code_generator

code_genrator 是一个由C++编写的C/C++语言代码生成器，支持struct、enum、函数、变量等等创建支持。使用对象方式进行创建，复用代码片段支持。

C++支持

• C++11

外部库

• fmtlib https://github.com/fmtlib/fmt

代码示例

1. struct 结构体创建

代码

StringCodeWriter writer;

auto person = struct_({
	field_("age", BuiltinType::Int),
	field_("name", array_(20, BuiltinType::Char))
}, "person");

person->write(writer);
std::cout << writer.str() << '\n';

生成输出

struct person {
  int age;
  char name[20];
}

2. function 函数创建

代码

StringCodeWriter writer;

auto fn = func_("print", BuiltinType::Void, { argument_("value", BuiltinType::Int) },
	{
		var_("tmp", BuiltinType::Int)->definition()->assign($("value")),
		$("std::cout << tmp << '\\n'")
	});

fn->write(writer);
std::cout << writer.str() << '\n';

生成输出

void print(int value) {
  int tmp = value;
  std::cout << tmp << '\n'
}

3. 结构体+编解码

代码

FunctionRef CreateEncodeFunc(StructRef stc, const char *fnName) {
    auto buffer = var_("buffer", type_("QByteArray"));
    auto rbuffer = var_("rbuffer", type_("QBuffer"));
    auto stream = var_("stream", type_("QDataStream"));
    auto callStatus = stream->call("status", {});

    auto personFields = stc->fields();
    Function::CodeContainer container;
    container += {
            buffer->definition(),
            rbuffer->definition()->construct(buffer->address()),
            rbuffer->call("open", { $("QBuffer::ReadWrite") }),
            stream->definition()->construct(rbuffer->address())
    };
    for (const auto &field : personFields) {
        FieldRef nfield = std::reinterpret_pointer_cast<Field>(field);
        container += {
                $("stream$s<<$s{}->{};", "thiz", nfield->name()),
                if_($("{}$s!=$sQDataStream::Ok", { callStatus }), {
                    return_("QByteArray()"),
                })
        };
    }
    container += return_(buffer->name());
    return func_(fnName, type_("QByteArray"), { argument_("thiz", ptr_(stc->declare())) }, container);
}

FunctionRef CreateDecodeFunc(StructRef stc, const char *fnName) {
    auto buffer = var_("buffer", type_("QByteArray"));
    auto stream = var_("stream", type_("QDataStream"));
    auto callStatus = stream->call("status", {});

    auto personFields = stc->fields();
    Function::CodeContainer decodeContainer;
    decodeContainer += (stream->definition()->construct(buffer));
    for (const auto &field : personFields) {
        FieldRef nfield = std::reinterpret_pointer_cast<Field>(field);
        decodeContainer += {
                $("stream$s>>$s{}->{};", "thiz", nfield->name()),
                if_($("{}$s!=$sQDataStream::Ok", { callStatus }), {
                        return_(""),
                })
        };
    }

    return func_(fnName, BuiltinType::Void, { argument_("thiz", ptr_(stc->declare())),
                                              argument_(buffer->name(), ref_(type_("QByteArray", const_()))) },
                 decodeContainer);
}

void ParseStruct() {
    StringCodeWriter writer;

    StructRef person = struct_({
        field_("age", BuiltinType::Int),
        field_("name", ptr_(BuiltinType::Char)),
        field_("salary", BuiltinType::Float),
        field_("address", ptr_(BuiltinType::Char))
    }, "person");

    auto encode = CreateEncodeFunc(person, "person_encode");
    auto decode = CreateDecodeFunc(person, "person_decode");

    person->write(writer);
    writer.writeString("\n");
    encode->write(writer);
    writer.writeString("\n");
    decode->write(writer);
    std::cout << writer.str() << '\n';
}

生成输出

struct person {
  int age;
  char* name;
  float salary;
  char* address;
}
QByteArray person_encode(struct person* thiz) {
  QByteArray buffer;
  QBuffer rbuffer(&buffer);
  rbuffer.open(QBuffer::ReadWrite);
  QDataStream stream(&rbuffer);
  stream << thiz->age;

  if (stream.status() != QDataStream::Ok) {
    return QByteArray();
  }
  stream << thiz->name;

  if (stream.status() != QDataStream::Ok) {
    return QByteArray();
  }
  stream << thiz->salary;

  if (stream.status() != QDataStream::Ok) {
    return QByteArray();
  }
  stream << thiz->address;

  if (stream.status() != QDataStream::Ok) {
    return QByteArray();
  }
  return buffer;
}
void person_decode(struct person* thiz, QByteArray buffer) {
  QDataStream stream(buffer);
  stream >> thiz->age;

  if (stream.status() != QDataStream::Ok) {
    return ;
  }
  stream >> thiz->name;

  if (stream.status() != QDataStream::Ok) {
    return ;
  }
  stream >> thiz->salary;

  if (stream.status() != QDataStream::Ok) {
    return ;
  }
  stream >> thiz->address;

  if (stream.status() != QDataStream::Ok) {
    return ;
  }
}

功能支持

• 代码片段复用
• 文件写入支持
• 类函数支持
• 构造函数支持
• 模板支持