From 027fa018a9cf6a0454d985a427e68bc72c70299d Mon Sep 17 00:00:00 2001
From: Eli Zaretskii <eliz@gnu.org>
Date: Wed, 24 Sep 2014 11:30:42 +0300
Subject: [PATCH] Remove the ignore_bn_limit ``optimization''.
---
src/bidi.c | 195 ++++++++++++-----------------------------------
src/dispextern.h | 1 -
2 files changed, 47 insertions(+), 149 deletions(-)
diff --git a/src/bidi.c b/src/bidi.c
index c2b5a983310..0614f5f0263 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -414,7 +414,6 @@ bidi_set_sos_type (struct bidi_it *bidi_it, int level_before, int level_after)
bidi_it->prev_for_neutral.bytepos = bidi_it->bytepos;
bidi_it->next_for_neutral.type = bidi_it->next_for_neutral.type_after_w1
= bidi_it->next_for_neutral.orig_type = UNKNOWN_BT;
- bidi_it->ignore_bn_limit = -1; /* meaning it's unknown */
}
/* Push the current embedding level and override status; reset the
@@ -760,7 +759,6 @@ bidi_cache_iterator_state (struct bidi_it *bidi_it, bool resolved)
bidi_cache[idx].invalid_levels = bidi_it->invalid_levels;
bidi_cache[idx].next_for_neutral = bidi_it->next_for_neutral;
bidi_cache[idx].next_for_ws = bidi_it->next_for_ws;
- bidi_cache[idx].ignore_bn_limit = bidi_it->ignore_bn_limit;
bidi_cache[idx].disp_pos = bidi_it->disp_pos;
bidi_cache[idx].disp_prop = bidi_it->disp_prop;
}
@@ -1014,7 +1012,7 @@ bidi_init_it (ptrdiff_t charpos, ptrdiff_t bytepos, bool frame_window_p,
if (bytepos >= 0)
bidi_it->bytepos = bytepos;
bidi_it->frame_window_p = frame_window_p;
- bidi_it->nchars = -1; /* to be computed in bidi_resolve_explicit_1 */
+ bidi_it->nchars = -1; /* to be computed in bidi_resolve_explicit */
bidi_it->first_elt = 1;
bidi_set_paragraph_end (bidi_it);
bidi_it->new_paragraph = 1;
@@ -1673,12 +1671,13 @@ bidi_explicit_dir_char (int ch)
|| ch_type == PDF);
}
-/* A helper function for bidi_resolve_explicit. It advances to the
- next character in logical order and determines the new embedding
- level and directional override, but does not take into account
- empty embeddings. */
+/* Given an iterator state in BIDI_IT, advance one character position
+ in the buffer/string to the next character (in the logical order),
+ resolve any explicit embeddings, directional overrides, and isolate
+ initiators and terminators, and return the embedding level of the
+ character after resolving these explicit directives. */
static int
-bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
+bidi_resolve_explicit (struct bidi_it *bidi_it)
{
int curchar;
bidi_type_t type, typ1, prev_type = UNKNOWN_BT;;
@@ -1789,64 +1788,50 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
bidi_it->type_after_w1 = type;
bidi_check_type (bidi_it->type_after_w1);
type = WEAK_BN; /* X9/Retaining */
- if (bidi_it->ignore_bn_limit <= -1)
+ if (current_level < BIDI_MAXDEPTH
+ && bidi_it->invalid_levels == 0
+ && bidi_it->invalid_isolates == 0)
{
- if (current_level < BIDI_MAXDEPTH
- && bidi_it->invalid_levels == 0
- && bidi_it->invalid_isolates == 0)
- {
- /* Compute the least odd embedding level greater than
- the current level. */
- new_level = ((current_level + 1) & ~1) + 1;
- if (bidi_it->type_after_w1 == RLE)
- override = NEUTRAL_DIR;
- else
- override = R2L;
- bidi_push_embedding_level (bidi_it, new_level, override, false);
- bidi_it->resolved_level = new_level;
- }
+ /* Compute the least odd embedding level greater than
+ the current level. */
+ new_level = ((current_level + 1) & ~1) + 1;
+ if (bidi_it->type_after_w1 == RLE)
+ override = NEUTRAL_DIR;
else
- {
- if (bidi_it->invalid_isolates == 0)
- bidi_it->invalid_levels++;
- }
+ override = R2L;
+ bidi_push_embedding_level (bidi_it, new_level, override, false);
+ bidi_it->resolved_level = new_level;
+ }
+ else
+ {
+ if (bidi_it->invalid_isolates == 0)
+ bidi_it->invalid_levels++;
}
- else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */
- || (bidi_it->next_en_pos > bidi_it->charpos
- && bidi_it->next_en_type == WEAK_EN))
- type = WEAK_EN;
break;
case LRE: /* X3 */
case LRO: /* X5 */
bidi_it->type_after_w1 = type;
bidi_check_type (bidi_it->type_after_w1);
type = WEAK_BN; /* X9/Retaining */
- if (bidi_it->ignore_bn_limit <= -1)
+ if (current_level < BIDI_MAXDEPTH - 1
+ && bidi_it->invalid_levels == 0
+ && bidi_it->invalid_isolates == 0)
{
- if (current_level < BIDI_MAXDEPTH - 1
- && bidi_it->invalid_levels == 0
- && bidi_it->invalid_isolates == 0)
- {
- /* Compute the least even embedding level greater than
- the current level. */
- new_level = ((current_level + 2) & ~1);
- if (bidi_it->type_after_w1 == LRE)
- override = NEUTRAL_DIR;
- else
- override = L2R;
- bidi_push_embedding_level (bidi_it, new_level, override, false);
- bidi_it->resolved_level = new_level;
- }
+ /* Compute the least even embedding level greater than
+ the current level. */
+ new_level = ((current_level + 2) & ~1);
+ if (bidi_it->type_after_w1 == LRE)
+ override = NEUTRAL_DIR;
else
- {
- if (bidi_it->invalid_isolates == 0)
- bidi_it->invalid_levels++;
- }
+ override = L2R;
+ bidi_push_embedding_level (bidi_it, new_level, override, false);
+ bidi_it->resolved_level = new_level;
+ }
+ else
+ {
+ if (bidi_it->invalid_isolates == 0)
+ bidi_it->invalid_levels++;
}
- else if (bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */
- || (bidi_it->next_en_pos > bidi_it->charpos
- && bidi_it->next_en_type == WEAK_EN))
- type = WEAK_EN;
break;
case PDI: /* X6a */
if (bidi_it->invalid_isolates)
@@ -1876,11 +1861,6 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
bidi_it->type_after_w1 = type;
bidi_check_type (bidi_it->type_after_w1);
type = WEAK_BN; /* X9/Retaining */
- if (bidi_it->ignore_bn_limit > -1
- && bidi_it->prev.type_after_w1 == WEAK_EN /* W5/Retaining */
- || (bidi_it->next_en_pos > bidi_it->charpos
- && bidi_it->next_en_type == WEAK_EN))
- type = WEAK_EN;
break;
default:
/* LRI, RLI, and FSI increment, and PDF decrements, the
@@ -1947,17 +1927,14 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
bidi_it->invalid_isolates++;
break;
case PDF: /* X7 */
- if (bidi_it->ignore_bn_limit <= -1)
+ if (!bidi_it->invalid_isolates)
{
- if (!bidi_it->invalid_isolates)
- {
- if (bidi_it->invalid_levels)
- bidi_it->invalid_levels--;
- else if (!isolate_status && bidi_it->stack_idx >= 1)
- new_level = bidi_pop_embedding_level (bidi_it);
- }
- bidi_it->resolved_level = new_level;
+ if (bidi_it->invalid_levels)
+ bidi_it->invalid_levels--;
+ else if (!isolate_status && bidi_it->stack_idx >= 1)
+ new_level = bidi_pop_embedding_level (bidi_it);
}
+ bidi_it->resolved_level = new_level;
break;
default:
/* Nothing. */
@@ -1968,85 +1945,15 @@ bidi_resolve_explicit_1 (struct bidi_it *bidi_it)
bidi_it->type = type;
bidi_check_type (bidi_it->type);
- eassert (bidi_it->resolved_level >= 0);
- return bidi_it->resolved_level;
-}
-
-/* Given an iterator state in BIDI_IT, advance one character position
- in the buffer/string to the next character (in the logical order),
- resolve any explicit embeddings and directional overrides, and
- return the embedding level of the character after resolving
- explicit directives and ignoring empty embeddings. */
-static int
-bidi_resolve_explicit (struct bidi_it *bidi_it)
-{
- int prev_level = bidi_it->level_stack[bidi_it->stack_idx].level;
- int new_level = bidi_resolve_explicit_1 (bidi_it);
- ptrdiff_t eob = bidi_it->string.s ? bidi_it->string.schars : ZV;
- const unsigned char *s
- = (STRINGP (bidi_it->string.lstring)
- ? SDATA (bidi_it->string.lstring)
- : bidi_it->string.s);
-
- eassert (prev_level >= 0);
- if (prev_level < new_level
- && bidi_it->type == WEAK_BN
- && bidi_it->ignore_bn_limit == -1 /* only if not already known */
- && bidi_it->charpos < eob /* not already at EOB */
- && bidi_explicit_dir_char (bidi_char_at_pos (bidi_it->bytepos
- + bidi_it->ch_len, s,
- bidi_it->string.unibyte)))
- {
- /* Avoid pushing and popping embedding levels if the level run
- is empty, as this breaks level runs where it shouldn't.
- UAX#9 removes all the explicit embedding and override codes,
- so empty embeddings disappear without a trace. We need to
- behave as if we did the same. */
- struct bidi_it saved_it;
- int level = prev_level;
-
- bidi_copy_it (&saved_it, bidi_it);
-
- while (bidi_explicit_dir_char (bidi_char_at_pos (bidi_it->bytepos
- + bidi_it->ch_len, s,
- bidi_it->string.unibyte)))
- {
- /* This advances to the next character, skipping any
- characters covered by display strings. */
- level = bidi_resolve_explicit_1 (bidi_it);
- /* If string.lstring was relocated inside bidi_resolve_explicit_1,
- a pointer to its data is no longer valid. */
- if (STRINGP (bidi_it->string.lstring))
- s = SDATA (bidi_it->string.lstring);
- }
-
- if (bidi_it->nchars <= 0)
- emacs_abort ();
- if (level == prev_level) /* empty embedding */
- saved_it.ignore_bn_limit = bidi_it->charpos + bidi_it->nchars;
- else /* this embedding is non-empty */
- saved_it.ignore_bn_limit = -2;
-
- bidi_copy_it (bidi_it, &saved_it);
- if (bidi_it->ignore_bn_limit > -1)
- {
- /* We pushed a level, but we shouldn't have. Undo that. */
- if (!bidi_it->invalid_levels)
- new_level = bidi_pop_embedding_level (bidi_it);
- else
- bidi_it->invalid_levels--;
- }
- }
-
if (bidi_it->type == NEUTRAL_B) /* X8 */
{
bidi_set_paragraph_end (bidi_it);
/* This is needed by bidi_resolve_weak below, and in L1. */
bidi_it->type_after_w1 = bidi_it->type;
- bidi_check_type (bidi_it->type_after_w1);
}
- return new_level;
+ eassert (bidi_it->resolved_level >= 0);
+ return bidi_it->resolved_level;
}
static bool
@@ -2474,14 +2381,6 @@ bidi_type_of_next_char (struct bidi_it *bidi_it)
if (bidi_it->scan_dir != 1)
emacs_abort ();
- /* Reset the limit until which to ignore BNs if we step out of the
- area where we found only empty levels. */
- if ((bidi_it->ignore_bn_limit > -1
- && bidi_it->ignore_bn_limit <= bidi_it->charpos)
- || (bidi_it->ignore_bn_limit == -2
- && !bidi_explicit_dir_char (bidi_it->ch)))
- bidi_it->ignore_bn_limit = -1;
-
type = bidi_resolve_neutral (bidi_it);
return type;
diff --git a/src/dispextern.h b/src/dispextern.h
index e0701f34a41..c823194bd6b 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1959,7 +1959,6 @@ struct bidi_it {
struct bidi_saved_info next_for_ws; /* character after sequence of ws */
ptrdiff_t next_en_pos; /* pos. of next char for determining ET type */
bidi_type_t next_en_type; /* type of char at next_en_pos */
- ptrdiff_t ignore_bn_limit; /* position until which to ignore BNs */
bidi_dir_t sos; /* direction of start-of-sequence in effect */
int scan_dir; /* direction of text scan, 1: forw, -1: back */
ptrdiff_t disp_pos; /* position of display string after ch */
--
2.39.5