Vendor things

third-party/vendor/naga/src/valid/compose.rs

@@ -0,0 +1,133 @@
+#[cfg(feature = "validate")]
+use crate::proc::TypeResolution;
+
+use crate::arena::Handle;
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[cfg_attr(test, derive(PartialEq))]
+pub enum ComposeError {
+    #[error("Composing of type {0:?} can't be done")]
+    Type(Handle<crate::Type>),
+    #[error("Composing expects {expected} components but {given} were given")]
+    ComponentCount { given: u32, expected: u32 },
+    #[error("Composing {index}'s component type is not expected")]
+    ComponentType { index: u32 },
+}
+
+#[cfg(feature = "validate")]
+pub fn validate_compose(
+    self_ty_handle: Handle<crate::Type>,
+    gctx: crate::proc::GlobalCtx,
+    component_resolutions: impl ExactSizeIterator<Item = TypeResolution>,
+) -> Result<(), ComposeError> {
+    use crate::TypeInner as Ti;
+
+    match gctx.types[self_ty_handle].inner {
+        // vectors are composed from scalars or other vectors
+        Ti::Vector { size, kind, width } => {
+            let mut total = 0;
+            for (index, comp_res) in component_resolutions.enumerate() {
+                total += match *comp_res.inner_with(gctx.types) {
+                    Ti::Scalar {
+                        kind: comp_kind,
+                        width: comp_width,
+                    } if comp_kind == kind && comp_width == width => 1,
+                    Ti::Vector {
+                        size: comp_size,
+                        kind: comp_kind,
+                        width: comp_width,
+                    } if comp_kind == kind && comp_width == width => comp_size as u32,
+                    ref other => {
+                        log::error!("Vector component[{}] type {:?}", index, other);
+                        return Err(ComposeError::ComponentType {
+                            index: index as u32,
+                        });
+                    }
+                };
+            }
+            if size as u32 != total {
+                return Err(ComposeError::ComponentCount {
+                    expected: size as u32,
+                    given: total,
+                });
+            }
+        }
+        // matrix are composed from column vectors
+        Ti::Matrix {
+            columns,
+            rows,
+            width,
+        } => {
+            let inner = Ti::Vector {
+                size: rows,
+                kind: crate::ScalarKind::Float,
+                width,
+            };
+            if columns as usize != component_resolutions.len() {
+                return Err(ComposeError::ComponentCount {
+                    expected: columns as u32,
+                    given: component_resolutions.len() as u32,
+                });
+            }
+            for (index, comp_res) in component_resolutions.enumerate() {
+                if comp_res.inner_with(gctx.types) != &inner {
+                    log::error!("Matrix component[{}] type {:?}", index, comp_res);
+                    return Err(ComposeError::ComponentType {
+                        index: index as u32,
+                    });
+                }
+            }
+        }
+        Ti::Array {
+            base,
+            size: crate::ArraySize::Constant(count),
+            stride: _,
+        } => {
+            if count.get() as usize != component_resolutions.len() {
+                return Err(ComposeError::ComponentCount {
+                    expected: count.get(),
+                    given: component_resolutions.len() as u32,
+                });
+            }
+            for (index, comp_res) in component_resolutions.enumerate() {
+                let base_inner = &gctx.types[base].inner;
+                let comp_res_inner = comp_res.inner_with(gctx.types);
+                // We don't support arrays of pointers, but it seems best not to
+                // embed that assumption here, so use `TypeInner::equivalent`.
+                if !base_inner.equivalent(comp_res_inner, gctx.types) {
+                    log::error!("Array component[{}] type {:?}", index, comp_res);
+                    return Err(ComposeError::ComponentType {
+                        index: index as u32,
+                    });
+                }
+            }
+        }
+        Ti::Struct { ref members, .. } => {
+            if members.len() != component_resolutions.len() {
+                return Err(ComposeError::ComponentCount {
+                    given: component_resolutions.len() as u32,
+                    expected: members.len() as u32,
+                });
+            }
+            for (index, (member, comp_res)) in members.iter().zip(component_resolutions).enumerate()
+            {
+                let member_inner = &gctx.types[member.ty].inner;
+                let comp_res_inner = comp_res.inner_with(gctx.types);
+                // We don't support pointers in structs, but it seems best not to embed
+                // that assumption here, so use `TypeInner::equivalent`.
+                if !comp_res_inner.equivalent(member_inner, gctx.types) {
+                    log::error!("Struct component[{}] type {:?}", index, comp_res);
+                    return Err(ComposeError::ComponentType {
+                        index: index as u32,
+                    });
+                }
+            }
+        }
+        ref other => {
+            log::error!("Composing of {:?}", other);
+            return Err(ComposeError::Type(self_ty_handle));
+        }
+    }
+
+    Ok(())
+}

third-party/vendor/naga/src/valid/handles.rs

@@ -0,0 +1,712 @@
+//! Implementation of `Validator::validate_module_handles`.
+
+use crate::{
+    arena::{BadHandle, BadRangeError},
+    Handle,
+};
+
+#[cfg(feature = "validate")]
+use crate::{Arena, UniqueArena};
+
+#[cfg(feature = "validate")]
+use super::ValidationError;
+
+#[cfg(feature = "validate")]
+use std::{convert::TryInto, hash::Hash, num::NonZeroU32};
+
+#[cfg(feature = "validate")]
+impl super::Validator {
+    /// Validates that all handles within `module` are:
+    ///
+    /// * Valid, in the sense that they contain indices within each arena structure inside the
+    /// [`crate::Module`] type.
+    /// * No arena contents contain any items that have forward dependencies; that is, the value
+    ///     associated with a handle only may contain references to handles in the same arena that
+    ///     were constructed before it.
+    ///
+    /// By validating the above conditions, we free up subsequent logic to assume that handle
+    /// accesses are infallible.
+    ///
+    /// # Errors
+    ///
+    /// Errors returned by this method are intentionally sparse, for simplicity of implementation.
+    /// It is expected that only buggy frontends or fuzzers should ever emit IR that fails this
+    /// validation pass.
+    pub(super) fn validate_module_handles(module: &crate::Module) -> Result<(), ValidationError> {
+        let &crate::Module {
+            ref constants,
+            ref entry_points,
+            ref functions,
+            ref global_variables,
+            ref types,
+            ref special_types,
+            ref const_expressions,
+        } = module;
+
+        // NOTE: Types being first is important. All other forms of validation depend on this.
+        for (this_handle, ty) in types.iter() {
+            match ty.inner {
+                crate::TypeInner::Scalar { .. }
+                | crate::TypeInner::Vector { .. }
+                | crate::TypeInner::Matrix { .. }
+                | crate::TypeInner::ValuePointer { .. }
+                | crate::TypeInner::Atomic { .. }
+                | crate::TypeInner::Image { .. }
+                | crate::TypeInner::Sampler { .. }
+                | crate::TypeInner::AccelerationStructure
+                | crate::TypeInner::RayQuery => (),
+                crate::TypeInner::Pointer { base, space: _ } => {
+                    this_handle.check_dep(base)?;
+                }
+                crate::TypeInner::Array { base, .. }
+                | crate::TypeInner::BindingArray { base, .. } => {
+                    this_handle.check_dep(base)?;
+                }
+                crate::TypeInner::Struct {
+                    ref members,
+                    span: _,
+                } => {
+                    this_handle.check_dep_iter(members.iter().map(|m| m.ty))?;
+                }
+            }
+        }
+
+        for handle_and_expr in const_expressions.iter() {
+            Self::validate_const_expression_handles(handle_and_expr, constants, types)?;
+        }
+
+        let validate_type = |handle| Self::validate_type_handle(handle, types);
+        let validate_const_expr =
+            |handle| Self::validate_expression_handle(handle, const_expressions);
+
+        for (_handle, constant) in constants.iter() {
+            let &crate::Constant {
+                name: _,
+                r#override: _,
+                ty,
+                init,
+            } = constant;
+            validate_type(ty)?;
+            validate_const_expr(init)?;
+        }
+
+        for (_handle, global_variable) in global_variables.iter() {
+            let &crate::GlobalVariable {
+                name: _,
+                space: _,
+                binding: _,
+                ty,
+                init,
+            } = global_variable;
+            validate_type(ty)?;
+            if let Some(init_expr) = init {
+                validate_const_expr(init_expr)?;
+            }
+        }
+
+        let validate_function = |function_handle, function: &_| -> Result<_, InvalidHandleError> {
+            let &crate::Function {
+                name: _,
+                ref arguments,
+                ref result,
+                ref local_variables,
+                ref expressions,
+                ref named_expressions,
+                ref body,
+            } = function;
+
+            for arg in arguments.iter() {
+                let &crate::FunctionArgument {
+                    name: _,
+                    ty,
+                    binding: _,
+                } = arg;
+                validate_type(ty)?;
+            }
+
+            if let &Some(crate::FunctionResult { ty, binding: _ }) = result {
+                validate_type(ty)?;
+            }
+
+            for (_handle, local_variable) in local_variables.iter() {
+                let &crate::LocalVariable { name: _, ty, init } = local_variable;
+                validate_type(ty)?;
+                if let Some(init_constant) = init {
+                    validate_const_expr(init_constant)?;
+                }
+            }
+
+            for handle in named_expressions.keys().copied() {
+                Self::validate_expression_handle(handle, expressions)?;
+            }
+
+            for handle_and_expr in expressions.iter() {
+                Self::validate_expression_handles(
+                    handle_and_expr,
+                    constants,
+                    const_expressions,
+                    types,
+                    local_variables,
+                    global_variables,
+                    functions,
+                    function_handle,
+                )?;
+            }
+
+            Self::validate_block_handles(body, expressions, functions)?;
+
+            Ok(())
+        };
+
+        for entry_point in entry_points.iter() {
+            validate_function(None, &entry_point.function)?;
+        }
+
+        for (function_handle, function) in functions.iter() {
+            validate_function(Some(function_handle), function)?;
+        }
+
+        if let Some(ty) = special_types.ray_desc {
+            validate_type(ty)?;
+        }
+        if let Some(ty) = special_types.ray_intersection {
+            validate_type(ty)?;
+        }
+
+        Ok(())
+    }
+
+    fn validate_type_handle(
+        handle: Handle<crate::Type>,
+        types: &UniqueArena<crate::Type>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for_uniq(types).map(|_| ())
+    }
+
+    fn validate_constant_handle(
+        handle: Handle<crate::Constant>,
+        constants: &Arena<crate::Constant>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for(constants).map(|_| ())
+    }
+
+    fn validate_expression_handle(
+        handle: Handle<crate::Expression>,
+        expressions: &Arena<crate::Expression>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for(expressions).map(|_| ())
+    }
+
+    fn validate_function_handle(
+        handle: Handle<crate::Function>,
+        functions: &Arena<crate::Function>,
+    ) -> Result<(), InvalidHandleError> {
+        handle.check_valid_for(functions).map(|_| ())
+    }
+
+    fn validate_const_expression_handles(
+        (handle, expression): (Handle<crate::Expression>, &crate::Expression),
+        constants: &Arena<crate::Constant>,
+        types: &UniqueArena<crate::Type>,
+    ) -> Result<(), InvalidHandleError> {
+        let validate_constant = |handle| Self::validate_constant_handle(handle, constants);
+        let validate_type = |handle| Self::validate_type_handle(handle, types);
+
+        match *expression {
+            crate::Expression::Literal(_) => {}
+            crate::Expression::Constant(constant) => {
+                validate_constant(constant)?;
+                handle.check_dep(constants[constant].init)?;
+            }
+            crate::Expression::ZeroValue(ty) => {
+                validate_type(ty)?;
+            }
+            crate::Expression::Compose { ty, ref components } => {
+                validate_type(ty)?;
+                handle.check_dep_iter(components.iter().copied())?;
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn validate_expression_handles(
+        (handle, expression): (Handle<crate::Expression>, &crate::Expression),
+        constants: &Arena<crate::Constant>,
+        const_expressions: &Arena<crate::Expression>,
+        types: &UniqueArena<crate::Type>,
+        local_variables: &Arena<crate::LocalVariable>,
+        global_variables: &Arena<crate::GlobalVariable>,
+        functions: &Arena<crate::Function>,
+        // The handle of the current function or `None` if it's an entry point
+        current_function: Option<Handle<crate::Function>>,
+    ) -> Result<(), InvalidHandleError> {
+        let validate_constant = |handle| Self::validate_constant_handle(handle, constants);
+        let validate_const_expr =
+            |handle| Self::validate_expression_handle(handle, const_expressions);
+        let validate_type = |handle| Self::validate_type_handle(handle, types);
+
+        match *expression {
+            crate::Expression::Access { base, index } => {
+                handle.check_dep(base)?.check_dep(index)?;
+            }
+            crate::Expression::AccessIndex { base, .. } => {
+                handle.check_dep(base)?;
+            }
+            crate::Expression::Splat { value, .. } => {
+                handle.check_dep(value)?;
+            }
+            crate::Expression::Swizzle { vector, .. } => {
+                handle.check_dep(vector)?;
+            }
+            crate::Expression::Literal(_) => {}
+            crate::Expression::Constant(constant) => {
+                validate_constant(constant)?;
+            }
+            crate::Expression::ZeroValue(ty) => {
+                validate_type(ty)?;
+            }
+            crate::Expression::Compose { ty, ref components } => {
+                validate_type(ty)?;
+                handle.check_dep_iter(components.iter().copied())?;
+            }
+            crate::Expression::FunctionArgument(_arg_idx) => (),
+            crate::Expression::GlobalVariable(global_variable) => {
+                global_variable.check_valid_for(global_variables)?;
+            }
+            crate::Expression::LocalVariable(local_variable) => {
+                local_variable.check_valid_for(local_variables)?;
+            }
+            crate::Expression::Load { pointer } => {
+                handle.check_dep(pointer)?;
+            }
+            crate::Expression::ImageSample {
+                image,
+                sampler,
+                gather: _,
+                coordinate,
+                array_index,
+                offset,
+                level,
+                depth_ref,
+            } => {
+                if let Some(offset) = offset {
+                    validate_const_expr(offset)?;
+                }
+
+                handle
+                    .check_dep(image)?
+                    .check_dep(sampler)?
+                    .check_dep(coordinate)?
+                    .check_dep_opt(array_index)?;
+
+                match level {
+                    crate::SampleLevel::Auto | crate::SampleLevel::Zero => (),
+                    crate::SampleLevel::Exact(expr) => {
+                        handle.check_dep(expr)?;
+                    }
+                    crate::SampleLevel::Bias(expr) => {
+                        handle.check_dep(expr)?;
+                    }
+                    crate::SampleLevel::Gradient { x, y } => {
+                        handle.check_dep(x)?.check_dep(y)?;
+                    }
+                };
+
+                handle.check_dep_opt(depth_ref)?;
+            }
+            crate::Expression::ImageLoad {
+                image,
+                coordinate,
+                array_index,
+                sample,
+                level,
+            } => {
+                handle
+                    .check_dep(image)?
+                    .check_dep(coordinate)?
+                    .check_dep_opt(array_index)?
+                    .check_dep_opt(sample)?
+                    .check_dep_opt(level)?;
+            }
+            crate::Expression::ImageQuery { image, query } => {
+                handle.check_dep(image)?;
+                match query {
+                    crate::ImageQuery::Size { level } => {
+                        handle.check_dep_opt(level)?;
+                    }
+                    crate::ImageQuery::NumLevels
+                    | crate::ImageQuery::NumLayers
+                    | crate::ImageQuery::NumSamples => (),
+                };
+            }
+            crate::Expression::Unary {
+                op: _,
+                expr: operand,
+            } => {
+                handle.check_dep(operand)?;
+            }
+            crate::Expression::Binary { op: _, left, right } => {
+                handle.check_dep(left)?.check_dep(right)?;
+            }
+            crate::Expression::Select {
+                condition,
+                accept,
+                reject,
+            } => {
+                handle
+                    .check_dep(condition)?
+                    .check_dep(accept)?
+                    .check_dep(reject)?;
+            }
+            crate::Expression::Derivative { expr: argument, .. } => {
+                handle.check_dep(argument)?;
+            }
+            crate::Expression::Relational { fun: _, argument } => {
+                handle.check_dep(argument)?;
+            }
+            crate::Expression::Math {
+                fun: _,
+                arg,
+                arg1,
+                arg2,
+                arg3,
+            } => {
+                handle
+                    .check_dep(arg)?
+                    .check_dep_opt(arg1)?
+                    .check_dep_opt(arg2)?
+                    .check_dep_opt(arg3)?;
+            }
+            crate::Expression::As {
+                expr: input,
+                kind: _,
+                convert: _,
+            } => {
+                handle.check_dep(input)?;
+            }
+            crate::Expression::CallResult(function) => {
+                Self::validate_function_handle(function, functions)?;
+                if let Some(handle) = current_function {
+                    handle.check_dep(function)?;
+                }
+            }
+            crate::Expression::AtomicResult { .. }
+            | crate::Expression::RayQueryProceedResult
+            | crate::Expression::WorkGroupUniformLoadResult { .. } => (),
+            crate::Expression::ArrayLength(array) => {
+                handle.check_dep(array)?;
+            }
+            crate::Expression::RayQueryGetIntersection {
+                query,
+                committed: _,
+            } => {
+                handle.check_dep(query)?;
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_block_handles(
+        block: &crate::Block,
+        expressions: &Arena<crate::Expression>,
+        functions: &Arena<crate::Function>,
+    ) -> Result<(), InvalidHandleError> {
+        let validate_block = |block| Self::validate_block_handles(block, expressions, functions);
+        let validate_expr = |handle| Self::validate_expression_handle(handle, expressions);
+        let validate_expr_opt = |handle_opt| {
+            if let Some(handle) = handle_opt {
+                validate_expr(handle)?;
+            }
+            Ok(())
+        };
+
+        block.iter().try_for_each(|stmt| match *stmt {
+            crate::Statement::Emit(ref expr_range) => {
+                expr_range.check_valid_for(expressions)?;
+                Ok(())
+            }
+            crate::Statement::Block(ref block) => {
+                validate_block(block)?;
+                Ok(())
+            }
+            crate::Statement::If {
+                condition,
+                ref accept,
+                ref reject,
+            } => {
+                validate_expr(condition)?;
+                validate_block(accept)?;
+                validate_block(reject)?;
+                Ok(())
+            }
+            crate::Statement::Switch {
+                selector,
+                ref cases,
+            } => {
+                validate_expr(selector)?;
+                for &crate::SwitchCase {
+                    value: _,
+                    ref body,
+                    fall_through: _,
+                } in cases
+                {
+                    validate_block(body)?;
+                }
+                Ok(())
+            }
+            crate::Statement::Loop {
+                ref body,
+                ref continuing,
+                break_if,
+            } => {
+                validate_block(body)?;
+                validate_block(continuing)?;
+                validate_expr_opt(break_if)?;
+                Ok(())
+            }
+            crate::Statement::Return { value } => validate_expr_opt(value),
+            crate::Statement::Store { pointer, value } => {
+                validate_expr(pointer)?;
+                validate_expr(value)?;
+                Ok(())
+            }
+            crate::Statement::ImageStore {
+                image,
+                coordinate,
+                array_index,
+                value,
+            } => {
+                validate_expr(image)?;
+                validate_expr(coordinate)?;
+                validate_expr_opt(array_index)?;
+                validate_expr(value)?;
+                Ok(())
+            }
+            crate::Statement::Atomic {
+                pointer,
+                fun,
+                value,
+                result,
+            } => {
+                validate_expr(pointer)?;
+                match fun {
+                    crate::AtomicFunction::Add
+                    | crate::AtomicFunction::Subtract
+                    | crate::AtomicFunction::And
+                    | crate::AtomicFunction::ExclusiveOr
+                    | crate::AtomicFunction::InclusiveOr
+                    | crate::AtomicFunction::Min
+                    | crate::AtomicFunction::Max => (),
+                    crate::AtomicFunction::Exchange { compare } => validate_expr_opt(compare)?,
+                };
+                validate_expr(value)?;
+                validate_expr(result)?;
+                Ok(())
+            }
+            crate::Statement::WorkGroupUniformLoad { pointer, result } => {
+                validate_expr(pointer)?;
+                validate_expr(result)?;
+                Ok(())
+            }
+            crate::Statement::Call {
+                function,
+                ref arguments,
+                result,
+            } => {
+                Self::validate_function_handle(function, functions)?;
+                for arg in arguments.iter().copied() {
+                    validate_expr(arg)?;
+                }
+                validate_expr_opt(result)?;
+                Ok(())
+            }
+            crate::Statement::RayQuery { query, ref fun } => {
+                validate_expr(query)?;
+                match *fun {
+                    crate::RayQueryFunction::Initialize {
+                        acceleration_structure,
+                        descriptor,
+                    } => {
+                        validate_expr(acceleration_structure)?;
+                        validate_expr(descriptor)?;
+                    }
+                    crate::RayQueryFunction::Proceed { result } => {
+                        validate_expr(result)?;
+                    }
+                    crate::RayQueryFunction::Terminate => {}
+                }
+                Ok(())
+            }
+            crate::Statement::Break
+            | crate::Statement::Continue
+            | crate::Statement::Kill
+            | crate::Statement::Barrier(_) => Ok(()),
+        })
+    }
+}
+
+#[cfg(feature = "validate")]
+impl From<BadHandle> for ValidationError {
+    fn from(source: BadHandle) -> Self {
+        Self::InvalidHandle(source.into())
+    }
+}
+
+#[cfg(feature = "validate")]
+impl From<FwdDepError> for ValidationError {
+    fn from(source: FwdDepError) -> Self {
+        Self::InvalidHandle(source.into())
+    }
+}
+
+#[cfg(feature = "validate")]
+impl From<BadRangeError> for ValidationError {
+    fn from(source: BadRangeError) -> Self {
+        Self::InvalidHandle(source.into())
+    }
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum InvalidHandleError {
+    #[error(transparent)]
+    BadHandle(#[from] BadHandle),
+    #[error(transparent)]
+    ForwardDependency(#[from] FwdDepError),
+    #[error(transparent)]
+    BadRange(#[from] BadRangeError),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+#[error(
+    "{subject:?} of kind {subject_kind:?} depends on {depends_on:?} of kind {depends_on_kind}, \
+    which has not been processed yet"
+)]
+pub struct FwdDepError {
+    // This error is used for many `Handle` types, but there's no point in making this generic, so
+    // we just flatten them all to `Handle<()>` here.
+    subject: Handle<()>,
+    subject_kind: &'static str,
+    depends_on: Handle<()>,
+    depends_on_kind: &'static str,
+}
+
+#[cfg(feature = "validate")]
+impl<T> Handle<T> {
+    /// Check that `self` is valid within `arena` using [`Arena::check_contains_handle`].
+    pub(self) fn check_valid_for(self, arena: &Arena<T>) -> Result<(), InvalidHandleError> {
+        arena.check_contains_handle(self)?;
+        Ok(())
+    }
+
+    /// Check that `self` is valid within `arena` using [`UniqueArena::check_contains_handle`].
+    pub(self) fn check_valid_for_uniq(
+        self,
+        arena: &UniqueArena<T>,
+    ) -> Result<(), InvalidHandleError>
+    where
+        T: Eq + Hash,
+    {
+        arena.check_contains_handle(self)?;
+        Ok(())
+    }
+
+    /// Check that `depends_on` was constructed before `self` by comparing handle indices.
+    ///
+    /// If `self` is a valid handle (i.e., it has been validated using [`Self::check_valid_for`])
+    /// and this function returns [`Ok`], then it may be assumed that `depends_on` is also valid.
+    /// In [`naga`](crate)'s current arena-based implementation, this is useful for validating
+    /// recursive definitions of arena-based values in linear time.
+    ///
+    /// # Errors
+    ///
+    /// If `depends_on`'s handle is from the same [`Arena`] as `self'`s, but not constructed earlier
+    /// than `self`'s, this function returns an error.
+    pub(self) fn check_dep(self, depends_on: Self) -> Result<Self, FwdDepError> {
+        if depends_on < self {
+            Ok(self)
+        } else {
+            let erase_handle_type = |handle: Handle<_>| {
+                Handle::new(NonZeroU32::new((handle.index() + 1).try_into().unwrap()).unwrap())
+            };
+            Err(FwdDepError {
+                subject: erase_handle_type(self),
+                subject_kind: std::any::type_name::<T>(),
+                depends_on: erase_handle_type(depends_on),
+                depends_on_kind: std::any::type_name::<T>(),
+            })
+        }
+    }
+
+    /// Like [`Self::check_dep`], except for [`Option`]al handle values.
+    pub(self) fn check_dep_opt(self, depends_on: Option<Self>) -> Result<Self, FwdDepError> {
+        self.check_dep_iter(depends_on.into_iter())
+    }
+
+    /// Like [`Self::check_dep`], except for [`Iterator`]s over handle values.
+    pub(self) fn check_dep_iter(
+        self,
+        depends_on: impl Iterator<Item = Self>,
+    ) -> Result<Self, FwdDepError> {
+        for handle in depends_on {
+            self.check_dep(handle)?;
+        }
+        Ok(self)
+    }
+}
+
+#[cfg(feature = "validate")]
+impl<T> crate::arena::Range<T> {
+    pub(self) fn check_valid_for(&self, arena: &Arena<T>) -> Result<(), BadRangeError> {
+        arena.check_contains_range(self)
+    }
+}
+
+#[test]
+#[cfg(feature = "validate")]
+fn constant_deps() {
+    use crate::{Constant, Expression, Literal, Span, Type, TypeInner};
+
+    let nowhere = Span::default();
+
+    let mut types = UniqueArena::new();
+    let mut const_exprs = Arena::new();
+    let mut fun_exprs = Arena::new();
+    let mut constants = Arena::new();
+
+    let i32_handle = types.insert(
+        Type {
+            name: None,
+            inner: TypeInner::Scalar {
+                kind: crate::ScalarKind::Sint,
+                width: 4,
+            },
+        },
+        nowhere,
+    );
+
+    // Construct a self-referential constant by misusing a handle to
+    // fun_exprs as a constant initializer.
+    let fun_expr = fun_exprs.append(Expression::Literal(Literal::I32(42)), nowhere);
+    let self_referential_const = constants.append(
+        Constant {
+            name: None,
+            r#override: crate::Override::None,
+            ty: i32_handle,
+            init: fun_expr,
+        },
+        nowhere,
+    );
+    let _self_referential_expr =
+        const_exprs.append(Expression::Constant(self_referential_const), nowhere);
+
+    for handle_and_expr in const_exprs.iter() {
+        assert!(super::Validator::validate_const_expression_handles(
+            handle_and_expr,
+            &constants,
+            &types,
+        )
+        .is_err());
+    }
+}

third-party/vendor/naga/src/valid/interface.rs

@@ -0,0 +1,686 @@
+use super::{
+    analyzer::{FunctionInfo, GlobalUse},
+    Capabilities, Disalignment, FunctionError, ModuleInfo,
+};
+use crate::arena::{Handle, UniqueArena};
+
+use crate::span::{AddSpan as _, MapErrWithSpan as _, SpanProvider as _, WithSpan};
+use bit_set::BitSet;
+
+#[cfg(feature = "validate")]
+const MAX_WORKGROUP_SIZE: u32 = 0x4000;
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum GlobalVariableError {
+    #[error("Usage isn't compatible with address space {0:?}")]
+    InvalidUsage(crate::AddressSpace),
+    #[error("Type isn't compatible with address space {0:?}")]
+    InvalidType(crate::AddressSpace),
+    #[error("Type flags {seen:?} do not meet the required {required:?}")]
+    MissingTypeFlags {
+        required: super::TypeFlags,
+        seen: super::TypeFlags,
+    },
+    #[error("Capability {0:?} is not supported")]
+    UnsupportedCapability(Capabilities),
+    #[error("Binding decoration is missing or not applicable")]
+    InvalidBinding,
+    #[error("Alignment requirements for address space {0:?} are not met by {1:?}")]
+    Alignment(
+        crate::AddressSpace,
+        Handle<crate::Type>,
+        #[source] Disalignment,
+    ),
+    #[error("Initializer doesn't match the variable type")]
+    InitializerType,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum VaryingError {
+    #[error("The type {0:?} does not match the varying")]
+    InvalidType(Handle<crate::Type>),
+    #[error("The type {0:?} cannot be used for user-defined entry point inputs or outputs")]
+    NotIOShareableType(Handle<crate::Type>),
+    #[error("Interpolation is not valid")]
+    InvalidInterpolation,
+    #[error("Interpolation must be specified on vertex shader outputs and fragment shader inputs")]
+    MissingInterpolation,
+    #[error("Built-in {0:?} is not available at this stage")]
+    InvalidBuiltInStage(crate::BuiltIn),
+    #[error("Built-in type for {0:?} is invalid")]
+    InvalidBuiltInType(crate::BuiltIn),
+    #[error("Entry point arguments and return values must all have bindings")]
+    MissingBinding,
+    #[error("Struct member {0} is missing a binding")]
+    MemberMissingBinding(u32),
+    #[error("Multiple bindings at location {location} are present")]
+    BindingCollision { location: u32 },
+    #[error("Built-in {0:?} is present more than once")]
+    DuplicateBuiltIn(crate::BuiltIn),
+    #[error("Capability {0:?} is not supported")]
+    UnsupportedCapability(Capabilities),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum EntryPointError {
+    #[error("Multiple conflicting entry points")]
+    Conflict,
+    #[error("Vertex shaders must return a `@builtin(position)` output value")]
+    MissingVertexOutputPosition,
+    #[error("Early depth test is not applicable")]
+    UnexpectedEarlyDepthTest,
+    #[error("Workgroup size is not applicable")]
+    UnexpectedWorkgroupSize,
+    #[error("Workgroup size is out of range")]
+    OutOfRangeWorkgroupSize,
+    #[error("Uses operations forbidden at this stage")]
+    ForbiddenStageOperations,
+    #[error("Global variable {0:?} is used incorrectly as {1:?}")]
+    InvalidGlobalUsage(Handle<crate::GlobalVariable>, GlobalUse),
+    #[error("Bindings for {0:?} conflict with other resource")]
+    BindingCollision(Handle<crate::GlobalVariable>),
+    #[error("Argument {0} varying error")]
+    Argument(u32, #[source] VaryingError),
+    #[error(transparent)]
+    Result(#[from] VaryingError),
+    #[error("Location {location} interpolation of an integer has to be flat")]
+    InvalidIntegerInterpolation { location: u32 },
+    #[error(transparent)]
+    Function(#[from] FunctionError),
+}
+
+#[cfg(feature = "validate")]
+fn storage_usage(access: crate::StorageAccess) -> GlobalUse {
+    let mut storage_usage = GlobalUse::QUERY;
+    if access.contains(crate::StorageAccess::LOAD) {
+        storage_usage |= GlobalUse::READ;
+    }
+    if access.contains(crate::StorageAccess::STORE) {
+        storage_usage |= GlobalUse::WRITE;
+    }
+    storage_usage
+}
+
+struct VaryingContext<'a> {
+    stage: crate::ShaderStage,
+    output: bool,
+    types: &'a UniqueArena<crate::Type>,
+    type_info: &'a Vec<super::r#type::TypeInfo>,
+    location_mask: &'a mut BitSet,
+    built_ins: &'a mut crate::FastHashSet<crate::BuiltIn>,
+    capabilities: Capabilities,
+
+    #[cfg(feature = "validate")]
+    flags: super::ValidationFlags,
+}
+
+impl VaryingContext<'_> {
+    fn validate_impl(
+        &mut self,
+        ty: Handle<crate::Type>,
+        binding: &crate::Binding,
+    ) -> Result<(), VaryingError> {
+        use crate::{
+            BuiltIn as Bi, ScalarKind as Sk, ShaderStage as St, TypeInner as Ti, VectorSize as Vs,
+        };
+
+        let ty_inner = &self.types[ty].inner;
+        match *binding {
+            crate::Binding::BuiltIn(built_in) => {
+                // Ignore the `invariant` field for the sake of duplicate checks,
+                // but use the original in error messages.
+                let canonical = if let crate::BuiltIn::Position { .. } = built_in {
+                    crate::BuiltIn::Position { invariant: false }
+                } else {
+                    built_in
+                };
+
+                if self.built_ins.contains(&canonical) {
+                    return Err(VaryingError::DuplicateBuiltIn(built_in));
+                }
+                self.built_ins.insert(canonical);
+
+                let required = match built_in {
+                    Bi::ClipDistance => Capabilities::CLIP_DISTANCE,
+                    Bi::CullDistance => Capabilities::CULL_DISTANCE,
+                    Bi::PrimitiveIndex => Capabilities::PRIMITIVE_INDEX,
+                    Bi::ViewIndex => Capabilities::MULTIVIEW,
+                    Bi::SampleIndex => Capabilities::MULTISAMPLED_SHADING,
+                    _ => Capabilities::empty(),
+                };
+                if !self.capabilities.contains(required) {
+                    return Err(VaryingError::UnsupportedCapability(required));
+                }
+
+                let width = 4;
+                let (visible, type_good) = match built_in {
+                    Bi::BaseInstance | Bi::BaseVertex | Bi::InstanceIndex | Bi::VertexIndex => (
+                        self.stage == St::Vertex && !self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Uint,
+                                width,
+                            },
+                    ),
+                    Bi::ClipDistance | Bi::CullDistance => (
+                        self.stage == St::Vertex && self.output,
+                        match *ty_inner {
+                            Ti::Array { base, .. } => {
+                                self.types[base].inner
+                                    == Ti::Scalar {
+                                        kind: Sk::Float,
+                                        width,
+                                    }
+                            }
+                            _ => false,
+                        },
+                    ),
+                    Bi::PointSize => (
+                        self.stage == St::Vertex && self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Float,
+                                width,
+                            },
+                    ),
+                    Bi::PointCoord => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Bi,
+                                kind: Sk::Float,
+                                width,
+                            },
+                    ),
+                    Bi::Position { .. } => (
+                        match self.stage {
+                            St::Vertex => self.output,
+                            St::Fragment => !self.output,
+                            St::Compute => false,
+                        },
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Quad,
+                                kind: Sk::Float,
+                                width,
+                            },
+                    ),
+                    Bi::ViewIndex => (
+                        match self.stage {
+                            St::Vertex | St::Fragment => !self.output,
+                            St::Compute => false,
+                        },
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Sint,
+                                width,
+                            },
+                    ),
+                    Bi::FragDepth => (
+                        self.stage == St::Fragment && self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Float,
+                                width,
+                            },
+                    ),
+                    Bi::FrontFacing => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Bool,
+                                width: crate::BOOL_WIDTH,
+                            },
+                    ),
+                    Bi::PrimitiveIndex => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Uint,
+                                width,
+                            },
+                    ),
+                    Bi::SampleIndex => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Uint,
+                                width,
+                            },
+                    ),
+                    Bi::SampleMask => (
+                        self.stage == St::Fragment,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Uint,
+                                width,
+                            },
+                    ),
+                    Bi::LocalInvocationIndex => (
+                        self.stage == St::Compute && !self.output,
+                        *ty_inner
+                            == Ti::Scalar {
+                                kind: Sk::Uint,
+                                width,
+                            },
+                    ),
+                    Bi::GlobalInvocationId
+                    | Bi::LocalInvocationId
+                    | Bi::WorkGroupId
+                    | Bi::WorkGroupSize
+                    | Bi::NumWorkGroups => (
+                        self.stage == St::Compute && !self.output,
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Tri,
+                                kind: Sk::Uint,
+                                width,
+                            },
+                    ),
+                };
+
+                if !visible {
+                    return Err(VaryingError::InvalidBuiltInStage(built_in));
+                }
+                if !type_good {
+                    log::warn!("Wrong builtin type: {:?}", ty_inner);
+                    return Err(VaryingError::InvalidBuiltInType(built_in));
+                }
+            }
+            crate::Binding::Location {
+                location,
+                interpolation,
+                sampling,
+            } => {
+                // Only IO-shareable types may be stored in locations.
+                if !self.type_info[ty.index()]
+                    .flags
+                    .contains(super::TypeFlags::IO_SHAREABLE)
+                {
+                    return Err(VaryingError::NotIOShareableType(ty));
+                }
+                if !self.location_mask.insert(location as usize) {
+                    #[cfg(feature = "validate")]
+                    if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                        return Err(VaryingError::BindingCollision { location });
+                    }
+                }
+
+                let needs_interpolation = match self.stage {
+                    crate::ShaderStage::Vertex => self.output,
+                    crate::ShaderStage::Fragment => !self.output,
+                    crate::ShaderStage::Compute => false,
+                };
+
+                // It doesn't make sense to specify a sampling when `interpolation` is `Flat`, but
+                // SPIR-V and GLSL both explicitly tolerate such combinations of decorators /
+                // qualifiers, so we won't complain about that here.
+                let _ = sampling;
+
+                let required = match sampling {
+                    Some(crate::Sampling::Sample) => Capabilities::MULTISAMPLED_SHADING,
+                    _ => Capabilities::empty(),
+                };
+                if !self.capabilities.contains(required) {
+                    return Err(VaryingError::UnsupportedCapability(required));
+                }
+
+                match ty_inner.scalar_kind() {
+                    Some(crate::ScalarKind::Float) => {
+                        if needs_interpolation && interpolation.is_none() {
+                            return Err(VaryingError::MissingInterpolation);
+                        }
+                    }
+                    Some(_) => {
+                        if needs_interpolation && interpolation != Some(crate::Interpolation::Flat)
+                        {
+                            return Err(VaryingError::InvalidInterpolation);
+                        }
+                    }
+                    None => return Err(VaryingError::InvalidType(ty)),
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn validate(
+        &mut self,
+        ty: Handle<crate::Type>,
+        binding: Option<&crate::Binding>,
+    ) -> Result<(), WithSpan<VaryingError>> {
+        let span_context = self.types.get_span_context(ty);
+        match binding {
+            Some(binding) => self
+                .validate_impl(ty, binding)
+                .map_err(|e| e.with_span_context(span_context)),
+            None => {
+                match self.types[ty].inner {
+                    crate::TypeInner::Struct { ref members, .. } => {
+                        for (index, member) in members.iter().enumerate() {
+                            let span_context = self.types.get_span_context(ty);
+                            match member.binding {
+                                None => {
+                                    #[cfg(feature = "validate")]
+                                    if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                                        return Err(VaryingError::MemberMissingBinding(
+                                            index as u32,
+                                        )
+                                        .with_span_context(span_context));
+                                    }
+                                    #[cfg(not(feature = "validate"))]
+                                    let _ = index;
+                                }
+                                Some(ref binding) => self
+                                    .validate_impl(member.ty, binding)
+                                    .map_err(|e| e.with_span_context(span_context))?,
+                            }
+                        }
+                    }
+                    _ =>
+                    {
+                        #[cfg(feature = "validate")]
+                        if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                            return Err(VaryingError::MissingBinding.with_span());
+                        }
+                    }
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl super::Validator {
+    #[cfg(feature = "validate")]
+    pub(super) fn validate_global_var(
+        &self,
+        var: &crate::GlobalVariable,
+        gctx: crate::proc::GlobalCtx,
+        mod_info: &ModuleInfo,
+    ) -> Result<(), GlobalVariableError> {
+        use super::TypeFlags;
+
+        log::debug!("var {:?}", var);
+        let inner_ty = match gctx.types[var.ty].inner {
+            // A binding array is (mostly) supposed to behave the same as a
+            // series of individually bound resources, so we can (mostly)
+            // validate a `binding_array<T>` as if it were just a plain `T`.
+            crate::TypeInner::BindingArray { base, .. } => base,
+            _ => var.ty,
+        };
+        let type_info = &self.types[inner_ty.index()];
+
+        let (required_type_flags, is_resource) = match var.space {
+            crate::AddressSpace::Function => {
+                return Err(GlobalVariableError::InvalidUsage(var.space))
+            }
+            crate::AddressSpace::Storage { .. } => {
+                if let Err((ty_handle, disalignment)) = type_info.storage_layout {
+                    if self.flags.contains(super::ValidationFlags::STRUCT_LAYOUTS) {
+                        return Err(GlobalVariableError::Alignment(
+                            var.space,
+                            ty_handle,
+                            disalignment,
+                        ));
+                    }
+                }
+                (TypeFlags::DATA | TypeFlags::HOST_SHAREABLE, true)
+            }
+            crate::AddressSpace::Uniform => {
+                if let Err((ty_handle, disalignment)) = type_info.uniform_layout {
+                    if self.flags.contains(super::ValidationFlags::STRUCT_LAYOUTS) {
+                        return Err(GlobalVariableError::Alignment(
+                            var.space,
+                            ty_handle,
+                            disalignment,
+                        ));
+                    }
+                }
+                (
+                    TypeFlags::DATA
+                        | TypeFlags::COPY
+                        | TypeFlags::SIZED
+                        | TypeFlags::HOST_SHAREABLE,
+                    true,
+                )
+            }
+            crate::AddressSpace::Handle => {
+                match gctx.types[inner_ty].inner {
+                    crate::TypeInner::Image { class, .. } => match class {
+                        crate::ImageClass::Storage {
+                            format:
+                                crate::StorageFormat::R16Unorm
+                                | crate::StorageFormat::R16Snorm
+                                | crate::StorageFormat::Rg16Unorm
+                                | crate::StorageFormat::Rg16Snorm
+                                | crate::StorageFormat::Rgba16Unorm
+                                | crate::StorageFormat::Rgba16Snorm,
+                            ..
+                        } => {
+                            if !self
+                                .capabilities
+                                .contains(Capabilities::STORAGE_TEXTURE_16BIT_NORM_FORMATS)
+                            {
+                                return Err(GlobalVariableError::UnsupportedCapability(
+                                    Capabilities::STORAGE_TEXTURE_16BIT_NORM_FORMATS,
+                                ));
+                            }
+                        }
+                        _ => {}
+                    },
+                    crate::TypeInner::Sampler { .. }
+                    | crate::TypeInner::AccelerationStructure
+                    | crate::TypeInner::RayQuery => {}
+                    _ => {
+                        return Err(GlobalVariableError::InvalidType(var.space));
+                    }
+                }
+
+                (TypeFlags::empty(), true)
+            }
+            crate::AddressSpace::Private | crate::AddressSpace::WorkGroup => {
+                (TypeFlags::DATA | TypeFlags::SIZED, false)
+            }
+            crate::AddressSpace::PushConstant => {
+                if !self.capabilities.contains(Capabilities::PUSH_CONSTANT) {
+                    return Err(GlobalVariableError::UnsupportedCapability(
+                        Capabilities::PUSH_CONSTANT,
+                    ));
+                }
+                (
+                    TypeFlags::DATA
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::SIZED,
+                    false,
+                )
+            }
+        };
+
+        if !type_info.flags.contains(required_type_flags) {
+            return Err(GlobalVariableError::MissingTypeFlags {
+                seen: type_info.flags,
+                required: required_type_flags,
+            });
+        }
+
+        if is_resource != var.binding.is_some() {
+            if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                return Err(GlobalVariableError::InvalidBinding);
+            }
+        }
+
+        if let Some(init) = var.init {
+            let decl_ty = &gctx.types[var.ty].inner;
+            let init_ty = mod_info[init].inner_with(gctx.types);
+            if !decl_ty.equivalent(init_ty, gctx.types) {
+                return Err(GlobalVariableError::InitializerType);
+            }
+        }
+
+        Ok(())
+    }
+
+    pub(super) fn validate_entry_point(
+        &mut self,
+        ep: &crate::EntryPoint,
+        module: &crate::Module,
+        mod_info: &ModuleInfo,
+    ) -> Result<FunctionInfo, WithSpan<EntryPointError>> {
+        #[cfg(feature = "validate")]
+        if ep.early_depth_test.is_some() {
+            let required = Capabilities::EARLY_DEPTH_TEST;
+            if !self.capabilities.contains(required) {
+                return Err(
+                    EntryPointError::Result(VaryingError::UnsupportedCapability(required))
+                        .with_span(),
+                );
+            }
+
+            if ep.stage != crate::ShaderStage::Fragment {
+                return Err(EntryPointError::UnexpectedEarlyDepthTest.with_span());
+            }
+        }
+
+        #[cfg(feature = "validate")]
+        if ep.stage == crate::ShaderStage::Compute {
+            if ep
+                .workgroup_size
+                .iter()
+                .any(|&s| s == 0 || s > MAX_WORKGROUP_SIZE)
+            {
+                return Err(EntryPointError::OutOfRangeWorkgroupSize.with_span());
+            }
+        } else if ep.workgroup_size != [0; 3] {
+            return Err(EntryPointError::UnexpectedWorkgroupSize.with_span());
+        }
+
+        let info = self
+            .validate_function(&ep.function, module, mod_info, true)
+            .map_err(WithSpan::into_other)?;
+
+        #[cfg(feature = "validate")]
+        {
+            use super::ShaderStages;
+
+            let stage_bit = match ep.stage {
+                crate::ShaderStage::Vertex => ShaderStages::VERTEX,
+                crate::ShaderStage::Fragment => ShaderStages::FRAGMENT,
+                crate::ShaderStage::Compute => ShaderStages::COMPUTE,
+            };
+
+            if !info.available_stages.contains(stage_bit) {
+                return Err(EntryPointError::ForbiddenStageOperations.with_span());
+            }
+        }
+
+        self.location_mask.clear();
+        let mut argument_built_ins = crate::FastHashSet::default();
+        // TODO: add span info to function arguments
+        for (index, fa) in ep.function.arguments.iter().enumerate() {
+            let mut ctx = VaryingContext {
+                stage: ep.stage,
+                output: false,
+                types: &module.types,
+                type_info: &self.types,
+                location_mask: &mut self.location_mask,
+                built_ins: &mut argument_built_ins,
+                capabilities: self.capabilities,
+
+                #[cfg(feature = "validate")]
+                flags: self.flags,
+            };
+            ctx.validate(fa.ty, fa.binding.as_ref())
+                .map_err_inner(|e| EntryPointError::Argument(index as u32, e).with_span())?;
+        }
+
+        self.location_mask.clear();
+        if let Some(ref fr) = ep.function.result {
+            let mut result_built_ins = crate::FastHashSet::default();
+            let mut ctx = VaryingContext {
+                stage: ep.stage,
+                output: true,
+                types: &module.types,
+                type_info: &self.types,
+                location_mask: &mut self.location_mask,
+                built_ins: &mut result_built_ins,
+                capabilities: self.capabilities,
+
+                #[cfg(feature = "validate")]
+                flags: self.flags,
+            };
+            ctx.validate(fr.ty, fr.binding.as_ref())
+                .map_err_inner(|e| EntryPointError::Result(e).with_span())?;
+
+            #[cfg(feature = "validate")]
+            if ep.stage == crate::ShaderStage::Vertex
+                && !result_built_ins.contains(&crate::BuiltIn::Position { invariant: false })
+            {
+                return Err(EntryPointError::MissingVertexOutputPosition.with_span());
+            }
+        } else if ep.stage == crate::ShaderStage::Vertex {
+            #[cfg(feature = "validate")]
+            return Err(EntryPointError::MissingVertexOutputPosition.with_span());
+        }
+
+        for bg in self.bind_group_masks.iter_mut() {
+            bg.clear();
+        }
+
+        #[cfg(feature = "validate")]
+        for (var_handle, var) in module.global_variables.iter() {
+            let usage = info[var_handle];
+            if usage.is_empty() {
+                continue;
+            }
+
+            let allowed_usage = match var.space {
+                crate::AddressSpace::Function => unreachable!(),
+                crate::AddressSpace::Uniform => GlobalUse::READ | GlobalUse::QUERY,
+                crate::AddressSpace::Storage { access } => storage_usage(access),
+                crate::AddressSpace::Handle => match module.types[var.ty].inner {
+                    crate::TypeInner::BindingArray { base, .. } => match module.types[base].inner {
+                        crate::TypeInner::Image {
+                            class: crate::ImageClass::Storage { access, .. },
+                            ..
+                        } => storage_usage(access),
+                        _ => GlobalUse::READ | GlobalUse::QUERY,
+                    },
+                    crate::TypeInner::Image {
+                        class: crate::ImageClass::Storage { access, .. },
+                        ..
+                    } => storage_usage(access),
+                    _ => GlobalUse::READ | GlobalUse::QUERY,
+                },
+                crate::AddressSpace::Private | crate::AddressSpace::WorkGroup => GlobalUse::all(),
+                crate::AddressSpace::PushConstant => GlobalUse::READ,
+            };
+            if !allowed_usage.contains(usage) {
+                log::warn!("\tUsage error for: {:?}", var);
+                log::warn!(
+                    "\tAllowed usage: {:?}, requested: {:?}",
+                    allowed_usage,
+                    usage
+                );
+                return Err(EntryPointError::InvalidGlobalUsage(var_handle, usage)
+                    .with_span_handle(var_handle, &module.global_variables));
+            }
+
+            if let Some(ref bind) = var.binding {
+                while self.bind_group_masks.len() <= bind.group as usize {
+                    self.bind_group_masks.push(BitSet::new());
+                }
+                if !self.bind_group_masks[bind.group as usize].insert(bind.binding as usize) {
+                    if self.flags.contains(super::ValidationFlags::BINDINGS) {
+                        return Err(EntryPointError::BindingCollision(var_handle)
+                            .with_span_handle(var_handle, &module.global_variables));
+                    }
+                }
+            }
+        }
+
+        Ok(info)
+    }
+}

third-party/vendor/naga/src/valid/mod.rs

@@ -0,0 +1,495 @@
+/*!
+Shader validator.
+*/
+
+mod analyzer;
+mod compose;
+mod expression;
+mod function;
+mod handles;
+mod interface;
+mod r#type;
+
+use crate::{
+    arena::Handle,
+    proc::{LayoutError, Layouter, TypeResolution},
+    FastHashSet,
+};
+use bit_set::BitSet;
+use std::ops;
+
+//TODO: analyze the model at the same time as we validate it,
+// merge the corresponding matches over expressions and statements.
+
+use crate::span::{AddSpan as _, WithSpan};
+pub use analyzer::{ExpressionInfo, FunctionInfo, GlobalUse, Uniformity, UniformityRequirements};
+pub use compose::ComposeError;
+pub use expression::ExpressionError;
+pub use function::{CallError, FunctionError, LocalVariableError};
+pub use interface::{EntryPointError, GlobalVariableError, VaryingError};
+pub use r#type::{Disalignment, TypeError, TypeFlags};
+
+use self::handles::InvalidHandleError;
+
+bitflags::bitflags! {
+    /// Validation flags.
+    ///
+    /// If you are working with trusted shaders, then you may be able
+    /// to save some time by skipping validation.
+    ///
+    /// If you do not perform full validation, invalid shaders may
+    /// cause Naga to panic. If you do perform full validation and
+    /// [`Validator::validate`] returns `Ok`, then Naga promises that
+    /// code generation will either succeed or return an error; it
+    /// should never panic.
+    ///
+    /// The default value for `ValidationFlags` is
+    /// `ValidationFlags::all()`. If Naga's `"validate"` feature is
+    /// enabled, this requests full validation; otherwise, this
+    /// requests no validation. (The `"validate"` feature is disabled
+    /// by default.)
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct ValidationFlags: u8 {
+        /// Expressions.
+        #[cfg(feature = "validate")]
+        const EXPRESSIONS = 0x1;
+        /// Statements and blocks of them.
+        #[cfg(feature = "validate")]
+        const BLOCKS = 0x2;
+        /// Uniformity of control flow for operations that require it.
+        #[cfg(feature = "validate")]
+        const CONTROL_FLOW_UNIFORMITY = 0x4;
+        /// Host-shareable structure layouts.
+        #[cfg(feature = "validate")]
+        const STRUCT_LAYOUTS = 0x8;
+        /// Constants.
+        #[cfg(feature = "validate")]
+        const CONSTANTS = 0x10;
+        /// Group, binding, and location attributes.
+        #[cfg(feature = "validate")]
+        const BINDINGS = 0x20;
+    }
+}
+
+impl Default for ValidationFlags {
+    fn default() -> Self {
+        Self::all()
+    }
+}
+
+bitflags::bitflags! {
+    /// Allowed IR capabilities.
+    #[must_use]
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct Capabilities: u16 {
+        /// Support for [`AddressSpace:PushConstant`].
+        const PUSH_CONSTANT = 0x1;
+        /// Float values with width = 8.
+        const FLOAT64 = 0x2;
+        /// Support for [`Builtin:PrimitiveIndex`].
+        const PRIMITIVE_INDEX = 0x4;
+        /// Support for non-uniform indexing of sampled textures and storage buffer arrays.
+        const SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING = 0x8;
+        /// Support for non-uniform indexing of uniform buffers and storage texture arrays.
+        const UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING = 0x10;
+        /// Support for non-uniform indexing of samplers.
+        const SAMPLER_NON_UNIFORM_INDEXING = 0x20;
+        /// Support for [`Builtin::ClipDistance`].
+        const CLIP_DISTANCE = 0x40;
+        /// Support for [`Builtin::CullDistance`].
+        const CULL_DISTANCE = 0x80;
+        /// Support for 16-bit normalized storage texture formats.
+        const STORAGE_TEXTURE_16BIT_NORM_FORMATS = 0x100;
+        /// Support for [`BuiltIn::ViewIndex`].
+        const MULTIVIEW = 0x200;
+        /// Support for `early_depth_test`.
+        const EARLY_DEPTH_TEST = 0x400;
+        /// Support for [`Builtin::SampleIndex`] and [`Sampling::Sample`].
+        const MULTISAMPLED_SHADING = 0x800;
+        /// Support for ray queries and acceleration structures.
+        const RAY_QUERY = 0x1000;
+    }
+}
+
+impl Default for Capabilities {
+    fn default() -> Self {
+        Self::MULTISAMPLED_SHADING
+    }
+}
+
+bitflags::bitflags! {
+    /// Validation flags.
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct ShaderStages: u8 {
+        const VERTEX = 0x1;
+        const FRAGMENT = 0x2;
+        const COMPUTE = 0x4;
+    }
+}
+
+#[derive(Debug)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct ModuleInfo {
+    type_flags: Vec<TypeFlags>,
+    functions: Vec<FunctionInfo>,
+    entry_points: Vec<FunctionInfo>,
+    const_expression_types: Box<[TypeResolution]>,
+}
+
+impl ops::Index<Handle<crate::Type>> for ModuleInfo {
+    type Output = TypeFlags;
+    fn index(&self, handle: Handle<crate::Type>) -> &Self::Output {
+        &self.type_flags[handle.index()]
+    }
+}
+
+impl ops::Index<Handle<crate::Function>> for ModuleInfo {
+    type Output = FunctionInfo;
+    fn index(&self, handle: Handle<crate::Function>) -> &Self::Output {
+        &self.functions[handle.index()]
+    }
+}
+
+impl ops::Index<Handle<crate::Expression>> for ModuleInfo {
+    type Output = TypeResolution;
+    fn index(&self, handle: Handle<crate::Expression>) -> &Self::Output {
+        &self.const_expression_types[handle.index()]
+    }
+}
+
+#[derive(Debug)]
+pub struct Validator {
+    flags: ValidationFlags,
+    capabilities: Capabilities,
+    types: Vec<r#type::TypeInfo>,
+    layouter: Layouter,
+    location_mask: BitSet,
+    bind_group_masks: Vec<BitSet>,
+    #[allow(dead_code)]
+    switch_values: FastHashSet<crate::SwitchValue>,
+    valid_expression_list: Vec<Handle<crate::Expression>>,
+    valid_expression_set: BitSet,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ConstExpressionError {
+    #[error("The expression is not a constant expression")]
+    NonConst,
+    #[error(transparent)]
+    Compose(#[from] ComposeError),
+    #[error("Type resolution failed")]
+    Type(#[from] crate::proc::ResolveError),
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ConstantError {
+    #[error("The type doesn't match the constant")]
+    InvalidType,
+    #[error("The type is not constructible")]
+    NonConstructibleType,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum ValidationError {
+    #[error(transparent)]
+    InvalidHandle(#[from] InvalidHandleError),
+    #[error(transparent)]
+    Layouter(#[from] LayoutError),
+    #[error("Type {handle:?} '{name}' is invalid")]
+    Type {
+        handle: Handle<crate::Type>,
+        name: String,
+        source: TypeError,
+    },
+    #[error("Constant expression {handle:?} is invalid")]
+    ConstExpression {
+        handle: Handle<crate::Expression>,
+        source: ConstExpressionError,
+    },
+    #[error("Constant {handle:?} '{name}' is invalid")]
+    Constant {
+        handle: Handle<crate::Constant>,
+        name: String,
+        source: ConstantError,
+    },
+    #[error("Global variable {handle:?} '{name}' is invalid")]
+    GlobalVariable {
+        handle: Handle<crate::GlobalVariable>,
+        name: String,
+        source: GlobalVariableError,
+    },
+    #[error("Function {handle:?} '{name}' is invalid")]
+    Function {
+        handle: Handle<crate::Function>,
+        name: String,
+        source: FunctionError,
+    },
+    #[error("Entry point {name} at {stage:?} is invalid")]
+    EntryPoint {
+        stage: crate::ShaderStage,
+        name: String,
+        source: EntryPointError,
+    },
+    #[error("Module is corrupted")]
+    Corrupted,
+}
+
+impl crate::TypeInner {
+    #[cfg(feature = "validate")]
+    const fn is_sized(&self) -> bool {
+        match *self {
+            Self::Scalar { .. }
+            | Self::Vector { .. }
+            | Self::Matrix { .. }
+            | Self::Array {
+                size: crate::ArraySize::Constant(_),
+                ..
+            }
+            | Self::Atomic { .. }
+            | Self::Pointer { .. }
+            | Self::ValuePointer { .. }
+            | Self::Struct { .. } => true,
+            Self::Array { .. }
+            | Self::Image { .. }
+            | Self::Sampler { .. }
+            | Self::AccelerationStructure
+            | Self::RayQuery
+            | Self::BindingArray { .. } => false,
+        }
+    }
+
+    /// Return the `ImageDimension` for which `self` is an appropriate coordinate.
+    #[cfg(feature = "validate")]
+    const fn image_storage_coordinates(&self) -> Option<crate::ImageDimension> {
+        match *self {
+            Self::Scalar {
+                kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                ..
+            } => Some(crate::ImageDimension::D1),
+            Self::Vector {
+                size: crate::VectorSize::Bi,
+                kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                ..
+            } => Some(crate::ImageDimension::D2),
+            Self::Vector {
+                size: crate::VectorSize::Tri,
+                kind: crate::ScalarKind::Sint | crate::ScalarKind::Uint,
+                ..
+            } => Some(crate::ImageDimension::D3),
+            _ => None,
+        }
+    }
+}
+
+impl Validator {
+    /// Construct a new validator instance.
+    pub fn new(flags: ValidationFlags, capabilities: Capabilities) -> Self {
+        Validator {
+            flags,
+            capabilities,
+            types: Vec::new(),
+            layouter: Layouter::default(),
+            location_mask: BitSet::new(),
+            bind_group_masks: Vec::new(),
+            switch_values: FastHashSet::default(),
+            valid_expression_list: Vec::new(),
+            valid_expression_set: BitSet::new(),
+        }
+    }
+
+    /// Reset the validator internals
+    pub fn reset(&mut self) {
+        self.types.clear();
+        self.layouter.clear();
+        self.location_mask.clear();
+        self.bind_group_masks.clear();
+        self.switch_values.clear();
+        self.valid_expression_list.clear();
+        self.valid_expression_set.clear();
+    }
+
+    #[cfg(feature = "validate")]
+    fn validate_constant(
+        &self,
+        handle: Handle<crate::Constant>,
+        gctx: crate::proc::GlobalCtx,
+        mod_info: &ModuleInfo,
+    ) -> Result<(), ConstantError> {
+        let con = &gctx.constants[handle];
+
+        let type_info = &self.types[con.ty.index()];
+        if !type_info.flags.contains(TypeFlags::CONSTRUCTIBLE) {
+            return Err(ConstantError::NonConstructibleType);
+        }
+
+        let decl_ty = &gctx.types[con.ty].inner;
+        let init_ty = mod_info[con.init].inner_with(gctx.types);
+        if !decl_ty.equivalent(init_ty, gctx.types) {
+            return Err(ConstantError::InvalidType);
+        }
+
+        Ok(())
+    }
+
+    /// Check the given module to be valid.
+    pub fn validate(
+        &mut self,
+        module: &crate::Module,
+    ) -> Result<ModuleInfo, WithSpan<ValidationError>> {
+        self.reset();
+        self.reset_types(module.types.len());
+
+        #[cfg(feature = "validate")]
+        Self::validate_module_handles(module).map_err(|e| e.with_span())?;
+
+        self.layouter.update(module.to_ctx()).map_err(|e| {
+            let handle = e.ty;
+            ValidationError::from(e).with_span_handle(handle, &module.types)
+        })?;
+
+        let placeholder = TypeResolution::Value(crate::TypeInner::Scalar {
+            kind: crate::ScalarKind::Bool,
+            width: 0,
+        });
+
+        let mut mod_info = ModuleInfo {
+            type_flags: Vec::with_capacity(module.types.len()),
+            functions: Vec::with_capacity(module.functions.len()),
+            entry_points: Vec::with_capacity(module.entry_points.len()),
+            const_expression_types: vec![placeholder; module.const_expressions.len()]
+                .into_boxed_slice(),
+        };
+
+        for (handle, ty) in module.types.iter() {
+            let ty_info = self
+                .validate_type(handle, module.to_ctx())
+                .map_err(|source| {
+                    ValidationError::Type {
+                        handle,
+                        name: ty.name.clone().unwrap_or_default(),
+                        source,
+                    }
+                    .with_span_handle(handle, &module.types)
+                })?;
+            mod_info.type_flags.push(ty_info.flags);
+            self.types[handle.index()] = ty_info;
+        }
+
+        {
+            let t = crate::Arena::new();
+            let resolve_context = crate::proc::ResolveContext::with_locals(module, &t, &[]);
+            for (handle, _) in module.const_expressions.iter() {
+                mod_info
+                    .process_const_expression(handle, &resolve_context, module.to_ctx())
+                    .map_err(|source| {
+                        ValidationError::ConstExpression { handle, source }
+                            .with_span_handle(handle, &module.const_expressions)
+                    })?
+            }
+        }
+
+        #[cfg(feature = "validate")]
+        if self.flags.contains(ValidationFlags::CONSTANTS) {
+            for (handle, _) in module.const_expressions.iter() {
+                self.validate_const_expression(handle, module.to_ctx(), &mut mod_info)
+                    .map_err(|source| {
+                        ValidationError::ConstExpression { handle, source }
+                            .with_span_handle(handle, &module.const_expressions)
+                    })?
+            }
+
+            for (handle, constant) in module.constants.iter() {
+                self.validate_constant(handle, module.to_ctx(), &mod_info)
+                    .map_err(|source| {
+                        ValidationError::Constant {
+                            handle,
+                            name: constant.name.clone().unwrap_or_default(),
+                            source,
+                        }
+                        .with_span_handle(handle, &module.constants)
+                    })?
+            }
+        }
+
+        #[cfg(feature = "validate")]
+        for (var_handle, var) in module.global_variables.iter() {
+            self.validate_global_var(var, module.to_ctx(), &mod_info)
+                .map_err(|source| {
+                    ValidationError::GlobalVariable {
+                        handle: var_handle,
+                        name: var.name.clone().unwrap_or_default(),
+                        source,
+                    }
+                    .with_span_handle(var_handle, &module.global_variables)
+                })?;
+        }
+
+        for (handle, fun) in module.functions.iter() {
+            match self.validate_function(fun, module, &mod_info, false) {
+                Ok(info) => mod_info.functions.push(info),
+                Err(error) => {
+                    return Err(error.and_then(|source| {
+                        ValidationError::Function {
+                            handle,
+                            name: fun.name.clone().unwrap_or_default(),
+                            source,
+                        }
+                        .with_span_handle(handle, &module.functions)
+                    }))
+                }
+            }
+        }
+
+        let mut ep_map = FastHashSet::default();
+        for ep in module.entry_points.iter() {
+            if !ep_map.insert((ep.stage, &ep.name)) {
+                return Err(ValidationError::EntryPoint {
+                    stage: ep.stage,
+                    name: ep.name.clone(),
+                    source: EntryPointError::Conflict,
+                }
+                .with_span()); // TODO: keep some EP span information?
+            }
+
+            match self.validate_entry_point(ep, module, &mod_info) {
+                Ok(info) => mod_info.entry_points.push(info),
+                Err(error) => {
+                    return Err(error.and_then(|source| {
+                        ValidationError::EntryPoint {
+                            stage: ep.stage,
+                            name: ep.name.clone(),
+                            source,
+                        }
+                        .with_span()
+                    }));
+                }
+            }
+        }
+
+        Ok(mod_info)
+    }
+}
+
+#[cfg(feature = "validate")]
+fn validate_atomic_compare_exchange_struct(
+    types: &crate::UniqueArena<crate::Type>,
+    members: &[crate::StructMember],
+    scalar_predicate: impl FnOnce(&crate::TypeInner) -> bool,
+) -> bool {
+    members.len() == 2
+        && members[0].name.as_deref() == Some("old_value")
+        && scalar_predicate(&types[members[0].ty].inner)
+        && members[1].name.as_deref() == Some("exchanged")
+        && types[members[1].ty].inner
+            == crate::TypeInner::Scalar {
+                kind: crate::ScalarKind::Bool,
+                width: crate::BOOL_WIDTH,
+            }
+}

third-party/vendor/naga/src/valid/type.rs

@@ -0,0 +1,596 @@
+use super::Capabilities;
+use crate::{arena::Handle, proc::Alignment};
+
+bitflags::bitflags! {
+    /// Flags associated with [`Type`]s by [`Validator`].
+    ///
+    /// [`Type`]: crate::Type
+    /// [`Validator`]: crate::valid::Validator
+    #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
+    #[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+    #[repr(transparent)]
+    #[derive(Clone, Copy, Debug, Eq, PartialEq)]
+    pub struct TypeFlags: u8 {
+        /// Can be used for data variables.
+        ///
+        /// This flag is required on types of local variables, function
+        /// arguments, array elements, and struct members.
+        ///
+        /// This includes all types except `Image`, `Sampler`,
+        /// and some `Pointer` types.
+        const DATA = 0x1;
+
+        /// The data type has a size known by pipeline creation time.
+        ///
+        /// Unsized types are quite restricted. The only unsized types permitted
+        /// by Naga, other than the non-[`DATA`] types like [`Image`] and
+        /// [`Sampler`], are dynamically-sized [`Array`s], and [`Struct`s] whose
+        /// last members are such arrays. See the documentation for those types
+        /// for details.
+        ///
+        /// [`DATA`]: TypeFlags::DATA
+        /// [`Image`]: crate::Type::Image
+        /// [`Sampler`]: crate::Type::Sampler
+        /// [`Array`]: crate::Type::Array
+        /// [`Struct`]: crate::Type::struct
+        const SIZED = 0x2;
+
+        /// The data can be copied around.
+        const COPY = 0x4;
+
+        /// Can be be used for user-defined IO between pipeline stages.
+        ///
+        /// This covers anything that can be in [`Location`] binding:
+        /// non-bool scalars and vectors, matrices, and structs and
+        /// arrays containing only interface types.
+        const IO_SHAREABLE = 0x8;
+
+        /// Can be used for host-shareable structures.
+        const HOST_SHAREABLE = 0x10;
+
+        /// This type can be passed as a function argument.
+        const ARGUMENT = 0x40;
+
+        /// A WGSL [constructible] type.
+        ///
+        /// The constructible types are scalars, vectors, matrices, fixed-size
+        /// arrays of constructible types, and structs whose members are all
+        /// constructible.
+        ///
+        /// [constructible]: https://gpuweb.github.io/gpuweb/wgsl/#constructible
+        const CONSTRUCTIBLE = 0x80;
+    }
+}
+
+#[derive(Clone, Copy, Debug, thiserror::Error)]
+pub enum Disalignment {
+    #[error("The array stride {stride} is not a multiple of the required alignment {alignment}")]
+    ArrayStride { stride: u32, alignment: Alignment },
+    #[error("The struct span {span}, is not a multiple of the required alignment {alignment}")]
+    StructSpan { span: u32, alignment: Alignment },
+    #[error("The struct member[{index}] offset {offset} is not a multiple of the required alignment {alignment}")]
+    MemberOffset {
+        index: u32,
+        offset: u32,
+        alignment: Alignment,
+    },
+    #[error("The struct member[{index}] offset {offset} must be at least {expected}")]
+    MemberOffsetAfterStruct {
+        index: u32,
+        offset: u32,
+        expected: u32,
+    },
+    #[error("The struct member[{index}] is not statically sized")]
+    UnsizedMember { index: u32 },
+    #[error("The type is not host-shareable")]
+    NonHostShareable,
+}
+
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum TypeError {
+    #[error("Capability {0:?} is required")]
+    MissingCapability(Capabilities),
+    #[error("The {0:?} scalar width {1} is not supported")]
+    InvalidWidth(crate::ScalarKind, crate::Bytes),
+    #[error("The {0:?} scalar width {1} is not supported for an atomic")]
+    InvalidAtomicWidth(crate::ScalarKind, crate::Bytes),
+    #[error("Invalid type for pointer target {0:?}")]
+    InvalidPointerBase(Handle<crate::Type>),
+    #[error("Unsized types like {base:?} must be in the `Storage` address space, not `{space:?}`")]
+    InvalidPointerToUnsized {
+        base: Handle<crate::Type>,
+        space: crate::AddressSpace,
+    },
+    #[error("Expected data type, found {0:?}")]
+    InvalidData(Handle<crate::Type>),
+    #[error("Base type {0:?} for the array is invalid")]
+    InvalidArrayBaseType(Handle<crate::Type>),
+    #[error("The constant {0:?} is specialized, and cannot be used as an array size")]
+    UnsupportedSpecializedArrayLength(Handle<crate::Constant>),
+    #[error("Array stride {stride} does not match the expected {expected}")]
+    InvalidArrayStride { stride: u32, expected: u32 },
+    #[error("Field '{0}' can't be dynamically-sized, has type {1:?}")]
+    InvalidDynamicArray(String, Handle<crate::Type>),
+    #[error("The base handle {0:?} has to be a struct")]
+    BindingArrayBaseTypeNotStruct(Handle<crate::Type>),
+    #[error("Structure member[{index}] at {offset} overlaps the previous member")]
+    MemberOverlap { index: u32, offset: u32 },
+    #[error(
+        "Structure member[{index}] at {offset} and size {size} crosses the structure boundary of size {span}"
+    )]
+    MemberOutOfBounds {
+        index: u32,
+        offset: u32,
+        size: u32,
+        span: u32,
+    },
+    #[error("Structure types must have at least one member")]
+    EmptyStruct,
+}
+
+// Only makes sense if `flags.contains(HOST_SHAREABLE)`
+type LayoutCompatibility = Result<Alignment, (Handle<crate::Type>, Disalignment)>;
+
+fn check_member_layout(
+    accum: &mut LayoutCompatibility,
+    member: &crate::StructMember,
+    member_index: u32,
+    member_layout: LayoutCompatibility,
+    parent_handle: Handle<crate::Type>,
+) {
+    *accum = match (*accum, member_layout) {
+        (Ok(cur_alignment), Ok(alignment)) => {
+            if alignment.is_aligned(member.offset) {
+                Ok(cur_alignment.max(alignment))
+            } else {
+                Err((
+                    parent_handle,
+                    Disalignment::MemberOffset {
+                        index: member_index,
+                        offset: member.offset,
+                        alignment,
+                    },
+                ))
+            }
+        }
+        (Err(e), _) | (_, Err(e)) => Err(e),
+    };
+}
+
+/// Determine whether a pointer in `space` can be passed as an argument.
+///
+/// If a pointer in `space` is permitted to be passed as an argument to a
+/// user-defined function, return `TypeFlags::ARGUMENT`. Otherwise, return
+/// `TypeFlags::empty()`.
+///
+/// Pointers passed as arguments to user-defined functions must be in the
+/// `Function`, `Private`, or `Workgroup` storage space.
+const fn ptr_space_argument_flag(space: crate::AddressSpace) -> TypeFlags {
+    use crate::AddressSpace as As;
+    match space {
+        As::Function | As::Private | As::WorkGroup => TypeFlags::ARGUMENT,
+        As::Uniform | As::Storage { .. } | As::Handle | As::PushConstant => TypeFlags::empty(),
+    }
+}
+
+#[derive(Clone, Debug)]
+pub(super) struct TypeInfo {
+    pub flags: TypeFlags,
+    pub uniform_layout: LayoutCompatibility,
+    pub storage_layout: LayoutCompatibility,
+}
+
+impl TypeInfo {
+    const fn dummy() -> Self {
+        TypeInfo {
+            flags: TypeFlags::empty(),
+            uniform_layout: Ok(Alignment::ONE),
+            storage_layout: Ok(Alignment::ONE),
+        }
+    }
+
+    const fn new(flags: TypeFlags, alignment: Alignment) -> Self {
+        TypeInfo {
+            flags,
+            uniform_layout: Ok(alignment),
+            storage_layout: Ok(alignment),
+        }
+    }
+}
+
+impl super::Validator {
+    const fn require_type_capability(&self, capability: Capabilities) -> Result<(), TypeError> {
+        if self.capabilities.contains(capability) {
+            Ok(())
+        } else {
+            Err(TypeError::MissingCapability(capability))
+        }
+    }
+
+    pub(super) fn check_width(
+        &self,
+        kind: crate::ScalarKind,
+        width: crate::Bytes,
+    ) -> Result<(), TypeError> {
+        let good = match kind {
+            crate::ScalarKind::Bool => width == crate::BOOL_WIDTH,
+            crate::ScalarKind::Float => {
+                if width == 8 {
+                    self.require_type_capability(Capabilities::FLOAT64)?;
+                    true
+                } else {
+                    width == 4
+                }
+            }
+            crate::ScalarKind::Sint | crate::ScalarKind::Uint => width == 4,
+        };
+        if good {
+            Ok(())
+        } else {
+            Err(TypeError::InvalidWidth(kind, width))
+        }
+    }
+
+    pub(super) fn reset_types(&mut self, size: usize) {
+        self.types.clear();
+        self.types.resize(size, TypeInfo::dummy());
+        self.layouter.clear();
+    }
+
+    pub(super) fn validate_type(
+        &self,
+        handle: Handle<crate::Type>,
+        gctx: crate::proc::GlobalCtx,
+    ) -> Result<TypeInfo, TypeError> {
+        use crate::TypeInner as Ti;
+        Ok(match gctx.types[handle].inner {
+            Ti::Scalar { kind, width } => {
+                self.check_width(kind, width)?;
+                let shareable = if kind.is_numeric() {
+                    TypeFlags::IO_SHAREABLE | TypeFlags::HOST_SHAREABLE
+                } else {
+                    TypeFlags::empty()
+                };
+                TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE
+                        | shareable,
+                    Alignment::from_width(width),
+                )
+            }
+            Ti::Vector { size, kind, width } => {
+                self.check_width(kind, width)?;
+                let shareable = if kind.is_numeric() {
+                    TypeFlags::IO_SHAREABLE | TypeFlags::HOST_SHAREABLE
+                } else {
+                    TypeFlags::empty()
+                };
+                TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE
+                        | shareable,
+                    Alignment::from(size) * Alignment::from_width(width),
+                )
+            }
+            Ti::Matrix {
+                columns: _,
+                rows,
+                width,
+            } => {
+                self.check_width(crate::ScalarKind::Float, width)?;
+                TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE,
+                    Alignment::from(rows) * Alignment::from_width(width),
+                )
+            }
+            Ti::Atomic { kind, width } => {
+                let good = match kind {
+                    crate::ScalarKind::Bool | crate::ScalarKind::Float => false,
+                    crate::ScalarKind::Sint | crate::ScalarKind::Uint => width == 4,
+                };
+                if !good {
+                    return Err(TypeError::InvalidAtomicWidth(kind, width));
+                }
+                TypeInfo::new(
+                    TypeFlags::DATA | TypeFlags::SIZED | TypeFlags::HOST_SHAREABLE,
+                    Alignment::from_width(width),
+                )
+            }
+            Ti::Pointer { base, space } => {
+                use crate::AddressSpace as As;
+
+                let base_info = &self.types[base.index()];
+                if !base_info.flags.contains(TypeFlags::DATA) {
+                    return Err(TypeError::InvalidPointerBase(base));
+                }
+
+                // Runtime-sized values can only live in the `Storage` storage
+                // space, so it's useless to have a pointer to such a type in
+                // any other space.
+                //
+                // Detecting this problem here prevents the definition of
+                // functions like:
+                //
+                //     fn f(p: ptr<workgroup, UnsizedType>) -> ... { ... }
+                //
+                // which would otherwise be permitted, but uncallable. (They
+                // may also present difficulties in code generation).
+                if !base_info.flags.contains(TypeFlags::SIZED) {
+                    match space {
+                        As::Storage { .. } => {}
+                        _ => {
+                            return Err(TypeError::InvalidPointerToUnsized { base, space });
+                        }
+                    }
+                }
+
+                // `Validator::validate_function` actually checks the storage
+                // space of pointer arguments explicitly before checking the
+                // `ARGUMENT` flag, to give better error messages. But it seems
+                // best to set `ARGUMENT` accurately anyway.
+                let argument_flag = ptr_space_argument_flag(space);
+
+                // Pointers cannot be stored in variables, structure members, or
+                // array elements, so we do not mark them as `DATA`.
+                TypeInfo::new(
+                    argument_flag | TypeFlags::SIZED | TypeFlags::COPY,
+                    Alignment::ONE,
+                )
+            }
+            Ti::ValuePointer {
+                size: _,
+                kind,
+                width,
+                space,
+            } => {
+                // ValuePointer should be treated the same way as the equivalent
+                // Pointer / Scalar / Vector combination, so each step in those
+                // variants' match arms should have a counterpart here.
+                //
+                // However, some cases are trivial: All our implicit base types
+                // are DATA and SIZED, so we can never return
+                // `InvalidPointerBase` or `InvalidPointerToUnsized`.
+                self.check_width(kind, width)?;
+
+                // `Validator::validate_function` actually checks the storage
+                // space of pointer arguments explicitly before checking the
+                // `ARGUMENT` flag, to give better error messages. But it seems
+                // best to set `ARGUMENT` accurately anyway.
+                let argument_flag = ptr_space_argument_flag(space);
+
+                // Pointers cannot be stored in variables, structure members, or
+                // array elements, so we do not mark them as `DATA`.
+                TypeInfo::new(
+                    argument_flag | TypeFlags::SIZED | TypeFlags::COPY,
+                    Alignment::ONE,
+                )
+            }
+            Ti::Array { base, size, stride } => {
+                let base_info = &self.types[base.index()];
+                if !base_info.flags.contains(TypeFlags::DATA | TypeFlags::SIZED) {
+                    return Err(TypeError::InvalidArrayBaseType(base));
+                }
+
+                let base_layout = self.layouter[base];
+                let general_alignment = base_layout.alignment;
+                let uniform_layout = match base_info.uniform_layout {
+                    Ok(base_alignment) => {
+                        let alignment = base_alignment
+                            .max(general_alignment)
+                            .max(Alignment::MIN_UNIFORM);
+                        if alignment.is_aligned(stride) {
+                            Ok(alignment)
+                        } else {
+                            Err((handle, Disalignment::ArrayStride { stride, alignment }))
+                        }
+                    }
+                    Err(e) => Err(e),
+                };
+                let storage_layout = match base_info.storage_layout {
+                    Ok(base_alignment) => {
+                        let alignment = base_alignment.max(general_alignment);
+                        if alignment.is_aligned(stride) {
+                            Ok(alignment)
+                        } else {
+                            Err((handle, Disalignment::ArrayStride { stride, alignment }))
+                        }
+                    }
+                    Err(e) => Err(e),
+                };
+
+                let type_info_mask = match size {
+                    crate::ArraySize::Constant(_) => {
+                        TypeFlags::DATA
+                            | TypeFlags::SIZED
+                            | TypeFlags::COPY
+                            | TypeFlags::HOST_SHAREABLE
+                            | TypeFlags::ARGUMENT
+                            | TypeFlags::CONSTRUCTIBLE
+                    }
+                    crate::ArraySize::Dynamic => {
+                        // Non-SIZED types may only appear as the last element of a structure.
+                        // This is enforced by checks for SIZED-ness for all compound types,
+                        // and a special case for structs.
+                        TypeFlags::DATA | TypeFlags::COPY | TypeFlags::HOST_SHAREABLE
+                    }
+                };
+
+                TypeInfo {
+                    flags: base_info.flags & type_info_mask,
+                    uniform_layout,
+                    storage_layout,
+                }
+            }
+            Ti::Struct { ref members, span } => {
+                if members.is_empty() {
+                    return Err(TypeError::EmptyStruct);
+                }
+
+                let mut ti = TypeInfo::new(
+                    TypeFlags::DATA
+                        | TypeFlags::SIZED
+                        | TypeFlags::COPY
+                        | TypeFlags::HOST_SHAREABLE
+                        | TypeFlags::IO_SHAREABLE
+                        | TypeFlags::ARGUMENT
+                        | TypeFlags::CONSTRUCTIBLE,
+                    Alignment::ONE,
+                );
+                ti.uniform_layout = Ok(Alignment::MIN_UNIFORM);
+
+                let mut min_offset = 0;
+
+                let mut prev_struct_data: Option<(u32, u32)> = None;
+
+                for (i, member) in members.iter().enumerate() {
+                    let base_info = &self.types[member.ty.index()];
+                    if !base_info.flags.contains(TypeFlags::DATA) {
+                        return Err(TypeError::InvalidData(member.ty));
+                    }
+                    if !base_info.flags.contains(TypeFlags::HOST_SHAREABLE) {
+                        if ti.uniform_layout.is_ok() {
+                            ti.uniform_layout = Err((member.ty, Disalignment::NonHostShareable));
+                        }
+                        if ti.storage_layout.is_ok() {
+                            ti.storage_layout = Err((member.ty, Disalignment::NonHostShareable));
+                        }
+                    }
+                    ti.flags &= base_info.flags;
+
+                    if member.offset < min_offset {
+                        // HACK: this could be nicer. We want to allow some structures
+                        // to not bother with offsets/alignments if they are never
+                        // used for host sharing.
+                        if member.offset == 0 {
+                            ti.flags.set(TypeFlags::HOST_SHAREABLE, false);
+                        } else {
+                            return Err(TypeError::MemberOverlap {
+                                index: i as u32,
+                                offset: member.offset,
+                            });
+                        }
+                    }
+
+                    let base_size = gctx.types[member.ty].inner.size(gctx);
+                    min_offset = member.offset + base_size;
+                    if min_offset > span {
+                        return Err(TypeError::MemberOutOfBounds {
+                            index: i as u32,
+                            offset: member.offset,
+                            size: base_size,
+                            span,
+                        });
+                    }
+
+                    check_member_layout(
+                        &mut ti.uniform_layout,
+                        member,
+                        i as u32,
+                        base_info.uniform_layout,
+                        handle,
+                    );
+                    check_member_layout(
+                        &mut ti.storage_layout,
+                        member,
+                        i as u32,
+                        base_info.storage_layout,
+                        handle,
+                    );
+
+                    // Validate rule: If a structure member itself has a structure type S,
+                    // then the number of bytes between the start of that member and
+                    // the start of any following member must be at least roundUp(16, SizeOf(S)).
+                    if let Some((span, offset)) = prev_struct_data {
+                        let diff = member.offset - offset;
+                        let min = Alignment::MIN_UNIFORM.round_up(span);
+                        if diff < min {
+                            ti.uniform_layout = Err((
+                                handle,
+                                Disalignment::MemberOffsetAfterStruct {
+                                    index: i as u32,
+                                    offset: member.offset,
+                                    expected: offset + min,
+                                },
+                            ));
+                        }
+                    };
+
+                    prev_struct_data = match gctx.types[member.ty].inner {
+                        crate::TypeInner::Struct { span, .. } => Some((span, member.offset)),
+                        _ => None,
+                    };
+
+                    // The last field may be an unsized array.
+                    if !base_info.flags.contains(TypeFlags::SIZED) {
+                        let is_array = match gctx.types[member.ty].inner {
+                            crate::TypeInner::Array { .. } => true,
+                            _ => false,
+                        };
+                        if !is_array || i + 1 != members.len() {
+                            let name = member.name.clone().unwrap_or_default();
+                            return Err(TypeError::InvalidDynamicArray(name, member.ty));
+                        }
+                        if ti.uniform_layout.is_ok() {
+                            ti.uniform_layout =
+                                Err((handle, Disalignment::UnsizedMember { index: i as u32 }));
+                        }
+                    }
+                }
+
+                let alignment = self.layouter[handle].alignment;
+                if !alignment.is_aligned(span) {
+                    ti.uniform_layout = Err((handle, Disalignment::StructSpan { span, alignment }));
+                    ti.storage_layout = Err((handle, Disalignment::StructSpan { span, alignment }));
+                }
+
+                ti
+            }
+            Ti::Image { .. } | Ti::Sampler { .. } => {
+                TypeInfo::new(TypeFlags::ARGUMENT, Alignment::ONE)
+            }
+            Ti::AccelerationStructure => {
+                self.require_type_capability(Capabilities::RAY_QUERY)?;
+                TypeInfo::new(TypeFlags::ARGUMENT, Alignment::ONE)
+            }
+            Ti::RayQuery => {
+                self.require_type_capability(Capabilities::RAY_QUERY)?;
+                TypeInfo::new(TypeFlags::DATA | TypeFlags::SIZED, Alignment::ONE)
+            }
+            Ti::BindingArray { base, size } => {
+                if base >= handle {
+                    return Err(TypeError::InvalidArrayBaseType(base));
+                }
+                let type_info_mask = match size {
+                    crate::ArraySize::Constant(_) => TypeFlags::SIZED | TypeFlags::HOST_SHAREABLE,
+                    crate::ArraySize::Dynamic => {
+                        // Final type is non-sized
+                        TypeFlags::HOST_SHAREABLE
+                    }
+                };
+                let base_info = &self.types[base.index()];
+
+                if base_info.flags.contains(TypeFlags::DATA) {
+                    // Currently Naga only supports binding arrays of structs for non-handle types.
+                    match gctx.types[base].inner {
+                        crate::TypeInner::Struct { .. } => {}
+                        _ => return Err(TypeError::BindingArrayBaseTypeNotStruct(base)),
+                    };
+                }
+
+                TypeInfo::new(base_info.flags & type_info_mask, Alignment::ONE)
+            }
+        })
+    }
+}