1/* 2 * Copyright (C) 2008 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 "java_lang_VMClassLoader.h" 18 19#include "class_linker.h" 20#include "dex/descriptors_names.h" 21#include "dex/dex_file_loader.h" 22#include "jni_internal.h" 23#include "mirror/class_loader.h" 24#include "mirror/object-inl.h" 25#include "native_util.h" 26#include "nativehelper/jni_macros.h" 27#include "nativehelper/scoped_local_ref.h" 28#include "nativehelper/scoped_utf_chars.h" 29#include "obj_ptr.h" 30#include "scoped_fast_native_object_access-inl.h" 31#include "well_known_classes.h" 32#include "zip_archive.h" 33 34namespace art { 35 36// A class so we can be friends with ClassLinker and access internal methods. 37class VMClassLoader { 38 public: 39 static mirror::Class* LookupClass(ClassLinker* cl, 40 Thread* self, 41 const char* descriptor, 42 size_t hash, 43 ObjPtr<mirror::ClassLoader> class_loader) 44 REQUIRES(!Locks::classlinker_classes_lock_) 45 REQUIRES_SHARED(Locks::mutator_lock_) { 46 return cl->LookupClass(self, descriptor, hash, class_loader); 47 } 48 49 static ObjPtr<mirror::Class> FindClassInPathClassLoader(ClassLinker* cl, 50 ScopedObjectAccessAlreadyRunnable& soa, 51 Thread* self, 52 const char* descriptor, 53 size_t hash, 54 Handle<mirror::ClassLoader> class_loader) 55 REQUIRES_SHARED(Locks::mutator_lock_) { 56 ObjPtr<mirror::Class> result; 57 if (cl->FindClassInBaseDexClassLoader(soa, self, descriptor, hash, class_loader, &result)) { 58 return result; 59 } 60 return nullptr; 61 } 62}; 63 64static jclass VMClassLoader_findLoadedClass(JNIEnv* env, jclass, jobject javaLoader, 65 jstring javaName) { 66 ScopedFastNativeObjectAccess soa(env); 67 ObjPtr<mirror::ClassLoader> loader = soa.Decode<mirror::ClassLoader>(javaLoader); 68 ScopedUtfChars name(env, javaName); 69 if (name.c_str() == nullptr) { 70 return nullptr; 71 } 72 ClassLinker* cl = Runtime::Current()->GetClassLinker(); 73 74 // Compute hash once. 75 std::string descriptor(DotToDescriptor(name.c_str())); 76 const size_t descriptor_hash = ComputeModifiedUtf8Hash(descriptor.c_str()); 77 78 ObjPtr<mirror::Class> c = VMClassLoader::LookupClass(cl, 79 soa.Self(), 80 descriptor.c_str(), 81 descriptor_hash, 82 loader); 83 if (c != nullptr && c->IsResolved()) { 84 return soa.AddLocalReference<jclass>(c); 85 } 86 // If class is erroneous, throw the earlier failure, wrapped in certain cases. See b/28787733. 87 if (c != nullptr && c->IsErroneous()) { 88 cl->ThrowEarlierClassFailure(c.Ptr()); 89 Thread* self = soa.Self(); 90 ObjPtr<mirror::Class> iae_class = 91 self->DecodeJObject(WellKnownClasses::java_lang_IllegalAccessError)->AsClass(); 92 ObjPtr<mirror::Class> ncdfe_class = 93 self->DecodeJObject(WellKnownClasses::java_lang_NoClassDefFoundError)->AsClass(); 94 ObjPtr<mirror::Class> exception = self->GetException()->GetClass(); 95 if (exception == iae_class || exception == ncdfe_class) { 96 self->ThrowNewWrappedException("Ljava/lang/ClassNotFoundException;", 97 c->PrettyDescriptor().c_str()); 98 } 99 return nullptr; 100 } 101 102 // Hard-coded performance optimization: We know that all failed libcore calls to findLoadedClass 103 // are followed by a call to the the classloader to actually 104 // load the class. 105 if (loader != nullptr) { 106 // Try the common case. 107 StackHandleScope<1> hs(soa.Self()); 108 c = VMClassLoader::FindClassInPathClassLoader(cl, 109 soa, 110 soa.Self(), 111 descriptor.c_str(), 112 descriptor_hash, 113 hs.NewHandle(loader)); 114 if (c != nullptr) { 115 return soa.AddLocalReference<jclass>(c); 116 } 117 } 118 119 // The class wasn't loaded, yet, and our fast-path did not apply (e.g., we didn't understand the 120 // classloader chain). 121 return nullptr; 122} 123 124/* 125 * Returns an array of entries from the boot classpath that could contain resources. 126 */ 127static jobjectArray VMClassLoader_getBootClassPathEntries(JNIEnv* env, jclass) { 128 const std::vector<const DexFile*>& path = 129 Runtime::Current()->GetClassLinker()->GetBootClassPath(); 130 jobjectArray array = 131 env->NewObjectArray(path.size(), WellKnownClasses::java_lang_String, nullptr); 132 if (array == nullptr) { 133 DCHECK(env->ExceptionCheck()); 134 return nullptr; 135 } 136 for (size_t i = 0; i < path.size(); ++i) { 137 const DexFile* dex_file = path[i]; 138 139 // For multidex locations, e.g., x.jar!classes2.dex, we want to look into x.jar. 140 const std::string location(DexFileLoader::GetBaseLocation(dex_file->GetLocation())); 141 142 ScopedLocalRef<jstring> javaPath(env, env->NewStringUTF(location.c_str())); 143 if (javaPath.get() == nullptr) { 144 DCHECK(env->ExceptionCheck()); 145 return nullptr; 146 } 147 env->SetObjectArrayElement(array, i, javaPath.get()); 148 } 149 return array; 150} 151 152static JNINativeMethod gMethods[] = { 153 FAST_NATIVE_METHOD(VMClassLoader, findLoadedClass, "(Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/Class;"), 154 NATIVE_METHOD(VMClassLoader, getBootClassPathEntries, "()[Ljava/lang/String;"), 155}; 156 157void register_java_lang_VMClassLoader(JNIEnv* env) { 158 REGISTER_NATIVE_METHODS("java/lang/VMClassLoader"); 159} 160 161} // namespace art 162