Auto merge of #145410 - cuviper:expand-stack, r=lqd

rustc_expand: ensure stack in `InvocationCollector::visit_expr`

In Fedora, when we built rustc with PGO on ppc64le, we started failing
the test `issue-74564-if-expr-stack-overflow.rs`. This could also be
reproduced on other arches by setting a smaller `RUST_MIN_STACK`, so
it's probably just unlucky that ppc64le PGO created a large stack frame
somewhere in this recursion path. Adding an `ensure_sufficient_stack`
solves the stack overflow.

Historically, that test and its fix were added in #74708,
which was also an `ensure_sufficient_stack` in this area of code at the
time. However, the refactor in #92573 basically left that
to the general `MutVisitor`, and then #142240 removed even
that ensure call. It may be luck that our tier-1 tested targets did not
regress the original issue across those refactors.

Author: bors

compiler/rustc_expand/src/expand.rs

@@ -14,6 +14,7 @@ use rustc_ast::{
 use rustc_ast_pretty::pprust;
 use rustc_attr_parsing::{EvalConfigResult, ShouldEmit};
 use rustc_data_structures::flat_map_in_place::FlatMapInPlace;
+use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::PResult;
 use rustc_feature::Features;
 use rustc_hir::def::MacroKinds;
@@ -2469,7 +2470,7 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
         if let Some(attr) = node.attrs.first() {
             self.cfg().maybe_emit_expr_attr_err(attr);
         }
-        self.visit_node(node)
+        ensure_sufficient_stack(|| self.visit_node(node))
     }
 
     fn visit_method_receiver_expr(&mut self, node: &mut ast::Expr) {