Move startop/tools/view_compiler to startop/view_compiler

This is planned to ship on device, so by convention the view_compiler should not
be in a tools directory.

Change-Id: I0eb03812d77ec38edc3908725acb40bacb345ecd

1 files changed, 214 insertions, 0 deletions

diff --git a/startop/view_compiler/dex_builder.cc b/startop/view_compiler/dex_builder.cc
new file mode 100644
index 000000000000..7a9f41fd8f38
--- /dev/null
+++ b/startop/view_compiler/dex_builder.cc
@@ -0,0 +1,214 @@
+/*
+ * Copyright (C) 2018 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 "dex_builder.h"
+
+#include "dex/descriptors_names.h"
+#include "dex/dex_instruction.h"
+
+#include <fstream>
+#include <memory>
+
+namespace startop {
+namespace dex {
+
+using std::shared_ptr;
+using std::string;
+
+using art::Instruction;
+using ::dex::kAccPublic;
+
+const TypeDescriptor TypeDescriptor::Int() { return TypeDescriptor{"I"}; };
+const TypeDescriptor TypeDescriptor::Void() { return TypeDescriptor{"V"}; };
+
+namespace {
+// From https://source.android.com/devices/tech/dalvik/dex-format#dex-file-magic
+constexpr uint8_t kDexFileMagic[]{0x64, 0x65, 0x78, 0x0a, 0x30, 0x33, 0x38, 0x00};
+
+// Strings lengths can be 32 bits long, but encoded as LEB128 this can take up to five bytes.
+constexpr size_t kMaxEncodedStringLength{5};
+
+}  // namespace
+
+void* TrackingAllocator::Allocate(size_t size) {
+  std::unique_ptr<uint8_t[]> buffer = std::make_unique<uint8_t[]>(size);
+  void* raw_buffer = buffer.get();
+  allocations_[raw_buffer] = std::move(buffer);
+  return raw_buffer;
+}
+
+void TrackingAllocator::Free(void* ptr) { allocations_.erase(allocations_.find(ptr)); }
+
+// Write out a DEX file that is basically:
+//
+// package dextest;
+// public class DexTest {
+//     public static int foo() { return 5; }
+// }
+void WriteTestDexFile(const string& filename) {
+  DexBuilder dex_file;
+
+  ClassBuilder cbuilder{dex_file.MakeClass("dextest.DexTest")};
+  cbuilder.set_source_file("dextest.java");
+
+  MethodBuilder method{cbuilder.CreateMethod("foo", Prototype{TypeDescriptor::Int()})};
+
+  MethodBuilder::Register r = method.MakeRegister();
+  method.BuildConst4(r, 5);
+  method.BuildReturn(r);
+
+  method.Encode();
+
+  slicer::MemView image{dex_file.CreateImage()};
+
+  std::ofstream out_file(filename);
+  out_file.write(image.ptr<const char>(), image.size());
+}
+
+DexBuilder::DexBuilder() : dex_file_{std::make_shared<ir::DexFile>()} {
+  dex_file_->magic = slicer::MemView{kDexFileMagic, sizeof(kDexFileMagic)};
+}
+
+slicer::MemView DexBuilder::CreateImage() {
+  ::dex::Writer writer(dex_file_);
+  size_t image_size{0};
+  ::dex::u1* image = writer.CreateImage(&allocator_, &image_size);
+  return slicer::MemView{image, image_size};
+}
+
+ir::String* DexBuilder::GetOrAddString(const std::string& string) {
+  ir::String*& entry = strings_[string];
+
+  if (entry == nullptr) {
+    // Need to encode the length and then write out the bytes, including 1 byte for null terminator
+    auto buffer = std::make_unique<uint8_t[]>(string.size() + kMaxEncodedStringLength + 1);
+    uint8_t* string_data_start = ::dex::WriteULeb128(buffer.get(), string.size());
+
+    size_t header_length =
+        reinterpret_cast<uintptr_t>(string_data_start) - reinterpret_cast<uintptr_t>(buffer.get());
+
+    auto end = std::copy(string.begin(), string.end(), string_data_start);
+    *end = '\0';
+
+    entry = Alloc<ir::String>();
+    // +1 for null terminator
+    entry->data = slicer::MemView{buffer.get(), header_length + string.size() + 1};
+    string_data_.push_back(std::move(buffer));
+  }
+  return entry;
+}
+
+ClassBuilder DexBuilder::MakeClass(const std::string& name) {
+  auto* class_def = Alloc<ir::Class>();
+  ir::Type* type_def = GetOrAddType(art::DotToDescriptor(name.c_str()));
+  type_def->class_def = class_def;
+
+  class_def->type = type_def;
+  class_def->super_class = GetOrAddType(art::DotToDescriptor("java.lang.Object"));
+  class_def->access_flags = kAccPublic;
+  return ClassBuilder{this, class_def};
+}
+
+// TODO(eholk): we probably want GetOrAddString() also
+ir::Type* DexBuilder::GetOrAddType(const std::string& descriptor) {
+  if (types_by_descriptor_.find(descriptor) != types_by_descriptor_.end()) {
+    return types_by_descriptor_[descriptor];
+  }
+
+  ir::Type* type = Alloc<ir::Type>();
+  type->descriptor = GetOrAddString(descriptor);
+  types_by_descriptor_[descriptor] = type;
+  return type;
+}
+
+ir::Proto* Prototype::Encode(DexBuilder* dex) const {
+  auto* proto = dex->Alloc<ir::Proto>();
+  proto->shorty = dex->GetOrAddString(Shorty());
+  proto->return_type = dex->GetOrAddType(return_type_.descriptor());
+  if (param_types_.size() > 0) {
+    proto->param_types = dex->Alloc<ir::TypeList>();
+    for (const auto& param_type : param_types_) {
+      proto->param_types->types.push_back(dex->GetOrAddType(param_type.descriptor()));
+    }
+  } else {
+    proto->param_types = nullptr;
+  }
+  return proto;
+}
+
+std::string Prototype::Shorty() const {
+  std::string shorty;
+  shorty.append(return_type_.short_descriptor());
+  for (const auto& type_descriptor : param_types_) {
+    shorty.append(type_descriptor.short_descriptor());
+  }
+  return shorty;
+}
+
+ClassBuilder::ClassBuilder(DexBuilder* parent, ir::Class* class_def)
+    : parent_(parent), class_(class_def) {}
+
+MethodBuilder ClassBuilder::CreateMethod(const std::string& name, Prototype prototype) {
+  ir::String* dex_name{parent_->GetOrAddString(name)};
+
+  auto* decl = parent_->Alloc<ir::MethodDecl>();
+  decl->name = dex_name;
+  decl->parent = class_->type;
+  decl->prototype = prototype.Encode(parent_);
+
+  return MethodBuilder{parent_, class_, decl};
+}
+
+void ClassBuilder::set_source_file(const string& source) {
+  class_->source_file = parent_->GetOrAddString(source);
+}
+
+MethodBuilder::MethodBuilder(DexBuilder* dex, ir::Class* class_def, ir::MethodDecl* decl)
+    : dex_{dex}, class_{class_def}, decl_{decl} {}
+
+ir::EncodedMethod* MethodBuilder::Encode() {
+  auto* method = dex_->Alloc<ir::EncodedMethod>();
+  method->decl = decl_;
+
+  // TODO: make access flags configurable
+  method->access_flags = kAccPublic | ::dex::kAccStatic;
+
+  auto* code = dex_->Alloc<ir::Code>();
+  code->registers = num_registers_;
+  // TODO: support ins and outs
+  code->instructions = slicer::ArrayView<const ::dex::u2>(buffer_.data(), buffer_.size());
+  method->code = code;
+
+  class_->direct_methods.push_back(method);
+
+  return method;
+}
+
+MethodBuilder::Register MethodBuilder::MakeRegister() { return num_registers_++; }
+
+void MethodBuilder::BuildReturn() { buffer_.push_back(Instruction::RETURN_VOID); }
+
+void MethodBuilder::BuildReturn(Register src) { buffer_.push_back(Instruction::RETURN | src << 8); }
+
+void MethodBuilder::BuildConst4(Register target, int value) {
+  DCHECK_LT(value, 16);
+  // TODO: support more registers
+  DCHECK_LT(target, 16);
+  buffer_.push_back(Instruction::CONST_4 | (value << 12) | (target << 8));
+}
+
+}  // namespace dex
+}  // namespace startop