Port #[must_not_suspend] to attribute parser

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -47,6 +47,7 @@ pub(crate) mod link_attrs;
 pub(crate) mod lint_helpers;
 pub(crate) mod loop_match;
 pub(crate) mod macro_attrs;
+pub(crate) mod must_not_suspend;
 pub(crate) mod must_use;
 pub(crate) mod no_implicit_prelude;
 pub(crate) mod no_link;

compiler/rustc_attr_parsing/src/attributes/must_not_suspend.rs

@@ -0,0 +1,35 @@
+use super::prelude::*;
+
+pub(crate) struct MustNotSuspendParser;
+
+impl<S: Stage> SingleAttributeParser<S> for MustNotSuspendParser {
+    const PATH: &[rustc_span::Symbol] = &[sym::must_not_suspend];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepInnermost;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::Struct),
+        Allow(Target::Enum),
+        Allow(Target::Union),
+        Allow(Target::Trait),
+    ]);
+    const TEMPLATE: AttributeTemplate = template!(Word, List: &["count"]);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser) -> Option<AttributeKind> {
+        let reason = match args {
+            ArgParser::NameValue(reason) => match reason.value_as_str() {
+                Some(val) => Some(val),
+                None => {
+                    cx.expected_nv_or_no_args(reason.value_span);
+                    return None;
+                }
+            },
+            ArgParser::NoArgs => None,
+            ArgParser::List(list) => {
+                cx.expected_nv_or_no_args(list.span);
+                return None;
+            }
+        };
+
+        Some(AttributeKind::MustNotSupend { reason })
+    }
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -51,6 +51,7 @@ use crate::attributes::macro_attrs::{
     AllowInternalUnsafeParser, CollapseDebugInfoParser, MacroEscapeParser, MacroExportParser,
     MacroUseParser,
 };
+use crate::attributes::must_not_suspend::MustNotSuspendParser;
 use crate::attributes::must_use::MustUseParser;
 use crate::attributes::no_implicit_prelude::NoImplicitPreludeParser;
 use crate::attributes::no_link::NoLinkParser;
@@ -89,7 +90,6 @@ use crate::session_diagnostics::{
     AttributeParseError, AttributeParseErrorReason, ParsedDescription,
 };
 use crate::target_checking::AllowedTargets;
-
 type GroupType<S> = LazyLock<GroupTypeInner<S>>;
 
 pub(super) struct GroupTypeInner<S: Stage> {
@@ -208,6 +208,7 @@ attribute_parsers!(
         Single<LinkageParser>,
         Single<MacroExportParser>,
         Single<MoveSizeLimitParser>,
+        Single<MustNotSuspendParser>,
         Single<MustUseParser>,
         Single<ObjcClassParser>,
         Single<ObjcSelectorParser>,

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -824,6 +824,9 @@ pub enum AttributeKind {
     /// Represents `#[move_size_limit]`
     MoveSizeLimit { attr_span: Span, limit_span: Span, limit: Limit },
 
+    /// Represents `#[must_not_suspend]`
+    MustNotSupend { reason: Option<Symbol> },
+
     /// Represents `#[must_use]`.
     MustUse {
         span: Span,

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -71,6 +71,7 @@ impl AttributeKind {
             Marker(..) => No,
             MayDangle(..) => No,
             MoveSizeLimit { .. } => No,
+            MustNotSupend { .. } => Yes,
             MustUse { .. } => Yes,
             Naked(..) => No,
             NoCore(..) => No,

compiler/rustc_mir_transform/src/coroutine.rs

@@ -64,9 +64,9 @@ use itertools::izip;
 use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::pluralize;
-use rustc_hir as hir;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::{CoroutineDesugaring, CoroutineKind};
+use rustc_hir::{self as hir, CoroutineDesugaring, CoroutineKind, find_attr};
 use rustc_index::bit_set::{BitMatrix, DenseBitSet, GrowableBitSet};
 use rustc_index::{Idx, IndexVec, indexvec};
 use rustc_middle::mir::visit::{MutVisitor, MutatingUseContext, PlaceContext, Visitor};
@@ -85,7 +85,6 @@ use rustc_mir_dataflow::{
 };
 use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::source_map::dummy_spanned;
-use rustc_span::symbol::sym;
 use rustc_span::{DUMMY_SP, Span};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::infer::TyCtxtInferExt as _;
@@ -1989,11 +1988,11 @@ fn check_must_not_suspend_def(
     hir_id: hir::HirId,
     data: SuspendCheckData<'_>,
 ) -> bool {
-    if let Some(attr) = tcx.get_attr(def_id, sym::must_not_suspend) {
-        let reason = attr.value_str().map(|s| errors::MustNotSuspendReason {
-            span: data.source_span,
-            reason: s.as_str().to_string(),
-        });
+    if let Some(reason_str) =
+        find_attr!(tcx.get_all_attrs(def_id), AttributeKind::MustNotSupend {reason} => reason)
+    {
+        let reason =
+            reason_str.map(|s| errors::MustNotSuspendReason { span: data.source_span, reason: s });
         tcx.emit_node_span_lint(
             rustc_session::lint::builtin::MUST_NOT_SUSPEND,
             hir_id,

compiler/rustc_mir_transform/src/errors.rs

@@ -323,7 +323,7 @@ impl<'a> LintDiagnostic<'a, ()> for MustNotSupend<'_, '_> {
 pub(crate) struct MustNotSuspendReason {
     #[primary_span]
     pub span: Span,
-    pub reason: String,
+    pub reason: Symbol,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_passes/messages.ftl

@@ -376,10 +376,6 @@ passes_must_implement_not_function_note = all `#[rustc_must_implement_one_of]` a
 
 passes_must_implement_not_function_span_note = required by this annotation
 
-passes_must_not_suspend =
-    `must_not_suspend` attribute should be applied to a struct, enum, union, or trait
-    .label = is not a struct, enum, union, or trait
-
 passes_no_main_function =
     `main` function not found in crate `{$crate_name}`
     .here_is_main = here is a function named `main`

compiler/rustc_passes/src/check_attr.rs

@@ -308,6 +308,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::ThreadLocal
                     | AttributeKind::CfiEncoding { .. }
                     | AttributeKind::RustcHasIncoherentInherentImpls
+                    | AttributeKind::MustNotSupend { .. }
                 ) => { /* do nothing  */ }
                 Attribute::Unparsed(attr_item) => {
                     style = Some(attr_item.style);
@@ -325,7 +326,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                         | [sym::rustc_dirty, ..]
                         | [sym::rustc_if_this_changed, ..]
                         | [sym::rustc_then_this_would_need, ..] => self.check_rustc_dirty_clean(attr),
-                        [sym::must_not_suspend, ..] => self.check_must_not_suspend(attr, span, target),
                         [sym::autodiff_forward, ..] | [sym::autodiff_reverse, ..] => {
                             self.check_autodiff(hir_id, attr, span, target)
                         }
@@ -1197,16 +1197,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    /// Checks if `#[must_not_suspend]` is applied to a struct, enum, union, or trait.
-    fn check_must_not_suspend(&self, attr: &Attribute, span: Span, target: Target) {
-        match target {
-            Target::Struct | Target::Enum | Target::Union | Target::Trait => {}
-            _ => {
-                self.dcx().emit_err(errors::MustNotSuspend { attr_span: attr.span(), span });
-            }
-        }
-    }
-
     /// Checks if `#[may_dangle]` is applied to a lifetime or type generic parameter in `Drop` impl.
     fn check_may_dangle(&self, hir_id: HirId, attr_span: Span) {
         if let hir::Node::GenericParam(param) = self.tcx.hir_node(hir_id)

compiler/rustc_passes/src/errors.rs

@@ -194,15 +194,6 @@ pub(crate) struct BothFfiConstAndPure {
     pub attr_span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(passes_must_not_suspend)]
-pub(crate) struct MustNotSuspend {
-    #[primary_span]
-    pub attr_span: Span,
-    #[label]
-    pub span: Span,
-}
-
 #[derive(LintDiagnostic)]
 #[diag(passes_link)]
 #[warning]

tests/ui/attributes/malformed-attrs.stderr

@@ -32,21 +32,6 @@ error: malformed `patchable_function_entry` attribute input
 LL | #[patchable_function_entry]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[patchable_function_entry(prefix_nops = m, entry_nops = n)]`
 
-error: malformed `must_not_suspend` attribute input
-  --> $DIR/malformed-attrs.rs:138:1
-   |
-LL | #[must_not_suspend()]
-   | ^^^^^^^^^^^^^^^^^^^^^
-   |
-help: the following are the possible correct uses
-   |
-LL - #[must_not_suspend()]
-LL + #[must_not_suspend = "reason"]
-   |
-LL - #[must_not_suspend()]
-LL + #[must_not_suspend]
-   |
-
 error: malformed `allow` attribute input
   --> $DIR/malformed-attrs.rs:184:1
    |
@@ -527,6 +512,22 @@ LL | #[rustc_layout_scalar_valid_range_end]
    | expected this to be a list
    | help: must be of the form: `#[rustc_layout_scalar_valid_range_end(end)]`
 
+error[E0539]: malformed `must_not_suspend` attribute input
+  --> $DIR/malformed-attrs.rs:138:1
+   |
+LL | #[must_not_suspend()]
+   | ^^^^^^^^^^^^^^^^^^--^
+   |                   |
+   |                   didn't expect a list here
+   |
+help: try changing it to one of the following valid forms of the attribute
+   |
+LL | #[must_not_suspend(count)]
+   |                    +++++
+LL - #[must_not_suspend()]
+LL + #[must_not_suspend]
+   |
+
 error[E0539]: malformed `cfi_encoding` attribute input
   --> $DIR/malformed-attrs.rs:140:1
    |

tests/ui/lint/must_not_suspend/other_items.rs

@@ -2,7 +2,7 @@
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
 
-#[must_not_suspend] //~ ERROR attribute should be
+#[must_not_suspend] //~ ERROR attribute cannot be used on modules
 mod inner {}
 
 fn main() {}

tests/ui/lint/must_not_suspend/other_items.stderr

@@ -1,10 +1,10 @@
-error: `must_not_suspend` attribute should be applied to a struct, enum, union, or trait
+error: `#[must_not_suspend]` attribute cannot be used on modules
   --> $DIR/other_items.rs:5:1
    |
 LL | #[must_not_suspend]
    | ^^^^^^^^^^^^^^^^^^^
-LL | mod inner {}
-   | ------------ is not a struct, enum, union, or trait
+   |
+   = help: `#[must_not_suspend]` can be applied to data types, traits, and unions
 
 error: aborting due to 1 previous error
 

tests/ui/lint/must_not_suspend/return.rs

@@ -2,7 +2,7 @@
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
 
-#[must_not_suspend] //~ ERROR attribute should be
+#[must_not_suspend] //~ ERROR attribute cannot be used on functions
 fn foo() -> i32 {
     0
 }

tests/ui/lint/must_not_suspend/return.stderr

@@ -1,12 +1,10 @@
-error: `must_not_suspend` attribute should be applied to a struct, enum, union, or trait
+error: `#[must_not_suspend]` attribute cannot be used on functions
   --> $DIR/return.rs:5:1
    |
-LL |   #[must_not_suspend]
-   |   ^^^^^^^^^^^^^^^^^^^
-LL | / fn foo() -> i32 {
-LL | |     0
-LL | | }
-   | |_- is not a struct, enum, union, or trait
+LL | #[must_not_suspend]
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+   = help: `#[must_not_suspend]` can be applied to data types, traits, and unions
 
 error: aborting due to 1 previous error