Add support for custom per-field attributes #3307
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This adds the ability to apply custom Rust attributes to individual
struct, union, and newtype fields in generated bindings through three
mechanisms:
1. HTML annotations in C/C++ comments:
```c
/// <div rustbindgen attribute="serde(rename = x_coord)"></div>
int x;
```
2. ParseCallbacks::field_attributes() method for programmatic control:
```rust
fn field_attributes(&self, info: &FieldAttributeInfo) -> Vec<String>
```
3. CLI flag and Builder API for pattern-based attributes:
```bash
--field-attr "Point::x=serde(rename = x_coord)"
```
```rust
.field_attribute("Point", "x", "serde(rename = x_coord)")
```
All three mechanisms can be used together, with attributes merged in
order: annotations, callbacks, then CLI/Builder patterns.
This is useful for adding serde attributes, documentation, or other
derive-related metadata to specific fields.
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Summary: This includes 3 recent PRs: - rust-lang/rust-bindgen#3305 - Fix packed structs with flexible array members (merged) - rust-lang/rust-bindgen#3306 - Support nested flexible array members - rust-lang/rust-bindgen#3307 - Add support for custom per-field attributes The last one is specifically intended to allow per-field attributes from proc-macros to be applied. These have been cherry-picked onto the v0.72.1 release branch, as the main branch is still listed as v0.72.0 and I didn't want a backwards version step. The upstream branch is https://github.com/jsgf/rust-bindgen/tree/PR-merged Reviewed By: dtolnay Differential Revision: D85273915 fbshipit-source-id: 211916b9611cbfa409296a6854b4a94bba2c5195
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Summary: This includes 3 recent PRs: - rust-lang/rust-bindgen#3305 - Fix packed structs with flexible array members (merged) - rust-lang/rust-bindgen#3306 - Support nested flexible array members - rust-lang/rust-bindgen#3307 - Add support for custom per-field attributes The last one is specifically intended to allow per-field attributes from proc-macros to be applied. These have been cherry-picked onto the v0.72.1 release branch, as the main branch is still listed as v0.72.0 and I didn't want a backwards version step. The upstream branch is https://github.com/jsgf/rust-bindgen/tree/PR-merged Reviewed By: dtolnay Differential Revision: D85273915 fbshipit-source-id: 211916b9611cbfa409296a6854b4a94bba2c5195
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A single function gathers custom field attributes from cli, API and annotations, and then use it for both newtype and regular struct/union fields.
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This adds the ability to apply custom Rust attributes to individual
struct, union, and newtype fields in generated bindings through three
mechanisms:
--field-attr "Point::x=serde(rename = x_coord)"All three mechanisms can be used together, with attributes merged in
order: annotations, callbacks, then CLI/Builder patterns.
This is useful for adding serde attributes, documentation, or other
derive-related metadata to specific fields.