CFI: Fix (3) of core and std have explict CFI violations

Fixes (3) of rust-lang#115199 by transforming function items, closures, and Fn
trait objects into function pointers.

compiler/rustc_middle/src/ty/sty.rs

@@ -1831,6 +1831,11 @@ impl<'tcx> Ty<'tcx> {
         self.0.0.flags
     }
 
+    #[inline]
+    pub fn is_tuple(self) -> bool {
+        matches!(self.kind(), Tuple(..))
+    }
+
     #[inline]
     pub fn is_unit(self) -> bool {
         match self.kind() {
@@ -2207,6 +2212,11 @@ impl<'tcx> Ty<'tcx> {
         matches!(self.kind(), FnDef(..) | FnPtr(_))
     }
 
+    #[inline]
+    pub fn is_fn_def(self) -> bool {
+        matches!(self.kind(), FnDef(..))
+    }
+
     #[inline]
     pub fn is_fn_ptr(self) -> bool {
         matches!(self.kind(), FnPtr(_))

compiler/rustc_symbol_mangling/src/lib.rs

@@ -91,6 +91,8 @@
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
 #![allow(internal_features)]
+#![feature(iter_order_by)]
+#![feature(let_chains)]
 
 #[macro_use]
 extern crate rustc_middle;

compiler/rustc_symbol_mangling/src/typeid.rs

@@ -4,7 +4,7 @@
 /// For more information about LLVM CFI and cross-language LLVM CFI support for the Rust compiler,
 /// see design document in the tracking issue #89653.
 use bitflags::bitflags;
-use rustc_middle::ty::{Instance, Ty, TyCtxt};
+use rustc_middle::ty::{Instance, List, Ty, TyCtxt};
 use rustc_target::abi::call::FnAbi;
 use std::hash::Hasher;
 use twox_hash::XxHash64;
@@ -27,7 +27,11 @@ pub fn typeid_for_fnabi<'tcx>(
     fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
     options: TypeIdOptions,
 ) -> String {
-    typeid_itanium_cxx_abi::typeid_for_fnabi(tcx, fn_abi, options)
+    typeid_itanium_cxx_abi::typeid_for_fnabi(
+        tcx,
+        &typeid_itanium_cxx_abi::transform_fnabi(tcx, &fn_abi, options, None),
+        options,
+    )
 }
 
 /// Returns a type metadata identifier for the specified Instance.
@@ -36,7 +40,16 @@ pub fn typeid_for_instance<'tcx>(
     instance: &Instance<'tcx>,
     options: TypeIdOptions,
 ) -> String {
-    typeid_itanium_cxx_abi::typeid_for_instance(tcx, instance, options)
+    let fn_abi = tcx
+        .fn_abi_of_instance(tcx.param_env(instance.def_id()).and((*instance, List::empty())))
+        .unwrap_or_else(|instance| {
+            bug!("typeid_for_instance: couldn't get fn_abi of instance {:?}", instance)
+        });
+    typeid_itanium_cxx_abi::typeid_for_fnabi(
+        tcx,
+        &typeid_itanium_cxx_abi::transform_fnabi(tcx, &fn_abi, options, Some(instance)),
+        options,
+    )
 }
 
 /// Returns a KCFI type metadata identifier for the specified FnAbi.
@@ -48,7 +61,14 @@ pub fn kcfi_typeid_for_fnabi<'tcx>(
     // A KCFI type metadata identifier is a 32-bit constant produced by taking the lower half of the
     // xxHash64 of the type metadata identifier. (See llvm/llvm-project@cff5bef.)
     let mut hash: XxHash64 = Default::default();
-    hash.write(typeid_itanium_cxx_abi::typeid_for_fnabi(tcx, fn_abi, options).as_bytes());
+    hash.write(
+        typeid_itanium_cxx_abi::typeid_for_fnabi(
+            tcx,
+            &typeid_itanium_cxx_abi::transform_fnabi(tcx, &fn_abi, options, None),
+            options,
+        )
+        .as_bytes(),
+    );
     hash.finish() as u32
 }
 
@@ -58,9 +78,21 @@ pub fn kcfi_typeid_for_instance<'tcx>(
     instance: &Instance<'tcx>,
     options: TypeIdOptions,
 ) -> u32 {
+    let fn_abi = tcx
+        .fn_abi_of_instance(tcx.param_env(instance.def_id()).and((*instance, List::empty())))
+        .unwrap_or_else(|instance| {
+            bug!("typeid_for_instance: couldn't get fn_abi of instance {:?}", instance)
+        });
     // A KCFI type metadata identifier is a 32-bit constant produced by taking the lower half of the
     // xxHash64 of the type metadata identifier. (See llvm/llvm-project@cff5bef.)
     let mut hash: XxHash64 = Default::default();
-    hash.write(typeid_itanium_cxx_abi::typeid_for_instance(tcx, instance, options).as_bytes());
+    hash.write(
+        typeid_itanium_cxx_abi::typeid_for_fnabi(
+            tcx,
+            &typeid_itanium_cxx_abi::transform_fnabi(tcx, &fn_abi, options, Some(instance)),
+            options,
+        )
+        .as_bytes(),
+    );
     hash.finish() as u32
 }