diff options
| -rw-r--r-- | rust/Cargo.lock | 1 | ||||
| -rw-r--r-- | rust/hw/char/pl011/src/device.rs | 2 | ||||
| -rw-r--r-- | rust/qemu-api-macros/Cargo.toml | 2 | ||||
| -rw-r--r-- | rust/qemu-api-macros/src/lib.rs | 75 | ||||
| -rw-r--r-- | rust/qemu-api/Cargo.toml | 6 | ||||
| -rw-r--r-- | rust/qemu-api/build.rs | 9 | ||||
| -rw-r--r-- | rust/qemu-api/meson.build | 12 | ||||
| -rw-r--r-- | rust/qemu-api/src/device_class.rs | 8 | ||||
| -rw-r--r-- | rust/qemu-api/src/lib.rs | 4 | ||||
| -rw-r--r-- | rust/qemu-api/src/offset_of.rs | 161 | ||||
| -rw-r--r-- | rust/qemu-api/src/vmstate.rs | 10 | ||||
| -rw-r--r-- | rust/qemu-api/tests/tests.rs | 1 | ||||
| -rw-r--r-- | subprojects/packagefiles/syn-2-rs/meson.build | 1 |
13 files changed, 274 insertions, 18 deletions
diff --git a/rust/Cargo.lock b/rust/Cargo.lock index 9f43b33e8b..c0c6069247 100644 --- a/rust/Cargo.lock +++ b/rust/Cargo.lock @@ -93,6 +93,7 @@ name = "qemu_api" version = "0.1.0" dependencies = [ "qemu_api_macros", + "version_check", ] [[package]] diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs index 2d225d544d..bca727e37f 100644 --- a/rust/hw/char/pl011/src/device.rs +++ b/rust/hw/char/pl011/src/device.rs @@ -55,7 +55,7 @@ impl DeviceId { } #[repr(C)] -#[derive(Debug, qemu_api_macros::Object)] +#[derive(Debug, qemu_api_macros::Object, qemu_api_macros::offsets)] /// PL011 Device Model in QEMU pub struct PL011State { pub parent_obj: SysBusDevice, diff --git a/rust/qemu-api-macros/Cargo.toml b/rust/qemu-api-macros/Cargo.toml index f8d6d03609..a8f7377106 100644 --- a/rust/qemu-api-macros/Cargo.toml +++ b/rust/qemu-api-macros/Cargo.toml @@ -19,4 +19,4 @@ proc-macro = true [dependencies] proc-macro2 = "1" quote = "1" -syn = "2" +syn = { version = "2", features = ["extra-traits"] } diff --git a/rust/qemu-api-macros/src/lib.rs b/rust/qemu-api-macros/src/lib.rs index a4bc5d01ee..cf99ac04b8 100644 --- a/rust/qemu-api-macros/src/lib.rs +++ b/rust/qemu-api-macros/src/lib.rs @@ -3,8 +3,34 @@ // SPDX-License-Identifier: GPL-2.0-or-later use proc_macro::TokenStream; -use quote::quote; -use syn::{parse_macro_input, DeriveInput}; +use proc_macro2::Span; +use quote::{quote, quote_spanned}; +use syn::{ + parse_macro_input, parse_quote, punctuated::Punctuated, token::Comma, Data, DeriveInput, Field, + Fields, Ident, Type, Visibility, +}; + +struct CompileError(String, Span); + +impl From<CompileError> for proc_macro2::TokenStream { + fn from(err: CompileError) -> Self { + let CompileError(msg, span) = err; + quote_spanned! { span => compile_error!(#msg); } + } +} + +fn is_c_repr(input: &DeriveInput, msg: &str) -> Result<(), CompileError> { + let expected = parse_quote! { #[repr(C)] }; + + if input.attrs.iter().any(|attr| attr == &expected) { + Ok(()) + } else { + Err(CompileError( + format!("#[repr(C)] required for {}", msg), + input.ident.span(), + )) + } +} #[proc_macro_derive(Object)] pub fn derive_object(input: TokenStream) -> TokenStream { @@ -21,3 +47,48 @@ pub fn derive_object(input: TokenStream) -> TokenStream { TokenStream::from(expanded) } + +fn get_fields(input: &DeriveInput) -> Result<&Punctuated<Field, Comma>, CompileError> { + if let Data::Struct(s) = &input.data { + if let Fields::Named(fs) = &s.fields { + Ok(&fs.named) + } else { + Err(CompileError( + "Cannot generate offsets for unnamed fields.".to_string(), + input.ident.span(), + )) + } + } else { + Err(CompileError( + "Cannot generate offsets for union or enum.".to_string(), + input.ident.span(), + )) + } +} + +#[rustfmt::skip::macros(quote)] +fn derive_offsets_or_error(input: DeriveInput) -> Result<proc_macro2::TokenStream, CompileError> { + is_c_repr(&input, "#[derive(offsets)]")?; + + let name = &input.ident; + let fields = get_fields(&input)?; + let field_names: Vec<&Ident> = fields.iter().map(|f| f.ident.as_ref().unwrap()).collect(); + let field_types: Vec<&Type> = fields.iter().map(|f| &f.ty).collect(); + let field_vis: Vec<&Visibility> = fields.iter().map(|f| &f.vis).collect(); + + Ok(quote! { + ::qemu_api::with_offsets! { + struct #name { + #(#field_vis #field_names: #field_types,)* + } + } + }) +} + +#[proc_macro_derive(offsets)] +pub fn derive_offsets(input: TokenStream) -> TokenStream { + let input = parse_macro_input!(input as DeriveInput); + let expanded = derive_offsets_or_error(input).unwrap_or_else(Into::into); + + TokenStream::from(expanded) +} diff --git a/rust/qemu-api/Cargo.toml b/rust/qemu-api/Cargo.toml index e092f61e8f..cc716d75d4 100644 --- a/rust/qemu-api/Cargo.toml +++ b/rust/qemu-api/Cargo.toml @@ -16,9 +16,13 @@ categories = [] [dependencies] qemu_api_macros = { path = "../qemu-api-macros" } +[build-dependencies] +version_check = "~0.9" + [features] default = [] allocator = [] [lints.rust] -unexpected_cfgs = { level = "warn", check-cfg = ['cfg(MESON)', 'cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)'] } +unexpected_cfgs = { level = "warn", check-cfg = ['cfg(MESON)', 'cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)', + 'cfg(has_offset_of)'] } diff --git a/rust/qemu-api/build.rs b/rust/qemu-api/build.rs index 419b154c2d..20f8f718b9 100644 --- a/rust/qemu-api/build.rs +++ b/rust/qemu-api/build.rs @@ -4,6 +4,8 @@ use std::path::Path; +use version_check as rustc; + fn main() { if !Path::new("src/bindings.rs").exists() { panic!( @@ -11,4 +13,11 @@ fn main() { (`ninja bindings.rs`) and copy them to src/bindings.rs, or build through meson." ); } + + // Check for available rustc features + if rustc::is_min_version("1.77.0").unwrap_or(false) { + println!("cargo:rustc-cfg=has_offset_of"); + } + + println!("cargo:rerun-if-changed=build.rs"); } diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build index c950b008d5..6f637af7b1 100644 --- a/rust/qemu-api/meson.build +++ b/rust/qemu-api/meson.build @@ -1,3 +1,9 @@ +_qemu_api_cfg = ['--cfg', 'MESON'] +# _qemu_api_cfg += ['--cfg', 'feature="allocator"'] +if rustc.version().version_compare('>=1.77.0') + _qemu_api_cfg += ['--cfg', 'has_offset_of'] +endif + _qemu_api_rs = static_library( 'qemu_api', structured_sources( @@ -6,6 +12,7 @@ _qemu_api_rs = static_library( 'src/c_str.rs', 'src/definitions.rs', 'src/device_class.rs', + 'src/offset_of.rs', 'src/vmstate.rs', 'src/zeroable.rs', ], @@ -13,10 +20,7 @@ _qemu_api_rs = static_library( ), override_options: ['rust_std=2021', 'build.rust_std=2021'], rust_abi: 'rust', - rust_args: [ - '--cfg', 'MESON', - # '--cfg', 'feature="allocator"', - ], + rust_args: _qemu_api_cfg, ) rust.test('rust-qemu-api-tests', _qemu_api_rs, diff --git a/rust/qemu-api/src/device_class.rs b/rust/qemu-api/src/device_class.rs index cb4573ca6e..56608c7f7f 100644 --- a/rust/qemu-api/src/device_class.rs +++ b/rust/qemu-api/src/device_class.rs @@ -23,23 +23,23 @@ macro_rules! device_class_init { #[macro_export] macro_rules! define_property { - ($name:expr, $state:ty, $field:expr, $prop:expr, $type:expr, default = $defval:expr$(,)*) => { + ($name:expr, $state:ty, $field:ident, $prop:expr, $type:expr, default = $defval:expr$(,)*) => { $crate::bindings::Property { // use associated function syntax for type checking name: ::std::ffi::CStr::as_ptr($name), info: $prop, - offset: ::core::mem::offset_of!($state, $field) as isize, + offset: $crate::offset_of!($state, $field) as isize, set_default: true, defval: $crate::bindings::Property__bindgen_ty_1 { u: $defval as u64 }, ..$crate::zeroable::Zeroable::ZERO } }; - ($name:expr, $state:ty, $field:expr, $prop:expr, $type:expr$(,)*) => { + ($name:expr, $state:ty, $field:ident, $prop:expr, $type:expr$(,)*) => { $crate::bindings::Property { // use associated function syntax for type checking name: ::std::ffi::CStr::as_ptr($name), info: $prop, - offset: ::core::mem::offset_of!($state, $field) as isize, + offset: $crate::offset_of!($state, $field) as isize, set_default: false, ..$crate::zeroable::Zeroable::ZERO } diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs index e6bd953e10..aa8d16ec94 100644 --- a/rust/qemu-api/src/lib.rs +++ b/rust/qemu-api/src/lib.rs @@ -32,6 +32,7 @@ unsafe impl Sync for bindings::VMStateInfo {} pub mod c_str; pub mod definitions; pub mod device_class; +pub mod offset_of; pub mod vmstate; pub mod zeroable; @@ -169,3 +170,6 @@ unsafe impl GlobalAlloc for QemuAllocator { } } } + +#[cfg(has_offset_of)] +pub use core::mem::offset_of; diff --git a/rust/qemu-api/src/offset_of.rs b/rust/qemu-api/src/offset_of.rs new file mode 100644 index 0000000000..075e98f986 --- /dev/null +++ b/rust/qemu-api/src/offset_of.rs @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: MIT + +/// This macro provides the same functionality as `core::mem::offset_of`, +/// except that only one level of field access is supported. The declaration +/// of the struct must be wrapped with `with_offsets! { }`. +/// +/// It is needed because `offset_of!` was only stabilized in Rust 1.77. +#[cfg(not(has_offset_of))] +#[macro_export] +macro_rules! offset_of { + ($Container:ty, $field:ident) => { + <$Container>::OFFSET_TO__.$field + }; +} + +/// A wrapper for struct declarations, that allows using `offset_of!` in +/// versions of Rust prior to 1.77 +#[macro_export] +macro_rules! with_offsets { + // This method to generate field offset constants comes from: + // + // https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=10a22a9b8393abd7b541d8fc844bc0df + // + // used under MIT license with permission of Yandros aka Daniel Henry-Mantilla + ( + $(#[$struct_meta:meta])* + $struct_vis:vis + struct $StructName:ident { + $( + $(#[$field_meta:meta])* + $field_vis:vis + $field_name:ident : $field_ty:ty + ),* + $(,)? + } + ) => ( + #[cfg(not(has_offset_of))] + const _: () = { + struct StructOffsetsHelper<T>(std::marker::PhantomData<T>); + const END_OF_PREV_FIELD: usize = 0; + + // populate StructOffsetsHelper<T> with associated consts, + // one for each field + $crate::with_offsets! { + @struct $StructName + @names [ $($field_name)* ] + @tys [ $($field_ty ,)*] + } + + // now turn StructOffsetsHelper<T>'s consts into a single struct, + // applying field visibility. This provides better error messages + // than if offset_of! used StructOffsetsHelper::<T> directly. + pub + struct StructOffsets { + $( + $field_vis + $field_name: usize, + )* + } + impl $StructName { + pub + const OFFSET_TO__: StructOffsets = StructOffsets { + $( + $field_name: StructOffsetsHelper::<$StructName>::$field_name, + )* + }; + } + }; + ); + + ( + @struct $StructName:ident + @names [] + @tys [] + ) => (); + + ( + @struct $StructName:ident + @names [$field_name:ident $($other_names:tt)*] + @tys [$field_ty:ty , $($other_tys:tt)*] + ) => ( + #[allow(non_local_definitions)] + #[allow(clippy::modulo_one)] + impl StructOffsetsHelper<$StructName> { + #[allow(nonstandard_style)] + const $field_name: usize = { + const ALIGN: usize = std::mem::align_of::<$field_ty>(); + const TRAIL: usize = END_OF_PREV_FIELD % ALIGN; + END_OF_PREV_FIELD + (if TRAIL == 0 { 0usize } else { ALIGN - TRAIL }) + }; + } + const _: () = { + const END_OF_PREV_FIELD: usize = + StructOffsetsHelper::<$StructName>::$field_name + + std::mem::size_of::<$field_ty>() + ; + $crate::with_offsets! { + @struct $StructName + @names [$($other_names)*] + @tys [$($other_tys)*] + } + }; + ); +} + +#[cfg(test)] +mod tests { + use crate::offset_of; + + #[repr(C)] + struct Foo { + a: u16, + b: u32, + c: u64, + d: u16, + } + + #[repr(C)] + struct Bar { + pub a: u16, + pub b: u64, + c: Foo, + d: u64, + } + + crate::with_offsets! { + #[repr(C)] + struct Bar { + pub a: u16, + pub b: u64, + c: Foo, + d: u64, + } + } + + #[repr(C)] + pub struct Baz { + b: u32, + a: u8, + } + crate::with_offsets! { + #[repr(C)] + pub struct Baz { + b: u32, + a: u8, + } + } + + #[test] + fn test_offset_of() { + const OFFSET_TO_C: usize = offset_of!(Bar, c); + + assert_eq!(offset_of!(Bar, a), 0); + assert_eq!(offset_of!(Bar, b), 8); + assert_eq!(OFFSET_TO_C, 16); + assert_eq!(offset_of!(Bar, d), 40); + + assert_eq!(offset_of!(Baz, b), 0); + assert_eq!(offset_of!(Baz, a), 4); + } +} diff --git a/rust/qemu-api/src/vmstate.rs b/rust/qemu-api/src/vmstate.rs index 9c252ce18e..bedcf1e8f3 100644 --- a/rust/qemu-api/src/vmstate.rs +++ b/rust/qemu-api/src/vmstate.rs @@ -58,7 +58,7 @@ macro_rules! vmstate_single_test { .as_bytes() .as_ptr() as *const ::std::os::raw::c_char, err_hint: ::core::ptr::null(), - offset: ::core::mem::offset_of!($struct_name, $field_name), + offset: $crate::offset_of!($struct_name, $field_name), size: $size, start: 0, num: 0, @@ -135,7 +135,7 @@ macro_rules! vmstate_array { .as_bytes() .as_ptr() as *const ::std::os::raw::c_char, err_hint: ::core::ptr::null(), - offset: ::core::mem::offset_of!($struct_name, $field_name), + offset: $crate::offset_of!($struct_name, $field_name), size: $size, start: 0, num: $length as _, @@ -183,7 +183,7 @@ macro_rules! vmstate_struct_pointer_v { .as_bytes() .as_ptr() as *const ::std::os::raw::c_char, err_hint: ::core::ptr::null(), - offset: ::core::mem::offset_of!($struct_name, $field_name), + offset: $crate::offset_of!($struct_name, $field_name), size: ::core::mem::size_of::<*const $type>(), start: 0, num: 0, @@ -212,7 +212,7 @@ macro_rules! vmstate_array_of_pointer { info: unsafe { $info }, size: ::core::mem::size_of::<*const $type>(), flags: VMStateFlags(VMStateFlags::VMS_ARRAY.0 | VMStateFlags::VMS_ARRAY_OF_POINTER.0), - offset: ::core::mem::offset_of!($struct_name, $field_name), + offset: $crate::offset_of!($struct_name, $field_name), err_hint: ::core::ptr::null(), start: 0, num_offset: 0, @@ -241,7 +241,7 @@ macro_rules! vmstate_array_of_pointer_to_struct { | VMStateFlags::VMS_STRUCT.0 | VMStateFlags::VMS_ARRAY_OF_POINTER.0, ), - offset: ::core::mem::offset_of!($struct_name, $field_name), + offset: $crate::offset_of!($struct_name, $field_name), err_hint: ::core::ptr::null(), start: 0, num_offset: 0, diff --git a/rust/qemu-api/tests/tests.rs b/rust/qemu-api/tests/tests.rs index 381ac84657..7442f69564 100644 --- a/rust/qemu-api/tests/tests.rs +++ b/rust/qemu-api/tests/tests.rs @@ -21,6 +21,7 @@ fn test_device_decl_macros() { ..Zeroable::ZERO }; + #[derive(qemu_api_macros::offsets)] #[repr(C)] #[derive(qemu_api_macros::Object)] pub struct DummyState { diff --git a/subprojects/packagefiles/syn-2-rs/meson.build b/subprojects/packagefiles/syn-2-rs/meson.build index a53335f309..9f56ce1c24 100644 --- a/subprojects/packagefiles/syn-2-rs/meson.build +++ b/subprojects/packagefiles/syn-2-rs/meson.build @@ -24,6 +24,7 @@ _syn_rs = static_library( '--cfg', 'feature="printing"', '--cfg', 'feature="clone-impls"', '--cfg', 'feature="proc-macro"', + '--cfg', 'feature="extra-traits"', ], dependencies: [ quote_dep, |