++ = (((int) trt) ? trt [*base_pat++] : *base_pat++);
pat -= len; base_pat = pat;
}
if (RE)
{
immediate_quit = 1; /* Quit immediately if user types ^G,
because letting this function finish
can take too long. */
@ -693,7 +700,9 @@ search_buffer (string, pos, lim, n, RE, trt, inverse_trt)
/* Don't allow match past current point */
pos - BEGV);
if (val == -2)
matcher_overflow ();
{
matcher_overflow ();
}
if (val >= 0)
{
j = BEGV;
@ -721,7 +730,9 @@ search_buffer (string, pos, lim, n, RE, trt, inverse_trt)
pos - BEGV, lim - pos, &search_regs,
lim - BEGV);
if (val == -2)
matcher_overflow ();
{
matcher_overflow ();
}
if (val >= 0)
{
j = BEGV;
@ -752,6 +763,24 @@ search_buffer (string, pos, lim, n, RE, trt, inverse_trt)
#else
BM_tab = (int *) alloca (0400 * sizeof (int));
#endif
{
unsigned char *patbuf = (unsigned char *) alloca (len);
pat = patbuf;
while (--len >= 0)
{
/* If we got here and the RE flag is set, it's because we're
dealing with a regexp known to be trivial, so the backslash
just quotes the next character. */
if (RE && *base_pat == '\\')
{
len--;
base_pat++;
}
*pat++ = (trt ? trt[*base_pat++] : *base_pat++);
}
len = pat - patbuf;
pat = base_pat = patbuf;
}
/* The general approach is that we are going to maintain that we know */
/* the first (closest to the present position, in whatever direction */
/* we're searching) character that could possibly be the last */