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 rust-lang/rust#74708,
which was also an `ensure_sufficient_stack` in this area of code at the
time. However, the refactor in rust-lang/rust#92573 basically left that
to the general `MutVisitor`, and then rust-lang/rust#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.
This commit is contained in:
Josh Stone
2025-08-14 16:02:31 -07:00
parent be00ea1968
commit f68bcb376d

View File

@@ -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_parse::parser::{
@@ -2437,7 +2438,7 @@ 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) {