crust

C/C++ to Rust transpiler

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Crust

Transpiler to convert the C/C++ code into rust.

C++ is a system programming language widely used in development of operating system, firmwares, device drivers and in some application development. Major drawback with C++ or any other system programming language is memory safety, null pointers and dangling pointers, which are very dangerous if not handled properly by the programmer. The new programming language Rust is system programming language provides the safe and secure programming with highly enforced compiler restrictions with zero cost abstraction.

This tool is intended to translate existing C++ code base into Rust with less effort. May require manual lookup or minute edit to the translated code.

Usage

First, make sure you are setup for Rust development. Check out http://www.rust-lang.org for more information. The installation sets up the Rust compiler and Cargo package management system. Also, it adds rustc and cargo commands to your PATH variable.

Now that you’re setup for rust. Open any suitable terminal and cd into the crust directory

Run cargo build to compile the entire project and download some dependencies.

Now, you many test out CRUST using some of the examples in the example folder as follows: cargo run

The program asks for the C/C++ file to be converted to Rust (Enter the path relative to the current location):

Enter the C/C++ file to be converted to Rust : examples/prog.cpp

Next, enter the translation mode, Strict or Loose (default is Loose). Strict mode assumes all variables to be immutable and Loose mode makes all variables mutable.

It also asks whether the program should be converted into a cargo project. It essentially sets up the program into a project with package management. Check out http://doc.crates.io/ for more information.

Enter the translation mode [(S/s)trict/(L/l)oose] : l
Do you want to create a cargo project :[Y/N] n

Now, it completes the translation and shows where the translated file is stored

Input file size : 177bytes
Tokenizing.......       :DONE
Invoking Parser ........        :DONE
Rust equivalent of source of `examples/prog.cpp` is generated successfully, View the rust code in file : ./examples/pro
g.rs

Alternatively, you may generate an executable similar to C executable as follows:

cargo build --release

This generates an executable, /target/release/crust which can be moved anywhere and run anytime using: ./crust

While executing this binary, the following options are available:

Options:
    -s, --strict        Strict mode (immutable)
    -p, --project-name  Cargo project name
    -h, --help          show this help message

Note that if the strict options are not applied, it implies loose mode.

Same options are available using the cargo build -- command. Options to CRUST must be entered after the --, while options to cargo must be entered before the --. It’s just easier to use the executable.

Crust will

  1. Convert the given C/C++ file with basic language construct into Rust.
  2. Preserve the comments,
  3. Run the formatter on the generated code.
  4. Convert to rust shorthand notion for return values.
  5. Document section where it failed to convert leaving out the original code as is.

Current limitation (haven’t implemented the parser for all features of C/C++)

  1. Convert the included header files yet.
  2. Convert function pointers yet.
  3. Analyse the types and choose an efficient type.

I’m still attempting make changes and redesign the parser to handle the code conversion.