diff options
Diffstat (limited to 'third_party/rust/naga/src/front/wgsl/lower/construction.rs')
-rw-r--r-- | third_party/rust/naga/src/front/wgsl/lower/construction.rs | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/third_party/rust/naga/src/front/wgsl/lower/construction.rs b/third_party/rust/naga/src/front/wgsl/lower/construction.rs new file mode 100644 index 0000000000..de0d11d227 --- /dev/null +++ b/third_party/rust/naga/src/front/wgsl/lower/construction.rs @@ -0,0 +1,616 @@ +use std::num::NonZeroU32; + +use crate::front::wgsl::parse::ast; +use crate::{Handle, Span}; + +use crate::front::wgsl::error::Error; +use crate::front::wgsl::lower::{ExpressionContext, Lowerer}; + +/// A cooked form of `ast::ConstructorType` that uses Naga types whenever +/// possible. +enum Constructor<T> { + /// A vector construction whose component type is inferred from the + /// argument: `vec3(1.0)`. + PartialVector { size: crate::VectorSize }, + + /// A matrix construction whose component type is inferred from the + /// argument: `mat2x2(1,2,3,4)`. + PartialMatrix { + columns: crate::VectorSize, + rows: crate::VectorSize, + }, + + /// An array whose component type and size are inferred from the arguments: + /// `array(3,4,5)`. + PartialArray, + + /// A known Naga type. + /// + /// When we match on this type, we need to see the `TypeInner` here, but at + /// the point that we build this value we'll still need mutable access to + /// the module later. To avoid borrowing from the module, the type parameter + /// `T` is `Handle<Type>` initially. Then we use `borrow_inner` to produce a + /// version holding a tuple `(Handle<Type>, &TypeInner)`. + Type(T), +} + +impl Constructor<Handle<crate::Type>> { + /// Return an equivalent `Constructor` value that includes borrowed + /// `TypeInner` values alongside any type handles. + /// + /// The returned form is more convenient to match on, since the patterns + /// can actually see what the handle refers to. + fn borrow_inner( + self, + module: &crate::Module, + ) -> Constructor<(Handle<crate::Type>, &crate::TypeInner)> { + match self { + Constructor::PartialVector { size } => Constructor::PartialVector { size }, + Constructor::PartialMatrix { columns, rows } => { + Constructor::PartialMatrix { columns, rows } + } + Constructor::PartialArray => Constructor::PartialArray, + Constructor::Type(handle) => Constructor::Type((handle, &module.types[handle].inner)), + } + } +} + +impl Constructor<(Handle<crate::Type>, &crate::TypeInner)> { + fn to_error_string(&self, ctx: &ExpressionContext) -> String { + match *self { + Self::PartialVector { size } => { + format!("vec{}<?>", size as u32,) + } + Self::PartialMatrix { columns, rows } => { + format!("mat{}x{}<?>", columns as u32, rows as u32,) + } + Self::PartialArray => "array<?, ?>".to_string(), + Self::Type((handle, _inner)) => handle.to_wgsl(&ctx.module.to_ctx()), + } + } +} + +enum Components<'a> { + None, + One { + component: Handle<crate::Expression>, + span: Span, + ty_inner: &'a crate::TypeInner, + }, + Many { + components: Vec<Handle<crate::Expression>>, + spans: Vec<Span>, + }, +} + +impl Components<'_> { + fn into_components_vec(self) -> Vec<Handle<crate::Expression>> { + match self { + Self::None => vec![], + Self::One { component, .. } => vec![component], + Self::Many { components, .. } => components, + } + } +} + +impl<'source, 'temp> Lowerer<'source, 'temp> { + /// Generate Naga IR for a type constructor expression. + /// + /// The `constructor` value represents the head of the constructor + /// expression, which is at least a hint of which type is being built; if + /// it's one of the `Partial` variants, we need to consider the argument + /// types as well. + /// + /// This is used for [`Construct`] expressions, but also for [`Call`] + /// expressions, once we've determined that the "callable" (in WGSL spec + /// terms) is actually a type. + /// + /// [`Construct`]: ast::Expression::Construct + /// [`Call`]: ast::Expression::Call + pub fn construct( + &mut self, + span: Span, + constructor: &ast::ConstructorType<'source>, + ty_span: Span, + components: &[Handle<ast::Expression<'source>>], + ctx: &mut ExpressionContext<'source, '_, '_>, + ) -> Result<Handle<crate::Expression>, Error<'source>> { + use crate::proc::TypeResolution as Tr; + + let constructor_h = self.constructor(constructor, ctx)?; + + let components = match *components { + [] => Components::None, + [component] => { + let span = ctx.ast_expressions.get_span(component); + let component = self.expression_for_abstract(component, ctx)?; + let ty_inner = super::resolve_inner!(ctx, component); + + Components::One { + component, + span, + ty_inner, + } + } + ref ast_components @ [_, _, ..] => { + let components = ast_components + .iter() + .map(|&expr| self.expression_for_abstract(expr, ctx)) + .collect::<Result<_, _>>()?; + let spans = ast_components + .iter() + .map(|&expr| ctx.ast_expressions.get_span(expr)) + .collect(); + + for &component in &components { + ctx.grow_types(component)?; + } + + Components::Many { components, spans } + } + }; + + // Even though we computed `constructor` above, wait until now to borrow + // a reference to the `TypeInner`, so that the component-handling code + // above can have mutable access to the type arena. + let constructor = constructor_h.borrow_inner(ctx.module); + + let expr; + match (components, constructor) { + // Empty constructor + (Components::None, dst_ty) => match dst_ty { + Constructor::Type((result_ty, _)) => { + return ctx.append_expression(crate::Expression::ZeroValue(result_ty), span) + } + Constructor::PartialVector { .. } + | Constructor::PartialMatrix { .. } + | Constructor::PartialArray => { + // We have no arguments from which to infer the result type, so + // partial constructors aren't acceptable here. + return Err(Error::TypeNotInferable(ty_span)); + } + }, + + // Scalar constructor & conversion (scalar -> scalar) + ( + Components::One { + component, + ty_inner: &crate::TypeInner::Scalar { .. }, + .. + }, + Constructor::Type((_, &crate::TypeInner::Scalar(scalar))), + ) => { + expr = crate::Expression::As { + expr: component, + kind: scalar.kind, + convert: Some(scalar.width), + }; + } + + // Vector conversion (vector -> vector) + ( + Components::One { + component, + ty_inner: &crate::TypeInner::Vector { size: src_size, .. }, + .. + }, + Constructor::Type(( + _, + &crate::TypeInner::Vector { + size: dst_size, + scalar: dst_scalar, + }, + )), + ) if dst_size == src_size => { + expr = crate::Expression::As { + expr: component, + kind: dst_scalar.kind, + convert: Some(dst_scalar.width), + }; + } + + // Vector conversion (vector -> vector) - partial + ( + Components::One { + component, + ty_inner: &crate::TypeInner::Vector { size: src_size, .. }, + .. + }, + Constructor::PartialVector { size: dst_size }, + ) if dst_size == src_size => { + // This is a trivial conversion: the sizes match, and a Partial + // constructor doesn't specify a scalar type, so nothing can + // possibly happen. + return Ok(component); + } + + // Matrix conversion (matrix -> matrix) + ( + Components::One { + component, + ty_inner: + &crate::TypeInner::Matrix { + columns: src_columns, + rows: src_rows, + .. + }, + .. + }, + Constructor::Type(( + _, + &crate::TypeInner::Matrix { + columns: dst_columns, + rows: dst_rows, + scalar: dst_scalar, + }, + )), + ) if dst_columns == src_columns && dst_rows == src_rows => { + expr = crate::Expression::As { + expr: component, + kind: dst_scalar.kind, + convert: Some(dst_scalar.width), + }; + } + + // Matrix conversion (matrix -> matrix) - partial + ( + Components::One { + component, + ty_inner: + &crate::TypeInner::Matrix { + columns: src_columns, + rows: src_rows, + .. + }, + .. + }, + Constructor::PartialMatrix { + columns: dst_columns, + rows: dst_rows, + }, + ) if dst_columns == src_columns && dst_rows == src_rows => { + // This is a trivial conversion: the sizes match, and a Partial + // constructor doesn't specify a scalar type, so nothing can + // possibly happen. + return Ok(component); + } + + // Vector constructor (splat) - infer type + ( + Components::One { + component, + ty_inner: &crate::TypeInner::Scalar { .. }, + .. + }, + Constructor::PartialVector { size }, + ) => { + expr = crate::Expression::Splat { + size, + value: component, + }; + } + + // Vector constructor (splat) + ( + Components::One { + mut component, + ty_inner: &crate::TypeInner::Scalar(_), + .. + }, + Constructor::Type((_, &crate::TypeInner::Vector { size, scalar })), + ) => { + ctx.convert_slice_to_common_leaf_scalar( + std::slice::from_mut(&mut component), + scalar, + )?; + expr = crate::Expression::Splat { + size, + value: component, + }; + } + + // Vector constructor (by elements), partial + ( + Components::Many { + mut components, + spans, + }, + Constructor::PartialVector { size }, + ) => { + let consensus_scalar = + ctx.automatic_conversion_consensus(&components) + .map_err(|index| { + Error::InvalidConstructorComponentType(spans[index], index as i32) + })?; + ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?; + let inner = consensus_scalar.to_inner_vector(size); + let ty = ctx.ensure_type_exists(inner); + expr = crate::Expression::Compose { ty, components }; + } + + // Vector constructor (by elements), full type given + ( + Components::Many { mut components, .. }, + Constructor::Type((ty, &crate::TypeInner::Vector { scalar, .. })), + ) => { + ctx.try_automatic_conversions_for_vector(&mut components, scalar, ty_span)?; + expr = crate::Expression::Compose { ty, components }; + } + + // Matrix constructor (by elements), partial + ( + Components::Many { + mut components, + spans, + }, + Constructor::PartialMatrix { columns, rows }, + ) if components.len() == columns as usize * rows as usize => { + let consensus_scalar = + ctx.automatic_conversion_consensus(&components) + .map_err(|index| { + Error::InvalidConstructorComponentType(spans[index], index as i32) + })?; + // We actually only accept floating-point elements. + let consensus_scalar = consensus_scalar + .automatic_conversion_combine(crate::Scalar::ABSTRACT_FLOAT) + .unwrap_or(consensus_scalar); + ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?; + let vec_ty = ctx.ensure_type_exists(consensus_scalar.to_inner_vector(rows)); + + let components = components + .chunks(rows as usize) + .map(|vec_components| { + ctx.append_expression( + crate::Expression::Compose { + ty: vec_ty, + components: Vec::from(vec_components), + }, + Default::default(), + ) + }) + .collect::<Result<Vec<_>, _>>()?; + + let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix { + columns, + rows, + scalar: consensus_scalar, + }); + expr = crate::Expression::Compose { ty, components }; + } + + // Matrix constructor (by elements), type given + ( + Components::Many { mut components, .. }, + Constructor::Type(( + _, + &crate::TypeInner::Matrix { + columns, + rows, + scalar, + }, + )), + ) if components.len() == columns as usize * rows as usize => { + let element = Tr::Value(crate::TypeInner::Scalar(scalar)); + ctx.try_automatic_conversions_slice(&mut components, &element, ty_span)?; + let vec_ty = ctx.ensure_type_exists(scalar.to_inner_vector(rows)); + + let components = components + .chunks(rows as usize) + .map(|vec_components| { + ctx.append_expression( + crate::Expression::Compose { + ty: vec_ty, + components: Vec::from(vec_components), + }, + Default::default(), + ) + }) + .collect::<Result<Vec<_>, _>>()?; + + let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix { + columns, + rows, + scalar, + }); + expr = crate::Expression::Compose { ty, components }; + } + + // Matrix constructor (by columns), partial + ( + Components::Many { + mut components, + spans, + }, + Constructor::PartialMatrix { columns, rows }, + ) => { + let consensus_scalar = + ctx.automatic_conversion_consensus(&components) + .map_err(|index| { + Error::InvalidConstructorComponentType(spans[index], index as i32) + })?; + ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?; + let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix { + columns, + rows, + scalar: consensus_scalar, + }); + expr = crate::Expression::Compose { ty, components }; + } + + // Matrix constructor (by columns), type given + ( + Components::Many { mut components, .. }, + Constructor::Type(( + ty, + &crate::TypeInner::Matrix { + columns: _, + rows, + scalar, + }, + )), + ) => { + let component_ty = crate::TypeInner::Vector { size: rows, scalar }; + ctx.try_automatic_conversions_slice( + &mut components, + &Tr::Value(component_ty), + ty_span, + )?; + expr = crate::Expression::Compose { ty, components }; + } + + // Array constructor - infer type + (components, Constructor::PartialArray) => { + let mut components = components.into_components_vec(); + if let Ok(consensus_scalar) = ctx.automatic_conversion_consensus(&components) { + // Note that this will *not* necessarily convert all the + // components to the same type! The `automatic_conversion_consensus` + // method only considers the parameters' leaf scalar + // types; the parameters themselves could be any mix of + // vectors, matrices, and scalars. + // + // But *if* it is possible for this array construction + // expression to be well-typed at all, then all the + // parameters must have the same type constructors (vec, + // matrix, scalar) applied to their leaf scalars, so + // reconciling their scalars is always the right thing to + // do. And if this array construction is not well-typed, + // these conversions will not make it so, and we can let + // validation catch the error. + ctx.convert_slice_to_common_leaf_scalar(&mut components, consensus_scalar)?; + } else { + // There's no consensus scalar. Emit the `Compose` + // expression anyway, and let validation catch the problem. + } + + let base = ctx.register_type(components[0])?; + + let inner = crate::TypeInner::Array { + base, + size: crate::ArraySize::Constant( + NonZeroU32::new(u32::try_from(components.len()).unwrap()).unwrap(), + ), + stride: { + self.layouter.update(ctx.module.to_ctx()).unwrap(); + self.layouter[base].to_stride() + }, + }; + let ty = ctx.ensure_type_exists(inner); + + expr = crate::Expression::Compose { ty, components }; + } + + // Array constructor, explicit type + (components, Constructor::Type((ty, &crate::TypeInner::Array { base, .. }))) => { + let mut components = components.into_components_vec(); + ctx.try_automatic_conversions_slice(&mut components, &Tr::Handle(base), ty_span)?; + expr = crate::Expression::Compose { ty, components }; + } + + // Struct constructor + ( + components, + Constructor::Type((ty, &crate::TypeInner::Struct { ref members, .. })), + ) => { + let mut components = components.into_components_vec(); + let struct_ty_span = ctx.module.types.get_span(ty); + + // Make a vector of the members' type handles in advance, to + // avoid borrowing `members` from `ctx` while we generate + // new code. + let members: Vec<Handle<crate::Type>> = members.iter().map(|m| m.ty).collect(); + + for (component, &ty) in components.iter_mut().zip(&members) { + *component = + ctx.try_automatic_conversions(*component, &Tr::Handle(ty), struct_ty_span)?; + } + expr = crate::Expression::Compose { ty, components }; + } + + // ERRORS + + // Bad conversion (type cast) + (Components::One { span, ty_inner, .. }, constructor) => { + let from_type = ty_inner.to_wgsl(&ctx.module.to_ctx()); + return Err(Error::BadTypeCast { + span, + from_type, + to_type: constructor.to_error_string(ctx), + }); + } + + // Too many parameters for scalar constructor + ( + Components::Many { spans, .. }, + Constructor::Type((_, &crate::TypeInner::Scalar { .. })), + ) => { + let span = spans[1].until(spans.last().unwrap()); + return Err(Error::UnexpectedComponents(span)); + } + + // Other types can't be constructed + _ => return Err(Error::TypeNotConstructible(ty_span)), + } + + let expr = ctx.append_expression(expr, span)?; + Ok(expr) + } + + /// Build a [`Constructor`] for a WGSL construction expression. + /// + /// If `constructor` conveys enough information to determine which Naga [`Type`] + /// we're actually building (i.e., it's not a partial constructor), then + /// ensure the `Type` exists in [`ctx.module`], and return + /// [`Constructor::Type`]. + /// + /// Otherwise, return the [`Constructor`] partial variant corresponding to + /// `constructor`. + /// + /// [`Type`]: crate::Type + /// [`ctx.module`]: ExpressionContext::module + fn constructor<'out>( + &mut self, + constructor: &ast::ConstructorType<'source>, + ctx: &mut ExpressionContext<'source, '_, 'out>, + ) -> Result<Constructor<Handle<crate::Type>>, Error<'source>> { + let handle = match *constructor { + ast::ConstructorType::Scalar(scalar) => { + let ty = ctx.ensure_type_exists(scalar.to_inner_scalar()); + Constructor::Type(ty) + } + ast::ConstructorType::PartialVector { size } => Constructor::PartialVector { size }, + ast::ConstructorType::Vector { size, scalar } => { + let ty = ctx.ensure_type_exists(scalar.to_inner_vector(size)); + Constructor::Type(ty) + } + ast::ConstructorType::PartialMatrix { columns, rows } => { + Constructor::PartialMatrix { columns, rows } + } + ast::ConstructorType::Matrix { + rows, + columns, + width, + } => { + let ty = ctx.ensure_type_exists(crate::TypeInner::Matrix { + columns, + rows, + scalar: crate::Scalar::float(width), + }); + Constructor::Type(ty) + } + ast::ConstructorType::PartialArray => Constructor::PartialArray, + ast::ConstructorType::Array { base, size } => { + let base = self.resolve_ast_type(base, &mut ctx.as_global())?; + let size = self.array_size(size, &mut ctx.as_global())?; + + self.layouter.update(ctx.module.to_ctx()).unwrap(); + let stride = self.layouter[base].to_stride(); + + let ty = ctx.ensure_type_exists(crate::TypeInner::Array { base, size, stride }); + Constructor::Type(ty) + } + ast::ConstructorType::Type(ty) => Constructor::Type(ty), + }; + + Ok(handle) + } +} |