Remove artificial flag from generator variants

- Literally, variants are not artificial. We have `yield` statements, upvars and inner variables in the source code. - Functionally, we don't want debuggers to suppress the variants. It contains the state of the generator, which is useful when debugging. So they shouldn't be marked artificial. - Debuggers may use artificial flags to find the active variant. In this case, marking variants artificial will make debuggers not work properly. Fixes rust-lang#79009.
Dylan-DPC-zz · Apr 30, 2021 · 5bf989e · 5bf989e
1 parent 060deec
commit 5bf989e
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diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1495,10 +1495,6 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
         } else {
             type_metadata(cx, self.enum_type, self.span)
         };
-        let flags = match self.enum_type.kind() {
-            ty::Generator(..) => DIFlags::FlagArtificial,
-            _ => DIFlags::FlagZero,
-        };
 
         match self.layout.variants {
             Variants::Single { index } => {
@@ -1533,7 +1529,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                     offset: Size::ZERO,
                     size: self.layout.size,
                     align: self.layout.align.abi,
-                    flags,
+                    flags: DIFlags::FlagZero,
                     discriminant: None,
                     source_info: variant_info.source_info(cx),
                 }]
@@ -1588,7 +1584,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                             offset: Size::ZERO,
                             size: self.layout.size,
                             align: self.layout.align.abi,
-                            flags,
+                            flags: DIFlags::FlagZero,
                             discriminant: Some(
                                 self.layout.ty.discriminant_for_variant(cx.tcx, i).unwrap().val
                                     as u64,
@@ -1672,7 +1668,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                         offset: Size::ZERO,
                         size: variant.size,
                         align: variant.align.abi,
-                        flags,
+                        flags: DIFlags::FlagZero,
                         discriminant: None,
                         source_info: variant_info.source_info(cx),
                     }]
@@ -1723,7 +1719,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
                                 offset: Size::ZERO,
                                 size: self.layout.size,
                                 align: self.layout.align.abi,
-                                flags,
+                                flags: DIFlags::FlagZero,
                                 discriminant: niche_value,
                                 source_info: variant_info.source_info(cx),
                             }
@@ -1855,13 +1851,6 @@ impl<'tcx> VariantInfo<'_, 'tcx> {
         }
         None
     }
-
-    fn is_artificial(&self) -> bool {
-        match self {
-            VariantInfo::Generator { .. } => true,
-            VariantInfo::Adt(..) => false,
-        }
-    }
 }
 
 /// Returns a tuple of (1) `type_metadata_stub` of the variant, (2) a
@@ -1887,8 +1876,7 @@ fn describe_enum_variant(
             &variant_name,
             unique_type_id,
             Some(containing_scope),
-            // FIXME(tmandry): This doesn't seem to have any effect.
-            if variant.is_artificial() { DIFlags::FlagArtificial } else { DIFlags::FlagZero },
+            DIFlags::FlagZero,
         )
     });
 
@@ -1951,11 +1939,6 @@ fn prepare_enum_metadata(
 ) -> RecursiveTypeDescription<'ll, 'tcx> {
     let tcx = cx.tcx;
     let enum_name = compute_debuginfo_type_name(tcx, enum_type, false);
-    // FIXME(tmandry): This doesn't seem to have any effect.
-    let enum_flags = match enum_type.kind() {
-        ty::Generator(..) => DIFlags::FlagArtificial,
-        _ => DIFlags::FlagZero,
-    };
 
     let containing_scope = get_namespace_for_item(cx, enum_def_id);
     // FIXME: This should emit actual file metadata for the enum, but we
@@ -2088,7 +2071,7 @@ fn prepare_enum_metadata(
                     UNKNOWN_LINE_NUMBER,
                     layout.size.bits(),
                     layout.align.abi.bits() as u32,
-                    enum_flags,
+                    DIFlags::FlagZero,
                     None,
                     0, // RuntimeLang
                     unique_type_id_str.as_ptr().cast(),
@@ -2210,7 +2193,7 @@ fn prepare_enum_metadata(
             UNKNOWN_LINE_NUMBER,
             layout.size.bits(),
             layout.align.abi.bits() as u32,
-            enum_flags,
+            DIFlags::FlagZero,
             discriminator_metadata,
             empty_array,
             variant_part_unique_type_id_str.as_ptr().cast(),
@@ -2239,7 +2222,7 @@ fn prepare_enum_metadata(
                 UNKNOWN_LINE_NUMBER,
                 layout.size.bits(),
                 layout.align.abi.bits() as u32,
-                enum_flags,
+                DIFlags::FlagZero,
                 None,
                 type_array,
                 0,

diff --git a/src/test/codegen/async-fn-debug-msvc.rs b/src/test/codegen/async-fn-debug-msvc.rs
@@ -1,7 +1,7 @@
 // Verify debuginfo for generators:
 //  - Each variant points to the file and line of its yield point
-//  - The generator types and variants are marked artificial
-//  - Captured vars from the source are not marked artificial
+//  - The discriminants are marked artificial
+//  - Other fields are not marked artificial
 //
 //
 // compile-flags: -C debuginfo=2 --edition=2018
@@ -17,26 +17,32 @@ async fn async_fn_test() {
 // FIXME: No way to reliably check the filename.
 
 // CHECK-DAG:  [[ASYNC_FN:!.*]] = !DINamespace(name: "async_fn_test"
-// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_union_type, name: "generator-0", scope: [[ASYNC_FN]], {{.*}}flags: DIFlagArtificial
+// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_union_type, name: "generator-0", scope: [[ASYNC_FN]]
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // For brevity, we only check the struct name and members of the last variant.
 // CHECK-SAME: file: [[FILE:![0-9]*]], line: 11,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 15,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 15,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 12,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 14,
 // CHECK-SAME: baseType: [[VARIANT:![0-9]*]]
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      [[S1:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Suspend1", scope: [[ASYNC_FN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "RUST$ENUM$DISR", scope: [[S1]],
 // CHECK-SAME: flags: DIFlagArtificial
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "s", scope: [[S1]]

diff --git a/src/test/codegen/async-fn-debug.rs b/src/test/codegen/async-fn-debug.rs
@@ -1,7 +1,7 @@
 // Verify debuginfo for async fn:
 //  - Each variant points to the file and line of its yield point
-//  - The generator types and variants are marked artificial
-//  - Captured vars from the source are not marked artificial
+//  - The discriminants are marked artificial
+//  - Other fields are not marked artificial
 //
 //
 // compile-flags: -C debuginfo=2 --edition=2018
@@ -17,29 +17,36 @@ async fn async_fn_test() {
 // FIXME: No way to reliably check the filename.
 
 // CHECK-DAG:  [[ASYNC_FN:!.*]] = !DINamespace(name: "async_fn_test"
-// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "generator-0", scope: [[ASYNC_FN]], {{.*}}flags: DIFlagArtificial
+// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "generator-0", scope: [[ASYNC_FN]]
 // CHECK:      [[VARIANT:!.*]] = !DICompositeType(tag: DW_TAG_variant_part, scope: [[ASYNC_FN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
 // CHECK-SAME: discriminator: [[DISC:![0-9]*]]
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "0", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE:![0-9]*]], line: 11,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DICompositeType(tag: DW_TAG_structure_type, name: "Unresumed", scope: [[GEN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "1", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 15,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "2", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 15,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "3", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 12,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "4", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 14,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      [[S1:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Suspend1", scope: [[GEN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "s", scope: [[S1]]
 // CHECK-NOT:  flags: DIFlagArtificial
 // CHECK-SAME: )

diff --git a/src/test/codegen/generator-debug-msvc.rs b/src/test/codegen/generator-debug-msvc.rs
@@ -1,7 +1,7 @@
 // Verify debuginfo for generators:
 //  - Each variant points to the file and line of its yield point
-//  - The generator types and variants are marked artificial
-//  - Captured vars from the source are not marked artificial
+//  - The discriminants are marked artificial
+//  - Other fields are not marked artificial
 //
 //
 // compile-flags: -C debuginfo=2
@@ -21,26 +21,32 @@ fn generator_test() -> impl Generator<Yield = i32, Return = ()> {
 // FIXME: No way to reliably check the filename.
 
 // CHECK-DAG:  [[GEN_FN:!.*]] = !DINamespace(name: "generator_test"
-// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_union_type, name: "generator-0", scope: [[GEN_FN]], {{.*}}flags: DIFlagArtificial
+// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_union_type, name: "generator-0", scope: [[GEN_FN]]
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // For brevity, we only check the struct name and members of the last variant.
 // CHECK-SAME: file: [[FILE:![0-9]*]], line: 14,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 18,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 18,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 15,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, scope: [[GEN]],
 // CHECK-SAME: file: [[FILE]], line: 17,
 // CHECK-SAME: baseType: [[VARIANT:![0-9]*]]
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      [[S1:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Suspend1", scope: [[GEN_FN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "RUST$ENUM$DISR", scope: [[S1]],
 // CHECK-SAME: flags: DIFlagArtificial
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "s", scope: [[S1]]

diff --git a/src/test/codegen/generator-debug.rs b/src/test/codegen/generator-debug.rs
@@ -1,7 +1,7 @@
 // Verify debuginfo for generators:
 //  - Each variant points to the file and line of its yield point
-//  - The generator types and variants are marked artificial
-//  - Captured vars from the source are not marked artificial
+//  - The discriminants are marked artificial
+//  - Other fields are not marked artificial
 //
 //
 // compile-flags: -C debuginfo=2 --edition=2018
@@ -21,29 +21,36 @@ fn generator_test() -> impl Generator<Yield = i32, Return = ()> {
 // FIXME: No way to reliably check the filename.
 
 // CHECK-DAG:  [[GEN_FN:!.*]] = !DINamespace(name: "generator_test"
-// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "generator-0", scope: [[GEN_FN]], {{.*}}flags: DIFlagArtificial
+// CHECK-DAG:  [[GEN:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "generator-0", scope: [[GEN_FN]]
 // CHECK:      [[VARIANT:!.*]] = !DICompositeType(tag: DW_TAG_variant_part, scope: [[GEN_FN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
 // CHECK-SAME: discriminator: [[DISC:![0-9]*]]
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "0", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE:![0-9]*]], line: 14,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DICompositeType(tag: DW_TAG_structure_type, name: "Unresumed", scope: [[GEN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "1", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 18,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "2", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 18,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "3", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 15,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "4", scope: [[VARIANT]],
 // CHECK-SAME: file: [[FILE]], line: 17,
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      [[S1:!.*]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Suspend1", scope: [[GEN]],
-// CHECK-SAME: flags: DIFlagArtificial
+// CHECK-NOT:  flags: DIFlagArtificial
+// CHECK-SAME: )
 // CHECK:      {{!.*}} = !DIDerivedType(tag: DW_TAG_member, name: "s", scope: [[S1]]
 // CHECK-NOT:  flags: DIFlagArtificial
 // CHECK-SAME: )

diff --git a/src/test/debuginfo/generator-objects.rs b/src/test/debuginfo/generator-objects.rs
@@ -1,22 +1,26 @@
 // Require a gdb that can read DW_TAG_variant_part.
 // min-gdb-version: 8.2
 
+// LLDB without native Rust support cannot read DW_TAG_variant_part,
+// so it prints nothing for generators. But those tests are kept to
+// ensure that LLDB won't crash at least (like #57822).
+
 // compile-flags:-g
 
 // === GDB TESTS ===================================================================================
 
 // gdb-command:run
 // gdb-command:print b
-// gdb-check:$1 = <error reading variable>
+// gdb-check:$1 = generator_objects::main::generator-0::Unresumed(0x[...])
 // gdb-command:continue
 // gdb-command:print b
-// gdb-check:$2 = <error reading variable>
+// gdb-check:$2 = generator_objects::main::generator-0::Suspend0{c: 6, d: 7, __0: 0x[...]}
 // gdb-command:continue
 // gdb-command:print b
-// gdb-check:$3 = <error reading variable>
+// gdb-check:$3 = generator_objects::main::generator-0::Suspend1{c: 7, d: 8, __0: 0x[...]}
 // gdb-command:continue
 // gdb-command:print b
-// gdb-check:$4 = <error reading variable>
+// gdb-check:$4 = generator_objects::main::generator-0::Returned(0x[...])
 
 // === LLDB TESTS ==================================================================================
 

diff --git a/src/test/debuginfo/issue-57822.rs b/src/test/debuginfo/issue-57822.rs
@@ -14,7 +14,7 @@
 // gdb-check:$1 = issue_57822::main::closure-1 (issue_57822::main::closure-0 (1))
 
 // gdb-command:print b
-// gdb-check:$2 = <error reading variable>
+// gdb-check:$2 = issue_57822::main::generator-3::Unresumed(issue_57822::main::generator-2::Unresumed(2))
 
 // === LLDB TESTS ==================================================================================