make naked functions always have external linkage *in LLVM*. If we do it earlier, then some other logic causes invalid visibility for the item (exporting when it shouldn't).

Author: folkertdev

compiler/rustc_codegen_llvm/src/mono_item.rs

@@ -2,7 +2,6 @@ use rustc_codegen_ssa::traits::*;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::bug;
-use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir::mono::{Linkage, Visibility};
 use rustc_middle::ty::layout::{FnAbiOf, HasTypingEnv, LayoutOf};
 use rustc_middle::ty::{self, Instance, TypeVisitableExt};
@@ -60,14 +59,7 @@ impl<'tcx> PreDefineCodegenMethods<'tcx> for CodegenCx<'_, 'tcx> {
         let fn_abi = self.fn_abi_of_instance(instance, ty::List::empty());
         let lldecl = self.declare_fn(symbol_name, fn_abi, Some(instance));
         let attrs = self.tcx.codegen_fn_attrs(instance.def_id());
-        let llvm_linkage =
-            if attrs.flags.contains(CodegenFnAttrFlags::NAKED) && linkage == Linkage::Internal {
-                // this is effectively an extern fn, and must have external linkage
-                llvm::Linkage::ExternalLinkage
-            } else {
-                base::linkage_to_llvm(linkage)
-            };
-        llvm::set_linkage(lldecl, llvm_linkage);
+        llvm::set_linkage(lldecl, base::linkage_to_llvm(linkage));
         base::set_link_section(lldecl, attrs);
         if (linkage == Linkage::LinkOnceODR || linkage == Linkage::WeakODR)
             && self.tcx.sess.target.supports_comdat()

tests/ui/asm/naked-functions.rs

@@ -186,7 +186,7 @@ pub unsafe extern "C" fn invalid_asm_syntax(a: u32) -> u32 {
 // this previously ICE'd, see https://github.com/rust-lang/rust/issues/124375
 #[naked]
 pub unsafe extern "C" fn naked_with_args_and_return(a: isize, b: isize) -> isize {
-    asm!("lea rax, [rdi + rsi]", "ret", options(noreturn));
+    naked_asm!("lea rax, [rdi + rsi]", "ret");
 }
 
 #[cfg(target_arch = "x86_64")]