Reland of Unify some code

testing/libfuzzer/pdf_hint_table_fuzzer.cc

 // Copyright 2016 The PDFium 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 <cstdint>
 
+#include "core/fpdfapi/parser/cpdf_array.h"
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfapi/parser/cpdf_hint_tables.h"
-
-struct DummyLinearizedDictionary {
-  int end_of_first_page_offset;
-  int number_of_pages;
-  int first_page_object_number;
-  int first_page_number;
-  int primary_hint_stream_offset;
-  int primary_hint_stream_length;
-  int shared_hint_table_offset;
-};
+#include "core/fpdfapi/parser/cpdf_linearized.h"
+#include "third_party/base/ptr_util.h"
 
 int32_t GetData(const int32_t** data32, const uint8_t** data, size_t* size) {
   const int32_t* ret = *data32;
   ++(*data32);
   *data += 4;
   *size -= 4;
   return *ret;
 }
 
 class HintTableForFuzzing : public CPDF_HintTables {
  public:
-  HintTableForFuzzing(DummyLinearizedDictionary* dict,
-                      CPDF_Dictionary* linearized_dict)
-      : CPDF_HintTables(nullptr, linearized_dict), dict_(dict) {}
+  HintTableForFuzzing(CPDF_Linearized* pLinearized,
+                      int shared_hint_table_offset)
+      : CPDF_HintTables(nullptr, pLinearized),
+        shared_hint_table_offset_(shared_hint_table_offset) {}
   ~HintTableForFuzzing() {}
 
   void Fuzz(const uint8_t* data, size_t size) {
-    if (dict_->shared_hint_table_offset <= 0)
+    if (shared_hint_table_offset_ <= 0)
       return;
 
-    if (size < static_cast<size_t>(dict_->shared_hint_table_offset))
+    if (size < static_cast<size_t>(shared_hint_table_offset_))
       return;
 
     CFX_BitStream bs;
     bs.Init(data, size);
     if (!ReadPageHintTable(&bs))
       return;
-    ReadSharedObjHintTable(&bs, dict_->shared_hint_table_offset);
+    ReadSharedObjHintTable(&bs, shared_hint_table_offset_);
   }
 
  private:
-  int GetEndOfFirstPageOffset() const override {
-    return dict_->end_of_first_page_offset;
-  }
-  int GetNumberOfPages() const override { return dict_->number_of_pages; }
-  int GetFirstPageObjectNumber() const override {
-    return dict_->first_page_object_number;
-  }
-  int GetFirstPageNumber() const override { return dict_->first_page_number; }
-  int ReadPrimaryHintStreamOffset() const override {
-    return dict_->primary_hint_stream_offset;
-  }
-  int ReadPrimaryHintStreamLength() const override {
-    return dict_->primary_hint_stream_length;
-  }
+  int shared_hint_table_offset_;
+};
 
-  DummyLinearizedDictionary* const dict_;
+class FakeLinearized : public CPDF_Linearized {
+ public:
+  explicit FakeLinearized(CPDF_Dictionary* linearized_dict)
+      : CPDF_Linearized(linearized_dict) {}
 };
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  // Need 28 bytes for |dummy_dict|.
+  // Need 28 bytes for |linearized_dict|.
   // The header section of page offset hint table is 36 bytes.
   // The header section of shared object hint table is 24 bytes.
   if (size < 28 + 36 + 24)
     return 0;
 
   const int32_t* data32 = reinterpret_cast<const int32_t*>(data);
-  DummyLinearizedDictionary dummy_dict;
-  dummy_dict.end_of_first_page_offset = GetData(&data32, &data, &size);
-  dummy_dict.number_of_pages = GetData(&data32, &data, &size);
-  dummy_dict.first_page_object_number = GetData(&data32, &data, &size);
-  dummy_dict.first_page_number = GetData(&data32, &data, &size);
-  dummy_dict.primary_hint_stream_offset = GetData(&data32, &data, &size);
-  dummy_dict.primary_hint_stream_length = GetData(&data32, &data, &size);
-  dummy_dict.shared_hint_table_offset = GetData(&data32, &data, &size);
 
-  std::unique_ptr<CPDF_Dictionary> dummy_linearized_dict(new CPDF_Dictionary);
+  auto linearized_dict = pdfium::MakeUnique<CPDF_Dictionary>();
+  // Set initial value.
+  linearized_dict->SetBooleanFor("Linearized", true);
+  // Set first page end offset
+  linearized_dict->SetIntegerFor("E", GetData(&data32, &data, &size));
+  // Set page count
+  linearized_dict->SetIntegerFor("N", GetData(&data32, &data, &size));
+  // Set first page obj num
+  linearized_dict->SetIntegerFor("O", GetData(&data32, &data, &size));
+  // Set first page no
+  linearized_dict->SetIntegerFor("P", GetData(&data32, &data, &size));
+
+  auto hint_info = pdfium::MakeUnique<CPDF_Array>();
+  // Add primary hint stream offset
+  hint_info->AddInteger(GetData(&data32, &data, &size));
+  // Add primary hint stream size
+  hint_info->AddInteger(GetData(&data32, &data, &size));
+  // Set hint stream info.
+  linearized_dict->SetFor("H", hint_info.release());
+
+  const int shared_hint_table_offset = GetData(&data32, &data, &size);
+
   {
-    HintTableForFuzzing hint_table(&dummy_dict, dummy_linearized_dict.get());
+    FakeLinearized linearized(linearized_dict.get());
+    HintTableForFuzzing hint_table(&linearized, shared_hint_table_offset);
     hint_table.Fuzz(data, size);
   }
   return 0;
 }