Auto merge of #123052 - maurer:addr-taken, r=compiler-errors

CFI: Support function pointers for trait methods

Adds support for both CFI and KCFI for function pointers to trait methods by attaching both concrete and abstract types to functions.

KCFI does this through generation of a `ReifyShim` on any function pointer for a method that could go into a vtable, and keeping this separate from `ReifyShim`s that are *intended* for vtable us by setting a `ReifyReason` on them.

CFI does this by setting both the concrete and abstract type on every instance.

This should land after #123024 or a similar PR, as it diverges the implementation of CFI vs KCFI.

r? `@compiler-errors`

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/rustc_codegen_llvm/src/declare.rs b/compiler/rustc_codegen_llvm/src/declare.rs
index 3ef8538ced3..f58dd4066ad 100644
--- a/compiler/rustc_codegen_llvm/src/declare.rs
+++ b/compiler/rustc_codegen_llvm/src/declare.rs
@@ -147,7 +147,7 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
                 for options in [
                     TypeIdOptions::GENERALIZE_POINTERS,
                     TypeIdOptions::NORMALIZE_INTEGERS,
-                    TypeIdOptions::NO_SELF_TYPE_ERASURE,
+                    TypeIdOptions::ERASE_SELF_TYPE,
                 ]
                 .into_iter()
                 .powerset()
@@ -173,7 +173,9 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
 
         if self.tcx.sess.is_sanitizer_kcfi_enabled() {
             // LLVM KCFI does not support multiple !kcfi_type attachments
-            let mut options = TypeIdOptions::empty();
+            // Default to erasing the self type. If we need the concrete type, there will be a
+            // hint in the instance.
+            let mut options = TypeIdOptions::ERASE_SELF_TYPE;
             if self.tcx.sess.is_sanitizer_cfi_generalize_pointers_enabled() {
                 options.insert(TypeIdOptions::GENERALIZE_POINTERS);
             }