3 () => ( $crate::bug!("impossible case reached") );
4 ($msg:expr) => ({ $crate::util::bug::bug_fmt(::std::format_args!($msg)) });
5 ($msg:expr,) => ({ $crate::bug!($msg) });
6 ($fmt:expr, $($arg:tt)+) => ({
7 $crate::util::bug::bug_fmt(::std::format_args!($fmt, $($arg)+))
12 macro_rules! span_bug {
13 ($span:expr, $msg:expr) => ({ $crate::util::bug::span_bug_fmt($span, ::std::format_args!($msg)) });
14 ($span:expr, $msg:expr,) => ({ $crate::span_bug!($span, $msg) });
15 ($span:expr, $fmt:expr, $($arg:tt)+) => ({
16 $crate::util::bug::span_bug_fmt($span, ::std::format_args!($fmt, $($arg)+))
20 ///////////////////////////////////////////////////////////////////////////
21 // Lift and TypeFoldable/TypeVisitable macros
23 // When possible, use one of these (relatively) convenient macros to write
27 macro_rules! CloneLiftImpls {
28 (for <$tcx:lifetime> { $($ty:ty,)+ }) => {
30 impl<$tcx> $crate::ty::Lift<$tcx> for $ty {
32 fn lift_to_tcx(self, _: $crate::ty::TyCtxt<$tcx>) -> Option<Self> {
48 /// Used for types that are `Copy` and which **do not care arena
49 /// allocated data** (i.e., don't need to be folded).
51 macro_rules! TrivialTypeTraversalImpls {
52 (for <$tcx:lifetime> { $($ty:ty,)+ }) => {
54 impl<$tcx> $crate::ty::fold::TypeFoldable<$tcx> for $ty {
55 fn try_fold_with<F: $crate::ty::fold::FallibleTypeFolder<$tcx>>(
58 ) -> ::std::result::Result<Self, F::Error> {
63 fn fold_with<F: $crate::ty::fold::TypeFolder<$tcx>>(
71 impl<$tcx> $crate::ty::visit::TypeVisitable<$tcx> for $ty {
73 fn visit_with<F: $crate::ty::visit::TypeVisitor<$tcx>>(
76 -> ::std::ops::ControlFlow<F::BreakTy>
78 ::std::ops::ControlFlow::CONTINUE
85 TrivialTypeTraversalImpls! {
94 macro_rules! TrivialTypeTraversalAndLiftImpls {
96 TrivialTypeTraversalImpls! { $($t)* }
97 CloneLiftImpls! { $($t)* }
102 macro_rules! EnumTypeTraversalImpl {
103 (impl<$($p:tt),*> TypeFoldable<$tcx:tt> for $s:path {
105 } $(where $($wc:tt)*)*) => {
106 impl<$($p),*> $crate::ty::fold::TypeFoldable<$tcx> for $s
109 fn try_fold_with<V: $crate::ty::fold::FallibleTypeFolder<$tcx>>(
112 ) -> ::std::result::Result<Self, V::Error> {
113 EnumTypeTraversalImpl!(@FoldVariants(self, folder) input($($variants)*) output())
118 (impl<$($p:tt),*> TypeVisitable<$tcx:tt> for $s:path {
120 } $(where $($wc:tt)*)*) => {
121 impl<$($p),*> $crate::ty::visit::TypeVisitable<$tcx> for $s
124 fn visit_with<V: $crate::ty::visit::TypeVisitor<$tcx>>(
127 ) -> ::std::ops::ControlFlow<V::BreakTy> {
128 EnumTypeTraversalImpl!(@VisitVariants(self, visitor) input($($variants)*) output())
133 (@FoldVariants($this:expr, $folder:expr) input() output($($output:tt)*)) => {
139 (@FoldVariants($this:expr, $folder:expr)
140 input( ($variant:path) ( $($variant_arg:ident),* ) , $($input:tt)*)
141 output( $($output:tt)*) ) => {
142 EnumTypeTraversalImpl!(
143 @FoldVariants($this, $folder)
146 $variant ( $($variant_arg),* ) => {
148 $($crate::ty::fold::TypeFoldable::try_fold_with($variant_arg, $folder)?),*
156 (@FoldVariants($this:expr, $folder:expr)
157 input( ($variant:path) { $($variant_arg:ident),* $(,)? } , $($input:tt)*)
158 output( $($output:tt)*) ) => {
159 EnumTypeTraversalImpl!(
160 @FoldVariants($this, $folder)
163 $variant { $($variant_arg),* } => {
165 $($variant_arg: $crate::ty::fold::TypeFoldable::fold_with(
166 $variant_arg, $folder
174 (@FoldVariants($this:expr, $folder:expr)
175 input( ($variant:path), $($input:tt)*)
176 output( $($output:tt)*) ) => {
177 EnumTypeTraversalImpl!(
178 @FoldVariants($this, $folder)
181 $variant => { $variant }
187 (@VisitVariants($this:expr, $visitor:expr) input() output($($output:tt)*)) => {
193 (@VisitVariants($this:expr, $visitor:expr)
194 input( ($variant:path) ( $($variant_arg:ident),* ) , $($input:tt)*)
195 output( $($output:tt)*) ) => {
196 EnumTypeTraversalImpl!(
197 @VisitVariants($this, $visitor)
200 $variant ( $($variant_arg),* ) => {
201 $($crate::ty::visit::TypeVisitable::visit_with(
202 $variant_arg, $visitor
204 ::std::ops::ControlFlow::CONTINUE
211 (@VisitVariants($this:expr, $visitor:expr)
212 input( ($variant:path) { $($variant_arg:ident),* $(,)? } , $($input:tt)*)
213 output( $($output:tt)*) ) => {
214 EnumTypeTraversalImpl!(
215 @VisitVariants($this, $visitor)
218 $variant { $($variant_arg),* } => {
219 $($crate::ty::visit::TypeVisitable::visit_with(
220 $variant_arg, $visitor
222 ::std::ops::ControlFlow::CONTINUE
229 (@VisitVariants($this:expr, $visitor:expr)
230 input( ($variant:path), $($input:tt)*)
231 output( $($output:tt)*) ) => {
232 EnumTypeTraversalImpl!(
233 @VisitVariants($this, $visitor)
236 $variant => { ::std::ops::ControlFlow::CONTINUE }