java_lang_Class.cc revision 08305325d3468d5ef413eb0b36b1ea1b3746a6c4 
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 "class_linker.h"
23#include "common_throws.h"
24#include "dex_file-inl.h"
25#include "jni_internal.h"
26#include "nth_caller_visitor.h"
27#include "mirror/class-inl.h"
28#include "mirror/class_loader.h"
29#include "mirror/field-inl.h"
30#include "mirror/method.h"
31#include "mirror/object-inl.h"
32#include "mirror/object_array-inl.h"
33#include "mirror/string-inl.h"
34#include "reflection.h"
35#include "scoped_thread_state_change.h"
36#include "scoped_fast_native_object_access.h"
37#include "ScopedLocalRef.h"
38#include "ScopedUtfChars.h"
39#include "utf.h"
40#include "well_known_classes.h"
41
42namespace art {
43
44ALWAYS_INLINE static inline mirror::Class* DecodeClass(
45    const ScopedFastNativeObjectAccess& soa, jobject java_class)
46    SHARED_REQUIRES(Locks::mutator_lock_) {
47  mirror::Class* c = soa.Decode<mirror::Class*>(java_class);
48  DCHECK(c != nullptr);
49  DCHECK(c->IsClass());
50  // TODO: we could EnsureInitialized here, rather than on every reflective get/set or invoke .
51  // For now, we conservatively preserve the old dalvik behavior. A quick "IsInitialized" check
52  // every time probably doesn't make much difference to reflection performance anyway.
53  return c;
54}
55
56// "name" is in "binary name" format, e.g. "dalvik.system.Debug$1".
57static jclass Class_classForName(JNIEnv* env, jclass, jstring javaName, jboolean initialize,
58                                 jobject javaLoader) {
59  ScopedFastNativeObjectAccess soa(env);
60  ScopedUtfChars name(env, javaName);
61  if (name.c_str() == nullptr) {
62    return nullptr;
63  }
64
65  // We need to validate and convert the name (from x.y.z to x/y/z).  This
66  // is especially handy for array types, since we want to avoid
67  // auto-generating bogus array classes.
68  if (!IsValidBinaryClassName(name.c_str())) {
69    soa.Self()->ThrowNewExceptionF("Ljava/lang/ClassNotFoundException;",
70                                   "Invalid name: %s", name.c_str());
71    return nullptr;
72  }
73
74  std::string descriptor(DotToDescriptor(name.c_str()));
75  StackHandleScope<2> hs(soa.Self());
76  Handle<mirror::ClassLoader> class_loader(hs.NewHandle(soa.Decode<mirror::ClassLoader*>(javaLoader)));
77  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
78  Handle<mirror::Class> c(
79      hs.NewHandle(class_linker->FindClass(soa.Self(), descriptor.c_str(), class_loader)));
80  if (c.Get() == nullptr) {
81    ScopedLocalRef<jthrowable> cause(env, env->ExceptionOccurred());
82    env->ExceptionClear();
83    jthrowable cnfe = reinterpret_cast<jthrowable>(env->NewObject(WellKnownClasses::java_lang_ClassNotFoundException,
84                                                                  WellKnownClasses::java_lang_ClassNotFoundException_init,
85                                                                  javaName, cause.get()));
86    if (cnfe != nullptr) {
87      // Make sure allocation didn't fail with an OOME.
88      env->Throw(cnfe);
89    }
90    return nullptr;
91  }
92  if (initialize) {
93    class_linker->EnsureInitialized(soa.Self(), c, true, true);
94  }
95  return soa.AddLocalReference<jclass>(c.Get());
96}
97
98static jstring Class_getNameNative(JNIEnv* env, jobject javaThis) {
99  ScopedFastNativeObjectAccess soa(env);
100  StackHandleScope<1> hs(soa.Self());
101  mirror::Class* const c = DecodeClass(soa, javaThis);
102  return soa.AddLocalReference<jstring>(mirror::Class::ComputeName(hs.NewHandle(c)));
103}
104
105static jobjectArray Class_getProxyInterfaces(JNIEnv* env, jobject javaThis) {
106  ScopedFastNativeObjectAccess soa(env);
107  mirror::Class* c = DecodeClass(soa, javaThis);
108  return soa.AddLocalReference<jobjectArray>(c->GetInterfaces()->Clone(soa.Self()));
109}
110
111static mirror::ObjectArray<mirror::Field>* GetDeclaredFields(
112    Thread* self, mirror::Class* klass, bool public_only, bool force_resolve)
113      SHARED_REQUIRES(Locks::mutator_lock_) {
114  StackHandleScope<1> hs(self);
115  IterationRange<StrideIterator<ArtField>> ifields = klass->GetIFields();
116  IterationRange<StrideIterator<ArtField>> sfields = klass->GetSFields();
117  size_t array_size = klass->NumInstanceFields() + klass->NumStaticFields();
118  if (public_only) {
119    // Lets go subtract all the non public fields.
120    for (ArtField& field : ifields) {
121      if (!field.IsPublic()) {
122        --array_size;
123      }
124    }
125    for (ArtField& field : sfields) {
126      if (!field.IsPublic()) {
127        --array_size;
128      }
129    }
130  }
131  size_t array_idx = 0;
132  auto object_array = hs.NewHandle(mirror::ObjectArray<mirror::Field>::Alloc(
133      self, mirror::Field::ArrayClass(), array_size));
134  if (object_array.Get() == nullptr) {
135    return nullptr;
136  }
137  for (ArtField& field : ifields) {
138    if (!public_only || field.IsPublic()) {
139      auto* reflect_field = mirror::Field::CreateFromArtField(self, &field, force_resolve);
140      if (reflect_field == nullptr) {
141        if (kIsDebugBuild) {
142          self->AssertPendingException();
143        }
144        // Maybe null due to OOME or type resolving exception.
145        return nullptr;
146      }
147      object_array->SetWithoutChecks<false>(array_idx++, reflect_field);
148    }
149  }
150  for (ArtField& field : sfields) {
151    if (!public_only || field.IsPublic()) {
152      auto* reflect_field = mirror::Field::CreateFromArtField(self, &field, force_resolve);
153      if (reflect_field == nullptr) {
154        if (kIsDebugBuild) {
155          self->AssertPendingException();
156        }
157        return nullptr;
158      }
159      object_array->SetWithoutChecks<false>(array_idx++, reflect_field);
160    }
161  }
162  DCHECK_EQ(array_idx, array_size);
163  return object_array.Get();
164}
165
166static jobjectArray Class_getDeclaredFieldsUnchecked(JNIEnv* env, jobject javaThis,
167                                                     jboolean publicOnly) {
168  ScopedFastNativeObjectAccess soa(env);
169  return soa.AddLocalReference<jobjectArray>(
170      GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), publicOnly != JNI_FALSE, false));
171}
172
173static jobjectArray Class_getDeclaredFields(JNIEnv* env, jobject javaThis) {
174  ScopedFastNativeObjectAccess soa(env);
175  return soa.AddLocalReference<jobjectArray>(
176      GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), false, true));
177}
178
179static jobjectArray Class_getPublicDeclaredFields(JNIEnv* env, jobject javaThis) {
180  ScopedFastNativeObjectAccess soa(env);
181  return soa.AddLocalReference<jobjectArray>(
182      GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), true, true));
183}
184
185// Performs a binary search through an array of fields, TODO: Is this fast enough if we don't use
186// the dex cache for lookups? I think CompareModifiedUtf8ToUtf16AsCodePointValues should be fairly
187// fast.
188ALWAYS_INLINE static inline ArtField* FindFieldByName(
189    Thread* self ATTRIBUTE_UNUSED, mirror::String* name, LengthPrefixedArray<ArtField>* fields)
190    SHARED_REQUIRES(Locks::mutator_lock_) {
191  if (fields == nullptr) {
192    return nullptr;
193  }
194  size_t low = 0;
195  size_t high = fields->size();
196  const uint16_t* const data = name->GetValue();
197  const size_t length = name->GetLength();
198  while (low < high) {
199    auto mid = (low + high) / 2;
200    ArtField& field = fields->At(mid);
201    int result = CompareModifiedUtf8ToUtf16AsCodePointValues(field.GetName(), data, length);
202    // Alternate approach, only a few % faster at the cost of more allocations.
203    // int result = field->GetStringName(self, true)->CompareTo(name);
204    if (result < 0) {
205      low = mid + 1;
206    } else if (result > 0) {
207      high = mid;
208    } else {
209      return &field;
210    }
211  }
212  if (kIsDebugBuild) {
213    for (ArtField& field : MakeIterationRangeFromLengthPrefixedArray(fields)) {
214      CHECK_NE(field.GetName(), name->ToModifiedUtf8());
215    }
216  }
217  return nullptr;
218}
219
220ALWAYS_INLINE static inline mirror::Field* GetDeclaredField(
221    Thread* self, mirror::Class* c, mirror::String* name)
222    SHARED_REQUIRES(Locks::mutator_lock_) {
223  ArtField* art_field = FindFieldByName(self, name, c->GetIFieldsPtr());
224  if (art_field != nullptr) {
225    return mirror::Field::CreateFromArtField(self, art_field, true);
226  }
227  art_field = FindFieldByName(self, name, c->GetSFieldsPtr());
228  if (art_field != nullptr) {
229    return mirror::Field::CreateFromArtField(self, art_field, true);
230  }
231  return nullptr;
232}
233
234static mirror::Field* GetPublicFieldRecursive(
235    Thread* self, mirror::Class* clazz, mirror::String* name)
236    SHARED_REQUIRES(Locks::mutator_lock_) {
237  DCHECK(clazz != nullptr);
238  DCHECK(name != nullptr);
239  DCHECK(self != nullptr);
240
241  StackHandleScope<1> hs(self);
242  MutableHandle<mirror::Class> h_clazz(hs.NewHandle(clazz));
243
244  // We search the current class, its direct interfaces then its superclass.
245  while (h_clazz.Get() != nullptr) {
246    mirror::Field* result = GetDeclaredField(self, h_clazz.Get(), name);
247    if ((result != nullptr) && (result->GetAccessFlags() & kAccPublic)) {
248      return result;
249    } else if (UNLIKELY(self->IsExceptionPending())) {
250      // Something went wrong. Bail out.
251      return nullptr;
252    }
253
254    uint32_t num_direct_interfaces = h_clazz->NumDirectInterfaces();
255    for (uint32_t i = 0; i < num_direct_interfaces; i++) {
256      mirror::Class *iface = mirror::Class::GetDirectInterface(self, h_clazz, i);
257      if (UNLIKELY(iface == nullptr)) {
258        self->AssertPendingException();
259        return nullptr;
260      }
261      result = GetPublicFieldRecursive(self, iface, name);
262      if (result != nullptr) {
263        DCHECK(result->GetAccessFlags() & kAccPublic);
264        return result;
265      } else if (UNLIKELY(self->IsExceptionPending())) {
266        // Something went wrong. Bail out.
267        return nullptr;
268      }
269    }
270
271    // We don't try the superclass if we are an interface.
272    if (h_clazz->IsInterface()) {
273      break;
274    }
275
276    // Get the next class.
277    h_clazz.Assign(h_clazz->GetSuperClass());
278  }
279  return nullptr;
280}
281
282static jobject Class_getPublicFieldRecursive(JNIEnv* env, jobject javaThis, jstring name) {
283  ScopedFastNativeObjectAccess soa(env);
284  auto* name_string = soa.Decode<mirror::String*>(name);
285  if (UNLIKELY(name_string == nullptr)) {
286    ThrowNullPointerException("name == null");
287    return nullptr;
288  }
289  return soa.AddLocalReference<jobject>(
290      GetPublicFieldRecursive(soa.Self(), DecodeClass(soa, javaThis), name_string));
291}
292
293static jobject Class_getDeclaredField(JNIEnv* env, jobject javaThis, jstring name) {
294  ScopedFastNativeObjectAccess soa(env);
295  auto* name_string = soa.Decode<mirror::String*>(name);
296  if (name_string == nullptr) {
297    ThrowNullPointerException("name == null");
298    return nullptr;
299  }
300  auto* klass = DecodeClass(soa, javaThis);
301  mirror::Field* result = GetDeclaredField(soa.Self(), klass, name_string);
302  if (result == nullptr) {
303    std::string name_str = name_string->ToModifiedUtf8();
304    if (name_str == "value" && klass->IsStringClass()) {
305      // We log the error for this specific case, as the user might just swallow the exception.
306      // This helps diagnose crashes when applications rely on the String#value field being
307      // there.
308      // Also print on the error stream to test it through run-test.
309      std::string message("The String#value field is not present on Android versions >= 6.0");
310      LOG(ERROR) << message;
311      std::cerr << message << std::endl;
312    }
313    // We may have a pending exception if we failed to resolve.
314    if (!soa.Self()->IsExceptionPending()) {
315      ThrowNoSuchFieldException(DecodeClass(soa, javaThis), name_str.c_str());
316    }
317    return nullptr;
318  }
319  return soa.AddLocalReference<jobject>(result);
320}
321
322static jobject Class_getDeclaredConstructorInternal(
323    JNIEnv* env, jobject javaThis, jobjectArray args) {
324  ScopedFastNativeObjectAccess soa(env);
325  mirror::Constructor* result = mirror::Class::GetDeclaredConstructorInternal(
326      soa.Self(),
327      DecodeClass(soa, javaThis),
328      soa.Decode<mirror::ObjectArray<mirror::Class>*>(args));
329  return soa.AddLocalReference<jobject>(result);
330}
331
332static ALWAYS_INLINE inline bool MethodMatchesConstructor(ArtMethod* m, bool public_only)
333    SHARED_REQUIRES(Locks::mutator_lock_) {
334  DCHECK(m != nullptr);
335  return (!public_only || m->IsPublic()) && !m->IsStatic() && m->IsConstructor();
336}
337
338static jobjectArray Class_getDeclaredConstructorsInternal(
339    JNIEnv* env, jobject javaThis, jboolean publicOnly) {
340  ScopedFastNativeObjectAccess soa(env);
341  StackHandleScope<2> hs(soa.Self());
342  Handle<mirror::Class> h_klass = hs.NewHandle(DecodeClass(soa, javaThis));
343  size_t constructor_count = 0;
344  // Two pass approach for speed.
345  for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
346    constructor_count += MethodMatchesConstructor(&m, publicOnly != JNI_FALSE) ? 1u : 0u;
347  }
348  auto h_constructors = hs.NewHandle(mirror::ObjectArray<mirror::Constructor>::Alloc(
349      soa.Self(), mirror::Constructor::ArrayClass(), constructor_count));
350  if (UNLIKELY(h_constructors.Get() == nullptr)) {
351    soa.Self()->AssertPendingException();
352    return nullptr;
353  }
354  constructor_count = 0;
355  for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
356    if (MethodMatchesConstructor(&m, publicOnly != JNI_FALSE)) {
357      auto* constructor = mirror::Constructor::CreateFromArtMethod(soa.Self(), &m);
358      if (UNLIKELY(constructor == nullptr)) {
359        soa.Self()->AssertPendingOOMException();
360        return nullptr;
361      }
362      h_constructors->SetWithoutChecks<false>(constructor_count++, constructor);
363    }
364  }
365  return soa.AddLocalReference<jobjectArray>(h_constructors.Get());
366}
367
368static jobject Class_getDeclaredMethodInternal(JNIEnv* env, jobject javaThis,
369                                               jobject name, jobjectArray args) {
370  ScopedFastNativeObjectAccess soa(env);
371  mirror::Method* result = mirror::Class::GetDeclaredMethodInternal(
372      soa.Self(),
373      DecodeClass(soa, javaThis),
374      soa.Decode<mirror::String*>(name),
375      soa.Decode<mirror::ObjectArray<mirror::Class>*>(args));
376  return soa.AddLocalReference<jobject>(result);
377}
378
379static jobjectArray Class_getDeclaredMethodsUnchecked(JNIEnv* env, jobject javaThis,
380                                                      jboolean publicOnly) {
381  ScopedFastNativeObjectAccess soa(env);
382  StackHandleScope<2> hs(soa.Self());
383  Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
384  size_t num_methods = 0;
385  for (auto& m : klass->GetDeclaredMethods(sizeof(void*))) {
386    auto modifiers = m.GetAccessFlags();
387    // Add non-constructor declared methods.
388    if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
389        (modifiers & kAccConstructor) == 0) {
390      ++num_methods;
391    }
392  }
393  auto ret = hs.NewHandle(mirror::ObjectArray<mirror::Method>::Alloc(
394      soa.Self(), mirror::Method::ArrayClass(), num_methods));
395  num_methods = 0;
396  for (auto& m : klass->GetDeclaredMethods(sizeof(void*))) {
397    auto modifiers = m.GetAccessFlags();
398    if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
399        (modifiers & kAccConstructor) == 0) {
400      auto* method = mirror::Method::CreateFromArtMethod(soa.Self(), &m);
401      if (method == nullptr) {
402        soa.Self()->AssertPendingException();
403        return nullptr;
404      }
405      ret->SetWithoutChecks<false>(num_methods++, method);
406    }
407  }
408  return soa.AddLocalReference<jobjectArray>(ret.Get());
409}
410
411static jobject Class_getDeclaredAnnotation(JNIEnv* env, jobject javaThis, jclass annotationClass) {
412  ScopedFastNativeObjectAccess soa(env);
413  StackHandleScope<2> hs(soa.Self());
414  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
415
416  // Handle public contract to throw NPE if the "annotationClass" argument was null.
417  if (UNLIKELY(annotationClass == nullptr)) {
418    ThrowNullPointerException("annotationClass");
419    return nullptr;
420  }
421
422  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
423    return nullptr;
424  }
425  Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class*>(annotationClass)));
426  return soa.AddLocalReference<jobject>(
427      klass->GetDexFile().GetAnnotationForClass(klass, annotation_class));
428}
429
430static jobjectArray Class_getDeclaredAnnotations(JNIEnv* env, jobject javaThis) {
431  ScopedFastNativeObjectAccess soa(env);
432  StackHandleScope<1> hs(soa.Self());
433  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
434  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
435    // Return an empty array instead of a null pointer.
436    mirror::Class* annotation_array_class =
437        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_annotation_Annotation__array);
438    mirror::ObjectArray<mirror::Object>* empty_array =
439        mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), annotation_array_class, 0);
440    return soa.AddLocalReference<jobjectArray>(empty_array);
441  }
442  return soa.AddLocalReference<jobjectArray>(klass->GetDexFile().GetAnnotationsForClass(klass));
443}
444
445static jobjectArray Class_getDeclaredClasses(JNIEnv* env, jobject javaThis) {
446  ScopedFastNativeObjectAccess soa(env);
447  StackHandleScope<1> hs(soa.Self());
448  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
449  mirror::ObjectArray<mirror::Class>* classes = nullptr;
450  if (!klass->IsProxyClass() && klass->GetDexCache() != nullptr) {
451    classes = klass->GetDexFile().GetDeclaredClasses(klass);
452  }
453  if (classes == nullptr) {
454    // Return an empty array instead of a null pointer.
455    if (soa.Self()->IsExceptionPending()) {
456      // Pending exception from GetDeclaredClasses.
457      return nullptr;
458    }
459    mirror::Class* class_class = mirror::Class::GetJavaLangClass();
460    mirror::Class* class_array_class =
461        Runtime::Current()->GetClassLinker()->FindArrayClass(soa.Self(), &class_class);
462    if (class_array_class == nullptr) {
463      return nullptr;
464    }
465    mirror::ObjectArray<mirror::Class>* empty_array =
466        mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
467    return soa.AddLocalReference<jobjectArray>(empty_array);
468  }
469  return soa.AddLocalReference<jobjectArray>(classes);
470}
471
472static jclass Class_getEnclosingClass(JNIEnv* env, jobject javaThis) {
473  ScopedFastNativeObjectAccess soa(env);
474  StackHandleScope<1> hs(soa.Self());
475  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
476  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
477    return nullptr;
478  }
479  return soa.AddLocalReference<jclass>(klass->GetDexFile().GetEnclosingClass(klass));
480}
481
482static jobject Class_getEnclosingConstructorNative(JNIEnv* env, jobject javaThis) {
483  ScopedFastNativeObjectAccess soa(env);
484  StackHandleScope<1> hs(soa.Self());
485  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
486  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
487    return nullptr;
488  }
489  mirror::Object* method = klass->GetDexFile().GetEnclosingMethod(klass);
490  if (method != nullptr) {
491    if (method->GetClass() ==
492        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_reflect_Constructor)) {
493      return soa.AddLocalReference<jobject>(method);
494    }
495  }
496  return nullptr;
497}
498
499static jobject Class_getEnclosingMethodNative(JNIEnv* env, jobject javaThis) {
500  ScopedFastNativeObjectAccess soa(env);
501  StackHandleScope<1> hs(soa.Self());
502  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
503  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
504    return nullptr;
505  }
506  mirror::Object* method = klass->GetDexFile().GetEnclosingMethod(klass);
507  if (method != nullptr) {
508    if (method->GetClass() ==
509        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_reflect_Method)) {
510      return soa.AddLocalReference<jobject>(method);
511    }
512  }
513  return nullptr;
514}
515
516static jint Class_getInnerClassFlags(JNIEnv* env, jobject javaThis, jint defaultValue) {
517  ScopedFastNativeObjectAccess soa(env);
518  StackHandleScope<1> hs(soa.Self());
519  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
520  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
521    return defaultValue;
522  }
523  uint32_t flags;
524  if (!klass->GetDexFile().GetInnerClassFlags(klass, &flags)) {
525    return defaultValue;
526  }
527  return flags;
528}
529
530static jstring Class_getInnerClassName(JNIEnv* env, jobject javaThis) {
531  ScopedFastNativeObjectAccess soa(env);
532  StackHandleScope<1> hs(soa.Self());
533  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
534  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
535    return nullptr;
536  }
537  mirror::String* class_name = nullptr;
538  if (!klass->GetDexFile().GetInnerClass(klass, &class_name)) {
539    return nullptr;
540  }
541  return soa.AddLocalReference<jstring>(class_name);
542}
543
544static jobjectArray Class_getSignatureAnnotation(JNIEnv* env, jobject javaThis) {
545  ScopedFastNativeObjectAccess soa(env);
546  StackHandleScope<1> hs(soa.Self());
547  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
548  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
549    return nullptr;
550  }
551  return soa.AddLocalReference<jobjectArray>(
552      klass->GetDexFile().GetSignatureAnnotationForClass(klass));
553}
554
555static jboolean Class_isAnonymousClass(JNIEnv* env, jobject javaThis) {
556  ScopedFastNativeObjectAccess soa(env);
557  StackHandleScope<1> hs(soa.Self());
558  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
559  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
560    return false;
561  }
562  mirror::String* class_name = nullptr;
563  if (!klass->GetDexFile().GetInnerClass(klass, &class_name)) {
564    return false;
565  }
566  return class_name == nullptr;
567}
568
569static jboolean Class_isDeclaredAnnotationPresent(JNIEnv* env, jobject javaThis,
570                                                  jclass annotationType) {
571  ScopedFastNativeObjectAccess soa(env);
572  StackHandleScope<2> hs(soa.Self());
573  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
574  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
575    return false;
576  }
577  Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class*>(annotationType)));
578  return klass->GetDexFile().IsClassAnnotationPresent(klass, annotation_class);
579}
580
581static jclass Class_getDeclaringClass(JNIEnv* env, jobject javaThis) {
582  ScopedFastNativeObjectAccess soa(env);
583  StackHandleScope<1> hs(soa.Self());
584  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
585  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
586    return nullptr;
587  }
588  // Return null for anonymous classes.
589  if (Class_isAnonymousClass(env, javaThis)) {
590    return nullptr;
591  }
592  return soa.AddLocalReference<jclass>(klass->GetDexFile().GetDeclaringClass(klass));
593}
594
595static jobject Class_newInstance(JNIEnv* env, jobject javaThis) {
596  ScopedFastNativeObjectAccess soa(env);
597  StackHandleScope<4> hs(soa.Self());
598  Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
599  if (UNLIKELY(klass->GetPrimitiveType() != 0 || klass->IsInterface() || klass->IsArrayClass() ||
600               klass->IsAbstract())) {
601    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
602                                   "%s cannot be instantiated", PrettyClass(klass.Get()).c_str());
603    return nullptr;
604  }
605  auto caller = hs.NewHandle<mirror::Class>(nullptr);
606  // Verify that we can access the class.
607  if (!klass->IsPublic()) {
608    caller.Assign(GetCallingClass(soa.Self(), 1));
609    if (caller.Get() != nullptr && !caller->CanAccess(klass.Get())) {
610      soa.Self()->ThrowNewExceptionF(
611          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
612          PrettyClass(klass.Get()).c_str(), PrettyClass(caller.Get()).c_str());
613      return nullptr;
614    }
615  }
616  auto* constructor = klass->GetDeclaredConstructor(
617      soa.Self(),
618      ScopedNullHandle<mirror::ObjectArray<mirror::Class>>(),
619      sizeof(void*));
620  if (UNLIKELY(constructor == nullptr)) {
621    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
622                                   "%s has no zero argument constructor",
623                                   PrettyClass(klass.Get()).c_str());
624    return nullptr;
625  }
626  // Invoke the string allocator to return an empty string for the string class.
627  if (klass->IsStringClass()) {
628    gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
629    mirror::SetStringCountVisitor visitor(0);
630    mirror::Object* obj = mirror::String::Alloc<true>(soa.Self(), 0, allocator_type, visitor);
631    if (UNLIKELY(soa.Self()->IsExceptionPending())) {
632      return nullptr;
633    } else {
634      return soa.AddLocalReference<jobject>(obj);
635    }
636  }
637  auto receiver = hs.NewHandle(klass->AllocObject(soa.Self()));
638  if (UNLIKELY(receiver.Get() == nullptr)) {
639    soa.Self()->AssertPendingOOMException();
640    return nullptr;
641  }
642  // Verify that we can access the constructor.
643  auto* declaring_class = constructor->GetDeclaringClass();
644  if (!constructor->IsPublic()) {
645    if (caller.Get() == nullptr) {
646      caller.Assign(GetCallingClass(soa.Self(), 1));
647    }
648    if (UNLIKELY(caller.Get() != nullptr && !VerifyAccess(
649        soa.Self(), receiver.Get(), declaring_class, constructor->GetAccessFlags(),
650        caller.Get()))) {
651      soa.Self()->ThrowNewExceptionF(
652          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
653          PrettyMethod(constructor).c_str(), PrettyClass(caller.Get()).c_str());
654      return nullptr;
655    }
656  }
657  // Ensure that we are initialized.
658  if (UNLIKELY(!declaring_class->IsInitialized())) {
659    if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(
660        soa.Self(), hs.NewHandle(declaring_class), true, true)) {
661      soa.Self()->AssertPendingException();
662      return nullptr;
663    }
664  }
665  // Invoke the constructor.
666  JValue result;
667  uint32_t args[1] = { static_cast<uint32_t>(reinterpret_cast<uintptr_t>(receiver.Get())) };
668  constructor->Invoke(soa.Self(), args, sizeof(args), &result, "V");
669  if (UNLIKELY(soa.Self()->IsExceptionPending())) {
670    return nullptr;
671  }
672  // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
673  return soa.AddLocalReference<jobject>(receiver.Get());
674}
675
676static JNINativeMethod gMethods[] = {
677  NATIVE_METHOD(Class, classForName,
678                "!(Ljava/lang/String;ZLjava/lang/ClassLoader;)Ljava/lang/Class;"),
679  NATIVE_METHOD(Class, getDeclaredAnnotation,
680                "!(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;"),
681  NATIVE_METHOD(Class, getDeclaredAnnotations, "!()[Ljava/lang/annotation/Annotation;"),
682  NATIVE_METHOD(Class, getDeclaredClasses, "!()[Ljava/lang/Class;"),
683  NATIVE_METHOD(Class, getDeclaredConstructorInternal,
684                "!([Ljava/lang/Class;)Ljava/lang/reflect/Constructor;"),
685  NATIVE_METHOD(Class, getDeclaredConstructorsInternal, "!(Z)[Ljava/lang/reflect/Constructor;"),
686  NATIVE_METHOD(Class, getDeclaredField, "!(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
687  NATIVE_METHOD(Class, getPublicFieldRecursive, "!(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
688  NATIVE_METHOD(Class, getDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
689  NATIVE_METHOD(Class, getDeclaredFieldsUnchecked, "!(Z)[Ljava/lang/reflect/Field;"),
690  NATIVE_METHOD(Class, getDeclaredMethodInternal,
691                "!(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;"),
692  NATIVE_METHOD(Class, getDeclaredMethodsUnchecked,
693                "!(Z)[Ljava/lang/reflect/Method;"),
694  NATIVE_METHOD(Class, getDeclaringClass, "!()Ljava/lang/Class;"),
695  NATIVE_METHOD(Class, getEnclosingClass, "!()Ljava/lang/Class;"),
696  NATIVE_METHOD(Class, getEnclosingConstructorNative, "!()Ljava/lang/reflect/Constructor;"),
697  NATIVE_METHOD(Class, getEnclosingMethodNative, "!()Ljava/lang/reflect/Method;"),
698  NATIVE_METHOD(Class, getInnerClassFlags, "!(I)I"),
699  NATIVE_METHOD(Class, getInnerClassName, "!()Ljava/lang/String;"),
700  NATIVE_METHOD(Class, getNameNative, "!()Ljava/lang/String;"),
701  NATIVE_METHOD(Class, getProxyInterfaces, "!()[Ljava/lang/Class;"),
702  NATIVE_METHOD(Class, getPublicDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
703  NATIVE_METHOD(Class, getSignatureAnnotation, "!()[Ljava/lang/String;"),
704  NATIVE_METHOD(Class, isAnonymousClass, "!()Z"),
705  NATIVE_METHOD(Class, isDeclaredAnnotationPresent, "!(Ljava/lang/Class;)Z"),
706  NATIVE_METHOD(Class, newInstance, "!()Ljava/lang/Object;"),
707};
708
709void register_java_lang_Class(JNIEnv* env) {
710  REGISTER_NATIVE_METHODS("java/lang/Class");
711}
712
713}  // namespace art
714