bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Explain why (some) pointer/length strings are *const c_uchar

Browse source
This commit is contained in:
Zalathar 2024-12-12 20:41:01 +11:00
parent 5413d2bd6f
commit c3f2930edc
1 changed files with 12 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

12
compiler/rustc_codegen_llvm/src/llvm/ffi.rs
View file

@ -1,3 +1,15 @@
//! Bindings to the LLVM-C API (`LLVM*`), and to our own `extern "C"` wrapper
//! functions around the unstable LLVM C++ API (`LLVMRust*`).
//!
//! ## Passing pointer/length strings as `*const c_uchar`
//!
//! Normally it's a good idea for Rust-side bindings to match the corresponding
//! C-side function declarations as closely as possible. But when passing `&str`
//! or `&[u8]` data as a pointer/length pair, it's more convenient to declare
//! the Rust-side pointer as `*const c_uchar` instead of `*const c_char`.
//! Both pointer types have the same ABI, and using `*const c_uchar` avoids
//! the need for an extra cast from `*const u8` on the Rust side.
#![allow(non_camel_case_types)]
#![allow(non_upper_case_globals)]