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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_Class.h"
18 
19 #include <iostream>
20 
21 #include "art_field-inl.h"
22 #include "art_method-inl.h"
23 #include "base/enums.h"
24 #include "class_linker-inl.h"
25 #include "common_throws.h"
26 #include "dex_file-inl.h"
27 #include "dex_file_annotations.h"
28 #include "jni_internal.h"
29 #include "nth_caller_visitor.h"
30 #include "mirror/class-inl.h"
31 #include "mirror/class_loader.h"
32 #include "mirror/field-inl.h"
33 #include "mirror/method.h"
34 #include "mirror/object-inl.h"
35 #include "mirror/object_array-inl.h"
36 #include "mirror/string-inl.h"
37 #include "obj_ptr-inl.h"
38 #include "reflection.h"
39 #include "scoped_thread_state_change-inl.h"
40 #include "scoped_fast_native_object_access-inl.h"
41 #include "ScopedLocalRef.h"
42 #include "ScopedUtfChars.h"
43 #include "utf.h"
44 #include "well_known_classes.h"
45 
46 namespace art {
47 
DecodeClass(const ScopedFastNativeObjectAccess & soa,jobject java_class)48 ALWAYS_INLINE static inline ObjPtr<mirror::Class> DecodeClass(
49     const ScopedFastNativeObjectAccess& soa, jobject java_class)
50     REQUIRES_SHARED(Locks::mutator_lock_) {
51   ObjPtr<mirror::Class> c = soa.Decode<mirror::Class>(java_class);
52   DCHECK(c != nullptr);
53   DCHECK(c->IsClass());
54   // TODO: we could EnsureInitialized here, rather than on every reflective get/set or invoke .
55   // For now, we conservatively preserve the old dalvik behavior. A quick "IsInitialized" check
56   // every time probably doesn't make much difference to reflection performance anyway.
57   return c;
58 }
59 
60 // "name" is in "binary name" format, e.g. "dalvik.system.Debug$1".
Class_classForName(JNIEnv * env,jclass,jstring javaName,jboolean initialize,jobject javaLoader)61 static jclass Class_classForName(JNIEnv* env, jclass, jstring javaName, jboolean initialize,
62                                  jobject javaLoader) {
63   ScopedFastNativeObjectAccess soa(env);
64   ScopedUtfChars name(env, javaName);
65   if (name.c_str() == nullptr) {
66     return nullptr;
67   }
68 
69   // We need to validate and convert the name (from x.y.z to x/y/z).  This
70   // is especially handy for array types, since we want to avoid
71   // auto-generating bogus array classes.
72   if (!IsValidBinaryClassName(name.c_str())) {
73     soa.Self()->ThrowNewExceptionF("Ljava/lang/ClassNotFoundException;",
74                                    "Invalid name: %s", name.c_str());
75     return nullptr;
76   }
77 
78   std::string descriptor(DotToDescriptor(name.c_str()));
79   StackHandleScope<2> hs(soa.Self());
80   Handle<mirror::ClassLoader> class_loader(
81       hs.NewHandle(soa.Decode<mirror::ClassLoader>(javaLoader)));
82   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
83   Handle<mirror::Class> c(
84       hs.NewHandle(class_linker->FindClass(soa.Self(), descriptor.c_str(), class_loader)));
85   if (c == nullptr) {
86     ScopedLocalRef<jthrowable> cause(env, env->ExceptionOccurred());
87     env->ExceptionClear();
88     jthrowable cnfe = reinterpret_cast<jthrowable>(
89         env->NewObject(WellKnownClasses::java_lang_ClassNotFoundException,
90                        WellKnownClasses::java_lang_ClassNotFoundException_init,
91                        javaName,
92                        cause.get()));
93     if (cnfe != nullptr) {
94       // Make sure allocation didn't fail with an OOME.
95       env->Throw(cnfe);
96     }
97     return nullptr;
98   }
99   if (initialize) {
100     class_linker->EnsureInitialized(soa.Self(), c, true, true);
101   }
102   return soa.AddLocalReference<jclass>(c.Get());
103 }
104 
Class_getNameNative(JNIEnv * env,jobject javaThis)105 static jstring Class_getNameNative(JNIEnv* env, jobject javaThis) {
106   ScopedFastNativeObjectAccess soa(env);
107   StackHandleScope<1> hs(soa.Self());
108   ObjPtr<mirror::Class> c = DecodeClass(soa, javaThis);
109   return soa.AddLocalReference<jstring>(mirror::Class::ComputeName(hs.NewHandle(c)));
110 }
111 
112 // TODO: Move this to mirror::Class ? Other mirror types that commonly appear
113 // as arrays have a GetArrayClass() method.
GetClassArrayClass(Thread * self)114 static ObjPtr<mirror::Class> GetClassArrayClass(Thread* self)
115     REQUIRES_SHARED(Locks::mutator_lock_) {
116   ObjPtr<mirror::Class> class_class = mirror::Class::GetJavaLangClass();
117   return Runtime::Current()->GetClassLinker()->FindArrayClass(self, &class_class);
118 }
119 
Class_getInterfacesInternal(JNIEnv * env,jobject javaThis)120 static jobjectArray Class_getInterfacesInternal(JNIEnv* env, jobject javaThis) {
121   ScopedFastNativeObjectAccess soa(env);
122   StackHandleScope<4> hs(soa.Self());
123   Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
124 
125   if (klass->IsProxyClass()) {
126     return soa.AddLocalReference<jobjectArray>(klass->GetProxyInterfaces()->Clone(soa.Self()));
127   }
128 
129   const DexFile::TypeList* iface_list = klass->GetInterfaceTypeList();
130   if (iface_list == nullptr) {
131     return nullptr;
132   }
133 
134   const uint32_t num_ifaces = iface_list->Size();
135   Handle<mirror::Class> class_array_class = hs.NewHandle(GetClassArrayClass(soa.Self()));
136   Handle<mirror::ObjectArray<mirror::Class>> ifaces = hs.NewHandle(
137       mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class.Get(), num_ifaces));
138   if (ifaces.IsNull()) {
139     DCHECK(soa.Self()->IsExceptionPending());
140     return nullptr;
141   }
142 
143   // Check that we aren't in an active transaction, we call SetWithoutChecks
144   // with kActiveTransaction == false.
145   DCHECK(!Runtime::Current()->IsActiveTransaction());
146 
147   MutableHandle<mirror::Class> interface(hs.NewHandle<mirror::Class>(nullptr));
148   for (uint32_t i = 0; i < num_ifaces; ++i) {
149     const dex::TypeIndex type_idx = iface_list->GetTypeItem(i).type_idx_;
150     interface.Assign(ClassLinker::LookupResolvedType(
151         type_idx, klass->GetDexCache(), klass->GetClassLoader()));
152     ifaces->SetWithoutChecks<false>(i, interface.Get());
153   }
154 
155   return soa.AddLocalReference<jobjectArray>(ifaces.Get());
156 }
157 
GetDeclaredFields(Thread * self,ObjPtr<mirror::Class> klass,bool public_only,bool force_resolve)158 static mirror::ObjectArray<mirror::Field>* GetDeclaredFields(
159     Thread* self, ObjPtr<mirror::Class> klass, bool public_only, bool force_resolve)
160       REQUIRES_SHARED(Locks::mutator_lock_) {
161   StackHandleScope<1> hs(self);
162   IterationRange<StrideIterator<ArtField>> ifields = klass->GetIFields();
163   IterationRange<StrideIterator<ArtField>> sfields = klass->GetSFields();
164   size_t array_size = klass->NumInstanceFields() + klass->NumStaticFields();
165   if (public_only) {
166     // Lets go subtract all the non public fields.
167     for (ArtField& field : ifields) {
168       if (!field.IsPublic()) {
169         --array_size;
170       }
171     }
172     for (ArtField& field : sfields) {
173       if (!field.IsPublic()) {
174         --array_size;
175       }
176     }
177   }
178   size_t array_idx = 0;
179   auto object_array = hs.NewHandle(mirror::ObjectArray<mirror::Field>::Alloc(
180       self, mirror::Field::ArrayClass(), array_size));
181   if (object_array == nullptr) {
182     return nullptr;
183   }
184   for (ArtField& field : ifields) {
185     if (!public_only || field.IsPublic()) {
186       auto* reflect_field = mirror::Field::CreateFromArtField<kRuntimePointerSize>(self,
187                                                                                    &field,
188                                                                                    force_resolve);
189       if (reflect_field == nullptr) {
190         if (kIsDebugBuild) {
191           self->AssertPendingException();
192         }
193         // Maybe null due to OOME or type resolving exception.
194         return nullptr;
195       }
196       object_array->SetWithoutChecks<false>(array_idx++, reflect_field);
197     }
198   }
199   for (ArtField& field : sfields) {
200     if (!public_only || field.IsPublic()) {
201       auto* reflect_field = mirror::Field::CreateFromArtField<kRuntimePointerSize>(self,
202                                                                                    &field,
203                                                                                    force_resolve);
204       if (reflect_field == nullptr) {
205         if (kIsDebugBuild) {
206           self->AssertPendingException();
207         }
208         return nullptr;
209       }
210       object_array->SetWithoutChecks<false>(array_idx++, reflect_field);
211     }
212   }
213   DCHECK_EQ(array_idx, array_size);
214   return object_array.Get();
215 }
216 
Class_getDeclaredFieldsUnchecked(JNIEnv * env,jobject javaThis,jboolean publicOnly)217 static jobjectArray Class_getDeclaredFieldsUnchecked(JNIEnv* env, jobject javaThis,
218                                                      jboolean publicOnly) {
219   ScopedFastNativeObjectAccess soa(env);
220   return soa.AddLocalReference<jobjectArray>(
221       GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), publicOnly != JNI_FALSE, false));
222 }
223 
Class_getDeclaredFields(JNIEnv * env,jobject javaThis)224 static jobjectArray Class_getDeclaredFields(JNIEnv* env, jobject javaThis) {
225   ScopedFastNativeObjectAccess soa(env);
226   return soa.AddLocalReference<jobjectArray>(
227       GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), false, true));
228 }
229 
Class_getPublicDeclaredFields(JNIEnv * env,jobject javaThis)230 static jobjectArray Class_getPublicDeclaredFields(JNIEnv* env, jobject javaThis) {
231   ScopedFastNativeObjectAccess soa(env);
232   return soa.AddLocalReference<jobjectArray>(
233       GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), true, true));
234 }
235 
236 // Performs a binary search through an array of fields, TODO: Is this fast enough if we don't use
237 // the dex cache for lookups? I think CompareModifiedUtf8ToUtf16AsCodePointValues should be fairly
238 // fast.
FindFieldByName(ObjPtr<mirror::String> name,LengthPrefixedArray<ArtField> * fields)239 ALWAYS_INLINE static inline ArtField* FindFieldByName(ObjPtr<mirror::String> name,
240                                                       LengthPrefixedArray<ArtField>* fields)
241     REQUIRES_SHARED(Locks::mutator_lock_) {
242   if (fields == nullptr) {
243     return nullptr;
244   }
245   size_t low = 0;
246   size_t high = fields->size();
247   const bool is_name_compressed = name->IsCompressed();
248   const uint16_t* const data = (is_name_compressed) ? nullptr : name->GetValue();
249   const uint8_t* const data_compressed = (is_name_compressed) ? name->GetValueCompressed()
250                                                               : nullptr;
251   const size_t length = name->GetLength();
252   while (low < high) {
253     auto mid = (low + high) / 2;
254     ArtField& field = fields->At(mid);
255     int result = 0;
256     if (is_name_compressed) {
257       size_t field_length = strlen(field.GetName());
258       size_t min_size = (length < field_length) ? length : field_length;
259       result = memcmp(field.GetName(), data_compressed, min_size);
260       if (result == 0) {
261         result = field_length - length;
262       }
263     } else {
264       result = CompareModifiedUtf8ToUtf16AsCodePointValues(field.GetName(), data, length);
265     }
266     // Alternate approach, only a few % faster at the cost of more allocations.
267     // int result = field->GetStringName(self, true)->CompareTo(name);
268     if (result < 0) {
269       low = mid + 1;
270     } else if (result > 0) {
271       high = mid;
272     } else {
273       return &field;
274     }
275   }
276   if (kIsDebugBuild) {
277     for (ArtField& field : MakeIterationRangeFromLengthPrefixedArray(fields)) {
278       CHECK_NE(field.GetName(), name->ToModifiedUtf8());
279     }
280   }
281   return nullptr;
282 }
283 
GetDeclaredField(Thread * self,ObjPtr<mirror::Class> c,ObjPtr<mirror::String> name)284 ALWAYS_INLINE static inline mirror::Field* GetDeclaredField(Thread* self,
285                                                             ObjPtr<mirror::Class> c,
286                                                             ObjPtr<mirror::String> name)
287     REQUIRES_SHARED(Locks::mutator_lock_) {
288   ArtField* art_field = FindFieldByName(name, c->GetIFieldsPtr());
289   if (art_field != nullptr) {
290     return mirror::Field::CreateFromArtField<kRuntimePointerSize>(self, art_field, true);
291   }
292   art_field = FindFieldByName(name, c->GetSFieldsPtr());
293   if (art_field != nullptr) {
294     return mirror::Field::CreateFromArtField<kRuntimePointerSize>(self, art_field, true);
295   }
296   return nullptr;
297 }
298 
GetPublicFieldRecursive(Thread * self,ObjPtr<mirror::Class> clazz,ObjPtr<mirror::String> name)299 static mirror::Field* GetPublicFieldRecursive(
300     Thread* self, ObjPtr<mirror::Class> clazz, ObjPtr<mirror::String> name)
301     REQUIRES_SHARED(Locks::mutator_lock_) {
302   DCHECK(clazz != nullptr);
303   DCHECK(name != nullptr);
304   DCHECK(self != nullptr);
305 
306   StackHandleScope<2> hs(self);
307   MutableHandle<mirror::Class> h_clazz(hs.NewHandle(clazz));
308   Handle<mirror::String> h_name(hs.NewHandle(name));
309 
310   // We search the current class, its direct interfaces then its superclass.
311   while (h_clazz != nullptr) {
312     mirror::Field* result = GetDeclaredField(self, h_clazz.Get(), h_name.Get());
313     if ((result != nullptr) && (result->GetAccessFlags() & kAccPublic)) {
314       return result;
315     } else if (UNLIKELY(self->IsExceptionPending())) {
316       // Something went wrong. Bail out.
317       return nullptr;
318     }
319 
320     uint32_t num_direct_interfaces = h_clazz->NumDirectInterfaces();
321     for (uint32_t i = 0; i < num_direct_interfaces; i++) {
322       ObjPtr<mirror::Class> iface = mirror::Class::ResolveDirectInterface(self, h_clazz, i);
323       if (UNLIKELY(iface == nullptr)) {
324         self->AssertPendingException();
325         return nullptr;
326       }
327       result = GetPublicFieldRecursive(self, iface, h_name.Get());
328       if (result != nullptr) {
329         DCHECK(result->GetAccessFlags() & kAccPublic);
330         return result;
331       } else if (UNLIKELY(self->IsExceptionPending())) {
332         // Something went wrong. Bail out.
333         return nullptr;
334       }
335     }
336 
337     // We don't try the superclass if we are an interface.
338     if (h_clazz->IsInterface()) {
339       break;
340     }
341 
342     // Get the next class.
343     h_clazz.Assign(h_clazz->GetSuperClass());
344   }
345   return nullptr;
346 }
347 
Class_getPublicFieldRecursive(JNIEnv * env,jobject javaThis,jstring name)348 static jobject Class_getPublicFieldRecursive(JNIEnv* env, jobject javaThis, jstring name) {
349   ScopedFastNativeObjectAccess soa(env);
350   auto name_string = soa.Decode<mirror::String>(name);
351   if (UNLIKELY(name_string == nullptr)) {
352     ThrowNullPointerException("name == null");
353     return nullptr;
354   }
355   return soa.AddLocalReference<jobject>(
356       GetPublicFieldRecursive(soa.Self(), DecodeClass(soa, javaThis), name_string));
357 }
358 
Class_getDeclaredField(JNIEnv * env,jobject javaThis,jstring name)359 static jobject Class_getDeclaredField(JNIEnv* env, jobject javaThis, jstring name) {
360   ScopedFastNativeObjectAccess soa(env);
361   StackHandleScope<3> hs(soa.Self());
362   Handle<mirror::String> h_string = hs.NewHandle(soa.Decode<mirror::String>(name));
363   if (h_string == nullptr) {
364     ThrowNullPointerException("name == null");
365     return nullptr;
366   }
367   Handle<mirror::Class> h_klass = hs.NewHandle(DecodeClass(soa, javaThis));
368   Handle<mirror::Field> result =
369       hs.NewHandle(GetDeclaredField(soa.Self(), h_klass.Get(), h_string.Get()));
370   if (result == nullptr) {
371     std::string name_str = h_string->ToModifiedUtf8();
372     if (name_str == "value" && h_klass->IsStringClass()) {
373       // We log the error for this specific case, as the user might just swallow the exception.
374       // This helps diagnose crashes when applications rely on the String#value field being
375       // there.
376       // Also print on the error stream to test it through run-test.
377       std::string message("The String#value field is not present on Android versions >= 6.0");
378       LOG(ERROR) << message;
379       std::cerr << message << std::endl;
380     }
381     // We may have a pending exception if we failed to resolve.
382     if (!soa.Self()->IsExceptionPending()) {
383       ThrowNoSuchFieldException(h_klass.Get(), name_str.c_str());
384     }
385     return nullptr;
386   }
387   return soa.AddLocalReference<jobject>(result.Get());
388 }
389 
Class_getDeclaredConstructorInternal(JNIEnv * env,jobject javaThis,jobjectArray args)390 static jobject Class_getDeclaredConstructorInternal(
391     JNIEnv* env, jobject javaThis, jobjectArray args) {
392   ScopedFastNativeObjectAccess soa(env);
393   DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
394   DCHECK(!Runtime::Current()->IsActiveTransaction());
395   ObjPtr<mirror::Constructor> result =
396       mirror::Class::GetDeclaredConstructorInternal<kRuntimePointerSize, false>(
397       soa.Self(),
398       DecodeClass(soa, javaThis),
399       soa.Decode<mirror::ObjectArray<mirror::Class>>(args));
400   return soa.AddLocalReference<jobject>(result);
401 }
402 
MethodMatchesConstructor(ArtMethod * m,bool public_only)403 static ALWAYS_INLINE inline bool MethodMatchesConstructor(ArtMethod* m, bool public_only)
404     REQUIRES_SHARED(Locks::mutator_lock_) {
405   DCHECK(m != nullptr);
406   return (!public_only || m->IsPublic()) && !m->IsStatic() && m->IsConstructor();
407 }
408 
Class_getDeclaredConstructorsInternal(JNIEnv * env,jobject javaThis,jboolean publicOnly)409 static jobjectArray Class_getDeclaredConstructorsInternal(
410     JNIEnv* env, jobject javaThis, jboolean publicOnly) {
411   ScopedFastNativeObjectAccess soa(env);
412   StackHandleScope<2> hs(soa.Self());
413   Handle<mirror::Class> h_klass = hs.NewHandle(DecodeClass(soa, javaThis));
414   size_t constructor_count = 0;
415   // Two pass approach for speed.
416   for (auto& m : h_klass->GetDirectMethods(kRuntimePointerSize)) {
417     constructor_count += MethodMatchesConstructor(&m, publicOnly != JNI_FALSE) ? 1u : 0u;
418   }
419   auto h_constructors = hs.NewHandle(mirror::ObjectArray<mirror::Constructor>::Alloc(
420       soa.Self(), mirror::Constructor::ArrayClass(), constructor_count));
421   if (UNLIKELY(h_constructors == nullptr)) {
422     soa.Self()->AssertPendingException();
423     return nullptr;
424   }
425   constructor_count = 0;
426   for (auto& m : h_klass->GetDirectMethods(kRuntimePointerSize)) {
427     if (MethodMatchesConstructor(&m, publicOnly != JNI_FALSE)) {
428       DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
429       DCHECK(!Runtime::Current()->IsActiveTransaction());
430       auto* constructor = mirror::Constructor::CreateFromArtMethod<kRuntimePointerSize, false>(
431           soa.Self(), &m);
432       if (UNLIKELY(constructor == nullptr)) {
433         soa.Self()->AssertPendingOOMException();
434         return nullptr;
435       }
436       h_constructors->SetWithoutChecks<false>(constructor_count++, constructor);
437     }
438   }
439   return soa.AddLocalReference<jobjectArray>(h_constructors.Get());
440 }
441 
Class_getDeclaredMethodInternal(JNIEnv * env,jobject javaThis,jobject name,jobjectArray args)442 static jobject Class_getDeclaredMethodInternal(JNIEnv* env, jobject javaThis,
443                                                jobject name, jobjectArray args) {
444   ScopedFastNativeObjectAccess soa(env);
445   DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
446   DCHECK(!Runtime::Current()->IsActiveTransaction());
447   ObjPtr<mirror::Method> result =
448       mirror::Class::GetDeclaredMethodInternal<kRuntimePointerSize, false>(
449           soa.Self(),
450           DecodeClass(soa, javaThis),
451           soa.Decode<mirror::String>(name),
452           soa.Decode<mirror::ObjectArray<mirror::Class>>(args));
453   return soa.AddLocalReference<jobject>(result);
454 }
455 
Class_getDeclaredMethodsUnchecked(JNIEnv * env,jobject javaThis,jboolean publicOnly)456 static jobjectArray Class_getDeclaredMethodsUnchecked(JNIEnv* env, jobject javaThis,
457                                                       jboolean publicOnly) {
458   ScopedFastNativeObjectAccess soa(env);
459   StackHandleScope<2> hs(soa.Self());
460   Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
461   size_t num_methods = 0;
462   for (auto& m : klass->GetDeclaredMethods(kRuntimePointerSize)) {
463     auto modifiers = m.GetAccessFlags();
464     // Add non-constructor declared methods.
465     if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
466         (modifiers & kAccConstructor) == 0) {
467       ++num_methods;
468     }
469   }
470   auto ret = hs.NewHandle(mirror::ObjectArray<mirror::Method>::Alloc(
471       soa.Self(), mirror::Method::ArrayClass(), num_methods));
472   if (ret == nullptr) {
473     soa.Self()->AssertPendingOOMException();
474     return nullptr;
475   }
476   num_methods = 0;
477   for (auto& m : klass->GetDeclaredMethods(kRuntimePointerSize)) {
478     auto modifiers = m.GetAccessFlags();
479     if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
480         (modifiers & kAccConstructor) == 0) {
481       DCHECK_EQ(Runtime::Current()->GetClassLinker()->GetImagePointerSize(), kRuntimePointerSize);
482       DCHECK(!Runtime::Current()->IsActiveTransaction());
483       auto* method =
484           mirror::Method::CreateFromArtMethod<kRuntimePointerSize, false>(soa.Self(), &m);
485       if (method == nullptr) {
486         soa.Self()->AssertPendingException();
487         return nullptr;
488       }
489       ret->SetWithoutChecks<false>(num_methods++, method);
490     }
491   }
492   return soa.AddLocalReference<jobjectArray>(ret.Get());
493 }
494 
Class_getDeclaredAnnotation(JNIEnv * env,jobject javaThis,jclass annotationClass)495 static jobject Class_getDeclaredAnnotation(JNIEnv* env, jobject javaThis, jclass annotationClass) {
496   ScopedFastNativeObjectAccess soa(env);
497   StackHandleScope<2> hs(soa.Self());
498   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
499 
500   // Handle public contract to throw NPE if the "annotationClass" argument was null.
501   if (UNLIKELY(annotationClass == nullptr)) {
502     ThrowNullPointerException("annotationClass");
503     return nullptr;
504   }
505 
506   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
507     return nullptr;
508   }
509   Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class>(annotationClass)));
510   return soa.AddLocalReference<jobject>(
511       annotations::GetAnnotationForClass(klass, annotation_class));
512 }
513 
Class_getDeclaredAnnotations(JNIEnv * env,jobject javaThis)514 static jobjectArray Class_getDeclaredAnnotations(JNIEnv* env, jobject javaThis) {
515   ScopedFastNativeObjectAccess soa(env);
516   StackHandleScope<1> hs(soa.Self());
517   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
518   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
519     // Return an empty array instead of a null pointer.
520     ObjPtr<mirror::Class>  annotation_array_class =
521         soa.Decode<mirror::Class>(WellKnownClasses::java_lang_annotation_Annotation__array);
522     mirror::ObjectArray<mirror::Object>* empty_array =
523         mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(),
524                                                    annotation_array_class.Ptr(),
525                                                    0);
526     return soa.AddLocalReference<jobjectArray>(empty_array);
527   }
528   return soa.AddLocalReference<jobjectArray>(annotations::GetAnnotationsForClass(klass));
529 }
530 
Class_getDeclaredClasses(JNIEnv * env,jobject javaThis)531 static jobjectArray Class_getDeclaredClasses(JNIEnv* env, jobject javaThis) {
532   ScopedFastNativeObjectAccess soa(env);
533   StackHandleScope<1> hs(soa.Self());
534   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
535   mirror::ObjectArray<mirror::Class>* classes = nullptr;
536   if (!klass->IsProxyClass() && klass->GetDexCache() != nullptr) {
537     classes = annotations::GetDeclaredClasses(klass);
538   }
539   if (classes == nullptr) {
540     // Return an empty array instead of a null pointer.
541     if (soa.Self()->IsExceptionPending()) {
542       // Pending exception from GetDeclaredClasses.
543       return nullptr;
544     }
545     ObjPtr<mirror::Class> class_array_class = GetClassArrayClass(soa.Self());
546     if (class_array_class == nullptr) {
547       return nullptr;
548     }
549     ObjPtr<mirror::ObjectArray<mirror::Class>> empty_array =
550         mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
551     return soa.AddLocalReference<jobjectArray>(empty_array);
552   }
553   return soa.AddLocalReference<jobjectArray>(classes);
554 }
555 
Class_getEnclosingClass(JNIEnv * env,jobject javaThis)556 static jclass Class_getEnclosingClass(JNIEnv* env, jobject javaThis) {
557   ScopedFastNativeObjectAccess soa(env);
558   StackHandleScope<1> hs(soa.Self());
559   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
560   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
561     return nullptr;
562   }
563   return soa.AddLocalReference<jclass>(annotations::GetEnclosingClass(klass));
564 }
565 
Class_getEnclosingConstructorNative(JNIEnv * env,jobject javaThis)566 static jobject Class_getEnclosingConstructorNative(JNIEnv* env, jobject javaThis) {
567   ScopedFastNativeObjectAccess soa(env);
568   StackHandleScope<1> hs(soa.Self());
569   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
570   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
571     return nullptr;
572   }
573   ObjPtr<mirror::Object> method = annotations::GetEnclosingMethod(klass);
574   if (method != nullptr) {
575     if (soa.Decode<mirror::Class>(WellKnownClasses::java_lang_reflect_Constructor) ==
576         method->GetClass()) {
577       return soa.AddLocalReference<jobject>(method);
578     }
579   }
580   return nullptr;
581 }
582 
Class_getEnclosingMethodNative(JNIEnv * env,jobject javaThis)583 static jobject Class_getEnclosingMethodNative(JNIEnv* env, jobject javaThis) {
584   ScopedFastNativeObjectAccess soa(env);
585   StackHandleScope<1> hs(soa.Self());
586   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
587   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
588     return nullptr;
589   }
590   ObjPtr<mirror::Object> method = annotations::GetEnclosingMethod(klass);
591   if (method != nullptr) {
592     if (soa.Decode<mirror::Class>(WellKnownClasses::java_lang_reflect_Method) ==
593         method->GetClass()) {
594       return soa.AddLocalReference<jobject>(method);
595     }
596   }
597   return nullptr;
598 }
599 
Class_getInnerClassFlags(JNIEnv * env,jobject javaThis,jint defaultValue)600 static jint Class_getInnerClassFlags(JNIEnv* env, jobject javaThis, jint defaultValue) {
601   ScopedFastNativeObjectAccess soa(env);
602   StackHandleScope<1> hs(soa.Self());
603   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
604   return mirror::Class::GetInnerClassFlags(klass, defaultValue);
605 }
606 
Class_getInnerClassName(JNIEnv * env,jobject javaThis)607 static jstring Class_getInnerClassName(JNIEnv* env, jobject javaThis) {
608   ScopedFastNativeObjectAccess soa(env);
609   StackHandleScope<1> hs(soa.Self());
610   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
611   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
612     return nullptr;
613   }
614   mirror::String* class_name = nullptr;
615   if (!annotations::GetInnerClass(klass, &class_name)) {
616     return nullptr;
617   }
618   return soa.AddLocalReference<jstring>(class_name);
619 }
620 
Class_getSignatureAnnotation(JNIEnv * env,jobject javaThis)621 static jobjectArray Class_getSignatureAnnotation(JNIEnv* env, jobject javaThis) {
622   ScopedFastNativeObjectAccess soa(env);
623   StackHandleScope<1> hs(soa.Self());
624   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
625   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
626     return nullptr;
627   }
628   return soa.AddLocalReference<jobjectArray>(
629       annotations::GetSignatureAnnotationForClass(klass));
630 }
631 
Class_isAnonymousClass(JNIEnv * env,jobject javaThis)632 static jboolean Class_isAnonymousClass(JNIEnv* env, jobject javaThis) {
633   ScopedFastNativeObjectAccess soa(env);
634   StackHandleScope<1> hs(soa.Self());
635   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
636   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
637     return false;
638   }
639   mirror::String* class_name = nullptr;
640   if (!annotations::GetInnerClass(klass, &class_name)) {
641     return false;
642   }
643   return class_name == nullptr;
644 }
645 
Class_isDeclaredAnnotationPresent(JNIEnv * env,jobject javaThis,jclass annotationType)646 static jboolean Class_isDeclaredAnnotationPresent(JNIEnv* env, jobject javaThis,
647                                                   jclass annotationType) {
648   ScopedFastNativeObjectAccess soa(env);
649   StackHandleScope<2> hs(soa.Self());
650   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
651   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
652     return false;
653   }
654   Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class>(annotationType)));
655   return annotations::IsClassAnnotationPresent(klass, annotation_class);
656 }
657 
Class_getDeclaringClass(JNIEnv * env,jobject javaThis)658 static jclass Class_getDeclaringClass(JNIEnv* env, jobject javaThis) {
659   ScopedFastNativeObjectAccess soa(env);
660   StackHandleScope<1> hs(soa.Self());
661   Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
662   if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
663     return nullptr;
664   }
665   // Return null for anonymous classes.
666   if (Class_isAnonymousClass(env, javaThis)) {
667     return nullptr;
668   }
669   return soa.AddLocalReference<jclass>(annotations::GetDeclaringClass(klass));
670 }
671 
Class_newInstance(JNIEnv * env,jobject javaThis)672 static jobject Class_newInstance(JNIEnv* env, jobject javaThis) {
673   ScopedFastNativeObjectAccess soa(env);
674   StackHandleScope<4> hs(soa.Self());
675   Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
676   if (UNLIKELY(klass->GetPrimitiveType() != 0 || klass->IsInterface() || klass->IsArrayClass() ||
677                klass->IsAbstract())) {
678     soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
679                                    "%s cannot be instantiated",
680                                    klass->PrettyClass().c_str());
681     return nullptr;
682   }
683   auto caller = hs.NewHandle<mirror::Class>(nullptr);
684   // Verify that we can access the class.
685   if (!klass->IsPublic()) {
686     caller.Assign(GetCallingClass(soa.Self(), 1));
687     if (caller != nullptr && !caller->CanAccess(klass.Get())) {
688       soa.Self()->ThrowNewExceptionF(
689           "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
690           klass->PrettyClass().c_str(), caller->PrettyClass().c_str());
691       return nullptr;
692     }
693   }
694   auto* constructor = klass->GetDeclaredConstructor(
695       soa.Self(),
696       ScopedNullHandle<mirror::ObjectArray<mirror::Class>>(),
697       kRuntimePointerSize);
698   if (UNLIKELY(constructor == nullptr)) {
699     soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
700                                    "%s has no zero argument constructor",
701                                    klass->PrettyClass().c_str());
702     return nullptr;
703   }
704   // Invoke the string allocator to return an empty string for the string class.
705   if (klass->IsStringClass()) {
706     gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
707     ObjPtr<mirror::Object> obj = mirror::String::AllocEmptyString<true>(soa.Self(), allocator_type);
708     if (UNLIKELY(soa.Self()->IsExceptionPending())) {
709       return nullptr;
710     } else {
711       return soa.AddLocalReference<jobject>(obj);
712     }
713   }
714   auto receiver = hs.NewHandle(klass->AllocObject(soa.Self()));
715   if (UNLIKELY(receiver == nullptr)) {
716     soa.Self()->AssertPendingOOMException();
717     return nullptr;
718   }
719   // Verify that we can access the constructor.
720   auto* declaring_class = constructor->GetDeclaringClass();
721   if (!constructor->IsPublic()) {
722     if (caller == nullptr) {
723       caller.Assign(GetCallingClass(soa.Self(), 1));
724     }
725     if (UNLIKELY(caller != nullptr && !VerifyAccess(receiver.Get(),
726                                                           declaring_class,
727                                                           constructor->GetAccessFlags(),
728                                                           caller.Get()))) {
729       soa.Self()->ThrowNewExceptionF(
730           "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
731           constructor->PrettyMethod().c_str(), caller->PrettyClass().c_str());
732       return nullptr;
733     }
734   }
735   // Ensure that we are initialized.
736   if (UNLIKELY(!declaring_class->IsInitialized())) {
737     if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(
738         soa.Self(), hs.NewHandle(declaring_class), true, true)) {
739       soa.Self()->AssertPendingException();
740       return nullptr;
741     }
742   }
743   // Invoke the constructor.
744   JValue result;
745   uint32_t args[1] = { static_cast<uint32_t>(reinterpret_cast<uintptr_t>(receiver.Get())) };
746   constructor->Invoke(soa.Self(), args, sizeof(args), &result, "V");
747   if (UNLIKELY(soa.Self()->IsExceptionPending())) {
748     return nullptr;
749   }
750   // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
751   return soa.AddLocalReference<jobject>(receiver.Get());
752 }
753 
754 static JNINativeMethod gMethods[] = {
755   FAST_NATIVE_METHOD(Class, classForName,
756                 "(Ljava/lang/String;ZLjava/lang/ClassLoader;)Ljava/lang/Class;"),
757   FAST_NATIVE_METHOD(Class, getDeclaredAnnotation,
758                 "(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;"),
759   FAST_NATIVE_METHOD(Class, getDeclaredAnnotations, "()[Ljava/lang/annotation/Annotation;"),
760   FAST_NATIVE_METHOD(Class, getDeclaredClasses, "()[Ljava/lang/Class;"),
761   FAST_NATIVE_METHOD(Class, getDeclaredConstructorInternal,
762                 "([Ljava/lang/Class;)Ljava/lang/reflect/Constructor;"),
763   FAST_NATIVE_METHOD(Class, getDeclaredConstructorsInternal, "(Z)[Ljava/lang/reflect/Constructor;"),
764   FAST_NATIVE_METHOD(Class, getDeclaredField, "(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
765   FAST_NATIVE_METHOD(Class, getPublicFieldRecursive, "(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
766   FAST_NATIVE_METHOD(Class, getDeclaredFields, "()[Ljava/lang/reflect/Field;"),
767   FAST_NATIVE_METHOD(Class, getDeclaredFieldsUnchecked, "(Z)[Ljava/lang/reflect/Field;"),
768   FAST_NATIVE_METHOD(Class, getDeclaredMethodInternal,
769                 "(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;"),
770   FAST_NATIVE_METHOD(Class, getDeclaredMethodsUnchecked,
771                 "(Z)[Ljava/lang/reflect/Method;"),
772   FAST_NATIVE_METHOD(Class, getDeclaringClass, "()Ljava/lang/Class;"),
773   FAST_NATIVE_METHOD(Class, getEnclosingClass, "()Ljava/lang/Class;"),
774   FAST_NATIVE_METHOD(Class, getEnclosingConstructorNative, "()Ljava/lang/reflect/Constructor;"),
775   FAST_NATIVE_METHOD(Class, getEnclosingMethodNative, "()Ljava/lang/reflect/Method;"),
776   FAST_NATIVE_METHOD(Class, getInnerClassFlags, "(I)I"),
777   FAST_NATIVE_METHOD(Class, getInnerClassName, "()Ljava/lang/String;"),
778   FAST_NATIVE_METHOD(Class, getInterfacesInternal, "()[Ljava/lang/Class;"),
779   FAST_NATIVE_METHOD(Class, getNameNative, "()Ljava/lang/String;"),
780   FAST_NATIVE_METHOD(Class, getPublicDeclaredFields, "()[Ljava/lang/reflect/Field;"),
781   FAST_NATIVE_METHOD(Class, getSignatureAnnotation, "()[Ljava/lang/String;"),
782   FAST_NATIVE_METHOD(Class, isAnonymousClass, "()Z"),
783   FAST_NATIVE_METHOD(Class, isDeclaredAnnotationPresent, "(Ljava/lang/Class;)Z"),
784   FAST_NATIVE_METHOD(Class, newInstance, "()Ljava/lang/Object;"),
785 };
786 
register_java_lang_Class(JNIEnv * env)787 void register_java_lang_Class(JNIEnv* env) {
788   REGISTER_NATIVE_METHODS("java/lang/Class");
789 }
790 
791 }  // namespace art
792