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Quelle mod.rs
Sprache: unbekannt
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use std::num::NonZeroU32;
use crate::front::wgsl::error::{Error, ExpectedToken, InvalidAssignmentType};
use crate::front::wgsl::index::Index;
use crate::front::wgsl::parse::number::Number;
use crate::front::wgsl::parse::{ast, conv};
use crate::front::Typifier;
use crate::proc::{
ensure_block_returns, Alignment, ConstantEvaluator, Emitter, Layouter, ResolveContext,
};
use crate::{Arena, FastHashMap, FastIndexMap, Handle, Span};
mod construction;
mod conversion;
/// Resolves the inner type of a given expression.
///
/// Expects a &mut [`ExpressionContext`] and a [`Handle<Expression>`].
///
/// Returns a &[`crate::TypeInner`].
///
/// Ideally, we would simply have a function that takes a `&mut ExpressionContext`
/// and returns a `&TypeResolution`. Unfortunately, this leads the borrow checker
/// to conclude that the mutable borrow lasts for as long as we are using the
/// `&TypeResolution`, so we can't use the `ExpressionContext` for anything else -
/// like, say, resolving another operand's type. Using a macro that expands to
/// two separate calls, only the first of which needs a `&mut`,
/// lets the borrow checker see that the mutable borrow is over.
macro_rules! resolve_inner {
($ctx:ident, $expr:expr) => {{
$ctx.grow_types($expr)?;
$ctx.typifier()[$expr].inner_with(&$ctx.module.types)
}};
}
pub(super) use resolve_inner;
/// Resolves the inner types of two given expressions.
///
/// Expects a &mut [`ExpressionContext`] and two [`Handle<Expression>`]s.
///
/// Returns a tuple containing two &[`crate::TypeInner`].
///
/// See the documentation of [`resolve_inner!`] for why this macro is necessary.
macro_rules! resolve_inner_binary {
($ctx:ident, $left:expr, $right:expr) => {{
$ctx.grow_types($left)?;
$ctx.grow_types($right)?;
(
$ctx.typifier()[$left].inner_with(&$ctx.module.types),
$ctx.typifier()[$right].inner_with(&$ctx.module.types),
)
}};
}
/// Resolves the type of a given expression.
///
/// Expects a &mut [`ExpressionContext`] and a [`Handle<Expression>`].
///
/// Returns a &[`TypeResolution`].
///
/// See the documentation of [`resolve_inner!`] for why this macro is necessary.
///
/// [`TypeResolution`]: crate::proc::TypeResolution
macro_rules! resolve {
($ctx:ident, $expr:expr) => {{
$ctx.grow_types($expr)?;
&$ctx.typifier()[$expr]
}};
}
pub(super) use resolve;
/// State for constructing a `crate::Module`.
pub struct GlobalContext<'source, 'temp, 'out> {
/// The `TranslationUnit`'s expressions arena.
ast_expressions: &'temp Arena<ast::Expression<'source>>,
/// The `TranslationUnit`'s types arena.
types: &'temp Arena<ast::Type<'source>>,
// Naga IR values.
/// The map from the names of module-scope declarations to the Naga IR
/// `Handle`s we have built for them, owned by `Lowerer::lower`.
globals: &'temp mut FastHashMap<&'source str, LoweredGlobalDecl>,
/// The module we're constructing.
module: &'out mut crate::Module,
const_typifier: &'temp mut Typifier,
global_expression_kind_tracker: &'temp mut crate::proc::ExpressionKindTracker,
}
impl<'source> GlobalContext<'source, '_, '_> {
fn as_const(&mut self) -> ExpressionContext<'source, '_, '_> {
ExpressionContext {
ast_expressions: self.ast_expressions,
globals: self.globals,
types: self.types,
module: self.module,
const_typifier: self.const_typifier,
expr_type: ExpressionContextType::Constant(None),
global_expression_kind_tracker: self.global_expression_kind_tracker,
}
}
fn as_override(&mut self) -> ExpressionContext<'source, '_, '_> {
ExpressionContext {
ast_expressions: self.ast_expressions,
globals: self.globals,
types: self.types,
module: self.module,
const_typifier: self.const_typifier,
expr_type: ExpressionContextType::Override,
global_expression_kind_tracker: self.global_expression_kind_tracker,
}
}
fn ensure_type_exists(
&mut self,
name: Option<String>,
inner: crate::TypeInner,
) -> Handle<crate::Type> {
self.module
.types
.insert(crate::Type { inner, name }, Span::UNDEFINED)
}
}
/// State for lowering a statement within a function.
pub struct StatementContext<'source, 'temp, 'out> {
// WGSL AST values.
/// A reference to [`TranslationUnit::expressions`] for the translation unit
/// we're lowering.
///
/// [`TranslationUnit::expressions`]: ast::TranslationUnit::expressions
ast_expressions: &'temp Arena<ast::Expression<'source>>,
/// A reference to [`TranslationUnit::types`] for the translation unit
/// we're lowering.
///
/// [`TranslationUnit::types`]: ast::TranslationUnit::types
types: &'temp Arena<ast::Type<'source>>,
// Naga IR values.
/// The map from the names of module-scope declarations to the Naga IR
/// `Handle`s we have built for them, owned by `Lowerer::lower`.
globals: &'temp mut FastHashMap<&'source str, LoweredGlobalDecl>,
/// A map from each `ast::Local` handle to the Naga expression
/// we've built for it:
///
/// - WGSL function arguments become Naga [`FunctionArgument`] expressions.
///
/// - WGSL `var` declarations become Naga [`LocalVariable`] expressions.
///
/// - WGSL `let` declararations become arbitrary Naga expressions.
///
/// This always borrows the `local_table` local variable in
/// [`Lowerer::function`].
///
/// [`LocalVariable`]: crate::Expression::LocalVariable
/// [`FunctionArgument`]: crate::Expression::FunctionArgument
local_table:
&'temp mut FastHashMap<Handle<ast::Local>, Declared<Typed<Handle<crate::Expression>>>>,
const_typifier: &'temp mut Typifier,
typifier: &'temp mut Typifier,
function: &'out mut crate::Function,
/// Stores the names of expressions that are assigned in `let` statement
/// Also stores the spans of the names, for use in errors.
named_expressions: &'out mut FastIndexMap<Handle<crate::Expression>, (String, Span)>,
module: &'out mut crate::Module,
/// Which `Expression`s in `self.naga_expressions` are const expressions, in
/// the WGSL sense.
///
/// According to the WGSL spec, a const expression must not refer to any
/// `let` declarations, even if those declarations' initializers are
/// themselves const expressions. So this tracker is not simply concerned
/// with the form of the expressions; it is also tracking whether WGSL says
/// we should consider them to be const. See the use of `force_non_const` in
/// the code for lowering `let` bindings.
local_expression_kind_tracker: &'temp mut crate::proc::ExpressionKindTracker,
global_expression_kind_tracker: &'temp mut crate::proc::ExpressionKindTracker,
}
impl<'a, 'temp> StatementContext<'a, 'temp, '_> {
fn as_const<'t>(
&'t mut self,
block: &'t mut crate::Block,
emitter: &'t mut Emitter,
) -> ExpressionContext<'a, 't, 't>
where
'temp: 't,
{
ExpressionContext {
globals: self.globals,
types: self.types,
ast_expressions: self.ast_expressions,
const_typifier: self.const_typifier,
global_expression_kind_tracker: self.global_expression_kind_tracker,
module: self.module,
expr_type: ExpressionContextType::Constant(Some(LocalExpressionContext {
local_table: self.local_table,
function: self.function,
block,
emitter,
typifier: self.typifier,
local_expression_kind_tracker: self.local_expression_kind_tracker,
})),
}
}
fn as_expression<'t>(
&'t mut self,
block: &'t mut crate::Block,
emitter: &'t mut Emitter,
) -> ExpressionContext<'a, 't, 't>
where
'temp: 't,
{
ExpressionContext {
globals: self.globals,
types: self.types,
ast_expressions: self.ast_expressions,
const_typifier: self.const_typifier,
global_expression_kind_tracker: self.global_expression_kind_tracker,
module: self.module,
expr_type: ExpressionContextType::Runtime(LocalExpressionContext {
local_table: self.local_table,
function: self.function,
block,
emitter,
typifier: self.typifier,
local_expression_kind_tracker: self.local_expression_kind_tracker,
}),
}
}
fn as_global(&mut self) -> GlobalContext<'a, '_, '_> {
GlobalContext {
ast_expressions: self.ast_expressions,
globals: self.globals,
types: self.types,
module: self.module,
const_typifier: self.const_typifier,
global_expression_kind_tracker: self.global_expression_kind_tracker,
}
}
fn invalid_assignment_type(&self, expr: Handle<crate::Expression>) -> InvalidAssignmentType {
if let Some(&(_, span)) = self.named_expressions.get(&expr) {
InvalidAssignmentType::ImmutableBinding(span)
} else {
match self.function.expressions[expr] {
crate::Expression::Swizzle { .. } => InvalidAssignmentType::Swizzle,
crate::Expression::Access { base, .. } => self.invalid_assignment_type(base),
crate::Expression::AccessIndex { base, .. } => self.invalid_assignment_type(base),
_ => InvalidAssignmentType::Other,
}
}
}
}
pub struct LocalExpressionContext<'temp, 'out> {
/// A map from [`ast::Local`] handles to the Naga expressions we've built for them.
///
/// This is always [`StatementContext::local_table`] for the
/// enclosing statement; see that documentation for details.
local_table: &'temp FastHashMap<Handle<ast::Local>, Declared<Typed<Handle<crate::Expression>>>>,
function: &'out mut crate::Function,
block: &'temp mut crate::Block,
emitter: &'temp mut Emitter,
typifier: &'temp mut Typifier,
/// Which `Expression`s in `self.naga_expressions` are const expressions, in
/// the WGSL sense.
///
/// See [`StatementContext::local_expression_kind_tracker`] for details.
local_expression_kind_tracker: &'temp mut crate::proc::ExpressionKindTracker,
}
/// The type of Naga IR expression we are lowering an [`ast::Expression`] to.
pub enum ExpressionContextType<'temp, 'out> {
/// We are lowering to an arbitrary runtime expression, to be
/// included in a function's body.
///
/// The given [`LocalExpressionContext`] holds information about local
/// variables, arguments, and other definitions available only to runtime
/// expressions, not constant or override expressions.
Runtime(LocalExpressionContext<'temp, 'out>),
/// We are lowering to a constant expression, to be included in the module's
/// constant expression arena.
///
/// Everything global constant expressions are allowed to refer to is
/// available in the [`ExpressionContext`], but local constant expressions can
/// also refer to other
Constant(Option<LocalExpressionContext<'temp, 'out>>),
/// We are lowering to an override expression, to be included in the module's
/// constant expression arena.
///
/// Everything override expressions are allowed to refer to is
/// available in the [`ExpressionContext`], so this variant
/// carries no further information.
Override,
}
/// State for lowering an [`ast::Expression`] to Naga IR.
///
/// [`ExpressionContext`]s come in two kinds, distinguished by
/// the value of the [`expr_type`] field:
///
/// - A [`Runtime`] context contributes [`naga::Expression`]s to a [`naga::Function`]'s
/// runtime expression arena.
///
/// - A [`Constant`] context contributes [`naga::Expression`]s to a [`naga::Module`]'s
/// constant expression arena.
///
/// [`ExpressionContext`]s are constructed in restricted ways:
///
/// - To get a [`Runtime`] [`ExpressionContext`], call
/// [`StatementContext::as_expression`].
///
/// - To get a [`Constant`] [`ExpressionContext`], call
/// [`GlobalContext::as_const`].
///
/// - You can demote a [`Runtime`] context to a [`Constant`] context
/// by calling [`as_const`], but there's no way to go in the other
/// direction, producing a runtime context from a constant one. This
/// is because runtime expressions can refer to constant
/// expressions, via [`Expression::Constant`], but constant
/// expressions can't refer to a function's expressions.
///
/// Not to be confused with `wgsl::parse::ExpressionContext`, which is
/// for parsing the `ast::Expression` in the first place.
///
/// [`expr_type`]: ExpressionContext::expr_type
/// [`Runtime`]: ExpressionContextType::Runtime
/// [`naga::Expression`]: crate::Expression
/// [`naga::Function`]: crate::Function
/// [`Constant`]: ExpressionContextType::Constant
/// [`naga::Module`]: crate::Module
/// [`as_const`]: ExpressionContext::as_const
/// [`Expression::Constant`]: crate::Expression::Constant
pub struct ExpressionContext<'source, 'temp, 'out> {
// WGSL AST values.
ast_expressions: &'temp Arena<ast::Expression<'source>>,
types: &'temp Arena<ast::Type<'source>>,
// Naga IR values.
/// The map from the names of module-scope declarations to the Naga IR
/// `Handle`s we have built for them, owned by `Lowerer::lower`.
globals: &'temp mut FastHashMap<&'source str, LoweredGlobalDecl>,
/// The IR [`Module`] we're constructing.
///
/// [`Module`]: crate::Module
module: &'out mut crate::Module,
/// Type judgments for [`module::global_expressions`].
///
/// [`module::global_expressions`]: crate::Module::global_expressions
const_typifier: &'temp mut Typifier,
global_expression_kind_tracker: &'temp mut crate::proc::ExpressionKindTracker,
/// Whether we are lowering a constant expression or a general
/// runtime expression, and the data needed in each case.
expr_type: ExpressionContextType<'temp, 'out>,
}
impl<'source, 'temp, 'out> ExpressionContext<'source, 'temp, 'out> {
fn as_const(&mut self) -> ExpressionContext<'source, '_, '_> {
ExpressionContext {
globals: self.globals,
types: self.types,
ast_expressions: self.ast_expressions,
const_typifier: self.const_typifier,
module: self.module,
expr_type: ExpressionContextType::Constant(None),
global_expression_kind_tracker: self.global_expression_kind_tracker,
}
}
fn as_global(&mut self) -> GlobalContext<'source, '_, '_> {
GlobalContext {
ast_expressions: self.ast_expressions,
globals: self.globals,
types: self.types,
module: self.module,
const_typifier: self.const_typifier,
global_expression_kind_tracker: self.global_expression_kind_tracker,
}
}
fn as_const_evaluator(&mut self) -> ConstantEvaluator {
match self.expr_type {
ExpressionContextType::Runtime(ref mut rctx) => ConstantEvaluator::for_wgsl_function(
self.module,
&mut rctx.function.expressions,
rctx.local_expression_kind_tracker,
rctx.emitter,
rctx.block,
false,
),
ExpressionContextType::Constant(Some(ref mut rctx)) => {
ConstantEvaluator::for_wgsl_function(
self.module,
&mut rctx.function.expressions,
rctx.local_expression_kind_tracker,
rctx.emitter,
rctx.block,
true,
)
}
ExpressionContextType::Constant(None) => ConstantEvaluator::for_wgsl_module(
self.module,
self.global_expression_kind_tracker,
false,
),
ExpressionContextType::Override => ConstantEvaluator::for_wgsl_module(
self.module,
self.global_expression_kind_tracker,
true,
),
}
}
fn append_expression(
&mut self,
expr: crate::Expression,
span: Span,
) -> Result<Handle<crate::Expression>, Error<'source>> {
let mut eval = self.as_const_evaluator();
eval.try_eval_and_append(expr, span)
.map_err(|e| Error::ConstantEvaluatorError(e.into(), span))
}
fn const_access(&self, handle: Handle<crate::Expression>) -> Option<u32> {
match self.expr_type {
ExpressionContextType::Runtime(ref ctx) => {
if !ctx.local_expression_kind_tracker.is_const(handle) {
return None;
}
self.module
.to_ctx()
.eval_expr_to_u32_from(handle, &ctx.function.expressions)
.ok()
}
ExpressionContextType::Constant(Some(ref ctx)) => {
assert!(ctx.local_expression_kind_tracker.is_const(handle));
self.module
.to_ctx()
.eval_expr_to_u32_from(handle, &ctx.function.expressions)
.ok()
}
ExpressionContextType::Constant(None) => {
self.module.to_ctx().eval_expr_to_u32(handle).ok()
}
ExpressionContextType::Override => None,
}
}
fn get_expression_span(&self, handle: Handle<crate::Expression>) -> Span {
match self.expr_type {
ExpressionContextType::Runtime(ref ctx)
| ExpressionContextType::Constant(Some(ref ctx)) => {
ctx.function.expressions.get_span(handle)
}
ExpressionContextType::Constant(None) | ExpressionContextType::Override => {
self.module.global_expressions.get_span(handle)
}
}
}
fn typifier(&self) -> &Typifier {
match self.expr_type {
ExpressionContextType::Runtime(ref ctx)
| ExpressionContextType::Constant(Some(ref ctx)) => ctx.typifier,
ExpressionContextType::Constant(None) | ExpressionContextType::Override => {
self.const_typifier
}
}
}
fn local(
&mut self,
local: &Handle<ast::Local>,
span: Span,
) -> Result<Typed<Handle<crate::Expression>>, Error<'source>> {
match self.expr_type {
ExpressionContextType::Runtime(ref ctx) => Ok(ctx.local_table[local].runtime()),
ExpressionContextType::Constant(Some(ref ctx)) => ctx.local_table[local]
.const_time()
.ok_or(Error::UnexpectedOperationInConstContext(span)),
_ => Err(Error::UnexpectedOperationInConstContext(span)),
}
}
fn runtime_expression_ctx(
&mut self,
span: Span,
) -> Result<&mut LocalExpressionContext<'temp, 'out>, Error<'source>> {
match self.expr_type {
ExpressionContextType::Runtime(ref mut ctx) => Ok(ctx),
ExpressionContextType::Constant(_) | ExpressionContextType::Override => {
Err(Error::UnexpectedOperationInConstContext(span))
}
}
}
fn gather_component(
&mut self,
expr: Handle<crate::Expression>,
component_span: Span,
gather_span: Span,
) -> Result<crate::SwizzleComponent, Error<'source>> {
match self.expr_type {
ExpressionContextType::Runtime(ref rctx) => {
if !rctx.local_expression_kind_tracker.is_const(expr) {
return Err(Error::ExpectedConstExprConcreteIntegerScalar(
component_span,
));
}
let index = self
.module
.to_ctx()
.eval_expr_to_u32_from(expr, &rctx.function.expressions)
.map_err(|err| match err {
crate::proc::U32EvalError::NonConst => {
Error::ExpectedConstExprConcreteIntegerScalar(component_span)
}
crate::proc::U32EvalError::Negative => {
Error::ExpectedNonNegative(component_span)
}
})?;
crate::SwizzleComponent::XYZW
.get(index as usize)
.copied()
.ok_or(Error::InvalidGatherComponent(component_span))
}
// This means a `gather` operation appeared in a constant expression.
// This error refers to the `gather` itself, not its "component" argument.
ExpressionContextType::Constant(_) | ExpressionContextType::Override => {
Err(Error::UnexpectedOperationInConstContext(gather_span))
}
}
}
/// Determine the type of `handle`, and add it to the module's arena.
///
/// If you just need a `TypeInner` for `handle`'s type, use the
/// [`resolve_inner!`] macro instead. This function
/// should only be used when the type of `handle` needs to appear
/// in the module's final `Arena<Type>`, for example, if you're
/// creating a [`LocalVariable`] whose type is inferred from its
/// initializer.
///
/// [`LocalVariable`]: crate::LocalVariable
fn register_type(
&mut self,
handle: Handle<crate::Expression>,
) -> Result<Handle<crate::Type>, Error<'source>> {
self.grow_types(handle)?;
// This is equivalent to calling ExpressionContext::typifier(),
// except that this lets the borrow checker see that it's okay
// to also borrow self.module.types mutably below.
let typifier = match self.expr_type {
ExpressionContextType::Runtime(ref ctx)
| ExpressionContextType::Constant(Some(ref ctx)) => ctx.typifier,
ExpressionContextType::Constant(None) | ExpressionContextType::Override => {
&*self.const_typifier
}
};
Ok(typifier.register_type(handle, &mut self.module.types))
}
/// Resolve the types of all expressions up through `handle`.
///
/// Ensure that [`self.typifier`] has a [`TypeResolution`] for
/// every expression in [`self.function.expressions`].
///
/// This does not add types to any arena. The [`Typifier`]
/// documentation explains the steps we take to avoid filling
/// arenas with intermediate types.
///
/// This function takes `&mut self`, so it can't conveniently
/// return a shared reference to the resulting `TypeResolution`:
/// the shared reference would extend the mutable borrow, and you
/// wouldn't be able to use `self` for anything else. Instead, you
/// should use [`register_type`] or one of [`resolve!`],
/// [`resolve_inner!`] or [`resolve_inner_binary!`].
///
/// [`self.typifier`]: ExpressionContext::typifier
/// [`TypeResolution`]: crate::proc::TypeResolution
/// [`register_type`]: Self::register_type
/// [`Typifier`]: Typifier
fn grow_types(
&mut self,
handle: Handle<crate::Expression>,
) -> Result<&mut Self, Error<'source>> {
let empty_arena = Arena::new();
let resolve_ctx;
let typifier;
let expressions;
match self.expr_type {
ExpressionContextType::Runtime(ref mut ctx)
| ExpressionContextType::Constant(Some(ref mut ctx)) => {
resolve_ctx = ResolveContext::with_locals(
self.module,
&ctx.function.local_variables,
&ctx.function.arguments,
);
typifier = &mut *ctx.typifier;
expressions = &ctx.function.expressions;
}
ExpressionContextType::Constant(None) | ExpressionContextType::Override => {
resolve_ctx = ResolveContext::with_locals(self.module, &empty_arena, &[]);
typifier = self.const_typifier;
expressions = &self.module.global_expressions;
}
};
typifier
.grow(handle, expressions, &resolve_ctx)
.map_err(Error::InvalidResolve)?;
Ok(self)
}
fn image_data(
&mut self,
image: Handle<crate::Expression>,
span: Span,
) -> Result<(crate::ImageClass, bool), Error<'source>> {
match *resolve_inner!(self, image) {
crate::TypeInner::Image { class, arrayed, .. } => Ok((class, arrayed)),
_ => Err(Error::BadTexture(span)),
}
}
fn prepare_args<'b>(
&mut self,
args: &'b [Handle<ast::Expression<'source>>],
min_args: u32,
span: Span,
) -> ArgumentContext<'b, 'source> {
ArgumentContext {
args: args.iter(),
min_args,
args_used: 0,
total_args: args.len() as u32,
span,
}
}
/// Insert splats, if needed by the non-'*' operations.
///
/// See the "Binary arithmetic expressions with mixed scalar and vector operands"
/// table in the WebGPU Shading Language specification for relevant operators.
///
/// Multiply is not handled here as backends are expected to handle vec*scalar
/// operations, so inserting splats into the IR increases size needlessly.
fn binary_op_splat(
&mut self,
op: crate::BinaryOperator,
left: &mut Handle<crate::Expression>,
right: &mut Handle<crate::Expression>,
) -> Result<(), Error<'source>> {
if matches!(
op,
crate::BinaryOperator::Add
| crate::BinaryOperator::Subtract
| crate::BinaryOperator::Divide
| crate::BinaryOperator::Modulo
) {
match resolve_inner_binary!(self, *left, *right) {
(&crate::TypeInner::Vector { size, .. }, &crate::TypeInner::Scalar { .. }) => {
*right = self.append_expression(
crate::Expression::Splat {
size,
value: *right,
},
self.get_expression_span(*right),
)?;
}
(&crate::TypeInner::Scalar { .. }, &crate::TypeInner::Vector { size, .. }) => {
*left = self.append_expression(
crate::Expression::Splat { size, value: *left },
self.get_expression_span(*left),
)?;
}
_ => {}
}
}
Ok(())
}
/// Add a single expression to the expression table that is not covered by `self.emitter`.
///
/// This is useful for `CallResult` and `AtomicResult` expressions, which should not be covered by
/// `Emit` statements.
fn interrupt_emitter(
&mut self,
expression: crate::Expression,
span: Span,
) -> Result<Handle<crate::Expression>, Error<'source>> {
match self.expr_type {
ExpressionContextType::Runtime(ref mut rctx)
| ExpressionContextType::Constant(Some(ref mut rctx)) => {
rctx.block
.extend(rctx.emitter.finish(&rctx.function.expressions));
}
ExpressionContextType::Constant(None) | ExpressionContextType::Override => {}
}
let result = self.append_expression(expression, span);
match self.expr_type {
ExpressionContextType::Runtime(ref mut rctx)
| ExpressionContextType::Constant(Some(ref mut rctx)) => {
rctx.emitter.start(&rctx.function.expressions);
}
ExpressionContextType::Constant(None) | ExpressionContextType::Override => {}
}
result
}
/// Apply the WGSL Load Rule to `expr`.
///
/// If `expr` is has type `ref<SC, T, A>`, perform a load to produce a value of type
/// `T`. Otherwise, return `expr` unchanged.
fn apply_load_rule(
&mut self,
expr: Typed<Handle<crate::Expression>>,
) -> Result<Handle<crate::Expression>, Error<'source>> {
match expr {
Typed::Reference(pointer) => {
let load = crate::Expression::Load { pointer };
let span = self.get_expression_span(pointer);
self.append_expression(load, span)
}
Typed::Plain(handle) => Ok(handle),
}
}
fn ensure_type_exists(&mut self, inner: crate::TypeInner) -> Handle<crate::Type> {
self.as_global().ensure_type_exists(None, inner)
}
}
struct ArgumentContext<'ctx, 'source> {
args: std::slice::Iter<'ctx, Handle<ast::Expression<'source>>>,
min_args: u32,
args_used: u32,
total_args: u32,
span: Span,
}
impl<'source> ArgumentContext<'_, 'source> {
pub fn finish(self) -> Result<(), Error<'source>> {
if self.args.len() == 0 {
Ok(())
} else {
Err(Error::WrongArgumentCount {
found: self.total_args,
expected: self.min_args..self.args_used + 1,
span: self.span,
})
}
}
pub fn next(&mut self) -> Result<Handle<ast::Expression<'source>>, Error<'source>> {
match self.args.next().copied() {
Some(arg) => {
self.args_used += 1;
Ok(arg)
}
None => Err(Error::WrongArgumentCount {
found: self.total_args,
expected: self.min_args..self.args_used + 1,
span: self.span,
}),
}
}
}
#[derive(Debug, Copy, Clone)]
enum Declared<T> {
/// Value declared as const
Const(T),
/// Value declared as non-const
Runtime(T),
}
impl<T> Declared<T> {
fn runtime(self) -> T {
match self {
Declared::Const(t) | Declared::Runtime(t) => t,
}
}
fn const_time(self) -> Option<T> {
match self {
Declared::Const(t) => Some(t),
Declared::Runtime(_) => None,
}
}
}
/// WGSL type annotations on expressions, types, values, etc.
///
/// Naga and WGSL types are very close, but Naga lacks WGSL's `ref` types, which
/// we need to know to apply the Load Rule. This enum carries some WGSL or Naga
/// datum along with enough information to determine its corresponding WGSL
/// type.
///
/// The `T` type parameter can be any expression-like thing:
///
/// - `Typed<Handle<crate::Type>>` can represent a full WGSL type. For example,
/// given some Naga `Pointer` type `ptr`, a WGSL reference type is a
/// `Typed::Reference(ptr)` whereas a WGSL pointer type is a
/// `Typed::Plain(ptr)`.
///
/// - `Typed<crate::Expression>` or `Typed<Handle<crate::Expression>>` can
/// represent references similarly.
///
/// Use the `map` and `try_map` methods to convert from one expression
/// representation to another.
///
/// [`Expression`]: crate::Expression
#[derive(Debug, Copy, Clone)]
enum Typed<T> {
/// A WGSL reference.
Reference(T),
/// A WGSL plain type.
Plain(T),
}
impl<T> Typed<T> {
fn map<U>(self, mut f: impl FnMut(T) -> U) -> Typed<U> {
match self {
Self::Reference(v) => Typed::Reference(f(v)),
Self::Plain(v) => Typed::Plain(f(v)),
}
}
fn try_map<U, E>(self, mut f: impl FnMut(T) -> Result<U, E>) -> Result<Typed<U>, E> {
Ok(match self {
Self::Reference(expr) => Typed::Reference(f(expr)?),
Self::Plain(expr) => Typed::Plain(f(expr)?),
})
}
}
/// A single vector component or swizzle.
///
/// This represents the things that can appear after the `.` in a vector access
/// expression: either a single component name, or a series of them,
/// representing a swizzle.
enum Components {
Single(u32),
Swizzle {
size: crate::VectorSize,
pattern: [crate::SwizzleComponent; 4],
},
}
impl Components {
const fn letter_component(letter: char) -> Option<crate::SwizzleComponent> {
use crate::SwizzleComponent as Sc;
match letter {
'x' | 'r' => Some(Sc::X),
'y' | 'g' => Some(Sc::Y),
'z' | 'b' => Some(Sc::Z),
'w' | 'a' => Some(Sc::W),
_ => None,
}
}
fn single_component(name: &str, name_span: Span) -> Result<u32, Error> {
let ch = name.chars().next().ok_or(Error::BadAccessor(name_span))?;
match Self::letter_component(ch) {
Some(sc) => Ok(sc as u32),
None => Err(Error::BadAccessor(name_span)),
}
}
/// Construct a `Components` value from a 'member' name, like `"wzy"` or `"x"`.
///
/// Use `name_span` for reporting errors in parsing the component string.
fn new(name: &str, name_span: Span) -> Result<Self, Error> {
let size = match name.len() {
1 => return Ok(Components::Single(Self::single_component(name, name_span)?)),
2 => crate::VectorSize::Bi,
3 => crate::VectorSize::Tri,
4 => crate::VectorSize::Quad,
_ => return Err(Error::BadAccessor(name_span)),
};
let mut pattern = [crate::SwizzleComponent::X; 4];
for (comp, ch) in pattern.iter_mut().zip(name.chars()) {
*comp = Self::letter_component(ch).ok_or(Error::BadAccessor(name_span))?;
}
if name.chars().all(|c| matches!(c, 'x' | 'y' | 'z' | 'w'))
|| name.chars().all(|c| matches!(c, 'r' | 'g' | 'b' | 'a'))
{
Ok(Components::Swizzle { size, pattern })
} else {
Err(Error::BadAccessor(name_span))
}
}
}
/// An `ast::GlobalDecl` for which we have built the Naga IR equivalent.
enum LoweredGlobalDecl {
Function(Handle<crate::Function>),
Var(Handle<crate::GlobalVariable>),
Const(Handle<crate::Constant>),
Override(Handle<crate::Override>),
Type(Handle<crate::Type>),
EntryPoint,
}
enum Texture {
Gather,
GatherCompare,
Sample,
SampleBias,
SampleCompare,
SampleCompareLevel,
SampleGrad,
SampleLevel,
// SampleBaseClampToEdge,
}
impl Texture {
pub fn map(word: &str) -> Option<Self> {
Some(match word {
"textureGather" => Self::Gather,
"textureGatherCompare" => Self::GatherCompare,
"textureSample" => Self::Sample,
"textureSampleBias" => Self::SampleBias,
"textureSampleCompare" => Self::SampleCompare,
"textureSampleCompareLevel" => Self::SampleCompareLevel,
"textureSampleGrad" => Self::SampleGrad,
"textureSampleLevel" => Self::SampleLevel,
// "textureSampleBaseClampToEdge" => Some(Self::SampleBaseClampToEdge),
_ => return None,
})
}
pub const fn min_argument_count(&self) -> u32 {
match *self {
Self::Gather => 3,
Self::GatherCompare => 4,
Self::Sample => 3,
Self::SampleBias => 5,
Self::SampleCompare => 5,
Self::SampleCompareLevel => 5,
Self::SampleGrad => 6,
Self::SampleLevel => 5,
// Self::SampleBaseClampToEdge => 3,
}
}
}
enum SubgroupGather {
BroadcastFirst,
Broadcast,
Shuffle,
ShuffleDown,
ShuffleUp,
ShuffleXor,
}
impl SubgroupGather {
pub fn map(word: &str) -> Option<Self> {
Some(match word {
"subgroupBroadcastFirst" => Self::BroadcastFirst,
"subgroupBroadcast" => Self::Broadcast,
"subgroupShuffle" => Self::Shuffle,
"subgroupShuffleDown" => Self::ShuffleDown,
"subgroupShuffleUp" => Self::ShuffleUp,
"subgroupShuffleXor" => Self::ShuffleXor,
_ => return None,
})
}
}
pub struct Lowerer<'source, 'temp> {
index: &'temp Index<'source>,
layouter: Layouter,
}
impl<'source, 'temp> Lowerer<'source, 'temp> {
pub fn new(index: &'temp Index<'source>) -> Self {
Self {
index,
layouter: Layouter::default(),
}
}
pub fn lower(
&mut self,
tu: &'temp ast::TranslationUnit<'source>,
) -> Result<crate::Module, Error<'source>> {
let mut module = crate::Module {
diagnostic_filters: tu.diagnostic_filters.clone(),
diagnostic_filter_leaf: tu.diagnostic_filter_leaf,
..Default::default()
};
let mut ctx = GlobalContext {
ast_expressions: &tu.expressions,
globals: &mut FastHashMap::default(),
types: &tu.types,
module: &mut module,
const_typifier: &mut Typifier::new(),
global_expression_kind_tracker: &mut crate::proc::ExpressionKindTracker::new(),
};
for decl_handle in self.index.visit_ordered() {
let span = tu.decls.get_span(decl_handle);
let decl = &tu.decls[decl_handle];
match decl.kind {
ast::GlobalDeclKind::Fn(ref f) => {
let lowered_decl = self.function(f, span, &mut ctx)?;
ctx.globals.insert(f.name.name, lowered_decl);
}
ast::GlobalDeclKind::Var(ref v) => {
let explicit_ty =
v.ty.map(|ast| self.resolve_ast_type(ast, &mut ctx))
.transpose()?;
let mut ectx = ctx.as_override();
let ty;
let initializer;
match (v.init, explicit_ty) {
(Some(init), Some(explicit_ty)) => {
let init = self.expression_for_abstract(init, &mut ectx)?;
let ty_res = crate::proc::TypeResolution::Handle(explicit_ty);
let init = ectx
.try_automatic_conversions(init, &ty_res, v.name.span)
.map_err(|error| match error {
Error::AutoConversion(e) => Error::InitializationTypeMismatch {
name: v.name.span,
expected: e.dest_type,
got: e.source_type,
},
other => other,
})?;
ty = explicit_ty;
initializer = Some(init);
}
(Some(init), None) => {
let concretized = self.expression(init, &mut ectx)?;
ty = ectx.register_type(concretized)?;
initializer = Some(concretized);
}
(None, Some(explicit_ty)) => {
ty = explicit_ty;
initializer = None;
}
(None, None) => return Err(Error::DeclMissingTypeAndInit(v.name.span)),
}
let binding = if let Some(ref binding) = v.binding {
Some(crate::ResourceBinding {
group: self.const_u32(binding.group, &mut ctx.as_const())?.0,
binding: self.const_u32(binding.binding, &mut ctx.as_const())?.0,
})
} else {
None
};
let handle = ctx.module.global_variables.append(
crate::GlobalVariable {
name: Some(v.name.name.to_string()),
space: v.space,
binding,
ty,
init: initializer,
},
span,
);
ctx.globals
.insert(v.name.name, LoweredGlobalDecl::Var(handle));
}
ast::GlobalDeclKind::Const(ref c) => {
let mut ectx = ctx.as_const();
let mut init = self.expression_for_abstract(c.init, &mut ectx)?;
let ty;
if let Some(explicit_ty) = c.ty {
let explicit_ty =
self.resolve_ast_type(explicit_ty, &mut ectx.as_global())?;
let explicit_ty_res = crate::proc::TypeResolution::Handle(explicit_ty);
init = ectx
.try_automatic_conversions(init, &explicit_ty_res, c.name.span)
.map_err(|error| match error {
Error::AutoConversion(e) => Error::InitializationTypeMismatch {
name: c.name.span,
expected: e.dest_type,
got: e.source_type,
},
other => other,
})?;
ty = explicit_ty;
} else {
init = ectx.concretize(init)?;
ty = ectx.register_type(init)?;
}
let handle = ctx.module.constants.append(
crate::Constant {
name: Some(c.name.name.to_string()),
ty,
init,
},
span,
);
ctx.globals
.insert(c.name.name, LoweredGlobalDecl::Const(handle));
}
ast::GlobalDeclKind::Override(ref o) => {
let init = o
.init
.map(|init| self.expression(init, &mut ctx.as_override()))
.transpose()?;
let inferred_type = init
.map(|init| ctx.as_const().register_type(init))
.transpose()?;
let explicit_ty =
o.ty.map(|ty| self.resolve_ast_type(ty, &mut ctx))
.transpose()?;
let id =
o.id.map(|id| self.const_u32(id, &mut ctx.as_const()))
.transpose()?;
let id = if let Some((id, id_span)) = id {
Some(
u16::try_from(id)
.map_err(|_| Error::PipelineConstantIDValue(id_span))?,
)
} else {
None
};
let ty = match (explicit_ty, inferred_type) {
(Some(explicit_ty), Some(inferred_type)) => {
if explicit_ty == inferred_type {
explicit_ty
} else {
let gctx = ctx.module.to_ctx();
return Err(Error::InitializationTypeMismatch {
name: o.name.span,
expected: explicit_ty.to_wgsl(&gctx).into(),
got: inferred_type.to_wgsl(&gctx).into(),
});
}
}
(Some(explicit_ty), None) => explicit_ty,
(None, Some(inferred_type)) => inferred_type,
(None, None) => {
return Err(Error::DeclMissingTypeAndInit(o.name.span));
}
};
let handle = ctx.module.overrides.append(
crate::Override {
name: Some(o.name.name.to_string()),
id,
ty,
init,
},
span,
);
ctx.globals
.insert(o.name.name, LoweredGlobalDecl::Override(handle));
}
ast::GlobalDeclKind::Struct(ref s) => {
let handle = self.r#struct(s, span, &mut ctx)?;
ctx.globals
.insert(s.name.name, LoweredGlobalDecl::Type(handle));
}
ast::GlobalDeclKind::Type(ref alias) => {
let ty = self.resolve_named_ast_type(
alias.ty,
Some(alias.name.name.to_string()),
&mut ctx,
)?;
ctx.globals
.insert(alias.name.name, LoweredGlobalDecl::Type(ty));
}
ast::GlobalDeclKind::ConstAssert(condition) => {
let condition = self.expression(condition, &mut ctx.as_const())?;
let span = ctx.module.global_expressions.get_span(condition);
match ctx
.module
.to_ctx()
.eval_expr_to_bool_from(condition, &ctx.module.global_expressions)
{
Some(true) => Ok(()),
Some(false) => Err(Error::ConstAssertFailed(span)),
_ => Err(Error::NotBool(span)),
}?;
}
}
}
// Constant evaluation may leave abstract-typed literals and
// compositions in expression arenas, so we need to compact the module
// to remove unused expressions and types.
crate::compact::compact(&mut module);
Ok(module)
}
fn function(
&mut self,
f: &ast::Function<'source>,
span: Span,
ctx: &mut GlobalContext<'source, '_, '_>,
) -> Result<LoweredGlobalDecl, Error<'source>> {
let mut local_table = FastHashMap::default();
let mut expressions = Arena::new();
let mut named_expressions = FastIndexMap::default();
let mut local_expression_kind_tracker = crate::proc::ExpressionKindTracker::new();
let arguments = f
.arguments
.iter()
.enumerate()
.map(|(i, arg)| -> Result<_, Error<'_>> {
let ty = self.resolve_ast_type(arg.ty, ctx)?;
let expr = expressions
.append(crate::Expression::FunctionArgument(i as u32), arg.name.span);
local_table.insert(arg.handle, Declared::Runtime(Typed::Plain(expr)));
named_expressions.insert(expr, (arg.name.name.to_string(), arg.name.span));
local_expression_kind_tracker.insert(expr, crate::proc::ExpressionKind::Runtime);
Ok(crate::FunctionArgument {
name: Some(arg.name.name.to_string()),
ty,
binding: self.binding(&arg.binding, ty, ctx)?,
})
})
.collect::<Result<Vec<_>, _>>()?;
let result = f
.result
.as_ref()
.map(|res| -> Result<_, Error<'_>> {
let ty = self.resolve_ast_type(res.ty, ctx)?;
Ok(crate::FunctionResult {
ty,
binding: self.binding(&res.binding, ty, ctx)?,
})
})
.transpose()?;
let mut function = crate::Function {
name: Some(f.name.name.to_string()),
arguments,
result,
local_variables: Arena::new(),
expressions,
named_expressions: crate::NamedExpressions::default(),
body: crate::Block::default(),
diagnostic_filter_leaf: f.diagnostic_filter_leaf,
};
let mut typifier = Typifier::default();
let mut stmt_ctx = StatementContext {
local_table: &mut local_table,
globals: ctx.globals,
ast_expressions: ctx.ast_expressions,
const_typifier: ctx.const_typifier,
typifier: &mut typifier,
function: &mut function,
named_expressions: &mut named_expressions,
types: ctx.types,
module: ctx.module,
local_expression_kind_tracker: &mut local_expression_kind_tracker,
global_expression_kind_tracker: ctx.global_expression_kind_tracker,
};
let mut body = self.block(&f.body, false, &mut stmt_ctx)?;
ensure_block_returns(&mut body);
function.body = body;
function.named_expressions = named_expressions
.into_iter()
.map(|(key, (name, _))| (key, name))
.collect();
if let Some(ref entry) = f.entry_point {
let workgroup_size_info = if let Some(workgroup_size) = entry.workgroup_size {
// TODO: replace with try_map once stabilized
let mut workgroup_size_out = [1; 3];
let mut workgroup_size_overrides_out = [None; 3];
for (i, size) in workgroup_size.into_iter().enumerate() {
if let Some(size_expr) = size {
match self.const_u32(size_expr, &mut ctx.as_const()) {
Ok(value) => {
workgroup_size_out[i] = value.0;
}
err => {
if let Err(Error::ConstantEvaluatorError(ref ty, _)) = err {
match **ty {
crate::proc::ConstantEvaluatorError::OverrideExpr => {
workgroup_size_overrides_out[i] =
Some(self.workgroup_size_override(
size_expr,
&mut ctx.as_override(),
)?);
}
_ => {
err?;
}
}
} else {
err?;
}
}
}
}
}
if workgroup_size_overrides_out.iter().all(|x| x.is_none()) {
(workgroup_size_out, None)
} else {
(workgroup_size_out, Some(workgroup_size_overrides_out))
}
} else {
([0; 3], None)
};
let (workgroup_size, workgroup_size_overrides) = workgroup_size_info;
ctx.module.entry_points.push(crate::EntryPoint {
name: f.name.name.to_string(),
stage: entry.stage,
early_depth_test: entry.early_depth_test,
workgroup_size,
workgroup_size_overrides,
function,
});
Ok(LoweredGlobalDecl::EntryPoint)
} else {
let handle = ctx.module.functions.append(function, span);
Ok(LoweredGlobalDecl::Function(handle))
}
}
fn workgroup_size_override(
&mut self,
size_expr: Handle<ast::Expression<'source>>,
ctx: &mut ExpressionContext<'source, '_, '_>,
) -> Result<Handle<crate::Expression>, Error<'source>> {
let span = ctx.ast_expressions.get_span(size_expr);
let expr = self.expression(size_expr, ctx)?;
match resolve_inner!(ctx, expr).scalar_kind().ok_or(0) {
Ok(crate::ScalarKind::Sint) | Ok(crate::ScalarKind::Uint) => Ok(expr),
_ => Err(Error::ExpectedConstExprConcreteIntegerScalar(span)),
}
}
fn block(
&mut self,
b: &ast::Block<'source>,
is_inside_loop: bool,
ctx: &mut StatementContext<'source, '_, '_>,
) -> Result<crate::Block, Error<'source>> {
let mut block = crate::Block::default();
for stmt in b.stmts.iter() {
self.statement(stmt, &mut block, is_inside_loop, ctx)?;
}
Ok(block)
}
fn statement(
&mut self,
stmt: &ast::Statement<'source>,
block: &mut crate::Block,
is_inside_loop: bool,
ctx: &mut StatementContext<'source, '_, '_>,
) -> Result<(), Error<'source>> {
let out = match stmt.kind {
ast::StatementKind::Block(ref block) => {
let block = self.block(block, is_inside_loop, ctx)?;
crate::Statement::Block(block)
}
ast::StatementKind::LocalDecl(ref decl) => match *decl {
ast::LocalDecl::Let(ref l) => {
let mut emitter = Emitter::default();
emitter.start(&ctx.function.expressions);
let value =
self.expression(l.init, &mut ctx.as_expression(block, &mut emitter))?;
// The WGSL spec says that any expression that refers to a
// `let`-bound variable is not a const expression. This
// affects when errors must be reported, so we can't even
// treat suitable `let` bindings as constant as an
// optimization.
ctx.local_expression_kind_tracker.force_non_const(value);
let explicit_ty =
l.ty.map(|ty| self.resolve_ast_type(ty, &mut ctx.as_global()))
.transpose()?;
if let Some(ty) = explicit_ty {
let mut ctx = ctx.as_expression(block, &mut emitter);
let init_ty = ctx.register_type(value)?;
if !ctx.module.types[ty]
.inner
.equivalent(&ctx.module.types[init_ty].inner, &ctx.module.types)
{
let gctx = &ctx.module.to_ctx();
return Err(Error::InitializationTypeMismatch {
name: l.name.span,
expected: ty.to_wgsl(gctx).into(),
got: init_ty.to_wgsl(gctx).into(),
});
}
}
block.extend(emitter.finish(&ctx.function.expressions));
ctx.local_table
.insert(l.handle, Declared::Runtime(Typed::Plain(value)));
ctx.named_expressions
.insert(value, (l.name.name.to_string(), l.name.span));
return Ok(());
}
ast::LocalDecl::Var(ref v) => {
let explicit_ty =
v.ty.map(|ast| self.resolve_ast_type(ast, &mut ctx.as_global()))
.transpose()?;
let mut emitter = Emitter::default();
emitter.start(&ctx.function.expressions);
let mut ectx = ctx.as_expression(block, &mut emitter);
let ty;
let initializer;
match (v.init, explicit_ty) {
(Some(init), Some(explicit_ty)) => {
let init = self.expression_for_abstract(init, &mut ectx)?;
let ty_res = crate::proc::TypeResolution::Handle(explicit_ty);
let init = ectx
.try_automatic_conversions(init, &ty_res, v.name.span)
.map_err(|error| match error {
Error::AutoConversion(e) => Error::InitializationTypeMismatch {
name: v.name.span,
expected: e.dest_type,
got: e.source_type,
},
other => other,
})?;
ty = explicit_ty;
initializer = Some(init);
}
(Some(init), None) => {
let concretized = self.expression(init, &mut ectx)?;
ty = ectx.register_type(concretized)?;
initializer = Some(concretized);
}
(None, Some(explicit_ty)) => {
ty = explicit_ty;
initializer = None;
}
(None, None) => return Err(Error::DeclMissingTypeAndInit(v.name.span)),
}
let (const_initializer, initializer) = {
match initializer {
Some(init) => {
// It's not correct to hoist the initializer up
// to the top of the function if:
// - the initialization is inside a loop, and should
// take place on every iteration, or
// - the initialization is not a constant
// expression, so its value depends on the
// state at the point of initialization.
if is_inside_loop
|| !ctx.local_expression_kind_tracker.is_const_or_override(init)
{
(None, Some(init))
} else {
(Some(init), None)
}
}
None => (None, None),
}
};
let var = ctx.function.local_variables.append(
crate::LocalVariable {
name: Some(v.name.name.to_string()),
ty,
init: const_initializer,
},
stmt.span,
);
let handle = ctx.as_expression(block, &mut emitter).interrupt_emitter(
crate::Expression::LocalVariable(var),
Span::UNDEFINED,
)?;
block.extend(emitter.finish(&ctx.function.expressions));
ctx.local_table
.insert(v.handle, Declared::Runtime(Typed::Reference(handle)));
match initializer {
Some(initializer) => crate::Statement::Store {
pointer: handle,
value: initializer,
},
None => return Ok(()),
}
}
ast::LocalDecl::Const(ref c) => {
let mut emitter = Emitter::default();
emitter.start(&ctx.function.expressions);
let ectx = &mut ctx.as_const(block, &mut emitter);
let mut init = self.expression_for_abstract(c.init, ectx)?;
if let Some(explicit_ty) = c.ty {
let explicit_ty =
self.resolve_ast_type(explicit_ty, &mut ectx.as_global())?;
let explicit_ty_res = crate::proc::TypeResolution::Handle(explicit_ty);
init = ectx
.try_automatic_conversions(init, &explicit_ty_res, c.name.span)
.map_err(|error| match error {
Error::AutoConversion(error) => Error::InitializationTypeMismatch {
name: c.name.span,
expected: error.dest_type,
got: error.source_type,
},
other => other,
})?;
} else {
init = ectx.concretize(init)?;
ectx.register_type(init)?;
}
block.extend(emitter.finish(&ctx.function.expressions));
ctx.local_table
.insert(c.handle, Declared::Const(Typed::Plain(init)));
ctx.named_expressions
.insert(init, (c.name.name.to_string(), c.name.span));
return Ok(());
}
},
ast::StatementKind::If {
condition,
ref accept,
ref reject,
} => {
let mut emitter = Emitter::default();
emitter.start(&ctx.function.expressions);
let condition =
self.expression(condition, &mut ctx.as_expression(block, &mut emitter))?;
block.extend(emitter.finish(&ctx.function.expressions));
let accept = self.block(accept, is_inside_loop, ctx)?;
let reject = self.block(reject, is_inside_loop, ctx)?;
crate::Statement::If {
condition,
accept,
reject,
}
}
ast::StatementKind::Switch {
selector,
ref cases,
} => {
let mut emitter = Emitter::default();
emitter.start(&ctx.function.expressions);
let mut ectx = ctx.as_expression(block, &mut emitter);
let selector = self.expression(selector, &mut ectx)?;
let uint =
resolve_inner!(ectx, selector).scalar_kind() == Some(crate::ScalarKind::Uint);
block.extend(emitter.finish(&ctx.function.expressions));
let cases = cases
.iter()
.map(|case| {
Ok(crate::SwitchCase {
value: match case.value {
ast::SwitchValue::Expr(expr) => {
let span = ctx.ast_expressions.get_span(expr);
let expr =
self.expression(expr, &mut ctx.as_global().as_const())?;
match ctx.module.to_ctx().eval_expr_to_literal(expr) {
Some(crate::Literal::I32(value)) if !uint => {
crate::SwitchValue::I32(value)
}
Some(crate::Literal::U32(value)) if uint => {
crate::SwitchValue::U32(value)
}
_ => {
return Err(Error::InvalidSwitchValue { uint, span });
}
}
}
ast::SwitchValue::Default => crate::SwitchValue::Default,
},
body: self.block(&case.body, is_inside_loop, ctx)?,
fall_through: case.fall_through,
})
})
.collect::<Result<_, _>>()?;
crate::Statement::Switch { selector, cases }
}
ast::StatementKind::Loop {
ref body,
ref continuing,
break_if,
} => {
let body = self.block(body, true, ctx)?;
let mut continuing = self.block(continuing, true, ctx)?;
let mut emitter = Emitter::default();
emitter.start(&ctx.function.expressions);
let break_if = break_if
.map(|expr| {
self.expression(expr, &mut ctx.as_expression(&mut continuing, &mut emitter))
})
.transpose()?;
--> --------------------
--> maximum size reached
--> --------------------
[ Konzepte0.52Was zu einem Entwurf gehört
Wie die Entwicklung von Software durchgeführt wird
]
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2026-04-04
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