From e7f8bf125c078004232e254e71b97226c4fed81b Mon Sep 17 00:00:00 2001 From: Josh Steadmon Date: Tue, 28 Jan 2025 14:01:38 -0800 Subject: libgit-sys: introduce Rust wrapper for libgit.a Introduce libgit-sys, a Rust wrapper crate that allows Rust code to call functions in libgit.a. This initial patch defines build rules and an interface that exposes user agent string getter functions as a proof of concept. This library can be tested with `cargo test`. In later commits, a higher-level library containing a more Rust-friendly interface will be added at `contrib/libgit-rs`. Symbols in libgit can collide with symbols from other libraries such as libgit2. We avoid this by first exposing library symbols in public_symbol_export.[ch]. These symbols are prepended with "libgit_" to avoid collisions and set to visible using a visibility pragma. In build.rs, Rust builds contrib/libgit-rs/libgit-sys/libgitpub.a, which also contains libgit.a and other dependent libraries, with -fvisibility=hidden to hide all symbols within those libraries that haven't been exposed with a visibility pragma. Co-authored-by: Kyle Lippincott Co-authored-by: Calvin Wan Signed-off-by: Calvin Wan Signed-off-by: Kyle Lippincott Signed-off-by: Josh Steadmon Signed-off-by: Junio C Hamano --- contrib/libgit-sys/src/lib.rs | 46 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 contrib/libgit-sys/src/lib.rs (limited to 'contrib/libgit-sys/src') diff --git a/contrib/libgit-sys/src/lib.rs b/contrib/libgit-sys/src/lib.rs new file mode 100644 index 0000000000..d4853f3074 --- /dev/null +++ b/contrib/libgit-sys/src/lib.rs @@ -0,0 +1,46 @@ +#[cfg(has_std__ffi__c_char)] +use std::ffi::c_char; + +#[cfg(not(has_std__ffi__c_char))] +#[allow(non_camel_case_types)] +pub type c_char = i8; + +extern crate libz_sys; + +extern "C" { + pub fn libgit_user_agent() -> *const c_char; + pub fn libgit_user_agent_sanitized() -> *const c_char; +} + +#[cfg(test)] +mod tests { + use std::ffi::CStr; + + use super::*; + + #[test] + fn user_agent_starts_with_git() { + let c_str = unsafe { CStr::from_ptr(libgit_user_agent()) }; + let agent = c_str + .to_str() + .expect("User agent contains invalid UTF-8 data"); + assert!( + agent.starts_with("git/"), + r#"Expected user agent to start with "git/", got: {}"#, + agent + ); + } + + #[test] + fn sanitized_user_agent_starts_with_git() { + let c_str = unsafe { CStr::from_ptr(libgit_user_agent_sanitized()) }; + let agent = c_str + .to_str() + .expect("Sanitized user agent contains invalid UTF-8 data"); + assert!( + agent.starts_with("git/"), + r#"Expected user agent to start with "git/", got: {}"#, + agent + ); + } +} -- cgit v1.2.3