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Unified Diff: third_party/ots/src/cff_type2_charstring.cc

Issue 775893002: Updating OTS repo from https://github.com/khaledhosny/ots.git (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Updating with 4800 warning fix Created 6 years ago
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Index: third_party/ots/src/cff_type2_charstring.cc
diff --git a/third_party/ots/src/cff_type2_charstring.cc b/third_party/ots/src/cff_type2_charstring.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6dd47664d09128a1dfcbe7a92921e37e97d1cac6
--- /dev/null
+++ b/third_party/ots/src/cff_type2_charstring.cc
@@ -0,0 +1,914 @@
+// 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::OpenTypeFile *file,
+ 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::OpenTypeFile *file,
+ 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(file,
+ 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::OpenTypeFile *file,
+ 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(file,
+ 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::OpenTypeFile *file,
+ 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) {
+ const uint16_t num_offsets =
+ static_cast<uint16_t>(char_strings_index.offsets.size());
+ if (num_offsets != char_strings_index.offsets.size() || num_offsets == 0) {
+ return OTS_FAILURE(); // no charstring.
+ }
+
+ // For each glyph, validate the corresponding charstring.
+ for (uint16_t i = 1; i < num_offsets; ++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 uint16_t 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(file,
+ 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
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