pub(super) fn lower_expr_mut(&mut self, e: &Expr) -> hir::Expr<'hir> {
ensure_sufficient_stack(|| {
+ match &e.kind {
+ // Paranthesis expression does not have a HirId and is handled specially.
+ ExprKind::Paren(ex) => {
+ let mut ex = self.lower_expr_mut(ex);
+ // Include parens in span, but only if it is a super-span.
+ if e.span.contains(ex.span) {
+ ex.span = self.lower_span(e.span);
+ }
+ // Merge attributes into the inner expression.
+ if !e.attrs.is_empty() {
+ let old_attrs =
+ self.attrs.get(&ex.hir_id.local_id).map(|la| *la).unwrap_or(&[]);
+ self.attrs.insert(
+ ex.hir_id.local_id,
+ &*self.arena.alloc_from_iter(
+ e.attrs
+ .iter()
+ .map(|a| self.lower_attr(a))
+ .chain(old_attrs.iter().cloned()),
+ ),
+ );
+ }
+ return ex;
+ }
+ // Desugar `ExprForLoop`
+ // from: `[opt_ident]: for <pat> in <head> <body>`
+ //
+ // This also needs special handling because the HirId of the returned `hir::Expr` will not
+ // correspond to the `e.id`, so `lower_expr_for` handles attribute lowering itself.
+ ExprKind::ForLoop(pat, head, body, opt_label) => {
+ return self.lower_expr_for(e, pat, head, body, *opt_label);
+ }
+ _ => (),
+ }
+
let hir_id = self.lower_node_id(e.id);
self.lower_attrs(hir_id, &e.attrs);
if e.attrs.get(0).map_or(false, |a| a.has_name(sym::rustc_box)) {
if let [inner] = &args[..] && e.attrs.len() == 1 {
let kind = hir::ExprKind::Box(self.lower_expr(&inner));
- let hir_id = self.lower_node_id(e.id);
return hir::Expr { hir_id, kind, span: self.lower_span(e.span) };
} else {
self.tcx.sess.emit_err(RustcBoxAttributeError { span: e.span });
ExprKind::Yield(opt_expr) => self.lower_expr_yield(e.span, opt_expr.as_deref()),
ExprKind::Err => hir::ExprKind::Err,
ExprKind::Try(sub_expr) => self.lower_expr_try(e.span, sub_expr),
- ExprKind::Paren(ex) => {
- let mut ex = self.lower_expr_mut(ex);
- // Include parens in span, but only if it is a super-span.
- if e.span.contains(ex.span) {
- ex.span = self.lower_span(e.span);
- }
- // Merge attributes into the inner expression.
- if !e.attrs.is_empty() {
- let old_attrs =
- self.attrs.get(&ex.hir_id.local_id).map(|la| *la).unwrap_or(&[]);
- self.attrs.insert(
- ex.hir_id.local_id,
- &*self.arena.alloc_from_iter(
- e.attrs
- .iter()
- .map(|a| self.lower_attr(a))
- .chain(old_attrs.iter().cloned()),
- ),
- );
- }
- return ex;
- }
- // Desugar `ExprForLoop`
- // from: `[opt_ident]: for <pat> in <head> <body>`
- ExprKind::ForLoop(pat, head, body, opt_label) => {
- return self.lower_expr_for(e, pat, head, body, *opt_label);
- }
+ ExprKind::Paren(_) | ExprKind::ForLoop(..) => unreachable!("already handled"),
+
ExprKind::MacCall(_) => panic!("{:?} shouldn't exist here", e.span),
};
projects / rust.git / commitdiff