kc3-lang/harfbuzz/src/hb-set.hh

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• Hash : b1862743
  Author :
  Date : 2018-10-29T23:21:14
  

  [set/map] Fix uninitialized memory
  
  I keep forgetting that primitive types are NOT initialized during construction. :|
  

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• src/hb-set.hh

• /*
   * Copyright © 2012,2017  Google, Inc.
   *
   *  This is part of HarfBuzz, a text shaping library.
   *
   * Permission is hereby granted, without written agreement and without
   * license or royalty fees, to use, copy, modify, and distribute this
   * software and its documentation for any purpose, provided that the
   * above copyright notice and the following two paragraphs appear in
   * all copies of this software.
   *
   * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
   * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
   * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
   * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
   * DAMAGE.
   *
   * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
   * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
   * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
   * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
   *
   * Google Author(s): Behdad Esfahbod
   */
  
  #ifndef HB_SET_HH
  #define HB_SET_HH
  
  #include "hb.hh"
  
  
  /*
   * hb_set_t
   */
  
  /* TODO Keep a free-list so we can free pages that are completely zeroed.  At that
   * point maybe also use a sentinel value for "all-1" pages? */
  
  struct hb_set_t
  {
    HB_NO_COPY_ASSIGN (hb_set_t);
    inline hb_set_t (void) { init (); }
    inline ~hb_set_t (void) { fini (); }
  
    struct page_map_t
    {
      inline int cmp (const page_map_t *o) const { return (int) o->major - (int) major; }
  
      uint32_t major;
      uint32_t index;
    };
  
    struct page_t
    {
      inline void init0 (void) { memset (&v, 0, sizeof (v)); }
      inline void init1 (void) { memset (&v, 0xff, sizeof (v)); }
  
      inline unsigned int len (void) const
      { return ARRAY_LENGTH_CONST (v); }
  
      inline bool is_empty (void) const
      {
        for (unsigned int i = 0; i < len (); i++)
          if (v[i])
  	  return false;
        return true;
      }
  
      inline void add (hb_codepoint_t g) { elt (g) |= mask (g); }
      inline void del (hb_codepoint_t g) { elt (g) &= ~mask (g); }
      inline bool has (hb_codepoint_t g) const { return !!(elt (g) & mask (g)); }
  
      inline void add_range (hb_codepoint_t a, hb_codepoint_t b)
      {
        elt_t *la = &elt (a);
        elt_t *lb = &elt (b);
        if (la == lb)
          *la |= (mask (b) << 1) - mask(a);
        else
        {
  	*la |= ~(mask (a) - 1);
  	la++;
  
  	memset (la, 0xff, (char *) lb - (char *) la);
  
  	*lb |= ((mask (b) << 1) - 1);
        }
      }
  
      inline bool is_equal (const page_t *other) const
      {
        return 0 == memcmp (&v, &other->v, sizeof (v));
      }
  
      inline unsigned int get_population (void) const
      {
        unsigned int pop = 0;
        for (unsigned int i = 0; i < len (); i++)
          pop += hb_popcount (v[i]);
        return pop;
      }
  
      inline bool next (hb_codepoint_t *codepoint) const
      {
        unsigned int m = (*codepoint + 1) & MASK;
        if (!m)
        {
  	*codepoint = INVALID;
  	return false;
        }
        unsigned int i = m / ELT_BITS;
        unsigned int j = m & ELT_MASK;
  
        const elt_t vv = v[i] & ~((elt_t (1) << j) - 1);
        for (const elt_t *p = &vv; i < len (); p = &v[++i])
  	if (*p)
  	{
  	  *codepoint = i * ELT_BITS + elt_get_min (*p);
  	  return true;
  	}
  
        *codepoint = INVALID;
        return false;
      }
      inline bool previous (hb_codepoint_t *codepoint) const
      {
        unsigned int m = (*codepoint - 1) & MASK;
        if (m == MASK)
        {
  	*codepoint = INVALID;
  	return false;
        }
        unsigned int i = m / ELT_BITS;
        unsigned int j = m & ELT_MASK;
  
        const elt_t vv = v[i] & ((elt_t (1) << (j + 1)) - 1);
        for (const elt_t *p = &vv; (int) i >= 0; p = &v[--i])
  	if (*p)
  	{
  	  *codepoint = i * ELT_BITS + elt_get_max (*p);
  	  return true;
  	}
  
        *codepoint = INVALID;
        return false;
      }
      inline hb_codepoint_t get_min (void) const
      {
        for (unsigned int i = 0; i < len (); i++)
          if (v[i])
  	  return i * ELT_BITS + elt_get_min (v[i]);
        return INVALID;
      }
      inline hb_codepoint_t get_max (void) const
      {
        for (int i = len () - 1; i >= 0; i--)
          if (v[i])
  	  return i * ELT_BITS + elt_get_max (v[i]);
        return 0;
      }
  
      typedef unsigned long long elt_t;
      enum { PAGE_BITS = 512 };
      static_assert ((PAGE_BITS & ((PAGE_BITS) - 1)) == 0, "");
  
      static inline unsigned int elt_get_min (const elt_t &elt) { return hb_ctz (elt); }
      static inline unsigned int elt_get_max (const elt_t &elt) { return hb_bit_storage (elt) - 1; }
  
      typedef hb_vector_size_t<elt_t, PAGE_BITS / 8> vector_t;
  
      enum { ELT_BITS = sizeof (elt_t) * 8 };
      enum { ELT_MASK = ELT_BITS - 1 };
      enum { BITS = sizeof (vector_t) * 8 };
      enum { MASK = BITS - 1 };
      static_assert ((unsigned) PAGE_BITS == (unsigned) BITS, "");
  
      elt_t &elt (hb_codepoint_t g) { return v[(g & MASK) / ELT_BITS]; }
      elt_t const &elt (hb_codepoint_t g) const { return v[(g & MASK) / ELT_BITS]; }
      elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & ELT_MASK); }
  
      vector_t v;
    };
    static_assert (page_t::PAGE_BITS == sizeof (page_t) * 8, "");
  
    hb_object_header_t header;
    bool successful; /* Allocations successful */
    mutable unsigned int population;
    hb_vector_t<page_map_t, 1> page_map;
    hb_vector_t<page_t, 1> pages;
  
    inline void init_shallow (void)
    {
      successful = true;
      population = 0;
      page_map.init ();
      pages.init ();
    }
    inline void init (void)
    {
      hb_object_init (this);
      init_shallow ();
    }
    inline void fini_shallow (void)
    {
      population = 0;
      page_map.fini ();
      pages.fini ();
    }
    inline void fini (void)
    {
      hb_object_fini (this);
      fini_shallow ();
    }
  
    inline bool resize (unsigned int count)
    {
      if (unlikely (!successful)) return false;
      if (!pages.resize (count) || !page_map.resize (count))
      {
        pages.resize (page_map.len);
        successful = false;
        return false;
      }
      return true;
    }
  
    inline void clear (void) {
      if (unlikely (hb_object_is_inert (this)))
        return;
      successful = true;
      population = 0;
      page_map.resize (0);
      pages.resize (0);
    }
    inline bool is_empty (void) const {
      unsigned int count = pages.len;
      for (unsigned int i = 0; i < count; i++)
        if (!pages[i].is_empty ())
          return false;
      return true;
    }
  
    inline void dirty (void) { population = (unsigned int) -1; }
  
    inline void add (hb_codepoint_t g)
    {
      if (unlikely (!successful)) return;
      if (unlikely (g == INVALID)) return;
      dirty ();
      page_t *page = page_for_insert (g); if (unlikely (!page)) return;
      page->add (g);
    }
    inline bool add_range (hb_codepoint_t a, hb_codepoint_t b)
    {
      if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */
      if (unlikely (a > b || a == INVALID || b == INVALID)) return false;
      dirty ();
      unsigned int ma = get_major (a);
      unsigned int mb = get_major (b);
      if (ma == mb)
      {
        page_t *page = page_for_insert (a); if (unlikely (!page)) return false;
        page->add_range (a, b);
      }
      else
      {
        page_t *page = page_for_insert (a); if (unlikely (!page)) return false;
        page->add_range (a, major_start (ma + 1) - 1);
  
        for (unsigned int m = ma + 1; m < mb; m++)
        {
  	page = page_for_insert (major_start (m)); if (unlikely (!page)) return false;
  	page->init1 ();
        }
  
        page = page_for_insert (b); if (unlikely (!page)) return false;
        page->add_range (major_start (mb), b);
      }
      return true;
    }
  
    template <typename T>
    inline void add_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
    {
      if (unlikely (!successful)) return;
      if (!count) return;
      dirty ();
      hb_codepoint_t g = *array;
      while (count)
      {
        unsigned int m = get_major (g);
        page_t *page = page_for_insert (g); if (unlikely (!page)) return;
        unsigned int start = major_start (m);
        unsigned int end = major_start (m + 1);
        do
        {
  	page->add (g);
  
  	array = (const T *) ((const char *) array + stride);
  	count--;
        }
        while (count && (g = *array, start <= g && g < end));
      }
    }
  
    /* Might return false if array looks unsorted.
     * Used for faster rejection of corrupt data. */
    template <typename T>
    inline bool add_sorted_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
    {
      if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */
      if (!count) return true;
      dirty ();
      hb_codepoint_t g = *array;
      hb_codepoint_t last_g = g;
      while (count)
      {
        unsigned int m = get_major (g);
        page_t *page = page_for_insert (g); if (unlikely (!page)) return false;
        unsigned int end = major_start (m + 1);
        do
        {
          /* If we try harder we can change the following comparison to <=;
  	 * Not sure if it's worth it. */
          if (g < last_g) return false;
  	last_g = g;
  	page->add (g);
  
  	array = (const T *) ((const char *) array + stride);
  	count--;
        }
        while (count && (g = *array, g < end));
      }
      return true;
    }
  
    inline void del (hb_codepoint_t g)
    {
      /* TODO perform op even if !successful. */
      if (unlikely (!successful)) return;
      page_t *p = page_for (g);
      if (!p)
        return;
      dirty ();
      p->del (g);
    }
    inline void del_range (hb_codepoint_t a, hb_codepoint_t b)
    {
      /* TODO perform op even if !successful. */
      /* TODO Optimize, like add_range(). */
      if (unlikely (!successful)) return;
      for (unsigned int i = a; i < b + 1; i++)
        del (i);
    }
    inline bool has (hb_codepoint_t g) const
    {
      const page_t *p = page_for (g);
      if (!p)
        return false;
      return p->has (g);
    }
    inline bool intersects (hb_codepoint_t first,
  			  hb_codepoint_t last) const
    {
      hb_codepoint_t c = first - 1;
      return next (&c) && c <= last;
    }
    inline void set (const hb_set_t *other)
    {
      if (unlikely (!successful)) return;
      unsigned int count = other->pages.len;
      if (!resize (count))
        return;
      population = other->population;
      memcpy (pages, other->pages, count * sizeof (pages[0]));
      memcpy (page_map, other->page_map, count * sizeof (page_map[0]));
    }
  
    inline bool is_equal (const hb_set_t *other) const
    {
      if (get_population () != other->get_population ())
        return false;
  
      unsigned int na = pages.len;
      unsigned int nb = other->pages.len;
  
      unsigned int a = 0, b = 0;
      for (; a < na && b < nb; )
      {
        if (page_at (a).is_empty ()) { a++; continue; }
        if (other->page_at (b).is_empty ()) { b++; continue; }
        if (page_map[a].major != other->page_map[b].major ||
  	  !page_at (a).is_equal (&other->page_at (b)))
          return false;
        a++;
        b++;
      }
      for (; a < na; a++)
        if (!page_at (a).is_empty ()) { return false; }
      for (; b < nb; b++)
        if (!other->page_at (b).is_empty ()) { return false; }
  
      return true;
    }
  
    inline bool is_subset (const hb_set_t *larger_set) const
    {
      if (get_population () > larger_set->get_population ())
        return false;
  
      /* TODO Optimize to use pages. */
      hb_codepoint_t c = INVALID;
      while (next (&c))
        if (!larger_set->has (c))
          return false;
  
      return true;
    }
  
    template <class Op>
    inline void process (const hb_set_t *other)
    {
      if (unlikely (!successful)) return;
  
      dirty ();
  
      unsigned int na = pages.len;
      unsigned int nb = other->pages.len;
      unsigned int next_page = na;
  
      unsigned int count = 0, newCount = 0;
      unsigned int a = 0, b = 0;
      for (; a < na && b < nb; )
      {
        if (page_map[a].major == other->page_map[b].major)
        {
          count++;
  	a++;
  	b++;
        }
        else if (page_map[a].major < other->page_map[b].major)
        {
          if (Op::passthru_left)
  	  count++;
          a++;
        }
        else
        {
          if (Op::passthru_right)
  	  count++;
          b++;
        }
      }
      if (Op::passthru_left)
        count += na - a;
      if (Op::passthru_right)
        count += nb - b;
  
      if (count > pages.len)
        if (!resize (count))
          return;
      newCount = count;
  
      /* Process in-place backward. */
      a = na;
      b = nb;
      for (; a && b; )
      {
        if (page_map[a - 1].major == other->page_map[b - 1].major)
        {
  	a--;
  	b--;
  	count--;
  	page_map[count] = page_map[a];
  	Op::process (page_at (count).v, page_at (a).v, other->page_at (b).v);
        }
        else if (page_map[a - 1].major > other->page_map[b - 1].major)
        {
  	a--;
  	if (Op::passthru_left)
  	{
  	  count--;
  	  page_map[count] = page_map[a];
  	}
        }
        else
        {
  	b--;
  	if (Op::passthru_right)
  	{
  	  count--;
  	  page_map[count].major = other->page_map[b].major;
  	  page_map[count].index = next_page++;
  	  page_at (count).v = other->page_at (b).v;
  	}
        }
      }
      if (Op::passthru_left)
        while (a)
        {
  	a--;
  	count--;
  	page_map[count] = page_map [a];
        }
      if (Op::passthru_right)
        while (b)
        {
  	b--;
  	count--;
  	page_map[count].major = other->page_map[b].major;
  	page_map[count].index = next_page++;
  	page_at (count).v = other->page_at (b).v;
        }
      assert (!count);
      if (pages.len > newCount)
        resize (newCount);
    }
  
    inline void union_ (const hb_set_t *other)
    {
      process<HbOpOr> (other);
    }
    inline void intersect (const hb_set_t *other)
    {
      process<HbOpAnd> (other);
    }
    inline void subtract (const hb_set_t *other)
    {
      process<HbOpMinus> (other);
    }
    inline void symmetric_difference (const hb_set_t *other)
    {
      process<HbOpXor> (other);
    }
    inline bool next (hb_codepoint_t *codepoint) const
    {
      if (unlikely (*codepoint == INVALID)) {
        *codepoint = get_min ();
        return *codepoint != INVALID;
      }
  
      page_map_t map = {get_major (*codepoint), 0};
      unsigned int i;
      page_map.bfind (map, &i);
      if (i < page_map.len && page_map[i].major == map.major)
      {
        if (pages[page_map[i].index].next (codepoint))
        {
  	*codepoint += page_map[i].major * page_t::PAGE_BITS;
  	return true;
        }
        i++;
      }
      for (; i < page_map.len; i++)
      {
        hb_codepoint_t m = pages[page_map[i].index].get_min ();
        if (m != INVALID)
        {
  	*codepoint = page_map[i].major * page_t::PAGE_BITS + m;
  	return true;
        }
      }
      *codepoint = INVALID;
      return false;
    }
    inline bool previous (hb_codepoint_t *codepoint) const
    {
      if (unlikely (*codepoint == INVALID)) {
        *codepoint = get_max ();
        return *codepoint != INVALID;
      }
  
      page_map_t map = {get_major (*codepoint), 0};
      unsigned int i;
      page_map.bfind (map, &i);
      if (i < page_map.len && page_map[i].major == map.major)
      {
        if (pages[page_map[i].index].previous (codepoint))
        {
  	*codepoint += page_map[i].major * page_t::PAGE_BITS;
  	return true;
        }
      }
      i--;
      for (; (int) i >= 0; i--)
      {
        hb_codepoint_t m = pages[page_map[i].index].get_max ();
        if (m != INVALID)
        {
  	*codepoint = page_map[i].major * page_t::PAGE_BITS + m;
  	return true;
        }
      }
      *codepoint = INVALID;
      return false;
    }
    inline bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const
    {
      hb_codepoint_t i;
  
      i = *last;
      if (!next (&i))
      {
        *last = *first = INVALID;
        return false;
      }
  
      /* TODO Speed up. */
      *last = *first = i;
      while (next (&i) && i == *last + 1)
        (*last)++;
  
      return true;
    }
    inline bool previous_range (hb_codepoint_t *first, hb_codepoint_t *last) const
    {
      hb_codepoint_t i;
  
      i = *first;
      if (!previous (&i))
      {
        *last = *first = INVALID;
        return false;
      }
  
      /* TODO Speed up. */
      *last = *first = i;
      while (previous (&i) && i == *first - 1)
        (*first)--;
  
      return true;
    }
  
    inline unsigned int get_population (void) const
    {
      if (population != (unsigned int) -1)
        return population;
  
      unsigned int pop = 0;
      unsigned int count = pages.len;
      for (unsigned int i = 0; i < count; i++)
        pop += pages[i].get_population ();
  
      population = pop;
      return pop;
    }
    inline hb_codepoint_t get_min (void) const
    {
      unsigned int count = pages.len;
      for (unsigned int i = 0; i < count; i++)
        if (!page_at (i).is_empty ())
          return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_min ();
      return INVALID;
    }
    inline hb_codepoint_t get_max (void) const
    {
      unsigned int count = pages.len;
      for (int i = count - 1; i >= 0; i++)
        if (!page_at (i).is_empty ())
          return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_max ();
      return INVALID;
    }
  
    static  const hb_codepoint_t INVALID = HB_SET_VALUE_INVALID;
  
    inline page_t *page_for_insert (hb_codepoint_t g)
    {
      page_map_t map = {get_major (g), pages.len};
      unsigned int i;
      if (!page_map.bfind (map, &i))
      {
        if (!resize (pages.len + 1))
  	return nullptr;
  
        pages[map.index].init0 ();
        memmove (page_map + i + 1,
  	       page_map + i,
  	       (page_map.len - 1 - i) * sizeof (page_map[0]));
        page_map[i] = map;
      }
      return &pages[page_map[i].index];
    }
    inline page_t *page_for (hb_codepoint_t g)
    {
      page_map_t key = {get_major (g)};
      const page_map_t *found = page_map.bsearch (key);
      if (found)
        return &pages[found->index];
      return nullptr;
    }
    inline const page_t *page_for (hb_codepoint_t g) const
    {
      page_map_t key = {get_major (g)};
      const page_map_t *found = page_map.bsearch (key);
      if (found)
        return &pages[found->index];
      return nullptr;
    }
    inline page_t &page_at (unsigned int i) { return pages[page_map[i].index]; }
    inline const page_t &page_at (unsigned int i) const { return pages[page_map[i].index]; }
    inline unsigned int get_major (hb_codepoint_t g) const { return g / page_t::PAGE_BITS; }
    inline hb_codepoint_t major_start (unsigned int major) const { return major * page_t::PAGE_BITS; }
  };
  
  
  #endif /* HB_SET_HH */
  

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