bindgen-cli: alternate use of bindgen - v1 #12139
Draft
Commits on Nov 21, 2024
-
rust: integrate bindgen to generate rust bindings to C
Add a minimal integration of bindgen to the build. Bindgen is integrated at compile time with a "build.rs" file that for now only generates AppLayerEventType Rust bindings. This required some refactoring of the C so app-layer-events.h did not also include "rust.h", which causes issues for bindgen, probably related to circular references. AppLayerEventType was chosen as the first step as its an argument type some app-layer functions that we may want to use bindgen to export Rust, and one of the requirements of bindgen might be that C functions should only use datatypes defined in C, and not Rust. Following such a rule also prevents circular dependencies between Rust and C code. Bindgen generates the bindings in a file named "bindings.rs" in the target/ direction, which "sys.rs" will statically "include" at compiling name, making these bindings available under package "crate::sys". "build.rs" had to be placed in the non-standard location of "src/build.rs" (its usually alongside Cargo.toml) to satisfy the out-of-tree build requirements of distcheck. Note that bindgen is also available as a command line tool which could be used instead of integrating this at compile time, however the tool requires a newer version of Rust than our MSRV, and may present additional issues with respect to autoconf and distcheck.
-
app-layer: rename AppLayerEventType to SCAppLayerEventType
Follow the naming scheme for public exports.
-
app-layer: remove prototypes from decode.h
This lets us remove decode.h from app-layer-events.h as pulling in app-layer-events.h shouldn't result in pulling in dpdk, and other includes not related to app-layer-events. decode.h also doesn't need those forward declarations anymore due to previous changes.
-
bindgen: export SCAppLayerStateGetEventInfoByIdFn from C to Rust
Instead of defining this function pointer in type in Rust, and having it in C signatures, create a type and export it to Rust. To facilitate this, and new header has been creates, "app-layer-types.h", this is to avoid the circular reference of C headers pulling in "rust.h" which are required to generate Rust bindings.
-
bindgen: export AppProto and AppProtoEnum to Rust
This exposes the C define ALPROTO values to Rust without having to perform some runtime initialization with init_ffi. As app-layer-protos.h was clean of a circular reference to rust.h we could use it directly, it just needed the addition of suricata-common.h.
-
-
bindgen: use bindgen-cli instead of library
Replace bindgen usage from build.rs with the bindgen-cli program much like we use cbindgen. As bindgen can only accept one header file, we construct a pseudo-header file of all the headers that need to be consumed. Makefile dependency checking is done to make sure the pseudo-header is only generated as needed to avoid rebuilding every time. Special handling is required for Windows to use the Windows path.
-
bindgen: use --allowlist-type instead of --allowlist-item
The bindgen found in Ubuntu 24.04 and older is not new enough for --allowlist-item.
-
-
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.