compiler/image_writer.cc

   1 /*
   2  * Copyright (C) 2011 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "image_writer.h"
  18
  19 #include <sys/stat.h>
  20 #include <lz4.h>
  21 #include <lz4hc.h>
  22
  23 #include <memory>
  24 #include <numeric>
  25 #include <unordered_set>
  26 #include <vector>
  27
  28 #include "art_field-inl.h"
  29 #include "art_method-inl.h"
  30 #include "base/logging.h"
  31 #include "base/unix_file/fd_file.h"
  32 #include "class_linker-inl.h"
  33 #include "compiled_method.h"
  34 #include "dex_file-inl.h"
  35 #include "driver/compiler_driver.h"
  36 #include "elf_file.h"
  37 #include "elf_utils.h"
  38 #include "elf_writer.h"
  39 #include "gc/accounting/card_table-inl.h"
  40 #include "gc/accounting/heap_bitmap.h"
  41 #include "gc/accounting/space_bitmap-inl.h"
  42 #include "gc/heap.h"
  43 #include "gc/space/large_object_space.h"
  44 #include "gc/space/space-inl.h"
  45 #include "globals.h"
  46 #include "image.h"
  47 #include "intern_table.h"
  48 #include "linear_alloc.h"
  49 #include "lock_word.h"
  50 #include "mirror/abstract_method.h"
  51 #include "mirror/array-inl.h"
  52 #include "mirror/class-inl.h"
  53 #include "mirror/class_loader.h"
  54 #include "mirror/dex_cache-inl.h"
  55 #include "mirror/method.h"
  56 #include "mirror/object-inl.h"
  57 #include "mirror/object_array-inl.h"
  58 #include "mirror/string-inl.h"
  59 #include "oat.h"
  60 #include "oat_file.h"
  61 #include "oat_file_manager.h"
  62 #include "runtime.h"
  63 #include "scoped_thread_state_change.h"
  64 #include "handle_scope-inl.h"
  65 #include "utils/dex_cache_arrays_layout-inl.h"
  66
  67 using ::art::mirror::Class;
  68 using ::art::mirror::DexCache;
  69 using ::art::mirror::Object;
  70 using ::art::mirror::ObjectArray;
  71 using ::art::mirror::String;
  72
  73 namespace art {
  74
  75 // Separate objects into multiple bins to optimize dirty memory use.
  76 static constexpr bool kBinObjects = true;
  77
  78 // Return true if an object is already in an image space.
  79 bool ImageWriter::IsInBootImage(const void* obj) const {
  80   gc::Heap* const heap = Runtime::Current()->GetHeap();
  81   if (!compile_app_image_) {
  82     DCHECK(heap->GetBootImageSpaces().empty());
  83     return false;
  84   }
  85   for (gc::space::ImageSpace* boot_image_space : heap->GetBootImageSpaces()) {
  86     const uint8_t* image_begin = boot_image_space->Begin();
  87     // Real image end including ArtMethods and ArtField sections.
  88     const uint8_t* image_end = image_begin + boot_image_space->GetImageHeader().GetImageSize();
  89     if (image_begin <= obj && obj < image_end) {
  90       return true;
  91     }
  92   }
  93   return false;
  94 }
  95
  96 bool ImageWriter::IsInBootOatFile(const void* ptr) const {
  97   gc::Heap* const heap = Runtime::Current()->GetHeap();
  98   if (!compile_app_image_) {
  99     DCHECK(heap->GetBootImageSpaces().empty());
 100     return false;
 101   }
 102   for (gc::space::ImageSpace* boot_image_space : heap->GetBootImageSpaces()) {
 103     const ImageHeader& image_header = boot_image_space->GetImageHeader();
 104     if (image_header.GetOatFileBegin() <= ptr && ptr < image_header.GetOatFileEnd()) {
 105       return true;
 106     }
 107   }
 108   return false;
 109 }
 110
 111 static void CheckNoDexObjectsCallback(Object* obj, void* arg ATTRIBUTE_UNUSED)
 112     SHARED_REQUIRES(Locks::mutator_lock_) {
 113   Class* klass = obj->GetClass();
 114   CHECK_NE(PrettyClass(klass), "com.android.dex.Dex");
 115 }
 116
 117 static void CheckNoDexObjects() {
 118   ScopedObjectAccess soa(Thread::Current());
 119   Runtime::Current()->GetHeap()->VisitObjects(CheckNoDexObjectsCallback, nullptr);
 120 }
 121
 122 bool ImageWriter::PrepareImageAddressSpace() {
 123   target_ptr_size_ = InstructionSetPointerSize(compiler_driver_.GetInstructionSet());
 124   gc::Heap* const heap = Runtime::Current()->GetHeap();
 125   {
 126     ScopedObjectAccess soa(Thread::Current());
 127     PruneNonImageClasses();  // Remove junk
 128     if (!compile_app_image_) {
 129       // Avoid for app image since this may increase RAM and image size.
 130       ComputeLazyFieldsForImageClasses();  // Add useful information
 131     }
 132   }
 133   heap->CollectGarbage(false);  // Remove garbage.
 134
 135   // Dex caches must not have their dex fields set in the image. These are memory buffers of mapped
 136   // dex files.
 137   //
 138   // We may open them in the unstarted-runtime code for class metadata. Their fields should all be
 139   // reset in PruneNonImageClasses and the objects reclaimed in the GC. Make sure that's actually
 140   // true.
 141   if (kIsDebugBuild) {
 142     CheckNoDexObjects();
 143   }
 144
 145   if (kIsDebugBuild) {
 146     ScopedObjectAccess soa(Thread::Current());
 147     CheckNonImageClassesRemoved();
 148   }
 149
 150   {
 151     ScopedObjectAccess soa(Thread::Current());
 152     CalculateNewObjectOffsets();
 153   }
 154
 155   // This needs to happen after CalculateNewObjectOffsets since it relies on intern_table_bytes_ and
 156   // bin size sums being calculated.
 157   if (!AllocMemory()) {
 158     return false;
 159   }
 160
 161   return true;
 162 }
 163
 164 bool ImageWriter::Write(int image_fd,
 165                         const std::vector<const char*>& image_filenames,
 166                         const std::vector<const char*>& oat_filenames) {
 167   // If image_fd or oat_fd are not kInvalidFd then we may have empty strings in image_filenames or
 168   // oat_filenames.
 169   CHECK(!image_filenames.empty());
 170   if (image_fd != kInvalidFd) {
 171     CHECK_EQ(image_filenames.size(), 1u);
 172   }
 173   CHECK(!oat_filenames.empty());
 174   CHECK_EQ(image_filenames.size(), oat_filenames.size());
 175
 176   {
 177     ScopedObjectAccess soa(Thread::Current());
 178     for (size_t i = 0; i < oat_filenames.size(); ++i) {
 179       CreateHeader(i);
 180       CopyAndFixupNativeData(i);
 181     }
 182   }
 183
 184   {
 185     // TODO: heap validation can't handle these fix up passes.
 186     ScopedObjectAccess soa(Thread::Current());
 187     Runtime::Current()->GetHeap()->DisableObjectValidation();
 188     CopyAndFixupObjects();
 189   }
 190
 191   for (size_t i = 0; i < image_filenames.size(); ++i) {
 192     const char* image_filename = image_filenames[i];
 193     ImageInfo& image_info = GetImageInfo(i);
 194     std::unique_ptr<File> image_file;
 195     if (image_fd != kInvalidFd) {
 196       if (strlen(image_filename) == 0u) {
 197         image_file.reset(new File(image_fd, unix_file::kCheckSafeUsage));
 198         // Empty the file in case it already exists.
 199         if (image_file != nullptr) {
 200           TEMP_FAILURE_RETRY(image_file->SetLength(0));
 201           TEMP_FAILURE_RETRY(image_file->Flush());
 202         }
 203       } else {
 204         LOG(ERROR) << "image fd " << image_fd << " name " << image_filename;
 205       }
 206     } else {
 207       image_file.reset(OS::CreateEmptyFile(image_filename));
 208     }
 209
 210     if (image_file == nullptr) {
 211       LOG(ERROR) << "Failed to open image file " << image_filename;
 212       return false;
 213     }
 214
 215     if (!compile_app_image_ && fchmod(image_file->Fd(), 0644) != 0) {
 216       PLOG(ERROR) << "Failed to make image file world readable: " << image_filename;
 217       image_file->Erase();
 218       return EXIT_FAILURE;
 219     }
 220
 221     std::unique_ptr<char[]> compressed_data;
 222     // Image data size excludes the bitmap and the header.
 223     ImageHeader* const image_header = reinterpret_cast<ImageHeader*>(image_info.image_->Begin());
 224     const size_t image_data_size = image_header->GetImageSize() - sizeof(ImageHeader);
 225     char* image_data = reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader);
 226     size_t data_size;
 227     const char* image_data_to_write;
 228     const uint64_t compress_start_time = NanoTime();
 229
 230     CHECK_EQ(image_header->storage_mode_, image_storage_mode_);
 231     switch (image_storage_mode_) {
 232       case ImageHeader::kStorageModeLZ4: {
 233         const size_t compressed_max_size = LZ4_compressBound(image_data_size);
 234         compressed_data.reset(new char[compressed_max_size]);
 235         data_size = LZ4_compress(
 236             reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader),
 237             &compressed_data[0],
 238             image_data_size);
 239
 240         break;
 241       }
 242       case ImageHeader::kStorageModeLZ4HC: {
 243         // Bound is same as non HC.
 244         const size_t compressed_max_size = LZ4_compressBound(image_data_size);
 245         compressed_data.reset(new char[compressed_max_size]);
 246         data_size = LZ4_compressHC(
 247             reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader),
 248             &compressed_data[0],
 249             image_data_size);
 250         break;
 251       }
 252       case ImageHeader::kStorageModeUncompressed: {
 253         data_size = image_data_size;
 254         image_data_to_write = image_data;
 255         break;
 256       }
 257       default: {
 258         LOG(FATAL) << "Unsupported";
 259         UNREACHABLE();
 260       }
 261     }
 262
 263     if (compressed_data != nullptr) {
 264       image_data_to_write = &compressed_data[0];
 265       VLOG(compiler) << "Compressed from " << image_data_size << " to " << data_size << " in "
 266                      << PrettyDuration(NanoTime() - compress_start_time);
 267     }
 268
 269     // Write out the image + fields + methods.
 270     const bool is_compressed = compressed_data != nullptr;
 271     if (!image_file->PwriteFully(image_data_to_write, data_size, sizeof(ImageHeader))) {
 272       PLOG(ERROR) << "Failed to write image file data " << image_filename;
 273       image_file->Erase();
 274       return false;
 275     }
 276
 277     // Write out the image bitmap at the page aligned start of the image end, also uncompressed for
 278     // convenience.
 279     const ImageSection& bitmap_section = image_header->GetImageSection(
 280         ImageHeader::kSectionImageBitmap);
 281     // Align up since data size may be unaligned if the image is compressed.
 282     size_t bitmap_position_in_file = RoundUp(sizeof(ImageHeader) + data_size, kPageSize);
 283     if (!is_compressed) {
 284       CHECK_EQ(bitmap_position_in_file, bitmap_section.Offset());
 285     }
 286     if (!image_file->PwriteFully(reinterpret_cast<char*>(image_info.image_bitmap_->Begin()),
 287                                  bitmap_section.Size(),
 288                                  bitmap_position_in_file)) {
 289       PLOG(ERROR) << "Failed to write image file " << image_filename;
 290       image_file->Erase();
 291       return false;
 292     }
 293
 294     int err = image_file->Flush();
 295     if (err < 0) {
 296       PLOG(ERROR) << "Failed to flush image file " << image_filename << " with result " << err;
 297       image_file->Erase();
 298       return false;
 299     }
 300
 301     // Write header last in case the compiler gets killed in the middle of image writing.
 302     // We do not want to have a corrupted image with a valid header.
 303     // The header is uncompressed since it contains whether the image is compressed or not.
 304     image_header->data_size_ = data_size;
 305     if (!image_file->PwriteFully(reinterpret_cast<char*>(image_info.image_->Begin()),
 306                                  sizeof(ImageHeader),
 307                                  0)) {
 308       PLOG(ERROR) << "Failed to write image file header " << image_filename;
 309       image_file->Erase();
 310       return false;
 311     }
 312
 313     CHECK_EQ(bitmap_position_in_file + bitmap_section.Size(),
 314              static_cast<size_t>(image_file->GetLength()));
 315     if (image_file->FlushCloseOrErase() != 0) {
 316       PLOG(ERROR) << "Failed to flush and close image file " << image_filename;
 317       return false;
 318     }
 319   }
 320   return true;
 321 }
 322
 323 void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
 324   DCHECK(object != nullptr);
 325   DCHECK_NE(offset, 0U);
 326
 327   // The object is already deflated from when we set the bin slot. Just overwrite the lock word.
 328   object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
 329   DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u);
 330   DCHECK(IsImageOffsetAssigned(object));
 331 }
 332
 333 void ImageWriter::UpdateImageOffset(mirror::Object* obj, uintptr_t offset) {
 334   DCHECK(IsImageOffsetAssigned(obj)) << obj << " " << offset;
 335   obj->SetLockWord(LockWord::FromForwardingAddress(offset), false);
 336   DCHECK_EQ(obj->GetLockWord(false).ReadBarrierState(), 0u);
 337 }
 338
 339 void ImageWriter::AssignImageOffset(mirror::Object* object, ImageWriter::BinSlot bin_slot) {
 340   DCHECK(object != nullptr);
 341   DCHECK_NE(image_objects_offset_begin_, 0u);
 342
 343   size_t oat_index = GetOatIndex(object);
 344   ImageInfo& image_info = GetImageInfo(oat_index);
 345   size_t bin_slot_offset = image_info.bin_slot_offsets_[bin_slot.GetBin()];
 346   size_t new_offset = bin_slot_offset + bin_slot.GetIndex();
 347   DCHECK_ALIGNED(new_offset, kObjectAlignment);
 348
 349   SetImageOffset(object, new_offset);
 350   DCHECK_LT(new_offset, image_info.image_end_);
 351 }
 352
 353 bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
 354   // Will also return true if the bin slot was assigned since we are reusing the lock word.
 355   DCHECK(object != nullptr);
 356   return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress;
 357 }
 358
 359 size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
 360   DCHECK(object != nullptr);
 361   DCHECK(IsImageOffsetAssigned(object));
 362   LockWord lock_word = object->GetLockWord(false);
 363   size_t offset = lock_word.ForwardingAddress();
 364   size_t oat_index = GetOatIndex(object);
 365   const ImageInfo& image_info = GetImageInfo(oat_index);
 366   DCHECK_LT(offset, image_info.image_end_);
 367   return offset;
 368 }
 369
 370 void ImageWriter::SetImageBinSlot(mirror::Object* object, BinSlot bin_slot) {
 371   DCHECK(object != nullptr);
 372   DCHECK(!IsImageOffsetAssigned(object));
 373   DCHECK(!IsImageBinSlotAssigned(object));
 374
 375   // Before we stomp over the lock word, save the hash code for later.
 376   Monitor::Deflate(Thread::Current(), object);;
 377   LockWord lw(object->GetLockWord(false));
 378   switch (lw.GetState()) {
 379     case LockWord::kFatLocked: {
 380       LOG(FATAL) << "Fat locked object " << object << " found during object copy";
 381       break;
 382     }
 383     case LockWord::kThinLocked: {
 384       LOG(FATAL) << "Thin locked object " << object << " found during object copy";
 385       break;
 386     }
 387     case LockWord::kUnlocked:
 388       // No hash, don't need to save it.
 389       break;
 390     case LockWord::kHashCode:
 391       DCHECK(saved_hashcode_map_.find(object) == saved_hashcode_map_.end());
 392       saved_hashcode_map_.emplace(object, lw.GetHashCode());
 393       break;
 394     default:
 395       LOG(FATAL) << "Unreachable.";
 396       UNREACHABLE();
 397   }
 398   object->SetLockWord(LockWord::FromForwardingAddress(bin_slot.Uint32Value()), false);
 399   DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u);
 400   DCHECK(IsImageBinSlotAssigned(object));
 401 }
 402
 403 void ImageWriter::PrepareDexCacheArraySlots() {
 404   // Prepare dex cache array starts based on the ordering specified in the CompilerDriver.
 405   // Set the slot size early to avoid DCHECK() failures in IsImageBinSlotAssigned()
 406   // when AssignImageBinSlot() assigns their indexes out or order.
 407   for (const DexFile* dex_file : compiler_driver_.GetDexFilesForOatFile()) {
 408     auto it = dex_file_oat_index_map_.find(dex_file);
 409     DCHECK(it != dex_file_oat_index_map_.end()) << dex_file->GetLocation();
 410     ImageInfo& image_info = GetImageInfo(it->second);
 411     image_info.dex_cache_array_starts_.Put(dex_file, image_info.bin_slot_sizes_[kBinDexCacheArray]);
 412     DexCacheArraysLayout layout(target_ptr_size_, dex_file);
 413     image_info.bin_slot_sizes_[kBinDexCacheArray] += layout.Size();
 414   }
 415
 416   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
 417   Thread* const self = Thread::Current();
 418   ReaderMutexLock mu(self, *class_linker->DexLock());
 419   for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
 420     mirror::DexCache* dex_cache =
 421         down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
 422     if (dex_cache == nullptr || IsInBootImage(dex_cache)) {
 423       continue;
 424     }
 425     const DexFile* dex_file = dex_cache->GetDexFile();
 426     DexCacheArraysLayout layout(target_ptr_size_, dex_file);
 427     DCHECK(layout.Valid());
 428     size_t oat_index = GetOatIndexForDexCache(dex_cache);
 429     ImageInfo& image_info = GetImageInfo(oat_index);
 430     uint32_t start = image_info.dex_cache_array_starts_.Get(dex_file);
 431     DCHECK_EQ(dex_file->NumTypeIds() != 0u, dex_cache->GetResolvedTypes() != nullptr);
 432     AddDexCacheArrayRelocation(dex_cache->GetResolvedTypes(),
 433                                start + layout.TypesOffset(),
 434                                dex_cache);
 435     DCHECK_EQ(dex_file->NumMethodIds() != 0u, dex_cache->GetResolvedMethods() != nullptr);
 436     AddDexCacheArrayRelocation(dex_cache->GetResolvedMethods(),
 437                                start + layout.MethodsOffset(),
 438                                dex_cache);
 439     DCHECK_EQ(dex_file->NumFieldIds() != 0u, dex_cache->GetResolvedFields() != nullptr);
 440     AddDexCacheArrayRelocation(dex_cache->GetResolvedFields(),
 441                                start + layout.FieldsOffset(),
 442                                dex_cache);
 443     DCHECK_EQ(dex_file->NumStringIds() != 0u, dex_cache->GetStrings() != nullptr);
 444     AddDexCacheArrayRelocation(dex_cache->GetStrings(), start + layout.StringsOffset(), dex_cache);
 445   }
 446 }
 447
 448 void ImageWriter::AddDexCacheArrayRelocation(void* array, size_t offset, DexCache* dex_cache) {
 449   if (array != nullptr) {
 450     DCHECK(!IsInBootImage(array));
 451     size_t oat_index = GetOatIndexForDexCache(dex_cache);
 452     native_object_relocations_.emplace(array,
 453         NativeObjectRelocation { oat_index, offset, kNativeObjectRelocationTypeDexCacheArray });
 454   }
 455 }
 456
 457 void ImageWriter::AddMethodPointerArray(mirror::PointerArray* arr) {
 458   DCHECK(arr != nullptr);
 459   if (kIsDebugBuild) {
 460     for (size_t i = 0, len = arr->GetLength(); i < len; i++) {
 461       ArtMethod* method = arr->GetElementPtrSize<ArtMethod*>(i, target_ptr_size_);
 462       if (method != nullptr && !method->IsRuntimeMethod()) {
 463         mirror::Class* klass = method->GetDeclaringClass();
 464         CHECK(klass == nullptr || KeepClass(klass))
 465             << PrettyClass(klass) << " should be a kept class";
 466       }
 467     }
 468   }
 469   // kBinArtMethodClean picked arbitrarily, just required to differentiate between ArtFields and
 470   // ArtMethods.
 471   pointer_arrays_.emplace(arr, kBinArtMethodClean);
 472 }
 473
 474 void ImageWriter::AssignImageBinSlot(mirror::Object* object) {
 475   DCHECK(object != nullptr);
 476   size_t object_size = object->SizeOf();
 477
 478   // The magic happens here. We segregate objects into different bins based
 479   // on how likely they are to get dirty at runtime.
 480   //
 481   // Likely-to-dirty objects get packed together into the same bin so that
 482   // at runtime their page dirtiness ratio (how many dirty objects a page has) is
 483   // maximized.
 484   //
 485   // This means more pages will stay either clean or shared dirty (with zygote) and
 486   // the app will use less of its own (private) memory.
 487   Bin bin = kBinRegular;
 488   size_t current_offset = 0u;
 489
 490   if (kBinObjects) {
 491     //
 492     // Changing the bin of an object is purely a memory-use tuning.
 493     // It has no change on runtime correctness.
 494     //
 495     // Memory analysis has determined that the following types of objects get dirtied
 496     // the most:
 497     //
 498     // * Dex cache arrays are stored in a special bin. The arrays for each dex cache have
 499     //   a fixed layout which helps improve generated code (using PC-relative addressing),
 500     //   so we pre-calculate their offsets separately in PrepareDexCacheArraySlots().
 501     //   Since these arrays are huge, most pages do not overlap other objects and it's not
 502     //   really important where they are for the clean/dirty separation. Due to their
 503     //   special PC-relative addressing, we arbitrarily keep them at the end.
 504     // * Class'es which are verified [their clinit runs only at runtime]
 505     //   - classes in general [because their static fields get overwritten]
 506     //   - initialized classes with all-final statics are unlikely to be ever dirty,
 507     //     so bin them separately
 508     // * Art Methods that are:
 509     //   - native [their native entry point is not looked up until runtime]
 510     //   - have declaring classes that aren't initialized
 511     //            [their interpreter/quick entry points are trampolines until the class
 512     //             becomes initialized]
 513     //
 514     // We also assume the following objects get dirtied either never or extremely rarely:
 515     //  * Strings (they are immutable)
 516     //  * Art methods that aren't native and have initialized declared classes
 517     //
 518     // We assume that "regular" bin objects are highly unlikely to become dirtied,
 519     // so packing them together will not result in a noticeably tighter dirty-to-clean ratio.
 520     //
 521     if (object->IsClass()) {
 522       bin = kBinClassVerified;
 523       mirror::Class* klass = object->AsClass();
 524
 525       // Add non-embedded vtable to the pointer array table if there is one.
 526       auto* vtable = klass->GetVTable();
 527       if (vtable != nullptr) {
 528         AddMethodPointerArray(vtable);
 529       }
 530       auto* iftable = klass->GetIfTable();
 531       if (iftable != nullptr) {
 532         for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) {
 533           if (iftable->GetMethodArrayCount(i) > 0) {
 534             AddMethodPointerArray(iftable->GetMethodArray(i));
 535           }
 536         }
 537       }
 538
 539       if (klass->GetStatus() == Class::kStatusInitialized) {
 540         bin = kBinClassInitialized;
 541
 542         // If the class's static fields are all final, put it into a separate bin
 543         // since it's very likely it will stay clean.
 544         uint32_t num_static_fields = klass->NumStaticFields();
 545         if (num_static_fields == 0) {
 546           bin = kBinClassInitializedFinalStatics;
 547         } else {
 548           // Maybe all the statics are final?
 549           bool all_final = true;
 550           for (uint32_t i = 0; i < num_static_fields; ++i) {
 551             ArtField* field = klass->GetStaticField(i);
 552             if (!field->IsFinal()) {
 553               all_final = false;
 554               break;
 555             }
 556           }
 557
 558           if (all_final) {
 559             bin = kBinClassInitializedFinalStatics;
 560           }
 561         }
 562       }
 563     } else if (object->GetClass<kVerifyNone>()->IsStringClass()) {
 564       bin = kBinString;  // Strings are almost always immutable (except for object header).
 565     }  // else bin = kBinRegular
 566   }
 567
 568   size_t oat_index = GetOatIndex(object);
 569   ImageInfo& image_info = GetImageInfo(oat_index);
 570
 571   size_t offset_delta = RoundUp(object_size, kObjectAlignment);  // 64-bit alignment
 572   current_offset = image_info.bin_slot_sizes_[bin];  // How many bytes the current bin is at (aligned).
 573   // Move the current bin size up to accommodate the object we just assigned a bin slot.
 574   image_info.bin_slot_sizes_[bin] += offset_delta;
 575
 576   BinSlot new_bin_slot(bin, current_offset);
 577   SetImageBinSlot(object, new_bin_slot);
 578
 579   ++image_info.bin_slot_count_[bin];
 580
 581   // Grow the image closer to the end by the object we just assigned.
 582   image_info.image_end_ += offset_delta;
 583 }
 584
 585 bool ImageWriter::WillMethodBeDirty(ArtMethod* m) const {
 586   if (m->IsNative()) {
 587     return true;
 588   }
 589   mirror::Class* declaring_class = m->GetDeclaringClass();
 590   // Initialized is highly unlikely to dirty since there's no entry points to mutate.
 591   return declaring_class == nullptr || declaring_class->GetStatus() != Class::kStatusInitialized;
 592 }
 593
 594 bool ImageWriter::IsImageBinSlotAssigned(mirror::Object* object) const {
 595   DCHECK(object != nullptr);
 596
 597   // We always stash the bin slot into a lockword, in the 'forwarding address' state.
 598   // If it's in some other state, then we haven't yet assigned an image bin slot.
 599   if (object->GetLockWord(false).GetState() != LockWord::kForwardingAddress) {
 600     return false;
 601   } else if (kIsDebugBuild) {
 602     LockWord lock_word = object->GetLockWord(false);
 603     size_t offset = lock_word.ForwardingAddress();
 604     BinSlot bin_slot(offset);
 605     size_t oat_index = GetOatIndex(object);
 606     const ImageInfo& image_info = GetImageInfo(oat_index);
 607     DCHECK_LT(bin_slot.GetIndex(), image_info.bin_slot_sizes_[bin_slot.GetBin()])
 608         << "bin slot offset should not exceed the size of that bin";
 609   }
 610   return true;
 611 }
 612
 613 ImageWriter::BinSlot ImageWriter::GetImageBinSlot(mirror::Object* object) const {
 614   DCHECK(object != nullptr);
 615   DCHECK(IsImageBinSlotAssigned(object));
 616
 617   LockWord lock_word = object->GetLockWord(false);
 618   size_t offset = lock_word.ForwardingAddress();  // TODO: ForwardingAddress should be uint32_t
 619   DCHECK_LE(offset, std::numeric_limits<uint32_t>::max());
 620
 621   BinSlot bin_slot(static_cast<uint32_t>(offset));
 622   size_t oat_index = GetOatIndex(object);
 623   const ImageInfo& image_info = GetImageInfo(oat_index);
 624   DCHECK_LT(bin_slot.GetIndex(), image_info.bin_slot_sizes_[bin_slot.GetBin()]);
 625
 626   return bin_slot;
 627 }
 628
 629 bool ImageWriter::AllocMemory() {
 630   for (ImageInfo& image_info : image_infos_) {
 631     ImageSection unused_sections[ImageHeader::kSectionCount];
 632     const size_t length = RoundUp(
 633         image_info.CreateImageSections(target_ptr_size_, unused_sections),
 634         kPageSize);
 635
 636     std::string error_msg;
 637     image_info.image_.reset(MemMap::MapAnonymous("image writer image",
 638                                                  nullptr,
 639                                                  length,
 640                                                  PROT_READ | PROT_WRITE,
 641                                                  false,
 642                                                  false,
 643                                                  &error_msg));
 644     if (UNLIKELY(image_info.image_.get() == nullptr)) {
 645       LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
 646       return false;
 647     }
 648
 649     // Create the image bitmap, only needs to cover mirror object section which is up to image_end_.
 650     CHECK_LE(image_info.image_end_, length);
 651     image_info.image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create(
 652         "image bitmap", image_info.image_->Begin(), RoundUp(image_info.image_end_, kPageSize)));
 653     if (image_info.image_bitmap_.get() == nullptr) {
 654       LOG(ERROR) << "Failed to allocate memory for image bitmap";
 655       return false;
 656     }
 657   }
 658   return true;
 659 }
 660
 661 class ComputeLazyFieldsForClassesVisitor : public ClassVisitor {
 662  public:
 663   bool operator()(Class* c) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
 664     StackHandleScope<1> hs(Thread::Current());
 665     mirror::Class::ComputeName(hs.NewHandle(c));
 666     return true;
 667   }
 668 };
 669
 670 void ImageWriter::ComputeLazyFieldsForImageClasses() {
 671   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
 672   ComputeLazyFieldsForClassesVisitor visitor;
 673   class_linker->VisitClassesWithoutClassesLock(&visitor);
 674 }
 675
 676 static bool IsBootClassLoaderClass(mirror::Class* klass) SHARED_REQUIRES(Locks::mutator_lock_) {
 677   return klass->GetClassLoader() == nullptr;
 678 }
 679
 680 bool ImageWriter::IsBootClassLoaderNonImageClass(mirror::Class* klass) {
 681   return IsBootClassLoaderClass(klass) && !IsInBootImage(klass);
 682 }
 683
 684 bool ImageWriter::PruneAppImageClass(mirror::Class* klass) {
 685   bool early_exit = false;
 686   std::unordered_set<mirror::Class*> visited;
 687   return PruneAppImageClassInternal(klass, &early_exit, &visited);
 688 }
 689
 690 bool ImageWriter::PruneAppImageClassInternal(
 691     mirror::Class* klass,
 692     bool* early_exit,
 693     std::unordered_set<mirror::Class*>* visited) {
 694   DCHECK(early_exit != nullptr);
 695   DCHECK(visited != nullptr);
 696   DCHECK(compile_app_image_);
 697   if (klass == nullptr || IsInBootImage(klass)) {
 698     return false;
 699   }
 700   auto found = prune_class_memo_.find(klass);
 701   if (found != prune_class_memo_.end()) {
 702     // Already computed, return the found value.
 703     return found->second;
 704   }
 705   // Circular dependencies, return false but do not store the result in the memoization table.
 706   if (visited->find(klass) != visited->end()) {
 707     *early_exit = true;
 708     return false;
 709   }
 710   visited->emplace(klass);
 711   bool result = IsBootClassLoaderClass(klass);
 712   std::string temp;
 713   // Prune if not an image class, this handles any broken sets of image classes such as having a
 714   // class in the set but not it's superclass.
 715   result = result || !compiler_driver_.IsImageClass(klass->GetDescriptor(&temp));
 716   bool my_early_exit = false;  // Only for ourselves, ignore caller.
 717   // Remove classes that failed to verify since we don't want to have java.lang.VerifyError in the
 718   // app image.
 719   if (klass->GetStatus() == mirror::Class::kStatusError) {
 720     result = true;
 721   } else {
 722     CHECK(klass->GetVerifyError() == nullptr) << PrettyClass(klass);
 723   }
 724   if (!result) {
 725     // Check interfaces since these wont be visited through VisitReferences.)
 726     mirror::IfTable* if_table = klass->GetIfTable();
 727     for (size_t i = 0, num_interfaces = klass->GetIfTableCount(); i < num_interfaces; ++i) {
 728       result = result || PruneAppImageClassInternal(if_table->GetInterface(i),
 729                                                     &my_early_exit,
 730                                                     visited);
 731     }
 732   }
 733   if (klass->IsObjectArrayClass()) {
 734     result = result || PruneAppImageClassInternal(klass->GetComponentType(),
 735                                                   &my_early_exit,
 736                                                   visited);
 737   }
 738   // Check static fields and their classes.
 739   size_t num_static_fields = klass->NumReferenceStaticFields();
 740   if (num_static_fields != 0 && klass->IsResolved()) {
 741     // Presumably GC can happen when we are cross compiling, it should not cause performance
 742     // problems to do pointer size logic.
 743     MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset(
 744         Runtime::Current()->GetClassLinker()->GetImagePointerSize());
 745     for (size_t i = 0u; i < num_static_fields; ++i) {
 746       mirror::Object* ref = klass->GetFieldObject<mirror::Object>(field_offset);
 747       if (ref != nullptr) {
 748         if (ref->IsClass()) {
 749           result = result || PruneAppImageClassInternal(ref->AsClass(),
 750                                                         &my_early_exit,
 751                                                         visited);
 752         } else {
 753           result = result || PruneAppImageClassInternal(ref->GetClass(),
 754                                                         &my_early_exit,
 755                                                         visited);
 756         }
 757       }
 758       field_offset = MemberOffset(field_offset.Uint32Value() +
 759                                   sizeof(mirror::HeapReference<mirror::Object>));
 760     }
 761   }
 762   result = result || PruneAppImageClassInternal(klass->GetSuperClass(),
 763                                                 &my_early_exit,
 764                                                 visited);
 765   // Erase the element we stored earlier since we are exiting the function.
 766   auto it = visited->find(klass);
 767   DCHECK(it != visited->end());
 768   visited->erase(it);
 769   // Only store result if it is true or none of the calls early exited due to circular
 770   // dependencies. If visited is empty then we are the root caller, in this case the cycle was in
 771   // a child call and we can remember the result.
 772   if (result == true || !my_early_exit || visited->empty()) {
 773     prune_class_memo_[klass] = result;
 774   }
 775   *early_exit |= my_early_exit;
 776   return result;
 777 }
 778
 779 bool ImageWriter::KeepClass(Class* klass) {
 780   if (klass == nullptr) {
 781     return false;
 782   }
 783   if (compile_app_image_ && Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(klass)) {
 784     // Already in boot image, return true.
 785     return true;
 786   }
 787   std::string temp;
 788   if (!compiler_driver_.IsImageClass(klass->GetDescriptor(&temp))) {
 789     return false;
 790   }
 791   if (compile_app_image_) {
 792     // For app images, we need to prune boot loader classes that are not in the boot image since
 793     // these may have already been loaded when the app image is loaded.
 794     // Keep classes in the boot image space since we don't want to re-resolve these.
 795     return !PruneAppImageClass(klass);
 796   }
 797   return true;
 798 }
 799
 800 class NonImageClassesVisitor : public ClassVisitor {
 801  public:
 802   explicit NonImageClassesVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {}
 803
 804   bool operator()(Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
 805     if (!image_writer_->KeepClass(klass)) {
 806       classes_to_prune_.insert(klass);
 807     }
 808     return true;
 809   }
 810
 811   std::unordered_set<mirror::Class*> classes_to_prune_;
 812   ImageWriter* const image_writer_;
 813 };
 814
 815 void ImageWriter::PruneNonImageClasses() {
 816   Runtime* runtime = Runtime::Current();
 817   ClassLinker* class_linker = runtime->GetClassLinker();
 818   Thread* self = Thread::Current();
 819
 820   // Make a list of classes we would like to prune.
 821   NonImageClassesVisitor visitor(this);
 822   class_linker->VisitClasses(&visitor);
 823
 824   // Remove the undesired classes from the class roots.
 825   VLOG(compiler) << "Pruning " << visitor.classes_to_prune_.size() << " classes";
 826   for (mirror::Class* klass : visitor.classes_to_prune_) {
 827     std::string temp;
 828     const char* name = klass->GetDescriptor(&temp);
 829     VLOG(compiler) << "Pruning class " << name;
 830     if (!compile_app_image_) {
 831       DCHECK(IsBootClassLoaderClass(klass));
 832     }
 833     bool result = class_linker->RemoveClass(name, klass->GetClassLoader());
 834     DCHECK(result);
 835   }
 836
 837   // Clear references to removed classes from the DexCaches.
 838   ArtMethod* resolution_method = runtime->GetResolutionMethod();
 839
 840   ScopedAssertNoThreadSuspension sa(self, __FUNCTION__);
 841   ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);  // For ClassInClassTable
 842   ReaderMutexLock mu2(self, *class_linker->DexLock());
 843   for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
 844     if (self->IsJWeakCleared(data.weak_root)) {
 845       continue;
 846     }
 847     mirror::DexCache* dex_cache = self->DecodeJObject(data.weak_root)->AsDexCache();
 848     for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
 849       Class* klass = dex_cache->GetResolvedType(i);
 850       if (klass != nullptr && !KeepClass(klass)) {
 851         dex_cache->SetResolvedType(i, nullptr);
 852       }
 853     }
 854     ArtMethod** resolved_methods = dex_cache->GetResolvedMethods();
 855     for (size_t i = 0, num = dex_cache->NumResolvedMethods(); i != num; ++i) {
 856       ArtMethod* method =
 857           mirror::DexCache::GetElementPtrSize(resolved_methods, i, target_ptr_size_);
 858       DCHECK(method != nullptr) << "Expected resolution method instead of null method";
 859       mirror::Class* declaring_class = method->GetDeclaringClass();
 860       // Copied methods may be held live by a class which was not an image class but have a
 861       // declaring class which is an image class. Set it to the resolution method to be safe and
 862       // prevent dangling pointers.
 863       if (method->IsCopied() || !KeepClass(declaring_class)) {
 864         mirror::DexCache::SetElementPtrSize(resolved_methods,
 865                                             i,
 866                                             resolution_method,
 867                                             target_ptr_size_);
 868       } else {
 869         // Check that the class is still in the classes table.
 870         DCHECK(class_linker->ClassInClassTable(declaring_class)) << "Class "
 871             << PrettyClass(declaring_class) << " not in class linker table";
 872       }
 873     }
 874     ArtField** resolved_fields = dex_cache->GetResolvedFields();
 875     for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
 876       ArtField* field = mirror::DexCache::GetElementPtrSize(resolved_fields, i, target_ptr_size_);
 877       if (field != nullptr && !KeepClass(field->GetDeclaringClass())) {
 878         dex_cache->SetResolvedField(i, nullptr, target_ptr_size_);
 879       }
 880     }
 881     // Clean the dex field. It might have been populated during the initialization phase, but
 882     // contains data only valid during a real run.
 883     dex_cache->SetFieldObject<false>(mirror::DexCache::DexOffset(), nullptr);
 884   }
 885
 886   // Drop the array class cache in the ClassLinker, as these are roots holding those classes live.
 887   class_linker->DropFindArrayClassCache();
 888
 889   // Clear to save RAM.
 890   prune_class_memo_.clear();
 891 }
 892
 893 void ImageWriter::CheckNonImageClassesRemoved() {
 894   if (compiler_driver_.GetImageClasses() != nullptr) {
 895     gc::Heap* heap = Runtime::Current()->GetHeap();
 896     heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
 897   }
 898 }
 899
 900 void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
 901   ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
 902   if (obj->IsClass() && !image_writer->IsInBootImage(obj)) {
 903     Class* klass = obj->AsClass();
 904     if (!image_writer->KeepClass(klass)) {
 905       image_writer->DumpImageClasses();
 906       std::string temp;
 907       CHECK(image_writer->KeepClass(klass)) << klass->GetDescriptor(&temp)
 908                                             << " " << PrettyDescriptor(klass);
 909     }
 910   }
 911 }
 912
 913 void ImageWriter::DumpImageClasses() {
 914   auto image_classes = compiler_driver_.GetImageClasses();
 915   CHECK(image_classes != nullptr);
 916   for (const std::string& image_class : *image_classes) {
 917     LOG(INFO) << " " << image_class;
 918   }
 919 }
 920
 921 mirror::String* ImageWriter::FindInternedString(mirror::String* string) {
 922   Thread* const self = Thread::Current();
 923   for (const ImageInfo& image_info : image_infos_) {
 924     mirror::String* const found = image_info.intern_table_->LookupStrong(self, string);
 925     DCHECK(image_info.intern_table_->LookupWeak(self, string) == nullptr)
 926         << string->ToModifiedUtf8();
 927     if (found != nullptr) {
 928       return found;
 929     }
 930   }
 931   if (compile_app_image_) {
 932     Runtime* const runtime = Runtime::Current();
 933     mirror::String* found = runtime->GetInternTable()->LookupStrong(self, string);
 934     // If we found it in the runtime intern table it could either be in the boot image or interned
 935     // during app image compilation. If it was in the boot image return that, otherwise return null
 936     // since it belongs to another image space.
 937     if (found != nullptr && runtime->GetHeap()->ObjectIsInBootImageSpace(found)) {
 938       return found;
 939     }
 940     DCHECK(runtime->GetInternTable()->LookupWeak(self, string) == nullptr)
 941         << string->ToModifiedUtf8();
 942   }
 943   return nullptr;
 944 }
 945
 946 void ImageWriter::CalculateObjectBinSlots(Object* obj) {
 947   DCHECK(obj != nullptr);
 948   // if it is a string, we want to intern it if its not interned.
 949   if (obj->GetClass()->IsStringClass()) {
 950     size_t oat_index = GetOatIndex(obj);
 951     ImageInfo& image_info = GetImageInfo(oat_index);
 952
 953     // we must be an interned string that was forward referenced and already assigned
 954     if (IsImageBinSlotAssigned(obj)) {
 955       DCHECK_EQ(obj, FindInternedString(obj->AsString()));
 956       return;
 957     }
 958     // Need to check if the string is already interned in another image info so that we don't have
 959     // the intern tables of two different images contain the same string.
 960     mirror::String* interned = FindInternedString(obj->AsString());
 961     if (interned == nullptr) {
 962       // Not in another image space, insert to our table.
 963       interned = image_info.intern_table_->InternStrongImageString(obj->AsString());
 964     }
 965     if (obj != interned) {
 966       if (!IsImageBinSlotAssigned(interned)) {
 967         // interned obj is after us, allocate its location early
 968         AssignImageBinSlot(interned);
 969       }
 970       // point those looking for this object to the interned version.
 971       SetImageBinSlot(obj, GetImageBinSlot(interned));
 972       return;
 973     }
 974     // else (obj == interned), nothing to do but fall through to the normal case
 975   }
 976
 977   AssignImageBinSlot(obj);
 978 }
 979
 980 ObjectArray<Object>* ImageWriter::CreateImageRoots(size_t oat_index) const {
 981   Runtime* runtime = Runtime::Current();
 982   ClassLinker* class_linker = runtime->GetClassLinker();
 983   Thread* self = Thread::Current();
 984   StackHandleScope<3> hs(self);
 985   Handle<Class> object_array_class(hs.NewHandle(
 986       class_linker->FindSystemClass(self, "[Ljava/lang/Object;")));
 987
 988   std::unordered_set<const DexFile*> image_dex_files;
 989   for (auto& pair : dex_file_oat_index_map_) {
 990     const DexFile* image_dex_file = pair.first;
 991     size_t image_oat_index = pair.second;
 992     if (oat_index == image_oat_index) {
 993       image_dex_files.insert(image_dex_file);
 994     }
 995   }
 996
 997   // build an Object[] of all the DexCaches used in the source_space_.
 998   // Since we can't hold the dex lock when allocating the dex_caches
 999   // ObjectArray, we lock the dex lock twice, first to get the number
1000   // of dex caches first and then lock it again to copy the dex
1001   // caches. We check that the number of dex caches does not change.
1002   size_t dex_cache_count = 0;
1003   {
1004     ReaderMutexLock mu(self, *class_linker->DexLock());
1005     // Count number of dex caches not in the boot image.
1006     for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
1007       mirror::DexCache* dex_cache =
1008           down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
1009       const DexFile* dex_file = dex_cache->GetDexFile();
1010       if (!IsInBootImage(dex_cache)) {
1011         dex_cache_count += image_dex_files.find(dex_file) != image_dex_files.end() ? 1u : 0u;
1012       }
1013     }
1014   }
1015   Handle<ObjectArray<Object>> dex_caches(
1016       hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(), dex_cache_count)));
1017   CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array.";
1018   {
1019     ReaderMutexLock mu(self, *class_linker->DexLock());
1020     size_t non_image_dex_caches = 0;
1021     // Re-count number of non image dex caches.
1022     for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
1023       mirror::DexCache* dex_cache =
1024           down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
1025       const DexFile* dex_file = dex_cache->GetDexFile();
1026       if (!IsInBootImage(dex_cache)) {
1027         non_image_dex_caches += image_dex_files.find(dex_file) != image_dex_files.end() ? 1u : 0u;
1028       }
1029     }
1030     CHECK_EQ(dex_cache_count, non_image_dex_caches)
1031         << "The number of non-image dex caches changed.";
1032     size_t i = 0;
1033     for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
1034       mirror::DexCache* dex_cache =
1035           down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
1036       const DexFile* dex_file = dex_cache->GetDexFile();
1037       if (!IsInBootImage(dex_cache) && image_dex_files.find(dex_file) != image_dex_files.end()) {
1038         dex_caches->Set<false>(i, dex_cache);
1039         ++i;
1040       }
1041     }
1042   }
1043
1044   // build an Object[] of the roots needed to restore the runtime
1045   auto image_roots(hs.NewHandle(
1046       ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
1047   image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get());
1048   image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
1049   for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
1050     CHECK(image_roots->Get(i) != nullptr);
1051   }
1052   return image_roots.Get();
1053 }
1054
1055 // Walk instance fields of the given Class. Separate function to allow recursion on the super
1056 // class.
1057 void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
1058   // Visit fields of parent classes first.
1059   StackHandleScope<1> hs(Thread::Current());
1060   Handle<mirror::Class> h_class(hs.NewHandle(klass));
1061   mirror::Class* super = h_class->GetSuperClass();
1062   if (super != nullptr) {
1063     WalkInstanceFields(obj, super);
1064   }
1065   //
1066   size_t num_reference_fields = h_class->NumReferenceInstanceFields();
1067   MemberOffset field_offset = h_class->GetFirstReferenceInstanceFieldOffset();
1068   for (size_t i = 0; i < num_reference_fields; ++i) {
1069     mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
1070     if (value != nullptr) {
1071       WalkFieldsInOrder(value);
1072     }
1073     field_offset = MemberOffset(field_offset.Uint32Value() +
1074                                 sizeof(mirror::HeapReference<mirror::Object>));
1075   }
1076 }
1077
1078 // For an unvisited object, visit it then all its children found via fields.
1079 void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
1080   if (IsInBootImage(obj)) {
1081     // Object is in the image, don't need to fix it up.
1082     return;
1083   }
1084   // Use our own visitor routine (instead of GC visitor) to get better locality between
1085   // an object and its fields
1086   if (!IsImageBinSlotAssigned(obj)) {
1087     // Walk instance fields of all objects
1088     StackHandleScope<2> hs(Thread::Current());
1089     Handle<mirror::Object> h_obj(hs.NewHandle(obj));
1090     Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass()));
1091     // visit the object itself.
1092     CalculateObjectBinSlots(h_obj.Get());
1093     WalkInstanceFields(h_obj.Get(), klass.Get());
1094     // Walk static fields of a Class.
1095     if (h_obj->IsClass()) {
1096       size_t num_reference_static_fields = klass->NumReferenceStaticFields();
1097       MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset(target_ptr_size_);
1098       for (size_t i = 0; i < num_reference_static_fields; ++i) {
1099         mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
1100         if (value != nullptr) {
1101           WalkFieldsInOrder(value);
1102         }
1103         field_offset = MemberOffset(field_offset.Uint32Value() +
1104                                     sizeof(mirror::HeapReference<mirror::Object>));
1105       }
1106       // Visit and assign offsets for fields and field arrays.
1107       auto* as_klass = h_obj->AsClass();
1108       mirror::DexCache* dex_cache = as_klass->GetDexCache();
1109       DCHECK_NE(klass->GetStatus(), mirror::Class::kStatusError);
1110       if (compile_app_image_) {
1111         // Extra sanity, no boot loader classes should be left!
1112         CHECK(!IsBootClassLoaderClass(as_klass)) << PrettyClass(as_klass);
1113       }
1114       LengthPrefixedArray<ArtField>* fields[] = {
1115           as_klass->GetSFieldsPtr(), as_klass->GetIFieldsPtr(),
1116       };
1117       size_t oat_index = GetOatIndexForDexCache(dex_cache);
1118       ImageInfo& image_info = GetImageInfo(oat_index);
1119       {
1120         // Note: This table is only accessed from the image writer, so the lock is technically
1121         // unnecessary.
1122         WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
1123         // Insert in the class table for this iamge.
1124         image_info.class_table_->Insert(as_klass);
1125       }
1126       for (LengthPrefixedArray<ArtField>* cur_fields : fields) {
1127         // Total array length including header.
1128         if (cur_fields != nullptr) {
1129           const size_t header_size = LengthPrefixedArray<ArtField>::ComputeSize(0);
1130           // Forward the entire array at once.
1131           auto it = native_object_relocations_.find(cur_fields);
1132           CHECK(it == native_object_relocations_.end()) << "Field array " << cur_fields
1133                                                   << " already forwarded";
1134           size_t& offset = image_info.bin_slot_sizes_[kBinArtField];
1135           DCHECK(!IsInBootImage(cur_fields));
1136           native_object_relocations_.emplace(
1137               cur_fields,
1138               NativeObjectRelocation {
1139                   oat_index, offset, kNativeObjectRelocationTypeArtFieldArray
1140               });
1141           offset += header_size;
1142           // Forward individual fields so that we can quickly find where they belong.
1143           for (size_t i = 0, count = cur_fields->size(); i < count; ++i) {
1144             // Need to forward arrays separate of fields.
1145             ArtField* field = &cur_fields->At(i);
1146             auto it2 = native_object_relocations_.find(field);
1147             CHECK(it2 == native_object_relocations_.end()) << "Field at index=" << i
1148                 << " already assigned " << PrettyField(field) << " static=" << field->IsStatic();
1149             DCHECK(!IsInBootImage(field));
1150             native_object_relocations_.emplace(
1151                 field,
1152                 NativeObjectRelocation { oat_index, offset, kNativeObjectRelocationTypeArtField });
1153             offset += sizeof(ArtField);
1154           }
1155         }
1156       }
1157       // Visit and assign offsets for methods.
1158       size_t num_methods = as_klass->NumMethods();
1159       if (num_methods != 0) {
1160         bool any_dirty = false;
1161         for (auto& m : as_klass->GetMethods(target_ptr_size_)) {
1162           if (WillMethodBeDirty(&m)) {
1163             any_dirty = true;
1164             break;
1165           }
1166         }
1167         NativeObjectRelocationType type = any_dirty
1168             ? kNativeObjectRelocationTypeArtMethodDirty
1169             : kNativeObjectRelocationTypeArtMethodClean;
1170         Bin bin_type = BinTypeForNativeRelocationType(type);
1171         // Forward the entire array at once, but header first.
1172         const size_t method_alignment = ArtMethod::Alignment(target_ptr_size_);
1173         const size_t method_size = ArtMethod::Size(target_ptr_size_);
1174         const size_t header_size = LengthPrefixedArray<ArtMethod>::ComputeSize(0,
1175                                                                                method_size,
1176                                                                                method_alignment);
1177         LengthPrefixedArray<ArtMethod>* array = as_klass->GetMethodsPtr();
1178         auto it = native_object_relocations_.find(array);
1179         CHECK(it == native_object_relocations_.end())
1180             << "Method array " << array << " already forwarded";
1181         size_t& offset = image_info.bin_slot_sizes_[bin_type];
1182         DCHECK(!IsInBootImage(array));
1183         native_object_relocations_.emplace(array,
1184             NativeObjectRelocation {
1185                 oat_index,
1186                 offset,
1187                 any_dirty ? kNativeObjectRelocationTypeArtMethodArrayDirty
1188                           : kNativeObjectRelocationTypeArtMethodArrayClean });
1189         offset += header_size;
1190         for (auto& m : as_klass->GetMethods(target_ptr_size_)) {
1191           AssignMethodOffset(&m, type, oat_index);
1192         }
1193         (any_dirty ? dirty_methods_ : clean_methods_) += num_methods;
1194       }
1195     } else if (h_obj->IsObjectArray()) {
1196       // Walk elements of an object array.
1197       int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength();
1198       for (int32_t i = 0; i < length; i++) {
1199         mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>();
1200         mirror::Object* value = obj_array->Get(i);
1201         if (value != nullptr) {
1202           WalkFieldsInOrder(value);
1203         }
1204       }
1205     } else if (h_obj->IsClassLoader()) {
1206       // Register the class loader if it has a class table.
1207       // The fake boot class loader should not get registered and we should end up with only one
1208       // class loader.
1209       mirror::ClassLoader* class_loader = h_obj->AsClassLoader();
1210       if (class_loader->GetClassTable() != nullptr) {
1211         class_loaders_.insert(class_loader);
1212       }
1213     }
1214   }
1215 }
1216
1217 void ImageWriter::AssignMethodOffset(ArtMethod* method,
1218                                      NativeObjectRelocationType type,
1219                                      size_t oat_index) {
1220   DCHECK(!IsInBootImage(method));
1221   auto it = native_object_relocations_.find(method);
1222   CHECK(it == native_object_relocations_.end()) << "Method " << method << " already assigned "
1223       << PrettyMethod(method);
1224   ImageInfo& image_info = GetImageInfo(oat_index);
1225   size_t& offset = image_info.bin_slot_sizes_[BinTypeForNativeRelocationType(type)];
1226   native_object_relocations_.emplace(method, NativeObjectRelocation { oat_index, offset, type });
1227   offset += ArtMethod::Size(target_ptr_size_);
1228 }
1229
1230 void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
1231   ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
1232   DCHECK(writer != nullptr);
1233   writer->WalkFieldsInOrder(obj);
1234 }
1235
1236 void ImageWriter::UnbinObjectsIntoOffsetCallback(mirror::Object* obj, void* arg) {
1237   ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
1238   DCHECK(writer != nullptr);
1239   if (!writer->IsInBootImage(obj)) {
1240     writer->UnbinObjectsIntoOffset(obj);
1241   }
1242 }
1243
1244 void ImageWriter::UnbinObjectsIntoOffset(mirror::Object* obj) {
1245   DCHECK(!IsInBootImage(obj));
1246   CHECK(obj != nullptr);
1247
1248   // We know the bin slot, and the total bin sizes for all objects by now,
1249   // so calculate the object's final image offset.
1250
1251   DCHECK(IsImageBinSlotAssigned(obj));
1252   BinSlot bin_slot = GetImageBinSlot(obj);
1253   // Change the lockword from a bin slot into an offset
1254   AssignImageOffset(obj, bin_slot);
1255 }
1256
1257 void ImageWriter::CalculateNewObjectOffsets() {
1258   Thread* const self = Thread::Current();
1259   StackHandleScopeCollection handles(self);
1260   std::vector<Handle<ObjectArray<Object>>> image_roots;
1261   for (size_t i = 0, size = oat_filenames_.size(); i != size; ++i) {
1262     image_roots.push_back(handles.NewHandle(CreateImageRoots(i)));
1263   }
1264
1265   auto* runtime = Runtime::Current();
1266   auto* heap = runtime->GetHeap();
1267
1268   // Leave space for the header, but do not write it yet, we need to
1269   // know where image_roots is going to end up
1270   image_objects_offset_begin_ = RoundUp(sizeof(ImageHeader), kObjectAlignment);  // 64-bit-alignment
1271
1272   // Clear any pre-existing monitors which may have been in the monitor words, assign bin slots.
1273   heap->VisitObjects(WalkFieldsCallback, this);
1274   // Write the image runtime methods.
1275   image_methods_[ImageHeader::kResolutionMethod] = runtime->GetResolutionMethod();
1276   image_methods_[ImageHeader::kImtConflictMethod] = runtime->GetImtConflictMethod();
1277   image_methods_[ImageHeader::kImtUnimplementedMethod] = runtime->GetImtUnimplementedMethod();
1278   image_methods_[ImageHeader::kCalleeSaveMethod] = runtime->GetCalleeSaveMethod(Runtime::kSaveAll);
1279   image_methods_[ImageHeader::kRefsOnlySaveMethod] =
1280       runtime->GetCalleeSaveMethod(Runtime::kRefsOnly);
1281   image_methods_[ImageHeader::kRefsAndArgsSaveMethod] =
1282       runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
1283
1284   // Add room for fake length prefixed array for holding the image methods.
1285   const auto image_method_type = kNativeObjectRelocationTypeArtMethodArrayClean;
1286   auto it = native_object_relocations_.find(&image_method_array_);
1287   CHECK(it == native_object_relocations_.end());
1288   ImageInfo& default_image_info = GetImageInfo(GetDefaultOatIndex());
1289   size_t& offset =
1290       default_image_info.bin_slot_sizes_[BinTypeForNativeRelocationType(image_method_type)];
1291   if (!compile_app_image_) {
1292     native_object_relocations_.emplace(&image_method_array_,
1293         NativeObjectRelocation { GetDefaultOatIndex(), offset, image_method_type });
1294   }
1295   size_t method_alignment = ArtMethod::Alignment(target_ptr_size_);
1296   const size_t array_size = LengthPrefixedArray<ArtMethod>::ComputeSize(
1297       0, ArtMethod::Size(target_ptr_size_), method_alignment);
1298   CHECK_ALIGNED_PARAM(array_size, method_alignment);
1299   offset += array_size;
1300   for (auto* m : image_methods_) {
1301     CHECK(m != nullptr);
1302     CHECK(m->IsRuntimeMethod());
1303     DCHECK_EQ(compile_app_image_, IsInBootImage(m)) << "Trampolines should be in boot image";
1304     if (!IsInBootImage(m)) {
1305       AssignMethodOffset(m, kNativeObjectRelocationTypeArtMethodClean, GetDefaultOatIndex());
1306     }
1307   }
1308   // Calculate size of the dex cache arrays slot and prepare offsets.
1309   PrepareDexCacheArraySlots();
1310
1311   // Calculate the sizes of the intern tables and class tables.
1312   for (ImageInfo& image_info : image_infos_) {
1313     // Calculate how big the intern table will be after being serialized.
1314     InternTable* const intern_table = image_info.intern_table_.get();
1315     CHECK_EQ(intern_table->WeakSize(), 0u) << " should have strong interned all the strings";
1316     image_info.intern_table_bytes_ = intern_table->WriteToMemory(nullptr);
1317     // Calculate the size of the class table.
1318     ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);
1319     image_info.class_table_bytes_ += image_info.class_table_->WriteToMemory(nullptr);
1320   }
1321
1322   // Calculate bin slot offsets.
1323   for (ImageInfo& image_info : image_infos_) {
1324     size_t bin_offset = image_objects_offset_begin_;
1325     for (size_t i = 0; i != kBinSize; ++i) {
1326       image_info.bin_slot_offsets_[i] = bin_offset;
1327       bin_offset += image_info.bin_slot_sizes_[i];
1328       if (i == kBinArtField) {
1329         static_assert(kBinArtField + 1 == kBinArtMethodClean, "Methods follow fields.");
1330         static_assert(alignof(ArtField) == 4u, "ArtField alignment is 4.");
1331         DCHECK_ALIGNED(bin_offset, 4u);
1332         DCHECK(method_alignment == 4u || method_alignment == 8u);
1333         bin_offset = RoundUp(bin_offset, method_alignment);
1334       }
1335     }
1336     // NOTE: There may be additional padding between the bin slots and the intern table.
1337     DCHECK_EQ(image_info.image_end_,
1338               GetBinSizeSum(image_info, kBinMirrorCount) + image_objects_offset_begin_);
1339   }
1340
1341   // Calculate image offsets.
1342   size_t image_offset = 0;
1343   for (ImageInfo& image_info : image_infos_) {
1344     image_info.image_begin_ = global_image_begin_ + image_offset;
1345     image_info.image_offset_ = image_offset;
1346     ImageSection unused_sections[ImageHeader::kSectionCount];
1347     image_info.image_size_ = RoundUp(
1348         image_info.CreateImageSections(target_ptr_size_, unused_sections),
1349         kPageSize);
1350     // There should be no gaps until the next image.
1351     image_offset += image_info.image_size_;
1352   }
1353
1354   // Transform each object's bin slot into an offset which will be used to do the final copy.
1355   heap->VisitObjects(UnbinObjectsIntoOffsetCallback, this);
1356
1357   // DCHECK_EQ(image_end_, GetBinSizeSum(kBinMirrorCount) + image_objects_offset_begin_);
1358
1359   size_t i = 0;
1360   for (ImageInfo& image_info : image_infos_) {
1361     image_info.image_roots_address_ = PointerToLowMemUInt32(GetImageAddress(image_roots[i].Get()));
1362     i++;
1363   }
1364
1365   // Update the native relocations by adding their bin sums.
1366   for (auto& pair : native_object_relocations_) {
1367     NativeObjectRelocation& relocation = pair.second;
1368     Bin bin_type = BinTypeForNativeRelocationType(relocation.type);
1369     ImageInfo& image_info = GetImageInfo(relocation.oat_index);
1370     relocation.offset += image_info.bin_slot_offsets_[bin_type];
1371   }
1372
1373   // Note that image_info.image_end_ is left at end of used mirror object section.
1374 }
1375
1376 size_t ImageWriter::ImageInfo::CreateImageSections(size_t target_ptr_size,
1377                                                    ImageSection* out_sections) const {
1378   DCHECK(out_sections != nullptr);
1379   // Objects section
1380   auto* objects_section = &out_sections[ImageHeader::kSectionObjects];
1381   *objects_section = ImageSection(0u, image_end_);
1382   size_t cur_pos = objects_section->End();
1383   // Add field section.
1384   auto* field_section = &out_sections[ImageHeader::kSectionArtFields];
1385   *field_section = ImageSection(cur_pos, bin_slot_sizes_[kBinArtField]);
1386   CHECK_EQ(bin_slot_offsets_[kBinArtField], field_section->Offset());
1387   cur_pos = field_section->End();
1388   // Round up to the alignment the required by the method section.
1389   cur_pos = RoundUp(cur_pos, ArtMethod::Alignment(target_ptr_size));
1390   // Add method section.
1391   auto* methods_section = &out_sections[ImageHeader::kSectionArtMethods];
1392   *methods_section = ImageSection(cur_pos,
1393                                   bin_slot_sizes_[kBinArtMethodClean] +
1394                                       bin_slot_sizes_[kBinArtMethodDirty]);
1395   CHECK_EQ(bin_slot_offsets_[kBinArtMethodClean], methods_section->Offset());
1396   cur_pos = methods_section->End();
1397   // Add dex cache arrays section.
1398   auto* dex_cache_arrays_section = &out_sections[ImageHeader::kSectionDexCacheArrays];
1399   *dex_cache_arrays_section = ImageSection(cur_pos, bin_slot_sizes_[kBinDexCacheArray]);
1400   CHECK_EQ(bin_slot_offsets_[kBinDexCacheArray], dex_cache_arrays_section->Offset());
1401   cur_pos = dex_cache_arrays_section->End();
1402   // Round up to the alignment the string table expects. See HashSet::WriteToMemory.
1403   cur_pos = RoundUp(cur_pos, sizeof(uint64_t));
1404   // Calculate the size of the interned strings.
1405   auto* interned_strings_section = &out_sections[ImageHeader::kSectionInternedStrings];
1406   *interned_strings_section = ImageSection(cur_pos, intern_table_bytes_);
1407   cur_pos = interned_strings_section->End();
1408   // Round up to the alignment the class table expects. See HashSet::WriteToMemory.
1409   cur_pos = RoundUp(cur_pos, sizeof(uint64_t));
1410   // Calculate the size of the class table section.
1411   auto* class_table_section = &out_sections[ImageHeader::kSectionClassTable];
1412   *class_table_section = ImageSection(cur_pos, class_table_bytes_);
1413   cur_pos = class_table_section->End();
1414   // Image end goes right before the start of the image bitmap.
1415   return cur_pos;
1416 }
1417
1418 void ImageWriter::CreateHeader(size_t oat_index) {
1419   ImageInfo& image_info = GetImageInfo(oat_index);
1420   const uint8_t* oat_file_begin = image_info.oat_file_begin_;
1421   const uint8_t* oat_file_end = oat_file_begin + image_info.oat_loaded_size_;
1422   const uint8_t* oat_data_end = image_info.oat_data_begin_ + image_info.oat_size_;
1423
1424   // Create the image sections.
1425   ImageSection sections[ImageHeader::kSectionCount];
1426   const size_t image_end = image_info.CreateImageSections(target_ptr_size_, sections);
1427
1428   // Finally bitmap section.
1429   const size_t bitmap_bytes = image_info.image_bitmap_->Size();
1430   auto* bitmap_section = &sections[ImageHeader::kSectionImageBitmap];
1431   *bitmap_section = ImageSection(RoundUp(image_end, kPageSize), RoundUp(bitmap_bytes, kPageSize));
1432   if (VLOG_IS_ON(compiler)) {
1433     LOG(INFO) << "Creating header for " << oat_filenames_[oat_index];
1434     size_t idx = 0;
1435     for (const ImageSection& section : sections) {
1436       LOG(INFO) << static_cast<ImageHeader::ImageSections>(idx) << " " << section;
1437       ++idx;
1438     }
1439     LOG(INFO) << "Methods: clean=" << clean_methods_ << " dirty=" << dirty_methods_;
1440     LOG(INFO) << "Image roots address=" << std::hex << image_info.image_roots_address_ << std::dec;
1441     LOG(INFO) << "Image begin=" << std::hex << reinterpret_cast<uintptr_t>(global_image_begin_)
1442               << " Image offset=" << image_info.image_offset_ << std::dec;
1443     LOG(INFO) << "Oat file begin=" << std::hex << reinterpret_cast<uintptr_t>(oat_file_begin)
1444               << " Oat data begin=" << reinterpret_cast<uintptr_t>(image_info.oat_data_begin_)
1445               << " Oat data end=" << reinterpret_cast<uintptr_t>(oat_data_end)
1446               << " Oat file end=" << reinterpret_cast<uintptr_t>(oat_file_end);
1447   }
1448   // Store boot image info for app image so that we can relocate.
1449   uint32_t boot_image_begin = 0;
1450   uint32_t boot_image_end = 0;
1451   uint32_t boot_oat_begin = 0;
1452   uint32_t boot_oat_end = 0;
1453   gc::Heap* const heap = Runtime::Current()->GetHeap();
1454   heap->GetBootImagesSize(&boot_image_begin, &boot_image_end, &boot_oat_begin, &boot_oat_end);
1455
1456   // Create the header, leave 0 for data size since we will fill this in as we are writing the
1457   // image.
1458   new (image_info.image_->Begin()) ImageHeader(PointerToLowMemUInt32(image_info.image_begin_),
1459                                                image_end,
1460                                                sections,
1461                                                image_info.image_roots_address_,
1462                                                image_info.oat_checksum_,
1463                                                PointerToLowMemUInt32(oat_file_begin),
1464                                                PointerToLowMemUInt32(image_info.oat_data_begin_),
1465                                                PointerToLowMemUInt32(oat_data_end),
1466                                                PointerToLowMemUInt32(oat_file_end),
1467                                                boot_image_begin,
1468                                                boot_image_end - boot_image_begin,
1469                                                boot_oat_begin,
1470                                                boot_oat_end - boot_oat_begin,
1471                                                target_ptr_size_,
1472                                                compile_pic_,
1473                                                /*is_pic*/compile_app_image_,
1474                                                image_storage_mode_,
1475                                                /*data_size*/0u);
1476 }
1477
1478 ArtMethod* ImageWriter::GetImageMethodAddress(ArtMethod* method) {
1479   auto it = native_object_relocations_.find(method);
1480   CHECK(it != native_object_relocations_.end()) << PrettyMethod(method) << " @ " << method;
1481   size_t oat_index = GetOatIndex(method->GetDexCache());
1482   ImageInfo& image_info = GetImageInfo(oat_index);
1483   CHECK_GE(it->second.offset, image_info.image_end_) << "ArtMethods should be after Objects";
1484   return reinterpret_cast<ArtMethod*>(image_info.image_begin_ + it->second.offset);
1485 }
1486
1487 class FixupRootVisitor : public RootVisitor {
1488  public:
1489   explicit FixupRootVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {
1490   }
1491
1492   void VisitRoots(mirror::Object*** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED)
1493       OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
1494     for (size_t i = 0; i < count; ++i) {
1495       *roots[i] = image_writer_->GetImageAddress(*roots[i]);
1496     }
1497   }
1498
1499   void VisitRoots(mirror::CompressedReference<mirror::Object>** roots, size_t count,
1500                   const RootInfo& info ATTRIBUTE_UNUSED)
1501       OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
1502     for (size_t i = 0; i < count; ++i) {
1503       roots[i]->Assign(image_writer_->GetImageAddress(roots[i]->AsMirrorPtr()));
1504     }
1505   }
1506
1507  private:
1508   ImageWriter* const image_writer_;
1509 };
1510
1511 void ImageWriter::CopyAndFixupNativeData(size_t oat_index) {
1512   ImageInfo& image_info = GetImageInfo(oat_index);
1513   // Copy ArtFields and methods to their locations and update the array for convenience.
1514   for (auto& pair : native_object_relocations_) {
1515     NativeObjectRelocation& relocation = pair.second;
1516     // Only work with fields and methods that are in the current oat file.
1517     if (relocation.oat_index != oat_index) {
1518       continue;
1519     }
1520     auto* dest = image_info.image_->Begin() + relocation.offset;
1521     DCHECK_GE(dest, image_info.image_->Begin() + image_info.image_end_);
1522     DCHECK(!IsInBootImage(pair.first));
1523     switch (relocation.type) {
1524       case kNativeObjectRelocationTypeArtField: {
1525         memcpy(dest, pair.first, sizeof(ArtField));
1526         reinterpret_cast<ArtField*>(dest)->SetDeclaringClass(
1527             GetImageAddress(reinterpret_cast<ArtField*>(pair.first)->GetDeclaringClass()));
1528         break;
1529       }
1530       case kNativeObjectRelocationTypeArtMethodClean:
1531       case kNativeObjectRelocationTypeArtMethodDirty: {
1532         CopyAndFixupMethod(reinterpret_cast<ArtMethod*>(pair.first),
1533                            reinterpret_cast<ArtMethod*>(dest),
1534                            image_info);
1535         break;
1536       }
1537       // For arrays, copy just the header since the elements will get copied by their corresponding
1538       // relocations.
1539       case kNativeObjectRelocationTypeArtFieldArray: {
1540         memcpy(dest, pair.first, LengthPrefixedArray<ArtField>::ComputeSize(0));
1541         break;
1542       }
1543       case kNativeObjectRelocationTypeArtMethodArrayClean:
1544       case kNativeObjectRelocationTypeArtMethodArrayDirty: {
1545         size_t size = ArtMethod::Size(target_ptr_size_);
1546         size_t alignment = ArtMethod::Alignment(target_ptr_size_);
1547         memcpy(dest, pair.first, LengthPrefixedArray<ArtMethod>::ComputeSize(0, size, alignment));
1548         // Clear padding to avoid non-deterministic data in the image (and placate valgrind).
1549         reinterpret_cast<LengthPrefixedArray<ArtMethod>*>(dest)->ClearPadding(size, alignment);
1550         break;
1551       }
1552       case kNativeObjectRelocationTypeDexCacheArray:
1553         // Nothing to copy here, everything is done in FixupDexCache().
1554         break;
1555     }
1556   }
1557   // Fixup the image method roots.
1558   auto* image_header = reinterpret_cast<ImageHeader*>(image_info.image_->Begin());
1559   const ImageSection& methods_section = image_header->GetMethodsSection();
1560   for (size_t i = 0; i < ImageHeader::kImageMethodsCount; ++i) {
1561     ArtMethod* method = image_methods_[i];
1562     CHECK(method != nullptr);
1563     // Only place runtime methods in the image of the default oat file.
1564     if (method->IsRuntimeMethod() && oat_index != GetDefaultOatIndex()) {
1565       continue;
1566     }
1567     if (!IsInBootImage(method)) {
1568       auto it = native_object_relocations_.find(method);
1569       CHECK(it != native_object_relocations_.end()) << "No forwarding for " << PrettyMethod(method);
1570       NativeObjectRelocation& relocation = it->second;
1571       CHECK(methods_section.Contains(relocation.offset)) << relocation.offset << " not in "
1572           << methods_section;
1573       CHECK(relocation.IsArtMethodRelocation()) << relocation.type;
1574       method = reinterpret_cast<ArtMethod*>(global_image_begin_ + it->second.offset);
1575     }
1576     image_header->SetImageMethod(static_cast<ImageHeader::ImageMethod>(i), method);
1577   }
1578   FixupRootVisitor root_visitor(this);
1579
1580   // Write the intern table into the image.
1581   if (image_info.intern_table_bytes_ > 0) {
1582     const ImageSection& intern_table_section = image_header->GetImageSection(
1583         ImageHeader::kSectionInternedStrings);
1584     InternTable* const intern_table = image_info.intern_table_.get();
1585     uint8_t* const intern_table_memory_ptr =
1586         image_info.image_->Begin() + intern_table_section.Offset();
1587     const size_t intern_table_bytes = intern_table->WriteToMemory(intern_table_memory_ptr);
1588     CHECK_EQ(intern_table_bytes, image_info.intern_table_bytes_);
1589     // Fixup the pointers in the newly written intern table to contain image addresses.
1590     InternTable temp_intern_table;
1591     // Note that we require that ReadFromMemory does not make an internal copy of the elements so that
1592     // the VisitRoots() will update the memory directly rather than the copies.
1593     // This also relies on visit roots not doing any verification which could fail after we update
1594     // the roots to be the image addresses.
1595     temp_intern_table.AddTableFromMemory(intern_table_memory_ptr);
1596     CHECK_EQ(temp_intern_table.Size(), intern_table->Size());
1597     temp_intern_table.VisitRoots(&root_visitor, kVisitRootFlagAllRoots);
1598   }
1599   // Write the class table(s) into the image. class_table_bytes_ may be 0 if there are multiple
1600   // class loaders. Writing multiple class tables into the image is currently unsupported.
1601   if (image_info.class_table_bytes_ > 0u) {
1602     const ImageSection& class_table_section = image_header->GetImageSection(
1603         ImageHeader::kSectionClassTable);
1604     uint8_t* const class_table_memory_ptr =
1605         image_info.image_->Begin() + class_table_section.Offset();
1606     ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
1607
1608     ClassTable* table = image_info.class_table_.get();
1609     CHECK(table != nullptr);
1610     const size_t class_table_bytes = table->WriteToMemory(class_table_memory_ptr);
1611     CHECK_EQ(class_table_bytes, image_info.class_table_bytes_);
1612     // Fixup the pointers in the newly written class table to contain image addresses. See
1613     // above comment for intern tables.
1614     ClassTable temp_class_table;
1615     temp_class_table.ReadFromMemory(class_table_memory_ptr);
1616     CHECK_EQ(temp_class_table.NumZygoteClasses(), table->NumNonZygoteClasses() +
1617              table->NumZygoteClasses());
1618     BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor(&root_visitor,
1619                                                                     RootInfo(kRootUnknown));
1620     temp_class_table.VisitRoots(buffered_visitor);
1621   }
1622 }
1623
1624 void ImageWriter::CopyAndFixupObjects() {
1625   gc::Heap* heap = Runtime::Current()->GetHeap();
1626   heap->VisitObjects(CopyAndFixupObjectsCallback, this);
1627   // Fix up the object previously had hash codes.
1628   for (const auto& hash_pair : saved_hashcode_map_) {
1629     Object* obj = hash_pair.first;
1630     DCHECK_EQ(obj->GetLockWord<kVerifyNone>(false).ReadBarrierState(), 0U);
1631     obj->SetLockWord<kVerifyNone>(LockWord::FromHashCode(hash_pair.second, 0U), false);
1632   }
1633   saved_hashcode_map_.clear();
1634 }
1635
1636 void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
1637   DCHECK(obj != nullptr);
1638   DCHECK(arg != nullptr);
1639   reinterpret_cast<ImageWriter*>(arg)->CopyAndFixupObject(obj);
1640 }
1641
1642 void ImageWriter::FixupPointerArray(mirror::Object* dst, mirror::PointerArray* arr,
1643                                     mirror::Class* klass, Bin array_type) {
1644   CHECK(klass->IsArrayClass());
1645   CHECK(arr->IsIntArray() || arr->IsLongArray()) << PrettyClass(klass) << " " << arr;
1646   // Fixup int and long pointers for the ArtMethod or ArtField arrays.
1647   const size_t num_elements = arr->GetLength();
1648   dst->SetClass(GetImageAddress(arr->GetClass()));
1649   auto* dest_array = down_cast<mirror::PointerArray*>(dst);
1650   for (size_t i = 0, count = num_elements; i < count; ++i) {
1651     void* elem = arr->GetElementPtrSize<void*>(i, target_ptr_size_);
1652     if (elem != nullptr && !IsInBootImage(elem)) {
1653       auto it = native_object_relocations_.find(elem);
1654       if (UNLIKELY(it == native_object_relocations_.end())) {
1655         if (it->second.IsArtMethodRelocation()) {
1656           auto* method = reinterpret_cast<ArtMethod*>(elem);
1657           LOG(FATAL) << "No relocation entry for ArtMethod " << PrettyMethod(method) << " @ "
1658               << method << " idx=" << i << "/" << num_elements << " with declaring class "
1659               << PrettyClass(method->GetDeclaringClass());
1660         } else {
1661           CHECK_EQ(array_type, kBinArtField);
1662           auto* field = reinterpret_cast<ArtField*>(elem);
1663           LOG(FATAL) << "No relocation entry for ArtField " << PrettyField(field) << " @ "
1664               << field << " idx=" << i << "/" << num_elements << " with declaring class "
1665               << PrettyClass(field->GetDeclaringClass());
1666         }
1667         UNREACHABLE();
1668       } else {
1669         ImageInfo& image_info = GetImageInfo(it->second.oat_index);
1670         elem = image_info.image_begin_ + it->second.offset;
1671       }
1672     }
1673     dest_array->SetElementPtrSize<false, true>(i, elem, target_ptr_size_);
1674   }
1675 }
1676
1677 void ImageWriter::CopyAndFixupObject(Object* obj) {
1678   if (IsInBootImage(obj)) {
1679     return;
1680   }
1681   size_t offset = GetImageOffset(obj);
1682   size_t oat_index = GetOatIndex(obj);
1683   ImageInfo& image_info = GetImageInfo(oat_index);
1684   auto* dst = reinterpret_cast<Object*>(image_info.image_->Begin() + offset);
1685   DCHECK_LT(offset, image_info.image_end_);
1686   const auto* src = reinterpret_cast<const uint8_t*>(obj);
1687
1688   image_info.image_bitmap_->Set(dst);  // Mark the obj as live.
1689
1690   const size_t n = obj->SizeOf();
1691   DCHECK_LE(offset + n, image_info.image_->Size());
1692   memcpy(dst, src, n);
1693
1694   // Write in a hash code of objects which have inflated monitors or a hash code in their monitor
1695   // word.
1696   const auto it = saved_hashcode_map_.find(obj);
1697   dst->SetLockWord(it != saved_hashcode_map_.end() ?
1698       LockWord::FromHashCode(it->second, 0u) : LockWord::Default(), false);
1699   FixupObject(obj, dst);
1700 }
1701
1702 // Rewrite all the references in the copied object to point to their image address equivalent
1703 class FixupVisitor {
1704  public:
1705   FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
1706   }
1707
1708   // Ignore class roots since we don't have a way to map them to the destination. These are handled
1709   // with other logic.
1710   void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root ATTRIBUTE_UNUSED)
1711       const {}
1712   void VisitRoot(mirror::CompressedReference<mirror::Object>* root ATTRIBUTE_UNUSED) const {}
1713
1714
1715   void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const
1716       REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
1717     Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset);
1718     // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
1719     // image.
1720     copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
1721         offset,
1722         image_writer_->GetImageAddress(ref));
1723   }
1724
1725   // java.lang.ref.Reference visitor.
1726   void operator()(mirror::Class* klass ATTRIBUTE_UNUSED, mirror::Reference* ref) const
1727       SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) {
1728     copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
1729         mirror::Reference::ReferentOffset(),
1730         image_writer_->GetImageAddress(ref->GetReferent()));
1731   }
1732
1733  protected:
1734   ImageWriter* const image_writer_;
1735   mirror::Object* const copy_;
1736 };
1737
1738 class FixupClassVisitor FINAL : public FixupVisitor {
1739  public:
1740   FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) {
1741   }
1742
1743   void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const
1744       REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
1745     DCHECK(obj->IsClass());
1746     FixupVisitor::operator()(obj, offset, /*is_static*/false);
1747   }
1748
1749   void operator()(mirror::Class* klass ATTRIBUTE_UNUSED,
1750                   mirror::Reference* ref ATTRIBUTE_UNUSED) const
1751       SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) {
1752     LOG(FATAL) << "Reference not expected here.";
1753   }
1754 };
1755
1756 uintptr_t ImageWriter::NativeOffsetInImage(void* obj) {
1757   DCHECK(obj != nullptr);
1758   DCHECK(!IsInBootImage(obj));
1759   auto it = native_object_relocations_.find(obj);
1760   CHECK(it != native_object_relocations_.end()) << obj << " spaces "
1761       << Runtime::Current()->GetHeap()->DumpSpaces();
1762   const NativeObjectRelocation& relocation = it->second;
1763   return relocation.offset;
1764 }
1765
1766 template <typename T>
1767 T* ImageWriter::NativeLocationInImage(T* obj) {
1768   if (obj == nullptr || IsInBootImage(obj)) {
1769     return obj;
1770   } else {
1771     auto it = native_object_relocations_.find(obj);
1772     CHECK(it != native_object_relocations_.end()) << obj << " spaces "
1773         << Runtime::Current()->GetHeap()->DumpSpaces();
1774     const NativeObjectRelocation& relocation = it->second;
1775     ImageInfo& image_info = GetImageInfo(relocation.oat_index);
1776     return reinterpret_cast<T*>(image_info.image_begin_ + relocation.offset);
1777   }
1778 }
1779
1780 template <typename T>
1781 T* ImageWriter::NativeCopyLocation(T* obj, mirror::DexCache* dex_cache) {
1782   if (obj == nullptr || IsInBootImage(obj)) {
1783     return obj;
1784   } else {
1785     size_t oat_index = GetOatIndexForDexCache(dex_cache);
1786     ImageInfo& image_info = GetImageInfo(oat_index);
1787     return reinterpret_cast<T*>(image_info.image_->Begin() + NativeOffsetInImage(obj));
1788   }
1789 }
1790
1791 class NativeLocationVisitor {
1792  public:
1793   explicit NativeLocationVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {}
1794
1795   template <typename T>
1796   T* operator()(T* ptr) const SHARED_REQUIRES(Locks::mutator_lock_) {
1797     return image_writer_->NativeLocationInImage(ptr);
1798   }
1799
1800  private:
1801   ImageWriter* const image_writer_;
1802 };
1803
1804 void ImageWriter::FixupClass(mirror::Class* orig, mirror::Class* copy) {
1805   orig->FixupNativePointers(copy, target_ptr_size_, NativeLocationVisitor(this));
1806   FixupClassVisitor visitor(this, copy);
1807   static_cast<mirror::Object*>(orig)->VisitReferences(visitor, visitor);
1808
1809   // Remove the clinitThreadId. This is required for image determinism.
1810   copy->SetClinitThreadId(static_cast<pid_t>(0));
1811 }
1812
1813 void ImageWriter::FixupObject(Object* orig, Object* copy) {
1814   DCHECK(orig != nullptr);
1815   DCHECK(copy != nullptr);
1816   if (kUseBakerOrBrooksReadBarrier) {
1817     orig->AssertReadBarrierPointer();
1818     if (kUseBrooksReadBarrier) {
1819       // Note the address 'copy' isn't the same as the image address of 'orig'.
1820       copy->SetReadBarrierPointer(GetImageAddress(orig));
1821       DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig));
1822     }
1823   }
1824   auto* klass = orig->GetClass();
1825   if (klass->IsIntArrayClass() || klass->IsLongArrayClass()) {
1826     // Is this a native pointer array?
1827     auto it = pointer_arrays_.find(down_cast<mirror::PointerArray*>(orig));
1828     if (it != pointer_arrays_.end()) {
1829       // Should only need to fixup every pointer array exactly once.
1830       FixupPointerArray(copy, down_cast<mirror::PointerArray*>(orig), klass, it->second);
1831       pointer_arrays_.erase(it);
1832       return;
1833     }
1834   }
1835   if (orig->IsClass()) {
1836     FixupClass(orig->AsClass<kVerifyNone>(), down_cast<mirror::Class*>(copy));
1837   } else {
1838     if (klass == mirror::Method::StaticClass() || klass == mirror::Constructor::StaticClass()) {
1839       // Need to go update the ArtMethod.
1840       auto* dest = down_cast<mirror::AbstractMethod*>(copy);
1841       auto* src = down_cast<mirror::AbstractMethod*>(orig);
1842       ArtMethod* src_method = src->GetArtMethod();
1843       auto it = native_object_relocations_.find(src_method);
1844       CHECK(it != native_object_relocations_.end())
1845           << "Missing relocation for AbstractMethod.artMethod " << PrettyMethod(src_method);
1846       dest->SetArtMethod(
1847           reinterpret_cast<ArtMethod*>(global_image_begin_ + it->second.offset));
1848     } else if (!klass->IsArrayClass()) {
1849       ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
1850       if (klass == class_linker->GetClassRoot(ClassLinker::kJavaLangDexCache)) {
1851         FixupDexCache(down_cast<mirror::DexCache*>(orig), down_cast<mirror::DexCache*>(copy));
1852       } else if (klass->IsClassLoaderClass()) {
1853         mirror::ClassLoader* copy_loader = down_cast<mirror::ClassLoader*>(copy);
1854         // If src is a ClassLoader, set the class table to null so that it gets recreated by the
1855         // ClassLoader.
1856         copy_loader->SetClassTable(nullptr);
1857         // Also set allocator to null to be safe. The allocator is created when we create the class
1858         // table. We also never expect to unload things in the image since they are held live as
1859         // roots.
1860         copy_loader->SetAllocator(nullptr);
1861       }
1862     }
1863     FixupVisitor visitor(this, copy);
1864     orig->VisitReferences(visitor, visitor);
1865   }
1866 }
1867
1868
1869 class ImageAddressVisitor {
1870  public:
1871   explicit ImageAddressVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {}
1872
1873   template <typename T>
1874   T* operator()(T* ptr) const SHARED_REQUIRES(Locks::mutator_lock_) {
1875     return image_writer_->GetImageAddress(ptr);
1876   }
1877
1878  private:
1879   ImageWriter* const image_writer_;
1880 };
1881
1882
1883 void ImageWriter::FixupDexCache(mirror::DexCache* orig_dex_cache,
1884                                 mirror::DexCache* copy_dex_cache) {
1885   // Though the DexCache array fields are usually treated as native pointers, we set the full
1886   // 64-bit values here, clearing the top 32 bits for 32-bit targets. The zero-extension is
1887   // done by casting to the unsigned type uintptr_t before casting to int64_t, i.e.
1888   //     static_cast<int64_t>(reinterpret_cast<uintptr_t>(image_begin_ + offset))).
1889   GcRoot<mirror::String>* orig_strings = orig_dex_cache->GetStrings();
1890   if (orig_strings != nullptr) {
1891     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::StringsOffset(),
1892                                                NativeLocationInImage(orig_strings),
1893                                                /*pointer size*/8u);
1894     orig_dex_cache->FixupStrings(NativeCopyLocation(orig_strings, orig_dex_cache),
1895                                  ImageAddressVisitor(this));
1896   }
1897   GcRoot<mirror::Class>* orig_types = orig_dex_cache->GetResolvedTypes();
1898   if (orig_types != nullptr) {
1899     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::ResolvedTypesOffset(),
1900                                                NativeLocationInImage(orig_types),
1901                                                /*pointer size*/8u);
1902     orig_dex_cache->FixupResolvedTypes(NativeCopyLocation(orig_types, orig_dex_cache),
1903                                        ImageAddressVisitor(this));
1904   }
1905   ArtMethod** orig_methods = orig_dex_cache->GetResolvedMethods();
1906   if (orig_methods != nullptr) {
1907     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::ResolvedMethodsOffset(),
1908                                                NativeLocationInImage(orig_methods),
1909                                                /*pointer size*/8u);
1910     ArtMethod** copy_methods = NativeCopyLocation(orig_methods, orig_dex_cache);
1911     for (size_t i = 0, num = orig_dex_cache->NumResolvedMethods(); i != num; ++i) {
1912       ArtMethod* orig = mirror::DexCache::GetElementPtrSize(orig_methods, i, target_ptr_size_);
1913       // NativeLocationInImage also handles runtime methods since these have relocation info.
1914       ArtMethod* copy = NativeLocationInImage(orig);
1915       mirror::DexCache::SetElementPtrSize(copy_methods, i, copy, target_ptr_size_);
1916     }
1917   }
1918   ArtField** orig_fields = orig_dex_cache->GetResolvedFields();
1919   if (orig_fields != nullptr) {
1920     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::ResolvedFieldsOffset(),
1921                                                NativeLocationInImage(orig_fields),
1922                                                /*pointer size*/8u);
1923     ArtField** copy_fields = NativeCopyLocation(orig_fields, orig_dex_cache);
1924     for (size_t i = 0, num = orig_dex_cache->NumResolvedFields(); i != num; ++i) {
1925       ArtField* orig = mirror::DexCache::GetElementPtrSize(orig_fields, i, target_ptr_size_);
1926       ArtField* copy = NativeLocationInImage(orig);
1927       mirror::DexCache::SetElementPtrSize(copy_fields, i, copy, target_ptr_size_);
1928     }
1929   }
1930
1931   // Remove the DexFile pointers. They will be fixed up when the runtime loads the oat file. Leaving
1932   // compiler pointers in here will make the output non-deterministic.
1933   copy_dex_cache->SetDexFile(nullptr);
1934 }
1935
1936 const uint8_t* ImageWriter::GetOatAddress(OatAddress type) const {
1937   DCHECK_LT(type, kOatAddressCount);
1938   // If we are compiling an app image, we need to use the stubs of the boot image.
1939   if (compile_app_image_) {
1940     // Use the current image pointers.
1941     const std::vector<gc::space::ImageSpace*>& image_spaces =
1942         Runtime::Current()->GetHeap()->GetBootImageSpaces();
1943     DCHECK(!image_spaces.empty());
1944     const OatFile* oat_file = image_spaces[0]->GetOatFile();
1945     CHECK(oat_file != nullptr);
1946     const OatHeader& header = oat_file->GetOatHeader();
1947     switch (type) {
1948       // TODO: We could maybe clean this up if we stored them in an array in the oat header.
1949       case kOatAddressQuickGenericJNITrampoline:
1950         return static_cast<const uint8_t*>(header.GetQuickGenericJniTrampoline());
1951       case kOatAddressInterpreterToInterpreterBridge:
1952         return static_cast<const uint8_t*>(header.GetInterpreterToInterpreterBridge());
1953       case kOatAddressInterpreterToCompiledCodeBridge:
1954         return static_cast<const uint8_t*>(header.GetInterpreterToCompiledCodeBridge());
1955       case kOatAddressJNIDlsymLookup:
1956         return static_cast<const uint8_t*>(header.GetJniDlsymLookup());
1957       case kOatAddressQuickIMTConflictTrampoline:
1958         return static_cast<const uint8_t*>(header.GetQuickImtConflictTrampoline());
1959       case kOatAddressQuickResolutionTrampoline:
1960         return static_cast<const uint8_t*>(header.GetQuickResolutionTrampoline());
1961       case kOatAddressQuickToInterpreterBridge:
1962         return static_cast<const uint8_t*>(header.GetQuickToInterpreterBridge());
1963       default:
1964         UNREACHABLE();
1965     }
1966   }
1967   const ImageInfo& primary_image_info = GetImageInfo(0);
1968   return GetOatAddressForOffset(primary_image_info.oat_address_offsets_[type], primary_image_info);
1969 }
1970
1971 const uint8_t* ImageWriter::GetQuickCode(ArtMethod* method,
1972                                          const ImageInfo& image_info,
1973                                          bool* quick_is_interpreted) {
1974   DCHECK(!method->IsResolutionMethod()) << PrettyMethod(method);
1975   DCHECK(!method->IsImtConflictMethod()) << PrettyMethod(method);
1976   DCHECK(!method->IsImtUnimplementedMethod()) << PrettyMethod(method);
1977   DCHECK(method->IsInvokable()) << PrettyMethod(method);
1978   DCHECK(!IsInBootImage(method)) << PrettyMethod(method);
1979
1980   // Use original code if it exists. Otherwise, set the code pointer to the resolution
1981   // trampoline.
1982
1983   // Quick entrypoint:
1984   const void* quick_oat_entry_point =
1985       method->GetEntryPointFromQuickCompiledCodePtrSize(target_ptr_size_);
1986   const uint8_t* quick_code;
1987
1988   if (UNLIKELY(IsInBootImage(method->GetDeclaringClass()))) {
1989     DCHECK(method->IsCopied());
1990     // If the code is not in the oat file corresponding to this image (e.g. default methods)
1991     quick_code = reinterpret_cast<const uint8_t*>(quick_oat_entry_point);
1992   } else {
1993     uint32_t quick_oat_code_offset = PointerToLowMemUInt32(quick_oat_entry_point);
1994     quick_code = GetOatAddressForOffset(quick_oat_code_offset, image_info);
1995   }
1996
1997   *quick_is_interpreted = false;
1998   if (quick_code != nullptr && (!method->IsStatic() || method->IsConstructor() ||
1999       method->GetDeclaringClass()->IsInitialized())) {
2000     // We have code for a non-static or initialized method, just use the code.
2001   } else if (quick_code == nullptr && method->IsNative() &&
2002       (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) {
2003     // Non-static or initialized native method missing compiled code, use generic JNI version.
2004     quick_code = GetOatAddress(kOatAddressQuickGenericJNITrampoline);
2005   } else if (quick_code == nullptr && !method->IsNative()) {
2006     // We don't have code at all for a non-native method, use the interpreter.
2007     quick_code = GetOatAddress(kOatAddressQuickToInterpreterBridge);
2008     *quick_is_interpreted = true;
2009   } else {
2010     CHECK(!method->GetDeclaringClass()->IsInitialized());
2011     // We have code for a static method, but need to go through the resolution stub for class
2012     // initialization.
2013     quick_code = GetOatAddress(kOatAddressQuickResolutionTrampoline);
2014   }
2015   if (!IsInBootOatFile(quick_code)) {
2016     // DCHECK_GE(quick_code, oat_data_begin_);
2017   }
2018   return quick_code;
2019 }
2020
2021 void ImageWriter::CopyAndFixupMethod(ArtMethod* orig,
2022                                      ArtMethod* copy,
2023                                      const ImageInfo& image_info) {
2024   memcpy(copy, orig, ArtMethod::Size(target_ptr_size_));
2025
2026   copy->SetDeclaringClass(GetImageAddress(orig->GetDeclaringClassUnchecked()));
2027
2028   ArtMethod** orig_resolved_methods = orig->GetDexCacheResolvedMethods(target_ptr_size_);
2029   copy->SetDexCacheResolvedMethods(NativeLocationInImage(orig_resolved_methods), target_ptr_size_);
2030   GcRoot<mirror::Class>* orig_resolved_types = orig->GetDexCacheResolvedTypes(target_ptr_size_);
2031   copy->SetDexCacheResolvedTypes(NativeLocationInImage(orig_resolved_types), target_ptr_size_);
2032
2033   // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
2034   // oat_begin_
2035
2036   // The resolution method has a special trampoline to call.
2037   Runtime* runtime = Runtime::Current();
2038   if (UNLIKELY(orig == runtime->GetResolutionMethod())) {
2039     copy->SetEntryPointFromQuickCompiledCodePtrSize(
2040         GetOatAddress(kOatAddressQuickResolutionTrampoline), target_ptr_size_);
2041   } else if (UNLIKELY(orig == runtime->GetImtConflictMethod() ||
2042                       orig == runtime->GetImtUnimplementedMethod())) {
2043     copy->SetEntryPointFromQuickCompiledCodePtrSize(
2044         GetOatAddress(kOatAddressQuickIMTConflictTrampoline), target_ptr_size_);
2045   } else if (UNLIKELY(orig->IsRuntimeMethod())) {
2046     bool found_one = false;
2047     for (size_t i = 0; i < static_cast<size_t>(Runtime::kLastCalleeSaveType); ++i) {
2048       auto idx = static_cast<Runtime::CalleeSaveType>(i);
2049       if (runtime->HasCalleeSaveMethod(idx) && runtime->GetCalleeSaveMethod(idx) == orig) {
2050         found_one = true;
2051         break;
2052       }
2053     }
2054     CHECK(found_one) << "Expected to find callee save method but got " << PrettyMethod(orig);
2055     CHECK(copy->IsRuntimeMethod());
2056   } else {
2057     // We assume all methods have code. If they don't currently then we set them to the use the
2058     // resolution trampoline. Abstract methods never have code and so we need to make sure their
2059     // use results in an AbstractMethodError. We use the interpreter to achieve this.
2060     if (UNLIKELY(!orig->IsInvokable())) {
2061       copy->SetEntryPointFromQuickCompiledCodePtrSize(
2062           GetOatAddress(kOatAddressQuickToInterpreterBridge), target_ptr_size_);
2063     } else {
2064       bool quick_is_interpreted;
2065       const uint8_t* quick_code = GetQuickCode(orig, image_info, &quick_is_interpreted);
2066       copy->SetEntryPointFromQuickCompiledCodePtrSize(quick_code, target_ptr_size_);
2067
2068       // JNI entrypoint:
2069       if (orig->IsNative()) {
2070         // The native method's pointer is set to a stub to lookup via dlsym.
2071         // Note this is not the code_ pointer, that is handled above.
2072         copy->SetEntryPointFromJniPtrSize(
2073             GetOatAddress(kOatAddressJNIDlsymLookup), target_ptr_size_);
2074       }
2075     }
2076   }
2077 }
2078
2079 size_t ImageWriter::GetBinSizeSum(ImageWriter::ImageInfo& image_info, ImageWriter::Bin up_to) const {
2080   DCHECK_LE(up_to, kBinSize);
2081   return std::accumulate(&image_info.bin_slot_sizes_[0],
2082                          &image_info.bin_slot_sizes_[up_to],
2083                          /*init*/0);
2084 }
2085
2086 ImageWriter::BinSlot::BinSlot(uint32_t lockword) : lockword_(lockword) {
2087   // These values may need to get updated if more bins are added to the enum Bin
2088   static_assert(kBinBits == 3, "wrong number of bin bits");
2089   static_assert(kBinShift == 27, "wrong number of shift");
2090   static_assert(sizeof(BinSlot) == sizeof(LockWord), "BinSlot/LockWord must have equal sizes");
2091
2092   DCHECK_LT(GetBin(), kBinSize);
2093   DCHECK_ALIGNED(GetIndex(), kObjectAlignment);
2094 }
2095
2096 ImageWriter::BinSlot::BinSlot(Bin bin, uint32_t index)
2097     : BinSlot(index | (static_cast<uint32_t>(bin) << kBinShift)) {
2098   DCHECK_EQ(index, GetIndex());
2099 }
2100
2101 ImageWriter::Bin ImageWriter::BinSlot::GetBin() const {
2102   return static_cast<Bin>((lockword_ & kBinMask) >> kBinShift);
2103 }
2104
2105 uint32_t ImageWriter::BinSlot::GetIndex() const {
2106   return lockword_ & ~kBinMask;
2107 }
2108
2109 ImageWriter::Bin ImageWriter::BinTypeForNativeRelocationType(NativeObjectRelocationType type) {
2110   switch (type) {
2111     case kNativeObjectRelocationTypeArtField:
2112     case kNativeObjectRelocationTypeArtFieldArray:
2113       return kBinArtField;
2114     case kNativeObjectRelocationTypeArtMethodClean:
2115     case kNativeObjectRelocationTypeArtMethodArrayClean:
2116       return kBinArtMethodClean;
2117     case kNativeObjectRelocationTypeArtMethodDirty:
2118     case kNativeObjectRelocationTypeArtMethodArrayDirty:
2119       return kBinArtMethodDirty;
2120     case kNativeObjectRelocationTypeDexCacheArray:
2121       return kBinDexCacheArray;
2122   }
2123   UNREACHABLE();
2124 }
2125
2126 size_t ImageWriter::GetOatIndex(mirror::Object* obj) const {
2127   if (compile_app_image_) {
2128     return GetDefaultOatIndex();
2129   } else {
2130     mirror::DexCache* dex_cache =
2131         obj->IsDexCache() ? obj->AsDexCache()
2132                           : obj->IsClass() ? obj->AsClass()->GetDexCache()
2133                                            : obj->GetClass()->GetDexCache();
2134     return GetOatIndexForDexCache(dex_cache);
2135   }
2136 }
2137
2138 size_t ImageWriter::GetOatIndexForDexFile(const DexFile* dex_file) const {
2139   if (compile_app_image_) {
2140     return GetDefaultOatIndex();
2141   } else {
2142     auto it = dex_file_oat_index_map_.find(dex_file);
2143     DCHECK(it != dex_file_oat_index_map_.end()) << dex_file->GetLocation();
2144     return it->second;
2145   }
2146 }
2147
2148 size_t ImageWriter::GetOatIndexForDexCache(mirror::DexCache* dex_cache) const {
2149   if (dex_cache == nullptr) {
2150     return GetDefaultOatIndex();
2151   } else {
2152     return GetOatIndexForDexFile(dex_cache->GetDexFile());
2153   }
2154 }
2155
2156 void ImageWriter::UpdateOatFileLayout(size_t oat_index,
2157                                       size_t oat_loaded_size,
2158                                       size_t oat_data_offset,
2159                                       size_t oat_data_size) {
2160   const uint8_t* images_end = image_infos_.back().image_begin_ + image_infos_.back().image_size_;
2161   for (const ImageInfo& info : image_infos_) {
2162     DCHECK_LE(info.image_begin_ + info.image_size_, images_end);
2163   }
2164   DCHECK(images_end != nullptr);  // Image space must be ready.
2165
2166   ImageInfo& cur_image_info = GetImageInfo(oat_index);
2167   cur_image_info.oat_file_begin_ = images_end + cur_image_info.oat_offset_;
2168   cur_image_info.oat_loaded_size_ = oat_loaded_size;
2169   cur_image_info.oat_data_begin_ = cur_image_info.oat_file_begin_ + oat_data_offset;
2170   cur_image_info.oat_size_ = oat_data_size;
2171
2172   if (compile_app_image_) {
2173     CHECK_EQ(oat_filenames_.size(), 1u) << "App image should have no next image.";
2174     return;
2175   }
2176
2177   // Update the oat_offset of the next image info.
2178   if (oat_index + 1u != oat_filenames_.size()) {
2179     // There is a following one.
2180     ImageInfo& next_image_info = GetImageInfo(oat_index + 1u);
2181     next_image_info.oat_offset_ = cur_image_info.oat_offset_ + oat_loaded_size;
2182   }
2183 }
2184
2185 void ImageWriter::UpdateOatFileHeader(size_t oat_index, const OatHeader& oat_header) {
2186   ImageInfo& cur_image_info = GetImageInfo(oat_index);
2187   cur_image_info.oat_checksum_ = oat_header.GetChecksum();
2188
2189   if (oat_index == GetDefaultOatIndex()) {
2190     // Primary oat file, read the trampolines.
2191     cur_image_info.oat_address_offsets_[kOatAddressInterpreterToInterpreterBridge] =
2192         oat_header.GetInterpreterToInterpreterBridgeOffset();
2193     cur_image_info.oat_address_offsets_[kOatAddressInterpreterToCompiledCodeBridge] =
2194         oat_header.GetInterpreterToCompiledCodeBridgeOffset();
2195     cur_image_info.oat_address_offsets_[kOatAddressJNIDlsymLookup] =
2196         oat_header.GetJniDlsymLookupOffset();
2197     cur_image_info.oat_address_offsets_[kOatAddressQuickGenericJNITrampoline] =
2198         oat_header.GetQuickGenericJniTrampolineOffset();
2199     cur_image_info.oat_address_offsets_[kOatAddressQuickIMTConflictTrampoline] =
2200         oat_header.GetQuickImtConflictTrampolineOffset();
2201     cur_image_info.oat_address_offsets_[kOatAddressQuickResolutionTrampoline] =
2202         oat_header.GetQuickResolutionTrampolineOffset();
2203     cur_image_info.oat_address_offsets_[kOatAddressQuickToInterpreterBridge] =
2204         oat_header.GetQuickToInterpreterBridgeOffset();
2205   }
2206 }
2207
2208 ImageWriter::ImageWriter(
2209     const CompilerDriver& compiler_driver,
2210     uintptr_t image_begin,
2211     bool compile_pic,
2212     bool compile_app_image,
2213     ImageHeader::StorageMode image_storage_mode,
2214     const std::vector<const char*>& oat_filenames,
2215     const std::unordered_map<const DexFile*, size_t>& dex_file_oat_index_map)
2216     : compiler_driver_(compiler_driver),
2217       global_image_begin_(reinterpret_cast<uint8_t*>(image_begin)),
2218       image_objects_offset_begin_(0),
2219       compile_pic_(compile_pic),
2220       compile_app_image_(compile_app_image),
2221       target_ptr_size_(InstructionSetPointerSize(compiler_driver_.GetInstructionSet())),
2222       image_infos_(oat_filenames.size()),
2223       image_method_array_(ImageHeader::kImageMethodsCount),
2224       dirty_methods_(0u),
2225       clean_methods_(0u),
2226       image_storage_mode_(image_storage_mode),
2227       oat_filenames_(oat_filenames),
2228       dex_file_oat_index_map_(dex_file_oat_index_map) {
2229   CHECK_NE(image_begin, 0U);
2230   std::fill_n(image_methods_, arraysize(image_methods_), nullptr);
2231   CHECK_EQ(compile_app_image, !Runtime::Current()->GetHeap()->GetBootImageSpaces().empty())
2232       << "Compiling a boot image should occur iff there are no boot image spaces loaded";
2233 }
2234
2235 ImageWriter::ImageInfo::ImageInfo()
2236     : intern_table_(new InternTable),
2237       class_table_(new ClassTable) {}
2238
2239 }  // namespace art