Crate tblgen

source ·
Expand description

This crate provides raw bindings and a safe wrapper for TableGen, a domain-specific language used by the LLVM project.

The goal of this crate is to enable users to develop custom TableGen backends in Rust. Hence the primary use case of this crate are procedural macros that generate Rust code from TableGen description files.

Safety

This crate aims to be completely safe.

Supported LLVM Versions

An installation of LLVM is required to use this crate. This crate only aims to support the latest version of LLVM. The version of LLVM currently supported is 17.x.x.

The TABLEGEN_170_PREFIX environment variable can be used to specify a custom directory of the LLVM installation.

Examples

The following example parse simple TableGen code provided as a &str and iterates over classes and defs defined in this file.

use tblgen::{TableGenParser, RecordKeeper};

let keeper: RecordKeeper = TableGenParser::new()
    .add_source(
        r#"
        class A;
        def D: A;
        "#,
    )?
    .parse()?;
assert_eq!(keeper.classes().next().unwrap().0, Ok("A"));
assert_eq!(keeper.defs().next().unwrap().0, Ok("D"));
assert_eq!(keeper.all_derived_definitions("A").next().unwrap().name(), Ok("D"));

By adding include paths, external TableGen files can be included.

use tblgen::{TableGenParser, RecordKeeper};
use std::path::Path;

let keeper: RecordKeeper = TableGenParser::new()
    .add_source(r#"include "mlir/IR/OpBase.td""#)?
    .add_include_path(&format!("{}/include", std::env::var("TABLEGEN_170_PREFIX")?))
    .parse()?;
let i32_def = keeper.def("I32").expect("has I32 def");
assert!(i32_def.subclass_of("I"));
assert_eq!(i32_def.int_value("bitwidth"), Some(32));

API Stability

LLVM does not provide a stable C API for TableGen, and the C API provided by this crate is not stable. Furthermore, the safe wrapper does not provide a stable interface either, since this crate is still in early development.

Re-exports

Modules

  • error
    Module containing error types.
  • init
    TableGen initialization values. This module contains smart pointers that reference various Init types in TableGen.
  • raw
    This module contains raw bindings for TableGen. Note that these bindings are unstable and can change at any time.
  • record
    TableGen records and record values.
  • record_keeper
    TableGen record keeper.

Structs