Feature: add namespace attribute support #1123
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Add support for `#[cbindgen::namespace = "..."]` attribute on functions to specify C++ namespaces. Features: - Parse attribute using `::` separator (e.g., "ffi::bar") - Group functions by namespace in C++ output - Emit nested namespace blocks inside extern "C" - Ignore attribute for C and Cython output - Add tests and documentation Co-authored-by: tarnishablec <[email protected]>
Changed from `#[cbindgen::namespace = "..."]` attribute syntax to
`/// cbindgen:namespace=...` doc comment annotation syntax.
The attribute syntax requires cbindgen to export a proc-macro, which
it doesn't. The doc comment annotation is the existing cbindgen way
to specify per-item configuration and doesn't cause Rust compilation
errors.
Example usage:
```rust
/// cbindgen:namespace=ffi::bar
#[no_mangle]
pub extern "C" fn foo(a: *const c_char) {}
```
Co-authored-by: tarnishablec <[email protected]>
Created a separate proc-macro crate that provides the `namespace`
attribute. This allows users to use the Rust attribute syntax:
```rust
#[cbindgen_macro::namespace = "ffi::bar"]
#[no_mangle]
pub extern "C" fn foo() {}
```
The attribute is a no-op at compile time but is parsed by cbindgen
to determine the C++ namespace for the generated header.
Changes:
- Created cbindgen-macro crate with `namespace` proc-macro attribute
- Updated utilities.rs to accept both `cbindgen::namespace` and
`cbindgen_macro::namespace` attribute paths
- Updated tests to use `cbindgen_macro::namespace` syntax
- Updated documentation with usage instructions
Co-authored-by: tarnishablec <[email protected]>
Changed the namespace attribute syntax from:
#[cbindgen_macro::namespace = "ffi::bar"]
to:
#[cbindgen_macro::namespace("ffi::bar")]
This change follows the function-like attribute syntax preferred by
the user.
Updated:
- cbindgen-macro proc-macro crate
- utilities.rs parsing logic to handle Meta::List instead of Meta::NameValue
- Test files to use the new syntax
- Documentation with the new syntax examples
Co-authored-by: tarnishablec <[email protected]>
Introduce a cbindgen-macro procedural macro crate and a #[cbindgen_macro::namespace("...")] attribute to specify C++ namespaces on individual extern "C" functions. Extend the internal function model to store optional namespace paths and update the C++ backend to group functions by namespace and emit nested namespace blocks inside the extern "C" region.
The new per-item namespace attribute takes precedence over the existing global namespace setting while preserving behavior for code that does not use the attribute. Add integration tests and documentation updates to cover both ffi:bar and ffi::bar style separators, verify precedence with global configuration, and ensure C output remains unchanged.
Co-authored-by: tarnishablec <[email protected]>
…support' into copilot/add-namespace-attribute-support
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This pull request introduces support for per-function C++ namespace specification in generated headers using a new procedural macro attribute, improving flexibility for organizing C++ bindings. The main changes include the creation of a new
cbindgen-macrocrate, parsing and storing per-function namespace attributes, updating the C++ code generation logic to group functions into nested namespaces, and comprehensive documentation and tests to demonstrate the feature.Procedural macro and attribute support
cbindgen-macrocrate, which provides the#[cbindgen_macro::namespace("...")]procedural macro attribute for specifying C++ namespaces for individual functions. The macro is a no-op at compile time but is parsed bycbindgenfor header generation. [1] [2] [3]Parsing and IR enhancements
Functionstruct insrc/bindgen/ir/function.rs) to store the per-function namespace parsed from the attribute, and added helper logic to extract this attribute from source code. [1] [2] [3] [4] [5]C++ code generation changes
src/bindgen/language_backend/clike.rs) so that functions with per-item namespace attributes are grouped and emitted within nested namespace blocks in generated headers. Functions without the attribute use the global or no namespace as before. [1] [2] [3]Documentation
Testing