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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "jni_compiler.h"
#include <algorithm>
#include <fstream>
#include <ios>
#include <memory>
#include <vector>
#include "art_method.h"
#include "base/arena_allocator.h"
#include "base/arena_containers.h"
#include "base/enums.h"
#include "base/logging.h" // For VLOG.
#include "base/macros.h"
#include "base/memory_region.h"
#include "base/utils.h"
#include "calling_convention.h"
#include "class_linker.h"
#include "dwarf/debug_frame_opcode_writer.h"
#include "dex/dex_file-inl.h"
#include "driver/compiler_options.h"
#include "entrypoints/quick/quick_entrypoints.h"
#include "instrumentation.h"
#include "jni/jni_env_ext.h"
#include "runtime.h"
#include "thread.h"
#include "utils/arm/managed_register_arm.h"
#include "utils/arm64/managed_register_arm64.h"
#include "utils/assembler.h"
#include "utils/jni_macro_assembler.h"
#include "utils/managed_register.h"
#include "utils/x86/managed_register_x86.h"
#define __ jni_asm->
namespace art HIDDEN {
constexpr size_t kIRTCookieSize = JniCallingConvention::SavedLocalReferenceCookieSize();
template <PointerSize kPointerSize>
static void PushLocalReferenceFrame(JNIMacroAssembler<kPointerSize>* jni_asm,
ManagedRegister jni_env_reg,
ManagedRegister saved_cookie_reg,
ManagedRegister temp_reg);
template <PointerSize kPointerSize>
static void PopLocalReferenceFrame(JNIMacroAssembler<kPointerSize>* jni_asm,
ManagedRegister jni_env_reg,
ManagedRegister saved_cookie_reg,
ManagedRegister temp_reg);
template <PointerSize kPointerSize>
static void SetNativeParameter(JNIMacroAssembler<kPointerSize>* jni_asm,
JniCallingConvention* jni_conv,
ManagedRegister in_reg);
template <PointerSize kPointerSize>
static void CallDecodeReferenceResult(JNIMacroAssembler<kPointerSize>* jni_asm,
JniCallingConvention* jni_conv,
ManagedRegister mr_return_reg,
size_t main_out_arg_size);
template <PointerSize kPointerSize>
static std::unique_ptr<JNIMacroAssembler<kPointerSize>> GetMacroAssembler(
ArenaAllocator* allocator, InstructionSet isa, const InstructionSetFeatures* features) {
return JNIMacroAssembler<kPointerSize>::Create(allocator, isa, features);
}
// Generate the JNI bridge for the given method, general contract:
// - Arguments are in the managed runtime format, either on stack or in
// registers, a reference to the method object is supplied as part of this
// convention.
//
template <PointerSize kPointerSize>
static JniCompiledMethod ArtJniCompileMethodInternal(const CompilerOptions& compiler_options,
uint32_t access_flags,
uint32_t method_idx,
const DexFile& dex_file,
ArenaAllocator* allocator) {
constexpr size_t kRawPointerSize = static_cast<size_t>(kPointerSize);
const bool is_native = (access_flags & kAccNative) != 0;
CHECK(is_native);
const bool is_static = (access_flags & kAccStatic) != 0;
const bool is_synchronized = (access_flags & kAccSynchronized) != 0;
const char* shorty = dex_file.GetMethodShorty(dex_file.GetMethodId(method_idx));
InstructionSet instruction_set = compiler_options.GetInstructionSet();
const InstructionSetFeatures* instruction_set_features =
compiler_options.GetInstructionSetFeatures();
// i.e. if the method was annotated with @FastNative
const bool is_fast_native = (access_flags & kAccFastNative) != 0u;
// i.e. if the method was annotated with @CriticalNative
const bool is_critical_native = (access_flags & kAccCriticalNative) != 0u;
bool is_debuggable = compiler_options.GetDebuggable();
bool needs_entry_exit_hooks = is_debuggable && compiler_options.IsJitCompiler();
// We don't support JITing stubs for critical native methods in debuggable runtimes yet.
// TODO(mythria): Add support required for calling method entry / exit hooks from critical native
// methods.
DCHECK_IMPLIES(needs_entry_exit_hooks, !is_critical_native);
// The fast-path for decoding a reference skips CheckJNI checks, so we do not inline the
// decoding in debug build or for debuggable apps (both cases enable CheckJNI by default).
bool inline_decode_reference = !kIsDebugBuild && !is_debuggable;
// When walking the stack the top frame doesn't have a pc associated with it. We then depend on
// the invariant that we don't have JITed code when AOT code is available. In debuggable runtimes
// this invariant doesn't hold. So we tag the SP for JITed code to indentify if we are executing
// JITed code or AOT code. Since tagging involves additional instructions we tag only in
// debuggable runtimes.
bool should_tag_sp = needs_entry_exit_hooks;
VLOG(jni) << "JniCompile: Method :: "
<< dex_file.PrettyMethod(method_idx, /* with signature */ true)
<< " :: access_flags = " << std::hex << access_flags << std::dec;
if (UNLIKELY(is_fast_native)) {
VLOG(jni) << "JniCompile: Fast native method detected :: "
<< dex_file.PrettyMethod(method_idx, /* with signature */ true);
}
if (UNLIKELY(is_critical_native)) {
VLOG(jni) << "JniCompile: Critical native method detected :: "
<< dex_file.PrettyMethod(method_idx, /* with signature */ true);
}
if (kIsDebugBuild) {
// Don't allow both @FastNative and @CriticalNative. They are mutually exclusive.
if (UNLIKELY(is_fast_native && is_critical_native)) {
LOG(FATAL) << "JniCompile: Method cannot be both @CriticalNative and @FastNative"
<< dex_file.PrettyMethod(method_idx, /* with_signature= */ true);
}
// @CriticalNative - extra checks:
// -- Don't allow virtual criticals
// -- Don't allow synchronized criticals
// -- Don't allow any objects as parameter or return value
if (UNLIKELY(is_critical_native)) {
CHECK(is_static)
<< "@CriticalNative functions cannot be virtual since that would "
<< "require passing a reference parameter (this), which is illegal "
<< dex_file.PrettyMethod(method_idx, /* with_signature= */ true);
CHECK(!is_synchronized)
<< "@CriticalNative functions cannot be synchronized since that would "
<< "require passing a (class and/or this) reference parameter, which is illegal "
<< dex_file.PrettyMethod(method_idx, /* with_signature= */ true);
for (size_t i = 0; i < strlen(shorty); ++i) {
CHECK_NE(Primitive::kPrimNot, Primitive::GetType(shorty[i]))
<< "@CriticalNative methods' shorty types must not have illegal references "
<< dex_file.PrettyMethod(method_idx, /* with_signature= */ true);
}
}
}
// Calling conventions used to iterate over parameters to method
std::unique_ptr<JniCallingConvention> main_jni_conv =
JniCallingConvention::Create(allocator,
is_static,
is_synchronized,
is_fast_native,
is_critical_native,
shorty,
instruction_set);
bool reference_return = main_jni_conv->IsReturnAReference();
std::unique_ptr<ManagedRuntimeCallingConvention> mr_conv(
ManagedRuntimeCallingConvention::Create(
allocator, is_static, is_synchronized, shorty, instruction_set));
// Assembler that holds generated instructions
std::unique_ptr<JNIMacroAssembler<kPointerSize>> jni_asm =
GetMacroAssembler<kPointerSize>(allocator, instruction_set, instruction_set_features);
jni_asm->cfi().SetEnabled(compiler_options.GenerateAnyDebugInfo());
jni_asm->SetEmitRunTimeChecksInDebugMode(compiler_options.EmitRunTimeChecksInDebugMode());
// 1. Build and register the native method frame.
// 1.1. Build the frame saving all callee saves, Method*, and PC return address.
// For @CriticalNative, this includes space for out args, otherwise just the managed frame.
const size_t managed_frame_size = main_jni_conv->FrameSize();
const size_t main_out_arg_size = main_jni_conv->OutFrameSize();
size_t current_frame_size = is_critical_native ? main_out_arg_size : managed_frame_size;
ManagedRegister method_register =
is_critical_native ? ManagedRegister::NoRegister() : mr_conv->MethodRegister();
ArrayRef<const ManagedRegister> callee_save_regs = main_jni_conv->CalleeSaveRegisters();
__ BuildFrame(current_frame_size, method_register, callee_save_regs);
DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(current_frame_size));
// 1.2. Check if we need to go to the slow path to emit the read barrier
// for the declaring class in the method for a static call.
// Skip this for @CriticalNative because we're not passing a `jclass` to the native method.
std::unique_ptr<JNIMacroLabel> jclass_read_barrier_slow_path;
std::unique_ptr<JNIMacroLabel> jclass_read_barrier_return;
if (gUseReadBarrier && is_static && LIKELY(!is_critical_native)) {
jclass_read_barrier_slow_path = __ CreateLabel();
jclass_read_barrier_return = __ CreateLabel();
// Check if gc_is_marking is set -- if it's not, we don't need a read barrier.
__ TestGcMarking(jclass_read_barrier_slow_path.get(), JNIMacroUnaryCondition::kNotZero);
// If marking, the slow path returns after the check.
__ Bind(jclass_read_barrier_return.get());
}
// 1.3 Spill reference register arguments.
constexpr FrameOffset kInvalidReferenceOffset =
JNIMacroAssembler<kPointerSize>::kInvalidReferenceOffset;
ArenaVector<ArgumentLocation> src_args(allocator->Adapter());
ArenaVector<ArgumentLocation> dest_args(allocator->Adapter());
ArenaVector<FrameOffset> refs(allocator->Adapter());
if (LIKELY(!is_critical_native)) {
mr_conv->ResetIterator(FrameOffset(current_frame_size));
for (; mr_conv->HasNext(); mr_conv->Next()) {
if (mr_conv->IsCurrentParamInRegister() && mr_conv->IsCurrentParamAReference()) {
// Spill the reference as raw data.
src_args.emplace_back(mr_conv->CurrentParamRegister(), kObjectReferenceSize);
dest_args.emplace_back(mr_conv->CurrentParamStackOffset(), kObjectReferenceSize);
refs.push_back(kInvalidReferenceOffset);
}
}
__ MoveArguments(ArrayRef<ArgumentLocation>(dest_args),
ArrayRef<ArgumentLocation>(src_args),
ArrayRef<FrameOffset>(refs));
}
// 1.4. Write out the end of the quick frames. After this, we can walk the stack.
// NOTE: @CriticalNative does not need to store the stack pointer to the thread
// because garbage collections are disabled within the execution of a
// @CriticalNative method.
if (LIKELY(!is_critical_native)) {
__ StoreStackPointerToThread(Thread::TopOfManagedStackOffset<kPointerSize>(), should_tag_sp);
}
// 1.5. Call any method entry hooks if required.
// For critical native methods, we don't JIT stubs in debuggable runtimes (see
// OptimizingCompiler::JitCompile).
// TODO(mythria): Add support to call method entry / exit hooks for critical native methods too.
std::unique_ptr<JNIMacroLabel> method_entry_hook_slow_path;
std::unique_ptr<JNIMacroLabel> method_entry_hook_return;
if (UNLIKELY(needs_entry_exit_hooks)) {
uint64_t address = reinterpret_cast64<uint64_t>(Runtime::Current()->GetInstrumentation());
int offset = instrumentation::Instrumentation::HaveMethodEntryListenersOffset().Int32Value();
method_entry_hook_slow_path = __ CreateLabel();
method_entry_hook_return = __ CreateLabel();
__ TestByteAndJumpIfNotZero(address + offset, method_entry_hook_slow_path.get());
__ Bind(method_entry_hook_return.get());
}
// 2. Lock the object (if synchronized) and transition out of Runnable (if normal native).
// 2.1. Lock the synchronization object (`this` or class) for synchronized methods.
if (UNLIKELY(is_synchronized)) {
// We are using a custom calling convention for locking where the assembly thunk gets
// the object to lock in a register (even on x86), it can use callee-save registers
// as temporaries (they were saved above) and must preserve argument registers.
ManagedRegister to_lock = main_jni_conv->LockingArgumentRegister();
if (is_static) {
// Pass the declaring class. It was already marked if needed.
DCHECK_EQ(ArtMethod::DeclaringClassOffset().SizeValue(), 0u);
__ Load(to_lock, method_register, MemberOffset(0u), kObjectReferenceSize);
} else {
// Pass the `this` argument.
mr_conv->ResetIterator(FrameOffset(current_frame_size));
if (mr_conv->IsCurrentParamInRegister()) {
__ Move(to_lock, mr_conv->CurrentParamRegister(), kObjectReferenceSize);
} else {
__ Load(to_lock, mr_conv->CurrentParamStackOffset(), kObjectReferenceSize);
}
}
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pJniLockObject));
}
// 2.2. Transition from Runnable to Suspended.
// Managed callee-saves were already saved, so these registers are now available.
ArrayRef<const ManagedRegister> callee_save_scratch_regs = UNLIKELY(is_critical_native)
? ArrayRef<const ManagedRegister>()
: main_jni_conv->CalleeSaveScratchRegisters();
std::unique_ptr<JNIMacroLabel> transition_to_native_slow_path;
std::unique_ptr<JNIMacroLabel> transition_to_native_resume;
if (LIKELY(!is_critical_native && !is_fast_native)) {
transition_to_native_slow_path = __ CreateLabel();
transition_to_native_resume = __ CreateLabel();
__ TryToTransitionFromRunnableToNative(transition_to_native_slow_path.get(),
callee_save_scratch_regs);
__ Bind(transition_to_native_resume.get());
}
// 3. Push local reference frame.
// Skip this for @CriticalNative methods, they cannot use any references.
ManagedRegister jni_env_reg = ManagedRegister::NoRegister();
ManagedRegister saved_cookie_reg = ManagedRegister::NoRegister();
ManagedRegister callee_save_temp = ManagedRegister::NoRegister();
if (LIKELY(!is_critical_native)) {
// To pop the local reference frame later, we shall need the JNI environment pointer
// as well as the cookie, so we preserve them across calls in callee-save registers.
CHECK_GE(callee_save_scratch_regs.size(), 3u); // At least 3 for each supported architecture.
jni_env_reg = callee_save_scratch_regs[0];
saved_cookie_reg = __ CoreRegisterWithSize(callee_save_scratch_regs[1], kIRTCookieSize);
callee_save_temp = __ CoreRegisterWithSize(callee_save_scratch_regs[2], kIRTCookieSize);
// Load the JNI environment pointer.
__ LoadRawPtrFromThread(jni_env_reg, Thread::JniEnvOffset<kPointerSize>());
// Push the local reference frame.
PushLocalReferenceFrame<kPointerSize>(
jni_asm.get(), jni_env_reg, saved_cookie_reg, callee_save_temp);
}
// 4. Make the main native call.
// 4.1. Move frame down to allow space for out going args.
size_t current_out_arg_size = main_out_arg_size;
if (UNLIKELY(is_critical_native)) {
DCHECK_EQ(main_out_arg_size, current_frame_size);
} else {
__ IncreaseFrameSize(main_out_arg_size);
current_frame_size += main_out_arg_size;
}
// 4.2. Fill arguments except the `JNIEnv*`.
// Note: Non-null reference arguments in registers may point to the from-space if we
// took the slow-path for locking or transition to Native. However, we only need to
// compare them with null to construct `jobject`s, so we can still use them.
src_args.clear();
dest_args.clear();
refs.clear();
mr_conv->ResetIterator(FrameOffset(current_frame_size));
main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
if (UNLIKELY(is_critical_native)) {
// Move the method pointer to the hidden argument register.
// TODO: Pass this as the last argument, not first. Change ARM assembler
// not to expect all register destinations at the beginning.
src_args.emplace_back(mr_conv->MethodRegister(), kRawPointerSize);
dest_args.emplace_back(main_jni_conv->HiddenArgumentRegister(), kRawPointerSize);
refs.push_back(kInvalidReferenceOffset);
} else {
main_jni_conv->Next(); // Skip JNIEnv*.
FrameOffset method_offset(current_out_arg_size + mr_conv->MethodStackOffset().SizeValue());
if (!is_static || main_jni_conv->IsCurrentParamOnStack()) {
// The method shall not be available in the `jclass` argument register.
// Make sure it is available in `callee_save_temp` for the call below.
// (The old method register can be clobbered by argument moves.)
ManagedRegister new_method_reg = __ CoreRegisterWithSize(callee_save_temp, kRawPointerSize);
DCHECK(!method_register.IsNoRegister());
__ Move(new_method_reg, method_register, kRawPointerSize);
method_register = new_method_reg;
}
if (is_static) {
// For static methods, move/load the method to the `jclass` argument.
DCHECK_EQ(ArtMethod::DeclaringClassOffset().SizeValue(), 0u);
if (method_register.IsNoRegister()) {
DCHECK(main_jni_conv->IsCurrentParamInRegister());
src_args.emplace_back(method_offset, kRawPointerSize);
} else {
src_args.emplace_back(method_register, kRawPointerSize);
}
if (main_jni_conv->IsCurrentParamInRegister()) {
// The `jclass` argument becomes the new method register needed for the call.
method_register = main_jni_conv->CurrentParamRegister();
dest_args.emplace_back(method_register, kRawPointerSize);
} else {
dest_args.emplace_back(main_jni_conv->CurrentParamStackOffset(), kRawPointerSize);
}
refs.push_back(kInvalidReferenceOffset);
main_jni_conv->Next();
}
}
// Move normal arguments to their locations.
for (; mr_conv->HasNext(); mr_conv->Next(), main_jni_conv->Next()) {
DCHECK(main_jni_conv->HasNext());
static_assert(kObjectReferenceSize == 4u);
bool is_reference = mr_conv->IsCurrentParamAReference();
size_t src_size = (!is_reference && mr_conv->IsCurrentParamALongOrDouble()) ? 8u : 4u;
size_t dest_size = is_reference ? kRawPointerSize : src_size;
src_args.push_back(mr_conv->IsCurrentParamInRegister()
? ArgumentLocation(mr_conv->CurrentParamRegister(), src_size)
: ArgumentLocation(mr_conv->CurrentParamStackOffset(), src_size));
dest_args.push_back(main_jni_conv->IsCurrentParamInRegister()
? ArgumentLocation(main_jni_conv->CurrentParamRegister(), dest_size)
: ArgumentLocation(main_jni_conv->CurrentParamStackOffset(), dest_size));
refs.push_back(is_reference ? mr_conv->CurrentParamStackOffset() : kInvalidReferenceOffset);
}
DCHECK(!main_jni_conv->HasNext());
__ MoveArguments(ArrayRef<ArgumentLocation>(dest_args),
ArrayRef<ArgumentLocation>(src_args),
ArrayRef<FrameOffset>(refs));
// 4.3. Create 1st argument, the JNI environment ptr.
if (LIKELY(!is_critical_native)) {
main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
if (main_jni_conv->IsCurrentParamInRegister()) {
ManagedRegister jni_env_arg = main_jni_conv->CurrentParamRegister();
__ Move(jni_env_arg, jni_env_reg, kRawPointerSize);
} else {
FrameOffset jni_env_arg_offset = main_jni_conv->CurrentParamStackOffset();
__ Store(jni_env_arg_offset, jni_env_reg, kRawPointerSize);
}
}
// 4.4. Plant call to native code associated with method.
MemberOffset jni_entrypoint_offset =
ArtMethod::EntryPointFromJniOffset(InstructionSetPointerSize(instruction_set));
if (UNLIKELY(is_critical_native)) {
if (main_jni_conv->UseTailCall()) {
__ Jump(main_jni_conv->HiddenArgumentRegister(), jni_entrypoint_offset);
} else {
__ Call(main_jni_conv->HiddenArgumentRegister(), jni_entrypoint_offset);
}
} else {
DCHECK(method_register.IsRegister());
__ Call(method_register, jni_entrypoint_offset);
// We shall not need the method register anymore. And we may clobber it below
// if it's the `callee_save_temp`, so clear it here to make sure it's not used.
method_register = ManagedRegister::NoRegister();
}
// 4.5. Fix differences in result widths.
if (main_jni_conv->RequiresSmallResultTypeExtension()) {
DCHECK(main_jni_conv->HasSmallReturnType());
CHECK_IMPLIES(is_critical_native, !main_jni_conv->UseTailCall());
if (main_jni_conv->GetReturnType() == Primitive::kPrimByte ||
main_jni_conv->GetReturnType() == Primitive::kPrimShort) {
__ SignExtend(main_jni_conv->ReturnRegister(),
Primitive::ComponentSize(main_jni_conv->GetReturnType()));
} else {
CHECK(main_jni_conv->GetReturnType() == Primitive::kPrimBoolean ||
main_jni_conv->GetReturnType() == Primitive::kPrimChar);
__ ZeroExtend(main_jni_conv->ReturnRegister(),
Primitive::ComponentSize(main_jni_conv->GetReturnType()));
}
}
// 4.6. Move the JNI return register into the managed return register (if they don't match).
if (main_jni_conv->SizeOfReturnValue() != 0) {
ManagedRegister jni_return_reg = main_jni_conv->ReturnRegister();
ManagedRegister mr_return_reg = mr_conv->ReturnRegister();
// Check if the JNI return register matches the managed return register.
// If they differ, only then do we have to do anything about it.
// Otherwise the return value is already in the right place when we return.
if (!jni_return_reg.Equals(mr_return_reg)) {
CHECK_IMPLIES(is_critical_native, !main_jni_conv->UseTailCall());
// This is typically only necessary on ARM32 due to native being softfloat
// while managed is hardfloat.
// -- For example VMOV {r0, r1} -> D0; VMOV r0 -> S0.
__ Move(mr_return_reg, jni_return_reg, main_jni_conv->SizeOfReturnValue());
} else if (jni_return_reg.IsNoRegister() && mr_return_reg.IsNoRegister()) {
// Check that if the return value is passed on the stack for some reason,
// that the size matches.
CHECK_EQ(main_jni_conv->SizeOfReturnValue(), mr_conv->SizeOfReturnValue());
}
}
// 5. Transition to Runnable (if normal native).
// 5.1. Try transitioning to Runnable with a fast-path implementation.
// If fast-path fails, make a slow-path call to `JniMethodEnd()`.
std::unique_ptr<JNIMacroLabel> transition_to_runnable_slow_path;
std::unique_ptr<JNIMacroLabel> transition_to_runnable_resume;
if (LIKELY(!is_critical_native && !is_fast_native)) {
transition_to_runnable_slow_path = __ CreateLabel();
transition_to_runnable_resume = __ CreateLabel();
__ TryToTransitionFromNativeToRunnable(transition_to_runnable_slow_path.get(),
main_jni_conv->ArgumentScratchRegisters(),
mr_conv->ReturnRegister());
__ Bind(transition_to_runnable_resume.get());
}
// 5.2. For methods that return a reference, do an exception check before decoding the reference.
std::unique_ptr<JNIMacroLabel> exception_slow_path =
LIKELY(!is_critical_native) ? __ CreateLabel() : nullptr;
if (reference_return) {
DCHECK(!is_critical_native);
__ ExceptionPoll(exception_slow_path.get());
}
// 5.3. For @FastNative that returns a reference, do an early suspend check so that we
// do not need to encode the decoded reference in a stack map.
std::unique_ptr<JNIMacroLabel> suspend_check_slow_path =
UNLIKELY(is_fast_native) ? __ CreateLabel() : nullptr;
std::unique_ptr<JNIMacroLabel> suspend_check_resume =
UNLIKELY(is_fast_native) ? __ CreateLabel() : nullptr;
if (UNLIKELY(is_fast_native) && reference_return) {
__ SuspendCheck(suspend_check_slow_path.get());
__ Bind(suspend_check_resume.get());
}
// 5.4 For methods with reference return, decode the `jobject`, either directly
// or with a call to `JniDecodeReferenceResult()`.
std::unique_ptr<JNIMacroLabel> decode_reference_slow_path;
std::unique_ptr<JNIMacroLabel> decode_reference_resume;
if (reference_return) {
DCHECK(!is_critical_native);
if (inline_decode_reference) {
// Decode local and JNI transition references in the main path.
decode_reference_slow_path = __ CreateLabel();
decode_reference_resume = __ CreateLabel();
__ DecodeJNITransitionOrLocalJObject(mr_conv->ReturnRegister(),
decode_reference_slow_path.get(),
decode_reference_resume.get());
__ Bind(decode_reference_resume.get());
} else {
CallDecodeReferenceResult<kPointerSize>(
jni_asm.get(), main_jni_conv.get(), mr_conv->ReturnRegister(), main_out_arg_size);
}
} // if (!is_critical_native)
// 6. Pop local reference frame.
if (LIKELY(!is_critical_native)) {
PopLocalReferenceFrame<kPointerSize>(
jni_asm.get(), jni_env_reg, saved_cookie_reg, callee_save_temp);
}
// 7. Return from the JNI stub.
// 7.1. Move frame up now we're done with the out arg space.
// @CriticalNative remove out args together with the frame in RemoveFrame().
if (LIKELY(!is_critical_native)) {
__ DecreaseFrameSize(current_out_arg_size);
current_frame_size -= current_out_arg_size;
}
// 7.2 Unlock the synchronization object for synchronized methods.
// Do this before exception poll to avoid extra unlocking in the exception slow path.
if (UNLIKELY(is_synchronized)) {
ManagedRegister to_lock = main_jni_conv->LockingArgumentRegister();
mr_conv->ResetIterator(FrameOffset(current_frame_size));
if (is_static) {
// Pass the declaring class.
DCHECK(method_register.IsNoRegister()); // TODO: Preserve the method in `callee_save_temp`.
ManagedRegister temp = __ CoreRegisterWithSize(callee_save_temp, kRawPointerSize);
FrameOffset method_offset = mr_conv->MethodStackOffset();
__ Load(temp, method_offset, kRawPointerSize);
DCHECK_EQ(ArtMethod::DeclaringClassOffset().SizeValue(), 0u);
__ Load(to_lock, temp, MemberOffset(0u), kObjectReferenceSize);
} else {
// Pass the `this` argument from its spill slot.
__ Load(to_lock, mr_conv->CurrentParamStackOffset(), kObjectReferenceSize);
}
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pJniUnlockObject));
}
// 7.3. Process pending exceptions from JNI call or monitor exit.
// @CriticalNative methods do not need exception poll in the stub.
// Methods with reference return emit the exception poll earlier.
if (LIKELY(!is_critical_native) && !reference_return) {
__ ExceptionPoll(exception_slow_path.get());
}
// 7.4. For @FastNative, we never transitioned out of runnable, so there is no transition back.
// Perform a suspend check if there is a flag raised, unless we have done that above
// for reference return.
if (UNLIKELY(is_fast_native) && !reference_return) {
__ SuspendCheck(suspend_check_slow_path.get());
__ Bind(suspend_check_resume.get());
}
// 7.5. Check if method exit hooks needs to be called
// For critical native methods, we don't JIT stubs in debuggable runtimes.
// TODO(mythria): Add support to call method entry / exit hooks for critical native methods too.
std::unique_ptr<JNIMacroLabel> method_exit_hook_slow_path;
std::unique_ptr<JNIMacroLabel> method_exit_hook_return;
if (UNLIKELY(needs_entry_exit_hooks)) {
uint64_t address = reinterpret_cast64<uint64_t>(Runtime::Current()->GetInstrumentation());
int offset = instrumentation::Instrumentation::RunExitHooksOffset().Int32Value();
method_exit_hook_slow_path = __ CreateLabel();
method_exit_hook_return = __ CreateLabel();
__ TestByteAndJumpIfNotZero(address + offset, method_exit_hook_slow_path.get());
__ Bind(method_exit_hook_return.get());
}
// 7.6. Remove activation - need to restore callee save registers since the GC
// may have changed them.
DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(current_frame_size));
if (LIKELY(!is_critical_native) || !main_jni_conv->UseTailCall()) {
// We expect the compiled method to possibly be suspended during its
// execution, except in the case of a CriticalNative method.
bool may_suspend = !is_critical_native;
__ RemoveFrame(current_frame_size, callee_save_regs, may_suspend);
DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(current_frame_size));
}
// 8. Emit slow paths.
// 8.1. Read barrier slow path for the declaring class in the method for a static call.
// Skip this for @CriticalNative because we're not passing a `jclass` to the native method.
if (gUseReadBarrier && is_static && !is_critical_native) {
__ Bind(jclass_read_barrier_slow_path.get());
// Construct slow path for read barrier:
//
// For baker read barrier, do a fast check whether the class is already marked.
//
// Call into the runtime's `art_jni_read_barrier` and have it fix up
// the class address if it was moved.
//
// The entrypoint preserves the method register and argument registers.
if (kUseBakerReadBarrier) {
// We enter the slow path with the method register unclobbered and callee-save
// registers already spilled, so we can use callee-save scratch registers.
method_register = mr_conv->MethodRegister();
ManagedRegister temp = __ CoreRegisterWithSize(
main_jni_conv->CalleeSaveScratchRegisters()[0], kObjectReferenceSize);
// Load the declaring class reference.
DCHECK_EQ(ArtMethod::DeclaringClassOffset().SizeValue(), 0u);
__ Load(temp, method_register, MemberOffset(0u), kObjectReferenceSize);
// Return to main path if the class object is marked.
__ TestMarkBit(temp, jclass_read_barrier_return.get(), JNIMacroUnaryCondition::kNotZero);
}
ThreadOffset<kPointerSize> read_barrier = QUICK_ENTRYPOINT_OFFSET(kPointerSize,
pJniReadBarrier);
__ CallFromThread(read_barrier);
// Return to main path.
__ Jump(jclass_read_barrier_return.get());
}
// 8.2. Slow path for transition to Native.
if (LIKELY(!is_critical_native && !is_fast_native)) {
__ Bind(transition_to_native_slow_path.get());
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pJniMethodStart));
__ Jump(transition_to_native_resume.get());
}
// 8.3. Slow path for transition to Runnable.
if (LIKELY(!is_critical_native && !is_fast_native)) {
__ Bind(transition_to_runnable_slow_path.get());
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pJniMethodEnd));
__ Jump(transition_to_runnable_resume.get());
}
// 8.4. Exception poll slow path(s).
if (LIKELY(!is_critical_native)) {
__ Bind(exception_slow_path.get());
if (reference_return) {
// We performed the exception check early, so we need to adjust SP and pop IRT frame.
if (main_out_arg_size != 0) {
jni_asm->cfi().AdjustCFAOffset(main_out_arg_size);
__ DecreaseFrameSize(main_out_arg_size);
}
PopLocalReferenceFrame<kPointerSize>(
jni_asm.get(), jni_env_reg, saved_cookie_reg, callee_save_temp);
}
DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(current_frame_size));
__ DeliverPendingException();
}
// 8.5 Slow path for decoding the `jobject`.
if (reference_return && inline_decode_reference) {
__ Bind(decode_reference_slow_path.get());
if (main_out_arg_size != 0) {
jni_asm->cfi().AdjustCFAOffset(main_out_arg_size);
}
CallDecodeReferenceResult<kPointerSize>(
jni_asm.get(), main_jni_conv.get(), mr_conv->ReturnRegister(), main_out_arg_size);
__ Jump(decode_reference_resume.get());
if (main_out_arg_size != 0) {
jni_asm->cfi().AdjustCFAOffset(-main_out_arg_size);
}
}
// 8.6. Suspend check slow path.
if (UNLIKELY(is_fast_native)) {
__ Bind(suspend_check_slow_path.get());
if (reference_return && main_out_arg_size != 0) {
jni_asm->cfi().AdjustCFAOffset(main_out_arg_size);
__ DecreaseFrameSize(main_out_arg_size);
}
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pTestSuspend));
if (reference_return) {
// Suspend check entry point overwrites top of managed stack and leaves it clobbered.
// We need to restore the top for subsequent runtime call to `JniDecodeReferenceResult()`.
__ StoreStackPointerToThread(Thread::TopOfManagedStackOffset<kPointerSize>(), should_tag_sp);
}
if (reference_return && main_out_arg_size != 0) {
__ IncreaseFrameSize(main_out_arg_size);
}
__ Jump(suspend_check_resume.get());
if (reference_return && main_out_arg_size != 0) {
jni_asm->cfi().AdjustCFAOffset(-main_out_arg_size);
}
}
// 8.7. Method entry / exit hooks slow paths.
if (UNLIKELY(needs_entry_exit_hooks)) {
__ Bind(method_entry_hook_slow_path.get());
// Use Jni specific method entry hook that saves all the arguments. We have only saved the
// callee save registers at this point. So go through Jni specific stub that saves the rest
// of the live registers.
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pJniMethodEntryHook));
__ ExceptionPoll(exception_slow_path.get());
__ Jump(method_entry_hook_return.get());
__ Bind(method_exit_hook_slow_path.get());
// Method exit hooks is called just before tearing down the frame. So there are no live
// registers and we can directly call the method exit hook and don't need a Jni specific
// entrypoint.
__ Move(mr_conv->ArgumentRegisterForMethodExitHook(), managed_frame_size);
__ CallFromThread(QUICK_ENTRYPOINT_OFFSET(kPointerSize, pMethodExitHook));
__ Jump(method_exit_hook_return.get());
}
// 9. Finalize code generation.
__ FinalizeCode();
size_t cs = __ CodeSize();
std::vector<uint8_t> managed_code(cs);
MemoryRegion code(&managed_code[0], managed_code.size());
__ FinalizeInstructions(code);
return JniCompiledMethod(instruction_set,
std::move(managed_code),
managed_frame_size,
main_jni_conv->CoreSpillMask(),
main_jni_conv->FpSpillMask(),
ArrayRef<const uint8_t>(*jni_asm->cfi().data()));
}
template <PointerSize kPointerSize>
static void PushLocalReferenceFrame(JNIMacroAssembler<kPointerSize>* jni_asm,
ManagedRegister jni_env_reg,
ManagedRegister saved_cookie_reg,
ManagedRegister temp_reg) {
const size_t kRawPointerSize = static_cast<size_t>(kPointerSize);
const MemberOffset jni_env_cookie_offset = JNIEnvExt::LocalRefCookieOffset(kRawPointerSize);
const MemberOffset jni_env_segment_state_offset = JNIEnvExt::SegmentStateOffset(kRawPointerSize);
// Load the old cookie that we shall need to restore.
__ Load(saved_cookie_reg, jni_env_reg, jni_env_cookie_offset, kIRTCookieSize);
// Set the cookie in JNI environment to the current segment state.
__ Load(temp_reg, jni_env_reg, jni_env_segment_state_offset, kIRTCookieSize);
__ Store(jni_env_reg, jni_env_cookie_offset, temp_reg, kIRTCookieSize);
}
template <PointerSize kPointerSize>
static void PopLocalReferenceFrame(JNIMacroAssembler<kPointerSize>* jni_asm,
ManagedRegister jni_env_reg,
ManagedRegister saved_cookie_reg,
ManagedRegister temp_reg) {
const size_t kRawPointerSize = static_cast<size_t>(kPointerSize);
const MemberOffset jni_env_cookie_offset = JNIEnvExt::LocalRefCookieOffset(kRawPointerSize);
const MemberOffset jni_env_segment_state_offset = JNIEnvExt::SegmentStateOffset(kRawPointerSize);
// Set the current segment state to the current cookie in JNI environment.
__ Load(temp_reg, jni_env_reg, jni_env_cookie_offset, kIRTCookieSize);
__ Store(jni_env_reg, jni_env_segment_state_offset, temp_reg, kIRTCookieSize);
// Restore the cookie in JNI environment to the saved value.
__ Store(jni_env_reg, jni_env_cookie_offset, saved_cookie_reg, kIRTCookieSize);
}
template <PointerSize kPointerSize>
static void SetNativeParameter(JNIMacroAssembler<kPointerSize>* jni_asm,
JniCallingConvention* jni_conv,
ManagedRegister in_reg) {
if (jni_conv->IsCurrentParamOnStack()) {
FrameOffset dest = jni_conv->CurrentParamStackOffset();
__ StoreRawPtr(dest, in_reg);
} else {
if (!jni_conv->CurrentParamRegister().Equals(in_reg)) {
__ Move(jni_conv->CurrentParamRegister(), in_reg, jni_conv->CurrentParamSize());
}
}
}
template <PointerSize kPointerSize>
static void CallDecodeReferenceResult(JNIMacroAssembler<kPointerSize>* jni_asm,
JniCallingConvention* jni_conv,
ManagedRegister mr_return_reg,
size_t main_out_arg_size) {
// We abuse the JNI calling convention here, that is guaranteed to support passing
// two pointer arguments, `JNIEnv*` and `jclass`/`jobject`.
jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
ThreadOffset<kPointerSize> jni_decode_reference_result =
QUICK_ENTRYPOINT_OFFSET(kPointerSize, pJniDecodeReferenceResult);
// Pass result.
SetNativeParameter(jni_asm, jni_conv, mr_return_reg);
jni_conv->Next();
if (jni_conv->IsCurrentParamInRegister()) {
__ GetCurrentThread(jni_conv->CurrentParamRegister());
__ Call(jni_conv->CurrentParamRegister(), Offset(jni_decode_reference_result));
} else {
__ GetCurrentThread(jni_conv->CurrentParamStackOffset());
__ CallFromThread(jni_decode_reference_result);
}
// Note: If the native ABI returns the pointer in a register different from
// `mr_return_register`, the `JniDecodeReferenceResult` entrypoint must be
// a stub that moves the result to `mr_return_register`.
}
JniCompiledMethod ArtQuickJniCompileMethod(const CompilerOptions& compiler_options,
uint32_t access_flags,
uint32_t method_idx,
const DexFile& dex_file,
ArenaAllocator* allocator) {
if (Is64BitInstructionSet(compiler_options.GetInstructionSet())) {
return ArtJniCompileMethodInternal<PointerSize::k64>(
compiler_options, access_flags, method_idx, dex_file, allocator);
} else {
return ArtJniCompileMethodInternal<PointerSize::k32>(
compiler_options, access_flags, method_idx, dex_file, allocator);
}
}
} // namespace art