The Tor Browser: gfx/graphite2/src/Silf.cpp@b8a032363ba2 (annotated)

gfx/graphite2/src/Silf.cpp@b8a032363ba2 (annotated)

gfx/graphite2/src/Silf.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*  GRAPHITE2 LICENSING
     Copyright 2010, SIL International
     All rights reserved.
     This library is free software; you can redistribute it and/or modify
     it under the terms of the GNU Lesser General Public License as published
     by the Free Software Foundation; either version 2.1 of License, or
     (at your option) any later version.
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
     You should also have received a copy of the GNU Lesser General Public
     License along with this library in the file named "LICENSE".
     If not, write to the Free Software Foundation, 51 Franklin Street,
     Suite 500, Boston, MA 02110-1335, USA or visit their web page on the
     internet at http://www.fsf.org/licenses/lgpl.html.
 Alternatively, the contents of this file may be used under the terms of the
 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
 License, as published by the Free Software Foundation, either version 2
 of the License or (at your option) any later version.
 */
 #include <cstdlib>
 #include "graphite2/Segment.h"
 #include "inc/debug.h"
 #include "inc/Endian.h"
 #include "inc/Silf.h"
 #include "inc/Segment.h"
 #include "inc/Rule.h"
 #include "inc/Error.h"
 using namespace graphite2;
 namespace { static const uint32 ERROROFFSET = 0xFFFFFFFF; }
 Silf::Silf() throw()
 : m_passes(0),
   m_pseudos(0),
   m_classOffsets(0),
   m_classData(0),
   m_justs(0),
   m_numPasses(0),
   m_numJusts(0),
   m_sPass(0),
   m_pPass(0),
   m_jPass(0),
   m_bPass(0),
   m_flags(0),
   m_aPseudo(0),
   m_aBreak(0),
   m_aUser(0),
   m_aBidi(0),
   m_aMirror(0),
   m_aPassBits(0),
   m_iMaxComp(0),
   m_aLig(0),
   m_numPseudo(0),
   m_nClass(0),
   m_nLinear(0),
   m_gEndLine(0)
 {
     memset(&m_silfinfo, 0, sizeof m_silfinfo);
 }
 Silf::~Silf() throw()
 {
     releaseBuffers();
 }
 void Silf::releaseBuffers() throw()
 {
     delete [] m_passes;
     delete [] m_pseudos;
     free(m_classOffsets);
     free(m_classData);
     free(m_justs);
     m_passes= 0;
     m_pseudos = 0;
     m_classOffsets = 0;
     m_classData = 0;
     m_justs = 0;
 }
 bool Silf::readGraphite(const byte * const silf_start, size_t lSilf, Face& face, uint32 version)
 {
     const byte * p = silf_start,
                * const silf_end = p + lSilf;
     Error e;
     if (version >= 0x00030000)
     {
         if (e.test(lSilf < 28, E_BADSIZE)) { releaseBuffers(); return face.error(e); }
         be::skip<int32>(p);    // ruleVersion
         be::skip<uint16>(p,2); // passOffset & pseudosOffset
     }
     else if (e.test(lSilf < 20, E_BADSIZE)) { releaseBuffers(); return face.error(e); }
     const uint16 maxGlyph = be::read<uint16>(p);
     m_silfinfo.extra_ascent = be::read<uint16>(p);
     m_silfinfo.extra_descent = be::read<uint16>(p);
     m_numPasses = be::read<uint8>(p);
     m_sPass     = be::read<uint8>(p);
     m_pPass     = be::read<uint8>(p);
     m_jPass     = be::read<uint8>(p);
     m_bPass     = be::read<uint8>(p);
     m_flags     = be::read<uint8>(p);
     be::skip<uint8>(p,2); //  max{Pre,Post}Context.
     m_aPseudo   = be::read<uint8>(p);
     m_aBreak    = be::read<uint8>(p);
     m_aBidi     = be::read<uint8>(p);
     m_aMirror   = be::read<uint8>(p);
     m_aPassBits = be::read<uint8>(p);
     // Read Justification levels.
     m_numJusts  = be::read<uint8>(p);
     if (e.test(maxGlyph >= face.glyphs().numGlyphs(), E_BADMAXGLYPH)
         || e.test(p + m_numJusts * 8 >= silf_end, E_BADNUMJUSTS))
     {
         releaseBuffers(); return face.error(e);
     }
     if (m_numJusts)
     {
         m_justs = gralloc<Justinfo>(m_numJusts);
         if (e.test(!m_justs, E_OUTOFMEM)) return face.error(e);
         for (uint8 i = 0; i < m_numJusts; i++)
         {
             ::new(m_justs + i) Justinfo(p[0], p[1], p[2], p[3]);
             be::skip<byte>(p,8);
         }
     }
     if (e.test(p + sizeof(uint16) + sizeof(uint8)*8 >= silf_end, E_BADENDJUSTS)) { releaseBuffers(); return face.error(e); }
     m_aLig      = be::read<uint16>(p);
     m_aUser     = be::read<uint8>(p);
     m_iMaxComp  = be::read<uint8>(p);
     be::skip<byte>(p,5);                        // direction and 4 reserved bytes
     be::skip<uint16>(p, be::read<uint8>(p));    // don't need critical features yet
     be::skip<byte>(p);                          // reserved
     if (e.test(p >= silf_end, E_BADCRITFEATURES))   { releaseBuffers(); return face.error(e); }
     be::skip<uint32>(p, be::read<uint8>(p));    // don't use scriptTag array.
     if (e.test(p + sizeof(uint16) + sizeof(uint32) >= silf_end, E_BADSCRIPTTAGS)) { releaseBuffers(); return face.error(e); }
     m_gEndLine  = be::read<uint16>(p);          // lbGID
     const byte * o_passes = p,
                * const passes_start = silf_start + be::read<uint32>(p);
     const size_t num_attrs = face.glyphs().numAttrs();
     if (e.test(m_aPseudo   >= num_attrs, E_BADAPSEUDO)
         || e.test(m_aBreak >= num_attrs, E_BADABREAK)
         || e.test(m_aBidi  >= num_attrs, E_BADABIDI)
         || e.test(m_aMirror>= num_attrs, E_BADAMIRROR)
         || e.test(m_numPasses > 128, E_BADNUMPASSES) || e.test(passes_start >= silf_end, E_BADPASSESSTART)
         || e.test(m_pPass < m_sPass, E_BADPASSBOUND) || e.test(m_pPass > m_numPasses, E_BADPPASS) || e.test(m_sPass > m_numPasses, E_BADSPASS)
         || e.test(m_jPass < m_pPass, E_BADJPASSBOUND) || e.test(m_jPass > m_numPasses, E_BADJPASS)
         || e.test((m_bPass != 0xFF && (m_bPass < m_jPass || m_bPass > m_numPasses)), E_BADBPASS)
         || e.test(m_aLig > 127, E_BADALIG))
     {
         releaseBuffers();
         return face.error(e);
     }
     be::skip<uint32>(p, m_numPasses);
     if (e.test(p + sizeof(uint16) >= passes_start, E_BADPASSESSTART)) { releaseBuffers(); return face.error(e); }
     m_numPseudo = be::read<uint16>(p);
     be::skip<uint16>(p, 3); // searchPseudo, pseudoSelector, pseudoShift
     if (e.test(p + m_numPseudo*(sizeof(uint32) + sizeof(uint16)) >= passes_start, E_BADNUMPSEUDO))
     {
         releaseBuffers(); return face.error(e);
     }
     m_pseudos = new Pseudo[m_numPseudo];
     for (int i = 0; i < m_numPseudo; i++)
     {
         m_pseudos[i].uid = be::read<uint32>(p);
         m_pseudos[i].gid = be::read<uint16>(p);
     }
     const size_t clen = readClassMap(p, passes_start - p, version, e);
     if (e || e.test(p + clen > passes_start, E_BADPASSESSTART)) { releaseBuffers(); return face.error(e); }
     m_passes = new Pass[m_numPasses];
     for (size_t i = 0; i < m_numPasses; ++i)
     {
         const byte * const pass_start = silf_start + be::read<uint32>(o_passes),
                    * const pass_end = silf_start + be::peek<uint32>(o_passes);
         face.error_context((face.error_context() & 0xFF00) + EC_ASILF + (i << 16));
         if (e.test(pass_start > pass_end, E_BADPASSSTART) || e.test(pass_end > silf_end, E_BADPASSEND)) {
             releaseBuffers(); return face.error(e);
         }
         m_passes[i].init(this);
         if (!m_passes[i].readPass(pass_start, pass_end - pass_start, pass_start - silf_start, face, e))
         {
             releaseBuffers();
             return false;
         }
     }
     // fill in gr_faceinfo
     m_silfinfo.upem = face.glyphs().unitsPerEm();
     m_silfinfo.has_bidi_pass = (m_bPass != 0xFF);
     m_silfinfo.justifies = (m_numJusts != 0) || (m_jPass < m_pPass);
     m_silfinfo.line_ends = (m_flags & 1);
     m_silfinfo.space_contextuals = gr_faceinfo::gr_space_contextuals((m_flags >> 2) & 0x7);
     return true;
 }
 template<typename T> inline uint32 Silf::readClassOffsets(const byte *&p, size_t data_len, Error &e)
 {
     const T cls_off = 2*sizeof(uint16) + sizeof(T)*(m_nClass+1);
     const size_t max_off = (be::peek<T>(p + sizeof(T)*m_nClass) - cls_off)/sizeof(uint16);
     // Check that the last+1 offset is less than or equal to the class map length.
     if (e.test(be::peek<T>(p) != cls_off, E_MISALIGNEDCLASSES)
             || e.test(max_off > (data_len - cls_off)/sizeof(uint16), E_HIGHCLASSOFFSET))
         return ERROROFFSET;
     // Read in all the offsets.
     m_classOffsets = gralloc<uint32>(m_nClass+1);
     if (e.test(!m_classOffsets, E_OUTOFMEM)) return ERROROFFSET;
     for (uint32 * o = m_classOffsets, * const o_end = o + m_nClass + 1; o != o_end; ++o)
     {
         *o = (be::read<T>(p) - cls_off)/sizeof(uint16);
         if (e.test(*o > max_off, E_HIGHCLASSOFFSET))
             return ERROROFFSET;
     }
     return max_off;
 }
 size_t Silf::readClassMap(const byte *p, size_t data_len, uint32 version, Error &e)
 {
     if (e.test(data_len < sizeof(uint16)*2, E_BADCLASSSIZE)) return ERROROFFSET;
     m_nClass  = be::read<uint16>(p);
     m_nLinear = be::read<uint16>(p);
     // Check that numLinear < numClass,
     // that there is at least enough data for numClasses offsets.
     if (e.test(m_nLinear > m_nClass, E_TOOMANYLINEAR)
      || e.test((m_nClass + 1) * (version >= 0x00040000 ? sizeof(uint32) : sizeof(uint16)) > (data_len - 4), E_CLASSESTOOBIG))
         return ERROROFFSET;
     uint32 max_off;
     if (version >= 0x00040000)
         max_off = readClassOffsets<uint32>(p, data_len, e);
     else
         max_off = readClassOffsets<uint16>(p, data_len, e);
     if (max_off == ERROROFFSET) return ERROROFFSET;
     // Check the linear offsets are sane, these must be monotonically increasing.
     for (const uint32 *o = m_classOffsets, * const o_end = o + m_nLinear; o != o_end; ++o)
         if (e.test(o[0] > o[1], E_BADCLASSOFFSET))
             return ERROROFFSET;
     // Fortunately the class data is all uint16s so we can decode these now
     m_classData = gralloc<uint16>(max_off);
     if (e.test(!m_classData, E_OUTOFMEM)) return ERROROFFSET;
     for (uint16 *d = m_classData, * const d_end = d + max_off; d != d_end; ++d)
         *d = be::read<uint16>(p);
     // Check the lookup class invariants for each non-linear class
     for (const uint32 *o = m_classOffsets + m_nLinear, * const o_end = m_classOffsets + m_nClass; o != o_end; ++o)
     {
         const uint16 * lookup = m_classData + *o;
         if (e.test(*o > max_off - 4, E_HIGHCLASSOFFSET)                        // LookupClass doesn't stretch over max_off
          || e.test(lookup[0] == 0                                                   // A LookupClass with no looks is a suspicious thing ...
                     || lookup[0] > (max_off - *o - 4)/2                             // numIDs lookup pairs fits within (start of LookupClass' lookups array, max_off]
                     || lookup[3] != lookup[0] - lookup[1], E_BADCLASSLOOKUPINFO))   // rangeShift:   numIDs  - searchRange
             return ERROROFFSET;
     }
     return max_off;
 }
 uint16 Silf::findPseudo(uint32 uid) const
 {
     for (int i = 0; i < m_numPseudo; i++)
         if (m_pseudos[i].uid == uid) return m_pseudos[i].gid;
     return 0;
 }
 uint16 Silf::findClassIndex(uint16 cid, uint16 gid) const
 {
     if (cid > m_nClass) return -1;
     const uint16 * cls = m_classData + m_classOffsets[cid];
     if (cid < m_nLinear)        // output class being used for input, shouldn't happen
     {
         for (unsigned int i = 0, n = m_classOffsets[cid + 1]; i < n; ++i, ++cls)
             if (*cls == gid) return i;
         return -1;
     }
     else
     {
         const uint16 *  min = cls + 4,      // lookups array
                      *  max = min + cls[0]*2; // lookups aray is numIDs (cls[0]) uint16 pairs long
         do
         {
             const uint16 * p = min + (-2 & ((max-min)/2));
             if  (p[0] > gid)    max = p;
             else                min = p;
         }
         while (max - min > 2);
         return min[0] == gid ? min[1] : -1;
     }
 }
 uint16 Silf::getClassGlyph(uint16 cid, unsigned int index) const
 {
     if (cid > m_nClass) return 0;
     uint32 loc = m_classOffsets[cid];
     if (cid < m_nLinear)
     {
         if (index < m_classOffsets[cid + 1] - loc)
             return m_classData[index + loc];
     }
     else        // input class being used for output. Shouldn't happen
     {
         for (unsigned int i = loc + 4; i < m_classOffsets[cid + 1]; i += 2)
             if (m_classData[i + 1] == index) return m_classData[i];
     }
     return 0;
 }
 bool Silf::runGraphite(Segment *seg, uint8 firstPass, uint8 lastPass, int dobidi) const
 {
     assert(seg != 0);
     SlotMap            map(*seg);
     FiniteStateMachine fsm(map, seg->getFace()->logger());
     vm::Machine        m(map);
     unsigned int       initSize = seg->slotCount();
     uint8              lbidi = m_bPass;
 #if !defined GRAPHITE2_NTRACING
     json * const dbgout = seg->getFace()->logger();
 #endif
     if (lastPass == 0)
     {
         if (firstPass == lastPass && lbidi == 0xFF)
             return true;
         lastPass = m_numPasses;
     }
     if (firstPass <= lbidi && lastPass >= lbidi && dobidi)
         lastPass++;
     else
         lbidi = 0xFF;
     for (size_t i = firstPass; i < lastPass; ++i)
     {
         // bidi and mirroring
         if (i == lbidi)
         {
 #if !defined GRAPHITE2_NTRACING
             if (dbgout)
             {
                 *dbgout << json::item << json::object
                             << "id"     << -1
                             << "slots"  << json::array;
                 seg->positionSlots(0);
                 for(Slot * s = seg->first(); s; s = s->next())
                     *dbgout     << dslot(seg, s);
                 *dbgout         << json::close
                             << "rules"  << json::array << json::close
                             << json::close;
             }
 #endif
             if (!(seg->dir() & 2))
                 seg->bidiPass(m_aBidi, seg->dir() & 1, m_aMirror);
             else if (m_aMirror)
             {
                 Slot * s;
                 for (s = seg->first(); s; s = s->next())
                 {
                     unsigned short g = seg->glyphAttr(s->gid(), m_aMirror);
                     if (g && (!(seg->dir() & 4) || !seg->glyphAttr(s->gid(), m_aMirror + 1)))
                         s->setGlyph(seg, g);
                 }
             }
         --i;
         --lastPass;
         lbidi = 0xFF;
         continue;
         }
 #if !defined GRAPHITE2_NTRACING
         if (dbgout)
         {
             *dbgout << json::item << json::object
                         << "id"     << i+1
                         << "slots"  << json::array;
             seg->positionSlots(0);
             for(Slot * s = seg->first(); s; s = s->next())
                 *dbgout     << dslot(seg, s);
             *dbgout         << json::close;
         }
 #endif
         // test whether to reorder, prepare for positioning
         if (i >= 32 || (seg->passBits() & (1 << i)) == 0)
             m_passes[i].runGraphite(m, fsm);
         // only subsitution passes can change segment length, cached subsegments are short for their text
         if (m.status() != vm::Machine::finished
             || (i < m_pPass && (seg->slotCount() > initSize * MAX_SEG_GROWTH_FACTOR
             || (seg->slotCount() && seg->slotCount() * MAX_SEG_GROWTH_FACTOR < initSize))))
             return false;
     }
     return true;
 }

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gfx/graphite2/src/Silf.cpp@b8a032363ba2 (annotated)

gfx/graphite2/src/Silf.cpp