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authorSamuel Tardieu <sam@rfc1149.net>2025-08-02 11:24:26 +0200
committerGitHub <noreply@github.com>2025-08-02 11:24:26 +0200
commit179b4b6691bb3a8201cf08fa9d68ca613e9173c3 (patch)
tree84fcaf5f6ea5ecb996937df066671c14836b7d5b
parent7e8ef3a818df467df052d1b06faab79045afd3ee (diff)
parent5aec4379e304ef280ee9a470e7ab121e4a81fd17 (diff)
downloadrust-179b4b6691bb3a8201cf08fa9d68ca613e9173c3.tar.gz
rust-179b4b6691bb3a8201cf08fa9d68ca613e9173c3.zip
Rollup merge of #144756 - WaffleLapkin:inf-rec-etc-ctfe, r=lqd
detect infinite recursion with tail calls in ctfe

fixes rust-lang/rust#144753
-rw-r--r--compiler/rustc_mir_transform/src/ctfe_limit.rs2
-rw-r--r--tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs10
-rw-r--r--tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr17
3 files changed, 28 insertions, 1 deletions
diff --git a/compiler/rustc_mir_transform/src/ctfe_limit.rs b/compiler/rustc_mir_transform/src/ctfe_limit.rs
index fb17cca30f4..ac46336b834 100644
--- a/compiler/rustc_mir_transform/src/ctfe_limit.rs
+++ b/compiler/rustc_mir_transform/src/ctfe_limit.rs
@@ -18,7 +18,7 @@ impl<'tcx> crate::MirPass<'tcx> for CtfeLimit {
             .basic_blocks
             .iter_enumerated()
             .filter_map(|(node, node_data)| {
-                if matches!(node_data.terminator().kind, TerminatorKind::Call { .. })
+                if matches!(node_data.terminator().kind, TerminatorKind::Call { .. } | TerminatorKind::TailCall { .. })
                     // Back edges in a CFG indicate loops
                     || has_back_edge(doms, node, node_data)
                 {
diff --git a/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs
new file mode 100644
index 00000000000..0c55f13c16c
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.rs
@@ -0,0 +1,10 @@
+#![feature(explicit_tail_calls)]
+#![expect(incomplete_features)]
+
+const _: () = f();
+
+const fn f() {
+    become f(); //~ error: constant evaluation is taking a long time
+}
+
+fn main() {}
diff --git a/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr
new file mode 100644
index 00000000000..b5a96114a58
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/infinite-recursion-in-ctfe.stderr
@@ -0,0 +1,17 @@
+error: constant evaluation is taking a long time
+  --> $DIR/infinite-recursion-in-ctfe.rs:7:5
+   |
+LL |     become f();
+   |     ^^^^^^^^^^
+   |
+   = note: this lint makes sure the compiler doesn't get stuck due to infinite loops in const eval.
+           If your compilation actually takes a long time, you can safely allow the lint.
+help: the constant being evaluated
+  --> $DIR/infinite-recursion-in-ctfe.rs:4:1
+   |
+LL | const _: () = f();
+   | ^^^^^^^^^^^
+   = note: `#[deny(long_running_const_eval)]` on by default
+
+error: aborting due to 1 previous error
+