java_lang_Class.cc revision 1133db79350060158f99210c56f111c6dad43563 
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  auto* klass = DecodeClass(soa, javaThis);
326  auto* params = soa.Decode<mirror::ObjectArray<mirror::Class>*>(args);
327  StackHandleScope<1> hs(soa.Self());
328  auto* declared_constructor = klass->GetDeclaredConstructor(soa.Self(), hs.NewHandle(params));
329  if (declared_constructor != nullptr) {
330    return soa.AddLocalReference<jobject>(
331        mirror::Constructor::CreateFromArtMethod(soa.Self(), declared_constructor));
332  }
333  return nullptr;
334}
335
336static ALWAYS_INLINE inline bool MethodMatchesConstructor(ArtMethod* m, bool public_only)
337    SHARED_REQUIRES(Locks::mutator_lock_) {
338  DCHECK(m != nullptr);
339  return (!public_only || m->IsPublic()) && !m->IsStatic() && m->IsConstructor();
340}
341
342static jobjectArray Class_getDeclaredConstructorsInternal(
343    JNIEnv* env, jobject javaThis, jboolean publicOnly) {
344  ScopedFastNativeObjectAccess soa(env);
345  StackHandleScope<2> hs(soa.Self());
346  Handle<mirror::Class> h_klass = hs.NewHandle(DecodeClass(soa, javaThis));
347  size_t constructor_count = 0;
348  // Two pass approach for speed.
349  for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
350    constructor_count += MethodMatchesConstructor(&m, publicOnly != JNI_FALSE) ? 1u : 0u;
351  }
352  auto h_constructors = hs.NewHandle(mirror::ObjectArray<mirror::Constructor>::Alloc(
353      soa.Self(), mirror::Constructor::ArrayClass(), constructor_count));
354  if (UNLIKELY(h_constructors.Get() == nullptr)) {
355    soa.Self()->AssertPendingException();
356    return nullptr;
357  }
358  constructor_count = 0;
359  for (auto& m : h_klass->GetDirectMethods(sizeof(void*))) {
360    if (MethodMatchesConstructor(&m, publicOnly != JNI_FALSE)) {
361      auto* constructor = mirror::Constructor::CreateFromArtMethod(soa.Self(), &m);
362      if (UNLIKELY(constructor == nullptr)) {
363        soa.Self()->AssertPendingOOMException();
364        return nullptr;
365      }
366      h_constructors->SetWithoutChecks<false>(constructor_count++, constructor);
367    }
368  }
369  return soa.AddLocalReference<jobjectArray>(h_constructors.Get());
370}
371
372static jobject Class_getDeclaredMethodInternal(JNIEnv* env, jobject javaThis,
373                                               jobject name, jobjectArray args) {
374  ScopedFastNativeObjectAccess soa(env);
375  mirror::Method* result = mirror::Class::GetDeclaredMethodInternal(
376      soa.Self(),
377      DecodeClass(soa, javaThis),
378      soa.Decode<mirror::String*>(name),
379      soa.Decode<mirror::ObjectArray<mirror::Class>*>(args));
380  return soa.AddLocalReference<jobject>(result);
381}
382
383static jobjectArray Class_getDeclaredMethodsUnchecked(JNIEnv* env, jobject javaThis,
384                                                      jboolean publicOnly) {
385  ScopedFastNativeObjectAccess soa(env);
386  StackHandleScope<2> hs(soa.Self());
387  Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
388  size_t num_methods = 0;
389  for (auto& m : klass->GetDeclaredMethods(sizeof(void*))) {
390    auto modifiers = m.GetAccessFlags();
391    // Add non-constructor declared methods.
392    if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
393        (modifiers & kAccConstructor) == 0) {
394      ++num_methods;
395    }
396  }
397  auto ret = hs.NewHandle(mirror::ObjectArray<mirror::Method>::Alloc(
398      soa.Self(), mirror::Method::ArrayClass(), num_methods));
399  num_methods = 0;
400  for (auto& m : klass->GetDeclaredMethods(sizeof(void*))) {
401    auto modifiers = m.GetAccessFlags();
402    if ((publicOnly == JNI_FALSE || (modifiers & kAccPublic) != 0) &&
403        (modifiers & kAccConstructor) == 0) {
404      auto* method = mirror::Method::CreateFromArtMethod(soa.Self(), &m);
405      if (method == nullptr) {
406        soa.Self()->AssertPendingException();
407        return nullptr;
408      }
409      ret->SetWithoutChecks<false>(num_methods++, method);
410    }
411  }
412  return soa.AddLocalReference<jobjectArray>(ret.Get());
413}
414
415static jobject Class_getDeclaredAnnotation(JNIEnv* env, jobject javaThis, jclass annotationClass) {
416  ScopedFastNativeObjectAccess soa(env);
417  StackHandleScope<2> hs(soa.Self());
418  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
419
420  // Handle public contract to throw NPE if the "annotationClass" argument was null.
421  if (UNLIKELY(annotationClass == nullptr)) {
422    ThrowNullPointerException("annotationClass");
423    return nullptr;
424  }
425
426  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
427    return nullptr;
428  }
429  Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class*>(annotationClass)));
430  return soa.AddLocalReference<jobject>(
431      klass->GetDexFile().GetAnnotationForClass(klass, annotation_class));
432}
433
434static jobjectArray Class_getDeclaredAnnotations(JNIEnv* env, jobject javaThis) {
435  ScopedFastNativeObjectAccess soa(env);
436  StackHandleScope<1> hs(soa.Self());
437  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
438  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
439    // Return an empty array instead of a null pointer.
440    mirror::Class* annotation_array_class =
441        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_annotation_Annotation__array);
442    mirror::ObjectArray<mirror::Object>* empty_array =
443        mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), annotation_array_class, 0);
444    return soa.AddLocalReference<jobjectArray>(empty_array);
445  }
446  return soa.AddLocalReference<jobjectArray>(klass->GetDexFile().GetAnnotationsForClass(klass));
447}
448
449static jobjectArray Class_getDeclaredClasses(JNIEnv* env, jobject javaThis) {
450  ScopedFastNativeObjectAccess soa(env);
451  StackHandleScope<1> hs(soa.Self());
452  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
453  mirror::ObjectArray<mirror::Class>* classes = nullptr;
454  if (!klass->IsProxyClass() && klass->GetDexCache() != nullptr) {
455    classes = klass->GetDexFile().GetDeclaredClasses(klass);
456  }
457  if (classes == nullptr) {
458    // Return an empty array instead of a null pointer.
459    if (soa.Self()->IsExceptionPending()) {
460      // Pending exception from GetDeclaredClasses.
461      return nullptr;
462    }
463    mirror::Class* class_class = mirror::Class::GetJavaLangClass();
464    mirror::Class* class_array_class =
465        Runtime::Current()->GetClassLinker()->FindArrayClass(soa.Self(), &class_class);
466    if (class_array_class == nullptr) {
467      return nullptr;
468    }
469    mirror::ObjectArray<mirror::Class>* empty_array =
470        mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
471    return soa.AddLocalReference<jobjectArray>(empty_array);
472  }
473  return soa.AddLocalReference<jobjectArray>(classes);
474}
475
476static jclass Class_getEnclosingClass(JNIEnv* env, jobject javaThis) {
477  ScopedFastNativeObjectAccess soa(env);
478  StackHandleScope<1> hs(soa.Self());
479  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
480  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
481    return nullptr;
482  }
483  return soa.AddLocalReference<jclass>(klass->GetDexFile().GetEnclosingClass(klass));
484}
485
486static jobject Class_getEnclosingConstructorNative(JNIEnv* env, jobject javaThis) {
487  ScopedFastNativeObjectAccess soa(env);
488  StackHandleScope<1> hs(soa.Self());
489  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
490  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
491    return nullptr;
492  }
493  mirror::Object* method = klass->GetDexFile().GetEnclosingMethod(klass);
494  if (method != nullptr) {
495    if (method->GetClass() ==
496        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_reflect_Constructor)) {
497      return soa.AddLocalReference<jobject>(method);
498    }
499  }
500  return nullptr;
501}
502
503static jobject Class_getEnclosingMethodNative(JNIEnv* env, jobject javaThis) {
504  ScopedFastNativeObjectAccess soa(env);
505  StackHandleScope<1> hs(soa.Self());
506  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
507  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
508    return nullptr;
509  }
510  mirror::Object* method = klass->GetDexFile().GetEnclosingMethod(klass);
511  if (method != nullptr) {
512    if (method->GetClass() ==
513        soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_reflect_Method)) {
514      return soa.AddLocalReference<jobject>(method);
515    }
516  }
517  return nullptr;
518}
519
520static jint Class_getInnerClassFlags(JNIEnv* env, jobject javaThis, jint defaultValue) {
521  ScopedFastNativeObjectAccess soa(env);
522  StackHandleScope<1> hs(soa.Self());
523  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
524  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
525    return defaultValue;
526  }
527  uint32_t flags;
528  if (!klass->GetDexFile().GetInnerClassFlags(klass, &flags)) {
529    return defaultValue;
530  }
531  return flags;
532}
533
534static jstring Class_getInnerClassName(JNIEnv* env, jobject javaThis) {
535  ScopedFastNativeObjectAccess soa(env);
536  StackHandleScope<1> hs(soa.Self());
537  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
538  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
539    return nullptr;
540  }
541  mirror::String* class_name = nullptr;
542  if (!klass->GetDexFile().GetInnerClass(klass, &class_name)) {
543    return nullptr;
544  }
545  return soa.AddLocalReference<jstring>(class_name);
546}
547
548static jobjectArray Class_getSignatureAnnotation(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  return soa.AddLocalReference<jobjectArray>(
556      klass->GetDexFile().GetSignatureAnnotationForClass(klass));
557}
558
559static jboolean Class_isAnonymousClass(JNIEnv* env, jobject javaThis) {
560  ScopedFastNativeObjectAccess soa(env);
561  StackHandleScope<1> hs(soa.Self());
562  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
563  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
564    return false;
565  }
566  mirror::String* class_name = nullptr;
567  if (!klass->GetDexFile().GetInnerClass(klass, &class_name)) {
568    return false;
569  }
570  return class_name == nullptr;
571}
572
573static jboolean Class_isDeclaredAnnotationPresent(JNIEnv* env, jobject javaThis,
574                                                  jclass annotationType) {
575  ScopedFastNativeObjectAccess soa(env);
576  StackHandleScope<2> hs(soa.Self());
577  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
578  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
579    return false;
580  }
581  Handle<mirror::Class> annotation_class(hs.NewHandle(soa.Decode<mirror::Class*>(annotationType)));
582  return klass->GetDexFile().IsClassAnnotationPresent(klass, annotation_class);
583}
584
585static jclass Class_getDeclaringClass(JNIEnv* env, jobject javaThis) {
586  ScopedFastNativeObjectAccess soa(env);
587  StackHandleScope<1> hs(soa.Self());
588  Handle<mirror::Class> klass(hs.NewHandle(DecodeClass(soa, javaThis)));
589  if (klass->IsProxyClass() || klass->GetDexCache() == nullptr) {
590    return nullptr;
591  }
592  // Return null for anonymous classes.
593  if (Class_isAnonymousClass(env, javaThis)) {
594    return nullptr;
595  }
596  return soa.AddLocalReference<jclass>(klass->GetDexFile().GetDeclaringClass(klass));
597}
598
599static jobject Class_newInstance(JNIEnv* env, jobject javaThis) {
600  ScopedFastNativeObjectAccess soa(env);
601  StackHandleScope<4> hs(soa.Self());
602  Handle<mirror::Class> klass = hs.NewHandle(DecodeClass(soa, javaThis));
603  if (UNLIKELY(klass->GetPrimitiveType() != 0 || klass->IsInterface() || klass->IsArrayClass() ||
604               klass->IsAbstract())) {
605    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
606                                   "%s cannot be instantiated", PrettyClass(klass.Get()).c_str());
607    return nullptr;
608  }
609  auto caller = hs.NewHandle<mirror::Class>(nullptr);
610  // Verify that we can access the class.
611  if (!klass->IsPublic()) {
612    caller.Assign(GetCallingClass(soa.Self(), 1));
613    if (caller.Get() != nullptr && !caller->CanAccess(klass.Get())) {
614      soa.Self()->ThrowNewExceptionF(
615          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
616          PrettyClass(klass.Get()).c_str(), PrettyClass(caller.Get()).c_str());
617      return nullptr;
618    }
619  }
620  auto* constructor = klass->GetDeclaredConstructor(
621      soa.Self(),
622      ScopedNullHandle<mirror::ObjectArray<mirror::Class>>());
623  if (UNLIKELY(constructor == nullptr)) {
624    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
625                                   "%s has no zero argument constructor",
626                                   PrettyClass(klass.Get()).c_str());
627    return nullptr;
628  }
629  // Invoke the string allocator to return an empty string for the string class.
630  if (klass->IsStringClass()) {
631    gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
632    mirror::SetStringCountVisitor visitor(0);
633    mirror::Object* obj = mirror::String::Alloc<true>(soa.Self(), 0, allocator_type, visitor);
634    if (UNLIKELY(soa.Self()->IsExceptionPending())) {
635      return nullptr;
636    } else {
637      return soa.AddLocalReference<jobject>(obj);
638    }
639  }
640  auto receiver = hs.NewHandle(klass->AllocObject(soa.Self()));
641  if (UNLIKELY(receiver.Get() == nullptr)) {
642    soa.Self()->AssertPendingOOMException();
643    return nullptr;
644  }
645  // Verify that we can access the constructor.
646  auto* declaring_class = constructor->GetDeclaringClass();
647  if (!constructor->IsPublic()) {
648    if (caller.Get() == nullptr) {
649      caller.Assign(GetCallingClass(soa.Self(), 1));
650    }
651    if (UNLIKELY(caller.Get() != nullptr && !VerifyAccess(
652        soa.Self(), receiver.Get(), declaring_class, constructor->GetAccessFlags(),
653        caller.Get()))) {
654      soa.Self()->ThrowNewExceptionF(
655          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
656          PrettyMethod(constructor).c_str(), PrettyClass(caller.Get()).c_str());
657      return nullptr;
658    }
659  }
660  // Ensure that we are initialized.
661  if (UNLIKELY(!declaring_class->IsInitialized())) {
662    if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(
663        soa.Self(), hs.NewHandle(declaring_class), true, true)) {
664      soa.Self()->AssertPendingException();
665      return nullptr;
666    }
667  }
668  // Invoke the constructor.
669  JValue result;
670  uint32_t args[1] = { static_cast<uint32_t>(reinterpret_cast<uintptr_t>(receiver.Get())) };
671  constructor->Invoke(soa.Self(), args, sizeof(args), &result, "V");
672  if (UNLIKELY(soa.Self()->IsExceptionPending())) {
673    return nullptr;
674  }
675  // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
676  return soa.AddLocalReference<jobject>(receiver.Get());
677}
678
679static JNINativeMethod gMethods[] = {
680  NATIVE_METHOD(Class, classForName,
681                "!(Ljava/lang/String;ZLjava/lang/ClassLoader;)Ljava/lang/Class;"),
682  NATIVE_METHOD(Class, getDeclaredAnnotation,
683                "!(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;"),
684  NATIVE_METHOD(Class, getDeclaredAnnotations, "!()[Ljava/lang/annotation/Annotation;"),
685  NATIVE_METHOD(Class, getDeclaredClasses, "!()[Ljava/lang/Class;"),
686  NATIVE_METHOD(Class, getDeclaredConstructorInternal,
687                "!([Ljava/lang/Class;)Ljava/lang/reflect/Constructor;"),
688  NATIVE_METHOD(Class, getDeclaredConstructorsInternal, "!(Z)[Ljava/lang/reflect/Constructor;"),
689  NATIVE_METHOD(Class, getDeclaredField, "!(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
690  NATIVE_METHOD(Class, getPublicFieldRecursive, "!(Ljava/lang/String;)Ljava/lang/reflect/Field;"),
691  NATIVE_METHOD(Class, getDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
692  NATIVE_METHOD(Class, getDeclaredFieldsUnchecked, "!(Z)[Ljava/lang/reflect/Field;"),
693  NATIVE_METHOD(Class, getDeclaredMethodInternal,
694                "!(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;"),
695  NATIVE_METHOD(Class, getDeclaredMethodsUnchecked,
696                "!(Z)[Ljava/lang/reflect/Method;"),
697  NATIVE_METHOD(Class, getDeclaringClass, "!()Ljava/lang/Class;"),
698  NATIVE_METHOD(Class, getEnclosingClass, "!()Ljava/lang/Class;"),
699  NATIVE_METHOD(Class, getEnclosingConstructorNative, "!()Ljava/lang/reflect/Constructor;"),
700  NATIVE_METHOD(Class, getEnclosingMethodNative, "!()Ljava/lang/reflect/Method;"),
701  NATIVE_METHOD(Class, getInnerClassFlags, "!(I)I"),
702  NATIVE_METHOD(Class, getInnerClassName, "!()Ljava/lang/String;"),
703  NATIVE_METHOD(Class, getNameNative, "!()Ljava/lang/String;"),
704  NATIVE_METHOD(Class, getProxyInterfaces, "!()[Ljava/lang/Class;"),
705  NATIVE_METHOD(Class, getPublicDeclaredFields, "!()[Ljava/lang/reflect/Field;"),
706  NATIVE_METHOD(Class, getSignatureAnnotation, "!()[Ljava/lang/String;"),
707  NATIVE_METHOD(Class, isAnonymousClass, "!()Z"),
708  NATIVE_METHOD(Class, isDeclaredAnnotationPresent, "!(Ljava/lang/Class;)Z"),
709  NATIVE_METHOD(Class, newInstance, "!()Ljava/lang/Object;"),
710};
711
712void register_java_lang_Class(JNIEnv* env) {
713  REGISTER_NATIVE_METHODS("java/lang/Class");
714}
715
716}  // namespace art
717