go-cpp-transpiler

Description

This is the transpiler from Go source code to C++ source code written on Kotlin with the use of ANTLRv4.

From Go source code it builds an AST and then performs semantic analysis (typechecking). After that, it generates C++ source code.

How to use

To use the transpiler you need to have Java JRE installed on your device.

1. Clone this project
2. Run ./gradlew build
3. Run java -jar build/libs/jago.jar <path_to_go_code_file>

The last command has the following options:

1. You can specify just the path to Go source code file. Then the resulting C++ source code file will be generated in the current directory with name output-cpp.

   java -jar build/libs/jago.jar <path_to_go_code_file>

2. Besides the path to Go source code file you can also specify the path to resulting C++ source code file with the help of -o flag. If such file already exists it will be overriden.

   java -jar build/libs/jago.jar <path_to_go_code_file> -o <path_to_cpp_code_file>

Also, you can compile the resulting C++ source code:

1. Put C++ the resulting source code file to ./generated-cpp/src/main/cpp/.
2. Run ./gradlew generated-cpp:build
3. Then you can find a compiled executable file in subdirectory of ./generated-cpp/build/exe/main/

Support for Go language constructs

The following Go constructs are not supported since there is no analogy in C++

1. Goroutines
2. Channels
3. Slices

There are also features that is added to initial *Go grammar:

1. Function overloading.
2. Built-in to_string(x) function converts x to string. x must be of a base type: int, float64, bool, or pointer to these types.

Development process

Tools

• ANTLRv4 for generating a lexer and a parser for Go grammar.
• Kotlin as the main programming language
• Gradle as the main build tool
• JUnit 5 for testing the transpiler
• ShadowJar plugin for build a jar file

Process

1. During the Gradle build ANTLRv4 generates parser for input Go source code.
2. Generated parser creates Concrete Syntax Tree of the given Go source code.
3. Concrete Syntax Tree is converted to Abstract Syntax Tree.
4. During the sematic analysis typechecking stage happens.
5. Abstract Syntax Tree is translated to C++ source code.

Testing

Each stage is covered by tests. There are 76 tests in total.