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/*
* Copyright (C) 2012 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 "class_linker.h"
#include "compilation_unit.h"
#include "compiled_method.h"
#include "compiler.h"
#include "compiler_llvm.h"
#include "ir_builder.h"
#include "logging.h"
#include "oat_compilation_unit.h"
#include "object.h"
#include "runtime.h"
#include "runtime_support_func.h"
#include "utils_llvm.h"
#include <llvm/BasicBlock.h>
#include <llvm/DerivedTypes.h>
#include <llvm/Function.h>
#include <llvm/ADT/SmallVector.h>
#include <llvm/Type.h>
namespace art {
namespace compiler_llvm {
using namespace runtime_support;
JniCompiler::JniCompiler(CompilationUnit* cunit,
Compiler const& compiler,
OatCompilationUnit* oat_compilation_unit)
: cunit_(cunit), compiler_(&compiler), module_(cunit_->GetModule()),
context_(cunit_->GetLLVMContext()), irb_(*cunit_->GetIRBuilder()),
oat_compilation_unit_(oat_compilation_unit),
access_flags_(oat_compilation_unit->access_flags_),
method_idx_(oat_compilation_unit->method_idx_),
dex_file_(oat_compilation_unit->dex_file_) {
// Check: Ensure that JNI compiler will only get "native" method
CHECK((access_flags_ & kAccNative) != 0);
}
CompiledMethod* JniCompiler::Compile() {
const bool is_static = (access_flags_ & kAccStatic) != 0;
const bool is_synchronized = (access_flags_ & kAccSynchronized) != 0;
DexFile::MethodId const& method_id = dex_file_->GetMethodId(method_idx_);
char const return_shorty = dex_file_->GetMethodShorty(method_id)[0];
llvm::Value* this_object_or_class_object;
CreateFunction();
// Set argument name
llvm::Function::arg_iterator arg_begin(func_->arg_begin());
llvm::Function::arg_iterator arg_end(func_->arg_end());
llvm::Function::arg_iterator arg_iter(arg_begin);
DCHECK_NE(arg_iter, arg_end);
arg_iter->setName("method");
llvm::Value* method_object_addr = arg_iter++;
if (!is_static) {
// Non-static, the second argument is "this object"
this_object_or_class_object = arg_iter++;
} else {
// Load class object
this_object_or_class_object =
irb_.LoadFromObjectOffset(method_object_addr,
AbstractMethod::DeclaringClassOffset().Int32Value(),
irb_.getJObjectTy(),
kTBAAConstJObject);
}
// Actual argument (ignore method and this object)
arg_begin = arg_iter;
// Count the number of Object* arguments
uint32_t sirt_size = 1;
// "this" object pointer for non-static
// "class" object pointer for static
for (unsigned i = 0; arg_iter != arg_end; ++i, ++arg_iter) {
#if !defined(NDEBUG)
arg_iter->setName(StringPrintf("a%u", i));
#endif
if (arg_iter->getType() == irb_.getJObjectTy()) {
++sirt_size;
}
}
// Shadow stack
llvm::StructType* shadow_frame_type = irb_.getShadowFrameTy(sirt_size);
llvm::AllocaInst* shadow_frame_ = irb_.CreateAlloca(shadow_frame_type);
// Store the dex pc
irb_.StoreToObjectOffset(shadow_frame_,
ShadowFrame::DexPCOffset(),
irb_.getInt32(DexFile::kDexNoIndex),
kTBAAShadowFrame);
// Push the shadow frame
llvm::Value* shadow_frame_upcast = irb_.CreateConstGEP2_32(shadow_frame_, 0, 0);
llvm::Value* old_shadow_frame =
irb_.Runtime().EmitPushShadowFrame(shadow_frame_upcast, method_object_addr, sirt_size);
// Get JNIEnv
llvm::Value* jni_env_object_addr =
irb_.Runtime().EmitLoadFromThreadOffset(Thread::JniEnvOffset().Int32Value(),
irb_.getJObjectTy(),
kTBAAJRuntime);
// Get callee code_addr
llvm::Value* code_addr =
irb_.LoadFromObjectOffset(method_object_addr,
AbstractMethod::NativeMethodOffset().Int32Value(),
GetFunctionType(method_idx_, is_static, true)->getPointerTo(),
kTBAAJRuntime);
// Load actual parameters
std::vector<llvm::Value*> args;
// The 1st parameter: JNIEnv*
args.push_back(jni_env_object_addr);
// Variables for GetElementPtr
llvm::Value* gep_index[] = {
irb_.getInt32(0), // No displacement for shadow frame pointer
irb_.getInt32(1), // SIRT
NULL,
};
size_t sirt_member_index = 0;
// Store the "this object or class object" to SIRT
gep_index[2] = irb_.getInt32(sirt_member_index++);
llvm::Value* sirt_field_addr = irb_.CreateGEP(shadow_frame_, gep_index);
irb_.CreateStore(this_object_or_class_object, sirt_field_addr, kTBAAShadowFrame);
// Push the "this object or class object" to out args
this_object_or_class_object = irb_.CreateBitCast(sirt_field_addr, irb_.getJObjectTy());
args.push_back(this_object_or_class_object);
// Store arguments to SIRT, and push back to args
for (arg_iter = arg_begin; arg_iter != arg_end; ++arg_iter) {
if (arg_iter->getType() == irb_.getJObjectTy()) {
// Store the reference type arguments to SIRT
gep_index[2] = irb_.getInt32(sirt_member_index++);
llvm::Value* sirt_field_addr = irb_.CreateGEP(shadow_frame_, gep_index);
irb_.CreateStore(arg_iter, sirt_field_addr, kTBAAShadowFrame);
// Note null is placed in the SIRT but the jobject passed to the native code must be null
// (not a pointer into the SIRT as with regular references).
llvm::Value* equal_null = irb_.CreateICmpEQ(arg_iter, irb_.getJNull());
llvm::Value* arg =
irb_.CreateSelect(equal_null,
irb_.getJNull(),
irb_.CreateBitCast(sirt_field_addr, irb_.getJObjectTy()));
args.push_back(arg);
} else {
args.push_back(arg_iter);
}
}
llvm::Value* saved_local_ref_cookie;
{ // JniMethodStart
RuntimeId func_id = is_synchronized ? JniMethodStartSynchronized
: JniMethodStart;
llvm::SmallVector<llvm::Value*, 2> args;
if (is_synchronized) {
args.push_back(this_object_or_class_object);
}
args.push_back(irb_.Runtime().EmitGetCurrentThread());
saved_local_ref_cookie =
irb_.CreateCall(irb_.GetRuntime(func_id), args);
}
// Call!!!
llvm::Value* retval = irb_.CreateCall(code_addr, args);
{ // JniMethodEnd
bool is_return_ref = return_shorty == 'L';
RuntimeId func_id =
is_return_ref ? (is_synchronized ? JniMethodEndWithReferenceSynchronized
: JniMethodEndWithReference)
: (is_synchronized ? JniMethodEndSynchronized
: JniMethodEnd);
llvm::SmallVector<llvm::Value*, 4> args;
if (is_return_ref) {
args.push_back(retval);
}
args.push_back(saved_local_ref_cookie);
if (is_synchronized) {
args.push_back(this_object_or_class_object);
}
args.push_back(irb_.Runtime().EmitGetCurrentThread());
llvm::Value* decoded_jobject =
irb_.CreateCall(irb_.GetRuntime(func_id), args);
// Return decoded jobject if return reference.
if (is_return_ref) {
retval = decoded_jobject;
}
}
// Pop the shadow frame
irb_.Runtime().EmitPopShadowFrame(old_shadow_frame);
// Return!
if (return_shorty != 'V') {
irb_.CreateRet(retval);
} else {
irb_.CreateRetVoid();
}
// Verify the generated bitcode
VERIFY_LLVM_FUNCTION(*func_);
cunit_->Materialize();
return new CompiledMethod(cunit_->GetInstructionSet(),
cunit_->GetCompiledCode());
}
void JniCompiler::CreateFunction() {
// LLVM function name
std::string func_name(ElfFuncName(cunit_->GetIndex()));
const bool is_static = (access_flags_ & kAccStatic) != 0;
// Get function type
llvm::FunctionType* func_type =
GetFunctionType(method_idx_, is_static, false);
// Create function
func_ = llvm::Function::Create(func_type, llvm::Function::ExternalLinkage,
func_name, module_);
// Create basic block
llvm::BasicBlock* basic_block = llvm::BasicBlock::Create(*context_, "B0", func_);
// Set insert point
irb_.SetInsertPoint(basic_block);
}
llvm::FunctionType* JniCompiler::GetFunctionType(uint32_t method_idx,
bool is_static, bool is_native_function) {
// Get method signature
DexFile::MethodId const& method_id = dex_file_->GetMethodId(method_idx);
uint32_t shorty_size;
const char* shorty = dex_file_->GetMethodShorty(method_id, &shorty_size);
CHECK_GE(shorty_size, 1u);
// Get return type
llvm::Type* ret_type = irb_.getJType(shorty[0], kAccurate);
// Get argument type
std::vector<llvm::Type*> args_type;
args_type.push_back(irb_.getJObjectTy()); // method object pointer
if (!is_static || is_native_function) {
// "this" object pointer for non-static
// "class" object pointer for static naitve
args_type.push_back(irb_.getJType('L', kAccurate));
}
for (uint32_t i = 1; i < shorty_size; ++i) {
args_type.push_back(irb_.getJType(shorty[i], kAccurate));
}
return llvm::FunctionType::get(ret_type, args_type, false);
}
} // namespace compiler_llvm
} // namespace art