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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 "assembler.h"
#include <algorithm>
#include <vector>
#include "base/casts.h"
#include "base/globals.h"
#include "base/memory_region.h"
namespace art {
AssemblerBuffer::AssemblerBuffer(ArenaAllocator* allocator)
: allocator_(allocator) {
static const size_t kInitialBufferCapacity = 4 * KB;
contents_ = allocator_->AllocArray<uint8_t>(kInitialBufferCapacity, kArenaAllocAssembler);
cursor_ = contents_;
limit_ = ComputeLimit(contents_, kInitialBufferCapacity);
fixup_ = nullptr;
slow_path_ = nullptr;
#ifndef NDEBUG
has_ensured_capacity_ = false;
fixups_processed_ = false;
#endif
// Verify internal state.
CHECK_EQ(Capacity(), kInitialBufferCapacity);
CHECK_EQ(Size(), 0U);
}
AssemblerBuffer::~AssemblerBuffer() {
if (allocator_->IsRunningOnMemoryTool()) {
allocator_->MakeInaccessible(contents_, Capacity());
}
}
void AssemblerBuffer::ProcessFixups(const MemoryRegion& region) {
AssemblerFixup* fixup = fixup_;
while (fixup != nullptr) {
fixup->Process(region, fixup->position());
fixup = fixup->previous();
}
}
void AssemblerBuffer::FinalizeInstructions(const MemoryRegion& instructions) {
// Copy the instructions from the buffer.
MemoryRegion from(reinterpret_cast<void*>(contents()), Size());
instructions.CopyFrom(0, from);
// Process fixups in the instructions.
ProcessFixups(instructions);
#ifndef NDEBUG
fixups_processed_ = true;
#endif
}
void AssemblerBuffer::ExtendCapacity(size_t min_capacity) {
size_t old_size = Size();
size_t old_capacity = Capacity();
DCHECK_GT(min_capacity, old_capacity);
size_t new_capacity = std::min(old_capacity * 2, old_capacity + 1 * MB);
new_capacity = std::max(new_capacity, min_capacity);
// Allocate the new data area and copy contents of the old one to it.
contents_ = reinterpret_cast<uint8_t*>(
allocator_->Realloc(contents_, old_capacity, new_capacity, kArenaAllocAssembler));
// Update the cursor and recompute the limit.
cursor_ = contents_ + old_size;
limit_ = ComputeLimit(contents_, new_capacity);
// Verify internal state.
CHECK_EQ(Capacity(), new_capacity);
CHECK_EQ(Size(), old_size);
}
void DebugFrameOpCodeWriterForAssembler::ImplicitlyAdvancePC() {
uint32_t pc = dchecked_integral_cast<uint32_t>(assembler_->CodeSize());
if (delay_emitting_advance_pc_) {
uint32_t stream_pos = dchecked_integral_cast<uint32_t>(opcodes_.size());
delayed_advance_pcs_.push_back(DelayedAdvancePC {stream_pos, pc});
} else {
AdvancePC(pc);
}
}
} // namespace art