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/*
* Copyright (C) 2008 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 "java_lang_VMClassLoader.h"
#include "base/zip_archive.h"
#include "class_linker.h"
#include "base/transform_iterator.h"
#include "base/stl_util.h"
#include "dex/descriptors_names.h"
#include "dex/dex_file_loader.h"
#include "dex/utf.h"
#include "handle_scope-inl.h"
#include "jni/jni_internal.h"
#include "mirror/class_loader.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-alloc-inl.h"
#include "native_util.h"
#include "nativehelper/jni_macros.h"
#include "nativehelper/scoped_local_ref.h"
#include "nativehelper/scoped_utf_chars.h"
#include "obj_ptr.h"
#include "scoped_fast_native_object_access-inl.h"
#include "string_array_utils.h"
#include "thread-inl.h"
#include "well_known_classes-inl.h"
namespace art {
// A class so we can be friends with ClassLinker and access internal methods.
class VMClassLoader {
public:
static ObjPtr<mirror::Class> LookupClass(ClassLinker* cl,
Thread* self,
const char* descriptor,
size_t hash,
ObjPtr<mirror::ClassLoader> class_loader)
REQUIRES(!Locks::classlinker_classes_lock_)
REQUIRES_SHARED(Locks::mutator_lock_) {
return cl->LookupClass(self, descriptor, hash, class_loader);
}
static ObjPtr<mirror::Class> FindClassInPathClassLoader(ClassLinker* cl,
Thread* self,
const char* descriptor,
size_t hash,
Handle<mirror::ClassLoader> class_loader)
REQUIRES_SHARED(Locks::mutator_lock_) {
ObjPtr<mirror::Class> result;
if (cl->FindClassInBaseDexClassLoader(self, descriptor, hash, class_loader, &result)) {
DCHECK(!self->IsExceptionPending());
return result;
}
if (self->IsExceptionPending()) {
self->ClearException();
}
return nullptr;
}
};
static jclass VMClassLoader_findLoadedClass(JNIEnv* env, jclass, jobject javaLoader,
jstring javaName) {
ScopedFastNativeObjectAccess soa(env);
ObjPtr<mirror::ClassLoader> loader = soa.Decode<mirror::ClassLoader>(javaLoader);
ScopedUtfChars name(env, javaName);
if (name.c_str() == nullptr) {
return nullptr;
}
ClassLinker* cl = Runtime::Current()->GetClassLinker();
// Compute hash once.
std::string descriptor(DotToDescriptor(name.c_str()));
const size_t descriptor_hash = ComputeModifiedUtf8Hash(descriptor.c_str());
ObjPtr<mirror::Class> c = VMClassLoader::LookupClass(cl,
soa.Self(),
descriptor.c_str(),
descriptor_hash,
loader);
if (c != nullptr && c->IsResolved()) {
return soa.AddLocalReference<jclass>(c);
}
// If class is erroneous, throw the earlier failure, wrapped in certain cases. See b/28787733.
if (c != nullptr && c->IsErroneous()) {
cl->ThrowEarlierClassFailure(c);
Thread* self = soa.Self();
ObjPtr<mirror::Class> exception_class = self->GetException()->GetClass();
if (exception_class == WellKnownClasses::java_lang_IllegalAccessError ||
exception_class == WellKnownClasses::java_lang_NoClassDefFoundError) {
self->ThrowNewWrappedException("Ljava/lang/ClassNotFoundException;",
c->PrettyDescriptor().c_str());
}
return nullptr;
}
// Hard-coded performance optimization: We know that all failed libcore calls to findLoadedClass
// are followed by a call to the the classloader to actually
// load the class.
if (loader != nullptr) {
// Try the common case.
StackHandleScope<1> hs(soa.Self());
c = VMClassLoader::FindClassInPathClassLoader(cl,
soa.Self(),
descriptor.c_str(),
descriptor_hash,
hs.NewHandle(loader));
if (c != nullptr) {
return soa.AddLocalReference<jclass>(c);
}
}
// The class wasn't loaded, yet, and our fast-path did not apply (e.g., we didn't understand the
// classloader chain).
return nullptr;
}
/*
* Returns an array of entries from the boot classpath that could contain resources.
*/
static jobjectArray VMClassLoader_getBootClassPathEntries(JNIEnv* env, jclass) {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
const std::vector<const DexFile*>& path = class_linker->GetBootClassPath();
auto is_base_dex = [](const DexFile* dex_file) {
return !DexFileLoader::IsMultiDexLocation(dex_file->GetLocation().c_str());
};
size_t jar_count = std::count_if(path.begin(), path.end(), is_base_dex);
const DexFile* last_dex_file = nullptr;
auto dchecked_is_base_dex = [&](const DexFile* dex_file) {
// For multidex locations, e.g., x.jar!classes2.dex, we want to look into x.jar.
// But we do not need to look into the base dex file more than once so we filter
// out multidex locations using the fact that they follow the base location.
if (kIsDebugBuild) {
if (is_base_dex(dex_file)) {
CHECK_EQ(DexFileLoader::GetBaseLocation(dex_file->GetLocation().c_str()),
dex_file->GetLocation());
} else {
CHECK(last_dex_file != nullptr);
CHECK_EQ(DexFileLoader::GetBaseLocation(dex_file->GetLocation().c_str()),
DexFileLoader::GetBaseLocation(last_dex_file->GetLocation().c_str()));
}
last_dex_file = dex_file;
}
return is_base_dex(dex_file);
};
auto get_location = [](const DexFile* dex_file) { return dex_file->GetLocation(); };
ScopedObjectAccess soa(Thread::ForEnv(env));
return soa.AddLocalReference<jobjectArray>(CreateStringArray(
soa.Self(),
jar_count,
MakeTransformRange(Filter(path, dchecked_is_base_dex), get_location)));
}
static JNINativeMethod gMethods[] = {
FAST_NATIVE_METHOD(VMClassLoader, findLoadedClass, "(Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/Class;"),
NATIVE_METHOD(VMClassLoader, getBootClassPathEntries, "()[Ljava/lang/String;"),
};
void register_java_lang_VMClassLoader(JNIEnv* env) {
REGISTER_NATIVE_METHODS("java/lang/VMClassLoader");
}
} // namespace art