commit | 1d8397141dcdbd52529dee354d578ab8d331a17d | [log] [tgz] |
---|---|---|
author | Joel Galenson <jgalenson@google.com> | Wed Dec 15 16:43:50 2021 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Wed Dec 15 16:43:50 2021 +0000 |
tree | d7d5a9f15f6a6c821c8083293ab544e57737121a | |
parent | ee34d9fa19870b568ec8f6f2fc3e141d5fa202e6 [diff] | |
parent | a91728d490ec7f24fd506b2d5de0c8fd6a5057a7 [diff] |
Merge "Refresh Android.bp, cargo2android.json, TEST_MAPPING." am: 7efe0cdee5 am: a91728d490 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/memoffset/+/1912096 Change-Id: I828e2c7c6563c1a16c5e16d6227bf7808089c166
C-Like offset_of
functionality for Rust structs.
Introduces the following macros:
offset_of!
for obtaining the offset of a member of a struct.offset_of_tuple!
for obtaining the offset of a member of a tuple. (Requires Rust 1.20+)span_of!
for obtaining the range that a field, or fields, span.memoffset
works under no_std
environments.
Add the following dependency to your Cargo.toml
:
[dependencies] memoffset = "0.6"
These versions will compile fine with rustc versions greater or equal to 1.19.
Add the following lines at the top of your main.rs
or lib.rs
files.
#[macro_use] extern crate memoffset;
#[macro_use] extern crate memoffset; #[repr(C, packed)] struct Foo { a: u32, b: u32, c: [u8; 5], d: u32, } fn main() { assert_eq!(offset_of!(Foo, b), 4); assert_eq!(offset_of!(Foo, d), 4+4+5); assert_eq!(span_of!(Foo, a), 0..4); assert_eq!(span_of!(Foo, a .. c), 0..8); assert_eq!(span_of!(Foo, a ..= c), 0..13); assert_eq!(span_of!(Foo, ..= d), 0..17); assert_eq!(span_of!(Foo, b ..), 4..17); }
memoffset
has experimental support for compile-time offset_of!
on a nightly compiler.
In order to use it, you must enable the unstable_const
crate feature and several compiler features.
Cargo.toml:
[dependencies.memoffset] version = "0.6" features = ["unstable_const"]
Your crate root: (lib.rs
/main.rs
)
#![feature(const_ptr_offset_from, const_maybe_uninit_as_ptr, const_raw_ptr_deref, const_refs_to_cell)]