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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "image_writer.h"
#include <sys/mman.h>
#include <vector>
#include "UniquePtr.h"
#include "class_linker.h"
#include "class_loader.h"
#include "compiled_method.h"
#include "compiler.h"
#include "dex_cache.h"
#include "file.h"
#include "globals.h"
#include "heap.h"
#include "image.h"
#include "intern_table.h"
#include "logging.h"
#include "oat_file.h"
#include "object.h"
#include "object_utils.h"
#include "runtime.h"
#include "space.h"
#include "utils.h"
namespace art {
bool ImageWriter::Write(const std::string& image_filename,
uintptr_t image_begin,
const std::string& oat_filename,
const std::string& oat_location,
const Compiler& compiler) {
CHECK(!image_filename.empty());
CHECK_NE(image_begin, 0U);
image_begin_ = reinterpret_cast<byte*>(image_begin);
Heap* heap = Runtime::Current()->GetHeap();
source_space_ = heap->GetAllocSpace();
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
const std::vector<DexCache*>& all_dex_caches = class_linker->GetDexCaches();
for (size_t i = 0; i < all_dex_caches.size(); i++) {
DexCache* dex_cache = all_dex_caches[i];
if (InSourceSpace(dex_cache)) {
dex_caches_.insert(dex_cache);
}
}
oat_file_ = OatFile::Open(oat_filename, oat_location, NULL,
OatFile::kRelocNone, true);
if (oat_file_ == NULL) {
LOG(ERROR) << "Failed to open oat file " << oat_filename;
return false;
}
class_linker->RegisterOatFile(*oat_file_);
PruneNonImageClasses(); // Remove junk
ComputeLazyFieldsForImageClasses(); // Add useful information
ComputeEagerResolvedStrings();
heap->CollectGarbage(false); // Remove garbage
heap->GetAllocSpace()->Trim(); // Trim size of source_space
if (!AllocMemory()) {
return false;
}
#ifndef NDEBUG
CheckNonImageClassesRemoved();
#endif
heap->DisableCardMarking();
CalculateNewObjectOffsets();
CopyAndFixupObjects();
PatchOatCodeAndMethods(compiler);
UniquePtr<File> file(OS::OpenFile(image_filename.c_str(), true));
if (file.get() == NULL) {
LOG(ERROR) << "Failed to open image file " << image_filename;
return false;
}
bool success = file->WriteFully(image_->Begin(), image_end_);
if (!success) {
PLOG(ERROR) << "Failed to write image file " << image_filename;
return false;
}
return true;
}
bool ImageWriter::AllocMemory() {
size_t size = source_space_->Size();
int prot = PROT_READ | PROT_WRITE;
size_t length = RoundUp(size, kPageSize);
image_.reset(MemMap::MapAnonymous("image-writer-image", NULL, length, prot));
if (image_.get() == NULL) {
LOG(ERROR) << "Failed to allocate memory for image file generation";
return false;
}
return true;
}
void ImageWriter::ComputeLazyFieldsForImageClasses() {
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
class_linker->VisitClasses(ComputeLazyFieldsForClassesVisitor, NULL);
}
bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
c->ComputeName();
return true;
}
void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) {
if (!obj->GetClass()->IsStringClass()) {
return;
}
String* string = obj->AsString();
std::string utf8_string(string->ToModifiedUtf8());
ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
ClassLinker* linker = Runtime::Current()->GetClassLinker();
typedef Set::const_iterator CacheIt; // TODO: C++0x auto
for (CacheIt it = writer->dex_caches_.begin(), end = writer->dex_caches_.end(); it != end; ++it) {
DexCache* dex_cache = *it;
const DexFile& dex_file = linker->FindDexFile(dex_cache);
const DexFile::StringId* string_id = dex_file.FindStringId(utf8_string);
if (string_id != NULL) {
// This string occurs in this dex file, assign the dex cache entry.
uint32_t string_idx = dex_file.GetIndexForStringId(*string_id);
if (dex_cache->GetResolvedString(string_idx) == NULL) {
dex_cache->SetResolvedString(string_idx, string);
}
}
}
}
void ImageWriter::ComputeEagerResolvedStrings() {
HeapBitmap* heap_bitmap = Runtime::Current()->GetHeap()->GetLiveBits();
DCHECK(heap_bitmap != NULL);
heap_bitmap->Walk(ComputeEagerResolvedStringsCallback, this); // TODO: add Space-limited Walk
}
bool ImageWriter::IsImageClass(const Class* klass) {
if (image_classes_ == NULL) {
return true;
}
while (klass->IsArrayClass()) {
klass = klass->GetComponentType();
}
if (klass->IsPrimitive()) {
return true;
}
const std::string descriptor(ClassHelper(klass).GetDescriptor());
return image_classes_->find(descriptor) != image_classes_->end();
}
struct NonImageClasses {
ImageWriter* image_writer;
std::set<std::string>* non_image_classes;
};
void ImageWriter::PruneNonImageClasses() {
if (image_classes_ == NULL) {
return;
}
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
std::set<std::string> non_image_classes;
NonImageClasses context;
context.image_writer = this;
context.non_image_classes = &non_image_classes;
class_linker->VisitClasses(NonImageClassesVisitor, &context);
typedef std::set<std::string>::const_iterator ClassIt; // TODO: C++0x auto
for (ClassIt it = non_image_classes.begin(), end = non_image_classes.end(); it != end; ++it) {
class_linker->RemoveClass((*it).c_str(), NULL);
}
Method* resolution_method = runtime->GetResolutionMethod();
typedef Set::const_iterator CacheIt; // TODO: C++0x auto
for (CacheIt it = dex_caches_.begin(), end = dex_caches_.end(); it != end; ++it) {
DexCache* dex_cache = *it;
for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
Class* klass = dex_cache->GetResolvedType(i);
if (klass != NULL && !IsImageClass(klass)) {
dex_cache->SetResolvedType(i, NULL);
dex_cache->GetInitializedStaticStorage()->Set(i, NULL);
}
}
for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) {
Method* method = dex_cache->GetResolvedMethod(i);
if (method != NULL && !IsImageClass(method->GetDeclaringClass())) {
dex_cache->SetResolvedMethod(i, resolution_method);
}
}
for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
Field* field = dex_cache->GetResolvedField(i);
if (field != NULL && !IsImageClass(field->GetDeclaringClass())) {
dex_cache->SetResolvedField(i, NULL);
}
}
}
}
bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) {
NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg);
if (!context->image_writer->IsImageClass(klass)) {
context->non_image_classes->insert(ClassHelper(klass).GetDescriptor());
}
return true;
}
void ImageWriter::CheckNonImageClassesRemoved() {
if (image_classes_ == NULL) {
return;
}
Runtime::Current()->GetHeap()->GetLiveBits()->Walk(CheckNonImageClassesRemovedCallback, this);
}
void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
if (!obj->IsClass()) {
return;
}
Class* klass = obj->AsClass();
if (!image_writer->IsImageClass(klass)) {
image_writer->DumpImageClasses();
CHECK(image_writer->IsImageClass(klass)) << ClassHelper(klass).GetDescriptor()
<< " " << PrettyDescriptor(klass);
}
}
void ImageWriter::DumpImageClasses() {
typedef std::set<std::string>::const_iterator It; // TODO: C++0x auto
for (It it = image_classes_->begin(), end = image_classes_->end(); it != end; ++it) {
LOG(INFO) << " " << *it;
}
}
void ImageWriter::CalculateNewObjectOffsetsCallback(Object* obj, void* arg) {
DCHECK(obj != NULL);
DCHECK(arg != NULL);
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
if (!image_writer->InSourceSpace(obj)) {
return;
}
// if it is a string, we want to intern it if its not interned.
if (obj->GetClass()->IsStringClass()) {
// we must be an interned string that was forward referenced and already assigned
if (image_writer->IsImageOffsetAssigned(obj)) {
DCHECK_EQ(obj, obj->AsString()->Intern());
return;
}
SirtRef<String> interned(obj->AsString()->Intern());
if (obj != interned.get()) {
if (!image_writer->IsImageOffsetAssigned(interned.get())) {
// interned obj is after us, allocate its location early
image_writer->AssignImageOffset(interned.get());
}
// point those looking for this object to the interned version.
image_writer->SetImageOffset(obj, image_writer->GetImageOffset(interned.get()));
return;
}
// else (obj == interned), nothing to do but fall through to the normal case
}
image_writer->AssignImageOffset(obj);
}
ObjectArray<Object>* ImageWriter::CreateImageRoots() const {
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
Class* object_array_class = class_linker->FindSystemClass("[Ljava/lang/Object;");
// build an Object[] of all the DexCaches used in the source_space_
ObjectArray<Object>* dex_caches = ObjectArray<Object>::Alloc(object_array_class,
dex_caches_.size());
int i = 0;
typedef Set::const_iterator It; // TODO: C++0x auto
for (It it = dex_caches_.begin(), end = dex_caches_.end(); it != end; ++it, ++i) {
dex_caches->Set(i, *it);
}
// build an Object[] of the roots needed to restore the runtime
SirtRef<ObjectArray<Object> > image_roots(
ObjectArray<Object>::Alloc(object_array_class, ImageHeader::kImageRootsMax));
image_roots->Set(ImageHeader::kJniStubArray, runtime->GetJniDlsymLookupStub());
image_roots->Set(ImageHeader::kAbstractMethodErrorStubArray,
runtime->GetAbstractMethodErrorStubArray());
image_roots->Set(ImageHeader::kStaticResolutionStubArray,
runtime->GetResolutionStubArray(Runtime::kStaticMethod));
image_roots->Set(ImageHeader::kUnknownMethodResolutionStubArray,
runtime->GetResolutionStubArray(Runtime::kUnknownMethod));
image_roots->Set(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
image_roots->Set(ImageHeader::kCalleeSaveMethod,
runtime->GetCalleeSaveMethod(Runtime::kSaveAll));
image_roots->Set(ImageHeader::kRefsOnlySaveMethod,
runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
image_roots->Set(ImageHeader::kRefsAndArgsSaveMethod,
runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
image_roots->Set(ImageHeader::kOatLocation,
String::AllocFromModifiedUtf8(oat_file_->GetLocation().c_str()));
image_roots->Set(ImageHeader::kDexCaches,
dex_caches);
image_roots->Set(ImageHeader::kClassRoots,
class_linker->GetClassRoots());
for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
CHECK(image_roots->Get(i) != NULL);
}
return image_roots.get();
}
void ImageWriter::CalculateNewObjectOffsets() {
SirtRef<ObjectArray<Object> > image_roots(CreateImageRoots());
HeapBitmap* heap_bitmap = Runtime::Current()->GetHeap()->GetLiveBits();
DCHECK(heap_bitmap != NULL);
DCHECK_EQ(0U, image_end_);
// leave space for the header, but do not write it yet, we need to
// know where image_roots is going to end up
image_end_ += RoundUp(sizeof(ImageHeader), 8); // 64-bit-alignment
heap_bitmap->InOrderWalk(CalculateNewObjectOffsetsCallback, this); // TODO: add Space-limited Walk
DCHECK_LT(image_end_, image_->Size());
// Note that image_top_ is left at end of used space
oat_begin_ = image_begin_ + RoundUp(image_end_, kPageSize);
const byte* oat_limit = oat_begin_ + oat_file_->Size();
// return to write header at start of image with future location of image_roots
ImageHeader image_header(reinterpret_cast<uint32_t>(image_begin_),
reinterpret_cast<uint32_t>(GetImageAddress(image_roots.get())),
oat_file_->GetOatHeader().GetChecksum(),
reinterpret_cast<uint32_t>(oat_begin_),
reinterpret_cast<uint32_t>(oat_limit));
memcpy(image_->Begin(), &image_header, sizeof(image_header));
}
void ImageWriter::CopyAndFixupObjects() {
Heap* heap = Runtime::Current()->GetHeap();
HeapBitmap* heap_bitmap = heap->GetLiveBits();
DCHECK(heap_bitmap != NULL);
// TODO: heap validation can't handle this fix up pass
heap->DisableObjectValidation();
heap_bitmap->Walk(CopyAndFixupObjectsCallback, this); // TODO: add Space-limited Walk
}
void ImageWriter::CopyAndFixupObjectsCallback(Object* object, void* arg) {
DCHECK(object != NULL);
DCHECK(arg != NULL);
const Object* obj = object;
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
if (!image_writer->InSourceSpace(object)) {
return;
}
// see GetLocalAddress for similar computation
size_t offset = image_writer->GetImageOffset(obj);
byte* dst = image_writer->image_->Begin() + offset;
const byte* src = reinterpret_cast<const byte*>(obj);
size_t n = obj->SizeOf();
DCHECK_LT(offset + n, image_writer->image_->Size());
memcpy(dst, src, n);
Object* copy = reinterpret_cast<Object*>(dst);
copy->monitor_ = 0; // We may have inflated the lock during compilation.
image_writer->FixupObject(obj, copy);
}
void ImageWriter::FixupObject(const Object* orig, Object* copy) {
DCHECK(orig != NULL);
DCHECK(copy != NULL);
copy->SetClass(down_cast<Class*>(GetImageAddress(orig->GetClass())));
// TODO: special case init of pointers to malloc data (or removal of these pointers)
if (orig->IsClass()) {
FixupClass(orig->AsClass(), down_cast<Class*>(copy));
} else if (orig->IsObjectArray()) {
FixupObjectArray(orig->AsObjectArray<Object>(), down_cast<ObjectArray<Object>*>(copy));
} else if (orig->IsMethod()) {
FixupMethod(orig->AsMethod(), down_cast<Method*>(copy));
} else {
FixupInstanceFields(orig, copy);
}
}
void ImageWriter::FixupClass(const Class* orig, Class* copy) {
FixupInstanceFields(orig, copy);
FixupStaticFields(orig, copy);
}
void ImageWriter::FixupMethod(const Method* orig, Method* copy) {
FixupInstanceFields(orig, copy);
// OatWriter replaces the code_ and invoke_stub_ with offset values.
// Here we readjust to a pointer relative to oat_begin_
// Every type of method can have an invoke stub
uint32_t invoke_stub_offset = orig->GetOatInvokeStubOffset();
const byte* invoke_stub = GetOatAddress(invoke_stub_offset);
copy->invoke_stub_ = reinterpret_cast<const Method::InvokeStub*>(invoke_stub);
if (orig->IsAbstract()) {
// Abstract methods are pointed to a stub that will throw AbstractMethodError if they are called
ByteArray* orig_ame_stub_array_ = Runtime::Current()->GetAbstractMethodErrorStubArray();
ByteArray* copy_ame_stub_array_ = down_cast<ByteArray*>(GetImageAddress(orig_ame_stub_array_));
copy->code_ = copy_ame_stub_array_->GetData();
return;
}
if (orig == Runtime::Current()->GetResolutionMethod()) {
// The resolution stub's code points at the unknown resolution trampoline
ByteArray* orig_res_stub_array_ =
Runtime::Current()->GetResolutionStubArray(Runtime::kUnknownMethod);
CHECK(orig->GetCode() == orig_res_stub_array_->GetData());
ByteArray* copy_res_stub_array_ = down_cast<ByteArray*>(GetImageAddress(orig_res_stub_array_));
copy->code_ = copy_res_stub_array_->GetData();
return;
}
// Non-abstract methods typically have code
uint32_t code_offset = orig->GetOatCodeOffset();
const byte* code = NULL;
if (orig->IsStatic()) {
// Static methods may point at the resolution trampoline stub
ByteArray* orig_res_stub_array_ =
Runtime::Current()->GetResolutionStubArray(Runtime::kStaticMethod);
if (reinterpret_cast<int8_t*>(code_offset) == orig_res_stub_array_->GetData()) {
ByteArray* copy_res_stub_array_ = down_cast<ByteArray*>(GetImageAddress(orig_res_stub_array_));
code = reinterpret_cast<const byte*>(copy_res_stub_array_->GetData());
}
}
if (code == NULL) {
code = GetOatAddress(code_offset);
}
copy->code_ = code;
if (orig->IsNative()) {
// The native method's pointer is directed to a stub to lookup via dlsym.
// Note this is not the code_ pointer, that is handled above.
ByteArray* orig_jni_stub_array_ = Runtime::Current()->GetJniDlsymLookupStub();
ByteArray* copy_jni_stub_array_ = down_cast<ByteArray*>(GetImageAddress(orig_jni_stub_array_));
copy->native_method_ = copy_jni_stub_array_->GetData();
} else {
// normal (non-abstract non-native) methods have mapping tables to relocate
uint32_t mapping_table_off = orig->GetOatMappingTableOffset();
const byte* mapping_table = GetOatAddress(mapping_table_off);
copy->mapping_table_ = reinterpret_cast<const uint32_t*>(mapping_table);
uint32_t vmap_table_offset = orig->GetOatVmapTableOffset();
const byte* vmap_table = GetOatAddress(vmap_table_offset);
copy->vmap_table_ = reinterpret_cast<const uint16_t*>(vmap_table);
uint32_t gc_map_offset = orig->GetOatGcMapOffset();
const byte* gc_map = GetOatAddress(gc_map_offset);
copy->gc_map_ = reinterpret_cast<const uint8_t*>(gc_map);
}
}
void ImageWriter::FixupObjectArray(const ObjectArray<Object>* orig, ObjectArray<Object>* copy) {
for (int32_t i = 0; i < orig->GetLength(); ++i) {
const Object* element = orig->Get(i);
copy->SetWithoutChecks(i, GetImageAddress(element));
}
}
void ImageWriter::FixupInstanceFields(const Object* orig, Object* copy) {
DCHECK(orig != NULL);
DCHECK(copy != NULL);
Class* klass = orig->GetClass();
DCHECK(klass != NULL);
FixupFields(orig,
copy,
klass->GetReferenceInstanceOffsets(),
false);
}
void ImageWriter::FixupStaticFields(const Class* orig, Class* copy) {
DCHECK(orig != NULL);
DCHECK(copy != NULL);
FixupFields(orig,
copy,
orig->GetReferenceStaticOffsets(),
true);
}
void ImageWriter::FixupFields(const Object* orig,
Object* copy,
uint32_t ref_offsets,
bool is_static) {
if (ref_offsets != CLASS_WALK_SUPER) {
// Found a reference offset bitmap. Fixup the specified offsets.
while (ref_offsets != 0) {
size_t right_shift = CLZ(ref_offsets);
MemberOffset byte_offset = CLASS_OFFSET_FROM_CLZ(right_shift);
const Object* ref = orig->GetFieldObject<const Object*>(byte_offset, false);
copy->SetFieldObject(byte_offset, GetImageAddress(ref), false);
ref_offsets &= ~(CLASS_HIGH_BIT >> right_shift);
}
} else {
// There is no reference offset bitmap. In the non-static case,
// walk up the class inheritance hierarchy and find reference
// offsets the hard way. In the static case, just consider this
// class.
for (const Class *klass = is_static ? orig->AsClass() : orig->GetClass();
klass != NULL;
klass = is_static ? NULL : klass->GetSuperClass()) {
size_t num_reference_fields = (is_static
? klass->NumReferenceStaticFields()
: klass->NumReferenceInstanceFields());
for (size_t i = 0; i < num_reference_fields; ++i) {
Field* field = (is_static
? klass->GetStaticField(i)
: klass->GetInstanceField(i));
MemberOffset field_offset = field->GetOffset();
const Object* ref = orig->GetFieldObject<const Object*>(field_offset, false);
copy->SetFieldObject(field_offset, GetImageAddress(ref), false);
}
}
}
}
static Method* GetReferrerMethod(const Compiler::PatchInformation* patch) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
Method* method = class_linker->ResolveMethod(patch->GetDexFile(),
patch->GetReferrerMethodIdx(),
patch->GetDexCache(),
NULL,
patch->GetReferrerIsDirect());
CHECK(method != NULL)
<< patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx();
CHECK(!method->IsRuntimeMethod())
<< patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx();
CHECK(patch->GetDexCache()->GetResolvedMethods()->Get(patch->GetReferrerMethodIdx()) == method)
<< patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
<< PrettyMethod(patch->GetDexCache()->GetResolvedMethods()->Get(patch->GetReferrerMethodIdx())) << " "
<< PrettyMethod(method);
return method;
}
static Method* GetTargetMethod(const Compiler::PatchInformation* patch) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
Method* method = class_linker->ResolveMethod(patch->GetDexFile(),
patch->GetTargetMethodIdx(),
patch->GetDexCache(),
NULL,
patch->GetTargetIsDirect());
CHECK(method != NULL)
<< patch->GetDexFile().GetLocation() << " " << patch->GetTargetMethodIdx();
CHECK(!method->IsRuntimeMethod())
<< patch->GetDexFile().GetLocation() << " " << patch->GetTargetMethodIdx();
CHECK(patch->GetDexCache()->GetResolvedMethods()->Get(patch->GetTargetMethodIdx()) == method)
<< patch->GetDexFile().GetLocation() << " " << patch->GetReferrerMethodIdx() << " "
<< PrettyMethod(patch->GetDexCache()->GetResolvedMethods()->Get(patch->GetTargetMethodIdx())) << " "
<< PrettyMethod(method);
return method;
}
void ImageWriter::PatchOatCodeAndMethods(const Compiler& compiler) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
const std::vector<const Compiler::PatchInformation*>& code_to_patch = compiler.GetCodeToPatch();
for (size_t i = 0; i < code_to_patch.size(); i++) {
const Compiler::PatchInformation* patch = code_to_patch[i];
Method* target = GetTargetMethod(patch);
uint32_t code = reinterpret_cast<uint32_t>(class_linker->GetOatCodeFor(target));
uint32_t code_base = reinterpret_cast<uint32_t>(&oat_file_->GetOatHeader());
uint32_t code_offset = code - code_base;
SetPatchLocation(patch, reinterpret_cast<uint32_t>(GetOatAddress(code_offset)));
}
const std::vector<const Compiler::PatchInformation*>& methods_to_patch
= compiler.GetMethodsToPatch();
for (size_t i = 0; i < methods_to_patch.size(); i++) {
const Compiler::PatchInformation* patch = methods_to_patch[i];
Method* target = GetTargetMethod(patch);
SetPatchLocation(patch, reinterpret_cast<uint32_t>(GetImageAddress(target)));
}
}
void ImageWriter::SetPatchLocation(const Compiler::PatchInformation* patch, uint32_t value) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
Method* method = GetReferrerMethod(patch);
// Goodbye const, we are about to modify some code.
void* code = const_cast<void*>(class_linker->GetOatCodeFor(method));
// TODO: make this Thumb2 specific
uint8_t* base = reinterpret_cast<uint8_t*>(reinterpret_cast<uint32_t>(code) & ~0x1);
uint32_t* patch_location = reinterpret_cast<uint32_t*>(base + patch->GetLiteralOffset());
#ifndef NDEBUG
const DexFile::MethodId& id = patch->GetDexFile().GetMethodId(patch->GetTargetMethodIdx());
uint32_t expected = reinterpret_cast<uint32_t>(&id);
uint32_t actual = *patch_location;
CHECK(actual == expected || actual == value) << std::hex
<< "actual=" << actual
<< "expected=" << expected
<< "value=" << value;
#endif
*patch_location = value;
}
} // namespace art