The Tor Browser: comparison gfx/ots/src/cmap.cc

--1:000000000000
+:ac8c77bf3a1a
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#include "cmap.h"
+#include <algorithm>
+#include <set>
+#include <utility>
+#include <vector>
+#include "maxp.h"
+#include "os2.h"
+// cmap - Character To Glyph Index Mapping Table
+// http://www.microsoft.com/typography/otspec/cmap.htm
+#define TABLE_NAME "cmap"
+namespace {
+struct CMAPSubtableHeader {
+uint16_t platform;
+uint16_t encoding;
+uint32_t offset;
+uint16_t format;
+uint32_t length;
+uint32_t language;
+};
+struct Subtable314Range {
+uint16_t start_range;
+uint16_t end_range;
+int16_t id_delta;
+uint16_t id_range_offset;
+uint32_t id_range_offset_offset;
+};
+// The maximum number of groups in format 12, 13 or 14 subtables.
+// Note: 0xFFFF is the maximum number of glyphs in a single font file.
+const unsigned kMaxCMAPGroups = 0xFFFF;
+// Glyph array size for the Mac Roman (format 0) table.
+const size_t kFormat0ArraySize = 256;
+// The upper limit of the Unicode code point.
+const uint32_t kUnicodeUpperLimit = 0x10FFFF;
+// The maximum number of UVS records (See below).
+const uint32_t kMaxCMAPSelectorRecords = 259;
+// The range of UVSes are:
+//   0x180B-0x180D (3 code points)
+//   0xFE00-0xFE0F (16 code points)
+//   0xE0100-0xE01EF (240 code points)
+const uint32_t kMongolianVSStart = 0x180B;
+const uint32_t kMongolianVSEnd = 0x180D;
+const uint32_t kVSStart = 0xFE00;
+const uint32_t kVSEnd = 0xFE0F;
+const uint32_t kIVSStart = 0xE0100;
+const uint32_t kIVSEnd = 0xE01EF;
+const uint32_t kUVSUpperLimit = 0xFFFFFF;
+// Parses Format 4 tables
+bool ParseFormat4(ots::OpenTypeFile *file, int platform, int encoding,
+const uint8_t *data, size_t length, uint16_t num_glyphs) {
+ots::Buffer subtable(data, length);
+// 0.3.4, 3.0.4 or 3.1.4 subtables are complex and, rather than expanding the
+// whole thing and recompacting it, we validate it and include it verbatim
+// in the output.
+if (!file->os2) {
+return OTS_FAILURE_MSG("Required OS/2 table missing");
+}
+if (!subtable.Skip(4)) {
+return OTS_FAILURE_MSG("Can't read 4 bytes at start of cmap format 4 subtable");
+}
+uint16_t language = 0;
+if (!subtable.ReadU16(&language)) {
+return OTS_FAILURE_MSG("Can't read language");
+}
+if (language) {
+// Platform ID 3 (windows) subtables should have language '0'.
+return OTS_FAILURE_MSG("Languages should be 0 (%d)", language);
+}
+uint16_t segcountx2, search_range, entry_selector, range_shift;
+segcountx2 = search_range = entry_selector = range_shift = 0;
+if (!subtable.ReadU16(&segcountx2) ||
+!subtable.ReadU16(&search_range) ||
+!subtable.ReadU16(&entry_selector) ||
+!subtable.ReadU16(&range_shift)) {
+return OTS_FAILURE_MSG("Failed to read subcmap structure");
+}
+if (segcountx2 & 1 || search_range & 1) {
+return OTS_FAILURE_MSG("Bad subcmap structure");
+}
+const uint16_t segcount = segcountx2 >> 1;
+// There must be at least one segment according the spec.
+if (segcount < 1) {
+return OTS_FAILURE_MSG("Segcount < 1 (%d)", segcount);
+}
+// log2segcount is the maximal x s.t. 2^x < segcount
+unsigned log2segcount = 0;
+while (1u << (log2segcount + 1) <= segcount) {
+log2segcount++;
+}
+const uint16_t expected_search_range = 2 * 1u << log2segcount;
+if (expected_search_range != search_range) {
+return OTS_FAILURE_MSG("expected search range != search range (%d != %d)", expected_search_range, search_range);
+}
+if (entry_selector != log2segcount) {
+return OTS_FAILURE_MSG("entry selector != log2(segement count) (%d != %d)", entry_selector, log2segcount);
+}
+const uint16_t expected_range_shift = segcountx2 - search_range;
+if (range_shift != expected_range_shift) {
+return OTS_FAILURE_MSG("unexpected range shift (%d != %d)", range_shift, expected_range_shift);
+}
+std::vector<Subtable314Range> ranges(segcount);
+for (unsigned i = 0; i < segcount; ++i) {
+if (!subtable.ReadU16(&ranges[i].end_range)) {
+return OTS_FAILURE_MSG("Failed to read segment %d", i);
+}
+}
+uint16_t padding;
+if (!subtable.ReadU16(&padding)) {
+return OTS_FAILURE_MSG("Failed to read cmap subtable segment padding");
+}
+if (padding) {
+return OTS_FAILURE_MSG("Non zero cmap subtable segment padding (%d)", padding);
+}
+for (unsigned i = 0; i < segcount; ++i) {
+if (!subtable.ReadU16(&ranges[i].start_range)) {
+return OTS_FAILURE_MSG("Failed to read segment start range %d", i);
+}
+}
+for (unsigned i = 0; i < segcount; ++i) {
+if (!subtable.ReadS16(&ranges[i].id_delta)) {
+return OTS_FAILURE_MSG("Failed to read segment delta %d", i);
+}
+}
+for (unsigned i = 0; i < segcount; ++i) {
+ranges[i].id_range_offset_offset = subtable.offset();
+if (!subtable.ReadU16(&ranges[i].id_range_offset)) {
+return OTS_FAILURE_MSG("Failed to read segment range offset %d", i);
+}
+if (ranges[i].id_range_offset & 1) {
+// Some font generators seem to put 65535 on id_range_offset
+// for 0xFFFF-0xFFFF range.
+// (e.g., many fonts in http://www.princexml.com/fonts/)
+if (i == segcount - 1u) {
+OTS_WARNING("bad id_range_offset");
+ranges[i].id_range_offset = 0;
+// The id_range_offset value in the transcoded font will not change
+// since this table is not actually "transcoded" yet.
+} else {
+return OTS_FAILURE_MSG("Bad segment offset (%d)", ranges[i].id_range_offset);
+}
+}
+}
+// ranges must be ascending order, based on the end_code. Ranges may not
+// overlap.
+for (unsigned i = 1; i < segcount; ++i) {
+if ((i == segcount - 1u) &&
+(ranges[i - 1].start_range == 0xffff) &&
+(ranges[i - 1].end_range == 0xffff) &&
+(ranges[i].start_range == 0xffff) &&
+(ranges[i].end_range == 0xffff)) {
+// Some fonts (e.g., Germania.ttf) have multiple 0xffff terminators.
+// We'll accept them as an exception.
+OTS_WARNING("multiple 0xffff terminators found");
+continue;
+}
+// Note: some Linux fonts (e.g., LucidaSansOblique.ttf, bsmi00lp.ttf) have
+// unsorted table...
+if (ranges[i].end_range <= ranges[i - 1].end_range) {
+return OTS_FAILURE_MSG("Out of order end range (%d <= %d)", ranges[i].end_range, ranges[i-1].end_range);
+}
+if (ranges[i].start_range <= ranges[i - 1].end_range) {
+return OTS_FAILURE_MSG("out of order start range (%d <= %d)", ranges[i].start_range, ranges[i-1].end_range);
+}
+// On many fonts, the value of {first, last}_char_index are incorrect.
+// Fix them.
+if (file->os2->first_char_index != 0xFFFF &&
+ranges[i].start_range != 0xFFFF &&
+file->os2->first_char_index > ranges[i].start_range) {
+file->os2->first_char_index = ranges[i].start_range;
+}
+if (file->os2->last_char_index != 0xFFFF &&
+ranges[i].end_range != 0xFFFF &&
+file->os2->last_char_index < ranges[i].end_range) {
+file->os2->last_char_index = ranges[i].end_range;
+}
+}
+// The last range must end at 0xffff
+if (ranges[segcount - 1].start_range != 0xffff || ranges[segcount - 1].end_range != 0xffff) {
+return OTS_FAILURE_MSG("Final segment start and end must be 0xFFFF (0x%04X-0x%04X)",
+ranges[segcount - 1].start_range, ranges[segcount - 1].end_range);
+}
+// A format 4 CMAP subtable is complex. To be safe we simulate a lookup of
+// each code-point defined in the table and make sure that they are all valid
+// glyphs and that we don't access anything out-of-bounds.
+for (unsigned i = 0; i < segcount; ++i) {
+for (unsigned cp = ranges[i].start_range; cp <= ranges[i].end_range; ++cp) {
+const uint16_t code_point = cp;
+if (ranges[i].id_range_offset == 0) {
+// this is explictly allowed to overflow in the spec
+const uint16_t glyph = code_point + ranges[i].id_delta;
+if (glyph >= num_glyphs) {
+return OTS_FAILURE_MSG("Range glyph reference too high (%d > %d)", glyph, num_glyphs - 1);
+}
+} else {
+const uint16_t range_delta = code_point - ranges[i].start_range;
+// this might seem odd, but it's true. The offset is relative to the
+// location of the offset value itself.
+const uint32_t glyph_id_offset = ranges[i].id_range_offset_offset +
+ranges[i].id_range_offset +
+range_delta * 2;
+// We need to be able to access a 16-bit value from this offset
+if (glyph_id_offset + 1 >= length) {
+return OTS_FAILURE_MSG("bad glyph id offset (%d > %ld)", glyph_id_offset, length);
+}
+uint16_t glyph;
+std::memcpy(&glyph, data + glyph_id_offset, 2);
+glyph = ntohs(glyph);
+if (glyph >= num_glyphs) {
+return OTS_FAILURE_MSG("Range glyph reference too high (%d > %d)", glyph, num_glyphs - 1);
+}
+}
+}
+}
+// We accept the table.
+// TODO(yusukes): transcode the subtable.
+if (platform == 3 && encoding == 0) {
+file->cmap->subtable_3_0_4_data = data;
+file->cmap->subtable_3_0_4_length = length;
+} else if (platform == 3 && encoding == 1) {
+file->cmap->subtable_3_1_4_data = data;
+file->cmap->subtable_3_1_4_length = length;
+} else if (platform == 0 && encoding == 3) {
+file->cmap->subtable_0_3_4_data = data;
+file->cmap->subtable_0_3_4_length = length;
+} else {
+return OTS_FAILURE_MSG("Unknown cmap subtable type (platform=%d, encoding=%d)", platform, encoding);
+}
+return true;
+}
+bool Parse31012(ots::OpenTypeFile *file,
+const uint8_t *data, size_t length, uint16_t num_glyphs) {
+ots::Buffer subtable(data, length);
+// Format 12 tables are simple. We parse these and fully serialise them
+// later.
+if (!subtable.Skip(8)) {
+return OTS_FAILURE_MSG("failed to skip the first 8 bytes of format 12 subtable");
+}
+uint32_t language = 0;
+if (!subtable.ReadU32(&language)) {
+return OTS_FAILURE_MSG("can't read format 12 subtable language");
+}
+if (language) {
+return OTS_FAILURE_MSG("format 12 subtable language should be zero (%d)", language);
+}
+uint32_t num_groups = 0;
+if (!subtable.ReadU32(&num_groups)) {
+return OTS_FAILURE_MSG("can't read number of format 12 subtable groups");
+}
+if (num_groups == 0 || num_groups > kMaxCMAPGroups) {
+return OTS_FAILURE_MSG("bad format 12 subtable group count %d", num_groups);
+}
+std::vector<ots::OpenTypeCMAPSubtableRange> &groups
+= file->cmap->subtable_3_10_12;
+groups.resize(num_groups);
+for (unsigned i = 0; i < num_groups; ++i) {
+if (!subtable.ReadU32(&groups[i].start_range) ||
+!subtable.ReadU32(&groups[i].end_range) ||
+!subtable.ReadU32(&groups[i].start_glyph_id)) {
+return OTS_FAILURE_MSG("can't read format 12 subtable group");
+}
+if (groups[i].start_range > kUnicodeUpperLimit ||
+groups[i].end_range > kUnicodeUpperLimit ||
+groups[i].start_glyph_id > 0xFFFF) {
+return OTS_FAILURE_MSG("bad format 12 subtable group (startCharCode=0x%4X, endCharCode=0x%4X, startGlyphID=%d)",
+groups[i].start_range, groups[i].end_range, groups[i].start_glyph_id);
+}
+// [0xD800, 0xDFFF] are surrogate code points.
+if (groups[i].start_range >= 0xD800 &&
+groups[i].start_range <= 0xDFFF) {
+return OTS_FAILURE_MSG("format 12 subtable out of range group startCharCode (0x%4X)", groups[i].start_range);
+}
+if (groups[i].end_range >= 0xD800 &&
+groups[i].end_range <= 0xDFFF) {
+return OTS_FAILURE_MSG("format 12 subtable out of range group endCharCode (0x%4X)", groups[i].end_range);
+}
+if (groups[i].start_range < 0xD800 &&
+groups[i].end_range > 0xDFFF) {
+return OTS_FAILURE_MSG("bad format 12 subtable group startCharCode (0x%4X) or endCharCode (0x%4X)",
+groups[i].start_range, groups[i].end_range);
+}
+// We assert that the glyph value is within range. Because of the range
+// limits, above, we don't need to worry about overflow.
+if (groups[i].end_range < groups[i].start_range) {
+return OTS_FAILURE_MSG("format 12 subtable group endCharCode before startCharCode (0x%4X < 0x%4X)",
+groups[i].end_range, groups[i].start_range);
+}
+if ((groups[i].end_range - groups[i].start_range) +
+groups[i].start_glyph_id > num_glyphs) {
+return OTS_FAILURE_MSG("bad format 12 subtable group startGlyphID (%d)", groups[i].start_glyph_id);
+}
+}
+// the groups must be sorted by start code and may not overlap
+for (unsigned i = 1; i < num_groups; ++i) {
+if (groups[i].start_range <= groups[i - 1].start_range) {
+return OTS_FAILURE_MSG("out of order format 12 subtable group (startCharCode=0x%4X <= startCharCode=0x%4X of previous group)",
+groups[i].start_range, groups[i-1].start_range);
+}
+if (groups[i].start_range <= groups[i - 1].end_range) {
+return OTS_FAILURE_MSG("overlapping format 12 subtable groups (startCharCode=0x%4X <= endCharCode=0x%4X of previous group)",
+groups[i].start_range, groups[i-1].end_range);
+}
+}
+return true;
+}
+bool Parse31013(ots::OpenTypeFile *file,
+const uint8_t *data, size_t length, uint16_t num_glyphs) {
+ots::Buffer subtable(data, length);
+// Format 13 tables are simple. We parse these and fully serialise them
+// later.
+if (!subtable.Skip(8)) {
+return OTS_FAILURE_MSG("Bad cmap subtable length");
+}
+uint16_t language = 0;
+if (!subtable.ReadU16(&language)) {
+return OTS_FAILURE_MSG("Can't read cmap subtable language");
+}
+if (language) {
+return OTS_FAILURE_MSG("Cmap subtable language should be zero but is %d", language);
+}
+uint32_t num_groups = 0;
+if (!subtable.ReadU32(&num_groups)) {
+return OTS_FAILURE_MSG("Can't read number of groups in a cmap subtable");
+}
+// We limit the number of groups in the same way as in 3.10.12 tables. See
+// the comment there in
+if (num_groups == 0 || num_groups > kMaxCMAPGroups) {
+return OTS_FAILURE_MSG("Bad number of groups (%d) in a cmap subtable", num_groups);
+}
+std::vector<ots::OpenTypeCMAPSubtableRange> &groups
+= file->cmap->subtable_3_10_13;
+groups.resize(num_groups);
+for (unsigned i = 0; i < num_groups; ++i) {
+if (!subtable.ReadU32(&groups[i].start_range) ||
+!subtable.ReadU32(&groups[i].end_range) ||
+!subtable.ReadU32(&groups[i].start_glyph_id)) {
+return OTS_FAILURE_MSG("Can't read subrange structure in a cmap subtable");
+}
+// We conservatively limit all of the values to protect some parsers from
+// overflows
+if (groups[i].start_range > kUnicodeUpperLimit ||
+groups[i].end_range > kUnicodeUpperLimit ||
+groups[i].start_glyph_id > 0xFFFF) {
+return OTS_FAILURE_MSG("Bad subrange with start_range=%d, end_range=%d, start_glyph_id=%d", groups[i].start_range, groups[i].end_range, groups[i].start_glyph_id);
+}
+if (groups[i].start_glyph_id >= num_glyphs) {
+return OTS_FAILURE_MSG("Subrange starting glyph id too high (%d > %d)", groups[i].start_glyph_id, num_glyphs);
+}
+}
+// the groups must be sorted by start code and may not overlap
+for (unsigned i = 1; i < num_groups; ++i) {
+if (groups[i].start_range <= groups[i - 1].start_range) {
+return OTS_FAILURE_MSG("Overlapping subrange starts (%d >= %d)", groups[i]. start_range, groups[i-1].start_range);
+}
+if (groups[i].start_range <= groups[i - 1].end_range) {
+return OTS_FAILURE_MSG("Overlapping subranges (%d <= %d)", groups[i].start_range, groups[i-1].end_range);
+}
+}
+return true;
+}
+bool Parse0514(ots::OpenTypeFile *file,
+const uint8_t *data, size_t length, uint16_t num_glyphs) {
+// Unicode Variation Selector table
+ots::Buffer subtable(data, length);
+// Format 14 tables are simple. We parse these and fully serialise them
+// later.
+// Skip format (USHORT) and length (ULONG)
+if (!subtable.Skip(6)) {
+return OTS_FAILURE_MSG("Can't read start of cmap subtable");
+}
+uint32_t num_records = 0;
+if (!subtable.ReadU32(&num_records)) {
+return OTS_FAILURE_MSG("Can't read number of records in cmap subtable");
+}
+if (num_records == 0 || num_records > kMaxCMAPSelectorRecords) {
+return OTS_FAILURE_MSG("Bad number of records (%d) in cmap subtable", num_records);
+}
+std::vector<ots::OpenTypeCMAPSubtableVSRecord>& records
+= file->cmap->subtable_0_5_14;
+records.resize(num_records);
+for (unsigned i = 0; i < num_records; ++i) {
+if (!subtable.ReadU24(&records[i].var_selector) ||
+!subtable.ReadU32(&records[i].default_offset) ||
+!subtable.ReadU32(&records[i].non_default_offset)) {
+return OTS_FAILURE_MSG("Can't read record structure of record %d in cmap subtale", i);
+}
+// Checks the value of variation selector
+if (!((records[i].var_selector >= kMongolianVSStart &&
+records[i].var_selector <= kMongolianVSEnd) ||
+(records[i].var_selector >= kVSStart &&
+records[i].var_selector <= kVSEnd) ||
+(records[i].var_selector >= kIVSStart &&
+records[i].var_selector <= kIVSEnd))) {
+return OTS_FAILURE_MSG("Bad record variation selector (%04X) in record %i", records[i].var_selector, i);
+}
+if (i > 0 &&
+records[i-1].var_selector >= records[i].var_selector) {
+return OTS_FAILURE_MSG("Out of order variation selector (%04X >= %04X) in record %d", records[i-1].var_selector, records[i].var_selector, i);
+}
+// Checks offsets
+if (!records[i].default_offset && !records[i].non_default_offset) {
+return OTS_FAILURE_MSG("No default aoffset in variation selector record %d", i);
+}
+if (records[i].default_offset &&
+records[i].default_offset >= length) {
+return OTS_FAILURE_MSG("Default offset too high (%d >= %ld) in record %d", records[i].default_offset, length, i);
+}
+if (records[i].non_default_offset &&
+records[i].non_default_offset >= length) {
+return OTS_FAILURE_MSG("Non default offset too high (%d >= %ld) in record %d", records[i].non_default_offset, length, i);
+}
+}
+for (unsigned i = 0; i < num_records; ++i) {
+// Checks default UVS table
+if (records[i].default_offset) {
+subtable.set_offset(records[i].default_offset);
+uint32_t num_ranges = 0;
+if (!subtable.ReadU32(&num_ranges)) {
+return OTS_FAILURE_MSG("Can't read number of ranges in record %d", i);
+}
+if (!num_ranges || num_ranges > kMaxCMAPGroups) {
+return OTS_FAILURE_MSG("number of ranges too high (%d > %d) in record %d", num_ranges, kMaxCMAPGroups, i);
+}
+uint32_t last_unicode_value = 0;
+std::vector<ots::OpenTypeCMAPSubtableVSRange>& ranges
+= records[i].ranges;
+ranges.resize(num_ranges);
+for (unsigned j = 0; j < num_ranges; ++j) {
+if (!subtable.ReadU24(&ranges[j].unicode_value) ||
+!subtable.ReadU8(&ranges[j].additional_count)) {
+return OTS_FAILURE_MSG("Can't read range info in variation selector record %d", i);
+}
+const uint32_t check_value =
+ranges[j].unicode_value + ranges[j].additional_count;
+if (ranges[j].unicode_value == 0 ||
+ranges[j].unicode_value > kUnicodeUpperLimit ||
+check_value > kUVSUpperLimit ||
+(last_unicode_value &&
+ranges[j].unicode_value <= last_unicode_value)) {
+return OTS_FAILURE_MSG("Bad Unicode value *%04X) in variation selector range %d record %d", ranges[j].unicode_value, j, i);
+}
+last_unicode_value = check_value;
+}
+}
+// Checks non default UVS table
+if (records[i].non_default_offset) {
+subtable.set_offset(records[i].non_default_offset);
+uint32_t num_mappings = 0;
+if (!subtable.ReadU32(&num_mappings)) {
+return OTS_FAILURE_MSG("Can't read number of mappings in variation selector record %d", i);
+}
+if (!num_mappings || num_mappings > kMaxCMAPGroups) {
+return OTS_FAILURE_MSG("Number of mappings too high (%d) in variation selector record %d", num_mappings, i);
+}
+uint32_t last_unicode_value = 0;
+std::vector<ots::OpenTypeCMAPSubtableVSMapping>& mappings
+= records[i].mappings;
+mappings.resize(num_mappings);
+for (unsigned j = 0; j < num_mappings; ++j) {
+if (!subtable.ReadU24(&mappings[j].unicode_value) ||
+!subtable.ReadU16(&mappings[j].glyph_id)) {
+return OTS_FAILURE_MSG("Can't read mapping %d in variation selector record %d", j, i);
+}
+if (mappings[j].glyph_id == 0 ||
+mappings[j].unicode_value == 0 ||
+mappings[j].unicode_value > kUnicodeUpperLimit ||
+(last_unicode_value &&
+mappings[j].unicode_value <= last_unicode_value)) {
+return OTS_FAILURE_MSG("Bad mapping (%04X -> %d) in mapping %d of variation selector %d", mappings[j].unicode_value, mappings[j].glyph_id, j, i);
+}
+last_unicode_value = mappings[j].unicode_value;
+}
+}
+}
+if (subtable.offset() != length) {
+return OTS_FAILURE_MSG("Bad subtable offset (%ld != %ld)", subtable.offset(), length);
+}
+file->cmap->subtable_0_5_14_length = subtable.offset();
+return true;
+}
+bool Parse100(ots::OpenTypeFile *file, const uint8_t *data, size_t length) {
+// Mac Roman table
+ots::Buffer subtable(data, length);
+if (!subtable.Skip(4)) {
+return OTS_FAILURE_MSG("Bad cmap subtable");
+}
+uint16_t language = 0;
+if (!subtable.ReadU16(&language)) {
+return OTS_FAILURE_MSG("Can't read language in cmap subtable");
+}
+if (language) {
+// simsun.ttf has non-zero language id.
+OTS_WARNING("language id should be zero: %u", language);
+}
+file->cmap->subtable_1_0_0.reserve(kFormat0ArraySize);
+for (size_t i = 0; i < kFormat0ArraySize; ++i) {
+uint8_t glyph_id = 0;
+if (!subtable.ReadU8(&glyph_id)) {
+return OTS_FAILURE_MSG("Can't read glyph id at array[%ld] in cmap subtable", i);
+}
+file->cmap->subtable_1_0_0.push_back(glyph_id);
+}
+return true;
+}
+}  // namespace
+namespace ots {
+bool ots_cmap_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
+Buffer table(data, length);
+file->cmap = new OpenTypeCMAP;
+uint16_t version = 0;
+uint16_t num_tables = 0;
+if (!table.ReadU16(&version) ||
+!table.ReadU16(&num_tables)) {
+return OTS_FAILURE_MSG("Can't read structure of cmap");
+}
+if (version != 0) {
+return OTS_FAILURE_MSG("Non zero cmap version (%d)", version);
+}
+if (!num_tables) {
+return OTS_FAILURE_MSG("No subtables in cmap!");
+}
+std::vector<CMAPSubtableHeader> subtable_headers;
+// read the subtable headers
+subtable_headers.reserve(num_tables);
+for (unsigned i = 0; i < num_tables; ++i) {
+CMAPSubtableHeader subt;
+if (!table.ReadU16(&subt.platform) ||
+!table.ReadU16(&subt.encoding) ||
+!table.ReadU32(&subt.offset)) {
+return OTS_FAILURE_MSG("Can't read subtable information cmap subtable %d", i);
+}
+subtable_headers.push_back(subt);
+}
+const size_t data_offset = table.offset();
+// make sure that all the offsets are valid.
+for (unsigned i = 0; i < num_tables; ++i) {
+if (subtable_headers[i].offset > 1024 * 1024 * 1024) {
+return OTS_FAILURE_MSG("Bad subtable offset in cmap subtable %d", i);
+}
+if (subtable_headers[i].offset < data_offset ||
+subtable_headers[i].offset >= length) {
+return OTS_FAILURE_MSG("Bad subtable offset (%d) in cmap subtable %d", subtable_headers[i].offset, i);
+}
+}
+// the format of the table is the first couple of bytes in the table. The
+// length of the table is stored in a format-specific way.
+for (unsigned i = 0; i < num_tables; ++i) {
+table.set_offset(subtable_headers[i].offset);
+if (!table.ReadU16(&subtable_headers[i].format)) {
+return OTS_FAILURE_MSG("Can't read cmap subtable header format %d", i);
+}
+uint16_t len = 0;
+uint16_t lang = 0;
+switch (subtable_headers[i].format) {
+case 0:
+case 4:
+if (!table.ReadU16(&len)) {
+return OTS_FAILURE_MSG("Can't read cmap subtable %d length", i);
+}
+if (!table.ReadU16(&lang)) {
+return OTS_FAILURE_MSG("Can't read cmap subtable %d language", i);
+}
+subtable_headers[i].length = len;
+subtable_headers[i].language = lang;
+break;
+case 12:
+case 13:
+if (!table.Skip(2)) {
+return OTS_FAILURE_MSG("Bad cmap subtable %d structure", i);
+}
+if (!table.ReadU32(&subtable_headers[i].length)) {
+return OTS_FAILURE_MSG("Can read cmap subtable %d length", i);
+}
+if (!table.ReadU32(&subtable_headers[i].language)) {
+return OTS_FAILURE_MSG("Can't read cmap subtable %d language", i);
+}
+break;
+case 14:
+if (!table.ReadU32(&subtable_headers[i].length)) {
+return OTS_FAILURE_MSG("Can't read cmap subtable %d length", i);
+}
+subtable_headers[i].language = 0;
+break;
+default:
+subtable_headers[i].length = 0;
+subtable_headers[i].language = 0;
+break;
+}
+}
+// check if the table is sorted first by platform ID, then by encoding ID.
+uint32_t last_id = 0;
+for (unsigned i = 0; i < num_tables; ++i) {
+uint32_t current_id
+= (subtable_headers[i].platform << 24)
++ (subtable_headers[i].encoding << 16)
++ subtable_headers[i].language;
+if ((i != 0) && (last_id >= current_id)) {
+return OTS_FAILURE_MSG("subtable %d with platform ID %d, encoding ID %d, language ID %d "
+"following subtable with platform ID %d, encoding ID %d, language ID %d",
+i,
+(uint8_t)(current_id >> 24), (uint8_t)(current_id >> 16), (uint8_t)(current_id),
+(uint8_t)(last_id >> 24), (uint8_t)(last_id >> 16), (uint8_t)(last_id));
+}
+last_id = current_id;
+}
+// Now, verify that all the lengths are sane
+for (unsigned i = 0; i < num_tables; ++i) {
+if (!subtable_headers[i].length) continue;
+if (subtable_headers[i].length > 1024 * 1024 * 1024) {
+return OTS_FAILURE_MSG("Bad cmap subtable %d length", i);
+}
+// We know that both the offset and length are < 1GB, so the following
+// addition doesn't overflow
+const uint32_t end_byte
+= subtable_headers[i].offset + subtable_headers[i].length;
+if (end_byte > length) {
+return OTS_FAILURE_MSG("Over long cmap subtable %d @ %d for %d", i, subtable_headers[i].offset, subtable_headers[i].length);
+}
+}
+// check that the cmap subtables are not overlapping.
+std::set<std::pair<uint32_t, uint32_t> > uniq_checker;
+std::vector<std::pair<uint32_t, uint8_t> > overlap_checker;
+for (unsigned i = 0; i < num_tables; ++i) {
+const uint32_t end_byte
+= subtable_headers[i].offset + subtable_headers[i].length;
+if (!uniq_checker.insert(std::make_pair(subtable_headers[i].offset,
+end_byte)).second) {
+// Sometimes Unicode table and MS table share exactly the same data.
+// We'll allow this.
+continue;
+}
+overlap_checker.push_back(
+std::make_pair(subtable_headers[i].offset,
+static_cast<uint8_t>(1) /* start */));
+overlap_checker.push_back(
+std::make_pair(end_byte, static_cast<uint8_t>(0) /* end */));
+}
+std::sort(overlap_checker.begin(), overlap_checker.end());
+int overlap_count = 0;
+for (unsigned i = 0; i < overlap_checker.size(); ++i) {
+overlap_count += (overlap_checker[i].second ? 1 : -1);
+if (overlap_count > 1) {
+return OTS_FAILURE_MSG("Excessive overlap count %d", overlap_count);
+}
+}
+// we grab the number of glyphs in the file from the maxp table to make sure
+// that the character map isn't referencing anything beyound this range.
+if (!file->maxp) {
+return OTS_FAILURE_MSG("No maxp table in font! Needed by cmap.");
+}
+const uint16_t num_glyphs = file->maxp->num_glyphs;
+// We only support a subset of the possible character map tables. Microsoft
+// 'strongly recommends' that everyone supports the Unicode BMP table with
+// the UCS-4 table for non-BMP glyphs. We'll pass the following subtables:
+//   Platform ID   Encoding ID  Format
+//   0             0            4       (Unicode Default)
+//   0             3            4       (Unicode BMP)
+//   0             3            12      (Unicode UCS-4)
+//   0             5            14      (Unicode Variation Sequences)
+//   1             0            0       (Mac Roman)
+//   3             0            4       (MS Symbol)
+//   3             1            4       (MS Unicode BMP)
+//   3             10           12      (MS Unicode UCS-4)
+//   3             10           13      (MS UCS-4 Fallback mapping)
+//
+// Note:
+//  * 0-0-4 table is (usually) written as a 3-1-4 table. If 3-1-4 table
+//    also exists, the 0-0-4 table is ignored.
+//  * Unlike 0-0-4 table, 0-3-4 table is written as a 0-3-4 table.
+//    Some fonts which include 0-5-14 table seems to be required 0-3-4
+//    table. The 0-3-4 table will be wriiten even if 3-1-4 table also exists.
+//  * 0-3-12 table is written as a 3-10-12 table. If 3-10-12 table also
+//    exists, the 0-3-12 table is ignored.
+//
+for (unsigned i = 0; i < num_tables; ++i) {
+if (subtable_headers[i].platform == 0) {
+// Unicode platform
+if ((subtable_headers[i].encoding == 0) &&
+(subtable_headers[i].format == 4)) {
+// parse and output the 0-0-4 table as 3-1-4 table. Sometimes the 0-0-4
+// table actually points to MS symbol data and thus should be parsed as
+// 3-0-4 table (e.g., marqueem.ttf and quixotic.ttf). This error will be
+// recovered in ots_cmap_serialise().
+if (!ParseFormat4(file, 3, 1, data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE_MSG("Failed to parse format 4 cmap subtable %d", i);
+}
+} else if ((subtable_headers[i].encoding == 3) &&
+(subtable_headers[i].format == 4)) {
+// parse and output the 0-3-4 table as 0-3-4 table.
+if (!ParseFormat4(file, 0, 3, data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE_MSG("Failed to parse format 4 cmap subtable %d", i);
+}
+} else if ((subtable_headers[i].encoding == 3) &&
+(subtable_headers[i].format == 12)) {
+// parse and output the 0-3-12 table as 3-10-12 table.
+if (!Parse31012(file, data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE_MSG("Failed to parse format 12 cmap subtable %d", i);
+}
+} else if ((subtable_headers[i].encoding == 5) &&
+(subtable_headers[i].format == 14)) {
+if (!Parse0514(file, data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE_MSG("Failed to parse format 14 cmap subtable %d", i);
+}
+}
+} else if (subtable_headers[i].platform == 1) {
+// Mac platform
+if ((subtable_headers[i].encoding == 0) &&
+(subtable_headers[i].format == 0)) {
+// parse and output the 1-0-0 table.
+if (!Parse100(file, data + subtable_headers[i].offset,
+subtable_headers[i].length)) {
+return OTS_FAILURE();
+}
+}
+} else if (subtable_headers[i].platform == 3) {
+// MS platform
+switch (subtable_headers[i].encoding) {
+case 0:
+case 1:
+if (subtable_headers[i].format == 4) {
+// parse 3-0-4 or 3-1-4 table.
+if (!ParseFormat4(file, subtable_headers[i].platform,
+subtable_headers[i].encoding,
+data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE();
+}
+}
+break;
+case 10:
+if (subtable_headers[i].format == 12) {
+file->cmap->subtable_3_10_12.clear();
+if (!Parse31012(file, data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE();
+}
+} else if (subtable_headers[i].format == 13) {
+file->cmap->subtable_3_10_13.clear();
+if (!Parse31013(file, data + subtable_headers[i].offset,
+subtable_headers[i].length, num_glyphs)) {
+return OTS_FAILURE();
+}
+}
+break;
+}
+}
+}
+return true;
+}
+bool ots_cmap_should_serialise(OpenTypeFile *file) {
+return file->cmap != NULL;
+}
+bool ots_cmap_serialise(OTSStream *out, OpenTypeFile *file) {
+const bool have_034 = file->cmap->subtable_0_3_4_data != NULL;
+const bool have_0514 = file->cmap->subtable_0_5_14.size() != 0;
+const bool have_100 = file->cmap->subtable_1_0_0.size() != 0;
+const bool have_304 = file->cmap->subtable_3_0_4_data != NULL;
+// MS Symbol and MS Unicode tables should not co-exist.
+// See the comment above in 0-0-4 parser.
+const bool have_314 = (!have_304) && file->cmap->subtable_3_1_4_data;
+const bool have_31012 = file->cmap->subtable_3_10_12.size() != 0;
+const bool have_31013 = file->cmap->subtable_3_10_13.size() != 0;
+const unsigned num_subtables = static_cast<unsigned>(have_034) +
+static_cast<unsigned>(have_0514) +
+static_cast<unsigned>(have_100) +
+static_cast<unsigned>(have_304) +
+static_cast<unsigned>(have_314) +
+static_cast<unsigned>(have_31012) +
+static_cast<unsigned>(have_31013);
+const off_t table_start = out->Tell();
+// Some fonts don't have 3-0-4 MS Symbol nor 3-1-4 Unicode BMP tables
+// (e.g., old fonts for Mac). We don't support them.
+if (!have_304 && !have_314 && !have_034) {
+return OTS_FAILURE();
+}
+if (!out->WriteU16(0) ||
+!out->WriteU16(num_subtables)) {
+return OTS_FAILURE();
+}
+const off_t record_offset = out->Tell();
+if (!out->Pad(num_subtables * 8)) {
+return OTS_FAILURE();
+}
+const off_t offset_034 = out->Tell();
+if (have_034) {
+if (!out->Write(file->cmap->subtable_0_3_4_data,
+file->cmap->subtable_0_3_4_length)) {
+return OTS_FAILURE();
+}
+}
+const off_t offset_0514 = out->Tell();
+if (have_0514) {
+const std::vector<ots::OpenTypeCMAPSubtableVSRecord> &records
+= file->cmap->subtable_0_5_14;
+const unsigned num_records = records.size();
+if (!out->WriteU16(14) ||
+!out->WriteU32(file->cmap->subtable_0_5_14_length) ||
+!out->WriteU32(num_records)) {
+return OTS_FAILURE();
+}
+for (unsigned i = 0; i < num_records; ++i) {
+if (!out->WriteU24(records[i].var_selector) ||
+!out->WriteU32(records[i].default_offset) ||
+!out->WriteU32(records[i].non_default_offset)) {
+return OTS_FAILURE();
+}
+}
+for (unsigned i = 0; i < num_records; ++i) {
+if (records[i].default_offset) {
+const std::vector<ots::OpenTypeCMAPSubtableVSRange> &ranges
+= records[i].ranges;
+const unsigned num_ranges = ranges.size();
+if (!out->Seek(records[i].default_offset + offset_0514) ||
+!out->WriteU32(num_ranges)) {
+return OTS_FAILURE();
+}
+for (unsigned j = 0; j < num_ranges; ++j) {
+if (!out->WriteU24(ranges[j].unicode_value) ||
+!out->WriteU8(ranges[j].additional_count)) {
+return OTS_FAILURE();
+}
+}
+}
+if (records[i].non_default_offset) {
+const std::vector<ots::OpenTypeCMAPSubtableVSMapping> &mappings
+= records[i].mappings;
+const unsigned num_mappings = mappings.size();
+if (!out->Seek(records[i].non_default_offset + offset_0514) ||
+!out->WriteU32(num_mappings)) {
+return OTS_FAILURE();
+}
+for (unsigned j = 0; j < num_mappings; ++j) {
+if (!out->WriteU24(mappings[j].unicode_value) ||
+!out->WriteU16(mappings[j].glyph_id)) {
+return OTS_FAILURE();
+}
+}
+}
+}
+}
+const off_t offset_100 = out->Tell();
+if (have_100) {
+if (!out->WriteU16(0) ||  // format
+!out->WriteU16(6 + kFormat0ArraySize) ||  // length
+!out->WriteU16(0)) {  // language
+return OTS_FAILURE();
+}
+if (!out->Write(&(file->cmap->subtable_1_0_0[0]), kFormat0ArraySize)) {
+return OTS_FAILURE();
+}
+}
+const off_t offset_304 = out->Tell();
+if (have_304) {
+if (!out->Write(file->cmap->subtable_3_0_4_data,
+file->cmap->subtable_3_0_4_length)) {
+return OTS_FAILURE();
+}
+}
+const off_t offset_314 = out->Tell();
+if (have_314) {
+if (!out->Write(file->cmap->subtable_3_1_4_data,
+file->cmap->subtable_3_1_4_length)) {
+return OTS_FAILURE();
+}
+}
+const off_t offset_31012 = out->Tell();
+if (have_31012) {
+std::vector<OpenTypeCMAPSubtableRange> &groups
+= file->cmap->subtable_3_10_12;
+const unsigned num_groups = groups.size();
+if (!out->WriteU16(12) ||
+!out->WriteU16(0) ||
+!out->WriteU32(num_groups * 12 + 16) ||
+!out->WriteU32(0) ||
+!out->WriteU32(num_groups)) {
+return OTS_FAILURE();
+}
+for (unsigned i = 0; i < num_groups; ++i) {
+if (!out->WriteU32(groups[i].start_range) ||
+!out->WriteU32(groups[i].end_range) ||
+!out->WriteU32(groups[i].start_glyph_id)) {
+return OTS_FAILURE();
+}
+}
+}
+const off_t offset_31013 = out->Tell();
+if (have_31013) {
+std::vector<OpenTypeCMAPSubtableRange> &groups
+= file->cmap->subtable_3_10_13;
+const unsigned num_groups = groups.size();
+if (!out->WriteU16(13) ||
+!out->WriteU16(0) ||
+!out->WriteU32(num_groups * 12 + 14) ||
+!out->WriteU32(0) ||
+!out->WriteU32(num_groups)) {
+return OTS_FAILURE();
+}
+for (unsigned i = 0; i < num_groups; ++i) {
+if (!out->WriteU32(groups[i].start_range) ||
+!out->WriteU32(groups[i].end_range) ||
+!out->WriteU32(groups[i].start_glyph_id)) {
+return OTS_FAILURE();
+}
+}
+}
+const off_t table_end = out->Tell();
+// We might have hanging bytes from the above's checksum which the OTSStream
+// then merges into the table of offsets.
+OTSStream::ChecksumState saved_checksum = out->SaveChecksumState();
+out->ResetChecksum();
+// Now seek back and write the table of offsets
+if (!out->Seek(record_offset)) {
+return OTS_FAILURE();
+}
+if (have_034) {
+if (!out->WriteU16(0) ||
+!out->WriteU16(3) ||
+!out->WriteU32(offset_034 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (have_0514) {
+if (!out->WriteU16(0) ||
+!out->WriteU16(5) ||
+!out->WriteU32(offset_0514 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (have_100) {
+if (!out->WriteU16(1) ||
+!out->WriteU16(0) ||
+!out->WriteU32(offset_100 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (have_304) {
+if (!out->WriteU16(3) ||
+!out->WriteU16(0) ||
+!out->WriteU32(offset_304 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (have_314) {
+if (!out->WriteU16(3) ||
+!out->WriteU16(1) ||
+!out->WriteU32(offset_314 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (have_31012) {
+if (!out->WriteU16(3) ||
+!out->WriteU16(10) ||
+!out->WriteU32(offset_31012 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (have_31013) {
+if (!out->WriteU16(3) ||
+!out->WriteU16(10) ||
+!out->WriteU32(offset_31013 - table_start)) {
+return OTS_FAILURE();
+}
+}
+if (!out->Seek(table_end)) {
+return OTS_FAILURE();
+}
+out->RestoreChecksum(saved_checksum);
+return true;
+}
+void ots_cmap_free(OpenTypeFile *file) {
+delete file->cmap;
+}
+}  // namespace ots

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comparison: gfx/ots/src/cmap.cc

gfx/ots/src/cmap.cc