Merge pull request #18746 from lnicola/sync-from-rust

minor: Sync from downstream

6 files changed, 17 insertions, 22 deletions

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
index aef8642f199..2c9f1cda13a 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
@@ -7,7 +7,7 @@ use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_middle::bug;
 use rustc_middle::middle::debugger_visualizer::DebuggerVisualizerType;
 use rustc_session::config::{CrateType, DebugInfo};
-use rustc_span::symbol::sym;
+use rustc_span::sym;
 
 use crate::builder::Builder;
 use crate::common::CodegenCx;
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 59275254022..40248a9009a 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -16,8 +16,7 @@ use rustc_middle::ty::{
     self, AdtKind, CoroutineArgsExt, Instance, PolyExistentialTraitRef, Ty, TyCtxt, Visibility,
 };
 use rustc_session::config::{self, DebugInfo, Lto};
-use rustc_span::symbol::Symbol;
-use rustc_span::{DUMMY_SP, FileName, FileNameDisplayPreference, SourceFile, hygiene};
+use rustc_span::{DUMMY_SP, FileName, FileNameDisplayPreference, SourceFile, Symbol, hygiene};
 use rustc_symbol_mangling::typeid_for_trait_ref;
 use rustc_target::spec::DebuginfoKind;
 use smallvec::smallvec;
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
index d374767f187..23e11748e52 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
@@ -212,21 +212,17 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>(
         ),
         |cx, enum_type_di_node| {
             match enum_type_and_layout.variants {
-                Variants::Single { index: variant_index } => {
-                    if enum_adt_def.variants().is_empty() {
-                        // Uninhabited enums have Variants::Single. We don't generate
-                        // any members for them.
-                        return smallvec![];
-                    }
-
-                    build_single_variant_union_fields(
-                        cx,
-                        enum_adt_def,
-                        enum_type_and_layout,
-                        enum_type_di_node,
-                        variant_index,
-                    )
+                Variants::Empty => {
+                    // We don't generate any members for uninhabited types.
+                    return smallvec![];
                 }
+                Variants::Single { index: variant_index } => build_single_variant_union_fields(
+                    cx,
+                    enum_adt_def,
+                    enum_type_and_layout,
+                    enum_type_di_node,
+                    variant_index,
+                ),
                 Variants::Multiple {
                     tag_encoding: TagEncoding::Direct,
                     ref variants,
@@ -303,6 +299,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
                 )
             }
             Variants::Single { .. }
+            | Variants::Empty
             | Variants::Multiple { tag_encoding: TagEncoding::Niche { .. }, .. } => {
                 bug!(
                     "Encountered coroutine with non-direct-tag layout: {:?}",
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
index 65ab22ad89e..9f6a5cc89e0 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
@@ -392,7 +392,7 @@ fn compute_discriminant_value<'ll, 'tcx>(
     variant_index: VariantIdx,
 ) -> DiscrResult {
     match enum_type_and_layout.layout.variants() {
-        &Variants::Single { .. } => DiscrResult::NoDiscriminant,
+        &Variants::Single { .. } | &Variants::Empty => DiscrResult::NoDiscriminant,
         &Variants::Multiple { tag_encoding: TagEncoding::Direct, .. } => DiscrResult::Value(
             enum_type_and_layout.ty.discriminant_for_variant(cx.tcx, variant_index).unwrap().val,
         ),
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
index 241bf167a81..11824398f24 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
@@ -358,8 +358,8 @@ fn build_discr_member_di_node<'ll, 'tcx>(
     let containing_scope = enum_or_coroutine_type_di_node;
 
     match enum_or_coroutine_type_and_layout.layout.variants() {
-        // A single-variant enum has no discriminant.
-        &Variants::Single { .. } => None,
+        // A single-variant or no-variant enum has no discriminant.
+        &Variants::Single { .. } | &Variants::Empty => None,
 
         &Variants::Multiple { tag_field, .. } => {
             let tag_base_type = tag_base_type(cx.tcx, enum_or_coroutine_type_and_layout);
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index a8fdfbed592..fae698bea2a 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -19,9 +19,8 @@ use rustc_middle::ty::layout::{HasTypingEnv, LayoutOf};
 use rustc_middle::ty::{self, GenericArgsRef, Instance, Ty, TypeVisitableExt};
 use rustc_session::Session;
 use rustc_session::config::{self, DebugInfo};
-use rustc_span::symbol::Symbol;
 use rustc_span::{
-    BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId,
+    BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId, Symbol,
 };
 use smallvec::SmallVec;
 use tracing::debug;