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// Copyright (c) 2010 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.
// A parser for the Type 2 Charstring Format.
// http://www.adobe.com/devnet/font/pdfs/5177.Type2.pdf
#include "cff_type2_charstring.h"
#include <climits>
#include <cstdio>
#include <cstring>
#include <stack>
#include <string>
#include <utility>
#define TABLE_NAME "CFF"
namespace {
// Type 2 Charstring Implementation Limits. See Appendix. B in Adobe Technical
// Note #5177.
const int32_t kMaxSubrsCount = 65536;
const size_t kMaxCharStringLength = 65535;
const size_t kMaxArgumentStack = 48;
const size_t kMaxNumberOfStemHints = 96;
const size_t kMaxSubrNesting = 10;
// |dummy_result| should be a huge positive integer so callsubr and callgsubr
// will fail with the dummy value.
const int32_t dummy_result = INT_MAX;
bool ExecuteType2CharString(ots::Font *font,
size_t call_depth,
const ots::CFFIndex& global_subrs_index,
const ots::CFFIndex& local_subrs_index,
ots::Buffer *cff_table,
ots::Buffer *char_string,
std::stack<int32_t> *argument_stack,
bool *out_found_endchar,
bool *out_found_width,
size_t *in_out_num_stems);
#ifdef DUMP_T2CHARSTRING
// Converts |op| to a string and returns it.
const char *Type2CharStringOperatorToString(ots::Type2CharStringOperator op) {
switch (op) {
case ots::kHStem:
return "HStem";
case ots::kVStem:
return "VStem";
case ots::kVMoveTo:
return "VMoveTo";
case ots::kRLineTo:
return "RLineTo";
case ots::kHLineTo:
return "HLineTo";
case ots::kVLineTo:
return "VLineTo";
case ots::kRRCurveTo:
return "RRCurveTo";
case ots::kCallSubr:
return "CallSubr";
case ots::kReturn:
return "Return";
case ots::kEndChar:
return "EndChar";
case ots::kHStemHm:
return "HStemHm";
case ots::kHintMask:
return "HintMask";
case ots::kCntrMask:
return "CntrMask";
case ots::kRMoveTo:
return "RMoveTo";
case ots::kHMoveTo:
return "HMoveTo";
case ots::kVStemHm:
return "VStemHm";
case ots::kRCurveLine:
return "RCurveLine";
case ots::kRLineCurve:
return "RLineCurve";
case ots::kVVCurveTo:
return "VVCurveTo";
case ots::kHHCurveTo:
return "HHCurveTo";
case ots::kCallGSubr:
return "CallGSubr";
case ots::kVHCurveTo:
return "VHCurveTo";
case ots::kHVCurveTo:
return "HVCurveTo";
case ots::kDotSection:
return "DotSection";
case ots::kAnd:
return "And";
case ots::kOr:
return "Or";
case ots::kNot:
return "Not";
case ots::kAbs:
return "Abs";
case ots::kAdd:
return "Add";
case ots::kSub:
return "Sub";
case ots::kDiv:
return "Div";
case ots::kNeg:
return "Neg";
case ots::kEq:
return "Eq";
case ots::kDrop:
return "Drop";
case ots::kPut:
return "Put";
case ots::kGet:
return "Get";
case ots::kIfElse:
return "IfElse";
case ots::kRandom:
return "Random";
case ots::kMul:
return "Mul";
case ots::kSqrt:
return "Sqrt";
case ots::kDup:
return "Dup";
case ots::kExch:
return "Exch";
case ots::kIndex:
return "Index";
case ots::kRoll:
return "Roll";
case ots::kHFlex:
return "HFlex";
case ots::kFlex:
return "Flex";
case ots::kHFlex1:
return "HFlex1";
case ots::kFlex1:
return "Flex1";
}
return "UNKNOWN";
}
#endif
// Read one or more bytes from the |char_string| buffer and stores the number
// read on |out_number|. If the number read is an operator (ex 'vstem'), sets
// true on |out_is_operator|. Returns true if the function read a number.
bool ReadNextNumberFromType2CharString(ots::Buffer *char_string,
int32_t *out_number,
bool *out_is_operator) {
uint8_t v = 0;
if (!char_string->ReadU8(&v)) {
return OTS_FAILURE();
}
*out_is_operator = false;
// The conversion algorithm is described in Adobe Technical Note #5177, page
// 13, Table 1.
if (v <= 11) {
*out_number = v;
*out_is_operator = true;
} else if (v == 12) {
uint16_t result = (v << 8);
if (!char_string->ReadU8(&v)) {
return OTS_FAILURE();
}
result += v;
*out_number = result;
*out_is_operator = true;
} else if (v <= 27) {
// Special handling for v==19 and v==20 are implemented in
// ExecuteType2CharStringOperator().
*out_number = v;
*out_is_operator = true;
} else if (v == 28) {
if (!char_string->ReadU8(&v)) {
return OTS_FAILURE();
}
uint16_t result = (v << 8);
if (!char_string->ReadU8(&v)) {
return OTS_FAILURE();
}
result += v;
*out_number = result;
} else if (v <= 31) {
*out_number = v;
*out_is_operator = true;
} else if (v <= 246) {
*out_number = static_cast<int32_t>(v) - 139;
} else if (v <= 250) {
uint8_t w = 0;
if (!char_string->ReadU8(&w)) {
return OTS_FAILURE();
}
*out_number = ((static_cast<int32_t>(v) - 247) * 256) +
static_cast<int32_t>(w) + 108;
} else if (v <= 254) {
uint8_t w = 0;
if (!char_string->ReadU8(&w)) {
return OTS_FAILURE();
}
*out_number = -((static_cast<int32_t>(v) - 251) * 256) -
static_cast<int32_t>(w) - 108;
} else if (v == 255) {
// TODO(yusukes): We should not skip the 4 bytes. Note that when v is 255,
// we should treat the following 4-bytes as a 16.16 fixed-point number
// rather than 32bit signed int.
if (!char_string->Skip(4)) {
return OTS_FAILURE();
}
*out_number = dummy_result;
} else {
return OTS_FAILURE();
}
return true;
}
// Executes |op| and updates |argument_stack|. Returns true if the execution
// succeeds. If the |op| is kCallSubr or kCallGSubr, the function recursively
// calls ExecuteType2CharString() function. The arguments other than |op| and
// |argument_stack| are passed for that reason.
bool ExecuteType2CharStringOperator(ots::Font *font,
int32_t op,
size_t call_depth,
const ots::CFFIndex& global_subrs_index,
const ots::CFFIndex& local_subrs_index,
ots::Buffer *cff_table,
ots::Buffer *char_string,
std::stack<int32_t> *argument_stack,
bool *out_found_endchar,
bool *in_out_found_width,
size_t *in_out_num_stems) {
const size_t stack_size = argument_stack->size();
switch (op) {
case ots::kCallSubr:
case ots::kCallGSubr: {
const ots::CFFIndex& subrs_index =
(op == ots::kCallSubr ? local_subrs_index : global_subrs_index);
if (stack_size < 1) {
return OTS_FAILURE();
}
int32_t subr_number = argument_stack->top();
argument_stack->pop();
if (subr_number == dummy_result) {
// For safety, we allow subr calls only with immediate subr numbers for
// now. For example, we allow "123 callgsubr", but does not allow "100 12
// add callgsubr". Please note that arithmetic and conditional operators
// always push the |dummy_result| in this implementation.
return OTS_FAILURE();
}
// See Adobe Technical Note #5176 (CFF), "16. Local/GlobalSubrs INDEXes."
int32_t bias = 32768;
if (subrs_index.count < 1240) {
bias = 107;
} else if (subrs_index.count < 33900) {
bias = 1131;
}
subr_number += bias;
// Sanity checks of |subr_number|.
if (subr_number < 0) {
return OTS_FAILURE();
}
if (subr_number >= kMaxSubrsCount) {
return OTS_FAILURE();
}
if (subrs_index.offsets.size() <= static_cast<size_t>(subr_number + 1)) {
return OTS_FAILURE(); // The number is out-of-bounds.
}
// Prepare ots::Buffer where we're going to jump.
const size_t length =
subrs_index.offsets[subr_number + 1] - subrs_index.offsets[subr_number];
if (length > kMaxCharStringLength) {
return OTS_FAILURE();
}
const size_t offset = subrs_index.offsets[subr_number];
cff_table->set_offset(offset);
if (!cff_table->Skip(length)) {
return OTS_FAILURE();
}
ots::Buffer char_string_to_jump(cff_table->buffer() + offset, length);
return ExecuteType2CharString(font,
call_depth + 1,
global_subrs_index,
local_subrs_index,
cff_table,
&char_string_to_jump,
argument_stack,
out_found_endchar,
in_out_found_width,
in_out_num_stems);
}
case ots::kReturn:
return true;
case ots::kEndChar:
*out_found_endchar = true;
*in_out_found_width = true; // just in case.
return true;
case ots::kHStem:
case ots::kVStem:
case ots::kHStemHm:
case ots::kVStemHm: {
bool successful = false;
if (stack_size < 2) {
return OTS_FAILURE();
}
if ((stack_size % 2) == 0) {
successful = true;
} else if ((!(*in_out_found_width)) && (((stack_size - 1) % 2) == 0)) {
// The -1 is for "width" argument. For details, see Adobe Technical Note
// #5177, page 16, note 4.
successful = true;
}
(*in_out_num_stems) += (stack_size / 2);
if ((*in_out_num_stems) > kMaxNumberOfStemHints) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
*in_out_found_width = true; // always set true since "w" might be 0 byte.
return successful ? true : OTS_FAILURE();
}
case ots::kRMoveTo: {
bool successful = false;
if (stack_size == 2) {
successful = true;
} else if ((!(*in_out_found_width)) && (stack_size - 1 == 2)) {
successful = true;
}
while (!argument_stack->empty())
argument_stack->pop();
*in_out_found_width = true;
return successful ? true : OTS_FAILURE();
}
case ots::kVMoveTo:
case ots::kHMoveTo: {
bool successful = false;
if (stack_size == 1) {
successful = true;
} else if ((!(*in_out_found_width)) && (stack_size - 1 == 1)) {
successful = true;
}
while (!argument_stack->empty())
argument_stack->pop();
*in_out_found_width = true;
return successful ? true : OTS_FAILURE();
}
case ots::kHintMask:
case ots::kCntrMask: {
bool successful = false;
if (stack_size == 0) {
successful = true;
} else if ((!(*in_out_found_width)) && (stack_size == 1)) {
// A number for "width" is found.
successful = true;
} else if ((!(*in_out_found_width)) || // in this case, any sizes are ok.
((stack_size % 2) == 0)) {
// The numbers are vstem definition.
// See Adobe Technical Note #5177, page 24, hintmask.
(*in_out_num_stems) += (stack_size / 2);
if ((*in_out_num_stems) > kMaxNumberOfStemHints) {
return OTS_FAILURE();
}
successful = true;
}
if (!successful) {
return OTS_FAILURE();
}
if ((*in_out_num_stems) == 0) {
return OTS_FAILURE();
}
const size_t mask_bytes = (*in_out_num_stems + 7) / 8;
if (!char_string->Skip(mask_bytes)) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
*in_out_found_width = true;
return true;
}
case ots::kRLineTo:
if (!(*in_out_found_width)) {
// The first stack-clearing operator should be one of hstem, hstemhm,
// vstem, vstemhm, cntrmask, hintmask, hmoveto, vmoveto, rmoveto, or
// endchar. For details, see Adobe Technical Note #5177, page 16, note 4.
return OTS_FAILURE();
}
if (stack_size < 2) {
return OTS_FAILURE();
}
if ((stack_size % 2) != 0) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kHLineTo:
case ots::kVLineTo:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 1) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kRRCurveTo:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 6) {
return OTS_FAILURE();
}
if ((stack_size % 6) != 0) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kRCurveLine:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 8) {
return OTS_FAILURE();
}
if (((stack_size - 2) % 6) != 0) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kRLineCurve:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 8) {
return OTS_FAILURE();
}
if (((stack_size - 6) % 2) != 0) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kVVCurveTo:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 4) {
return OTS_FAILURE();
}
if (((stack_size % 4) != 0) &&
(((stack_size - 1) % 4) != 0)) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kHHCurveTo: {
bool successful = false;
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 4) {
return OTS_FAILURE();
}
if ((stack_size % 4) == 0) {
// {dxa dxb dyb dxc}+
successful = true;
} else if (((stack_size - 1) % 4) == 0) {
// dy1? {dxa dxb dyb dxc}+
successful = true;
}
while (!argument_stack->empty())
argument_stack->pop();
return successful ? true : OTS_FAILURE();
}
case ots::kVHCurveTo:
case ots::kHVCurveTo: {
bool successful = false;
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size < 4) {
return OTS_FAILURE();
}
if (((stack_size - 4) % 8) == 0) {
// dx1 dx2 dy2 dy3 {dya dxb dyb dxc dxd dxe dye dyf}*
successful = true;
} else if ((stack_size >= 5) &&
((stack_size - 5) % 8) == 0) {
// dx1 dx2 dy2 dy3 {dya dxb dyb dxc dxd dxe dye dyf}* dxf
successful = true;
} else if ((stack_size >= 8) &&
((stack_size - 8) % 8) == 0) {
// {dxa dxb dyb dyc dyd dxe dye dxf}+
successful = true;
} else if ((stack_size >= 9) &&
((stack_size - 9) % 8) == 0) {
// {dxa dxb dyb dyc dyd dxe dye dxf}+ dyf?
successful = true;
}
while (!argument_stack->empty())
argument_stack->pop();
return successful ? true : OTS_FAILURE();
}
case ots::kDotSection:
// Deprecated operator but harmless, we probably should drop it some how.
if (stack_size != 0) {
return OTS_FAILURE();
}
return true;
case ots::kAnd:
case ots::kOr:
case ots::kEq:
case ots::kAdd:
case ots::kSub:
if (stack_size < 2) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->pop();
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kNot:
case ots::kAbs:
case ots::kNeg:
if (stack_size < 1) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kDiv:
// TODO(yusukes): Should detect div-by-zero errors.
if (stack_size < 2) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->pop();
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kDrop:
if (stack_size < 1) {
return OTS_FAILURE();
}
argument_stack->pop();
return true;
case ots::kPut:
case ots::kGet:
case ots::kIndex:
// For now, just call OTS_FAILURE since there is no way to check whether the
// index argument, |i|, is out-of-bounds or not. Fortunately, no OpenType
// fonts I have (except malicious ones!) use the operators.
// TODO(yusukes): Implement them in a secure way.
return OTS_FAILURE();
case ots::kRoll:
// Likewise, just call OTS_FAILURE for kRoll since there is no way to check
// whether |N| is smaller than the current stack depth or not.
// TODO(yusukes): Implement them in a secure way.
return OTS_FAILURE();
case ots::kRandom:
// For now, we don't handle the 'random' operator since the operator makes
// it hard to analyze hinting code statically.
return OTS_FAILURE();
case ots::kIfElse:
if (stack_size < 4) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->pop();
argument_stack->pop();
argument_stack->pop();
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kMul:
// TODO(yusukes): Should detect overflows.
if (stack_size < 2) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->pop();
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kSqrt:
// TODO(yusukes): Should check if the argument is negative.
if (stack_size < 1) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kDup:
if (stack_size < 1) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->push(dummy_result);
argument_stack->push(dummy_result);
if (argument_stack->size() > kMaxArgumentStack) {
return OTS_FAILURE();
}
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kExch:
if (stack_size < 2) {
return OTS_FAILURE();
}
argument_stack->pop();
argument_stack->pop();
argument_stack->push(dummy_result);
argument_stack->push(dummy_result);
// TODO(yusukes): Implement this. We should push a real value for all
// arithmetic and conditional operations.
return true;
case ots::kHFlex:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size != 7) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kFlex:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size != 13) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kHFlex1:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size != 9) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
case ots::kFlex1:
if (!(*in_out_found_width)) {
return OTS_FAILURE();
}
if (stack_size != 11) {
return OTS_FAILURE();
}
while (!argument_stack->empty())
argument_stack->pop();
return true;
}
return OTS_FAILURE_MSG("Undefined operator: %d (0x%x)", op, op);
}
// Executes |char_string| and updates |argument_stack|.
//
// call_depth: The current call depth. Initial value is zero.
// global_subrs_index: Global subroutines.
// local_subrs_index: Local subroutines for the current glyph.
// cff_table: A whole CFF table which contains all global and local subroutines.
// char_string: A charstring we'll execute. |char_string| can be a main routine
// in CharString INDEX, or a subroutine in GlobalSubr/LocalSubr.
// argument_stack: The stack which an operator in |char_string| operates.
// out_found_endchar: true is set if |char_string| contains 'endchar'.
// in_out_found_width: true is set if |char_string| contains 'width' byte (which
// is 0 or 1 byte.)
// in_out_num_stems: total number of hstems and vstems processed so far.
bool ExecuteType2CharString(ots::Font *font,
size_t call_depth,
const ots::CFFIndex& global_subrs_index,
const ots::CFFIndex& local_subrs_index,
ots::Buffer *cff_table,
ots::Buffer *char_string,
std::stack<int32_t> *argument_stack,
bool *out_found_endchar,
bool *in_out_found_width,
size_t *in_out_num_stems) {
if (call_depth > kMaxSubrNesting) {
return OTS_FAILURE();
}
*out_found_endchar = false;
const size_t length = char_string->length();
while (char_string->offset() < length) {
int32_t operator_or_operand = 0;
bool is_operator = false;
if (!ReadNextNumberFromType2CharString(char_string,
&operator_or_operand,
&is_operator)) {
return OTS_FAILURE();
}
#ifdef DUMP_T2CHARSTRING
/*
You can dump all operators and operands (except mask bytes for hintmask
and cntrmask) by the following code:
*/
if (!is_operator) {
std::fprintf(stderr, "#%d# ", operator_or_operand);
} else {
std::fprintf(stderr, "#%s#\n",
Type2CharStringOperatorToString(
ots::Type2CharStringOperator(operator_or_operand))
);
}
#endif
if (!is_operator) {
argument_stack->push(operator_or_operand);
if (argument_stack->size() > kMaxArgumentStack) {
return OTS_FAILURE();
}
continue;
}
// An operator is found. Execute it.
if (!ExecuteType2CharStringOperator(font,
operator_or_operand,
call_depth,
global_subrs_index,
local_subrs_index,
cff_table,
char_string,
argument_stack,
out_found_endchar,
in_out_found_width,
in_out_num_stems)) {
return OTS_FAILURE();
}
if (*out_found_endchar) {
return true;
}
if (operator_or_operand == ots::kReturn) {
return true;
}
}
// No endchar operator is found.
return OTS_FAILURE();
}
// Selects a set of subroutings for |glyph_index| from |cff| and sets it on
// |out_local_subrs_to_use|. Returns true on success.
bool SelectLocalSubr(const std::map<uint16_t, uint8_t> &fd_select,
const std::vector<ots::CFFIndex *> &local_subrs_per_font,
const ots::CFFIndex *local_subrs,
uint16_t glyph_index, // 0-origin
const ots::CFFIndex **out_local_subrs_to_use) {
*out_local_subrs_to_use = NULL;
// First, find local subrs from |local_subrs_per_font|.
if ((fd_select.size() > 0) &&
(!local_subrs_per_font.empty())) {
// Look up FDArray index for the glyph.
std::map<uint16_t, uint8_t>::const_iterator iter =
fd_select.find(glyph_index);
if (iter == fd_select.end()) {
return OTS_FAILURE();
}
const uint8_t fd_index = iter->second;
if (fd_index >= local_subrs_per_font.size()) {
return OTS_FAILURE();
}
*out_local_subrs_to_use = local_subrs_per_font.at(fd_index);
} else if (local_subrs) {
// Second, try to use |local_subrs|. Most Latin fonts don't have FDSelect
// entries. If The font has a local subrs index associated with the Top
// DICT (not FDArrays), use it.
*out_local_subrs_to_use = local_subrs;
} else {
// Just return NULL.
*out_local_subrs_to_use = NULL;
}
return true;
}
} // namespace
namespace ots {
bool ValidateType2CharStringIndex(
ots::Font *font,
const CFFIndex& char_strings_index,
const CFFIndex& global_subrs_index,
const std::map<uint16_t, uint8_t> &fd_select,
const std::vector<CFFIndex *> &local_subrs_per_font,
const CFFIndex *local_subrs,
Buffer* cff_table) {
if (char_strings_index.offsets.size() == 0) {
return OTS_FAILURE(); // no charstring.
}
// For each glyph, validate the corresponding charstring.
for (unsigned i = 1; i < char_strings_index.offsets.size(); ++i) {
// Prepare a Buffer object, |char_string|, which contains the charstring
// for the |i|-th glyph.
const size_t length =
char_strings_index.offsets[i] - char_strings_index.offsets[i - 1];
if (length > kMaxCharStringLength) {
return OTS_FAILURE();
}
const size_t offset = char_strings_index.offsets[i - 1];
cff_table->set_offset(offset);
if (!cff_table->Skip(length)) {
return OTS_FAILURE();
}
Buffer char_string(cff_table->buffer() + offset, length);
// Get a local subrs for the glyph.
const unsigned glyph_index = i - 1; // index in the map is 0-origin.
const CFFIndex *local_subrs_to_use = NULL;
if (!SelectLocalSubr(fd_select,
local_subrs_per_font,
local_subrs,
glyph_index,
&local_subrs_to_use)) {
return OTS_FAILURE();
}
// If |local_subrs_to_use| is still NULL, use an empty one.
CFFIndex default_empty_subrs;
if (!local_subrs_to_use){
local_subrs_to_use = &default_empty_subrs;
}
// Check a charstring for the |i|-th glyph.
std::stack<int32_t> argument_stack;
bool found_endchar = false;
bool found_width = false;
size_t num_stems = 0;
if (!ExecuteType2CharString(font,
0 /* initial call_depth is zero */,
global_subrs_index, *local_subrs_to_use,
cff_table, &char_string, &argument_stack,
&found_endchar, &found_width, &num_stems)) {
return OTS_FAILURE();
}
if (!found_endchar) {
return OTS_FAILURE();
}
}
return true;
}
} // namespace ots
#undef TABLE_NAME