opaque-pointer-rs
Generic functions to work with opaque pointers when use FFI to expose Rust structs
Basic usage
With this crate you can manage raw pointers easily to expose structs
that will be
use as opaque pointers from C or C++ calling to Rust functions to use it. This
can be used with cbindgen crate with option parse.parse_deps = true
for it will generate opaque C/C++ structs
to use pointers in the arguments.
You can find more information about using Rust from other languages in The Rust FFI Omnibus objects section of Jake Goulding.
Examples
Creating FFIs to use a Rust's struct
methods from C or C++:
/// Ownership will NOT control the heap-allocated memory until own it back.
pub extern
/// Drop (free memory of) Rust's TestIt object as usually.
pub extern
pub extern
pub extern
The previous example is compiled when tests are run. If you have an error with that code, please, open a issue.
Features
std
: activated by default, it is required for c-types FFI.alloc
: required if compile without std.c-types
: FFI for C types, requires std feature.panic-if-null
: it will check if a pointer is null to panic before to use it.
Panic & unwind in FFI functions
See comment in Rust issue #58794 and Rust issue #58760:
The default was changed to abort-by-default in extern functions in this PR. This is tracking the stabilization of the #[unwind(allowed)] (and #[unwind(abort)]) attributes.
Also Rust pull request #55982:
This PR changes the behavior of generated code to be sound-by-default. If an extern fn is unwound (panicked through) then it immediately aborts the program. Put another way, no extern fn can unwind.
And Rust issue #52652:
This UB is not mentioned in any later release notes.