1 /*
2  * Copyright (C) 2016 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_reflect_Executable.h"
18 
19 #include "android-base/stringprintf.h"
20 #include "nativehelper/jni_macros.h"
21 
22 #include "art_method-inl.h"
23 #include "class_root.h"
24 #include "dex/dex_file_annotations.h"
25 #include "handle.h"
26 #include "jni/jni_internal.h"
27 #include "mirror/class-alloc-inl.h"
28 #include "mirror/class-inl.h"
29 #include "mirror/method.h"
30 #include "mirror/object-inl.h"
31 #include "mirror/object_array-alloc-inl.h"
32 #include "mirror/object_array-inl.h"
33 #include "native_util.h"
34 #include "reflection.h"
35 #include "scoped_fast_native_object_access-inl.h"
36 #include "well_known_classes.h"
37 
38 namespace art {
39 
40 using android::base::StringPrintf;
41 
Executable_getDeclaredAnnotationsNative(JNIEnv * env,jobject javaMethod)42 static jobjectArray Executable_getDeclaredAnnotationsNative(JNIEnv* env, jobject javaMethod) {
43   ScopedFastNativeObjectAccess soa(env);
44   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
45   if (method->GetDeclaringClass()->IsProxyClass()) {
46     // Return an empty array instead of a null pointer.
47     ObjPtr<mirror::Class> annotation_array_class =
48         soa.Decode<mirror::Class>(WellKnownClasses::java_lang_annotation_Annotation__array);
49     ObjPtr<mirror::ObjectArray<mirror::Object>> empty_array =
50         mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), annotation_array_class, 0);
51     return soa.AddLocalReference<jobjectArray>(empty_array);
52   }
53   return soa.AddLocalReference<jobjectArray>(annotations::GetAnnotationsForMethod(method));
54 }
55 
Executable_getAnnotationNative(JNIEnv * env,jobject javaMethod,jclass annotationType)56 static jobject Executable_getAnnotationNative(JNIEnv* env,
57                                               jobject javaMethod,
58                                               jclass annotationType) {
59   ScopedFastNativeObjectAccess soa(env);
60   StackHandleScope<1> hs(soa.Self());
61   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
62   if (method->IsProxyMethod()) {
63     return nullptr;
64   } else {
65     Handle<mirror::Class> klass(hs.NewHandle(soa.Decode<mirror::Class>(annotationType)));
66     return soa.AddLocalReference<jobject>(annotations::GetAnnotationForMethod(method, klass));
67   }
68 }
69 
Executable_getSignatureAnnotation(JNIEnv * env,jobject javaMethod)70 static jobjectArray Executable_getSignatureAnnotation(JNIEnv* env, jobject javaMethod) {
71   ScopedFastNativeObjectAccess soa(env);
72   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
73   if (method->GetDeclaringClass()->IsProxyClass()) {
74     return nullptr;
75   }
76   return soa.AddLocalReference<jobjectArray>(annotations::GetSignatureAnnotationForMethod(method));
77 }
78 
79 
Executable_getParameterAnnotationsNative(JNIEnv * env,jobject javaMethod)80 static jobjectArray Executable_getParameterAnnotationsNative(JNIEnv* env, jobject javaMethod) {
81   ScopedFastNativeObjectAccess soa(env);
82   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
83   if (method->IsProxyMethod()) {
84     return nullptr;
85   }
86 
87   StackHandleScope<4> hs(soa.Self());
88   Handle<mirror::ObjectArray<mirror::Object>> annotations =
89       hs.NewHandle(annotations::GetParameterAnnotations(method));
90   if (annotations.IsNull()) {
91     return nullptr;
92   }
93 
94   // If the method is not a constructor, or has parameter annotations
95   // for each parameter, then we can return those annotations
96   // unmodified. Otherwise, we need to look at whether the
97   // constructor has implicit parameters as these may need padding
98   // with empty parameter annotations.
99   if (!method->IsConstructor() ||
100       annotations->GetLength() == static_cast<int>(method->GetNumberOfParameters())) {
101     return soa.AddLocalReference<jobjectArray>(annotations.Get());
102   }
103 
104   // If declaring class is a local or an enum, do not pad parameter
105   // annotations, as the implicit constructor parameters are an implementation
106   // detail rather than required by JLS.
107   Handle<mirror::Class> declaring_class = hs.NewHandle(method->GetDeclaringClass());
108   if (annotations::GetEnclosingMethod(declaring_class) != nullptr ||
109       declaring_class->IsEnum()) {
110     return soa.AddLocalReference<jobjectArray>(annotations.Get());
111   }
112 
113   // Prepare to resize the annotations so there is 1:1 correspondence
114   // with the constructor parameters.
115   Handle<mirror::ObjectArray<mirror::Object>> resized_annotations = hs.NewHandle(
116       mirror::ObjectArray<mirror::Object>::Alloc(
117           soa.Self(),
118           annotations->GetClass(),
119           static_cast<int>(method->GetNumberOfParameters())));
120   if (resized_annotations.IsNull()) {
121     DCHECK(soa.Self()->IsExceptionPending());
122     return nullptr;
123   }
124 
125   static constexpr bool kTransactionActive = false;
126   const int32_t offset = resized_annotations->GetLength() - annotations->GetLength();
127   if (offset > 0) {
128     // Workaround for dexers (d8/dx) that do not insert annotations
129     // for implicit parameters (b/68033708).
130     ObjPtr<mirror::Class> annotation_array_class =
131         soa.Decode<mirror::Class>(WellKnownClasses::java_lang_annotation_Annotation__array);
132     Handle<mirror::ObjectArray<mirror::Object>> empty_annotations = hs.NewHandle(
133         mirror::ObjectArray<mirror::Object>::Alloc(soa.Self(), annotation_array_class, 0));
134     if (empty_annotations.IsNull()) {
135       DCHECK(soa.Self()->IsExceptionPending());
136       return nullptr;
137     }
138     for (int i = 0; i < offset; ++i) {
139       resized_annotations->SetWithoutChecks<kTransactionActive>(i, empty_annotations.Get());
140     }
141     for (int i = 0; i < annotations->GetLength(); ++i) {
142       ObjPtr<mirror::Object> annotation = annotations->GetWithoutChecks(i);
143       resized_annotations->SetWithoutChecks<kTransactionActive>(i + offset, annotation);
144     }
145   } else {
146     // Workaround for Jack (defunct) erroneously inserting annotations
147     // for local classes (b/68033708).
148     DCHECK_LT(offset, 0);
149     for (int i = 0; i < resized_annotations->GetLength(); ++i) {
150       ObjPtr<mirror::Object> annotation = annotations->GetWithoutChecks(i - offset);
151       resized_annotations->SetWithoutChecks<kTransactionActive>(i, annotation);
152     }
153   }
154   return soa.AddLocalReference<jobjectArray>(resized_annotations.Get());
155 }
156 
Executable_getParameters0(JNIEnv * env,jobject javaMethod)157 static jobjectArray Executable_getParameters0(JNIEnv* env, jobject javaMethod) {
158   ScopedFastNativeObjectAccess soa(env);
159   Thread* self = soa.Self();
160   StackHandleScope<8> hs(self);
161 
162   Handle<mirror::Method> executable = hs.NewHandle(soa.Decode<mirror::Method>(javaMethod));
163   ArtMethod* art_method = executable.Get()->GetArtMethod();
164   if (art_method->GetDeclaringClass()->IsProxyClass()) {
165     return nullptr;
166   }
167 
168   // Find the MethodParameters system annotation.
169   MutableHandle<mirror::ObjectArray<mirror::String>> names =
170       hs.NewHandle<mirror::ObjectArray<mirror::String>>(nullptr);
171   MutableHandle<mirror::IntArray> access_flags = hs.NewHandle<mirror::IntArray>(nullptr);
172   if (!annotations::GetParametersMetadataForMethod(art_method, &names, &access_flags)) {
173     return nullptr;
174   }
175 
176   // Validate the MethodParameters system annotation data.
177   if (UNLIKELY(names == nullptr || access_flags == nullptr)) {
178     ThrowIllegalArgumentException(
179         StringPrintf("Missing parameter metadata for names or access flags for %s",
180                      art_method->PrettyMethod().c_str()).c_str());
181     return nullptr;
182   }
183 
184   // Check array sizes match each other
185   int32_t names_count = names.Get()->GetLength();
186   int32_t access_flags_count = access_flags.Get()->GetLength();
187   if (names_count != access_flags_count) {
188     ThrowIllegalArgumentException(
189         StringPrintf(
190             "Inconsistent parameter metadata for %s. names length: %d, access flags length: %d",
191             art_method->PrettyMethod().c_str(),
192             names_count,
193             access_flags_count).c_str());
194     return nullptr;
195   }
196 
197   // Instantiate a Parameter[] to hold the result.
198   Handle<mirror::Class> parameter_array_class =
199       hs.NewHandle(
200           soa.Decode<mirror::Class>(WellKnownClasses::java_lang_reflect_Parameter__array));
201   Handle<mirror::ObjectArray<mirror::Object>> parameter_array =
202       hs.NewHandle(
203           mirror::ObjectArray<mirror::Object>::Alloc(self,
204                                                      parameter_array_class.Get(),
205                                                      names_count));
206   if (UNLIKELY(parameter_array == nullptr)) {
207     self->AssertPendingException();
208     return nullptr;
209   }
210 
211   Handle<mirror::Class> parameter_class =
212       hs.NewHandle(soa.Decode<mirror::Class>(WellKnownClasses::java_lang_reflect_Parameter));
213   ArtMethod* parameter_init =
214       jni::DecodeArtMethod(WellKnownClasses::java_lang_reflect_Parameter_init);
215 
216   // Mutable handles used in the loop below to ensure cleanup without scaling the number of
217   // handles by the number of parameters.
218   MutableHandle<mirror::String> name = hs.NewHandle<mirror::String>(nullptr);
219   MutableHandle<mirror::Object> parameter = hs.NewHandle<mirror::Object>(nullptr);
220 
221   // Populate the Parameter[] to return.
222   for (int32_t parameter_index = 0; parameter_index < names_count; parameter_index++) {
223     name.Assign(names.Get()->Get(parameter_index));
224     int32_t modifiers = access_flags.Get()->Get(parameter_index);
225 
226     // Allocate / initialize the Parameter to add to parameter_array.
227     parameter.Assign(parameter_class->AllocObject(self));
228     if (UNLIKELY(parameter == nullptr)) {
229       self->AssertPendingOOMException();
230       return nullptr;
231     }
232 
233     uint32_t args[5] = { PointerToLowMemUInt32(parameter.Get()),
234                          PointerToLowMemUInt32(name.Get()),
235                          static_cast<uint32_t>(modifiers),
236                          PointerToLowMemUInt32(executable.Get()),
237                          static_cast<uint32_t>(parameter_index)
238     };
239     JValue result;
240     static const char* method_signature = "VLILI";  // return + parameter types
241     parameter_init->Invoke(self, args, sizeof(args), &result, method_signature);
242     if (UNLIKELY(self->IsExceptionPending())) {
243       return nullptr;
244     }
245 
246     // Store the Parameter in the Parameter[].
247     parameter_array.Get()->Set(parameter_index, parameter.Get());
248     if (UNLIKELY(self->IsExceptionPending())) {
249       return nullptr;
250     }
251   }
252   return soa.AddLocalReference<jobjectArray>(parameter_array.Get());
253 }
254 
Executable_isAnnotationPresentNative(JNIEnv * env,jobject javaMethod,jclass annotationType)255 static jboolean Executable_isAnnotationPresentNative(JNIEnv* env,
256                                                      jobject javaMethod,
257                                                      jclass annotationType) {
258   ScopedFastNativeObjectAccess soa(env);
259   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
260   if (method->GetDeclaringClass()->IsProxyClass()) {
261     return false;
262   }
263   StackHandleScope<1> hs(soa.Self());
264   Handle<mirror::Class> klass(hs.NewHandle(soa.Decode<mirror::Class>(annotationType)));
265   return annotations::IsMethodAnnotationPresent(method, klass);
266 }
267 
Executable_compareMethodParametersInternal(JNIEnv * env,jobject thisMethod,jobject otherMethod)268 static jint Executable_compareMethodParametersInternal(JNIEnv* env,
269                                                        jobject thisMethod,
270                                                        jobject otherMethod) {
271   ScopedFastNativeObjectAccess soa(env);
272   ArtMethod* this_method = ArtMethod::FromReflectedMethod(soa, thisMethod);
273   ArtMethod* other_method = ArtMethod::FromReflectedMethod(soa, otherMethod);
274 
275   this_method = this_method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
276   other_method = other_method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
277 
278   const dex::TypeList* this_list = this_method->GetParameterTypeList();
279   const dex::TypeList* other_list = other_method->GetParameterTypeList();
280 
281   if (this_list == other_list) {
282     return 0;
283   }
284 
285   if (this_list == nullptr && other_list != nullptr) {
286     return -1;
287   }
288 
289   if (other_list == nullptr && this_list != nullptr) {
290     return 1;
291   }
292 
293   const int32_t this_size = this_list->Size();
294   const int32_t other_size = other_list->Size();
295 
296   if (this_size != other_size) {
297     return (this_size - other_size);
298   }
299 
300   for (int32_t i = 0; i < this_size; ++i) {
301     const dex::TypeId& lhs = this_method->GetDexFile()->GetTypeId(
302         this_list->GetTypeItem(i).type_idx_);
303     const dex::TypeId& rhs = other_method->GetDexFile()->GetTypeId(
304         other_list->GetTypeItem(i).type_idx_);
305 
306     uint32_t lhs_len, rhs_len;
307     const char* lhs_data = this_method->GetDexFile()->StringDataAndUtf16LengthByIdx(
308         lhs.descriptor_idx_, &lhs_len);
309     const char* rhs_data = other_method->GetDexFile()->StringDataAndUtf16LengthByIdx(
310         rhs.descriptor_idx_, &rhs_len);
311 
312     int cmp = strcmp(lhs_data, rhs_data);
313     if (cmp != 0) {
314       return (cmp < 0) ? -1 : 1;
315     }
316   }
317 
318   return 0;
319 }
320 
Executable_getMethodNameInternal(JNIEnv * env,jobject javaMethod)321 static jstring Executable_getMethodNameInternal(JNIEnv* env, jobject javaMethod) {
322   ScopedFastNativeObjectAccess soa(env);
323   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
324   method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
325   return soa.AddLocalReference<jstring>(method->ResolveNameString());
326 }
327 
Executable_getMethodReturnTypeInternal(JNIEnv * env,jobject javaMethod)328 static jclass Executable_getMethodReturnTypeInternal(JNIEnv* env, jobject javaMethod) {
329   ScopedFastNativeObjectAccess soa(env);
330   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
331   method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
332   ObjPtr<mirror::Class> return_type(method->ResolveReturnType());
333   if (return_type.IsNull()) {
334     CHECK(soa.Self()->IsExceptionPending());
335     return nullptr;
336   }
337 
338   return soa.AddLocalReference<jclass>(return_type);
339 }
340 
Executable_getParameterTypesInternal(JNIEnv * env,jobject javaMethod)341 static jobjectArray Executable_getParameterTypesInternal(JNIEnv* env, jobject javaMethod) {
342   ScopedFastNativeObjectAccess soa(env);
343   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
344   method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
345 
346   const dex::TypeList* params = method->GetParameterTypeList();
347   if (params == nullptr) {
348     return nullptr;
349   }
350 
351   const uint32_t num_params = params->Size();
352 
353   StackHandleScope<2> hs(soa.Self());
354   ObjPtr<mirror::Class> class_array_class = GetClassRoot<mirror::ObjectArray<mirror::Class>>();
355   Handle<mirror::ObjectArray<mirror::Class>> ptypes = hs.NewHandle(
356       mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, num_params));
357   if (ptypes.IsNull()) {
358     DCHECK(soa.Self()->IsExceptionPending());
359     return nullptr;
360   }
361 
362   MutableHandle<mirror::Class> param(hs.NewHandle<mirror::Class>(nullptr));
363   for (uint32_t i = 0; i < num_params; ++i) {
364     const dex::TypeIndex type_idx = params->GetTypeItem(i).type_idx_;
365     param.Assign(Runtime::Current()->GetClassLinker()->ResolveType(type_idx, method));
366     if (param.Get() == nullptr) {
367       DCHECK(soa.Self()->IsExceptionPending());
368       return nullptr;
369     }
370     ptypes->SetWithoutChecks<false>(i, param.Get());
371   }
372 
373   return soa.AddLocalReference<jobjectArray>(ptypes.Get());
374 }
375 
Executable_getParameterCountInternal(JNIEnv * env,jobject javaMethod)376 static jint Executable_getParameterCountInternal(JNIEnv* env, jobject javaMethod) {
377   ScopedFastNativeObjectAccess soa(env);
378   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
379   method = method->GetInterfaceMethodIfProxy(kRuntimePointerSize);
380 
381   const dex::TypeList* params = method->GetParameterTypeList();
382   return (params == nullptr) ? 0 : params->Size();
383 }
384 
385 
386 static JNINativeMethod gMethods[] = {
387   FAST_NATIVE_METHOD(Executable, compareMethodParametersInternal,
388                      "(Ljava/lang/reflect/Method;)I"),
389   FAST_NATIVE_METHOD(Executable, getAnnotationNative,
390                      "(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;"),
391   FAST_NATIVE_METHOD(Executable, getDeclaredAnnotationsNative,
392                      "()[Ljava/lang/annotation/Annotation;"),
393   FAST_NATIVE_METHOD(Executable, getParameterAnnotationsNative,
394                      "()[[Ljava/lang/annotation/Annotation;"),
395   FAST_NATIVE_METHOD(Executable, getMethodNameInternal, "()Ljava/lang/String;"),
396   FAST_NATIVE_METHOD(Executable, getMethodReturnTypeInternal, "()Ljava/lang/Class;"),
397   FAST_NATIVE_METHOD(Executable, getParameterTypesInternal, "()[Ljava/lang/Class;"),
398   FAST_NATIVE_METHOD(Executable, getParameterCountInternal, "()I"),
399   FAST_NATIVE_METHOD(Executable, getParameters0, "()[Ljava/lang/reflect/Parameter;"),
400   FAST_NATIVE_METHOD(Executable, getSignatureAnnotation, "()[Ljava/lang/String;"),
401   FAST_NATIVE_METHOD(Executable, isAnnotationPresentNative, "(Ljava/lang/Class;)Z"),
402 };
403 
register_java_lang_reflect_Executable(JNIEnv * env)404 void register_java_lang_reflect_Executable(JNIEnv* env) {
405   REGISTER_NATIVE_METHODS("java/lang/reflect/Executable");
406 }
407 
408 }  // namespace art
409