[k-takata/Onigmo] Remove code for backward BM search

The code has not been used for long.
(Oniguruma also removed this code.)

https://github.com/k-takata/Onigmo/commit/8796781fdd

3 files changed, 1 insertions, 76 deletions

diff --git a/include/ruby/onigmo.h b/include/ruby/onigmo.h
index f949219308..b9a21206de 100644
--- a/include/ruby/onigmo.h
+++ b/include/ruby/onigmo.h
@@ -790,7 +790,7 @@ typedef struct re_pattern_buffer {
   unsigned char *exact_end;
   unsigned char  map[ONIG_CHAR_TABLE_SIZE]; /* used as BM skip or char-map */
   int           *reserved1;
-  int           *int_map_backward;          /* BM skip for backward search */
+  int           *reserved2;
   OnigDistance   dmin;                      /* min-distance of exact or map */
   OnigDistance   dmax;                      /* max-distance of exact or map */
 
diff --git a/regcomp.c b/regcomp.c
index 3445fcaccb..6ad72bcbd0 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -5572,7 +5572,6 @@ onig_free_body(regex_t* reg)
   if (IS_NOT_NULL(reg)) {
     xfree(reg->p);
     xfree(reg->exact);
-    xfree(reg->int_map_backward);
     xfree(reg->repeat_range);
     onig_free(reg->chain);
 
@@ -5619,10 +5618,6 @@ onig_reg_copy(regex_t** nreg, regex_t* oreg)
       (reg)->exact_end = (reg)->exact + exact_size;
     }
 
-    if (IS_NOT_NULL(reg->int_map_backward)) {
-      if (COPY_FAILED(int_map_backward, sizeof(int) * ONIG_CHAR_TABLE_SIZE))
-        goto err_int_map_backward;
-    }
     if (IS_NOT_NULL(reg->p)) {
       if (COPY_FAILED(p, reg->alloc))
         goto err_p;
@@ -5649,8 +5644,6 @@ onig_reg_copy(regex_t** nreg, regex_t* oreg)
   err_repeat_range:
     xfree(reg->p);
   err_p:
-    xfree(reg->int_map_backward);
-  err_int_map_backward:
     xfree(reg->exact);
   err:
     xfree(reg);
@@ -5667,7 +5660,6 @@ onig_memsize(const regex_t *reg)
     if (IS_NULL(reg)) return 0;
     if (IS_NOT_NULL(reg->p))                size += reg->alloc;
     if (IS_NOT_NULL(reg->exact))            size += reg->exact_end - reg->exact;
-    if (IS_NOT_NULL(reg->int_map_backward)) size += sizeof(int) * ONIG_CHAR_TABLE_SIZE;
     if (IS_NOT_NULL(reg->repeat_range))     size += reg->repeat_range_alloc * sizeof(OnigRepeatRange);
     if (IS_NOT_NULL(reg->chain))            size += onig_memsize(reg->chain);
 
@@ -5952,7 +5944,6 @@ onig_reg_init(regex_t* reg, OnigOptionType option,
   (reg)->syntax           = syntax;
   (reg)->optimize         = 0;
   (reg)->exact            = (UChar* )NULL;
-  (reg)->int_map_backward = (int* )NULL;
   (reg)->chain            = (regex_t* )NULL;
 
   (reg)->p                = (UChar* )NULL;
diff --git a/regexec.c b/regexec.c
index 31be00864e..2e79623c71 100644
--- a/regexec.c
+++ b/regexec.c
@@ -4530,58 +4530,6 @@ bm_search_ic(regex_t* reg, const UChar* target, const UChar* target_end,
   return (UChar* )NULL;
 }
 
-#ifdef USE_INT_MAP_BACKWARD
-static int
-set_bm_backward_skip(UChar* s, UChar* end, OnigEncoding enc ARG_UNUSED,
-                     int** skip)
-{
-  int i, len;
-
-  if (IS_NULL(*skip)) {
-    *skip = (int* )xmalloc(sizeof(int) * ONIG_CHAR_TABLE_SIZE);
-    if (IS_NULL(*skip)) return ONIGERR_MEMORY;
-  }
-
-  len = (int )(end - s);
-  for (i = 0; i < ONIG_CHAR_TABLE_SIZE; i++)
-    (*skip)[i] = len;
-
-  for (i = len - 1; i > 0; i--)
-    (*skip)[s[i]] = i;
-
-  return 0;
-}
-
-static UChar*
-bm_search_backward(regex_t* reg, const UChar* target, const UChar* target_end,
-                   const UChar* text, const UChar* adjust_text,
-                   const UChar* text_end, const UChar* text_start)
-{
-  const UChar *s, *t, *p;
-
-  s = text_end - (target_end - target);
-  if (text_start < s)
-    s = text_start;
-  else
-    s = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc, adjust_text, s, text_end);
-
-  while (s >= text) {
-    p = s;
-    t = target;
-    while (t < target_end && *p == *t) {
-      p++; t++;
-    }
-    if (t == target_end)
-      return (UChar* )s;
-
-    s -= reg->int_map_backward[*s];
-    s = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc, adjust_text, s, text_end);
-  }
-
-  return (UChar* )NULL;
-}
-#endif
-
 static UChar*
 map_search(OnigEncoding enc, UChar map[],
            const UChar* text, const UChar* text_range, const UChar* text_end)
@@ -4828,21 +4776,7 @@ backward_search_range(regex_t* reg, const UChar* str, const UChar* end,
 
   case ONIG_OPTIMIZE_EXACT_BM:
   case ONIG_OPTIMIZE_EXACT_BM_NOT_REV:
-#ifdef USE_INT_MAP_BACKWARD
-    if (IS_NULL(reg->int_map_backward)) {
-      int r;
-      if (s - range < BM_BACKWARD_SEARCH_LENGTH_THRESHOLD)
-        goto exact_method;
-
-      r = set_bm_backward_skip(reg->exact, reg->exact_end, reg->enc,
-                               &(reg->int_map_backward));
-      if (r) return r;
-    }
-    p = bm_search_backward(reg, reg->exact, reg->exact_end, range, adjrange,
-                           end, p);
-#else
     goto exact_method;
-#endif
     break;
 
   case ONIG_OPTIMIZE_MAP: