Rollup merge of #145323 - scrabsha:push-pqwvmznzzmpr, r=jdonszelmann

Port the `#[linkage]` attribute to the new attribute system

r? `@jdonszelmann`

5 files changed, 30 insertions, 60 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 0494666bda9..77096822fdc 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -306,7 +306,8 @@ fn exported_generic_symbols_provider_local<'tcx>(
     let mut symbols: Vec<_> = vec![];
 
     if tcx.local_crate_exports_generics() {
-        use rustc_middle::mir::mono::{Linkage, MonoItem, Visibility};
+        use rustc_hir::attrs::Linkage;
+        use rustc_middle::mir::mono::{MonoItem, Visibility};
         use rustc_middle::ty::InstanceKind;
 
         // Normally, we require that shared monomorphizations are not hidden,
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index 287787eb3d1..a36a772bc97 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -11,7 +11,6 @@ use rustc_hir::{self as hir, Attribute, LangItem, find_attr, lang_items};
 use rustc_middle::middle::codegen_fn_attrs::{
     CodegenFnAttrFlags, CodegenFnAttrs, PatchableFunctionEntry,
 };
-use rustc_middle::mir::mono::Linkage;
 use rustc_middle::query::Providers;
 use rustc_middle::span_bug;
 use rustc_middle::ty::{self as ty, TyCtxt};
@@ -26,31 +25,6 @@ use crate::target_features::{
     check_target_feature_trait_unsafe, check_tied_features, from_target_feature_attr,
 };
 
-fn linkage_by_name(tcx: TyCtxt<'_>, def_id: LocalDefId, name: &str) -> Linkage {
-    use rustc_middle::mir::mono::Linkage::*;
-
-    // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
-    // applicable to variable declarations and may not really make sense for
-    // Rust code in the first place but allow them anyway and trust that the
-    // user knows what they're doing. Who knows, unanticipated use cases may pop
-    // up in the future.
-    //
-    // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
-    // and don't have to be, LLVM treats them as no-ops.
-    match name {
-        "available_externally" => AvailableExternally,
-        "common" => Common,
-        "extern_weak" => ExternalWeak,
-        "external" => External,
-        "internal" => Internal,
-        "linkonce" => LinkOnceAny,
-        "linkonce_odr" => LinkOnceODR,
-        "weak" => WeakAny,
-        "weak_odr" => WeakODR,
-        _ => tcx.dcx().span_fatal(tcx.def_span(def_id), "invalid linkage specified"),
-    }
-}
-
 /// In some cases, attributes are only valid on functions, but it's the `check_attr`
 /// pass that checks that they aren't used anywhere else, rather than this module.
 /// In these cases, we bail from performing further checks that are only meaningful for
@@ -103,13 +77,6 @@ fn parse_instruction_set_attr(tcx: TyCtxt<'_>, attr: &Attribute) -> Option<Instr
     }
 }
 
-// FIXME(jdonszelmann): remove when linkage becomes a parsed attr
-fn parse_linkage_attr(tcx: TyCtxt<'_>, did: LocalDefId, attr: &Attribute) -> Option<Linkage> {
-    let val = attr.value_str()?;
-    let linkage = linkage_by_name(tcx, did, val.as_str());
-    Some(linkage)
-}
-
 // FIXME(jdonszelmann): remove when no_sanitize becomes a parsed attr
 fn parse_no_sanitize_attr(tcx: TyCtxt<'_>, attr: &Attribute) -> Option<SanitizerSet> {
     let list = attr.meta_item_list()?;
@@ -332,6 +299,28 @@ fn process_builtin_attrs(
                 AttributeKind::StdInternalSymbol(_) => {
                     codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL
                 }
+                AttributeKind::Linkage(linkage, _) => {
+                    let linkage = Some(*linkage);
+
+                    if tcx.is_foreign_item(did) {
+                        codegen_fn_attrs.import_linkage = linkage;
+
+                        if tcx.is_mutable_static(did.into()) {
+                            let mut diag = tcx.dcx().struct_span_err(
+                                attr.span(),
+                                "extern mutable statics are not allowed with `#[linkage]`",
+                            );
+                            diag.note(
+                                "marking the extern static mutable would allow changing which \
+                                symbol the static references rather than make the target of the \
+                                symbol mutable",
+                            );
+                            diag.emit();
+                        }
+                    } else {
+                        codegen_fn_attrs.linkage = linkage;
+                    }
+                }
                 _ => {}
             }
         }
@@ -349,28 +338,6 @@ fn process_builtin_attrs(
                 codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED
             }
             sym::thread_local => codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL,
-            sym::linkage => {
-                let linkage = parse_linkage_attr(tcx, did, attr);
-
-                if tcx.is_foreign_item(did) {
-                    codegen_fn_attrs.import_linkage = linkage;
-
-                    if tcx.is_mutable_static(did.into()) {
-                        let mut diag = tcx.dcx().struct_span_err(
-                            attr.span(),
-                            "extern mutable statics are not allowed with `#[linkage]`",
-                        );
-                        diag.note(
-                            "marking the extern static mutable would allow changing which \
-                            symbol the static references rather than make the target of the \
-                            symbol mutable",
-                        );
-                        diag.emit();
-                    }
-                } else {
-                    codegen_fn_attrs.linkage = linkage;
-                }
-            }
             sym::no_sanitize => {
                 interesting_spans.no_sanitize = Some(attr.span());
                 codegen_fn_attrs.no_sanitize |=
diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
index 2a9b5c9019b..31784cabf4a 100644
--- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
@@ -1,6 +1,6 @@
 use rustc_abi::{BackendRepr, Float, Integer, Primitive, RegKind};
-use rustc_hir::attrs::InstructionSetAttr;
-use rustc_middle::mir::mono::{Linkage, MonoItemData, Visibility};
+use rustc_hir::attrs::{InstructionSetAttr, Linkage};
+use rustc_middle::mir::mono::{MonoItemData, Visibility};
 use rustc_middle::mir::{InlineAsmOperand, START_BLOCK};
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{Instance, Ty, TyCtxt, TypeVisitableExt};
diff --git a/compiler/rustc_codegen_ssa/src/mono_item.rs b/compiler/rustc_codegen_ssa/src/mono_item.rs
index b9040c330fb..8f03dc1e6b5 100644
--- a/compiler/rustc_codegen_ssa/src/mono_item.rs
+++ b/compiler/rustc_codegen_ssa/src/mono_item.rs
@@ -1,5 +1,6 @@
+use rustc_hir::attrs::Linkage;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
-use rustc_middle::mir::mono::{Linkage, MonoItem, MonoItemData, Visibility};
+use rustc_middle::mir::mono::{MonoItem, MonoItemData, Visibility};
 use rustc_middle::ty::layout::HasTyCtxt;
 use tracing::debug;
 
diff --git a/compiler/rustc_codegen_ssa/src/traits/declare.rs b/compiler/rustc_codegen_ssa/src/traits/declare.rs
index 9f735546558..8d5f0a5b939 100644
--- a/compiler/rustc_codegen_ssa/src/traits/declare.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/declare.rs
@@ -1,5 +1,6 @@
+use rustc_hir::attrs::Linkage;
 use rustc_hir::def_id::DefId;
-use rustc_middle::mir::mono::{Linkage, Visibility};
+use rustc_middle::mir::mono::Visibility;
 use rustc_middle::ty::Instance;
 
 pub trait PreDefineCodegenMethods<'tcx> {