reflection.cc revision 76433275dbe39e5ced1c223b006d1b900b1937f6 
1/*
2 * Copyright (C) 2011 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 "reflection-inl.h"
18
19#include "class_linker.h"
20#include "common_throws.h"
21#include "dex_file-inl.h"
22#include "jni_internal.h"
23#include "method_helper-inl.h"
24#include "mirror/art_field-inl.h"
25#include "mirror/art_method-inl.h"
26#include "mirror/class-inl.h"
27#include "mirror/class.h"
28#include "mirror/object_array-inl.h"
29#include "mirror/object_array.h"
30#include "nth_caller_visitor.h"
31#include "scoped_thread_state_change.h"
32#include "stack.h"
33#include "well_known_classes.h"
34
35namespace art {
36
37class ArgArray {
38 public:
39  explicit ArgArray(const char* shorty, uint32_t shorty_len)
40      : shorty_(shorty), shorty_len_(shorty_len), num_bytes_(0) {
41    size_t num_slots = shorty_len + 1;  // +1 in case of receiver.
42    if (LIKELY((num_slots * 2) < kSmallArgArraySize)) {
43      // We can trivially use the small arg array.
44      arg_array_ = small_arg_array_;
45    } else {
46      // Analyze shorty to see if we need the large arg array.
47      for (size_t i = 1; i < shorty_len; ++i) {
48        char c = shorty[i];
49        if (c == 'J' || c == 'D') {
50          num_slots++;
51        }
52      }
53      if (num_slots <= kSmallArgArraySize) {
54        arg_array_ = small_arg_array_;
55      } else {
56        large_arg_array_.reset(new uint32_t[num_slots]);
57        arg_array_ = large_arg_array_.get();
58      }
59    }
60  }
61
62  uint32_t* GetArray() {
63    return arg_array_;
64  }
65
66  uint32_t GetNumBytes() {
67    return num_bytes_;
68  }
69
70  void Append(uint32_t value) {
71    arg_array_[num_bytes_ / 4] = value;
72    num_bytes_ += 4;
73  }
74
75  void Append(mirror::Object* obj) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
76    Append(StackReference<mirror::Object>::FromMirrorPtr(obj).AsVRegValue());
77  }
78
79  void AppendWide(uint64_t value) {
80    // For ARM and MIPS portable, align wide values to 8 bytes (ArgArray starts at offset of 4).
81#if defined(ART_USE_PORTABLE_COMPILER) && (defined(__arm__) || defined(__mips__))
82    if (num_bytes_ % 8 == 0) {
83      num_bytes_ += 4;
84    }
85#endif
86    arg_array_[num_bytes_ / 4] = value;
87    arg_array_[(num_bytes_ / 4) + 1] = value >> 32;
88    num_bytes_ += 8;
89  }
90
91  void AppendFloat(float value) {
92    jvalue jv;
93    jv.f = value;
94    Append(jv.i);
95  }
96
97  void AppendDouble(double value) {
98    jvalue jv;
99    jv.d = value;
100    AppendWide(jv.j);
101  }
102
103  void BuildArgArrayFromVarArgs(const ScopedObjectAccessAlreadyRunnable& soa,
104                                mirror::Object* receiver, va_list ap)
105      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
106    // Set receiver if non-null (method is not static)
107    if (receiver != nullptr) {
108      Append(receiver);
109    }
110    for (size_t i = 1; i < shorty_len_; ++i) {
111      switch (shorty_[i]) {
112        case 'Z':
113        case 'B':
114        case 'C':
115        case 'S':
116        case 'I':
117          Append(va_arg(ap, jint));
118          break;
119        case 'F':
120          AppendFloat(va_arg(ap, jdouble));
121          break;
122        case 'L':
123          Append(soa.Decode<mirror::Object*>(va_arg(ap, jobject)));
124          break;
125        case 'D':
126          AppendDouble(va_arg(ap, jdouble));
127          break;
128        case 'J':
129          AppendWide(va_arg(ap, jlong));
130          break;
131#ifndef NDEBUG
132        default:
133          LOG(FATAL) << "Unexpected shorty character: " << shorty_[i];
134#endif
135      }
136    }
137  }
138
139  void BuildArgArrayFromJValues(const ScopedObjectAccessAlreadyRunnable& soa,
140                                mirror::Object* receiver, jvalue* args)
141      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
142    // Set receiver if non-null (method is not static)
143    if (receiver != nullptr) {
144      Append(receiver);
145    }
146    for (size_t i = 1, args_offset = 0; i < shorty_len_; ++i, ++args_offset) {
147      switch (shorty_[i]) {
148        case 'Z':
149          Append(args[args_offset].z);
150          break;
151        case 'B':
152          Append(args[args_offset].b);
153          break;
154        case 'C':
155          Append(args[args_offset].c);
156          break;
157        case 'S':
158          Append(args[args_offset].s);
159          break;
160        case 'I':
161        case 'F':
162          Append(args[args_offset].i);
163          break;
164        case 'L':
165          Append(soa.Decode<mirror::Object*>(args[args_offset].l));
166          break;
167        case 'D':
168        case 'J':
169          AppendWide(args[args_offset].j);
170          break;
171#ifndef NDEBUG
172        default:
173          LOG(FATAL) << "Unexpected shorty character: " << shorty_[i];
174#endif
175      }
176    }
177  }
178
179  void BuildArgArrayFromFrame(ShadowFrame* shadow_frame, uint32_t arg_offset)
180      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
181    // Set receiver if non-null (method is not static)
182    size_t cur_arg = arg_offset;
183    if (!shadow_frame->GetMethod()->IsStatic()) {
184      Append(shadow_frame->GetVReg(cur_arg));
185      cur_arg++;
186    }
187    for (size_t i = 1; i < shorty_len_; ++i) {
188      switch (shorty_[i]) {
189        case 'Z':
190        case 'B':
191        case 'C':
192        case 'S':
193        case 'I':
194        case 'F':
195        case 'L':
196          Append(shadow_frame->GetVReg(cur_arg));
197          cur_arg++;
198          break;
199        case 'D':
200        case 'J':
201          AppendWide(shadow_frame->GetVRegLong(cur_arg));
202          cur_arg++;
203          cur_arg++;
204          break;
205#ifndef NDEBUG
206        default:
207          LOG(FATAL) << "Unexpected shorty character: " << shorty_[i];
208#endif
209      }
210    }
211  }
212
213  static void ThrowIllegalPrimitiveArgumentException(const char* expected,
214                                                     const char* found_descriptor)
215      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
216    ThrowIllegalArgumentException(nullptr,
217        StringPrintf("Invalid primitive conversion from %s to %s", expected,
218                     PrettyDescriptor(found_descriptor).c_str()).c_str());
219  }
220
221  bool BuildArgArrayFromObjectArray(const ScopedObjectAccessAlreadyRunnable& soa,
222                                    mirror::Object* receiver,
223                                    mirror::ObjectArray<mirror::Object>* args, MethodHelper& mh)
224      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
225    const DexFile::TypeList* classes = mh.GetMethod()->GetParameterTypeList();
226    // Set receiver if non-null (method is not static)
227    if (receiver != nullptr) {
228      Append(receiver);
229    }
230    for (size_t i = 1, args_offset = 0; i < shorty_len_; ++i, ++args_offset) {
231      mirror::Object* arg = args->Get(args_offset);
232      if (((shorty_[i] == 'L') && (arg != nullptr)) || ((arg == nullptr && shorty_[i] != 'L'))) {
233        mirror::Class* dst_class =
234            mh.GetClassFromTypeIdx(classes->GetTypeItem(args_offset).type_idx_);
235        if (UNLIKELY(arg == nullptr || !arg->InstanceOf(dst_class))) {
236          ThrowIllegalArgumentException(nullptr,
237              StringPrintf("method %s argument %zd has type %s, got %s",
238                  PrettyMethod(mh.GetMethod(), false).c_str(),
239                  args_offset + 1,  // Humans don't count from 0.
240                  PrettyDescriptor(dst_class).c_str(),
241                  PrettyTypeOf(arg).c_str()).c_str());
242          return false;
243        }
244      }
245
246#define DO_FIRST_ARG(match_descriptor, get_fn, append) { \
247          if (LIKELY(arg != nullptr && arg->GetClass<>()->DescriptorEquals(match_descriptor))) { \
248            mirror::ArtField* primitive_field = arg->GetClass()->GetIFields()->Get(0); \
249            append(primitive_field-> get_fn(arg));
250
251#define DO_ARG(match_descriptor, get_fn, append) \
252          } else if (LIKELY(arg != nullptr && \
253                            arg->GetClass<>()->DescriptorEquals(match_descriptor))) { \
254            mirror::ArtField* primitive_field = arg->GetClass()->GetIFields()->Get(0); \
255            append(primitive_field-> get_fn(arg));
256
257#define DO_FAIL(expected) \
258          } else { \
259            if (arg->GetClass<>()->IsPrimitive()) { \
260              std::string temp; \
261              ThrowIllegalPrimitiveArgumentException(expected, \
262                                                     arg->GetClass<>()->GetDescriptor(&temp)); \
263            } else { \
264              ThrowIllegalArgumentException(nullptr, \
265                  StringPrintf("method %s argument %zd has type %s, got %s", \
266                      PrettyMethod(mh.GetMethod(), false).c_str(), \
267                      args_offset + 1, \
268                      expected, \
269                      PrettyTypeOf(arg).c_str()).c_str()); \
270            } \
271            return false; \
272          } }
273
274      switch (shorty_[i]) {
275        case 'L':
276          Append(arg);
277          break;
278        case 'Z':
279          DO_FIRST_ARG("Ljava/lang/Boolean;", GetBoolean, Append)
280          DO_FAIL("boolean")
281          break;
282        case 'B':
283          DO_FIRST_ARG("Ljava/lang/Byte;", GetByte, Append)
284          DO_FAIL("byte")
285          break;
286        case 'C':
287          DO_FIRST_ARG("Ljava/lang/Character;", GetChar, Append)
288          DO_FAIL("char")
289          break;
290        case 'S':
291          DO_FIRST_ARG("Ljava/lang/Short;", GetShort, Append)
292          DO_ARG("Ljava/lang/Byte;", GetByte, Append)
293          DO_FAIL("short")
294          break;
295        case 'I':
296          DO_FIRST_ARG("Ljava/lang/Integer;", GetInt, Append)
297          DO_ARG("Ljava/lang/Character;", GetChar, Append)
298          DO_ARG("Ljava/lang/Short;", GetShort, Append)
299          DO_ARG("Ljava/lang/Byte;", GetByte, Append)
300          DO_FAIL("int")
301          break;
302        case 'J':
303          DO_FIRST_ARG("Ljava/lang/Long;", GetLong, AppendWide)
304          DO_ARG("Ljava/lang/Integer;", GetInt, AppendWide)
305          DO_ARG("Ljava/lang/Character;", GetChar, AppendWide)
306          DO_ARG("Ljava/lang/Short;", GetShort, AppendWide)
307          DO_ARG("Ljava/lang/Byte;", GetByte, AppendWide)
308          DO_FAIL("long")
309          break;
310        case 'F':
311          DO_FIRST_ARG("Ljava/lang/Float;", GetFloat, AppendFloat)
312          DO_ARG("Ljava/lang/Long;", GetLong, AppendFloat)
313          DO_ARG("Ljava/lang/Integer;", GetInt, AppendFloat)
314          DO_ARG("Ljava/lang/Character;", GetChar, AppendFloat)
315          DO_ARG("Ljava/lang/Short;", GetShort, AppendFloat)
316          DO_ARG("Ljava/lang/Byte;", GetByte, AppendFloat)
317          DO_FAIL("float")
318          break;
319        case 'D':
320          DO_FIRST_ARG("Ljava/lang/Double;", GetDouble, AppendDouble)
321          DO_ARG("Ljava/lang/Float;", GetFloat, AppendDouble)
322          DO_ARG("Ljava/lang/Long;", GetLong, AppendDouble)
323          DO_ARG("Ljava/lang/Integer;", GetInt, AppendDouble)
324          DO_ARG("Ljava/lang/Character;", GetChar, AppendDouble)
325          DO_ARG("Ljava/lang/Short;", GetShort, AppendDouble)
326          DO_ARG("Ljava/lang/Byte;", GetByte, AppendDouble)
327          DO_FAIL("double")
328          break;
329#ifndef NDEBUG
330        default:
331          LOG(FATAL) << "Unexpected shorty character: " << shorty_[i];
332#endif
333      }
334#undef DO_FIRST_ARG
335#undef DO_ARG
336#undef DO_FAIL
337    }
338    return true;
339  }
340
341 private:
342  enum { kSmallArgArraySize = 16 };
343  const char* const shorty_;
344  const uint32_t shorty_len_;
345  uint32_t num_bytes_;
346  uint32_t* arg_array_;
347  uint32_t small_arg_array_[kSmallArgArraySize];
348  std::unique_ptr<uint32_t[]> large_arg_array_;
349};
350
351static void CheckMethodArguments(JavaVMExt* vm, mirror::ArtMethod* m, uint32_t* args)
352    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
353  const DexFile::TypeList* params = m->GetParameterTypeList();
354  if (params == nullptr) {
355    return;  // No arguments so nothing to check.
356  }
357  uint32_t offset = 0;
358  uint32_t num_params = params->Size();
359  size_t error_count = 0;
360  if (!m->IsStatic()) {
361    offset = 1;
362  }
363  // TODO: If args contain object references, it may cause problems
364  Thread* self = Thread::Current();
365  StackHandleScope<1> hs(self);
366  Handle<mirror::ArtMethod> h_m(hs.NewHandle(m));
367  MethodHelper mh(h_m);
368  for (uint32_t i = 0; i < num_params; i++) {
369    uint16_t type_idx = params->GetTypeItem(i).type_idx_;
370    mirror::Class* param_type = mh.GetClassFromTypeIdx(type_idx);
371    if (param_type == nullptr) {
372      CHECK(self->IsExceptionPending());
373      LOG(ERROR) << "Internal error: unresolvable type for argument type in JNI invoke: "
374          << h_m->GetTypeDescriptorFromTypeIdx(type_idx) << "\n"
375          << self->GetException(nullptr)->Dump();
376      self->ClearException();
377      ++error_count;
378    } else if (!param_type->IsPrimitive()) {
379      // TODO: There is a compaction bug here since GetClassFromTypeIdx can cause thread suspension,
380      // this is a hard to fix problem since the args can contain Object*, we need to save and
381      // restore them by using a visitor similar to the ones used in the trampoline entrypoints.
382      mirror::Object* argument =
383          (reinterpret_cast<StackReference<mirror::Object>*>(&args[i + offset]))->AsMirrorPtr();
384      if (argument != nullptr && !argument->InstanceOf(param_type)) {
385        LOG(ERROR) << "JNI ERROR (app bug): attempt to pass an instance of "
386                   << PrettyTypeOf(argument) << " as argument " << (i + 1)
387                   << " to " << PrettyMethod(h_m.Get());
388        ++error_count;
389      }
390    } else if (param_type->IsPrimitiveLong() || param_type->IsPrimitiveDouble()) {
391      offset++;
392    } else {
393      int32_t arg = static_cast<int32_t>(args[i + offset]);
394      if (param_type->IsPrimitiveBoolean()) {
395        if (arg != JNI_TRUE && arg != JNI_FALSE) {
396          LOG(ERROR) << "JNI ERROR (app bug): expected jboolean (0/1) but got value of "
397              << arg << " as argument " << (i + 1) << " to " << PrettyMethod(h_m.Get());
398          ++error_count;
399        }
400      } else if (param_type->IsPrimitiveByte()) {
401        if (arg < -128 || arg > 127) {
402          LOG(ERROR) << "JNI ERROR (app bug): expected jbyte but got value of "
403              << arg << " as argument " << (i + 1) << " to " << PrettyMethod(h_m.Get());
404          ++error_count;
405        }
406      } else if (param_type->IsPrimitiveChar()) {
407        if (args[i + offset] > 0xFFFF) {
408          LOG(ERROR) << "JNI ERROR (app bug): expected jchar but got value of "
409              << arg << " as argument " << (i + 1) << " to " << PrettyMethod(h_m.Get());
410          ++error_count;
411        }
412      } else if (param_type->IsPrimitiveShort()) {
413        if (arg < -32768 || arg > 0x7FFF) {
414          LOG(ERROR) << "JNI ERROR (app bug): expected jshort but got value of "
415              << arg << " as argument " << (i + 1) << " to " << PrettyMethod(h_m.Get());
416          ++error_count;
417        }
418      }
419    }
420  }
421  if (UNLIKELY(error_count > 0)) {
422    // TODO: pass the JNI function name (such as "CallVoidMethodV") through so we can call JniAbort
423    // with an argument.
424    vm->JniAbortF(nullptr, "bad arguments passed to %s (see above for details)",
425                  PrettyMethod(h_m.Get()).c_str());
426  }
427}
428
429static mirror::ArtMethod* FindVirtualMethod(mirror::Object* receiver,
430                                            mirror::ArtMethod* method)
431    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
432  return receiver->GetClass()->FindVirtualMethodForVirtualOrInterface(method);
433}
434
435
436static void InvokeWithArgArray(const ScopedObjectAccessAlreadyRunnable& soa,
437                               mirror::ArtMethod* method, ArgArray* arg_array, JValue* result,
438                               const char* shorty)
439    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
440  uint32_t* args = arg_array->GetArray();
441  if (UNLIKELY(soa.Env()->check_jni)) {
442    CheckMethodArguments(soa.Vm(), method, args);
443  }
444  method->Invoke(soa.Self(), args, arg_array->GetNumBytes(), result, shorty);
445}
446
447JValue InvokeWithVarArgs(const ScopedObjectAccessAlreadyRunnable& soa, jobject obj, jmethodID mid,
448                         va_list args)
449    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
450  // We want to make sure that the stack is not within a small distance from the
451  // protected region in case we are calling into a leaf function whose stack
452  // check has been elided.
453  if (UNLIKELY(__builtin_frame_address(0) < soa.Self()->GetStackEnd())) {
454    ThrowStackOverflowError(soa.Self());
455    return JValue();
456  }
457
458  mirror::ArtMethod* method = soa.DecodeMethod(mid);
459  mirror::Object* receiver = method->IsStatic() ? nullptr : soa.Decode<mirror::Object*>(obj);
460  uint32_t shorty_len = 0;
461  const char* shorty = method->GetShorty(&shorty_len);
462  JValue result;
463  ArgArray arg_array(shorty, shorty_len);
464  arg_array.BuildArgArrayFromVarArgs(soa, receiver, args);
465  InvokeWithArgArray(soa, method, &arg_array, &result, shorty);
466  return result;
467}
468
469JValue InvokeWithJValues(const ScopedObjectAccessAlreadyRunnable& soa, mirror::Object* receiver,
470                         jmethodID mid, jvalue* args) {
471  // We want to make sure that the stack is not within a small distance from the
472  // protected region in case we are calling into a leaf function whose stack
473  // check has been elided.
474  if (UNLIKELY(__builtin_frame_address(0) < soa.Self()->GetStackEnd())) {
475    ThrowStackOverflowError(soa.Self());
476    return JValue();
477  }
478
479  mirror::ArtMethod* method = soa.DecodeMethod(mid);
480  uint32_t shorty_len = 0;
481  const char* shorty = method->GetShorty(&shorty_len);
482  JValue result;
483  ArgArray arg_array(shorty, shorty_len);
484  arg_array.BuildArgArrayFromJValues(soa, receiver, args);
485  InvokeWithArgArray(soa, method, &arg_array, &result, shorty);
486  return result;
487}
488
489JValue InvokeVirtualOrInterfaceWithJValues(const ScopedObjectAccessAlreadyRunnable& soa,
490                                           mirror::Object* receiver, jmethodID mid, jvalue* args) {
491  // We want to make sure that the stack is not within a small distance from the
492  // protected region in case we are calling into a leaf function whose stack
493  // check has been elided.
494  if (UNLIKELY(__builtin_frame_address(0) < soa.Self()->GetStackEnd())) {
495    ThrowStackOverflowError(soa.Self());
496    return JValue();
497  }
498
499  mirror::ArtMethod* method = FindVirtualMethod(receiver, soa.DecodeMethod(mid));
500  uint32_t shorty_len = 0;
501  const char* shorty = method->GetShorty(&shorty_len);
502  JValue result;
503  ArgArray arg_array(shorty, shorty_len);
504  arg_array.BuildArgArrayFromJValues(soa, receiver, args);
505  InvokeWithArgArray(soa, method, &arg_array, &result, shorty);
506  return result;
507}
508
509JValue InvokeVirtualOrInterfaceWithVarArgs(const ScopedObjectAccessAlreadyRunnable& soa,
510                                           jobject obj, jmethodID mid, va_list args) {
511  // We want to make sure that the stack is not within a small distance from the
512  // protected region in case we are calling into a leaf function whose stack
513  // check has been elided.
514  if (UNLIKELY(__builtin_frame_address(0) < soa.Self()->GetStackEnd())) {
515    ThrowStackOverflowError(soa.Self());
516    return JValue();
517  }
518
519  mirror::Object* receiver = soa.Decode<mirror::Object*>(obj);
520  mirror::ArtMethod* method = FindVirtualMethod(receiver, soa.DecodeMethod(mid));
521  uint32_t shorty_len = 0;
522  const char* shorty = method->GetShorty(&shorty_len);
523  JValue result;
524  ArgArray arg_array(shorty, shorty_len);
525  arg_array.BuildArgArrayFromVarArgs(soa, receiver, args);
526  InvokeWithArgArray(soa, method, &arg_array, &result, shorty);
527  return result;
528}
529
530void InvokeWithShadowFrame(Thread* self, ShadowFrame* shadow_frame, uint16_t arg_offset,
531                           MethodHelper& mh, JValue* result) {
532  // We want to make sure that the stack is not within a small distance from the
533  // protected region in case we are calling into a leaf function whose stack
534  // check has been elided.
535  if (UNLIKELY(__builtin_frame_address(0) < self->GetStackEnd())) {
536    ThrowStackOverflowError(self);
537    return;
538  }
539
540  ArgArray arg_array(mh.GetShorty(), mh.GetShortyLength());
541  arg_array.BuildArgArrayFromFrame(shadow_frame, arg_offset);
542  shadow_frame->GetMethod()->Invoke(self, arg_array.GetArray(), arg_array.GetNumBytes(), result,
543                                    mh.GetShorty());
544}
545
546jobject InvokeMethod(const ScopedObjectAccessAlreadyRunnable& soa, jobject javaMethod,
547                     jobject javaReceiver, jobject javaArgs, bool accessible) {
548  // We want to make sure that the stack is not within a small distance from the
549  // protected region in case we are calling into a leaf function whose stack
550  // check has been elided.
551  if (UNLIKELY(__builtin_frame_address(0) <
552               soa.Self()->GetStackEndForInterpreter(true))) {
553    ThrowStackOverflowError(soa.Self());
554    return nullptr;
555  }
556
557  mirror::ArtMethod* m = mirror::ArtMethod::FromReflectedMethod(soa, javaMethod);
558
559  mirror::Class* declaring_class = m->GetDeclaringClass();
560  if (UNLIKELY(!declaring_class->IsInitialized())) {
561    StackHandleScope<1> hs(soa.Self());
562    Handle<mirror::Class> h_class(hs.NewHandle(declaring_class));
563    if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(soa.Self(), h_class, true, true)) {
564      return nullptr;
565    }
566    declaring_class = h_class.Get();
567  }
568
569  mirror::Object* receiver = nullptr;
570  if (!m->IsStatic()) {
571    // Check that the receiver is non-null and an instance of the field's declaring class.
572    receiver = soa.Decode<mirror::Object*>(javaReceiver);
573    if (!VerifyObjectIsClass(receiver, declaring_class)) {
574      return NULL;
575    }
576
577    // Find the actual implementation of the virtual method.
578    m = receiver->GetClass()->FindVirtualMethodForVirtualOrInterface(m);
579  }
580
581  // Get our arrays of arguments and their types, and check they're the same size.
582  mirror::ObjectArray<mirror::Object>* objects =
583      soa.Decode<mirror::ObjectArray<mirror::Object>*>(javaArgs);
584  const DexFile::TypeList* classes = m->GetParameterTypeList();
585  uint32_t classes_size = (classes == nullptr) ? 0 : classes->Size();
586  uint32_t arg_count = (objects != nullptr) ? objects->GetLength() : 0;
587  if (arg_count != classes_size) {
588    ThrowIllegalArgumentException(NULL,
589                                  StringPrintf("Wrong number of arguments; expected %d, got %d",
590                                               classes_size, arg_count).c_str());
591    return NULL;
592  }
593
594  // If method is not set to be accessible, verify it can be accessed by the caller.
595  if (!accessible && !VerifyAccess(soa.Self(), receiver, declaring_class, m->GetAccessFlags())) {
596    ThrowIllegalAccessException(nullptr, StringPrintf("Cannot access method: %s",
597                                                      PrettyMethod(m).c_str()).c_str());
598    return nullptr;
599  }
600
601  // Invoke the method.
602  JValue result;
603  uint32_t shorty_len = 0;
604  const char* shorty = m->GetShorty(&shorty_len);
605  ArgArray arg_array(shorty, shorty_len);
606  StackHandleScope<1> hs(soa.Self());
607  MethodHelper mh(hs.NewHandle(m));
608  if (!arg_array.BuildArgArrayFromObjectArray(soa, receiver, objects, mh)) {
609    CHECK(soa.Self()->IsExceptionPending());
610    return nullptr;
611  }
612
613  InvokeWithArgArray(soa, m, &arg_array, &result, shorty);
614
615  // Wrap any exception with "Ljava/lang/reflect/InvocationTargetException;" and return early.
616  if (soa.Self()->IsExceptionPending()) {
617    jthrowable th = soa.Env()->ExceptionOccurred();
618    soa.Env()->ExceptionClear();
619    jclass exception_class = soa.Env()->FindClass("java/lang/reflect/InvocationTargetException");
620    jmethodID mid = soa.Env()->GetMethodID(exception_class, "<init>", "(Ljava/lang/Throwable;)V");
621    jobject exception_instance = soa.Env()->NewObject(exception_class, mid, th);
622    soa.Env()->Throw(reinterpret_cast<jthrowable>(exception_instance));
623    return NULL;
624  }
625
626  // Box if necessary and return.
627  return soa.AddLocalReference<jobject>(BoxPrimitive(mh.GetReturnType()->GetPrimitiveType(),
628                                                     result));
629}
630
631bool VerifyObjectIsClass(mirror::Object* o, mirror::Class* c) {
632  if (o == NULL) {
633    ThrowNullPointerException(NULL, "null receiver");
634    return false;
635  } else if (!o->InstanceOf(c)) {
636    std::string expected_class_name(PrettyDescriptor(c));
637    std::string actual_class_name(PrettyTypeOf(o));
638    ThrowIllegalArgumentException(NULL,
639                                  StringPrintf("Expected receiver of type %s, but got %s",
640                                               expected_class_name.c_str(),
641                                               actual_class_name.c_str()).c_str());
642    return false;
643  }
644  return true;
645}
646
647mirror::Object* BoxPrimitive(Primitive::Type src_class, const JValue& value) {
648  if (src_class == Primitive::kPrimNot) {
649    return value.GetL();
650  }
651  if (src_class == Primitive::kPrimVoid) {
652    // There's no such thing as a void field, and void methods invoked via reflection return null.
653    return nullptr;
654  }
655
656  jmethodID m = nullptr;
657  const char* shorty;
658  switch (src_class) {
659  case Primitive::kPrimBoolean:
660    m = WellKnownClasses::java_lang_Boolean_valueOf;
661    shorty = "LZ";
662    break;
663  case Primitive::kPrimByte:
664    m = WellKnownClasses::java_lang_Byte_valueOf;
665    shorty = "LB";
666    break;
667  case Primitive::kPrimChar:
668    m = WellKnownClasses::java_lang_Character_valueOf;
669    shorty = "LC";
670    break;
671  case Primitive::kPrimDouble:
672    m = WellKnownClasses::java_lang_Double_valueOf;
673    shorty = "LD";
674    break;
675  case Primitive::kPrimFloat:
676    m = WellKnownClasses::java_lang_Float_valueOf;
677    shorty = "LF";
678    break;
679  case Primitive::kPrimInt:
680    m = WellKnownClasses::java_lang_Integer_valueOf;
681    shorty = "LI";
682    break;
683  case Primitive::kPrimLong:
684    m = WellKnownClasses::java_lang_Long_valueOf;
685    shorty = "LJ";
686    break;
687  case Primitive::kPrimShort:
688    m = WellKnownClasses::java_lang_Short_valueOf;
689    shorty = "LS";
690    break;
691  default:
692    LOG(FATAL) << static_cast<int>(src_class);
693    shorty = nullptr;
694  }
695
696  ScopedObjectAccessUnchecked soa(Thread::Current());
697  DCHECK_EQ(soa.Self()->GetState(), kRunnable);
698
699  ArgArray arg_array(shorty, 2);
700  JValue result;
701  if (src_class == Primitive::kPrimDouble || src_class == Primitive::kPrimLong) {
702    arg_array.AppendWide(value.GetJ());
703  } else {
704    arg_array.Append(value.GetI());
705  }
706
707  soa.DecodeMethod(m)->Invoke(soa.Self(), arg_array.GetArray(), arg_array.GetNumBytes(),
708                              &result, shorty);
709  return result.GetL();
710}
711
712static std::string UnboxingFailureKind(mirror::ArtField* f)
713    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
714  if (f != nullptr) {
715    return "field " + PrettyField(f, false);
716  }
717  return "result";
718}
719
720static bool UnboxPrimitive(const ThrowLocation* throw_location, mirror::Object* o,
721                           mirror::Class* dst_class, mirror::ArtField* f,
722                           JValue* unboxed_value)
723    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
724  bool unbox_for_result = (f == nullptr);
725  if (!dst_class->IsPrimitive()) {
726    if (UNLIKELY(o != nullptr && !o->InstanceOf(dst_class))) {
727      if (!unbox_for_result) {
728        ThrowIllegalArgumentException(throw_location,
729                                      StringPrintf("%s has type %s, got %s",
730                                                   UnboxingFailureKind(f).c_str(),
731                                                   PrettyDescriptor(dst_class).c_str(),
732                                                   PrettyTypeOf(o).c_str()).c_str());
733      } else {
734        ThrowClassCastException(throw_location,
735                                StringPrintf("Couldn't convert result of type %s to %s",
736                                             PrettyTypeOf(o).c_str(),
737                                             PrettyDescriptor(dst_class).c_str()).c_str());
738      }
739      return false;
740    }
741    unboxed_value->SetL(o);
742    return true;
743  }
744  if (UNLIKELY(dst_class->GetPrimitiveType() == Primitive::kPrimVoid)) {
745    ThrowIllegalArgumentException(throw_location,
746                                  StringPrintf("Can't unbox %s to void",
747                                               UnboxingFailureKind(f).c_str()).c_str());
748    return false;
749  }
750  if (UNLIKELY(o == nullptr)) {
751    if (!unbox_for_result) {
752      ThrowIllegalArgumentException(throw_location,
753                                    StringPrintf("%s has type %s, got null",
754                                                 UnboxingFailureKind(f).c_str(),
755                                                 PrettyDescriptor(dst_class).c_str()).c_str());
756    } else {
757      ThrowNullPointerException(throw_location,
758                                StringPrintf("Expected to unbox a '%s' primitive type but was returned null",
759                                             PrettyDescriptor(dst_class).c_str()).c_str());
760    }
761    return false;
762  }
763
764  JValue boxed_value;
765  mirror::Class* klass = o->GetClass();
766  mirror::Class* src_class = nullptr;
767  ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
768  mirror::ArtField* primitive_field = o->GetClass()->GetIFields()->Get(0);
769  if (klass->DescriptorEquals("Ljava/lang/Boolean;")) {
770    src_class = class_linker->FindPrimitiveClass('Z');
771    boxed_value.SetZ(primitive_field->GetBoolean(o));
772  } else if (klass->DescriptorEquals("Ljava/lang/Byte;")) {
773    src_class = class_linker->FindPrimitiveClass('B');
774    boxed_value.SetB(primitive_field->GetByte(o));
775  } else if (klass->DescriptorEquals("Ljava/lang/Character;")) {
776    src_class = class_linker->FindPrimitiveClass('C');
777    boxed_value.SetC(primitive_field->GetChar(o));
778  } else if (klass->DescriptorEquals("Ljava/lang/Float;")) {
779    src_class = class_linker->FindPrimitiveClass('F');
780    boxed_value.SetF(primitive_field->GetFloat(o));
781  } else if (klass->DescriptorEquals("Ljava/lang/Double;")) {
782    src_class = class_linker->FindPrimitiveClass('D');
783    boxed_value.SetD(primitive_field->GetDouble(o));
784  } else if (klass->DescriptorEquals("Ljava/lang/Integer;")) {
785    src_class = class_linker->FindPrimitiveClass('I');
786    boxed_value.SetI(primitive_field->GetInt(o));
787  } else if (klass->DescriptorEquals("Ljava/lang/Long;")) {
788    src_class = class_linker->FindPrimitiveClass('J');
789    boxed_value.SetJ(primitive_field->GetLong(o));
790  } else if (klass->DescriptorEquals("Ljava/lang/Short;")) {
791    src_class = class_linker->FindPrimitiveClass('S');
792    boxed_value.SetS(primitive_field->GetShort(o));
793  } else {
794    std::string temp;
795    ThrowIllegalArgumentException(throw_location,
796        StringPrintf("%s has type %s, got %s", UnboxingFailureKind(f).c_str(),
797            PrettyDescriptor(dst_class).c_str(),
798            PrettyDescriptor(o->GetClass()->GetDescriptor(&temp)).c_str()).c_str());
799    return false;
800  }
801
802  return ConvertPrimitiveValue(throw_location, unbox_for_result,
803                               src_class->GetPrimitiveType(), dst_class->GetPrimitiveType(),
804                               boxed_value, unboxed_value);
805}
806
807bool UnboxPrimitiveForField(mirror::Object* o, mirror::Class* dst_class, mirror::ArtField* f,
808                            JValue* unboxed_value) {
809  DCHECK(f != nullptr);
810  return UnboxPrimitive(nullptr, o, dst_class, f, unboxed_value);
811}
812
813bool UnboxPrimitiveForResult(const ThrowLocation& throw_location, mirror::Object* o,
814                             mirror::Class* dst_class, JValue* unboxed_value) {
815  return UnboxPrimitive(&throw_location, o, dst_class, nullptr, unboxed_value);
816}
817
818bool VerifyAccess(Thread* self, mirror::Object* obj, mirror::Class* declaring_class, uint32_t access_flags) {
819  if ((access_flags & kAccPublic) != 0) {
820    return true;
821  }
822  NthCallerVisitor visitor(self, 2);
823  visitor.WalkStack();
824  if (UNLIKELY(visitor.caller == nullptr)) {
825    // The caller is an attached native thread.
826    return false;
827  }
828  mirror::Class* caller_class = visitor.caller->GetDeclaringClass();
829  if (caller_class == declaring_class) {
830    return true;
831  }
832  if ((access_flags & kAccPrivate) != 0) {
833    return false;
834  }
835  if ((access_flags & kAccProtected) != 0) {
836    if (obj != nullptr && !obj->InstanceOf(caller_class) &&
837        !declaring_class->IsInSamePackage(caller_class)) {
838      return false;
839    } else if (declaring_class->IsAssignableFrom(caller_class)) {
840      return true;
841    }
842  }
843  return declaring_class->IsInSamePackage(caller_class);
844}
845
846}  // namespace art
847