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::kStorageModeLZ4HC:  // Fall-through.
 233       case ImageHeader::kStorageModeLZ4: {
 234         const size_t compressed_max_size = LZ4_compressBound(image_data_size);
 235         compressed_data.reset(new char[compressed_max_size]);
 236         data_size = LZ4_compress(
 237             reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader),
 238             &compressed_data[0],
 239             image_data_size);
 240
 241         break;
 242       }
 243       /*
 244        * Disabled due to image_test64 flakyness. Both use same decompression. b/27560444
 245       case ImageHeader::kStorageModeLZ4HC: {
 246         // Bound is same as non HC.
 247         const size_t compressed_max_size = LZ4_compressBound(image_data_size);
 248         compressed_data.reset(new char[compressed_max_size]);
 249         data_size = LZ4_compressHC(
 250             reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader),
 251             &compressed_data[0],
 252             image_data_size);
 253         break;
 254       }
 255       */
 256       case ImageHeader::kStorageModeUncompressed: {
 257         data_size = image_data_size;
 258         image_data_to_write = image_data;
 259         break;
 260       }
 261       default: {
 262         LOG(FATAL) << "Unsupported";
 263         UNREACHABLE();
 264       }
 265     }
 266
 267     if (compressed_data != nullptr) {
 268       image_data_to_write = &compressed_data[0];
 269       VLOG(compiler) << "Compressed from " << image_data_size << " to " << data_size << " in "
 270                      << PrettyDuration(NanoTime() - compress_start_time);
 271       if (kIsDebugBuild) {
 272         std::unique_ptr<uint8_t[]> temp(new uint8_t[image_data_size]);
 273         const size_t decompressed_size = LZ4_decompress_safe(
 274             reinterpret_cast<char*>(&compressed_data[0]),
 275             reinterpret_cast<char*>(&temp[0]),
 276             data_size,
 277             image_data_size);
 278         CHECK_EQ(decompressed_size, image_data_size);
 279         CHECK_EQ(memcmp(image_data, &temp[0], image_data_size), 0) << image_storage_mode_;
 280       }
 281     }
 282
 283     // Write out the image + fields + methods.
 284     const bool is_compressed = compressed_data != nullptr;
 285     if (!image_file->PwriteFully(image_data_to_write, data_size, sizeof(ImageHeader))) {
 286       PLOG(ERROR) << "Failed to write image file data " << image_filename;
 287       image_file->Erase();
 288       return false;
 289     }
 290
 291     // Write out the image bitmap at the page aligned start of the image end, also uncompressed for
 292     // convenience.
 293     const ImageSection& bitmap_section = image_header->GetImageSection(
 294         ImageHeader::kSectionImageBitmap);
 295     // Align up since data size may be unaligned if the image is compressed.
 296     size_t bitmap_position_in_file = RoundUp(sizeof(ImageHeader) + data_size, kPageSize);
 297     if (!is_compressed) {
 298       CHECK_EQ(bitmap_position_in_file, bitmap_section.Offset());
 299     }
 300     if (!image_file->PwriteFully(reinterpret_cast<char*>(image_info.image_bitmap_->Begin()),
 301                                  bitmap_section.Size(),
 302                                  bitmap_position_in_file)) {
 303       PLOG(ERROR) << "Failed to write image file " << image_filename;
 304       image_file->Erase();
 305       return false;
 306     }
 307
 308     int err = image_file->Flush();
 309     if (err < 0) {
 310       PLOG(ERROR) << "Failed to flush image file " << image_filename << " with result " << err;
 311       image_file->Erase();
 312       return false;
 313     }
 314
 315     // Write header last in case the compiler gets killed in the middle of image writing.
 316     // We do not want to have a corrupted image with a valid header.
 317     // The header is uncompressed since it contains whether the image is compressed or not.
 318     image_header->data_size_ = data_size;
 319     if (!image_file->PwriteFully(reinterpret_cast<char*>(image_info.image_->Begin()),
 320                                  sizeof(ImageHeader),
 321                                  0)) {
 322       PLOG(ERROR) << "Failed to write image file header " << image_filename;
 323       image_file->Erase();
 324       return false;
 325     }
 326
 327     CHECK_EQ(bitmap_position_in_file + bitmap_section.Size(),
 328              static_cast<size_t>(image_file->GetLength()));
 329     if (image_file->FlushCloseOrErase() != 0) {
 330       PLOG(ERROR) << "Failed to flush and close image file " << image_filename;
 331       return false;
 332     }
 333   }
 334   return true;
 335 }
 336
 337 void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
 338   DCHECK(object != nullptr);
 339   DCHECK_NE(offset, 0U);
 340
 341   // The object is already deflated from when we set the bin slot. Just overwrite the lock word.
 342   object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
 343   DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u);
 344   DCHECK(IsImageOffsetAssigned(object));
 345 }
 346
 347 void ImageWriter::UpdateImageOffset(mirror::Object* obj, uintptr_t offset) {
 348   DCHECK(IsImageOffsetAssigned(obj)) << obj << " " << offset;
 349   obj->SetLockWord(LockWord::FromForwardingAddress(offset), false);
 350   DCHECK_EQ(obj->GetLockWord(false).ReadBarrierState(), 0u);
 351 }
 352
 353 void ImageWriter::AssignImageOffset(mirror::Object* object, ImageWriter::BinSlot bin_slot) {
 354   DCHECK(object != nullptr);
 355   DCHECK_NE(image_objects_offset_begin_, 0u);
 356
 357   size_t oat_index = GetOatIndex(object);
 358   ImageInfo& image_info = GetImageInfo(oat_index);
 359   size_t bin_slot_offset = image_info.bin_slot_offsets_[bin_slot.GetBin()];
 360   size_t new_offset = bin_slot_offset + bin_slot.GetIndex();
 361   DCHECK_ALIGNED(new_offset, kObjectAlignment);
 362
 363   SetImageOffset(object, new_offset);
 364   DCHECK_LT(new_offset, image_info.image_end_);
 365 }
 366
 367 bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
 368   // Will also return true if the bin slot was assigned since we are reusing the lock word.
 369   DCHECK(object != nullptr);
 370   return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress;
 371 }
 372
 373 size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
 374   DCHECK(object != nullptr);
 375   DCHECK(IsImageOffsetAssigned(object));
 376   LockWord lock_word = object->GetLockWord(false);
 377   size_t offset = lock_word.ForwardingAddress();
 378   size_t oat_index = GetOatIndex(object);
 379   const ImageInfo& image_info = GetImageInfo(oat_index);
 380   DCHECK_LT(offset, image_info.image_end_);
 381   return offset;
 382 }
 383
 384 void ImageWriter::SetImageBinSlot(mirror::Object* object, BinSlot bin_slot) {
 385   DCHECK(object != nullptr);
 386   DCHECK(!IsImageOffsetAssigned(object));
 387   DCHECK(!IsImageBinSlotAssigned(object));
 388
 389   // Before we stomp over the lock word, save the hash code for later.
 390   Monitor::Deflate(Thread::Current(), object);;
 391   LockWord lw(object->GetLockWord(false));
 392   switch (lw.GetState()) {
 393     case LockWord::kFatLocked: {
 394       LOG(FATAL) << "Fat locked object " << object << " found during object copy";
 395       break;
 396     }
 397     case LockWord::kThinLocked: {
 398       LOG(FATAL) << "Thin locked object " << object << " found during object copy";
 399       break;
 400     }
 401     case LockWord::kUnlocked:
 402       // No hash, don't need to save it.
 403       break;
 404     case LockWord::kHashCode:
 405       DCHECK(saved_hashcode_map_.find(object) == saved_hashcode_map_.end());
 406       saved_hashcode_map_.emplace(object, lw.GetHashCode());
 407       break;
 408     default:
 409       LOG(FATAL) << "Unreachable.";
 410       UNREACHABLE();
 411   }
 412   object->SetLockWord(LockWord::FromForwardingAddress(bin_slot.Uint32Value()), false);
 413   DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u);
 414   DCHECK(IsImageBinSlotAssigned(object));
 415 }
 416
 417 void ImageWriter::PrepareDexCacheArraySlots() {
 418   // Prepare dex cache array starts based on the ordering specified in the CompilerDriver.
 419   // Set the slot size early to avoid DCHECK() failures in IsImageBinSlotAssigned()
 420   // when AssignImageBinSlot() assigns their indexes out or order.
 421   for (const DexFile* dex_file : compiler_driver_.GetDexFilesForOatFile()) {
 422     auto it = dex_file_oat_index_map_.find(dex_file);
 423     DCHECK(it != dex_file_oat_index_map_.end()) << dex_file->GetLocation();
 424     ImageInfo& image_info = GetImageInfo(it->second);
 425     image_info.dex_cache_array_starts_.Put(dex_file, image_info.bin_slot_sizes_[kBinDexCacheArray]);
 426     DexCacheArraysLayout layout(target_ptr_size_, dex_file);
 427     image_info.bin_slot_sizes_[kBinDexCacheArray] += layout.Size();
 428   }
 429
 430   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
 431   Thread* const self = Thread::Current();
 432   ReaderMutexLock mu(self, *class_linker->DexLock());
 433   for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
 434     mirror::DexCache* dex_cache =
 435         down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
 436     if (dex_cache == nullptr || IsInBootImage(dex_cache)) {
 437       continue;
 438     }
 439     const DexFile* dex_file = dex_cache->GetDexFile();
 440     DexCacheArraysLayout layout(target_ptr_size_, dex_file);
 441     DCHECK(layout.Valid());
 442     size_t oat_index = GetOatIndexForDexCache(dex_cache);
 443     ImageInfo& image_info = GetImageInfo(oat_index);
 444     uint32_t start = image_info.dex_cache_array_starts_.Get(dex_file);
 445     DCHECK_EQ(dex_file->NumTypeIds() != 0u, dex_cache->GetResolvedTypes() != nullptr);
 446     AddDexCacheArrayRelocation(dex_cache->GetResolvedTypes(),
 447                                start + layout.TypesOffset(),
 448                                dex_cache);
 449     DCHECK_EQ(dex_file->NumMethodIds() != 0u, dex_cache->GetResolvedMethods() != nullptr);
 450     AddDexCacheArrayRelocation(dex_cache->GetResolvedMethods(),
 451                                start + layout.MethodsOffset(),
 452                                dex_cache);
 453     DCHECK_EQ(dex_file->NumFieldIds() != 0u, dex_cache->GetResolvedFields() != nullptr);
 454     AddDexCacheArrayRelocation(dex_cache->GetResolvedFields(),
 455                                start + layout.FieldsOffset(),
 456                                dex_cache);
 457     DCHECK_EQ(dex_file->NumStringIds() != 0u, dex_cache->GetStrings() != nullptr);
 458     AddDexCacheArrayRelocation(dex_cache->GetStrings(), start + layout.StringsOffset(), dex_cache);
 459   }
 460 }
 461
 462 void ImageWriter::AddDexCacheArrayRelocation(void* array, size_t offset, DexCache* dex_cache) {
 463   if (array != nullptr) {
 464     DCHECK(!IsInBootImage(array));
 465     size_t oat_index = GetOatIndexForDexCache(dex_cache);
 466     native_object_relocations_.emplace(array,
 467         NativeObjectRelocation { oat_index, offset, kNativeObjectRelocationTypeDexCacheArray });
 468   }
 469 }
 470
 471 void ImageWriter::AddMethodPointerArray(mirror::PointerArray* arr) {
 472   DCHECK(arr != nullptr);
 473   if (kIsDebugBuild) {
 474     for (size_t i = 0, len = arr->GetLength(); i < len; i++) {
 475       ArtMethod* method = arr->GetElementPtrSize<ArtMethod*>(i, target_ptr_size_);
 476       if (method != nullptr && !method->IsRuntimeMethod()) {
 477         mirror::Class* klass = method->GetDeclaringClass();
 478         CHECK(klass == nullptr || KeepClass(klass))
 479             << PrettyClass(klass) << " should be a kept class";
 480       }
 481     }
 482   }
 483   // kBinArtMethodClean picked arbitrarily, just required to differentiate between ArtFields and
 484   // ArtMethods.
 485   pointer_arrays_.emplace(arr, kBinArtMethodClean);
 486 }
 487
 488 void ImageWriter::AssignImageBinSlot(mirror::Object* object) {
 489   DCHECK(object != nullptr);
 490   size_t object_size = object->SizeOf();
 491
 492   // The magic happens here. We segregate objects into different bins based
 493   // on how likely they are to get dirty at runtime.
 494   //
 495   // Likely-to-dirty objects get packed together into the same bin so that
 496   // at runtime their page dirtiness ratio (how many dirty objects a page has) is
 497   // maximized.
 498   //
 499   // This means more pages will stay either clean or shared dirty (with zygote) and
 500   // the app will use less of its own (private) memory.
 501   Bin bin = kBinRegular;
 502   size_t current_offset = 0u;
 503
 504   if (kBinObjects) {
 505     //
 506     // Changing the bin of an object is purely a memory-use tuning.
 507     // It has no change on runtime correctness.
 508     //
 509     // Memory analysis has determined that the following types of objects get dirtied
 510     // the most:
 511     //
 512     // * Dex cache arrays are stored in a special bin. The arrays for each dex cache have
 513     //   a fixed layout which helps improve generated code (using PC-relative addressing),
 514     //   so we pre-calculate their offsets separately in PrepareDexCacheArraySlots().
 515     //   Since these arrays are huge, most pages do not overlap other objects and it's not
 516     //   really important where they are for the clean/dirty separation. Due to their
 517     //   special PC-relative addressing, we arbitrarily keep them at the end.
 518     // * Class'es which are verified [their clinit runs only at runtime]
 519     //   - classes in general [because their static fields get overwritten]
 520     //   - initialized classes with all-final statics are unlikely to be ever dirty,
 521     //     so bin them separately
 522     // * Art Methods that are:
 523     //   - native [their native entry point is not looked up until runtime]
 524     //   - have declaring classes that aren't initialized
 525     //            [their interpreter/quick entry points are trampolines until the class
 526     //             becomes initialized]
 527     //
 528     // We also assume the following objects get dirtied either never or extremely rarely:
 529     //  * Strings (they are immutable)
 530     //  * Art methods that aren't native and have initialized declared classes
 531     //
 532     // We assume that "regular" bin objects are highly unlikely to become dirtied,
 533     // so packing them together will not result in a noticeably tighter dirty-to-clean ratio.
 534     //
 535     if (object->IsClass()) {
 536       bin = kBinClassVerified;
 537       mirror::Class* klass = object->AsClass();
 538
 539       // Add non-embedded vtable to the pointer array table if there is one.
 540       auto* vtable = klass->GetVTable();
 541       if (vtable != nullptr) {
 542         AddMethodPointerArray(vtable);
 543       }
 544       auto* iftable = klass->GetIfTable();
 545       if (iftable != nullptr) {
 546         for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) {
 547           if (iftable->GetMethodArrayCount(i) > 0) {
 548             AddMethodPointerArray(iftable->GetMethodArray(i));
 549           }
 550         }
 551       }
 552
 553       if (klass->GetStatus() == Class::kStatusInitialized) {
 554         bin = kBinClassInitialized;
 555
 556         // If the class's static fields are all final, put it into a separate bin
 557         // since it's very likely it will stay clean.
 558         uint32_t num_static_fields = klass->NumStaticFields();
 559         if (num_static_fields == 0) {
 560           bin = kBinClassInitializedFinalStatics;
 561         } else {
 562           // Maybe all the statics are final?
 563           bool all_final = true;
 564           for (uint32_t i = 0; i < num_static_fields; ++i) {
 565             ArtField* field = klass->GetStaticField(i);
 566             if (!field->IsFinal()) {
 567               all_final = false;
 568               break;
 569             }
 570           }
 571
 572           if (all_final) {
 573             bin = kBinClassInitializedFinalStatics;
 574           }
 575         }
 576       }
 577     } else if (object->GetClass<kVerifyNone>()->IsStringClass()) {
 578       bin = kBinString;  // Strings are almost always immutable (except for object header).
 579     }  // else bin = kBinRegular
 580   }
 581
 582   size_t oat_index = GetOatIndex(object);
 583   ImageInfo& image_info = GetImageInfo(oat_index);
 584
 585   size_t offset_delta = RoundUp(object_size, kObjectAlignment);  // 64-bit alignment
 586   current_offset = image_info.bin_slot_sizes_[bin];  // How many bytes the current bin is at (aligned).
 587   // Move the current bin size up to accommodate the object we just assigned a bin slot.
 588   image_info.bin_slot_sizes_[bin] += offset_delta;
 589
 590   BinSlot new_bin_slot(bin, current_offset);
 591   SetImageBinSlot(object, new_bin_slot);
 592
 593   ++image_info.bin_slot_count_[bin];
 594
 595   // Grow the image closer to the end by the object we just assigned.
 596   image_info.image_end_ += offset_delta;
 597 }
 598
 599 bool ImageWriter::WillMethodBeDirty(ArtMethod* m) const {
 600   if (m->IsNative()) {
 601     return true;
 602   }
 603   mirror::Class* declaring_class = m->GetDeclaringClass();
 604   // Initialized is highly unlikely to dirty since there's no entry points to mutate.
 605   return declaring_class == nullptr || declaring_class->GetStatus() != Class::kStatusInitialized;
 606 }
 607
 608 bool ImageWriter::IsImageBinSlotAssigned(mirror::Object* object) const {
 609   DCHECK(object != nullptr);
 610
 611   // We always stash the bin slot into a lockword, in the 'forwarding address' state.
 612   // If it's in some other state, then we haven't yet assigned an image bin slot.
 613   if (object->GetLockWord(false).GetState() != LockWord::kForwardingAddress) {
 614     return false;
 615   } else if (kIsDebugBuild) {
 616     LockWord lock_word = object->GetLockWord(false);
 617     size_t offset = lock_word.ForwardingAddress();
 618     BinSlot bin_slot(offset);
 619     size_t oat_index = GetOatIndex(object);
 620     const ImageInfo& image_info = GetImageInfo(oat_index);
 621     DCHECK_LT(bin_slot.GetIndex(), image_info.bin_slot_sizes_[bin_slot.GetBin()])
 622         << "bin slot offset should not exceed the size of that bin";
 623   }
 624   return true;
 625 }
 626
 627 ImageWriter::BinSlot ImageWriter::GetImageBinSlot(mirror::Object* object) const {
 628   DCHECK(object != nullptr);
 629   DCHECK(IsImageBinSlotAssigned(object));
 630
 631   LockWord lock_word = object->GetLockWord(false);
 632   size_t offset = lock_word.ForwardingAddress();  // TODO: ForwardingAddress should be uint32_t
 633   DCHECK_LE(offset, std::numeric_limits<uint32_t>::max());
 634
 635   BinSlot bin_slot(static_cast<uint32_t>(offset));
 636   size_t oat_index = GetOatIndex(object);
 637   const ImageInfo& image_info = GetImageInfo(oat_index);
 638   DCHECK_LT(bin_slot.GetIndex(), image_info.bin_slot_sizes_[bin_slot.GetBin()]);
 639
 640   return bin_slot;
 641 }
 642
 643 bool ImageWriter::AllocMemory() {
 644   for (ImageInfo& image_info : image_infos_) {
 645     ImageSection unused_sections[ImageHeader::kSectionCount];
 646     const size_t length = RoundUp(
 647         image_info.CreateImageSections(target_ptr_size_, unused_sections),
 648         kPageSize);
 649
 650     std::string error_msg;
 651     image_info.image_.reset(MemMap::MapAnonymous("image writer image",
 652                                                  nullptr,
 653                                                  length,
 654                                                  PROT_READ | PROT_WRITE,
 655                                                  false,
 656                                                  false,
 657                                                  &error_msg));
 658     if (UNLIKELY(image_info.image_.get() == nullptr)) {
 659       LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
 660       return false;
 661     }
 662
 663     // Create the image bitmap, only needs to cover mirror object section which is up to image_end_.
 664     CHECK_LE(image_info.image_end_, length);
 665     image_info.image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create(
 666         "image bitmap", image_info.image_->Begin(), RoundUp(image_info.image_end_, kPageSize)));
 667     if (image_info.image_bitmap_.get() == nullptr) {
 668       LOG(ERROR) << "Failed to allocate memory for image bitmap";
 669       return false;
 670     }
 671   }
 672   return true;
 673 }
 674
 675 class ComputeLazyFieldsForClassesVisitor : public ClassVisitor {
 676  public:
 677   bool operator()(Class* c) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
 678     StackHandleScope<1> hs(Thread::Current());
 679     mirror::Class::ComputeName(hs.NewHandle(c));
 680     return true;
 681   }
 682 };
 683
 684 void ImageWriter::ComputeLazyFieldsForImageClasses() {
 685   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
 686   ComputeLazyFieldsForClassesVisitor visitor;
 687   class_linker->VisitClassesWithoutClassesLock(&visitor);
 688 }
 689
 690 static bool IsBootClassLoaderClass(mirror::Class* klass) SHARED_REQUIRES(Locks::mutator_lock_) {
 691   return klass->GetClassLoader() == nullptr;
 692 }
 693
 694 bool ImageWriter::IsBootClassLoaderNonImageClass(mirror::Class* klass) {
 695   return IsBootClassLoaderClass(klass) && !IsInBootImage(klass);
 696 }
 697
 698 bool ImageWriter::PruneAppImageClass(mirror::Class* klass) {
 699   bool early_exit = false;
 700   std::unordered_set<mirror::Class*> visited;
 701   return PruneAppImageClassInternal(klass, &early_exit, &visited);
 702 }
 703
 704 bool ImageWriter::PruneAppImageClassInternal(
 705     mirror::Class* klass,
 706     bool* early_exit,
 707     std::unordered_set<mirror::Class*>* visited) {
 708   DCHECK(early_exit != nullptr);
 709   DCHECK(visited != nullptr);
 710   DCHECK(compile_app_image_);
 711   if (klass == nullptr || IsInBootImage(klass)) {
 712     return false;
 713   }
 714   auto found = prune_class_memo_.find(klass);
 715   if (found != prune_class_memo_.end()) {
 716     // Already computed, return the found value.
 717     return found->second;
 718   }
 719   // Circular dependencies, return false but do not store the result in the memoization table.
 720   if (visited->find(klass) != visited->end()) {
 721     *early_exit = true;
 722     return false;
 723   }
 724   visited->emplace(klass);
 725   bool result = IsBootClassLoaderClass(klass);
 726   std::string temp;
 727   // Prune if not an image class, this handles any broken sets of image classes such as having a
 728   // class in the set but not it's superclass.
 729   result = result || !compiler_driver_.IsImageClass(klass->GetDescriptor(&temp));
 730   bool my_early_exit = false;  // Only for ourselves, ignore caller.
 731   // Remove classes that failed to verify since we don't want to have java.lang.VerifyError in the
 732   // app image.
 733   if (klass->GetStatus() == mirror::Class::kStatusError) {
 734     result = true;
 735   } else {
 736     CHECK(klass->GetVerifyError() == nullptr) << PrettyClass(klass);
 737   }
 738   if (!result) {
 739     // Check interfaces since these wont be visited through VisitReferences.)
 740     mirror::IfTable* if_table = klass->GetIfTable();
 741     for (size_t i = 0, num_interfaces = klass->GetIfTableCount(); i < num_interfaces; ++i) {
 742       result = result || PruneAppImageClassInternal(if_table->GetInterface(i),
 743                                                     &my_early_exit,
 744                                                     visited);
 745     }
 746   }
 747   if (klass->IsObjectArrayClass()) {
 748     result = result || PruneAppImageClassInternal(klass->GetComponentType(),
 749                                                   &my_early_exit,
 750                                                   visited);
 751   }
 752   // Check static fields and their classes.
 753   size_t num_static_fields = klass->NumReferenceStaticFields();
 754   if (num_static_fields != 0 && klass->IsResolved()) {
 755     // Presumably GC can happen when we are cross compiling, it should not cause performance
 756     // problems to do pointer size logic.
 757     MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset(
 758         Runtime::Current()->GetClassLinker()->GetImagePointerSize());
 759     for (size_t i = 0u; i < num_static_fields; ++i) {
 760       mirror::Object* ref = klass->GetFieldObject<mirror::Object>(field_offset);
 761       if (ref != nullptr) {
 762         if (ref->IsClass()) {
 763           result = result || PruneAppImageClassInternal(ref->AsClass(),
 764                                                         &my_early_exit,
 765                                                         visited);
 766         } else {
 767           result = result || PruneAppImageClassInternal(ref->GetClass(),
 768                                                         &my_early_exit,
 769                                                         visited);
 770         }
 771       }
 772       field_offset = MemberOffset(field_offset.Uint32Value() +
 773                                   sizeof(mirror::HeapReference<mirror::Object>));
 774     }
 775   }
 776   result = result || PruneAppImageClassInternal(klass->GetSuperClass(),
 777                                                 &my_early_exit,
 778                                                 visited);
 779   // Erase the element we stored earlier since we are exiting the function.
 780   auto it = visited->find(klass);
 781   DCHECK(it != visited->end());
 782   visited->erase(it);
 783   // Only store result if it is true or none of the calls early exited due to circular
 784   // dependencies. If visited is empty then we are the root caller, in this case the cycle was in
 785   // a child call and we can remember the result.
 786   if (result == true || !my_early_exit || visited->empty()) {
 787     prune_class_memo_[klass] = result;
 788   }
 789   *early_exit |= my_early_exit;
 790   return result;
 791 }
 792
 793 bool ImageWriter::KeepClass(Class* klass) {
 794   if (klass == nullptr) {
 795     return false;
 796   }
 797   if (compile_app_image_ && Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(klass)) {
 798     // Already in boot image, return true.
 799     return true;
 800   }
 801   std::string temp;
 802   if (!compiler_driver_.IsImageClass(klass->GetDescriptor(&temp))) {
 803     return false;
 804   }
 805   if (compile_app_image_) {
 806     // For app images, we need to prune boot loader classes that are not in the boot image since
 807     // these may have already been loaded when the app image is loaded.
 808     // Keep classes in the boot image space since we don't want to re-resolve these.
 809     return !PruneAppImageClass(klass);
 810   }
 811   return true;
 812 }
 813
 814 class NonImageClassesVisitor : public ClassVisitor {
 815  public:
 816   explicit NonImageClassesVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {}
 817
 818   bool operator()(Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
 819     if (!image_writer_->KeepClass(klass)) {
 820       classes_to_prune_.insert(klass);
 821     }
 822     return true;
 823   }
 824
 825   std::unordered_set<mirror::Class*> classes_to_prune_;
 826   ImageWriter* const image_writer_;
 827 };
 828
 829 void ImageWriter::PruneNonImageClasses() {
 830   Runtime* runtime = Runtime::Current();
 831   ClassLinker* class_linker = runtime->GetClassLinker();
 832   Thread* self = Thread::Current();
 833
 834   // Make a list of classes we would like to prune.
 835   NonImageClassesVisitor visitor(this);
 836   class_linker->VisitClasses(&visitor);
 837
 838   // Remove the undesired classes from the class roots.
 839   VLOG(compiler) << "Pruning " << visitor.classes_to_prune_.size() << " classes";
 840   for (mirror::Class* klass : visitor.classes_to_prune_) {
 841     std::string temp;
 842     const char* name = klass->GetDescriptor(&temp);
 843     VLOG(compiler) << "Pruning class " << name;
 844     if (!compile_app_image_) {
 845       DCHECK(IsBootClassLoaderClass(klass));
 846     }
 847     bool result = class_linker->RemoveClass(name, klass->GetClassLoader());
 848     DCHECK(result);
 849   }
 850
 851   // Clear references to removed classes from the DexCaches.
 852   ArtMethod* resolution_method = runtime->GetResolutionMethod();
 853
 854   ScopedAssertNoThreadSuspension sa(self, __FUNCTION__);
 855   ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);  // For ClassInClassTable
 856   ReaderMutexLock mu2(self, *class_linker->DexLock());
 857   for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
 858     if (self->IsJWeakCleared(data.weak_root)) {
 859       continue;
 860     }
 861     mirror::DexCache* dex_cache = self->DecodeJObject(data.weak_root)->AsDexCache();
 862     for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
 863       Class* klass = dex_cache->GetResolvedType(i);
 864       if (klass != nullptr && !KeepClass(klass)) {
 865         dex_cache->SetResolvedType(i, nullptr);
 866       }
 867     }
 868     ArtMethod** resolved_methods = dex_cache->GetResolvedMethods();
 869     for (size_t i = 0, num = dex_cache->NumResolvedMethods(); i != num; ++i) {
 870       ArtMethod* method =
 871           mirror::DexCache::GetElementPtrSize(resolved_methods, i, target_ptr_size_);
 872       DCHECK(method != nullptr) << "Expected resolution method instead of null method";
 873       mirror::Class* declaring_class = method->GetDeclaringClass();
 874       // Copied methods may be held live by a class which was not an image class but have a
 875       // declaring class which is an image class. Set it to the resolution method to be safe and
 876       // prevent dangling pointers.
 877       if (method->IsCopied() || !KeepClass(declaring_class)) {
 878         mirror::DexCache::SetElementPtrSize(resolved_methods,
 879                                             i,
 880                                             resolution_method,
 881                                             target_ptr_size_);
 882       } else {
 883         // Check that the class is still in the classes table.
 884         DCHECK(class_linker->ClassInClassTable(declaring_class)) << "Class "
 885             << PrettyClass(declaring_class) << " not in class linker table";
 886       }
 887     }
 888     ArtField** resolved_fields = dex_cache->GetResolvedFields();
 889     for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
 890       ArtField* field = mirror::DexCache::GetElementPtrSize(resolved_fields, i, target_ptr_size_);
 891       if (field != nullptr && !KeepClass(field->GetDeclaringClass())) {
 892         dex_cache->SetResolvedField(i, nullptr, target_ptr_size_);
 893       }
 894     }
 895     // Clean the dex field. It might have been populated during the initialization phase, but
 896     // contains data only valid during a real run.
 897     dex_cache->SetFieldObject<false>(mirror::DexCache::DexOffset(), nullptr);
 898   }
 899
 900   // Drop the array class cache in the ClassLinker, as these are roots holding those classes live.
 901   class_linker->DropFindArrayClassCache();
 902
 903   // Clear to save RAM.
 904   prune_class_memo_.clear();
 905 }
 906
 907 void ImageWriter::CheckNonImageClassesRemoved() {
 908   if (compiler_driver_.GetImageClasses() != nullptr) {
 909     gc::Heap* heap = Runtime::Current()->GetHeap();
 910     heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
 911   }
 912 }
 913
 914 void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
 915   ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
 916   if (obj->IsClass() && !image_writer->IsInBootImage(obj)) {
 917     Class* klass = obj->AsClass();
 918     if (!image_writer->KeepClass(klass)) {
 919       image_writer->DumpImageClasses();
 920       std::string temp;
 921       CHECK(image_writer->KeepClass(klass)) << klass->GetDescriptor(&temp)
 922                                             << " " << PrettyDescriptor(klass);
 923     }
 924   }
 925 }
 926
 927 void ImageWriter::DumpImageClasses() {
 928   auto image_classes = compiler_driver_.GetImageClasses();
 929   CHECK(image_classes != nullptr);
 930   for (const std::string& image_class : *image_classes) {
 931     LOG(INFO) << " " << image_class;
 932   }
 933 }
 934
 935 mirror::String* ImageWriter::FindInternedString(mirror::String* string) {
 936   Thread* const self = Thread::Current();
 937   for (const ImageInfo& image_info : image_infos_) {
 938     mirror::String* const found = image_info.intern_table_->LookupStrong(self, string);
 939     DCHECK(image_info.intern_table_->LookupWeak(self, string) == nullptr)
 940         << string->ToModifiedUtf8();
 941     if (found != nullptr) {
 942       return found;
 943     }
 944   }
 945   if (compile_app_image_) {
 946     Runtime* const runtime = Runtime::Current();
 947     mirror::String* found = runtime->GetInternTable()->LookupStrong(self, string);
 948     // If we found it in the runtime intern table it could either be in the boot image or interned
 949     // during app image compilation. If it was in the boot image return that, otherwise return null
 950     // since it belongs to another image space.
 951     if (found != nullptr && runtime->GetHeap()->ObjectIsInBootImageSpace(found)) {
 952       return found;
 953     }
 954     DCHECK(runtime->GetInternTable()->LookupWeak(self, string) == nullptr)
 955         << string->ToModifiedUtf8();
 956   }
 957   return nullptr;
 958 }
 959
 960 void ImageWriter::CalculateObjectBinSlots(Object* obj) {
 961   DCHECK(obj != nullptr);
 962   // if it is a string, we want to intern it if its not interned.
 963   if (obj->GetClass()->IsStringClass()) {
 964     size_t oat_index = GetOatIndex(obj);
 965     ImageInfo& image_info = GetImageInfo(oat_index);
 966
 967     // we must be an interned string that was forward referenced and already assigned
 968     if (IsImageBinSlotAssigned(obj)) {
 969       DCHECK_EQ(obj, FindInternedString(obj->AsString()));
 970       return;
 971     }
 972     // Need to check if the string is already interned in another image info so that we don't have
 973     // the intern tables of two different images contain the same string.
 974     mirror::String* interned = FindInternedString(obj->AsString());
 975     if (interned == nullptr) {
 976       // Not in another image space, insert to our table.
 977       interned = image_info.intern_table_->InternStrongImageString(obj->AsString());
 978     }
 979     if (obj != interned) {
 980       if (!IsImageBinSlotAssigned(interned)) {
 981         // interned obj is after us, allocate its location early
 982         AssignImageBinSlot(interned);
 983       }
 984       // point those looking for this object to the interned version.
 985       SetImageBinSlot(obj, GetImageBinSlot(interned));
 986       return;
 987     }
 988     // else (obj == interned), nothing to do but fall through to the normal case
 989   }
 990
 991   AssignImageBinSlot(obj);
 992 }
 993
 994 ObjectArray<Object>* ImageWriter::CreateImageRoots(size_t oat_index) const {
 995   Runtime* runtime = Runtime::Current();
 996   ClassLinker* class_linker = runtime->GetClassLinker();
 997   Thread* self = Thread::Current();
 998   StackHandleScope<3> hs(self);
 999   Handle<Class> object_array_class(hs.NewHandle(
1000       class_linker->FindSystemClass(self, "[Ljava/lang/Object;")));
1001
1002   std::unordered_set<const DexFile*> image_dex_files;
1003   for (auto& pair : dex_file_oat_index_map_) {
1004     const DexFile* image_dex_file = pair.first;
1005     size_t image_oat_index = pair.second;
1006     if (oat_index == image_oat_index) {
1007       image_dex_files.insert(image_dex_file);
1008     }
1009   }
1010
1011   // build an Object[] of all the DexCaches used in the source_space_.
1012   // Since we can't hold the dex lock when allocating the dex_caches
1013   // ObjectArray, we lock the dex lock twice, first to get the number
1014   // of dex caches first and then lock it again to copy the dex
1015   // caches. We check that the number of dex caches does not change.
1016   size_t dex_cache_count = 0;
1017   {
1018     ReaderMutexLock mu(self, *class_linker->DexLock());
1019     // Count number of dex caches not in the boot image.
1020     for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
1021       mirror::DexCache* dex_cache =
1022           down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
1023       const DexFile* dex_file = dex_cache->GetDexFile();
1024       if (!IsInBootImage(dex_cache)) {
1025         dex_cache_count += image_dex_files.find(dex_file) != image_dex_files.end() ? 1u : 0u;
1026       }
1027     }
1028   }
1029   Handle<ObjectArray<Object>> dex_caches(
1030       hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(), dex_cache_count)));
1031   CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array.";
1032   {
1033     ReaderMutexLock mu(self, *class_linker->DexLock());
1034     size_t non_image_dex_caches = 0;
1035     // Re-count number of non image dex caches.
1036     for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
1037       mirror::DexCache* dex_cache =
1038           down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
1039       const DexFile* dex_file = dex_cache->GetDexFile();
1040       if (!IsInBootImage(dex_cache)) {
1041         non_image_dex_caches += image_dex_files.find(dex_file) != image_dex_files.end() ? 1u : 0u;
1042       }
1043     }
1044     CHECK_EQ(dex_cache_count, non_image_dex_caches)
1045         << "The number of non-image dex caches changed.";
1046     size_t i = 0;
1047     for (const ClassLinker::DexCacheData& data : class_linker->GetDexCachesData()) {
1048       mirror::DexCache* dex_cache =
1049           down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root));
1050       const DexFile* dex_file = dex_cache->GetDexFile();
1051       if (!IsInBootImage(dex_cache) && image_dex_files.find(dex_file) != image_dex_files.end()) {
1052         dex_caches->Set<false>(i, dex_cache);
1053         ++i;
1054       }
1055     }
1056   }
1057
1058   // build an Object[] of the roots needed to restore the runtime
1059   auto image_roots(hs.NewHandle(
1060       ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
1061   image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get());
1062   image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
1063   for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
1064     CHECK(image_roots->Get(i) != nullptr);
1065   }
1066   return image_roots.Get();
1067 }
1068
1069 // Walk instance fields of the given Class. Separate function to allow recursion on the super
1070 // class.
1071 void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
1072   // Visit fields of parent classes first.
1073   StackHandleScope<1> hs(Thread::Current());
1074   Handle<mirror::Class> h_class(hs.NewHandle(klass));
1075   mirror::Class* super = h_class->GetSuperClass();
1076   if (super != nullptr) {
1077     WalkInstanceFields(obj, super);
1078   }
1079   //
1080   size_t num_reference_fields = h_class->NumReferenceInstanceFields();
1081   MemberOffset field_offset = h_class->GetFirstReferenceInstanceFieldOffset();
1082   for (size_t i = 0; i < num_reference_fields; ++i) {
1083     mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
1084     if (value != nullptr) {
1085       WalkFieldsInOrder(value);
1086     }
1087     field_offset = MemberOffset(field_offset.Uint32Value() +
1088                                 sizeof(mirror::HeapReference<mirror::Object>));
1089   }
1090 }
1091
1092 // For an unvisited object, visit it then all its children found via fields.
1093 void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
1094   if (IsInBootImage(obj)) {
1095     // Object is in the image, don't need to fix it up.
1096     return;
1097   }
1098   // Use our own visitor routine (instead of GC visitor) to get better locality between
1099   // an object and its fields
1100   if (!IsImageBinSlotAssigned(obj)) {
1101     // Walk instance fields of all objects
1102     StackHandleScope<2> hs(Thread::Current());
1103     Handle<mirror::Object> h_obj(hs.NewHandle(obj));
1104     Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass()));
1105     // visit the object itself.
1106     CalculateObjectBinSlots(h_obj.Get());
1107     WalkInstanceFields(h_obj.Get(), klass.Get());
1108     // Walk static fields of a Class.
1109     if (h_obj->IsClass()) {
1110       size_t num_reference_static_fields = klass->NumReferenceStaticFields();
1111       MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset(target_ptr_size_);
1112       for (size_t i = 0; i < num_reference_static_fields; ++i) {
1113         mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
1114         if (value != nullptr) {
1115           WalkFieldsInOrder(value);
1116         }
1117         field_offset = MemberOffset(field_offset.Uint32Value() +
1118                                     sizeof(mirror::HeapReference<mirror::Object>));
1119       }
1120       // Visit and assign offsets for fields and field arrays.
1121       auto* as_klass = h_obj->AsClass();
1122       mirror::DexCache* dex_cache = as_klass->GetDexCache();
1123       DCHECK_NE(klass->GetStatus(), mirror::Class::kStatusError);
1124       if (compile_app_image_) {
1125         // Extra sanity, no boot loader classes should be left!
1126         CHECK(!IsBootClassLoaderClass(as_klass)) << PrettyClass(as_klass);
1127       }
1128       LengthPrefixedArray<ArtField>* fields[] = {
1129           as_klass->GetSFieldsPtr(), as_klass->GetIFieldsPtr(),
1130       };
1131       size_t oat_index = GetOatIndexForDexCache(dex_cache);
1132       ImageInfo& image_info = GetImageInfo(oat_index);
1133       {
1134         // Note: This table is only accessed from the image writer, so the lock is technically
1135         // unnecessary.
1136         WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
1137         // Insert in the class table for this iamge.
1138         image_info.class_table_->Insert(as_klass);
1139       }
1140       for (LengthPrefixedArray<ArtField>* cur_fields : fields) {
1141         // Total array length including header.
1142         if (cur_fields != nullptr) {
1143           const size_t header_size = LengthPrefixedArray<ArtField>::ComputeSize(0);
1144           // Forward the entire array at once.
1145           auto it = native_object_relocations_.find(cur_fields);
1146           CHECK(it == native_object_relocations_.end()) << "Field array " << cur_fields
1147                                                   << " already forwarded";
1148           size_t& offset = image_info.bin_slot_sizes_[kBinArtField];
1149           DCHECK(!IsInBootImage(cur_fields));
1150           native_object_relocations_.emplace(
1151               cur_fields,
1152               NativeObjectRelocation {
1153                   oat_index, offset, kNativeObjectRelocationTypeArtFieldArray
1154               });
1155           offset += header_size;
1156           // Forward individual fields so that we can quickly find where they belong.
1157           for (size_t i = 0, count = cur_fields->size(); i < count; ++i) {
1158             // Need to forward arrays separate of fields.
1159             ArtField* field = &cur_fields->At(i);
1160             auto it2 = native_object_relocations_.find(field);
1161             CHECK(it2 == native_object_relocations_.end()) << "Field at index=" << i
1162                 << " already assigned " << PrettyField(field) << " static=" << field->IsStatic();
1163             DCHECK(!IsInBootImage(field));
1164             native_object_relocations_.emplace(
1165                 field,
1166                 NativeObjectRelocation { oat_index, offset, kNativeObjectRelocationTypeArtField });
1167             offset += sizeof(ArtField);
1168           }
1169         }
1170       }
1171       // Visit and assign offsets for methods.
1172       size_t num_methods = as_klass->NumMethods();
1173       if (num_methods != 0) {
1174         bool any_dirty = false;
1175         for (auto& m : as_klass->GetMethods(target_ptr_size_)) {
1176           if (WillMethodBeDirty(&m)) {
1177             any_dirty = true;
1178             break;
1179           }
1180         }
1181         NativeObjectRelocationType type = any_dirty
1182             ? kNativeObjectRelocationTypeArtMethodDirty
1183             : kNativeObjectRelocationTypeArtMethodClean;
1184         Bin bin_type = BinTypeForNativeRelocationType(type);
1185         // Forward the entire array at once, but header first.
1186         const size_t method_alignment = ArtMethod::Alignment(target_ptr_size_);
1187         const size_t method_size = ArtMethod::Size(target_ptr_size_);
1188         const size_t header_size = LengthPrefixedArray<ArtMethod>::ComputeSize(0,
1189                                                                                method_size,
1190                                                                                method_alignment);
1191         LengthPrefixedArray<ArtMethod>* array = as_klass->GetMethodsPtr();
1192         auto it = native_object_relocations_.find(array);
1193         CHECK(it == native_object_relocations_.end())
1194             << "Method array " << array << " already forwarded";
1195         size_t& offset = image_info.bin_slot_sizes_[bin_type];
1196         DCHECK(!IsInBootImage(array));
1197         native_object_relocations_.emplace(array,
1198             NativeObjectRelocation {
1199                 oat_index,
1200                 offset,
1201                 any_dirty ? kNativeObjectRelocationTypeArtMethodArrayDirty
1202                           : kNativeObjectRelocationTypeArtMethodArrayClean });
1203         offset += header_size;
1204         for (auto& m : as_klass->GetMethods(target_ptr_size_)) {
1205           AssignMethodOffset(&m, type, oat_index);
1206         }
1207         (any_dirty ? dirty_methods_ : clean_methods_) += num_methods;
1208       }
1209     } else if (h_obj->IsObjectArray()) {
1210       // Walk elements of an object array.
1211       int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength();
1212       for (int32_t i = 0; i < length; i++) {
1213         mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>();
1214         mirror::Object* value = obj_array->Get(i);
1215         if (value != nullptr) {
1216           WalkFieldsInOrder(value);
1217         }
1218       }
1219     } else if (h_obj->IsClassLoader()) {
1220       // Register the class loader if it has a class table.
1221       // The fake boot class loader should not get registered and we should end up with only one
1222       // class loader.
1223       mirror::ClassLoader* class_loader = h_obj->AsClassLoader();
1224       if (class_loader->GetClassTable() != nullptr) {
1225         class_loaders_.insert(class_loader);
1226       }
1227     }
1228   }
1229 }
1230
1231 void ImageWriter::AssignMethodOffset(ArtMethod* method,
1232                                      NativeObjectRelocationType type,
1233                                      size_t oat_index) {
1234   DCHECK(!IsInBootImage(method));
1235   auto it = native_object_relocations_.find(method);
1236   CHECK(it == native_object_relocations_.end()) << "Method " << method << " already assigned "
1237       << PrettyMethod(method);
1238   ImageInfo& image_info = GetImageInfo(oat_index);
1239   size_t& offset = image_info.bin_slot_sizes_[BinTypeForNativeRelocationType(type)];
1240   native_object_relocations_.emplace(method, NativeObjectRelocation { oat_index, offset, type });
1241   offset += ArtMethod::Size(target_ptr_size_);
1242 }
1243
1244 void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
1245   ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
1246   DCHECK(writer != nullptr);
1247   writer->WalkFieldsInOrder(obj);
1248 }
1249
1250 void ImageWriter::UnbinObjectsIntoOffsetCallback(mirror::Object* obj, void* arg) {
1251   ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
1252   DCHECK(writer != nullptr);
1253   if (!writer->IsInBootImage(obj)) {
1254     writer->UnbinObjectsIntoOffset(obj);
1255   }
1256 }
1257
1258 void ImageWriter::UnbinObjectsIntoOffset(mirror::Object* obj) {
1259   DCHECK(!IsInBootImage(obj));
1260   CHECK(obj != nullptr);
1261
1262   // We know the bin slot, and the total bin sizes for all objects by now,
1263   // so calculate the object's final image offset.
1264
1265   DCHECK(IsImageBinSlotAssigned(obj));
1266   BinSlot bin_slot = GetImageBinSlot(obj);
1267   // Change the lockword from a bin slot into an offset
1268   AssignImageOffset(obj, bin_slot);
1269 }
1270
1271 void ImageWriter::CalculateNewObjectOffsets() {
1272   Thread* const self = Thread::Current();
1273   StackHandleScopeCollection handles(self);
1274   std::vector<Handle<ObjectArray<Object>>> image_roots;
1275   for (size_t i = 0, size = oat_filenames_.size(); i != size; ++i) {
1276     image_roots.push_back(handles.NewHandle(CreateImageRoots(i)));
1277   }
1278
1279   auto* runtime = Runtime::Current();
1280   auto* heap = runtime->GetHeap();
1281
1282   // Leave space for the header, but do not write it yet, we need to
1283   // know where image_roots is going to end up
1284   image_objects_offset_begin_ = RoundUp(sizeof(ImageHeader), kObjectAlignment);  // 64-bit-alignment
1285
1286   // Clear any pre-existing monitors which may have been in the monitor words, assign bin slots.
1287   heap->VisitObjects(WalkFieldsCallback, this);
1288   // Write the image runtime methods.
1289   image_methods_[ImageHeader::kResolutionMethod] = runtime->GetResolutionMethod();
1290   image_methods_[ImageHeader::kImtConflictMethod] = runtime->GetImtConflictMethod();
1291   image_methods_[ImageHeader::kImtUnimplementedMethod] = runtime->GetImtUnimplementedMethod();
1292   image_methods_[ImageHeader::kCalleeSaveMethod] = runtime->GetCalleeSaveMethod(Runtime::kSaveAll);
1293   image_methods_[ImageHeader::kRefsOnlySaveMethod] =
1294       runtime->GetCalleeSaveMethod(Runtime::kRefsOnly);
1295   image_methods_[ImageHeader::kRefsAndArgsSaveMethod] =
1296       runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
1297
1298   // Add room for fake length prefixed array for holding the image methods.
1299   const auto image_method_type = kNativeObjectRelocationTypeArtMethodArrayClean;
1300   auto it = native_object_relocations_.find(&image_method_array_);
1301   CHECK(it == native_object_relocations_.end());
1302   ImageInfo& default_image_info = GetImageInfo(GetDefaultOatIndex());
1303   size_t& offset =
1304       default_image_info.bin_slot_sizes_[BinTypeForNativeRelocationType(image_method_type)];
1305   if (!compile_app_image_) {
1306     native_object_relocations_.emplace(&image_method_array_,
1307         NativeObjectRelocation { GetDefaultOatIndex(), offset, image_method_type });
1308   }
1309   size_t method_alignment = ArtMethod::Alignment(target_ptr_size_);
1310   const size_t array_size = LengthPrefixedArray<ArtMethod>::ComputeSize(
1311       0, ArtMethod::Size(target_ptr_size_), method_alignment);
1312   CHECK_ALIGNED_PARAM(array_size, method_alignment);
1313   offset += array_size;
1314   for (auto* m : image_methods_) {
1315     CHECK(m != nullptr);
1316     CHECK(m->IsRuntimeMethod());
1317     DCHECK_EQ(compile_app_image_, IsInBootImage(m)) << "Trampolines should be in boot image";
1318     if (!IsInBootImage(m)) {
1319       AssignMethodOffset(m, kNativeObjectRelocationTypeArtMethodClean, GetDefaultOatIndex());
1320     }
1321   }
1322   // Calculate size of the dex cache arrays slot and prepare offsets.
1323   PrepareDexCacheArraySlots();
1324
1325   // Calculate the sizes of the intern tables and class tables.
1326   for (ImageInfo& image_info : image_infos_) {
1327     // Calculate how big the intern table will be after being serialized.
1328     InternTable* const intern_table = image_info.intern_table_.get();
1329     CHECK_EQ(intern_table->WeakSize(), 0u) << " should have strong interned all the strings";
1330     image_info.intern_table_bytes_ = intern_table->WriteToMemory(nullptr);
1331     // Calculate the size of the class table.
1332     ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_);
1333     image_info.class_table_bytes_ += image_info.class_table_->WriteToMemory(nullptr);
1334   }
1335
1336   // Calculate bin slot offsets.
1337   for (ImageInfo& image_info : image_infos_) {
1338     size_t bin_offset = image_objects_offset_begin_;
1339     for (size_t i = 0; i != kBinSize; ++i) {
1340       image_info.bin_slot_offsets_[i] = bin_offset;
1341       bin_offset += image_info.bin_slot_sizes_[i];
1342       if (i == kBinArtField) {
1343         static_assert(kBinArtField + 1 == kBinArtMethodClean, "Methods follow fields.");
1344         static_assert(alignof(ArtField) == 4u, "ArtField alignment is 4.");
1345         DCHECK_ALIGNED(bin_offset, 4u);
1346         DCHECK(method_alignment == 4u || method_alignment == 8u);
1347         bin_offset = RoundUp(bin_offset, method_alignment);
1348       }
1349     }
1350     // NOTE: There may be additional padding between the bin slots and the intern table.
1351     DCHECK_EQ(image_info.image_end_,
1352               GetBinSizeSum(image_info, kBinMirrorCount) + image_objects_offset_begin_);
1353   }
1354
1355   // Calculate image offsets.
1356   size_t image_offset = 0;
1357   for (ImageInfo& image_info : image_infos_) {
1358     image_info.image_begin_ = global_image_begin_ + image_offset;
1359     image_info.image_offset_ = image_offset;
1360     ImageSection unused_sections[ImageHeader::kSectionCount];
1361     image_info.image_size_ = RoundUp(
1362         image_info.CreateImageSections(target_ptr_size_, unused_sections),
1363         kPageSize);
1364     // There should be no gaps until the next image.
1365     image_offset += image_info.image_size_;
1366   }
1367
1368   // Transform each object's bin slot into an offset which will be used to do the final copy.
1369   heap->VisitObjects(UnbinObjectsIntoOffsetCallback, this);
1370
1371   // DCHECK_EQ(image_end_, GetBinSizeSum(kBinMirrorCount) + image_objects_offset_begin_);
1372
1373   size_t i = 0;
1374   for (ImageInfo& image_info : image_infos_) {
1375     image_info.image_roots_address_ = PointerToLowMemUInt32(GetImageAddress(image_roots[i].Get()));
1376     i++;
1377   }
1378
1379   // Update the native relocations by adding their bin sums.
1380   for (auto& pair : native_object_relocations_) {
1381     NativeObjectRelocation& relocation = pair.second;
1382     Bin bin_type = BinTypeForNativeRelocationType(relocation.type);
1383     ImageInfo& image_info = GetImageInfo(relocation.oat_index);
1384     relocation.offset += image_info.bin_slot_offsets_[bin_type];
1385   }
1386
1387   // Note that image_info.image_end_ is left at end of used mirror object section.
1388 }
1389
1390 size_t ImageWriter::ImageInfo::CreateImageSections(size_t target_ptr_size,
1391                                                    ImageSection* out_sections) const {
1392   DCHECK(out_sections != nullptr);
1393   // Objects section
1394   auto* objects_section = &out_sections[ImageHeader::kSectionObjects];
1395   *objects_section = ImageSection(0u, image_end_);
1396   size_t cur_pos = objects_section->End();
1397   // Add field section.
1398   auto* field_section = &out_sections[ImageHeader::kSectionArtFields];
1399   *field_section = ImageSection(cur_pos, bin_slot_sizes_[kBinArtField]);
1400   CHECK_EQ(bin_slot_offsets_[kBinArtField], field_section->Offset());
1401   cur_pos = field_section->End();
1402   // Round up to the alignment the required by the method section.
1403   cur_pos = RoundUp(cur_pos, ArtMethod::Alignment(target_ptr_size));
1404   // Add method section.
1405   auto* methods_section = &out_sections[ImageHeader::kSectionArtMethods];
1406   *methods_section = ImageSection(cur_pos,
1407                                   bin_slot_sizes_[kBinArtMethodClean] +
1408                                       bin_slot_sizes_[kBinArtMethodDirty]);
1409   CHECK_EQ(bin_slot_offsets_[kBinArtMethodClean], methods_section->Offset());
1410   cur_pos = methods_section->End();
1411   // Add dex cache arrays section.
1412   auto* dex_cache_arrays_section = &out_sections[ImageHeader::kSectionDexCacheArrays];
1413   *dex_cache_arrays_section = ImageSection(cur_pos, bin_slot_sizes_[kBinDexCacheArray]);
1414   CHECK_EQ(bin_slot_offsets_[kBinDexCacheArray], dex_cache_arrays_section->Offset());
1415   cur_pos = dex_cache_arrays_section->End();
1416   // Round up to the alignment the string table expects. See HashSet::WriteToMemory.
1417   cur_pos = RoundUp(cur_pos, sizeof(uint64_t));
1418   // Calculate the size of the interned strings.
1419   auto* interned_strings_section = &out_sections[ImageHeader::kSectionInternedStrings];
1420   *interned_strings_section = ImageSection(cur_pos, intern_table_bytes_);
1421   cur_pos = interned_strings_section->End();
1422   // Round up to the alignment the class table expects. See HashSet::WriteToMemory.
1423   cur_pos = RoundUp(cur_pos, sizeof(uint64_t));
1424   // Calculate the size of the class table section.
1425   auto* class_table_section = &out_sections[ImageHeader::kSectionClassTable];
1426   *class_table_section = ImageSection(cur_pos, class_table_bytes_);
1427   cur_pos = class_table_section->End();
1428   // Image end goes right before the start of the image bitmap.
1429   return cur_pos;
1430 }
1431
1432 void ImageWriter::CreateHeader(size_t oat_index) {
1433   ImageInfo& image_info = GetImageInfo(oat_index);
1434   const uint8_t* oat_file_begin = image_info.oat_file_begin_;
1435   const uint8_t* oat_file_end = oat_file_begin + image_info.oat_loaded_size_;
1436   const uint8_t* oat_data_end = image_info.oat_data_begin_ + image_info.oat_size_;
1437
1438   // Create the image sections.
1439   ImageSection sections[ImageHeader::kSectionCount];
1440   const size_t image_end = image_info.CreateImageSections(target_ptr_size_, sections);
1441
1442   // Finally bitmap section.
1443   const size_t bitmap_bytes = image_info.image_bitmap_->Size();
1444   auto* bitmap_section = &sections[ImageHeader::kSectionImageBitmap];
1445   *bitmap_section = ImageSection(RoundUp(image_end, kPageSize), RoundUp(bitmap_bytes, kPageSize));
1446   if (VLOG_IS_ON(compiler)) {
1447     LOG(INFO) << "Creating header for " << oat_filenames_[oat_index];
1448     size_t idx = 0;
1449     for (const ImageSection& section : sections) {
1450       LOG(INFO) << static_cast<ImageHeader::ImageSections>(idx) << " " << section;
1451       ++idx;
1452     }
1453     LOG(INFO) << "Methods: clean=" << clean_methods_ << " dirty=" << dirty_methods_;
1454     LOG(INFO) << "Image roots address=" << std::hex << image_info.image_roots_address_ << std::dec;
1455     LOG(INFO) << "Image begin=" << std::hex << reinterpret_cast<uintptr_t>(global_image_begin_)
1456               << " Image offset=" << image_info.image_offset_ << std::dec;
1457     LOG(INFO) << "Oat file begin=" << std::hex << reinterpret_cast<uintptr_t>(oat_file_begin)
1458               << " Oat data begin=" << reinterpret_cast<uintptr_t>(image_info.oat_data_begin_)
1459               << " Oat data end=" << reinterpret_cast<uintptr_t>(oat_data_end)
1460               << " Oat file end=" << reinterpret_cast<uintptr_t>(oat_file_end);
1461   }
1462   // Store boot image info for app image so that we can relocate.
1463   uint32_t boot_image_begin = 0;
1464   uint32_t boot_image_end = 0;
1465   uint32_t boot_oat_begin = 0;
1466   uint32_t boot_oat_end = 0;
1467   gc::Heap* const heap = Runtime::Current()->GetHeap();
1468   heap->GetBootImagesSize(&boot_image_begin, &boot_image_end, &boot_oat_begin, &boot_oat_end);
1469
1470   // Create the header, leave 0 for data size since we will fill this in as we are writing the
1471   // image.
1472   new (image_info.image_->Begin()) ImageHeader(PointerToLowMemUInt32(image_info.image_begin_),
1473                                                image_end,
1474                                                sections,
1475                                                image_info.image_roots_address_,
1476                                                image_info.oat_checksum_,
1477                                                PointerToLowMemUInt32(oat_file_begin),
1478                                                PointerToLowMemUInt32(image_info.oat_data_begin_),
1479                                                PointerToLowMemUInt32(oat_data_end),
1480                                                PointerToLowMemUInt32(oat_file_end),
1481                                                boot_image_begin,
1482                                                boot_image_end - boot_image_begin,
1483                                                boot_oat_begin,
1484                                                boot_oat_end - boot_oat_begin,
1485                                                target_ptr_size_,
1486                                                compile_pic_,
1487                                                /*is_pic*/compile_app_image_,
1488                                                image_storage_mode_,
1489                                                /*data_size*/0u);
1490 }
1491
1492 ArtMethod* ImageWriter::GetImageMethodAddress(ArtMethod* method) {
1493   auto it = native_object_relocations_.find(method);
1494   CHECK(it != native_object_relocations_.end()) << PrettyMethod(method) << " @ " << method;
1495   size_t oat_index = GetOatIndex(method->GetDexCache());
1496   ImageInfo& image_info = GetImageInfo(oat_index);
1497   CHECK_GE(it->second.offset, image_info.image_end_) << "ArtMethods should be after Objects";
1498   return reinterpret_cast<ArtMethod*>(image_info.image_begin_ + it->second.offset);
1499 }
1500
1501 class FixupRootVisitor : public RootVisitor {
1502  public:
1503   explicit FixupRootVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {
1504   }
1505
1506   void VisitRoots(mirror::Object*** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED)
1507       OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
1508     for (size_t i = 0; i < count; ++i) {
1509       *roots[i] = image_writer_->GetImageAddress(*roots[i]);
1510     }
1511   }
1512
1513   void VisitRoots(mirror::CompressedReference<mirror::Object>** roots, size_t count,
1514                   const RootInfo& info ATTRIBUTE_UNUSED)
1515       OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) {
1516     for (size_t i = 0; i < count; ++i) {
1517       roots[i]->Assign(image_writer_->GetImageAddress(roots[i]->AsMirrorPtr()));
1518     }
1519   }
1520
1521  private:
1522   ImageWriter* const image_writer_;
1523 };
1524
1525 void ImageWriter::CopyAndFixupNativeData(size_t oat_index) {
1526   ImageInfo& image_info = GetImageInfo(oat_index);
1527   // Copy ArtFields and methods to their locations and update the array for convenience.
1528   for (auto& pair : native_object_relocations_) {
1529     NativeObjectRelocation& relocation = pair.second;
1530     // Only work with fields and methods that are in the current oat file.
1531     if (relocation.oat_index != oat_index) {
1532       continue;
1533     }
1534     auto* dest = image_info.image_->Begin() + relocation.offset;
1535     DCHECK_GE(dest, image_info.image_->Begin() + image_info.image_end_);
1536     DCHECK(!IsInBootImage(pair.first));
1537     switch (relocation.type) {
1538       case kNativeObjectRelocationTypeArtField: {
1539         memcpy(dest, pair.first, sizeof(ArtField));
1540         reinterpret_cast<ArtField*>(dest)->SetDeclaringClass(
1541             GetImageAddress(reinterpret_cast<ArtField*>(pair.first)->GetDeclaringClass()));
1542         break;
1543       }
1544       case kNativeObjectRelocationTypeArtMethodClean:
1545       case kNativeObjectRelocationTypeArtMethodDirty: {
1546         CopyAndFixupMethod(reinterpret_cast<ArtMethod*>(pair.first),
1547                            reinterpret_cast<ArtMethod*>(dest),
1548                            image_info);
1549         break;
1550       }
1551       // For arrays, copy just the header since the elements will get copied by their corresponding
1552       // relocations.
1553       case kNativeObjectRelocationTypeArtFieldArray: {
1554         memcpy(dest, pair.first, LengthPrefixedArray<ArtField>::ComputeSize(0));
1555         break;
1556       }
1557       case kNativeObjectRelocationTypeArtMethodArrayClean:
1558       case kNativeObjectRelocationTypeArtMethodArrayDirty: {
1559         size_t size = ArtMethod::Size(target_ptr_size_);
1560         size_t alignment = ArtMethod::Alignment(target_ptr_size_);
1561         memcpy(dest, pair.first, LengthPrefixedArray<ArtMethod>::ComputeSize(0, size, alignment));
1562         // Clear padding to avoid non-deterministic data in the image (and placate valgrind).
1563         reinterpret_cast<LengthPrefixedArray<ArtMethod>*>(dest)->ClearPadding(size, alignment);
1564         break;
1565       }
1566       case kNativeObjectRelocationTypeDexCacheArray:
1567         // Nothing to copy here, everything is done in FixupDexCache().
1568         break;
1569     }
1570   }
1571   // Fixup the image method roots.
1572   auto* image_header = reinterpret_cast<ImageHeader*>(image_info.image_->Begin());
1573   const ImageSection& methods_section = image_header->GetMethodsSection();
1574   for (size_t i = 0; i < ImageHeader::kImageMethodsCount; ++i) {
1575     ArtMethod* method = image_methods_[i];
1576     CHECK(method != nullptr);
1577     // Only place runtime methods in the image of the default oat file.
1578     if (method->IsRuntimeMethod() && oat_index != GetDefaultOatIndex()) {
1579       continue;
1580     }
1581     if (!IsInBootImage(method)) {
1582       auto it = native_object_relocations_.find(method);
1583       CHECK(it != native_object_relocations_.end()) << "No forwarding for " << PrettyMethod(method);
1584       NativeObjectRelocation& relocation = it->second;
1585       CHECK(methods_section.Contains(relocation.offset)) << relocation.offset << " not in "
1586           << methods_section;
1587       CHECK(relocation.IsArtMethodRelocation()) << relocation.type;
1588       method = reinterpret_cast<ArtMethod*>(global_image_begin_ + it->second.offset);
1589     }
1590     image_header->SetImageMethod(static_cast<ImageHeader::ImageMethod>(i), method);
1591   }
1592   FixupRootVisitor root_visitor(this);
1593
1594   // Write the intern table into the image.
1595   if (image_info.intern_table_bytes_ > 0) {
1596     const ImageSection& intern_table_section = image_header->GetImageSection(
1597         ImageHeader::kSectionInternedStrings);
1598     InternTable* const intern_table = image_info.intern_table_.get();
1599     uint8_t* const intern_table_memory_ptr =
1600         image_info.image_->Begin() + intern_table_section.Offset();
1601     const size_t intern_table_bytes = intern_table->WriteToMemory(intern_table_memory_ptr);
1602     CHECK_EQ(intern_table_bytes, image_info.intern_table_bytes_);
1603     // Fixup the pointers in the newly written intern table to contain image addresses.
1604     InternTable temp_intern_table;
1605     // Note that we require that ReadFromMemory does not make an internal copy of the elements so that
1606     // the VisitRoots() will update the memory directly rather than the copies.
1607     // This also relies on visit roots not doing any verification which could fail after we update
1608     // the roots to be the image addresses.
1609     temp_intern_table.AddTableFromMemory(intern_table_memory_ptr);
1610     CHECK_EQ(temp_intern_table.Size(), intern_table->Size());
1611     temp_intern_table.VisitRoots(&root_visitor, kVisitRootFlagAllRoots);
1612   }
1613   // Write the class table(s) into the image. class_table_bytes_ may be 0 if there are multiple
1614   // class loaders. Writing multiple class tables into the image is currently unsupported.
1615   if (image_info.class_table_bytes_ > 0u) {
1616     const ImageSection& class_table_section = image_header->GetImageSection(
1617         ImageHeader::kSectionClassTable);
1618     uint8_t* const class_table_memory_ptr =
1619         image_info.image_->Begin() + class_table_section.Offset();
1620     ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
1621
1622     ClassTable* table = image_info.class_table_.get();
1623     CHECK(table != nullptr);
1624     const size_t class_table_bytes = table->WriteToMemory(class_table_memory_ptr);
1625     CHECK_EQ(class_table_bytes, image_info.class_table_bytes_);
1626     // Fixup the pointers in the newly written class table to contain image addresses. See
1627     // above comment for intern tables.
1628     ClassTable temp_class_table;
1629     temp_class_table.ReadFromMemory(class_table_memory_ptr);
1630     CHECK_EQ(temp_class_table.NumZygoteClasses(), table->NumNonZygoteClasses() +
1631              table->NumZygoteClasses());
1632     BufferedRootVisitor<kDefaultBufferedRootCount> buffered_visitor(&root_visitor,
1633                                                                     RootInfo(kRootUnknown));
1634     temp_class_table.VisitRoots(buffered_visitor);
1635   }
1636 }
1637
1638 void ImageWriter::CopyAndFixupObjects() {
1639   gc::Heap* heap = Runtime::Current()->GetHeap();
1640   heap->VisitObjects(CopyAndFixupObjectsCallback, this);
1641   // Fix up the object previously had hash codes.
1642   for (const auto& hash_pair : saved_hashcode_map_) {
1643     Object* obj = hash_pair.first;
1644     DCHECK_EQ(obj->GetLockWord<kVerifyNone>(false).ReadBarrierState(), 0U);
1645     obj->SetLockWord<kVerifyNone>(LockWord::FromHashCode(hash_pair.second, 0U), false);
1646   }
1647   saved_hashcode_map_.clear();
1648 }
1649
1650 void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
1651   DCHECK(obj != nullptr);
1652   DCHECK(arg != nullptr);
1653   reinterpret_cast<ImageWriter*>(arg)->CopyAndFixupObject(obj);
1654 }
1655
1656 void ImageWriter::FixupPointerArray(mirror::Object* dst, mirror::PointerArray* arr,
1657                                     mirror::Class* klass, Bin array_type) {
1658   CHECK(klass->IsArrayClass());
1659   CHECK(arr->IsIntArray() || arr->IsLongArray()) << PrettyClass(klass) << " " << arr;
1660   // Fixup int and long pointers for the ArtMethod or ArtField arrays.
1661   const size_t num_elements = arr->GetLength();
1662   dst->SetClass(GetImageAddress(arr->GetClass()));
1663   auto* dest_array = down_cast<mirror::PointerArray*>(dst);
1664   for (size_t i = 0, count = num_elements; i < count; ++i) {
1665     void* elem = arr->GetElementPtrSize<void*>(i, target_ptr_size_);
1666     if (elem != nullptr && !IsInBootImage(elem)) {
1667       auto it = native_object_relocations_.find(elem);
1668       if (UNLIKELY(it == native_object_relocations_.end())) {
1669         if (it->second.IsArtMethodRelocation()) {
1670           auto* method = reinterpret_cast<ArtMethod*>(elem);
1671           LOG(FATAL) << "No relocation entry for ArtMethod " << PrettyMethod(method) << " @ "
1672               << method << " idx=" << i << "/" << num_elements << " with declaring class "
1673               << PrettyClass(method->GetDeclaringClass());
1674         } else {
1675           CHECK_EQ(array_type, kBinArtField);
1676           auto* field = reinterpret_cast<ArtField*>(elem);
1677           LOG(FATAL) << "No relocation entry for ArtField " << PrettyField(field) << " @ "
1678               << field << " idx=" << i << "/" << num_elements << " with declaring class "
1679               << PrettyClass(field->GetDeclaringClass());
1680         }
1681         UNREACHABLE();
1682       } else {
1683         ImageInfo& image_info = GetImageInfo(it->second.oat_index);
1684         elem = image_info.image_begin_ + it->second.offset;
1685       }
1686     }
1687     dest_array->SetElementPtrSize<false, true>(i, elem, target_ptr_size_);
1688   }
1689 }
1690
1691 void ImageWriter::CopyAndFixupObject(Object* obj) {
1692   if (IsInBootImage(obj)) {
1693     return;
1694   }
1695   size_t offset = GetImageOffset(obj);
1696   size_t oat_index = GetOatIndex(obj);
1697   ImageInfo& image_info = GetImageInfo(oat_index);
1698   auto* dst = reinterpret_cast<Object*>(image_info.image_->Begin() + offset);
1699   DCHECK_LT(offset, image_info.image_end_);
1700   const auto* src = reinterpret_cast<const uint8_t*>(obj);
1701
1702   image_info.image_bitmap_->Set(dst);  // Mark the obj as live.
1703
1704   const size_t n = obj->SizeOf();
1705   DCHECK_LE(offset + n, image_info.image_->Size());
1706   memcpy(dst, src, n);
1707
1708   // Write in a hash code of objects which have inflated monitors or a hash code in their monitor
1709   // word.
1710   const auto it = saved_hashcode_map_.find(obj);
1711   dst->SetLockWord(it != saved_hashcode_map_.end() ?
1712       LockWord::FromHashCode(it->second, 0u) : LockWord::Default(), false);
1713   FixupObject(obj, dst);
1714 }
1715
1716 // Rewrite all the references in the copied object to point to their image address equivalent
1717 class FixupVisitor {
1718  public:
1719   FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
1720   }
1721
1722   // Ignore class roots since we don't have a way to map them to the destination. These are handled
1723   // with other logic.
1724   void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root ATTRIBUTE_UNUSED)
1725       const {}
1726   void VisitRoot(mirror::CompressedReference<mirror::Object>* root ATTRIBUTE_UNUSED) const {}
1727
1728
1729   void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const
1730       REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
1731     Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset);
1732     // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
1733     // image.
1734     copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
1735         offset,
1736         image_writer_->GetImageAddress(ref));
1737   }
1738
1739   // java.lang.ref.Reference visitor.
1740   void operator()(mirror::Class* klass ATTRIBUTE_UNUSED, mirror::Reference* ref) const
1741       SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) {
1742     copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
1743         mirror::Reference::ReferentOffset(),
1744         image_writer_->GetImageAddress(ref->GetReferent()));
1745   }
1746
1747  protected:
1748   ImageWriter* const image_writer_;
1749   mirror::Object* const copy_;
1750 };
1751
1752 class FixupClassVisitor FINAL : public FixupVisitor {
1753  public:
1754   FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) {
1755   }
1756
1757   void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const
1758       REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
1759     DCHECK(obj->IsClass());
1760     FixupVisitor::operator()(obj, offset, /*is_static*/false);
1761   }
1762
1763   void operator()(mirror::Class* klass ATTRIBUTE_UNUSED,
1764                   mirror::Reference* ref ATTRIBUTE_UNUSED) const
1765       SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) {
1766     LOG(FATAL) << "Reference not expected here.";
1767   }
1768 };
1769
1770 uintptr_t ImageWriter::NativeOffsetInImage(void* obj) {
1771   DCHECK(obj != nullptr);
1772   DCHECK(!IsInBootImage(obj));
1773   auto it = native_object_relocations_.find(obj);
1774   CHECK(it != native_object_relocations_.end()) << obj << " spaces "
1775       << Runtime::Current()->GetHeap()->DumpSpaces();
1776   const NativeObjectRelocation& relocation = it->second;
1777   return relocation.offset;
1778 }
1779
1780 template <typename T>
1781 T* ImageWriter::NativeLocationInImage(T* obj) {
1782   if (obj == nullptr || IsInBootImage(obj)) {
1783     return obj;
1784   } else {
1785     auto it = native_object_relocations_.find(obj);
1786     CHECK(it != native_object_relocations_.end()) << obj << " spaces "
1787         << Runtime::Current()->GetHeap()->DumpSpaces();
1788     const NativeObjectRelocation& relocation = it->second;
1789     ImageInfo& image_info = GetImageInfo(relocation.oat_index);
1790     return reinterpret_cast<T*>(image_info.image_begin_ + relocation.offset);
1791   }
1792 }
1793
1794 template <typename T>
1795 T* ImageWriter::NativeCopyLocation(T* obj, mirror::DexCache* dex_cache) {
1796   if (obj == nullptr || IsInBootImage(obj)) {
1797     return obj;
1798   } else {
1799     size_t oat_index = GetOatIndexForDexCache(dex_cache);
1800     ImageInfo& image_info = GetImageInfo(oat_index);
1801     return reinterpret_cast<T*>(image_info.image_->Begin() + NativeOffsetInImage(obj));
1802   }
1803 }
1804
1805 class NativeLocationVisitor {
1806  public:
1807   explicit NativeLocationVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {}
1808
1809   template <typename T>
1810   T* operator()(T* ptr) const SHARED_REQUIRES(Locks::mutator_lock_) {
1811     return image_writer_->NativeLocationInImage(ptr);
1812   }
1813
1814  private:
1815   ImageWriter* const image_writer_;
1816 };
1817
1818 void ImageWriter::FixupClass(mirror::Class* orig, mirror::Class* copy) {
1819   orig->FixupNativePointers(copy, target_ptr_size_, NativeLocationVisitor(this));
1820   FixupClassVisitor visitor(this, copy);
1821   static_cast<mirror::Object*>(orig)->VisitReferences(visitor, visitor);
1822
1823   // Remove the clinitThreadId. This is required for image determinism.
1824   copy->SetClinitThreadId(static_cast<pid_t>(0));
1825 }
1826
1827 void ImageWriter::FixupObject(Object* orig, Object* copy) {
1828   DCHECK(orig != nullptr);
1829   DCHECK(copy != nullptr);
1830   if (kUseBakerOrBrooksReadBarrier) {
1831     orig->AssertReadBarrierPointer();
1832     if (kUseBrooksReadBarrier) {
1833       // Note the address 'copy' isn't the same as the image address of 'orig'.
1834       copy->SetReadBarrierPointer(GetImageAddress(orig));
1835       DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig));
1836     }
1837   }
1838   auto* klass = orig->GetClass();
1839   if (klass->IsIntArrayClass() || klass->IsLongArrayClass()) {
1840     // Is this a native pointer array?
1841     auto it = pointer_arrays_.find(down_cast<mirror::PointerArray*>(orig));
1842     if (it != pointer_arrays_.end()) {
1843       // Should only need to fixup every pointer array exactly once.
1844       FixupPointerArray(copy, down_cast<mirror::PointerArray*>(orig), klass, it->second);
1845       pointer_arrays_.erase(it);
1846       return;
1847     }
1848   }
1849   if (orig->IsClass()) {
1850     FixupClass(orig->AsClass<kVerifyNone>(), down_cast<mirror::Class*>(copy));
1851   } else {
1852     if (klass == mirror::Method::StaticClass() || klass == mirror::Constructor::StaticClass()) {
1853       // Need to go update the ArtMethod.
1854       auto* dest = down_cast<mirror::AbstractMethod*>(copy);
1855       auto* src = down_cast<mirror::AbstractMethod*>(orig);
1856       ArtMethod* src_method = src->GetArtMethod();
1857       auto it = native_object_relocations_.find(src_method);
1858       CHECK(it != native_object_relocations_.end())
1859           << "Missing relocation for AbstractMethod.artMethod " << PrettyMethod(src_method);
1860       dest->SetArtMethod(
1861           reinterpret_cast<ArtMethod*>(global_image_begin_ + it->second.offset));
1862     } else if (!klass->IsArrayClass()) {
1863       ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
1864       if (klass == class_linker->GetClassRoot(ClassLinker::kJavaLangDexCache)) {
1865         FixupDexCache(down_cast<mirror::DexCache*>(orig), down_cast<mirror::DexCache*>(copy));
1866       } else if (klass->IsClassLoaderClass()) {
1867         mirror::ClassLoader* copy_loader = down_cast<mirror::ClassLoader*>(copy);
1868         // If src is a ClassLoader, set the class table to null so that it gets recreated by the
1869         // ClassLoader.
1870         copy_loader->SetClassTable(nullptr);
1871         // Also set allocator to null to be safe. The allocator is created when we create the class
1872         // table. We also never expect to unload things in the image since they are held live as
1873         // roots.
1874         copy_loader->SetAllocator(nullptr);
1875       }
1876     }
1877     FixupVisitor visitor(this, copy);
1878     orig->VisitReferences(visitor, visitor);
1879   }
1880 }
1881
1882
1883 class ImageAddressVisitor {
1884  public:
1885   explicit ImageAddressVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {}
1886
1887   template <typename T>
1888   T* operator()(T* ptr) const SHARED_REQUIRES(Locks::mutator_lock_) {
1889     return image_writer_->GetImageAddress(ptr);
1890   }
1891
1892  private:
1893   ImageWriter* const image_writer_;
1894 };
1895
1896
1897 void ImageWriter::FixupDexCache(mirror::DexCache* orig_dex_cache,
1898                                 mirror::DexCache* copy_dex_cache) {
1899   // Though the DexCache array fields are usually treated as native pointers, we set the full
1900   // 64-bit values here, clearing the top 32 bits for 32-bit targets. The zero-extension is
1901   // done by casting to the unsigned type uintptr_t before casting to int64_t, i.e.
1902   //     static_cast<int64_t>(reinterpret_cast<uintptr_t>(image_begin_ + offset))).
1903   GcRoot<mirror::String>* orig_strings = orig_dex_cache->GetStrings();
1904   if (orig_strings != nullptr) {
1905     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::StringsOffset(),
1906                                                NativeLocationInImage(orig_strings),
1907                                                /*pointer size*/8u);
1908     orig_dex_cache->FixupStrings(NativeCopyLocation(orig_strings, orig_dex_cache),
1909                                  ImageAddressVisitor(this));
1910   }
1911   GcRoot<mirror::Class>* orig_types = orig_dex_cache->GetResolvedTypes();
1912   if (orig_types != nullptr) {
1913     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::ResolvedTypesOffset(),
1914                                                NativeLocationInImage(orig_types),
1915                                                /*pointer size*/8u);
1916     orig_dex_cache->FixupResolvedTypes(NativeCopyLocation(orig_types, orig_dex_cache),
1917                                        ImageAddressVisitor(this));
1918   }
1919   ArtMethod** orig_methods = orig_dex_cache->GetResolvedMethods();
1920   if (orig_methods != nullptr) {
1921     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::ResolvedMethodsOffset(),
1922                                                NativeLocationInImage(orig_methods),
1923                                                /*pointer size*/8u);
1924     ArtMethod** copy_methods = NativeCopyLocation(orig_methods, orig_dex_cache);
1925     for (size_t i = 0, num = orig_dex_cache->NumResolvedMethods(); i != num; ++i) {
1926       ArtMethod* orig = mirror::DexCache::GetElementPtrSize(orig_methods, i, target_ptr_size_);
1927       // NativeLocationInImage also handles runtime methods since these have relocation info.
1928       ArtMethod* copy = NativeLocationInImage(orig);
1929       mirror::DexCache::SetElementPtrSize(copy_methods, i, copy, target_ptr_size_);
1930     }
1931   }
1932   ArtField** orig_fields = orig_dex_cache->GetResolvedFields();
1933   if (orig_fields != nullptr) {
1934     copy_dex_cache->SetFieldPtrWithSize<false>(mirror::DexCache::ResolvedFieldsOffset(),
1935                                                NativeLocationInImage(orig_fields),
1936                                                /*pointer size*/8u);
1937     ArtField** copy_fields = NativeCopyLocation(orig_fields, orig_dex_cache);
1938     for (size_t i = 0, num = orig_dex_cache->NumResolvedFields(); i != num; ++i) {
1939       ArtField* orig = mirror::DexCache::GetElementPtrSize(orig_fields, i, target_ptr_size_);
1940       ArtField* copy = NativeLocationInImage(orig);
1941       mirror::DexCache::SetElementPtrSize(copy_fields, i, copy, target_ptr_size_);
1942     }
1943   }
1944
1945   // Remove the DexFile pointers. They will be fixed up when the runtime loads the oat file. Leaving
1946   // compiler pointers in here will make the output non-deterministic.
1947   copy_dex_cache->SetDexFile(nullptr);
1948 }
1949
1950 const uint8_t* ImageWriter::GetOatAddress(OatAddress type) const {
1951   DCHECK_LT(type, kOatAddressCount);
1952   // If we are compiling an app image, we need to use the stubs of the boot image.
1953   if (compile_app_image_) {
1954     // Use the current image pointers.
1955     const std::vector<gc::space::ImageSpace*>& image_spaces =
1956         Runtime::Current()->GetHeap()->GetBootImageSpaces();
1957     DCHECK(!image_spaces.empty());
1958     const OatFile* oat_file = image_spaces[0]->GetOatFile();
1959     CHECK(oat_file != nullptr);
1960     const OatHeader& header = oat_file->GetOatHeader();
1961     switch (type) {
1962       // TODO: We could maybe clean this up if we stored them in an array in the oat header.
1963       case kOatAddressQuickGenericJNITrampoline:
1964         return static_cast<const uint8_t*>(header.GetQuickGenericJniTrampoline());
1965       case kOatAddressInterpreterToInterpreterBridge:
1966         return static_cast<const uint8_t*>(header.GetInterpreterToInterpreterBridge());
1967       case kOatAddressInterpreterToCompiledCodeBridge:
1968         return static_cast<const uint8_t*>(header.GetInterpreterToCompiledCodeBridge());
1969       case kOatAddressJNIDlsymLookup:
1970         return static_cast<const uint8_t*>(header.GetJniDlsymLookup());
1971       case kOatAddressQuickIMTConflictTrampoline:
1972         return static_cast<const uint8_t*>(header.GetQuickImtConflictTrampoline());
1973       case kOatAddressQuickResolutionTrampoline:
1974         return static_cast<const uint8_t*>(header.GetQuickResolutionTrampoline());
1975       case kOatAddressQuickToInterpreterBridge:
1976         return static_cast<const uint8_t*>(header.GetQuickToInterpreterBridge());
1977       default:
1978         UNREACHABLE();
1979     }
1980   }
1981   const ImageInfo& primary_image_info = GetImageInfo(0);
1982   return GetOatAddressForOffset(primary_image_info.oat_address_offsets_[type], primary_image_info);
1983 }
1984
1985 const uint8_t* ImageWriter::GetQuickCode(ArtMethod* method,
1986                                          const ImageInfo& image_info,
1987                                          bool* quick_is_interpreted) {
1988   DCHECK(!method->IsResolutionMethod()) << PrettyMethod(method);
1989   DCHECK(!method->IsImtConflictMethod()) << PrettyMethod(method);
1990   DCHECK(!method->IsImtUnimplementedMethod()) << PrettyMethod(method);
1991   DCHECK(method->IsInvokable()) << PrettyMethod(method);
1992   DCHECK(!IsInBootImage(method)) << PrettyMethod(method);
1993
1994   // Use original code if it exists. Otherwise, set the code pointer to the resolution
1995   // trampoline.
1996
1997   // Quick entrypoint:
1998   const void* quick_oat_entry_point =
1999       method->GetEntryPointFromQuickCompiledCodePtrSize(target_ptr_size_);
2000   const uint8_t* quick_code;
2001
2002   if (UNLIKELY(IsInBootImage(method->GetDeclaringClass()))) {
2003     DCHECK(method->IsCopied());
2004     // If the code is not in the oat file corresponding to this image (e.g. default methods)
2005     quick_code = reinterpret_cast<const uint8_t*>(quick_oat_entry_point);
2006   } else {
2007     uint32_t quick_oat_code_offset = PointerToLowMemUInt32(quick_oat_entry_point);
2008     quick_code = GetOatAddressForOffset(quick_oat_code_offset, image_info);
2009   }
2010
2011   *quick_is_interpreted = false;
2012   if (quick_code != nullptr && (!method->IsStatic() || method->IsConstructor() ||
2013       method->GetDeclaringClass()->IsInitialized())) {
2014     // We have code for a non-static or initialized method, just use the code.
2015   } else if (quick_code == nullptr && method->IsNative() &&
2016       (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) {
2017     // Non-static or initialized native method missing compiled code, use generic JNI version.
2018     quick_code = GetOatAddress(kOatAddressQuickGenericJNITrampoline);
2019   } else if (quick_code == nullptr && !method->IsNative()) {
2020     // We don't have code at all for a non-native method, use the interpreter.
2021     quick_code = GetOatAddress(kOatAddressQuickToInterpreterBridge);
2022     *quick_is_interpreted = true;
2023   } else {
2024     CHECK(!method->GetDeclaringClass()->IsInitialized());
2025     // We have code for a static method, but need to go through the resolution stub for class
2026     // initialization.
2027     quick_code = GetOatAddress(kOatAddressQuickResolutionTrampoline);
2028   }
2029   if (!IsInBootOatFile(quick_code)) {
2030     // DCHECK_GE(quick_code, oat_data_begin_);
2031   }
2032   return quick_code;
2033 }
2034
2035 void ImageWriter::CopyAndFixupMethod(ArtMethod* orig,
2036                                      ArtMethod* copy,
2037                                      const ImageInfo& image_info) {
2038   memcpy(copy, orig, ArtMethod::Size(target_ptr_size_));
2039
2040   copy->SetDeclaringClass(GetImageAddress(orig->GetDeclaringClassUnchecked()));
2041   ArtMethod** orig_resolved_methods = orig->GetDexCacheResolvedMethods(target_ptr_size_);
2042   copy->SetDexCacheResolvedMethods(NativeLocationInImage(orig_resolved_methods), target_ptr_size_);
2043   GcRoot<mirror::Class>* orig_resolved_types = orig->GetDexCacheResolvedTypes(target_ptr_size_);
2044   copy->SetDexCacheResolvedTypes(NativeLocationInImage(orig_resolved_types), target_ptr_size_);
2045
2046   // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
2047   // oat_begin_
2048
2049   // The resolution method has a special trampoline to call.
2050   Runtime* runtime = Runtime::Current();
2051   if (UNLIKELY(orig == runtime->GetResolutionMethod())) {
2052     copy->SetEntryPointFromQuickCompiledCodePtrSize(
2053         GetOatAddress(kOatAddressQuickResolutionTrampoline), target_ptr_size_);
2054   } else if (UNLIKELY(orig == runtime->GetImtConflictMethod() ||
2055                       orig == runtime->GetImtUnimplementedMethod())) {
2056     copy->SetEntryPointFromQuickCompiledCodePtrSize(
2057         GetOatAddress(kOatAddressQuickIMTConflictTrampoline), target_ptr_size_);
2058   } else if (UNLIKELY(orig->IsRuntimeMethod())) {
2059     bool found_one = false;
2060     for (size_t i = 0; i < static_cast<size_t>(Runtime::kLastCalleeSaveType); ++i) {
2061       auto idx = static_cast<Runtime::CalleeSaveType>(i);
2062       if (runtime->HasCalleeSaveMethod(idx) && runtime->GetCalleeSaveMethod(idx) == orig) {
2063         found_one = true;
2064         break;
2065       }
2066     }
2067     CHECK(found_one) << "Expected to find callee save method but got " << PrettyMethod(orig);
2068     CHECK(copy->IsRuntimeMethod());
2069   } else {
2070     // We assume all methods have code. If they don't currently then we set them to the use the
2071     // resolution trampoline. Abstract methods never have code and so we need to make sure their
2072     // use results in an AbstractMethodError. We use the interpreter to achieve this.
2073     if (UNLIKELY(!orig->IsInvokable())) {
2074       copy->SetEntryPointFromQuickCompiledCodePtrSize(
2075           GetOatAddress(kOatAddressQuickToInterpreterBridge), target_ptr_size_);
2076     } else {
2077       bool quick_is_interpreted;
2078       const uint8_t* quick_code = GetQuickCode(orig, image_info, &quick_is_interpreted);
2079       copy->SetEntryPointFromQuickCompiledCodePtrSize(quick_code, target_ptr_size_);
2080
2081       // JNI entrypoint:
2082       if (orig->IsNative()) {
2083         // The native method's pointer is set to a stub to lookup via dlsym.
2084         // Note this is not the code_ pointer, that is handled above.
2085         copy->SetEntryPointFromJniPtrSize(
2086             GetOatAddress(kOatAddressJNIDlsymLookup), target_ptr_size_);
2087       }
2088     }
2089   }
2090 }
2091
2092 size_t ImageWriter::GetBinSizeSum(ImageWriter::ImageInfo& image_info, ImageWriter::Bin up_to) const {
2093   DCHECK_LE(up_to, kBinSize);
2094   return std::accumulate(&image_info.bin_slot_sizes_[0],
2095                          &image_info.bin_slot_sizes_[up_to],
2096                          /*init*/0);
2097 }
2098
2099 ImageWriter::BinSlot::BinSlot(uint32_t lockword) : lockword_(lockword) {
2100   // These values may need to get updated if more bins are added to the enum Bin
2101   static_assert(kBinBits == 3, "wrong number of bin bits");
2102   static_assert(kBinShift == 27, "wrong number of shift");
2103   static_assert(sizeof(BinSlot) == sizeof(LockWord), "BinSlot/LockWord must have equal sizes");
2104
2105   DCHECK_LT(GetBin(), kBinSize);
2106   DCHECK_ALIGNED(GetIndex(), kObjectAlignment);
2107 }
2108
2109 ImageWriter::BinSlot::BinSlot(Bin bin, uint32_t index)
2110     : BinSlot(index | (static_cast<uint32_t>(bin) << kBinShift)) {
2111   DCHECK_EQ(index, GetIndex());
2112 }
2113
2114 ImageWriter::Bin ImageWriter::BinSlot::GetBin() const {
2115   return static_cast<Bin>((lockword_ & kBinMask) >> kBinShift);
2116 }
2117
2118 uint32_t ImageWriter::BinSlot::GetIndex() const {
2119   return lockword_ & ~kBinMask;
2120 }
2121
2122 ImageWriter::Bin ImageWriter::BinTypeForNativeRelocationType(NativeObjectRelocationType type) {
2123   switch (type) {
2124     case kNativeObjectRelocationTypeArtField:
2125     case kNativeObjectRelocationTypeArtFieldArray:
2126       return kBinArtField;
2127     case kNativeObjectRelocationTypeArtMethodClean:
2128     case kNativeObjectRelocationTypeArtMethodArrayClean:
2129       return kBinArtMethodClean;
2130     case kNativeObjectRelocationTypeArtMethodDirty:
2131     case kNativeObjectRelocationTypeArtMethodArrayDirty:
2132       return kBinArtMethodDirty;
2133     case kNativeObjectRelocationTypeDexCacheArray:
2134       return kBinDexCacheArray;
2135   }
2136   UNREACHABLE();
2137 }
2138
2139 size_t ImageWriter::GetOatIndex(mirror::Object* obj) const {
2140   if (compile_app_image_) {
2141     return GetDefaultOatIndex();
2142   } else {
2143     mirror::DexCache* dex_cache =
2144         obj->IsDexCache() ? obj->AsDexCache()
2145                           : obj->IsClass() ? obj->AsClass()->GetDexCache()
2146                                            : obj->GetClass()->GetDexCache();
2147     return GetOatIndexForDexCache(dex_cache);
2148   }
2149 }
2150
2151 size_t ImageWriter::GetOatIndexForDexFile(const DexFile* dex_file) const {
2152   if (compile_app_image_) {
2153     return GetDefaultOatIndex();
2154   } else {
2155     auto it = dex_file_oat_index_map_.find(dex_file);
2156     DCHECK(it != dex_file_oat_index_map_.end()) << dex_file->GetLocation();
2157     return it->second;
2158   }
2159 }
2160
2161 size_t ImageWriter::GetOatIndexForDexCache(mirror::DexCache* dex_cache) const {
2162   if (dex_cache == nullptr) {
2163     return GetDefaultOatIndex();
2164   } else {
2165     return GetOatIndexForDexFile(dex_cache->GetDexFile());
2166   }
2167 }
2168
2169 void ImageWriter::UpdateOatFileLayout(size_t oat_index,
2170                                       size_t oat_loaded_size,
2171                                       size_t oat_data_offset,
2172                                       size_t oat_data_size) {
2173   const uint8_t* images_end = image_infos_.back().image_begin_ + image_infos_.back().image_size_;
2174   for (const ImageInfo& info : image_infos_) {
2175     DCHECK_LE(info.image_begin_ + info.image_size_, images_end);
2176   }
2177   DCHECK(images_end != nullptr);  // Image space must be ready.
2178
2179   ImageInfo& cur_image_info = GetImageInfo(oat_index);
2180   cur_image_info.oat_file_begin_ = images_end + cur_image_info.oat_offset_;
2181   cur_image_info.oat_loaded_size_ = oat_loaded_size;
2182   cur_image_info.oat_data_begin_ = cur_image_info.oat_file_begin_ + oat_data_offset;
2183   cur_image_info.oat_size_ = oat_data_size;
2184
2185   if (compile_app_image_) {
2186     CHECK_EQ(oat_filenames_.size(), 1u) << "App image should have no next image.";
2187     return;
2188   }
2189
2190   // Update the oat_offset of the next image info.
2191   if (oat_index + 1u != oat_filenames_.size()) {
2192     // There is a following one.
2193     ImageInfo& next_image_info = GetImageInfo(oat_index + 1u);
2194     next_image_info.oat_offset_ = cur_image_info.oat_offset_ + oat_loaded_size;
2195   }
2196 }
2197
2198 void ImageWriter::UpdateOatFileHeader(size_t oat_index, const OatHeader& oat_header) {
2199   ImageInfo& cur_image_info = GetImageInfo(oat_index);
2200   cur_image_info.oat_checksum_ = oat_header.GetChecksum();
2201
2202   if (oat_index == GetDefaultOatIndex()) {
2203     // Primary oat file, read the trampolines.
2204     cur_image_info.oat_address_offsets_[kOatAddressInterpreterToInterpreterBridge] =
2205         oat_header.GetInterpreterToInterpreterBridgeOffset();
2206     cur_image_info.oat_address_offsets_[kOatAddressInterpreterToCompiledCodeBridge] =
2207         oat_header.GetInterpreterToCompiledCodeBridgeOffset();
2208     cur_image_info.oat_address_offsets_[kOatAddressJNIDlsymLookup] =
2209         oat_header.GetJniDlsymLookupOffset();
2210     cur_image_info.oat_address_offsets_[kOatAddressQuickGenericJNITrampoline] =
2211         oat_header.GetQuickGenericJniTrampolineOffset();
2212     cur_image_info.oat_address_offsets_[kOatAddressQuickIMTConflictTrampoline] =
2213         oat_header.GetQuickImtConflictTrampolineOffset();
2214     cur_image_info.oat_address_offsets_[kOatAddressQuickResolutionTrampoline] =
2215         oat_header.GetQuickResolutionTrampolineOffset();
2216     cur_image_info.oat_address_offsets_[kOatAddressQuickToInterpreterBridge] =
2217         oat_header.GetQuickToInterpreterBridgeOffset();
2218   }
2219 }
2220
2221 ImageWriter::ImageWriter(
2222     const CompilerDriver& compiler_driver,
2223     uintptr_t image_begin,
2224     bool compile_pic,
2225     bool compile_app_image,
2226     ImageHeader::StorageMode image_storage_mode,
2227     const std::vector<const char*>& oat_filenames,
2228     const std::unordered_map<const DexFile*, size_t>& dex_file_oat_index_map)
2229     : compiler_driver_(compiler_driver),
2230       global_image_begin_(reinterpret_cast<uint8_t*>(image_begin)),
2231       image_objects_offset_begin_(0),
2232       compile_pic_(compile_pic),
2233       compile_app_image_(compile_app_image),
2234       target_ptr_size_(InstructionSetPointerSize(compiler_driver_.GetInstructionSet())),
2235       image_infos_(oat_filenames.size()),
2236       image_method_array_(ImageHeader::kImageMethodsCount),
2237       dirty_methods_(0u),
2238       clean_methods_(0u),
2239       image_storage_mode_(image_storage_mode),
2240       oat_filenames_(oat_filenames),
2241       dex_file_oat_index_map_(dex_file_oat_index_map) {
2242   CHECK_NE(image_begin, 0U);
2243   std::fill_n(image_methods_, arraysize(image_methods_), nullptr);
2244   CHECK_EQ(compile_app_image, !Runtime::Current()->GetHeap()->GetBootImageSpaces().empty())
2245       << "Compiling a boot image should occur iff there are no boot image spaces loaded";
2246 }
2247
2248 ImageWriter::ImageInfo::ImageInfo()
2249     : intern_table_(new InternTable),
2250       class_table_(new ClassTable) {}
2251
2252 }  // namespace art