LLVM Codegen Utils

A Rust library to facilitate targeting LLVM, providing a mostly safe interface with support for multiple LLVM versions.

Note: Handles currently do not accurately represent their ownership.

Features

• Safe(r) interface over raw LLVM bindings
• Support for multiple LLVM versions (19, 18, 20, 21)
• Type-safe builders, values, types, and basic blocks
• Automatic resource management through custom handle types

Supported LLVM Versions

LLVM Version	Feature Flag	llvm-sys Version
LLVM 19	llvm-sys-190	^191
LLVM 18	llvm-sys-180	^181
LLVM 20	llvm-sys-200	^201
LLVM 21	llvm-sys-210	^211

Workspace Structure

This repository is organized as a Cargo workspace containing the following crates:

px-llvm-codegen-utils-core

The core library providing safe abstractions over LLVM. It includes:

• Ctx - LLVM context wrapper
• Mod - LLVM module wrapper
• Value / ValueKind - Type-safe value representations
• Func - Function value wrapper
• BB - Basic block wrapper
• Ty - Type wrapper with constructors for int, pointer, struct, and function types
• Builder - IR builder with methods for common instructions (alloca, load, store, arithmetic, branching, etc.)
• LLHandle - Smart handle type for LLVM resources with automatic cleanup

px-llvm-codegen-utils-info

Contains compile-time information about supported LLVM versions. Exports the LLVMS constant which maps LLVM version identifiers to their corresponding llvm-sys crate versions.

px-llvm-codegen-utils-version-macros

Provides the vers! macro for writing version-polymorphic code that works across different LLVM versions. This macro expands code conditionally based on enabled LLVM version features.

llvm-codegen-utils-maintenance

Internal maintenance tool for managing the workspace. Handles:

• Generating LLVM version-specific Cargo.toml entries
• Synchronizing version numbers across crates
• Publishing crates to crates.io

Usage

Add the core crate to your Cargo.toml with the desired LLVM version feature:

[dependencies]
px-llvm-codegen-utils-core = { version = "0.1", features = ["llvm-sys-190"] }

Comparison with inkwell

Aspect	inkwell	LLVM Codegen Utils
API Style	Direct LLVM bindings	Higher-level, cleaned interface
LLVM Support	LLVM 18 and lower	LLVM 18 and higher
Multi-version	Single version per build	Multiple versions via features

inkwell exposes, safely, the actual, non-modified, LLVM API. LLVM Codegen Utils exposes and/or wraps the API to present a safe interface, at the cost of using a slightly higher-level and/or cleaned interface.

License

This project is licensed under CC0-1.0.