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| author | Paul Eggert <eggert@cs.ucla.edu> | 2017-06-21 17:18:30 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2017-06-21 17:27:58 -0700 |
| commit | 35caaf713fb3c3e5e826e52b37e1b389c6bd9cce (patch) | |
| tree | 958d4ccfe87ae8bfb3b8537ec251a971a2137fa8 | |
| parent | 07a3386fbb4e180f017fab11ea963f4f34493f3c (diff) | |
| download | emacs-35caaf713fb3c3e5e826e52b37e1b389c6bd9cce.tar.gz | |
Limit bidi_find_bracket_pairs to MAX_ALLOCA
* src/bidi.c (MAX_BPA_STACK): Now a constant, not a macro.
Shrink it to allow for the two struct bidi_it objects in
the same frame.
(PUSH_BPA_STACK): Avoid integer overflow with enormous bidi cache.
(bidi_find_bracket_pairs): Use compile-time check instead of runtime.
| -rw-r--r-- | src/bidi.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/src/bidi.c b/src/bidi.c index dce0bf695f6..e34da778ba0 100644 --- a/src/bidi.c +++ b/src/bidi.c @@ -565,9 +565,7 @@ bidi_copy_it (struct bidi_it *to, struct bidi_it *from) RTL characters in the offending line of text. */ /* Do we need to allow customization of this limit? */ #define BIDI_CACHE_MAX_ELTS_PER_SLOT 50000 -#if BIDI_CACHE_CHUNK >= BIDI_CACHE_MAX_ELTS_PER_SLOT -# error BIDI_CACHE_CHUNK must be less than BIDI_CACHE_MAX_ELTS_PER_SLOT -#endif +verify (BIDI_CACHE_CHUNK < BIDI_CACHE_MAX_ELTS_PER_SLOT); static ptrdiff_t bidi_cache_max_elts = BIDI_CACHE_MAX_ELTS_PER_SLOT; static struct bidi_it *bidi_cache; static ptrdiff_t bidi_cache_size = 0; @@ -2468,9 +2466,11 @@ typedef struct bpa_stack_entry { unsigned flags : 2; } bpa_stack_entry; -/* With MAX_ALLOCA of 16KB, this should allow at least 1K slots in the +/* Allow for the two struct bidi_it objects too, since they can be big. + With MAX_ALLOCA of 16 KiB, this should allow at least 900 slots in the BPA stack, which should be more than enough for actual bidi text. */ -#define MAX_BPA_STACK ((int)max (MAX_ALLOCA / sizeof (bpa_stack_entry), 1)) +enum { MAX_BPA_STACK = max (1, ((MAX_ALLOCA - 2 * sizeof (struct bidi_it)) + / sizeof (bpa_stack_entry))) }; /* UAX#9 says to match opening brackets with the matching closing brackets or their canonical equivalents. As of Unicode 8.0, there @@ -2517,7 +2517,7 @@ typedef struct bpa_stack_entry { #define PUSH_BPA_STACK \ do { \ int ch; \ - if (bpa_sp < MAX_BPA_STACK - 1) \ + if (bpa_sp < MAX_BPA_STACK - 1 && bidi_cache_last_idx <= INT_MAX) \ { \ bpa_sp++; \ ch = CANONICAL_EQU (bidi_it->ch); \ @@ -2563,7 +2563,7 @@ bidi_find_bracket_pairs (struct bidi_it *bidi_it) ptrdiff_t pairing_pos; int idx_at_entry = bidi_cache_idx; - eassert (MAX_BPA_STACK >= 100); + verify (MAX_BPA_STACK >= 100); bidi_copy_it (&saved_it, bidi_it); /* bidi_cache_iterator_state refuses to cache on backward scans, and bidi_cache_fetch_state doesn't bring scan_dir from the |