The transpiler module is invoked using the transpile sub-command of c2rust:

c2rust transpile [args] compile_commands.json [-- extra-clang-args]

The following arguments control the basic transpiler behavior:

• --emit-modules - Emit each translated Rust file as a module (the default is to make each file its own crate).
• --fail-on-error - Fail instead of warning if a source file cannot be fully translated.
• --reduce-type-annotations - Do not emit explicit type annotations when unnecessary.
• --translate-asm - Translate C inline assembly into corresponding Rust inline assembly. The translated assembly is unlikely to work as-is due to differences between GCC and LLVM (used in Rust) inline assembly styles, but it can provide a starting point for manual translation.
• -f <regex>, --filter <regex> - Only translate files based on the regular expression used.

The transpiler can create skeleton cargo build files for the translated Rust sources, controlled by the following options:

• -e, --emit-build-files - Emit cargo build files to build the translated Rust code as a library. Build files are emitted in the directory specified by --output-dir, or if not specified, the directory containing compile_commands.json. This will not overwrite existing files, so remove these build files before re-creating build files. (implies --emit-modules)
• -m <main_module>, --main <main_module> - Emit cargo build files to build the translated Rust code as a binary. The main function must be found in the specified module (C source file) <main_module>. <main_module> should be the bare module name, not including the .rs extension. Build files are emitted in the directory specified by --output-dir, or if not specified, the directory containing compile_commands.json. This will not overwrite existing files, so remove this build file directory before re-creating build files. (implies --emit-build-files)

The transpiler can instrument the transpiled Rust code for cross-checking. The following options control this instrumentation:

• -x, --cross-checks - Add macros and build files for cross-checking.
• --use-fakechecks - Link against the fakechecks library for cross-checking instead of using the default online checks.
• -X <config>, --cross-check-config <config> - Use the given config file as the cross-checking config.

The c2rust-transpile library uses the c2rust-ast-exporter library to translate C code to Rust. The ast-exporter library links against the native clang compiler front end to parse C code and exports the AST for use in the transpiler, which is then implemented purely in Rust.