runtime/aot_class_linker.cc - platform/art - Git at Google

 /*
  * Copyright (C) 2017 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 "aot_class_linker.h"

 #include "class_status.h"
 #include "compiler_callbacks.h"
 #include "dex/class_reference.h"
 #include "gc/heap.h"
 #include "handle_scope-inl.h"
 #include "mirror/class-inl.h"
 #include "runtime.h"
 #include "verifier/verifier_enums.h"

 namespace art {

 AotClassLinker::AotClassLinker(InternTable* intern_table)
     : ClassLinker(intern_table, /*fast_class_not_found_exceptions=*/ false) {}

 AotClassLinker::~AotClassLinker() {}

 bool AotClassLinker::CanAllocClass() {
   // AllocClass doesn't work under transaction, so we abort.
   if (Runtime::Current()->IsActiveTransaction()) {
     Runtime::Current()->AbortTransactionAndThrowAbortError(
         Thread::Current(), "Can't resolve type within transaction.");
     return false;
   }
   return ClassLinker::CanAllocClass();
 }

 // Wrap the original InitializeClass with creation of transaction when in strict mode.
 bool AotClassLinker::InitializeClass(Thread* self,
                                      Handle<mirror::Class> klass,
                                      bool can_init_statics,
                                      bool can_init_parents) {
   Runtime* const runtime = Runtime::Current();
   bool strict_mode = runtime->IsActiveStrictTransactionMode();

   DCHECK(klass != nullptr);
   if (klass->IsInitialized() || klass->IsInitializing()) {
     return ClassLinker::InitializeClass(self, klass, can_init_statics, can_init_parents);
   }

   // When compiling a boot image extension, do not initialize a class defined
   // in a dex file belonging to the boot image we're compiling against.
   // However, we must allow the initialization of TransactionAbortError,
   // VerifyError, etc. outside of a transaction.
   if (!strict_mode && runtime->GetHeap()->ObjectIsInBootImageSpace(klass->GetDexCache())) {
     if (runtime->IsActiveTransaction()) {
       runtime->AbortTransactionAndThrowAbortError(self, "Can't initialize " + klass->PrettyTypeOf()
            + " because it is defined in a boot image dex file.");
       return false;
     }
     CHECK(klass->IsThrowableClass()) << klass->PrettyDescriptor();
   }

   // When in strict_mode, don't initialize a class if it belongs to boot but not initialized.
   if (strict_mode && klass->IsBootStrapClassLoaded()) {
     runtime->AbortTransactionAndThrowAbortError(self, "Can't resolve "
         + klass->PrettyTypeOf() + " because it is an uninitialized boot class.");
     return false;
   }

   // Don't initialize klass if it's superclass is not initialized, because superclass might abort
   // the transaction and rolled back after klass's change is commited.
   if (strict_mode && !klass->IsInterface() && klass->HasSuperClass()) {
     if (klass->GetSuperClass()->GetStatus() == ClassStatus::kInitializing) {
       runtime->AbortTransactionAndThrowAbortError(self, "Can't resolve "
           + klass->PrettyTypeOf() + " because it's superclass is not initialized.");
       return false;
     }
   }

   if (strict_mode) {
     runtime->EnterTransactionMode(/*strict=*/ true, klass.Get());
   }
   bool success = ClassLinker::InitializeClass(self, klass, can_init_statics, can_init_parents);

   if (strict_mode) {
     if (success) {
       // Exit Transaction if success.
       runtime->ExitTransactionMode();
     } else {
       // If not successfully initialized, don't rollback immediately, leave the cleanup to compiler
       // driver which needs abort message and exception.
       DCHECK(self->IsExceptionPending());
     }
   }
   return success;
 }

 verifier::FailureKind AotClassLinker::PerformClassVerification(Thread* self,
                                                                Handle<mirror::Class> klass,
                                                                verifier::HardFailLogMode log_level,
                                                                std::string* error_msg) {
   Runtime* const runtime = Runtime::Current();
   CompilerCallbacks* callbacks = runtime->GetCompilerCallbacks();
   ClassStatus old_status = callbacks->GetPreviousClassState(
       ClassReference(&klass->GetDexFile(), klass->GetDexClassDefIndex()));
   // Was it verified? Report no failure.
   if (old_status >= ClassStatus::kVerified) {
     return verifier::FailureKind::kNoFailure;
   }
   if (old_status >= ClassStatus::kVerifiedNeedsAccessChecks) {
     return verifier::FailureKind::kAccessChecksFailure;
   }
   // Does it need to be verified at runtime? Report soft failure.
   if (old_status >= ClassStatus::kRetryVerificationAtRuntime) {
     // Error messages from here are only reported through -verbose:class. It is not worth it to
     // create a message.
     return verifier::FailureKind::kSoftFailure;
   }
   // Do the actual work.
   return ClassLinker::PerformClassVerification(self, klass, log_level, error_msg);
 }

 bool AotClassLinker::CanReferenceInBootImageExtension(ObjPtr<mirror::Class> klass, gc::Heap* heap) {
   // Do not allow referencing a class or instance of a class defined in a dex file
   // belonging to the boot image we're compiling against but not itself in the boot image;
   // or a class referencing such classes as component type, superclass or interface.
   // Allowing this could yield duplicate class objects from multiple extensions.

   if (heap->ObjectIsInBootImageSpace(klass)) {
     return true;  // Already included in the boot image we're compiling against.
   }

   // Treat arrays and primitive types specially because they do not have a DexCache that we
   // can use to check whether the dex file belongs to the boot image we're compiling against.
   DCHECK(!klass->IsPrimitive());  // Primitive classes must be in the primary boot image.
   if (klass->IsArrayClass()) {
     DCHECK(heap->ObjectIsInBootImageSpace(klass->GetIfTable()));  // IfTable is OK.
     // Arrays of all dimensions are tied to the dex file of the non-array component type.
     do {
       klass = klass->GetComponentType();
     } while (klass->IsArrayClass());
     if (klass->IsPrimitive()) {
       return false;
     }
     // Do not allow arrays of erroneous classes (the array class is not itself erroneous).
     if (klass->IsErroneous()) {
       return false;
     }
   }

   // Check the class itself.
   if (heap->ObjectIsInBootImageSpace(klass->GetDexCache())) {
     return false;
   }

   // Check superclasses.
   ObjPtr<mirror::Class> superclass = klass->GetSuperClass();
   while (!heap->ObjectIsInBootImageSpace(superclass)) {
     DCHECK(superclass != nullptr);  // Cannot skip Object which is in the primary boot image.
     if (heap->ObjectIsInBootImageSpace(superclass->GetDexCache())) {
       return false;
     }
     superclass = superclass->GetSuperClass();
   }

   // Check IfTable. This includes direct and indirect interfaces.
   ObjPtr<mirror::IfTable> if_table = klass->GetIfTable();
   for (size_t i = 0, num_interfaces = klass->GetIfTableCount(); i < num_interfaces; ++i) {
     ObjPtr<mirror::Class> interface = if_table->GetInterface(i);
     DCHECK(interface != nullptr);
     if (!heap->ObjectIsInBootImageSpace(interface) &&
         heap->ObjectIsInBootImageSpace(interface->GetDexCache())) {
       return false;
     }
   }

   if (kIsDebugBuild) {
     // All virtual methods must come from classes we have already checked above.
     PointerSize pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
     ObjPtr<mirror::Class> k = klass;
     while (!heap->ObjectIsInBootImageSpace(k)) {
       for (auto& m : k->GetVirtualMethods(pointer_size)) {
         ObjPtr<mirror::Class> declaring_class = m.GetDeclaringClass();
         CHECK(heap->ObjectIsInBootImageSpace(declaring_class) ||
               !heap->ObjectIsInBootImageSpace(declaring_class->GetDexCache()));
       }
       k = k->GetSuperClass();
     }
   }

   return true;
 }

 bool AotClassLinker::SetUpdatableBootClassPackages(const std::vector<std::string>& packages) {
   DCHECK(updatable_boot_class_path_descriptor_prefixes_.empty());
   // Transform package names to descriptor prefixes.
   std::vector<std::string> prefixes;
   prefixes.reserve(packages.size());
   for (const std::string& package : packages) {
     if (package.empty() || package.find('/') != std::string::npos) {
       LOG(ERROR) << "Invalid package name: " << package;
       return false;
     }
     std::string prefix = 'L' + package + '/';
     std::replace(prefix.begin(), prefix.end(), '.', '/');
     prefixes.push_back(std::move(prefix));
   }
   // Sort and remove unnecessary prefixes.
   std::sort(prefixes.begin(), prefixes.end());
   std::string last_prefix;
   auto end_it = std::remove_if(
       prefixes.begin(),
       prefixes.end(),
       [&last_prefix](const std::string& s) {
         if (!last_prefix.empty() && StartsWith(s, last_prefix)) {
           return true;
         } else {
           last_prefix = s;
           return false;
         }
       });
   prefixes.resize(std::distance(prefixes.begin(), end_it));
   prefixes.shrink_to_fit();
   updatable_boot_class_path_descriptor_prefixes_.swap(prefixes);
   return true;
 }

 bool AotClassLinker::IsUpdatableBootClassPathDescriptor(const char* descriptor) {
   std::string_view descriptor_sv(descriptor);
   for (const std::string& prefix : updatable_boot_class_path_descriptor_prefixes_) {
     if (StartsWith(descriptor_sv, prefix)) {
       return true;
     }
   }
   return false;
 }

 }  // namespace art
	/*
	* Copyright (C) 2017 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 "aot_class_linker.h"

	#include "class_status.h"
	#include "compiler_callbacks.h"
	#include "dex/class_reference.h"
	#include "gc/heap.h"
	#include "handle_scope-inl.h"
	#include "mirror/class-inl.h"
	#include "runtime.h"
	#include "verifier/verifier_enums.h"

	namespace art {

	AotClassLinker::AotClassLinker(InternTable* intern_table)
	: ClassLinker(intern_table, /fast_class_not_found_exceptions=/ false) {}

	AotClassLinker::~AotClassLinker() {}

	bool AotClassLinker::CanAllocClass() {
	// AllocClass doesn't work under transaction, so we abort.
	if (Runtime::Current()->IsActiveTransaction()) {
	Runtime::Current()->AbortTransactionAndThrowAbortError(
	Thread::Current(), "Can't resolve type within transaction.");
	return false;
	}
	return ClassLinker::CanAllocClass();
	}

	// Wrap the original InitializeClass with creation of transaction when in strict mode.
	bool AotClassLinker::InitializeClass(Thread* self,
	Handle<mirror::Class> klass,
	bool can_init_statics,
	bool can_init_parents) {
	Runtime* const runtime = Runtime::Current();
	bool strict_mode = runtime->IsActiveStrictTransactionMode();

	DCHECK(klass != nullptr);
	if (klass->IsInitialized() \|\| klass->IsInitializing()) {
	return ClassLinker::InitializeClass(self, klass, can_init_statics, can_init_parents);
	}

	// When compiling a boot image extension, do not initialize a class defined
	// in a dex file belonging to the boot image we're compiling against.
	// However, we must allow the initialization of TransactionAbortError,
	// VerifyError, etc. outside of a transaction.
	if (!strict_mode && runtime->GetHeap()->ObjectIsInBootImageSpace(klass->GetDexCache())) {
	if (runtime->IsActiveTransaction()) {
	runtime->AbortTransactionAndThrowAbortError(self, "Can't initialize " + klass->PrettyTypeOf()
	+ " because it is defined in a boot image dex file.");
	return false;
	}
	CHECK(klass->IsThrowableClass()) << klass->PrettyDescriptor();
	}

	// When in strict_mode, don't initialize a class if it belongs to boot but not initialized.
	if (strict_mode && klass->IsBootStrapClassLoaded()) {
	runtime->AbortTransactionAndThrowAbortError(self, "Can't resolve "
	+ klass->PrettyTypeOf() + " because it is an uninitialized boot class.");
	return false;
	}

	// Don't initialize klass if it's superclass is not initialized, because superclass might abort
	// the transaction and rolled back after klass's change is commited.
	if (strict_mode && !klass->IsInterface() && klass->HasSuperClass()) {
	if (klass->GetSuperClass()->GetStatus() == ClassStatus::kInitializing) {
	runtime->AbortTransactionAndThrowAbortError(self, "Can't resolve "
	+ klass->PrettyTypeOf() + " because it's superclass is not initialized.");
	return false;
	}
	}

	if (strict_mode) {
	runtime->EnterTransactionMode(/strict=/ true, klass.Get());
	}
	bool success = ClassLinker::InitializeClass(self, klass, can_init_statics, can_init_parents);

	if (strict_mode) {
	if (success) {
	// Exit Transaction if success.
	runtime->ExitTransactionMode();
	} else {
	// If not successfully initialized, don't rollback immediately, leave the cleanup to compiler
	// driver which needs abort message and exception.
	DCHECK(self->IsExceptionPending());
	}
	}
	return success;
	}

	verifier::FailureKind AotClassLinker::PerformClassVerification(Thread* self,
	Handle<mirror::Class> klass,
	verifier::HardFailLogMode log_level,
	std::string* error_msg) {
	Runtime* const runtime = Runtime::Current();
	CompilerCallbacks* callbacks = runtime->GetCompilerCallbacks();
	ClassStatus old_status = callbacks->GetPreviousClassState(
	ClassReference(&klass->GetDexFile(), klass->GetDexClassDefIndex()));
	// Was it verified? Report no failure.
	if (old_status >= ClassStatus::kVerified) {
	return verifier::FailureKind::kNoFailure;
	}
	if (old_status >= ClassStatus::kVerifiedNeedsAccessChecks) {
	return verifier::FailureKind::kAccessChecksFailure;
	}
	// Does it need to be verified at runtime? Report soft failure.
	if (old_status >= ClassStatus::kRetryVerificationAtRuntime) {
	// Error messages from here are only reported through -verbose:class. It is not worth it to
	// create a message.
	return verifier::FailureKind::kSoftFailure;
	}
	// Do the actual work.
	return ClassLinker::PerformClassVerification(self, klass, log_level, error_msg);
	}

	bool AotClassLinker::CanReferenceInBootImageExtension(ObjPtr<mirror::Class> klass, gc::Heap* heap) {
	// Do not allow referencing a class or instance of a class defined in a dex file
	// belonging to the boot image we're compiling against but not itself in the boot image;
	// or a class referencing such classes as component type, superclass or interface.
	// Allowing this could yield duplicate class objects from multiple extensions.

	if (heap->ObjectIsInBootImageSpace(klass)) {
	return true; // Already included in the boot image we're compiling against.
	}

	// Treat arrays and primitive types specially because they do not have a DexCache that we
	// can use to check whether the dex file belongs to the boot image we're compiling against.
	DCHECK(!klass->IsPrimitive()); // Primitive classes must be in the primary boot image.
	if (klass->IsArrayClass()) {
	DCHECK(heap->ObjectIsInBootImageSpace(klass->GetIfTable())); // IfTable is OK.
	// Arrays of all dimensions are tied to the dex file of the non-array component type.
	do {
	klass = klass->GetComponentType();
	} while (klass->IsArrayClass());
	if (klass->IsPrimitive()) {
	return false;
	}
	// Do not allow arrays of erroneous classes (the array class is not itself erroneous).
	if (klass->IsErroneous()) {
	return false;
	}
	}

	// Check the class itself.
	if (heap->ObjectIsInBootImageSpace(klass->GetDexCache())) {
	return false;
	}

	// Check superclasses.
	ObjPtr<mirror::Class> superclass = klass->GetSuperClass();
	while (!heap->ObjectIsInBootImageSpace(superclass)) {
	DCHECK(superclass != nullptr); // Cannot skip Object which is in the primary boot image.
	if (heap->ObjectIsInBootImageSpace(superclass->GetDexCache())) {
	return false;
	}
	superclass = superclass->GetSuperClass();
	}

	// Check IfTable. This includes direct and indirect interfaces.
	ObjPtr<mirror::IfTable> if_table = klass->GetIfTable();
	for (size_t i = 0, num_interfaces = klass->GetIfTableCount(); i < num_interfaces; ++i) {
	ObjPtr<mirror::Class> interface = if_table->GetInterface(i);
	DCHECK(interface != nullptr);
	if (!heap->ObjectIsInBootImageSpace(interface) &&
	heap->ObjectIsInBootImageSpace(interface->GetDexCache())) {
	return false;
	}
	}

	if (kIsDebugBuild) {
	// All virtual methods must come from classes we have already checked above.
	PointerSize pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
	ObjPtr<mirror::Class> k = klass;
	while (!heap->ObjectIsInBootImageSpace(k)) {
	for (auto& m : k->GetVirtualMethods(pointer_size)) {
	ObjPtr<mirror::Class> declaring_class = m.GetDeclaringClass();
	CHECK(heap->ObjectIsInBootImageSpace(declaring_class) \|\|
	!heap->ObjectIsInBootImageSpace(declaring_class->GetDexCache()));
	}
	k = k->GetSuperClass();
	}
	}

	return true;
	}

	bool AotClassLinker::SetUpdatableBootClassPackages(const std::vector<std::string>& packages) {
	DCHECK(updatable_boot_class_path_descriptor_prefixes_.empty());
	// Transform package names to descriptor prefixes.
	std::vector<std::string> prefixes;
	prefixes.reserve(packages.size());
	for (const std::string& package : packages) {
	if (package.empty() \|\| package.find('/') != std::string::npos) {
	LOG(ERROR) << "Invalid package name: " << package;
	return false;
	}
	std::string prefix = 'L' + package + '/';
	std::replace(prefix.begin(), prefix.end(), '.', '/');
	prefixes.push_back(std::move(prefix));
	}
	// Sort and remove unnecessary prefixes.
	std::sort(prefixes.begin(), prefixes.end());
	std::string last_prefix;
	auto end_it = std::remove_if(
	prefixes.begin(),
	prefixes.end(),
	[&last_prefix](const std::string& s) {
	if (!last_prefix.empty() && StartsWith(s, last_prefix)) {
	return true;
	} else {
	last_prefix = s;
	return false;
	}
	});
	prefixes.resize(std::distance(prefixes.begin(), end_it));
	prefixes.shrink_to_fit();
	updatable_boot_class_path_descriptor_prefixes_.swap(prefixes);
	return true;
	}

	bool AotClassLinker::IsUpdatableBootClassPathDescriptor(const char* descriptor) {
	std::string_view descriptor_sv(descriptor);
	for (const std::string& prefix : updatable_boot_class_path_descriptor_prefixes_) {
	if (StartsWith(descriptor_sv, prefix)) {
	return true;
	}
	}
	return false;
	}

	} // namespace art