java_lang_Class.cc revision 7ea4c09989b37351e6c17a10d35934812053a746 
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 "art_field-inl.h"
20#include "class_linker.h"
21#include "common_throws.h"
22#include "dex_file-inl.h"
23#include "jni_internal.h"
24#include "nth_caller_visitor.h"
25#include "mirror/class-inl.h"
26#include "mirror/class_loader.h"
27#include "mirror/field-inl.h"
28#include "mirror/method.h"
29#include "mirror/object-inl.h"
30#include "mirror/object_array-inl.h"
31#include "mirror/string-inl.h"
32#include "reflection.h"
33#include "scoped_thread_state_change.h"
34#include "scoped_fast_native_object_access.h"
35#include "ScopedLocalRef.h"
36#include "ScopedUtfChars.h"
37#include "utf.h"
38#include "well_known_classes.h"
39
40namespace art {
41
42ALWAYS_INLINE static inline mirror::Class* DecodeClass(
43    const ScopedFastNativeObjectAccess& soa, jobject java_class)
44    SHARED_REQUIRES(Locks::mutator_lock_) {
45  mirror::Class* c = soa.Decode<mirror::Class*>(java_class);
46  DCHECK(c != nullptr);
47  DCHECK(c->IsClass());
48  // TODO: we could EnsureInitialized here, rather than on every reflective get/set or invoke .
49  // For now, we conservatively preserve the old dalvik behavior. A quick "IsInitialized" check
50  // every time probably doesn't make much difference to reflection performance anyway.
51  return c;
52}
53
54// "name" is in "binary name" format, e.g. "dalvik.system.Debug$1".
55static jclass Class_classForName(JNIEnv* env, jclass, jstring javaName, jboolean initialize,
56                                 jobject javaLoader) {
57  ScopedFastNativeObjectAccess soa(env);
58  ScopedUtfChars name(env, javaName);
59  if (name.c_str() == nullptr) {
60    return nullptr;
61  }
62
63  // We need to validate and convert the name (from x.y.z to x/y/z).  This
64  // is especially handy for array types, since we want to avoid
65  // auto-generating bogus array classes.
66  if (!IsValidBinaryClassName(name.c_str())) {
67    soa.Self()->ThrowNewExceptionF("Ljava/lang/ClassNotFoundException;",
68                                   "Invalid name: %s", name.c_str());
69    return nullptr;
70  }
71
72  std::string descriptor(DotToDescriptor(name.c_str()));
73  StackHandleScope<2> hs(soa.Self());
74  Handle<mirror::ClassLoader> class_loader(hs.NewHandle(soa.Decode<mirror::ClassLoader*>(javaLoader)));
75  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
76  Handle<mirror::Class> c(
77      hs.NewHandle(class_linker->FindClass(soa.Self(), descriptor.c_str(), class_loader)));
78  if (c.Get() == nullptr) {
79    ScopedLocalRef<jthrowable> cause(env, env->ExceptionOccurred());
80    env->ExceptionClear();
81    jthrowable cnfe = reinterpret_cast<jthrowable>(env->NewObject(WellKnownClasses::java_lang_ClassNotFoundException,
82                                                                  WellKnownClasses::java_lang_ClassNotFoundException_init,
83                                                                  javaName, cause.get()));
84    if (cnfe != nullptr) {
85      // Make sure allocation didn't fail with an OOME.
86      env->Throw(cnfe);
87    }
88    return nullptr;
89  }
90  if (initialize) {
91    class_linker->EnsureInitialized(soa.Self(), c, true, true);
92  }
93  return soa.AddLocalReference<jclass>(c.Get());
94}
95
96static jstring Class_getNameNative(JNIEnv* env, jobject javaThis) {
97  ScopedFastNativeObjectAccess soa(env);
98  StackHandleScope<1> hs(soa.Self());
99  mirror::Class* const c = DecodeClass(soa, javaThis);
100  return soa.AddLocalReference<jstring>(mirror::Class::ComputeName(hs.NewHandle(c)));
101}
102
103static jobjectArray Class_getProxyInterfaces(JNIEnv* env, jobject javaThis) {
104  ScopedFastNativeObjectAccess soa(env);
105  mirror::Class* c = DecodeClass(soa, javaThis);
106  return soa.AddLocalReference<jobjectArray>(c->GetInterfaces()->Clone(soa.Self()));
107}
108
109static mirror::ObjectArray<mirror::Field>* GetDeclaredFields(
110    Thread* self, mirror::Class* klass, bool public_only, bool force_resolve)
111      SHARED_REQUIRES(Locks::mutator_lock_) {
112  StackHandleScope<1> hs(self);
113  IterationRange<StrideIterator<ArtField>> ifields = klass->GetIFields();
114  IterationRange<StrideIterator<ArtField>> sfields = klass->GetSFields();
115  size_t array_size = klass->NumInstanceFields() + klass->NumStaticFields();
116  if (public_only) {
117    // Lets go subtract all the non public fields.
118    for (ArtField& field : ifields) {
119      if (!field.IsPublic()) {
120        --array_size;
121      }
122    }
123    for (ArtField& field : sfields) {
124      if (!field.IsPublic()) {
125        --array_size;
126      }
127    }
128  }
129  size_t array_idx = 0;
130  auto object_array = hs.NewHandle(mirror::ObjectArray<mirror::Field>::Alloc(
131      self, mirror::Field::ArrayClass(), array_size));
132  if (object_array.Get() == nullptr) {
133    return nullptr;
134  }
135  for (ArtField& field : ifields) {
136    if (!public_only || field.IsPublic()) {
137      auto* reflect_field = mirror::Field::CreateFromArtField(self, &field, force_resolve);
138      if (reflect_field == nullptr) {
139        if (kIsDebugBuild) {
140          self->AssertPendingException();
141        }
142        // Maybe null due to OOME or type resolving exception.
143        return nullptr;
144      }
145      object_array->SetWithoutChecks<false>(array_idx++, reflect_field);
146    }
147  }
148  for (ArtField& field : sfields) {
149    if (!public_only || field.IsPublic()) {
150      auto* reflect_field = mirror::Field::CreateFromArtField(self, &field, force_resolve);
151      if (reflect_field == nullptr) {
152        if (kIsDebugBuild) {
153          self->AssertPendingException();
154        }
155        return nullptr;
156      }
157      object_array->SetWithoutChecks<false>(array_idx++, reflect_field);
158    }
159  }
160  DCHECK_EQ(array_idx, array_size);
161  return object_array.Get();
162}
163
164static jobjectArray Class_getDeclaredFieldsUnchecked(JNIEnv* env, jobject javaThis,
165                                                     jboolean publicOnly) {
166  ScopedFastNativeObjectAccess soa(env);
167  return soa.AddLocalReference<jobjectArray>(
168      GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), publicOnly != JNI_FALSE, false));
169}
170
171static jobjectArray Class_getDeclaredFields(JNIEnv* env, jobject javaThis) {
172  ScopedFastNativeObjectAccess soa(env);
173  return soa.AddLocalReference<jobjectArray>(
174      GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), false, true));
175}
176
177static jobjectArray Class_getPublicDeclaredFields(JNIEnv* env, jobject javaThis) {
178  ScopedFastNativeObjectAccess soa(env);
179  return soa.AddLocalReference<jobjectArray>(
180      GetDeclaredFields(soa.Self(), DecodeClass(soa, javaThis), true, true));
181}
182
183// Performs a binary search through an array of fields, TODO: Is this fast enough if we don't use
184// the dex cache for lookups? I think CompareModifiedUtf8ToUtf16AsCodePointValues should be fairly
185// fast.
186ALWAYS_INLINE static inline ArtField* FindFieldByName(
187    Thread* self ATTRIBUTE_UNUSED, mirror::String* name, LengthPrefixedArray<ArtField>* fields)
188    SHARED_REQUIRES(Locks::mutator_lock_) {
189  if (fields == nullptr) {
190    return nullptr;
191  }
192  size_t low = 0;
193  size_t high = fields->size();
194  const uint16_t* const data = name->GetValue();
195  const size_t length = name->GetLength();
196  while (low < high) {
197    auto mid = (low + high) / 2;
198    ArtField& field = fields->At(mid);
199    int result = CompareModifiedUtf8ToUtf16AsCodePointValues(field.GetName(), data, length);
200    // Alternate approach, only a few % faster at the cost of more allocations.
201    // int result = field->GetStringName(self, true)->CompareTo(name);
202    if (result < 0) {
203      low = mid + 1;
204    } else if (result > 0) {
205      high = mid;
206    } else {
207      return &field;
208    }
209  }
210  if (kIsDebugBuild) {
211    for (ArtField& field : MakeIterationRangeFromLengthPrefixedArray(fields)) {
212      CHECK_NE(field.GetName(), name->ToModifiedUtf8());
213    }
214  }
215  return nullptr;
216}
217
218ALWAYS_INLINE static inline mirror::Field* GetDeclaredField(
219    Thread* self, mirror::Class* c, mirror::String* name)
220    SHARED_REQUIRES(Locks::mutator_lock_) {
221  ArtField* art_field = FindFieldByName(self, name, c->GetIFieldsPtr());
222  if (art_field != nullptr) {
223    return mirror::Field::CreateFromArtField(self, art_field, true);
224  }
225  art_field = FindFieldByName(self, name, c->GetSFieldsPtr());
226  if (art_field != nullptr) {
227    return mirror::Field::CreateFromArtField(self, art_field, true);
228  }
229  return nullptr;
230}
231
232static mirror::Field* GetPublicFieldRecursive(
233    Thread* self, mirror::Class* clazz, mirror::String* name)
234    SHARED_REQUIRES(Locks::mutator_lock_) {
235  DCHECK(clazz != nullptr);
236  DCHECK(name != nullptr);
237  DCHECK(self != nullptr);
238
239  StackHandleScope<1> hs(self);
240  MutableHandle<mirror::Class> h_clazz(hs.NewHandle(clazz));
241
242  // We search the current class, its direct interfaces then its superclass.
243  while (h_clazz.Get() != nullptr) {
244    mirror::Field* result = GetDeclaredField(self, h_clazz.Get(), name);
245    if ((result != nullptr) && (result->GetAccessFlags() & kAccPublic)) {
246      return result;
247    } else if (UNLIKELY(self->IsExceptionPending())) {
248      // Something went wrong. Bail out.
249      return nullptr;
250    }
251
252    uint32_t num_direct_interfaces = h_clazz->NumDirectInterfaces();
253    for (uint32_t i = 0; i < num_direct_interfaces; i++) {
254      mirror::Class *iface = mirror::Class::GetDirectInterface(self, h_clazz, i);
255      if (UNLIKELY(iface == nullptr)) {
256        self->AssertPendingException();
257        return nullptr;
258      }
259      result = GetPublicFieldRecursive(self, iface, name);
260      if (result != nullptr) {
261        DCHECK(result->GetAccessFlags() & kAccPublic);
262        return result;
263      } else if (UNLIKELY(self->IsExceptionPending())) {
264        // Something went wrong. Bail out.
265        return nullptr;
266      }
267    }
268
269    // We don't try the superclass if we are an interface.
270    if (h_clazz->IsInterface()) {
271      break;
272    }
273
274    // Get the next class.
275    h_clazz.Assign(h_clazz->GetSuperClass());
276  }
277  return nullptr;
278}
279
280static jobject Class_getPublicFieldRecursive(JNIEnv* env, jobject javaThis, jstring name) {
281  ScopedFastNativeObjectAccess soa(env);
282  auto* name_string = soa.Decode<mirror::String*>(name);
283  if (UNLIKELY(name_string == nullptr)) {
284    ThrowNullPointerException("name == null");
285    return nullptr;
286  }
287  return soa.AddLocalReference<jobject>(
288      GetPublicFieldRecursive(soa.Self(), DecodeClass(soa, javaThis), name_string));
289}
290
291static jobject Class_getDeclaredField(JNIEnv* env, jobject javaThis, jstring name) {
292  ScopedFastNativeObjectAccess soa(env);
293  auto* name_string = soa.Decode<mirror::String*>(name);
294  if (name_string == nullptr) {
295    ThrowNullPointerException("name == null");
296    return nullptr;
297  }
298  auto* klass = DecodeClass(soa, javaThis);
299  mirror::Field* result = GetDeclaredField(soa.Self(), klass, name_string);
300  if (result == nullptr) {
301    std::string name_str = name_string->ToModifiedUtf8();
302    if (name_str == "value" && klass->IsStringClass()) {
303      // We log the error for this specific case, as the user might just swallow the exception.
304      // This helps diagnose crashes when applications rely on the String#value field being
305      // there.
306      LOG(ERROR) << "The String#value field is not present on Android versions >= 6.0";
307    }
308    // We may have a pending exception if we failed to resolve.
309    if (!soa.Self()->IsExceptionPending()) {
310      ThrowNoSuchFieldException(DecodeClass(soa, javaThis), name_str.c_str());
311    }
312    return nullptr;
313  }
314  return soa.AddLocalReference<jobject>(result);
315}
316
317static jobject Class_getDeclaredConstructorInternal(
318    JNIEnv* env, jobject javaThis, jobjectArray args) {
319  ScopedFastNativeObjectAccess soa(env);
320  auto* klass = DecodeClass(soa, javaThis);
321  auto* params = soa.Decode<mirror::ObjectArray<mirror::Class>*>(args);
322  StackHandleScope<1> hs(soa.Self());
323  auto* declared_constructor = klass->GetDeclaredConstructor(soa.Self(), hs.NewHandle(params));
324  if (declared_constructor != nullptr) {
325    return soa.AddLocalReference<jobject>(
326        mirror::Constructor::CreateFromArtMethod(soa.Self(), declared_constructor));
327  }
328  return nullptr;
329}
330
331static ALWAYS_INLINE inline bool MethodMatchesConstructor(ArtMethod* m, bool public_only)
332    SHARED_REQUIRES(Locks::mutator_lock_) {
333  DCHECK(m != nullptr);
334  return (!public_only || m->IsPublic()) && !m->IsStatic() && m->IsConstructor();
335}
336
337static jobjectArray Class_getDeclaredConstructorsInternal(
338    JNIEnv* env, jobject javaThis, jboolean publicOnly) {
339  ScopedFastNativeObjectAccess soa(env);
340  StackHandleScope<2> hs(soa.Self());
341  Handle<mirror::Class> h_klass = hs.NewHandle(DecodeClass(soa, javaThis));
342  size_t constructor_count = 0;
343  // Two pass approach for speed.
344  for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
345    constructor_count += MethodMatchesConstructor(&m, publicOnly != JNI_FALSE) ? 1u : 0u;
346  }
347  auto h_constructors = hs.NewHandle(mirror::ObjectArray<mirror::Constructor>::Alloc(
348      soa.Self(), mirror::Constructor::ArrayClass(), constructor_count));
349  if (UNLIKELY(h_constructors.Get() == nullptr)) {
350    soa.Self()->AssertPendingException();
351    return nullptr;
352  }
353  constructor_count = 0;
354  for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
355    if (MethodMatchesConstructor(&m, publicOnly != JNI_FALSE)) {
356      auto* constructor = mirror::Constructor::CreateFromArtMethod(soa.Self(), &m);
357      if (UNLIKELY(constructor == nullptr)) {
358        soa.Self()->AssertPendingOOMException();
359        return nullptr;
360      }
361      h_constructors->SetWithoutChecks<false>(constructor_count++, constructor);
362    }
363  }
364  return soa.AddLocalReference<jobjectArray>(h_constructors.Get());
365}
366
367static jobject Class_getDeclaredMethodInternal(JNIEnv* env, jobject javaThis,
368                                               jobject name, jobjectArray args) {
369  // Covariant return types permit the class to define multiple
370  // methods with the same name and parameter types. Prefer to
371  // return a non-synthetic method in such situations. We may
372  // still return a synthetic method to handle situations like
373  // escalated visibility. We never return miranda methods that
374  // were synthesized by the runtime.
375  constexpr uint32_t kSkipModifiers = kAccMiranda | kAccSynthetic;
376  ScopedFastNativeObjectAccess soa(env);
377  StackHandleScope<3> hs(soa.Self());
378  auto h_method_name = hs.NewHandle(soa.Decode<mirror::String*>(name));
379  if (UNLIKELY(h_method_name.Get() == nullptr)) {
380    ThrowNullPointerException("name == null");
381    return nullptr;
382  }
383  auto h_args = hs.NewHandle(soa.Decode<mirror::ObjectArray<mirror::Class>*>(args));
384  Handle<mirror::Class> h_klass = hs.NewHandle(DecodeClass(soa, javaThis));
385  ArtMethod* result = nullptr;
386  for (auto& m : h_klass->GetVirtualMethods(sizeof(void*))) {
387    auto* np_method = m.GetInterfaceMethodIfProxy(sizeof(void*));
388    // May cause thread suspension.
389    mirror::String* np_name = np_method->GetNameAsString(soa.Self());
390    if (!np_name->Equals(h_method_name.Get()) || !np_method->EqualParameters(h_args)) {
391      if (UNLIKELY(soa.Self()->IsExceptionPending())) {
392        return nullptr;
393      }
394      continue;
395    }
396    auto modifiers = m.GetAccessFlags();
397    if ((modifiers & kSkipModifiers) == 0) {
398      return soa.AddLocalReference<jobject>(mirror::Method::CreateFromArtMethod(soa.Self(), &m));
399    }
400    if ((modifiers & kAccMiranda) == 0) {
401      result = &m;  // Remember as potential result if it's not a miranda method.
402    }
403  }
404  if (result == nullptr) {
405    for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
406      auto modifiers = m.GetAccessFlags();
407      if ((modifiers & kAccConstructor) != 0) {
408        continue;
409      }
410      auto* np_method = m.GetInterfaceMethodIfProxy(sizeof(void*));
411      // May cause thread suspension.
412      mirror::String* np_name = np_method->GetNameAsString(soa.Self());
413      if (np_name == nullptr) {
414        soa.Self()->AssertPendingException();
415        return nullptr;
416      }
417      if (!np_name->Equals(h_method_name.Get()) || !np_method->EqualParameters(h_args)) {
418        if (UNLIKELY(soa.Self()->IsExceptionPending())) {
419          return nullptr;
420        }
421        continue;
422      }
423      if ((modifiers & kSkipModifiers) == 0) {
424        return soa.AddLocalReference<jobject>(mirror::Method::CreateFromArtMethod(soa.Self(), &m));
425      }
426      // Direct methods cannot be miranda methods, so this potential result must be synthetic.
427      result = &m;
428    }
429  }
430  return result != nullptr ?
431      soa.AddLocalReference<jobject>(mirror::Method::CreateFromArtMethod(soa.Self(), result)) :
432      nullptr;
433}
434
435static jobjectArray Class_getDeclaredMethodsUnchecked(JNIEnv* env, jobject javaThis,
436                                                      jboolean publicOnly) {
437  ScopedFastNativeObjectAccess soa(env);
438  StackHandleScope<2> hs(soa.Self());
439  Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
440  size_t num_methods = 0;
441  for (auto& m : klass->GetDeclaredMethods(sizeof(void*))) {
442    auto modifiers = m.GetAccessFlags();
443    // Add non-constructor declared methods.
444    if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
445        (modifiers & kAccConstructor) == 0) {
446      ++num_methods;
447    }
448  }
449  auto ret = hs.NewHandle(mirror::ObjectArray<mirror::Method>::Alloc(
450      soa.Self(), mirror::Method::ArrayClass(), num_methods));
451  num_methods = 0;
452  for (auto& m : klass->GetDeclaredMethods(sizeof(void*))) {
453    auto modifiers = m.GetAccessFlags();
454    if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
455        (modifiers & kAccConstructor) == 0) {
456      auto* method = mirror::Method::CreateFromArtMethod(soa.Self(), &m);
457      if (method == nullptr) {
458        soa.Self()->AssertPendingException();
459        return nullptr;
460      }
461      ret->SetWithoutChecks<false>(num_methods++, method);
462    }
463  }
464  return soa.AddLocalReference<jobjectArray>(ret.Get());
465}
466
467static jobject Class_getDeclaredAnnotation(JNIEnv* env, jobject javaThis, jclass annotationType) {
468  ScopedFastNativeObjectAccess soa(env);
469  StackHandleScope<2> hs(soa.Self());
470  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
471  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
472    return nullptr;
473  }
474  Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class*>(annotationType)));
475  return soa.AddLocalReference<jobject>(
476      klass->GetDexFile().GetAnnotationForClass(klass, annotation_class));
477}
478
479static jobjectArray Class_getDeclaredAnnotations(JNIEnv* env, jobject javaThis) {
480  ScopedFastNativeObjectAccess soa(env);
481  StackHandleScope<1> hs(soa.Self());
482  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
483  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
484    // Return an empty array instead of a null pointer.
485    mirror::Class* annotation_array_class =
486        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_annotation_Annotation__array);
487    mirror::ObjectArray<mirror::Object>* empty_array =
488        mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), annotation_array_class, 0);
489    return soa.AddLocalReference<jobjectArray>(empty_array);
490  }
491  return soa.AddLocalReference<jobjectArray>(klass->GetDexFile().GetAnnotationsForClass(klass));
492}
493
494static jobjectArray Class_getDeclaredClasses(JNIEnv* env, jobject javaThis) {
495  ScopedFastNativeObjectAccess soa(env);
496  StackHandleScope<1> hs(soa.Self());
497  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
498  mirror::ObjectArray<mirror::Class>* classes = nullptr;
499  if (!klass->IsProxyClass() && klass->GetDexCache() != nullptr) {
500    classes = klass->GetDexFile().GetDeclaredClasses(klass);
501  }
502  if (classes == nullptr) {
503    // Return an empty array instead of a null pointer.
504    if (soa.Self()->IsExceptionPending()) {
505      // Pending exception from GetDeclaredClasses.
506      return nullptr;
507    }
508    mirror::Class* class_class = mirror::Class::GetJavaLangClass();
509    mirror::Class* class_array_class =
510        Runtime::Current()->GetClassLinker()->FindArrayClass(soa.Self(), &class_class);
511    if (class_array_class == nullptr) {
512      return nullptr;
513    }
514    mirror::ObjectArray<mirror::Class>* empty_array =
515        mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
516    return soa.AddLocalReference<jobjectArray>(empty_array);
517  }
518  return soa.AddLocalReference<jobjectArray>(classes);
519}
520
521static jclass Class_getEnclosingClass(JNIEnv* env, jobject javaThis) {
522  ScopedFastNativeObjectAccess soa(env);
523  StackHandleScope<1> hs(soa.Self());
524  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
525  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
526    return nullptr;
527  }
528  return soa.AddLocalReference<jclass>(klass->GetDexFile().GetEnclosingClass(klass));
529}
530
531static jobject Class_getEnclosingConstructorNative(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  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
536    return nullptr;
537  }
538  mirror::Object* method = klass->GetDexFile().GetEnclosingMethod(klass);
539  if (method != nullptr) {
540    if (method->GetClass() ==
541        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_reflect_Constructor)) {
542      return soa.AddLocalReference<jobject>(method);
543    }
544  }
545  return nullptr;
546}
547
548static jobject Class_getEnclosingMethodNative(JNIEnv* env, jobject javaThis) {
549  ScopedFastNativeObjectAccess soa(env);
550  StackHandleScope<1> hs(soa.Self());
551  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
552  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
553    return nullptr;
554  }
555  mirror::Object* method = klass->GetDexFile().GetEnclosingMethod(klass);
556  if (method != nullptr) {
557    if (method->GetClass() ==
558        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_reflect_Method)) {
559      return soa.AddLocalReference<jobject>(method);
560    }
561  }
562  return nullptr;
563}
564
565static jint Class_getInnerClassFlags(JNIEnv* env, jobject javaThis, jint defaultValue) {
566  ScopedFastNativeObjectAccess soa(env);
567  StackHandleScope<1> hs(soa.Self());
568  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
569  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
570    return defaultValue;
571  }
572  uint32_t flags;
573  if (!klass->GetDexFile().GetInnerClassFlags(klass, &flags)) {
574    return defaultValue;
575  }
576  return flags;
577}
578
579static jstring Class_getInnerClassName(JNIEnv* env, jobject javaThis) {
580  ScopedFastNativeObjectAccess soa(env);
581  StackHandleScope<1> hs(soa.Self());
582  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
583  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
584    return nullptr;
585  }
586  mirror::String* class_name = nullptr;
587  if (!klass->GetDexFile().GetInnerClass(klass, &class_name)) {
588    return nullptr;
589  }
590  return soa.AddLocalReference<jstring>(class_name);
591}
592
593static jboolean Class_isAnonymousClass(JNIEnv* env, jobject javaThis) {
594  ScopedFastNativeObjectAccess soa(env);
595  StackHandleScope<1> hs(soa.Self());
596  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
597  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
598    return false;
599  }
600  mirror::String* class_name = nullptr;
601  if (!klass->GetDexFile().GetInnerClass(klass, &class_name)) {
602    return false;
603  }
604  return class_name == nullptr;
605}
606
607static jboolean Class_isDeclaredAnnotationPresent(JNIEnv* env, jobject javaThis,
608                                                  jclass annotationType) {
609  ScopedFastNativeObjectAccess soa(env);
610  StackHandleScope<2> hs(soa.Self());
611  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
612  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
613    return false;
614  }
615  Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class*>(annotationType)));
616  return klass->GetDexFile().IsClassAnnotationPresent(klass, annotation_class);
617}
618
619static jclass Class_getDeclaringClass(JNIEnv* env, jobject javaThis) {
620  ScopedFastNativeObjectAccess soa(env);
621  StackHandleScope<1> hs(soa.Self());
622  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
623  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
624    return nullptr;
625  }
626  // Return null for anonymous classes.
627  if (Class_isAnonymousClass(env, javaThis)) {
628    return nullptr;
629  }
630  return soa.AddLocalReference<jclass>(klass->GetDexFile().GetDeclaringClass(klass));
631}
632
633static jobject Class_newInstance(JNIEnv* env, jobject javaThis) {
634  ScopedFastNativeObjectAccess soa(env);
635  StackHandleScope<4> hs(soa.Self());
636  Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
637  if (UNLIKELY(klass->GetPrimitiveType() != 0 || klass->IsInterface() || klass->IsArrayClass() ||
638               klass->IsAbstract())) {
639    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
640                                   "%s cannot be instantiated", PrettyClass(klass.Get()).c_str());
641    return nullptr;
642  }
643  auto caller = hs.NewHandle<mirror::Class>(nullptr);
644  // Verify that we can access the class.
645  if (!klass->IsPublic()) {
646    caller.Assign(GetCallingClass(soa.Self(), 1));
647    if (caller.Get() != nullptr && !caller->CanAccess(klass.Get())) {
648      soa.Self()->ThrowNewExceptionF(
649          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
650          PrettyClass(klass.Get()).c_str(), PrettyClass(caller.Get()).c_str());
651      return nullptr;
652    }
653  }
654  auto* constructor = klass->GetDeclaredConstructor(
655      soa.Self(),
656      ScopedNullHandle<mirror::ObjectArray<mirror::Class>>());
657  if (UNLIKELY(constructor == nullptr)) {
658    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
659                                   "%s has no zero argument constructor",
660                                   PrettyClass(klass.Get()).c_str());
661    return nullptr;
662  }
663  // Invoke the string allocator to return an empty string for the string class.
664  if (klass->IsStringClass()) {
665    gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
666    mirror::SetStringCountVisitor visitor(0);
667    mirror::Object* obj = mirror::String::Alloc<true>(soa.Self(), 0, allocator_type, visitor);
668    if (UNLIKELY(soa.Self()->IsExceptionPending())) {
669      return nullptr;
670    } else {
671      return soa.AddLocalReference<jobject>(obj);
672    }
673  }
674  auto receiver = hs.NewHandle(klass->AllocObject(soa.Self()));
675  if (UNLIKELY(receiver.Get() == nullptr)) {
676    soa.Self()->AssertPendingOOMException();
677    return nullptr;
678  }
679  // Verify that we can access the constructor.
680  auto* declaring_class = constructor->GetDeclaringClass();
681  if (!constructor->IsPublic()) {
682    if (caller.Get() == nullptr) {
683      caller.Assign(GetCallingClass(soa.Self(), 1));
684    }
685    if (UNLIKELY(caller.Get() != nullptr && !VerifyAccess(
686        soa.Self(), receiver.Get(), declaring_class, constructor->GetAccessFlags(),
687        caller.Get()))) {
688      soa.Self()->ThrowNewExceptionF(
689          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
690          PrettyMethod(constructor).c_str(), PrettyClass(caller.Get()).c_str());
691      return nullptr;
692    }
693  }
694  // Ensure that we are initialized.
695  if (UNLIKELY(!declaring_class->IsInitialized())) {
696    if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(
697        soa.Self(), hs.NewHandle(declaring_class), true, true)) {
698      soa.Self()->AssertPendingException();
699      return nullptr;
700    }
701  }
702  // Invoke the constructor.
703  JValue result;
704  uint32_t args[1] = { static_cast<uint32_t>(reinterpret_cast<uintptr_t>(receiver.Get())) };
705  constructor->Invoke(soa.Self(), args, sizeof(args), &result, "V");
706  if (UNLIKELY(soa.Self()->IsExceptionPending())) {
707    return nullptr;
708  }
709  // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
710  return soa.AddLocalReference<jobject>(receiver.Get());
711}
712
713static JNINativeMethod gMethods[] = {
714  NATIVE_METHOD(Class, classForName,
715                "!(Ljava/lang/String;ZLjava/lang/ClassLoader;)Ljava/lang/Class;"),
716  NATIVE_METHOD(Class, getDeclaredAnnotation,
717                "!(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;"),
718  NATIVE_METHOD(Class, getDeclaredAnnotations, "!()[Ljava/lang/annotation/Annotation;"),
719  NATIVE_METHOD(Class, getDeclaredClasses, "!()[Ljava/lang/Class;"),
720  NATIVE_METHOD(Class, getDeclaredConstructorInternal,
721                "!([Ljava/lang/Class;)Ljava/lang/reflect/Constructor;"),
722  NATIVE_METHOD(Class, getDeclaredConstructorsInternal, "!(Z)[Ljava/lang/reflect/Constructor;"),
723  NATIVE_METHOD(Class, getDeclaredField, "!(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
724  NATIVE_METHOD(Class, getPublicFieldRecursive, "!(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
725  NATIVE_METHOD(Class, getDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
726  NATIVE_METHOD(Class, getDeclaredFieldsUnchecked, "!(Z)[Ljava/lang/reflect/Field;"),
727  NATIVE_METHOD(Class, getDeclaredMethodInternal,
728                "!(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;"),
729  NATIVE_METHOD(Class, getDeclaredMethodsUnchecked,
730                "!(Z)[Ljava/lang/reflect/Method;"),
731  NATIVE_METHOD(Class, getDeclaringClass, "!()Ljava/lang/Class;"),
732  NATIVE_METHOD(Class, getEnclosingClass, "!()Ljava/lang/Class;"),
733  NATIVE_METHOD(Class, getEnclosingConstructorNative, "!()Ljava/lang/reflect/Constructor;"),
734  NATIVE_METHOD(Class, getEnclosingMethodNative, "!()Ljava/lang/reflect/Method;"),
735  NATIVE_METHOD(Class, getInnerClassFlags, "!(I)I"),
736  NATIVE_METHOD(Class, getInnerClassName, "!()Ljava/lang/String;"),
737  NATIVE_METHOD(Class, getNameNative, "!()Ljava/lang/String;"),
738  NATIVE_METHOD(Class, getProxyInterfaces, "!()[Ljava/lang/Class;"),
739  NATIVE_METHOD(Class, getPublicDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
740  NATIVE_METHOD(Class, isAnonymousClass, "!()Z"),
741  NATIVE_METHOD(Class, isDeclaredAnnotationPresent, "!(Ljava/lang/Class;)Z"),
742  NATIVE_METHOD(Class, newInstance, "!()Ljava/lang/Object;"),
743};
744
745void register_java_lang_Class(JNIEnv* env) {
746  REGISTER_NATIVE_METHODS("java/lang/Class");
747}
748
749}  // namespace art
750