macros: add spirv_vector attribute macro for declaring spirv Vector types

Author: Firestar99

crates/spirv-std/macros/src/lib.rs

@@ -81,8 +81,11 @@ mod spirv_attr_version;
 use crate::debug_printf::{DebugPrintfInput, debug_printf_inner};
 use crate::spirv_attr_version::spirv_attr_with_version;
 use proc_macro::TokenStream;
-use proc_macro2::{Delimiter, Group, TokenTree};
+use proc_macro2::{Delimiter, Group, TokenStream as TokenStream2, TokenTree};
 use quote::{ToTokens, TokenStreamExt, format_ident, quote};
+use syn::punctuated::Punctuated;
+use syn::spanned::Spanned;
+use syn::{GenericParam, Token};
 
 /// A macro for creating SPIR-V `OpTypeImage` types. Always produces a
 /// `spirv_std::image::Image<...>` type.
@@ -267,3 +270,51 @@ pub fn debug_printfln(input: TokenStream) -> TokenStream {
 pub fn gen_sample_param_permutations(_attr: TokenStream, item: TokenStream) -> TokenStream {
     sample_param_permutations::gen_sample_param_permutations(item)
 }
+
+#[proc_macro_attribute]
+pub fn spirv_vector(attr: TokenStream, item: TokenStream) -> TokenStream {
+    spirv_vector_impl(attr.into(), item.into())
+        .unwrap_or_else(syn::Error::into_compile_error)
+        .into()
+}
+
+fn spirv_vector_impl(attr: TokenStream2, item: TokenStream2) -> syn::Result<TokenStream2> {
+    // Whenever we'll properly resolve the crate symbol, replace this.
+    let spirv_std = quote!(spirv_std);
+
+    // Defer all validation to our codegen backend. Rather than erroring here, emit garbage.
+    let item = syn::parse2::<syn::ItemStruct>(item)?;
+    let ident = &item.ident;
+    let gens = &item.generics.params;
+    let gen_refs = &item
+        .generics
+        .params
+        .iter()
+        .map(|p| match p {
+            GenericParam::Lifetime(p) => p.lifetime.to_token_stream(),
+            GenericParam::Type(p) => p.ident.to_token_stream(),
+            GenericParam::Const(p) => p.ident.to_token_stream(),
+        })
+        .collect::<Punctuated<_, Token![,]>>();
+    let where_clause = &item.generics.where_clause;
+    let element = item
+        .fields
+        .iter()
+        .next()
+        .ok_or_else(|| syn::Error::new(item.span(), "Vector ZST not allowed"))?
+        .ty
+        .to_token_stream();
+    let count = item.fields.len();
+
+    Ok(quote! {
+        #[cfg_attr(target_arch = "spirv", rust_gpu::vector::v1(#attr))]
+        #item
+
+        unsafe impl<#gens> #spirv_std::vector::VectorOrScalar for #ident<#gen_refs> #where_clause {
+            type Scalar = #element;
+            const DIM: core::num::NonZeroUsize = core::num::NonZeroUsize::new(#count).unwrap();
+        }
+
+        unsafe impl<#gens> #spirv_std::vector::Vector<#element, #count> for #ident<#gen_refs> #where_clause {}
+    })
+}

crates/spirv-std/src/lib.rs

@@ -87,7 +87,7 @@
 /// Public re-export of the `spirv-std-macros` crate.
 #[macro_use]
 pub extern crate spirv_std_macros as macros;
-pub use macros::spirv;
+pub use macros::{spirv, spirv_vector};
 
 pub mod arch;
 pub mod byte_addressable_buffer;

crates/spirv-std/src/vector.rs

@@ -18,9 +18,10 @@ pub unsafe trait VectorOrScalar: Copy + Default + Send + Sync + 'static {
 
 /// Abstract trait representing a SPIR-V vector type.
 ///
-/// To implement this trait, your struct must be marked with:
+/// To derive this trait, mark your struct with:
 /// ```no_run
-/// #[cfg_attr(target_arch = "spirv", rust_gpu::vector::v1)]
+/// #[spirv_std::spirv_vector]
+/// # #[derive(Copy, Clone, Default)]
 /// # struct Bla(f32, f32);
 /// ```
 ///
@@ -43,8 +44,8 @@ pub unsafe trait VectorOrScalar: Copy + Default + Send + Sync + 'static {
 ///
 /// # Example
 /// ```no_run
+/// #[spirv_std::spirv_vector]
 /// #[derive(Copy, Clone, Default)]
-/// #[cfg_attr(target_arch = "spirv", rust_gpu::vector::v1)]
 /// struct MyColor {
 ///     r: f32,
 ///     b: f32,
@@ -55,7 +56,8 @@ pub unsafe trait VectorOrScalar: Copy + Default + Send + Sync + 'static {
 ///
 /// # Safety
 /// Must only be implemented on types that the spirv codegen emits as valid `OpTypeVector`. This includes all structs
-/// marked with `#[rust_gpu::vector::v1]`, like [`glam`]'s non-SIMD "scalar" vector types.
+/// marked with `#[rust_gpu::vector::v1]`, which `#[spirv_std::spirv_vector]` expands into or [`glam`]'s non-SIMD
+/// "scalar" vector types use directly.
 pub unsafe trait Vector<T: Scalar, const N: usize>: VectorOrScalar<Scalar = T> {}
 
 macro_rules! impl_vector {

tests/compiletests/ui/glam/invalid_vector_type_macro.rs

@@ -0,0 +1,33 @@
+// build-fail
+
+use core::num::NonZeroU32;
+use spirv_std::glam::Vec2;
+use spirv_std::spirv;
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone, Default)]
+pub struct FewerFields {
+    _v: f32,
+}
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone, Default)]
+pub struct TooManyFields {
+    _x: f32,
+    _y: f32,
+    _z: f32,
+    _w: f32,
+    _v: f32,
+}
+
+// wrong member types fails too early
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone, Default)]
+pub struct DifferentTypes {
+    _x: f32,
+    _y: u32,
+}
+
+#[spirv(fragment)]
+pub fn entry(_: FewerFields, _: TooManyFields, #[spirv(flat)] _: DifferentTypes) {}

tests/compiletests/ui/glam/invalid_vector_type_macro.stderr

@@ -0,0 +1,20 @@
+error: `#[spirv(vector)]` must have 2, 3 or 4 members
+ --> $DIR/invalid_vector_type_macro.rs:9:1
+  |
+9 | pub struct FewerFields {
+  | ^^^^^^^^^^^^^^^^^^^^^^
+
+error: `#[spirv(vector)]` must have 2, 3 or 4 members
+  --> $DIR/invalid_vector_type_macro.rs:15:1
+   |
+15 | pub struct TooManyFields {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `#[spirv(vector)]` member types must all be the same
+  --> $DIR/invalid_vector_type_macro.rs:27:1
+   |
+27 | pub struct DifferentTypes {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+

tests/compiletests/ui/glam/invalid_vector_type_macro2.rs

@@ -0,0 +1,42 @@
+// build-fail
+// normalize-stderr-test "\S*/crates/spirv-std/src/" -> "$$SPIRV_STD_SRC/"
+
+use core::num::NonZeroU32;
+use spirv_std::glam::Vec2;
+use spirv_std::spirv;
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone, Default)]
+pub struct ZstVector;
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone, Default)]
+pub struct NotVectorField {
+    _x: Vec2,
+    _y: Vec2,
+}
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone)]
+pub struct NotVectorField2 {
+    _x: NonZeroU32,
+    _y: NonZeroU32,
+}
+
+impl Default for NotVectorField2 {
+    fn default() -> Self {
+        Self {
+            _x: NonZeroU32::new(1).unwrap(),
+            _y: NonZeroU32::new(1).unwrap(),
+        }
+    }
+}
+
+#[spirv(fragment)]
+pub fn entry(
+    // workaround to ZST loading
+    #[spirv(storage_class, descriptor_set = 0, binding = 0)] _: &(ZstVector, i32),
+    _: NotVectorField,
+    #[spirv(flat)] _: NotVectorField2,
+) {
+}

tests/compiletests/ui/glam/invalid_vector_type_macro2.stderr

@@ -0,0 +1,113 @@
+error: Vector ZST not allowed
+  --> $DIR/invalid_vector_type_macro2.rs:9:1
+   |
+9  | / #[derive(Copy, Clone, Default)]
+10 | | pub struct ZstVector;
+   | |_____________________^
+
+error[E0412]: cannot find type `ZstVector` in this scope
+  --> $DIR/invalid_vector_type_macro2.rs:38:67
+   |
+38 |     #[spirv(storage_class, descriptor_set = 0, binding = 0)] _: &(ZstVector, i32),
+   |                                                                   ^^^^^^^^^ not found in this scope
+
+error: unknown argument to spirv attribute
+  --> $DIR/invalid_vector_type_macro2.rs:38:13
+   |
+38 |     #[spirv(storage_class, descriptor_set = 0, binding = 0)] _: &(ZstVector, i32),
+   |             ^^^^^^^^^^^^^
+
+error[E0277]: the trait bound `Vec2: Scalar` is not satisfied
+  --> $DIR/invalid_vector_type_macro2.rs:15:9
+   |
+15 |     _x: Vec2,
+   |         ^^^^ the trait `Scalar` is not implemented for `Vec2`
+   |
+   = help: the following other types implement trait `Scalar`:
+             bool
+             f32
+             f64
+             i16
+             i32
+             i64
+             i8
+             u16
+           and 3 others
+note: required by a bound in `spirv_std::vector::VectorOrScalar::Scalar`
+  --> $SPIRV_STD_SRC/vector.rs:13:18
+   |
+13 |     type Scalar: Scalar;
+   |                  ^^^^^^ required by this bound in `VectorOrScalar::Scalar`
+
+error[E0277]: the trait bound `Vec2: Scalar` is not satisfied
+  --> $DIR/invalid_vector_type_macro2.rs:12:1
+   |
+12 | #[spirv_std::spirv_vector]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Scalar` is not implemented for `Vec2`
+   |
+   = help: the following other types implement trait `Scalar`:
+             bool
+             f32
+             f64
+             i16
+             i32
+             i64
+             i8
+             u16
+           and 3 others
+note: required by a bound in `Vector`
+  --> $SPIRV_STD_SRC/vector.rs:60:28
+   |
+60 | pub unsafe trait Vector<T: Scalar, const N: usize>: VectorOrScalar<Scalar = T> {}
+   |                            ^^^^^^ required by this bound in `Vector`
+   = note: this error originates in the attribute macro `spirv_std::spirv_vector` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `NonZero<u32>: Scalar` is not satisfied
+  --> $DIR/invalid_vector_type_macro2.rs:22:9
+   |
+22 |     _x: NonZeroU32,
+   |         ^^^^^^^^^^ the trait `Scalar` is not implemented for `NonZero<u32>`
+   |
+   = help: the following other types implement trait `Scalar`:
+             bool
+             f32
+             f64
+             i16
+             i32
+             i64
+             i8
+             u16
+           and 3 others
+note: required by a bound in `spirv_std::vector::VectorOrScalar::Scalar`
+  --> $SPIRV_STD_SRC/vector.rs:13:18
+   |
+13 |     type Scalar: Scalar;
+   |                  ^^^^^^ required by this bound in `VectorOrScalar::Scalar`
+
+error[E0277]: the trait bound `NonZero<u32>: Scalar` is not satisfied
+  --> $DIR/invalid_vector_type_macro2.rs:19:1
+   |
+19 | #[spirv_std::spirv_vector]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Scalar` is not implemented for `NonZero<u32>`
+   |
+   = help: the following other types implement trait `Scalar`:
+             bool
+             f32
+             f64
+             i16
+             i32
+             i64
+             i8
+             u16
+           and 3 others
+note: required by a bound in `Vector`
+  --> $SPIRV_STD_SRC/vector.rs:60:28
+   |
+60 | pub unsafe trait Vector<T: Scalar, const N: usize>: VectorOrScalar<Scalar = T> {}
+   |                            ^^^^^^ required by this bound in `Vector`
+   = note: this error originates in the attribute macro `spirv_std::spirv_vector` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 7 previous errors
+
+Some errors have detailed explanations: E0277, E0412.
+For more information about an error, try `rustc --explain E0277`.

tests/compiletests/ui/glam/spirv_vector_macro.rs

@@ -0,0 +1,33 @@
+// build-pass
+// only-vulkan1.2
+// compile-flags: -C target-feature=+GroupNonUniform,+GroupNonUniformShuffleRelative,+ext:SPV_KHR_vulkan_memory_model
+// compile-flags: -C llvm-args=--disassemble
+// normalize-stderr-test "OpSource .*\n" -> ""
+// normalize-stderr-test "OpLine .*\n" -> ""
+// normalize-stderr-test "%\d+ = OpString .*\n" -> ""
+
+use spirv_std::arch::subgroup_shuffle_up;
+use spirv_std::glam::Vec3;
+use spirv_std::spirv;
+
+#[spirv_std::spirv_vector]
+#[derive(Copy, Clone, Default)]
+pub struct MyColor {
+    pub r: f32,
+    pub g: f32,
+    pub b: f32,
+}
+
+#[spirv(compute(threads(32)))]
+pub fn main(
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 0)] input: &Vec3,
+    #[spirv(storage_buffer, descriptor_set = 0, binding = 1)] output: &mut MyColor,
+) {
+    let color = MyColor {
+        r: input.x,
+        g: input.y,
+        b: input.z,
+    };
+    // any function that accepts a `VectorOrScalar` would do
+    *output = subgroup_shuffle_up(color, 5);
+}