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      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 "jni_compiler.h"
     18 
     19 #include <algorithm>
     20 #include <memory>
     21 #include <vector>
     22 #include <fstream>
     23 
     24 #include "art_method.h"
     25 #include "base/arena_allocator.h"
     26 #include "base/logging.h"
     27 #include "base/macros.h"
     28 #include "calling_convention.h"
     29 #include "class_linker.h"
     30 #include "compiled_method.h"
     31 #include "dex_file-inl.h"
     32 #include "driver/compiler_driver.h"
     33 #include "driver/compiler_options.h"
     34 #include "entrypoints/quick/quick_entrypoints.h"
     35 #include "jni_env_ext.h"
     36 #include "utils/assembler.h"
     37 #include "utils/managed_register.h"
     38 #include "utils/arm/managed_register_arm.h"
     39 #include "utils/arm64/managed_register_arm64.h"
     40 #include "utils/mips/managed_register_mips.h"
     41 #include "utils/mips64/managed_register_mips64.h"
     42 #include "utils/x86/managed_register_x86.h"
     43 #include "thread.h"
     44 
     45 #define __ jni_asm->
     46 
     47 namespace art {
     48 
     49 static void CopyParameter(Assembler* jni_asm,
     50                           ManagedRuntimeCallingConvention* mr_conv,
     51                           JniCallingConvention* jni_conv,
     52                           size_t frame_size, size_t out_arg_size);
     53 static void SetNativeParameter(Assembler* jni_asm,
     54                                JniCallingConvention* jni_conv,
     55                                ManagedRegister in_reg);
     56 
     57 // Generate the JNI bridge for the given method, general contract:
     58 // - Arguments are in the managed runtime format, either on stack or in
     59 //   registers, a reference to the method object is supplied as part of this
     60 //   convention.
     61 //
     62 CompiledMethod* ArtJniCompileMethodInternal(CompilerDriver* driver,
     63                                             uint32_t access_flags, uint32_t method_idx,
     64                                             const DexFile& dex_file) {
     65   const bool is_native = (access_flags & kAccNative) != 0;
     66   CHECK(is_native);
     67   const bool is_static = (access_flags & kAccStatic) != 0;
     68   const bool is_synchronized = (access_flags & kAccSynchronized) != 0;
     69   const char* shorty = dex_file.GetMethodShorty(dex_file.GetMethodId(method_idx));
     70   InstructionSet instruction_set = driver->GetInstructionSet();
     71   const InstructionSetFeatures* instruction_set_features = driver->GetInstructionSetFeatures();
     72   const bool is_64_bit_target = Is64BitInstructionSet(instruction_set);
     73 
     74   ArenaPool pool;
     75   ArenaAllocator arena(&pool);
     76 
     77   // Calling conventions used to iterate over parameters to method
     78   std::unique_ptr<JniCallingConvention> main_jni_conv(
     79       JniCallingConvention::Create(&arena, is_static, is_synchronized, shorty, instruction_set));
     80   bool reference_return = main_jni_conv->IsReturnAReference();
     81 
     82   std::unique_ptr<ManagedRuntimeCallingConvention> mr_conv(
     83       ManagedRuntimeCallingConvention::Create(
     84           &arena, is_static, is_synchronized, shorty, instruction_set));
     85 
     86   // Calling conventions to call into JNI method "end" possibly passing a returned reference, the
     87   //     method and the current thread.
     88   const char* jni_end_shorty;
     89   if (reference_return && is_synchronized) {
     90     jni_end_shorty = "ILL";
     91   } else if (reference_return) {
     92     jni_end_shorty = "IL";
     93   } else if (is_synchronized) {
     94     jni_end_shorty = "VL";
     95   } else {
     96     jni_end_shorty = "V";
     97   }
     98 
     99   std::unique_ptr<JniCallingConvention> end_jni_conv(JniCallingConvention::Create(
    100       &arena, is_static, is_synchronized, jni_end_shorty, instruction_set));
    101 
    102   // Assembler that holds generated instructions
    103   std::unique_ptr<Assembler> jni_asm(
    104       Assembler::Create(&arena, instruction_set, instruction_set_features));
    105   jni_asm->cfi().SetEnabled(driver->GetCompilerOptions().GenerateAnyDebugInfo());
    106 
    107   // Offsets into data structures
    108   // TODO: if cross compiling these offsets are for the host not the target
    109   const Offset functions(OFFSETOF_MEMBER(JNIEnvExt, functions));
    110   const Offset monitor_enter(OFFSETOF_MEMBER(JNINativeInterface, MonitorEnter));
    111   const Offset monitor_exit(OFFSETOF_MEMBER(JNINativeInterface, MonitorExit));
    112 
    113   // 1. Build the frame saving all callee saves
    114   const size_t frame_size(main_jni_conv->FrameSize());
    115   const std::vector<ManagedRegister>& callee_save_regs = main_jni_conv->CalleeSaveRegisters();
    116   __ BuildFrame(frame_size, mr_conv->MethodRegister(), callee_save_regs, mr_conv->EntrySpills());
    117   DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(frame_size));
    118 
    119   // 2. Set up the HandleScope
    120   mr_conv->ResetIterator(FrameOffset(frame_size));
    121   main_jni_conv->ResetIterator(FrameOffset(0));
    122   __ StoreImmediateToFrame(main_jni_conv->HandleScopeNumRefsOffset(),
    123                            main_jni_conv->ReferenceCount(),
    124                            mr_conv->InterproceduralScratchRegister());
    125 
    126   if (is_64_bit_target) {
    127     __ CopyRawPtrFromThread64(main_jni_conv->HandleScopeLinkOffset(),
    128                               Thread::TopHandleScopeOffset<8>(),
    129                               mr_conv->InterproceduralScratchRegister());
    130     __ StoreStackOffsetToThread64(Thread::TopHandleScopeOffset<8>(),
    131                                   main_jni_conv->HandleScopeOffset(),
    132                                   mr_conv->InterproceduralScratchRegister());
    133   } else {
    134     __ CopyRawPtrFromThread32(main_jni_conv->HandleScopeLinkOffset(),
    135                               Thread::TopHandleScopeOffset<4>(),
    136                               mr_conv->InterproceduralScratchRegister());
    137     __ StoreStackOffsetToThread32(Thread::TopHandleScopeOffset<4>(),
    138                                   main_jni_conv->HandleScopeOffset(),
    139                                   mr_conv->InterproceduralScratchRegister());
    140   }
    141 
    142   // 3. Place incoming reference arguments into handle scope
    143   main_jni_conv->Next();  // Skip JNIEnv*
    144   // 3.5. Create Class argument for static methods out of passed method
    145   if (is_static) {
    146     FrameOffset handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
    147     // Check handle scope offset is within frame
    148     CHECK_LT(handle_scope_offset.Uint32Value(), frame_size);
    149     // Note this LoadRef() doesn't need heap unpoisoning since it's from the ArtMethod.
    150     // Note this LoadRef() does not include read barrier. It will be handled below.
    151     __ LoadRef(main_jni_conv->InterproceduralScratchRegister(),
    152                mr_conv->MethodRegister(), ArtMethod::DeclaringClassOffset(), false);
    153     __ VerifyObject(main_jni_conv->InterproceduralScratchRegister(), false);
    154     __ StoreRef(handle_scope_offset, main_jni_conv->InterproceduralScratchRegister());
    155     main_jni_conv->Next();  // in handle scope so move to next argument
    156   }
    157   while (mr_conv->HasNext()) {
    158     CHECK(main_jni_conv->HasNext());
    159     bool ref_param = main_jni_conv->IsCurrentParamAReference();
    160     CHECK(!ref_param || mr_conv->IsCurrentParamAReference());
    161     // References need placing in handle scope and the entry value passing
    162     if (ref_param) {
    163       // Compute handle scope entry, note null is placed in the handle scope but its boxed value
    164       // must be null.
    165       FrameOffset handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
    166       // Check handle scope offset is within frame and doesn't run into the saved segment state.
    167       CHECK_LT(handle_scope_offset.Uint32Value(), frame_size);
    168       CHECK_NE(handle_scope_offset.Uint32Value(),
    169                main_jni_conv->SavedLocalReferenceCookieOffset().Uint32Value());
    170       bool input_in_reg = mr_conv->IsCurrentParamInRegister();
    171       bool input_on_stack = mr_conv->IsCurrentParamOnStack();
    172       CHECK(input_in_reg || input_on_stack);
    173 
    174       if (input_in_reg) {
    175         ManagedRegister in_reg  =  mr_conv->CurrentParamRegister();
    176         __ VerifyObject(in_reg, mr_conv->IsCurrentArgPossiblyNull());
    177         __ StoreRef(handle_scope_offset, in_reg);
    178       } else if (input_on_stack) {
    179         FrameOffset in_off  = mr_conv->CurrentParamStackOffset();
    180         __ VerifyObject(in_off, mr_conv->IsCurrentArgPossiblyNull());
    181         __ CopyRef(handle_scope_offset, in_off,
    182                    mr_conv->InterproceduralScratchRegister());
    183       }
    184     }
    185     mr_conv->Next();
    186     main_jni_conv->Next();
    187   }
    188 
    189   // 4. Write out the end of the quick frames.
    190   if (is_64_bit_target) {
    191     __ StoreStackPointerToThread64(Thread::TopOfManagedStackOffset<8>());
    192   } else {
    193     __ StoreStackPointerToThread32(Thread::TopOfManagedStackOffset<4>());
    194   }
    195 
    196   // 5. Move frame down to allow space for out going args.
    197   const size_t main_out_arg_size = main_jni_conv->OutArgSize();
    198   size_t current_out_arg_size = main_out_arg_size;
    199   __ IncreaseFrameSize(main_out_arg_size);
    200 
    201   // Call the read barrier for the declaring class loaded from the method for a static call.
    202   // Note that we always have outgoing param space available for at least two params.
    203   if (kUseReadBarrier && is_static) {
    204     ThreadOffset<4> read_barrier32 = QUICK_ENTRYPOINT_OFFSET(4, pReadBarrierJni);
    205     ThreadOffset<8> read_barrier64 = QUICK_ENTRYPOINT_OFFSET(8, pReadBarrierJni);
    206     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    207     main_jni_conv->Next();  // Skip JNIEnv.
    208     FrameOffset class_handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
    209     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    210     // Pass the handle for the class as the first argument.
    211     if (main_jni_conv->IsCurrentParamOnStack()) {
    212       FrameOffset out_off = main_jni_conv->CurrentParamStackOffset();
    213       __ CreateHandleScopeEntry(out_off, class_handle_scope_offset,
    214                          mr_conv->InterproceduralScratchRegister(),
    215                          false);
    216     } else {
    217       ManagedRegister out_reg = main_jni_conv->CurrentParamRegister();
    218       __ CreateHandleScopeEntry(out_reg, class_handle_scope_offset,
    219                          ManagedRegister::NoRegister(), false);
    220     }
    221     main_jni_conv->Next();
    222     // Pass the current thread as the second argument and call.
    223     if (main_jni_conv->IsCurrentParamInRegister()) {
    224       __ GetCurrentThread(main_jni_conv->CurrentParamRegister());
    225       if (is_64_bit_target) {
    226         __ Call(main_jni_conv->CurrentParamRegister(), Offset(read_barrier64),
    227                 main_jni_conv->InterproceduralScratchRegister());
    228       } else {
    229         __ Call(main_jni_conv->CurrentParamRegister(), Offset(read_barrier32),
    230                 main_jni_conv->InterproceduralScratchRegister());
    231       }
    232     } else {
    233       __ GetCurrentThread(main_jni_conv->CurrentParamStackOffset(),
    234                           main_jni_conv->InterproceduralScratchRegister());
    235       if (is_64_bit_target) {
    236         __ CallFromThread64(read_barrier64, main_jni_conv->InterproceduralScratchRegister());
    237       } else {
    238         __ CallFromThread32(read_barrier32, main_jni_conv->InterproceduralScratchRegister());
    239       }
    240     }
    241     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));  // Reset.
    242   }
    243 
    244   // 6. Call into appropriate JniMethodStart passing Thread* so that transition out of Runnable
    245   //    can occur. The result is the saved JNI local state that is restored by the exit call. We
    246   //    abuse the JNI calling convention here, that is guaranteed to support passing 2 pointer
    247   //    arguments.
    248   ThreadOffset<4> jni_start32 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(4, pJniMethodStartSynchronized)
    249                                                 : QUICK_ENTRYPOINT_OFFSET(4, pJniMethodStart);
    250   ThreadOffset<8> jni_start64 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(8, pJniMethodStartSynchronized)
    251                                                 : QUICK_ENTRYPOINT_OFFSET(8, pJniMethodStart);
    252   main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    253   FrameOffset locked_object_handle_scope_offset(0);
    254   if (is_synchronized) {
    255     // Pass object for locking.
    256     main_jni_conv->Next();  // Skip JNIEnv.
    257     locked_object_handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
    258     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    259     if (main_jni_conv->IsCurrentParamOnStack()) {
    260       FrameOffset out_off = main_jni_conv->CurrentParamStackOffset();
    261       __ CreateHandleScopeEntry(out_off, locked_object_handle_scope_offset,
    262                                 mr_conv->InterproceduralScratchRegister(), false);
    263     } else {
    264       ManagedRegister out_reg = main_jni_conv->CurrentParamRegister();
    265       __ CreateHandleScopeEntry(out_reg, locked_object_handle_scope_offset,
    266                                 ManagedRegister::NoRegister(), false);
    267     }
    268     main_jni_conv->Next();
    269   }
    270   if (main_jni_conv->IsCurrentParamInRegister()) {
    271     __ GetCurrentThread(main_jni_conv->CurrentParamRegister());
    272     if (is_64_bit_target) {
    273       __ Call(main_jni_conv->CurrentParamRegister(), Offset(jni_start64),
    274               main_jni_conv->InterproceduralScratchRegister());
    275     } else {
    276       __ Call(main_jni_conv->CurrentParamRegister(), Offset(jni_start32),
    277               main_jni_conv->InterproceduralScratchRegister());
    278     }
    279   } else {
    280     __ GetCurrentThread(main_jni_conv->CurrentParamStackOffset(),
    281                         main_jni_conv->InterproceduralScratchRegister());
    282     if (is_64_bit_target) {
    283       __ CallFromThread64(jni_start64, main_jni_conv->InterproceduralScratchRegister());
    284     } else {
    285       __ CallFromThread32(jni_start32, main_jni_conv->InterproceduralScratchRegister());
    286     }
    287   }
    288   if (is_synchronized) {  // Check for exceptions from monitor enter.
    289     __ ExceptionPoll(main_jni_conv->InterproceduralScratchRegister(), main_out_arg_size);
    290   }
    291   FrameOffset saved_cookie_offset = main_jni_conv->SavedLocalReferenceCookieOffset();
    292   __ Store(saved_cookie_offset, main_jni_conv->IntReturnRegister(), 4);
    293 
    294   // 7. Iterate over arguments placing values from managed calling convention in
    295   //    to the convention required for a native call (shuffling). For references
    296   //    place an index/pointer to the reference after checking whether it is
    297   //    null (which must be encoded as null).
    298   //    Note: we do this prior to materializing the JNIEnv* and static's jclass to
    299   //    give as many free registers for the shuffle as possible.
    300   mr_conv->ResetIterator(FrameOffset(frame_size + main_out_arg_size));
    301   uint32_t args_count = 0;
    302   while (mr_conv->HasNext()) {
    303     args_count++;
    304     mr_conv->Next();
    305   }
    306 
    307   // Do a backward pass over arguments, so that the generated code will be "mov
    308   // R2, R3; mov R1, R2" instead of "mov R1, R2; mov R2, R3."
    309   // TODO: A reverse iterator to improve readability.
    310   for (uint32_t i = 0; i < args_count; ++i) {
    311     mr_conv->ResetIterator(FrameOffset(frame_size + main_out_arg_size));
    312     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    313     main_jni_conv->Next();  // Skip JNIEnv*.
    314     if (is_static) {
    315       main_jni_conv->Next();  // Skip Class for now.
    316     }
    317     // Skip to the argument we're interested in.
    318     for (uint32_t j = 0; j < args_count - i - 1; ++j) {
    319       mr_conv->Next();
    320       main_jni_conv->Next();
    321     }
    322     CopyParameter(jni_asm.get(), mr_conv.get(), main_jni_conv.get(), frame_size, main_out_arg_size);
    323   }
    324   if (is_static) {
    325     // Create argument for Class
    326     mr_conv->ResetIterator(FrameOffset(frame_size + main_out_arg_size));
    327     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    328     main_jni_conv->Next();  // Skip JNIEnv*
    329     FrameOffset handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
    330     if (main_jni_conv->IsCurrentParamOnStack()) {
    331       FrameOffset out_off = main_jni_conv->CurrentParamStackOffset();
    332       __ CreateHandleScopeEntry(out_off, handle_scope_offset,
    333                          mr_conv->InterproceduralScratchRegister(),
    334                          false);
    335     } else {
    336       ManagedRegister out_reg = main_jni_conv->CurrentParamRegister();
    337       __ CreateHandleScopeEntry(out_reg, handle_scope_offset,
    338                          ManagedRegister::NoRegister(), false);
    339     }
    340   }
    341 
    342   // 8. Create 1st argument, the JNI environment ptr.
    343   main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
    344   // Register that will hold local indirect reference table
    345   if (main_jni_conv->IsCurrentParamInRegister()) {
    346     ManagedRegister jni_env = main_jni_conv->CurrentParamRegister();
    347     DCHECK(!jni_env.Equals(main_jni_conv->InterproceduralScratchRegister()));
    348     if (is_64_bit_target) {
    349       __ LoadRawPtrFromThread64(jni_env, Thread::JniEnvOffset<8>());
    350     } else {
    351       __ LoadRawPtrFromThread32(jni_env, Thread::JniEnvOffset<4>());
    352     }
    353   } else {
    354     FrameOffset jni_env = main_jni_conv->CurrentParamStackOffset();
    355     if (is_64_bit_target) {
    356       __ CopyRawPtrFromThread64(jni_env, Thread::JniEnvOffset<8>(),
    357                                 main_jni_conv->InterproceduralScratchRegister());
    358     } else {
    359       __ CopyRawPtrFromThread32(jni_env, Thread::JniEnvOffset<4>(),
    360                                 main_jni_conv->InterproceduralScratchRegister());
    361     }
    362   }
    363 
    364   // 9. Plant call to native code associated with method.
    365   MemberOffset jni_entrypoint_offset = ArtMethod::EntryPointFromJniOffset(
    366       InstructionSetPointerSize(instruction_set));
    367   __ Call(main_jni_conv->MethodStackOffset(), jni_entrypoint_offset,
    368           mr_conv->InterproceduralScratchRegister());
    369 
    370   // 10. Fix differences in result widths.
    371   if (main_jni_conv->RequiresSmallResultTypeExtension()) {
    372     if (main_jni_conv->GetReturnType() == Primitive::kPrimByte ||
    373         main_jni_conv->GetReturnType() == Primitive::kPrimShort) {
    374       __ SignExtend(main_jni_conv->ReturnRegister(),
    375                     Primitive::ComponentSize(main_jni_conv->GetReturnType()));
    376     } else if (main_jni_conv->GetReturnType() == Primitive::kPrimBoolean ||
    377                main_jni_conv->GetReturnType() == Primitive::kPrimChar) {
    378       __ ZeroExtend(main_jni_conv->ReturnRegister(),
    379                     Primitive::ComponentSize(main_jni_conv->GetReturnType()));
    380     }
    381   }
    382 
    383   // 11. Save return value
    384   FrameOffset return_save_location = main_jni_conv->ReturnValueSaveLocation();
    385   if (main_jni_conv->SizeOfReturnValue() != 0 && !reference_return) {
    386     if ((instruction_set == kMips || instruction_set == kMips64) &&
    387         main_jni_conv->GetReturnType() == Primitive::kPrimDouble &&
    388         return_save_location.Uint32Value() % 8 != 0) {
    389       // Ensure doubles are 8-byte aligned for MIPS
    390       return_save_location = FrameOffset(return_save_location.Uint32Value() + kMipsPointerSize);
    391     }
    392     CHECK_LT(return_save_location.Uint32Value(), frame_size + main_out_arg_size);
    393     __ Store(return_save_location, main_jni_conv->ReturnRegister(), main_jni_conv->SizeOfReturnValue());
    394   }
    395 
    396   // Increase frame size for out args if needed by the end_jni_conv.
    397   const size_t end_out_arg_size = end_jni_conv->OutArgSize();
    398   if (end_out_arg_size > current_out_arg_size) {
    399     size_t out_arg_size_diff = end_out_arg_size - current_out_arg_size;
    400     current_out_arg_size = end_out_arg_size;
    401     __ IncreaseFrameSize(out_arg_size_diff);
    402     saved_cookie_offset = FrameOffset(saved_cookie_offset.SizeValue() + out_arg_size_diff);
    403     locked_object_handle_scope_offset =
    404         FrameOffset(locked_object_handle_scope_offset.SizeValue() + out_arg_size_diff);
    405     return_save_location = FrameOffset(return_save_location.SizeValue() + out_arg_size_diff);
    406   }
    407   //     thread.
    408   end_jni_conv->ResetIterator(FrameOffset(end_out_arg_size));
    409   ThreadOffset<4> jni_end32(-1);
    410   ThreadOffset<8> jni_end64(-1);
    411   if (reference_return) {
    412     // Pass result.
    413     jni_end32 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(4, pJniMethodEndWithReferenceSynchronized)
    414                                 : QUICK_ENTRYPOINT_OFFSET(4, pJniMethodEndWithReference);
    415     jni_end64 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(8, pJniMethodEndWithReferenceSynchronized)
    416                                 : QUICK_ENTRYPOINT_OFFSET(8, pJniMethodEndWithReference);
    417     SetNativeParameter(jni_asm.get(), end_jni_conv.get(), end_jni_conv->ReturnRegister());
    418     end_jni_conv->Next();
    419   } else {
    420     jni_end32 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(4, pJniMethodEndSynchronized)
    421                                 : QUICK_ENTRYPOINT_OFFSET(4, pJniMethodEnd);
    422     jni_end64 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(8, pJniMethodEndSynchronized)
    423                                 : QUICK_ENTRYPOINT_OFFSET(8, pJniMethodEnd);
    424   }
    425   // Pass saved local reference state.
    426   if (end_jni_conv->IsCurrentParamOnStack()) {
    427     FrameOffset out_off = end_jni_conv->CurrentParamStackOffset();
    428     __ Copy(out_off, saved_cookie_offset, end_jni_conv->InterproceduralScratchRegister(), 4);
    429   } else {
    430     ManagedRegister out_reg = end_jni_conv->CurrentParamRegister();
    431     __ Load(out_reg, saved_cookie_offset, 4);
    432   }
    433   end_jni_conv->Next();
    434   if (is_synchronized) {
    435     // Pass object for unlocking.
    436     if (end_jni_conv->IsCurrentParamOnStack()) {
    437       FrameOffset out_off = end_jni_conv->CurrentParamStackOffset();
    438       __ CreateHandleScopeEntry(out_off, locked_object_handle_scope_offset,
    439                          end_jni_conv->InterproceduralScratchRegister(),
    440                          false);
    441     } else {
    442       ManagedRegister out_reg = end_jni_conv->CurrentParamRegister();
    443       __ CreateHandleScopeEntry(out_reg, locked_object_handle_scope_offset,
    444                          ManagedRegister::NoRegister(), false);
    445     }
    446     end_jni_conv->Next();
    447   }
    448   if (end_jni_conv->IsCurrentParamInRegister()) {
    449     __ GetCurrentThread(end_jni_conv->CurrentParamRegister());
    450     if (is_64_bit_target) {
    451       __ Call(end_jni_conv->CurrentParamRegister(), Offset(jni_end64),
    452               end_jni_conv->InterproceduralScratchRegister());
    453     } else {
    454       __ Call(end_jni_conv->CurrentParamRegister(), Offset(jni_end32),
    455               end_jni_conv->InterproceduralScratchRegister());
    456     }
    457   } else {
    458     __ GetCurrentThread(end_jni_conv->CurrentParamStackOffset(),
    459                         end_jni_conv->InterproceduralScratchRegister());
    460     if (is_64_bit_target) {
    461       __ CallFromThread64(ThreadOffset<8>(jni_end64), end_jni_conv->InterproceduralScratchRegister());
    462     } else {
    463       __ CallFromThread32(ThreadOffset<4>(jni_end32), end_jni_conv->InterproceduralScratchRegister());
    464     }
    465   }
    466 
    467   // 13. Reload return value
    468   if (main_jni_conv->SizeOfReturnValue() != 0 && !reference_return) {
    469     __ Load(mr_conv->ReturnRegister(), return_save_location, mr_conv->SizeOfReturnValue());
    470   }
    471 
    472   // 14. Move frame up now we're done with the out arg space.
    473   __ DecreaseFrameSize(current_out_arg_size);
    474 
    475   // 15. Process pending exceptions from JNI call or monitor exit.
    476   __ ExceptionPoll(main_jni_conv->InterproceduralScratchRegister(), 0);
    477 
    478   // 16. Remove activation - need to restore callee save registers since the GC may have changed
    479   //     them.
    480   DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(frame_size));
    481   __ RemoveFrame(frame_size, callee_save_regs);
    482   DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(frame_size));
    483 
    484   // 17. Finalize code generation
    485   __ FinalizeCode();
    486   size_t cs = __ CodeSize();
    487   std::vector<uint8_t> managed_code(cs);
    488   MemoryRegion code(&managed_code[0], managed_code.size());
    489   __ FinalizeInstructions(code);
    490 
    491   return CompiledMethod::SwapAllocCompiledMethod(driver,
    492                                                  instruction_set,
    493                                                  ArrayRef<const uint8_t>(managed_code),
    494                                                  frame_size,
    495                                                  main_jni_conv->CoreSpillMask(),
    496                                                  main_jni_conv->FpSpillMask(),
    497                                                  ArrayRef<const SrcMapElem>(),
    498                                                  ArrayRef<const uint8_t>(),  // vmap_table.
    499                                                  ArrayRef<const uint8_t>(*jni_asm->cfi().data()),
    500                                                  ArrayRef<const LinkerPatch>());
    501 }
    502 
    503 // Copy a single parameter from the managed to the JNI calling convention.
    504 static void CopyParameter(Assembler* jni_asm,
    505                           ManagedRuntimeCallingConvention* mr_conv,
    506                           JniCallingConvention* jni_conv,
    507                           size_t frame_size, size_t out_arg_size) {
    508   bool input_in_reg = mr_conv->IsCurrentParamInRegister();
    509   bool output_in_reg = jni_conv->IsCurrentParamInRegister();
    510   FrameOffset handle_scope_offset(0);
    511   bool null_allowed = false;
    512   bool ref_param = jni_conv->IsCurrentParamAReference();
    513   CHECK(!ref_param || mr_conv->IsCurrentParamAReference());
    514   // input may be in register, on stack or both - but not none!
    515   CHECK(input_in_reg || mr_conv->IsCurrentParamOnStack());
    516   if (output_in_reg) {  // output shouldn't straddle registers and stack
    517     CHECK(!jni_conv->IsCurrentParamOnStack());
    518   } else {
    519     CHECK(jni_conv->IsCurrentParamOnStack());
    520   }
    521   // References need placing in handle scope and the entry address passing.
    522   if (ref_param) {
    523     null_allowed = mr_conv->IsCurrentArgPossiblyNull();
    524     // Compute handle scope offset. Note null is placed in the handle scope but the jobject
    525     // passed to the native code must be null (not a pointer into the handle scope
    526     // as with regular references).
    527     handle_scope_offset = jni_conv->CurrentParamHandleScopeEntryOffset();
    528     // Check handle scope offset is within frame.
    529     CHECK_LT(handle_scope_offset.Uint32Value(), (frame_size + out_arg_size));
    530   }
    531   if (input_in_reg && output_in_reg) {
    532     ManagedRegister in_reg = mr_conv->CurrentParamRegister();
    533     ManagedRegister out_reg = jni_conv->CurrentParamRegister();
    534     if (ref_param) {
    535       __ CreateHandleScopeEntry(out_reg, handle_scope_offset, in_reg, null_allowed);
    536     } else {
    537       if (!mr_conv->IsCurrentParamOnStack()) {
    538         // regular non-straddling move
    539         __ Move(out_reg, in_reg, mr_conv->CurrentParamSize());
    540       } else {
    541         UNIMPLEMENTED(FATAL);  // we currently don't expect to see this case
    542       }
    543     }
    544   } else if (!input_in_reg && !output_in_reg) {
    545     FrameOffset out_off = jni_conv->CurrentParamStackOffset();
    546     if (ref_param) {
    547       __ CreateHandleScopeEntry(out_off, handle_scope_offset, mr_conv->InterproceduralScratchRegister(),
    548                          null_allowed);
    549     } else {
    550       FrameOffset in_off = mr_conv->CurrentParamStackOffset();
    551       size_t param_size = mr_conv->CurrentParamSize();
    552       CHECK_EQ(param_size, jni_conv->CurrentParamSize());
    553       __ Copy(out_off, in_off, mr_conv->InterproceduralScratchRegister(), param_size);
    554     }
    555   } else if (!input_in_reg && output_in_reg) {
    556     FrameOffset in_off = mr_conv->CurrentParamStackOffset();
    557     ManagedRegister out_reg = jni_conv->CurrentParamRegister();
    558     // Check that incoming stack arguments are above the current stack frame.
    559     CHECK_GT(in_off.Uint32Value(), frame_size);
    560     if (ref_param) {
    561       __ CreateHandleScopeEntry(out_reg, handle_scope_offset, ManagedRegister::NoRegister(), null_allowed);
    562     } else {
    563       size_t param_size = mr_conv->CurrentParamSize();
    564       CHECK_EQ(param_size, jni_conv->CurrentParamSize());
    565       __ Load(out_reg, in_off, param_size);
    566     }
    567   } else {
    568     CHECK(input_in_reg && !output_in_reg);
    569     ManagedRegister in_reg = mr_conv->CurrentParamRegister();
    570     FrameOffset out_off = jni_conv->CurrentParamStackOffset();
    571     // Check outgoing argument is within frame
    572     CHECK_LT(out_off.Uint32Value(), frame_size);
    573     if (ref_param) {
    574       // TODO: recycle value in in_reg rather than reload from handle scope
    575       __ CreateHandleScopeEntry(out_off, handle_scope_offset, mr_conv->InterproceduralScratchRegister(),
    576                          null_allowed);
    577     } else {
    578       size_t param_size = mr_conv->CurrentParamSize();
    579       CHECK_EQ(param_size, jni_conv->CurrentParamSize());
    580       if (!mr_conv->IsCurrentParamOnStack()) {
    581         // regular non-straddling store
    582         __ Store(out_off, in_reg, param_size);
    583       } else {
    584         // store where input straddles registers and stack
    585         CHECK_EQ(param_size, 8u);
    586         FrameOffset in_off = mr_conv->CurrentParamStackOffset();
    587         __ StoreSpanning(out_off, in_reg, in_off, mr_conv->InterproceduralScratchRegister());
    588       }
    589     }
    590   }
    591 }
    592 
    593 static void SetNativeParameter(Assembler* jni_asm,
    594                                JniCallingConvention* jni_conv,
    595                                ManagedRegister in_reg) {
    596   if (jni_conv->IsCurrentParamOnStack()) {
    597     FrameOffset dest = jni_conv->CurrentParamStackOffset();
    598     __ StoreRawPtr(dest, in_reg);
    599   } else {
    600     if (!jni_conv->CurrentParamRegister().Equals(in_reg)) {
    601       __ Move(jni_conv->CurrentParamRegister(), in_reg, jni_conv->CurrentParamSize());
    602     }
    603   }
    604 }
    605 
    606 CompiledMethod* ArtQuickJniCompileMethod(CompilerDriver* compiler, uint32_t access_flags,
    607                                          uint32_t method_idx, const DexFile& dex_file) {
    608   return ArtJniCompileMethodInternal(compiler, access_flags, method_idx, dex_file);
    609 }
    610 
    611 }  // namespace art
    612