Rollup merge of #84404 - tmiasko:intrinsics-in-coercion-lub, r=Mark-Simulacrum

Check for intrinsics before coercing to a function pointer

Return an error if coercing function items / non-capturing closures
to a common function pointer type would require reifying an intrinsic.

Turns ICE reported in #84297 into a proper error.

1 files changed, 8 insertions, 0 deletions

diff --git a/compiler/rustc_typeck/src/check/coercion.rs b/compiler/rustc_typeck/src/check/coercion.rs
index fd7c50e9788..427f967a9b6 100644
--- a/compiler/rustc_typeck/src/check/coercion.rs
+++ b/compiler/rustc_typeck/src/check/coercion.rs
@@ -973,6 +973,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         };
         if let (Some(a_sig), Some(b_sig)) = (a_sig, b_sig) {
+            // Intrinsics are not coercible to function pointers.
+            if a_sig.abi() == Abi::RustIntrinsic
+                || a_sig.abi() == Abi::PlatformIntrinsic
+                || b_sig.abi() == Abi::RustIntrinsic
+                || b_sig.abi() == Abi::PlatformIntrinsic
+            {
+                return Err(TypeError::IntrinsicCast);
+            }
             // The signature must match.
             let a_sig = self.normalize_associated_types_in(new.span, a_sig);
             let b_sig = self.normalize_associated_types_in(new.span, b_sig);