Rollup merge of #143293 - folkertdev:naked-function-kcfi, r=compiler-errors

fix `-Zsanitizer=kcfi` on `#[naked]` functions

fixes https://github.com/rust-lang/rust/issues/143266

With `-Zsanitizer=kcfi`, indirect calls happen via generated intermediate shim that forwards the call. The generated shim preserves the attributes of the original, including `#[unsafe(naked)]`. The shim is not a naked function though, and violates its invariants (like having a body that consists of a single `naked_asm!` call).

My fix here is to match on the `InstanceKind`, and only use `codegen_naked_asm` when the instance is not a `ReifyShim`. That does beg the question whether there are other `InstanceKind`s that could come up. As far as I can tell the answer is no: calling via `dyn` seems to work find, and `#[track_caller]` is disallowed in combination with `#[naked]`.

r? codegen
````@rustbot```` label +A-naked
cc ````@maurer```` ````@rcvalle````

1 files changed, 9 insertions, 0 deletions

diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 935cc889574..3c1be069c9e 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1505,6 +1505,15 @@ rustc_queries! {
         separate_provide_extern
     }
 
+    /// Returns the `CodegenFnAttrs` for the item at `def_id`.
+    ///
+    /// If possible, use `tcx.codegen_instance_attrs` instead. That function takes the
+    /// instance kind into account.
+    ///
+    /// For example, the `#[naked]` attribute should be applied for `InstanceKind::Item`,
+    /// but should not be applied if the instance kind is `InstanceKind::ReifyShim`.
+    /// Using this query would include the attribute regardless of the actual instance
+    /// kind at the call site.
     query codegen_fn_attrs(def_id: DefId) -> &'tcx CodegenFnAttrs {
         desc { |tcx| "computing codegen attributes of `{}`", tcx.def_path_str(def_id) }
         arena_cache