Add a convenience function for testing whether a static is #[thread_local]

Author: oli-obk

src/librustc_codegen_llvm/consts.rs

@@ -212,6 +212,7 @@ impl CodegenCx<'ll, 'tcx> {
         let g = if let Some(def_id) = def_id.as_local() {
             let id = self.tcx.hir().as_local_hir_id(def_id);
             let llty = self.layout_of(ty).llvm_type(self);
+            // FIXME: refactor this to work without accessing the HIR
             let (g, attrs) = match self.tcx.hir().get(id) {
                 Node::Item(&hir::Item { attrs, span, kind: hir::ItemKind::Static(..), .. }) => {
                     let sym_str = sym.as_str();

src/librustc_middle/ty/util.rs

@@ -1,6 +1,7 @@
 //! Miscellaneous type-system utilities that are too small to deserve their own modules.
 
 use crate::ich::NodeIdHashingMode;
+use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use crate::mir::interpret::{sign_extend, truncate};
 use crate::ty::layout::IntegerExt;
 use crate::ty::query::TyCtxtAt;
@@ -528,6 +529,11 @@ impl<'tcx> TyCtxt<'tcx> {
         self.static_mutability(def_id).is_some()
     }
 
+    /// Returns `true` if this is a `static` item with the `#[thread_local]` attribute.
+    pub fn is_thread_local_static(&self, def_id: DefId) -> bool {
+        self.codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::THREAD_LOCAL)
+    }
+
     /// Returns `true` if the node pointed to by `def_id` is a mutable `static` item.
     pub fn is_mutable_static(&self, def_id: DefId) -> bool {
         self.static_mutability(def_id) == Some(hir::Mutability::Mut)

src/librustc_mir/transform/check_consts/validation.rs

@@ -8,7 +8,6 @@ use rustc_middle::mir::visit::{MutatingUseContext, NonMutatingUseContext, PlaceC
 use rustc_middle::mir::*;
 use rustc_middle::ty::cast::CastTy;
 use rustc_middle::ty::{self, Instance, InstanceDef, TyCtxt};
-use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt;
 use rustc_trait_selection::traits::{self, TraitEngine};
@@ -224,7 +223,7 @@ impl Validator<'mir, 'tcx> {
 
         // Ensure that the end result is `Sync` in a non-thread local `static`.
         let should_check_for_sync =
-            const_kind == Some(ConstKind::Static) && !tcx.has_attr(def_id, sym::thread_local);
+            const_kind == Some(ConstKind::Static) && !tcx.is_thread_local_static(def_id);
 
         if should_check_for_sync {
             let hir_id = tcx.hir().as_local_hir_id(def_id.expect_local());
@@ -267,8 +266,7 @@ impl Validator<'mir, 'tcx> {
     }
 
     fn check_static(&mut self, def_id: DefId, span: Span) {
-        let is_thread_local = self.tcx.has_attr(def_id, sym::thread_local);
-        if is_thread_local {
+        if self.tcx.is_thread_local_static(def_id) {
             self.check_op_spanned(ops::ThreadLocalAccess, span)
         } else {
             self.check_op_spanned(ops::StaticAccess, span)

src/librustc_mir/transform/promote_consts.rs

@@ -522,7 +522,7 @@ impl<'tcx> Validator<'_, 'tcx> {
                         return Err(Unpromotable);
                     }
 
-                    let is_thread_local = self.tcx.has_attr(def_id, sym::thread_local);
+                    let is_thread_local = self.tcx.is_thread_local_static(def_id);
                     if is_thread_local {
                         return Err(Unpromotable);
                     }

src/librustc_mir_build/build/expr/as_temp.rs

@@ -3,10 +3,9 @@
 use crate::build::scope::DropKind;
 use crate::build::{BlockAnd, BlockAndExtension, Builder};
 use crate::hair::*;
+use rustc_hir as hir;
 use rustc_middle::middle::region;
 use rustc_middle::mir::*;
-use rustc_hir as hir;
-use rustc_span::symbol::sym;
 
 impl<'a, 'tcx> Builder<'a, 'tcx> {
     /// Compile `expr` into a fresh temporary. This is used when building
@@ -60,7 +59,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 local_decl = local_decl.block_tail(tail_info);
             }
             if let ExprKind::StaticRef { def_id, .. } = expr.kind {
-                let is_thread_local = this.hir.tcx().has_attr(def_id, sym::thread_local);
+                let is_thread_local = this.hir.tcx().is_thread_local_static(def_id);
                 local_decl.internal = true;
                 local_decl.local_info = LocalInfo::StaticRef { def_id, is_thread_local };
             }