// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "test/cctest/interpreter/bytecode-expectations-printer.h"

#include <iomanip>
#include <iostream>
#include <vector>

#include "include/libplatform/libplatform.h"
#include "include/v8.h"

#include "src/base/logging.h"
#include "src/compiler.h"
#include "src/runtime/runtime.h"

#include "src/interpreter/bytecode-array-iterator.h"
#include "src/interpreter/bytecode-generator.h"
#include "src/interpreter/bytecodes.h"
#include "src/interpreter/interpreter-intrinsics.h"
#include "src/interpreter/interpreter.h"
#include "src/source-position-table.h"

namespace v8 {
namespace internal {
namespace interpreter {

// static
const char* const BytecodeExpectationsPrinter::kDefaultTopFunctionName =
    "__genbckexp_wrapper__";
const char* const BytecodeExpectationsPrinter::kIndent = "  ";

v8::Local<v8::String> BytecodeExpectationsPrinter::V8StringFromUTF8(
    const char* data) const {
  return v8::String::NewFromUtf8(isolate_, data, v8::NewStringType::kNormal)
      .ToLocalChecked();
}

std::string BytecodeExpectationsPrinter::WrapCodeInFunction(
    const char* function_name, const std::string& function_body) const {
  std::ostringstream program_stream;
  program_stream << "function " << function_name << "() {" << function_body
                 << "}\n"
                 << function_name << "();";

  return program_stream.str();
}

v8::Local<v8::Script> BytecodeExpectationsPrinter::Compile(
    const char* program) const {
  v8::Local<v8::String> source = V8StringFromUTF8(program);
  return v8::Script::Compile(isolate_->GetCurrentContext(), source)
      .ToLocalChecked();
}

void BytecodeExpectationsPrinter::Run(v8::Local<v8::Script> script) const {
  (void)script->Run(isolate_->GetCurrentContext());
}

i::Handle<v8::internal::BytecodeArray>
BytecodeExpectationsPrinter::GetBytecodeArrayForGlobal(
    const char* global_name) const {
  const v8::Local<v8::Context>& context = isolate_->GetCurrentContext();
  v8::Local<v8::String> v8_global_name = V8StringFromUTF8(global_name);
  v8::Local<v8::Function> function = v8::Local<v8::Function>::Cast(
      context->Global()->Get(context, v8_global_name).ToLocalChecked());
  i::Handle<i::JSFunction> js_function =
      i::Handle<i::JSFunction>::cast(v8::Utils::OpenHandle(*function));

  i::Handle<i::BytecodeArray> bytecodes =
      i::handle(js_function->shared()->bytecode_array(), i_isolate());

  return bytecodes;
}

i::Handle<i::BytecodeArray>
BytecodeExpectationsPrinter::GetBytecodeArrayForScript(
    v8::Local<v8::Script> script) const {
  i::Handle<i::JSFunction> js_function = v8::Utils::OpenHandle(*script);
  return i::handle(js_function->shared()->bytecode_array(), i_isolate());
}

void BytecodeExpectationsPrinter::PrintEscapedString(
    std::ostream& stream, const std::string& string) const {
  for (char c : string) {
    switch (c) {
      case '"':
        stream << "\\\"";
        break;
      case '\\':
        stream << "\\\\";
        break;
      default:
        stream << c;
        break;
    }
  }
}

void BytecodeExpectationsPrinter::PrintBytecodeOperand(
    std::ostream& stream, const BytecodeArrayIterator& bytecode_iterator,
    const Bytecode& bytecode, int op_index, int parameter_count) const {
  OperandType op_type = Bytecodes::GetOperandType(bytecode, op_index);
  OperandSize op_size = Bytecodes::GetOperandSize(
      bytecode, op_index, bytecode_iterator.current_operand_scale());

  const char* size_tag;
  switch (op_size) {
    case OperandSize::kByte:
      size_tag = "8";
      break;
    case OperandSize::kShort:
      size_tag = "16";
      break;
    case OperandSize::kQuad:
      size_tag = "32";
      break;
    default:
      UNREACHABLE();
      return;
  }

  if (Bytecodes::IsRegisterOperandType(op_type)) {
    Register register_value = bytecode_iterator.GetRegisterOperand(op_index);
    stream << 'R';
    if (op_size != OperandSize::kByte) stream << size_tag;
    if (register_value.is_new_target()) {
      stream << "(new_target)";
    } else if (register_value.is_current_context()) {
      stream << "(context)";
    } else if (register_value.is_function_closure()) {
      stream << "(closure)";
    } else if (register_value.is_parameter()) {
      int parameter_index = register_value.ToParameterIndex(parameter_count);
      if (parameter_index == 0) {
        stream << "(this)";
      } else {
        stream << "(arg" << (parameter_index - 1) << ')';
      }
    } else {
      stream << '(' << register_value.index() << ')';
    }
  } else {
    stream << 'U' << size_tag << '(';

    switch (op_type) {
      case OperandType::kFlag8:
        stream << bytecode_iterator.GetFlagOperand(op_index);
        break;
      case OperandType::kIdx:
        stream << bytecode_iterator.GetIndexOperand(op_index);
        break;
      case OperandType::kImm:
        stream << bytecode_iterator.GetImmediateOperand(op_index);
        break;
      case OperandType::kRegCount:
        stream << bytecode_iterator.GetRegisterCountOperand(op_index);
        break;
      case OperandType::kRuntimeId: {
        Runtime::FunctionId id =
            bytecode_iterator.GetRuntimeIdOperand(op_index);
        stream << "Runtime::k" << i::Runtime::FunctionForId(id)->name;
        break;
      }
      case OperandType::kIntrinsicId: {
        Runtime::FunctionId id =
            bytecode_iterator.GetIntrinsicIdOperand(op_index);
        stream << "Runtime::k" << i::Runtime::FunctionForId(id)->name;
        break;
      }
      default:
        UNREACHABLE();
    }

    stream << ')';
  }
}

void BytecodeExpectationsPrinter::PrintBytecode(
    std::ostream& stream, const BytecodeArrayIterator& bytecode_iterator,
    int parameter_count) const {
  Bytecode bytecode = bytecode_iterator.current_bytecode();
  OperandScale operand_scale = bytecode_iterator.current_operand_scale();
  if (Bytecodes::OperandScaleRequiresPrefixBytecode(operand_scale)) {
    Bytecode prefix = Bytecodes::OperandScaleToPrefixBytecode(operand_scale);
    stream << "B(" << Bytecodes::ToString(prefix) << "), ";
  }
  stream << "B(" << Bytecodes::ToString(bytecode) << ')';
  int operands_count = Bytecodes::NumberOfOperands(bytecode);
  for (int op_index = 0; op_index < operands_count; ++op_index) {
    stream << ", ";
    PrintBytecodeOperand(stream, bytecode_iterator, bytecode, op_index,
                         parameter_count);
  }
}

void BytecodeExpectationsPrinter::PrintSourcePosition(
    std::ostream& stream, SourcePositionTableIterator& source_iterator,
    int bytecode_offset) const {
  static const size_t kPositionWidth = 4;
  if (!source_iterator.done() &&
      source_iterator.code_offset() == bytecode_offset) {
    stream << "/* " << std::setw(kPositionWidth)
           << source_iterator.source_position();
    if (source_iterator.is_statement()) {
      stream << " S> */ ";
    } else {
      stream << " E> */ ";
    }
    source_iterator.Advance();
  } else {
    stream << "   " << std::setw(kPositionWidth) << ' ' << "       ";
  }
}

void BytecodeExpectationsPrinter::PrintV8String(std::ostream& stream,
                                                i::String* string) const {
  stream << '"';
  for (int i = 0, length = string->length(); i < length; ++i) {
    stream << i::AsEscapedUC16ForJSON(string->Get(i));
  }
  stream << '"';
}

void BytecodeExpectationsPrinter::PrintConstant(
    std::ostream& stream, i::Handle<i::Object> constant) const {
  switch (const_pool_type_) {
    case ConstantPoolType::kString:
      CHECK(constant->IsString());
      PrintV8String(stream, i::String::cast(*constant));
      break;
    case ConstantPoolType::kNumber:
      if (constant->IsSmi()) {
        i::Smi::cast(*constant)->SmiPrint(stream);
      } else if (constant->IsHeapNumber()) {
        i::HeapNumber::cast(*constant)->HeapNumberPrint(stream);
      } else {
        UNREACHABLE();
      }
      break;
    case ConstantPoolType::kMixed:
      if (constant->IsSmi()) {
        stream << "kInstanceTypeDontCare";
      } else {
        stream << "InstanceType::"
               << i::HeapObject::cast(*constant)->map()->instance_type();
      }
      break;
    case ConstantPoolType::kUnknown:
    default:
      UNREACHABLE();
      return;
  }
}

void BytecodeExpectationsPrinter::PrintFrameSize(
    std::ostream& stream, i::Handle<i::BytecodeArray> bytecode_array) const {
  const int kPointerSize = sizeof(void*);
  int frame_size = bytecode_array->frame_size();

  DCHECK_EQ(frame_size % kPointerSize, 0);
  stream << "frame size: " << frame_size / kPointerSize
         << "\nparameter count: " << bytecode_array->parameter_count() << '\n';
}

void BytecodeExpectationsPrinter::PrintBytecodeSequence(
    std::ostream& stream, i::Handle<i::BytecodeArray> bytecode_array) const {
  stream << "bytecode array length: " << bytecode_array->length()
         << "\nbytecodes: [\n";

  SourcePositionTableIterator source_iterator(
      bytecode_array->source_position_table());
  BytecodeArrayIterator bytecode_iterator(bytecode_array);
  for (; !bytecode_iterator.done(); bytecode_iterator.Advance()) {
    stream << kIndent;
    PrintSourcePosition(stream, source_iterator,
                        bytecode_iterator.current_offset());
    PrintBytecode(stream, bytecode_iterator, bytecode_array->parameter_count());
    stream << ",\n";
  }
  stream << "]\n";
}

void BytecodeExpectationsPrinter::PrintConstantPool(
    std::ostream& stream, i::FixedArray* constant_pool) const {
  stream << "constant pool: [\n";
  int num_constants = constant_pool->length();
  if (num_constants > 0) {
    for (int i = 0; i < num_constants; ++i) {
      stream << kIndent;
      PrintConstant(stream, i::FixedArray::get(constant_pool, i, i_isolate()));
      stream << ",\n";
    }
  }
  stream << "]\n";
}

void BytecodeExpectationsPrinter::PrintCodeSnippet(
    std::ostream& stream, const std::string& body) const {
  stream << "snippet: \"\n";
  std::stringstream body_stream(body);
  std::string body_line;
  while (std::getline(body_stream, body_line)) {
    stream << kIndent;
    PrintEscapedString(stream, body_line);
    stream << '\n';
  }
  stream << "\"\n";
}

void BytecodeExpectationsPrinter::PrintHandlers(
    std::ostream& stream, i::Handle<i::BytecodeArray> bytecode_array) const {
  stream << "handlers: [\n";
  HandlerTable* table = HandlerTable::cast(bytecode_array->handler_table());
  for (int i = 0, num_entries = table->NumberOfRangeEntries(); i < num_entries;
       ++i) {
    stream << "  [" << table->GetRangeStart(i) << ", " << table->GetRangeEnd(i)
           << ", " << table->GetRangeHandler(i) << "],\n";
  }
  stream << "]\n";
}

void BytecodeExpectationsPrinter::PrintBytecodeArray(
    std::ostream& stream, i::Handle<i::BytecodeArray> bytecode_array) const {
  PrintFrameSize(stream, bytecode_array);
  PrintBytecodeSequence(stream, bytecode_array);
  PrintConstantPool(stream, bytecode_array->constant_pool());
  PrintHandlers(stream, bytecode_array);
}

void BytecodeExpectationsPrinter::PrintExpectation(
    std::ostream& stream, const std::string& snippet) const {
  std::string source_code =
      wrap_ ? WrapCodeInFunction(test_function_name_.c_str(), snippet)
            : snippet;

  v8::Local<v8::Script> script = Compile(source_code.c_str());

  if (execute_) Run(script);

  i::Handle<i::BytecodeArray> bytecode_array =
      top_level_ ? GetBytecodeArrayForScript(script)
                 : GetBytecodeArrayForGlobal(test_function_name_.c_str());

  stream << "---\n";
  PrintCodeSnippet(stream, snippet);
  PrintBytecodeArray(stream, bytecode_array);
  stream << '\n';
}

}  // namespace interpreter
}  // namespace internal
}  // namespace v8