updated for version 7.3.1037
Problem: Look-behind matching is very slow on long lines.
Solution: Add a byte limit to how far back an attempt is made.
diff --git a/src/regexp.c b/src/regexp.c
index c7b25c2..f0b9325 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -701,6 +701,7 @@
# define CASEMBC(x)
#endif
static void reginsert __ARGS((int, char_u *));
+static void reginsert_nr __ARGS((int op, long val, char_u *opnd));
static void reginsert_limits __ARGS((int, long, long, char_u *));
static char_u *re_put_long __ARGS((char_u *pr, long_u val));
static int read_limits __ARGS((long *, long *));
@@ -1781,7 +1782,9 @@
case Magic('@'):
{
int lop = END;
+ int nr;
+ nr = getdecchrs();
switch (no_Magic(getchr()))
{
case '=': lop = MATCH; break; /* \@= */
@@ -1803,7 +1806,14 @@
*flagp |= HASLOOKBH;
}
regtail(ret, regnode(END)); /* operand ends */
- reginsert(lop, ret);
+ if (lop == BEHIND || lop == NOBEHIND)
+ {
+ if (nr < 0)
+ nr = 0; /* no limit is same as zero limit */
+ reginsert_nr(lop, nr, ret);
+ }
+ else
+ reginsert(lop, ret);
break;
}
@@ -2780,6 +2790,38 @@
/*
* Insert an operator in front of already-emitted operand.
+ * Add a number to the operator.
+ */
+ static void
+reginsert_nr(op, val, opnd)
+ int op;
+ long val;
+ char_u *opnd;
+{
+ char_u *src;
+ char_u *dst;
+ char_u *place;
+
+ if (regcode == JUST_CALC_SIZE)
+ {
+ regsize += 7;
+ return;
+ }
+ src = regcode;
+ regcode += 7;
+ dst = regcode;
+ while (src > opnd)
+ *--dst = *--src;
+
+ place = opnd; /* Op node, where operand used to be. */
+ *place++ = op;
+ *place++ = NUL;
+ *place++ = NUL;
+ place = re_put_long(place, (long_u)val);
+}
+
+/*
+ * Insert an operator in front of already-emitted operand.
* The operator has the given limit values as operands. Also set next pointer.
*
* Means relocating the operand.
@@ -3182,7 +3224,7 @@
}
/*
- * get and return the value of the decimal string immediately after the
+ * Get and return the value of the decimal string immediately after the
* current position. Return -1 for invalid. Consumes all digits.
*/
static int
@@ -3200,6 +3242,7 @@
nr *= 10;
nr += c - '0';
++regparse;
+ curchr = -1; /* no longer valid */
}
if (i == 0)
@@ -5432,7 +5475,7 @@
/* save the position after the found match for next */
reg_save(&(((regbehind_T *)rp) - 1)->save_after, &backpos);
- /* start looking for a match with operand at the current
+ /* Start looking for a match with operand at the current
* position. Go back one character until we find the
* result, hitting the start of the line or the previous
* line (for multi-line matching).
@@ -5444,7 +5487,7 @@
rp->rs_state = RS_BEHIND2;
reg_restore(&rp->rs_un.regsave, &backpos);
- scan = OPERAND(rp->rs_scan);
+ scan = OPERAND(rp->rs_scan) + 4;
}
break;
@@ -5472,9 +5515,12 @@
}
else
{
+ long limit;
+
/* No match or a match that doesn't end where we want it: Go
* back one character. May go to previous line once. */
no = OK;
+ limit = OPERAND_MIN(rp->rs_scan);
if (REG_MULTI)
{
if (rp->rs_un.regsave.rs_u.pos.col == 0)
@@ -5493,27 +5539,41 @@
}
}
else
+ {
#ifdef FEAT_MBYTE
- if (has_mbyte)
- rp->rs_un.regsave.rs_u.pos.col -=
- (*mb_head_off)(regline, regline
+ if (has_mbyte)
+ rp->rs_un.regsave.rs_u.pos.col -=
+ (*mb_head_off)(regline, regline
+ rp->rs_un.regsave.rs_u.pos.col - 1) + 1;
- else
+ else
#endif
- --rp->rs_un.regsave.rs_u.pos.col;
+ --rp->rs_un.regsave.rs_u.pos.col;
+ if (limit > 0
+ && ((rp->rs_un.regsave.rs_u.pos.lnum
+ < behind_pos.rs_u.pos.lnum
+ ? (colnr_T)STRLEN(regline)
+ : behind_pos.rs_u.pos.col)
+ - rp->rs_un.regsave.rs_u.pos.col > limit))
+ no = FAIL;
+ }
}
else
{
if (rp->rs_un.regsave.rs_u.ptr == regline)
no = FAIL;
else
- --rp->rs_un.regsave.rs_u.ptr;
+ {
+ mb_ptr_back(regline, rp->rs_un.regsave.rs_u.ptr);
+ if (limit > 0 && (long)(behind_pos.rs_u.ptr
+ - rp->rs_un.regsave.rs_u.ptr) > limit)
+ no = FAIL;
+ }
}
if (no == OK)
{
/* Advanced, prepare for finding match again. */
reg_restore(&rp->rs_un.regsave, &backpos);
- scan = OPERAND(rp->rs_scan);
+ scan = OPERAND(rp->rs_scan) + 4;
if (status == RA_MATCH)
{
/* We did match, so subexpr may have been changed,
@@ -7773,7 +7833,7 @@
#ifdef DEBUG
static char_u regname[][30] = {
"AUTOMATIC Regexp Engine",
- "BACKTACKING Regexp Engine",
+ "BACKTRACKING Regexp Engine",
"NFA Regexp Engine"
};
#endif