tree-sitter-c2rust (with parser compatibility)

This repo allows you link tree-sitter, as well as a parser to a Rust WebAssembly project.

You'll need

• emscripten (emcc)
• mesonbuild
• c2rust
• A unix based environment (This procedure has been tested under a Linux machine)

Steps

a. Compile the parser you want with tree-sitter generate

b. Move the parser from src/parser.c, into this library at lib/src/imported_parser.c

1. If The parser has a scanner.c, move that into lib/src/imported_scanner.c

c. In the imported_parser.c file (and in the imported_scanner.c file), change all the tree-sitter includes to be local

- #include "tree-sitter/parser.h"
+ #include "parser.h"

1. If you have an imported_scanner.c, include that in the parser file

+ #include "imported_scanner.c"

d. Compile a compile_commands.json

meson setup build --buildtype=release --cross-file=wasm.txt --default-library=static

e. Run the transpiler

bash transpile.sh

f. Run cargo check, there should be a small amount of errors. Fix them

1. There is one error with an easy fix that is consistent.

error[E0425]: cannot find value `run_static_initializers` in this scope
      --> lib/binding_rust/core_wrapper/core/api_raw.rs:303148:51
       |
303148 | static INIT_ARRAY: [unsafe extern "C" fn(); 1] = [run_static_initializers];
       |                                                   ^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
       |

In both api_raw.rs and imported_parser.rs, delete this INIT_ARRAY and associated attributes above it. Under imported_parser.rs, in the tree_sitter_xxx() function, before the return &language statement, put run_static_initializers()

pub unsafe extern "C" fn tree_sitter_xxxx() -> *const TSLanguage {
+   run_static_initializers();
    return &language;
}

g. Profit! Include new tree-sitter in your project

tree-sitter = { path = "tree-sitter/lib" }

Add your language like so, and use tree-sitter as you normally would!

let lang = unsafe { tree_sitter::Language::from_raw(tree_sitter::core::tree_sitter_xxxx()) };