Port #[ffi_pure] to the new attribute system

Author: GrigorenkoPV

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -254,6 +254,9 @@ pub enum AttributeKind {
     /// Represents `#[ffi_const]`.
     FfiConst(Span),
 
+    /// Represents `#[ffi_pure]`.
+    FfiPure(Span),
+
     /// Represents `#[ignore]`
     Ignore {
         span: Span,

compiler/rustc_attr_data_structures/src/encode_cross_crate.rs

@@ -28,6 +28,7 @@ impl AttributeKind {
             ExportName { .. } => Yes,
             ExportStable => No,
             FfiConst(..) => No,
+            FfiPure(..) => No,
             Ignore { .. } => No,
             Inline(..) => No,
             LinkName { .. } => Yes,

compiler/rustc_attr_parsing/src/attributes/link_attrs.rs

@@ -73,3 +73,10 @@ impl<S: Stage> NoArgsAttributeParser<S> for FfiConstParser {
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::FfiConst;
 }
+
+pub(crate) struct FfiPureParser;
+impl<S: Stage> NoArgsAttributeParser<S> for FfiPureParser {
+    const PATH: &[Symbol] = &[sym::ffi_pure];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Warn;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::FfiPure;
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -23,7 +23,7 @@ use crate::attributes::confusables::ConfusablesParser;
 use crate::attributes::deprecation::DeprecationParser;
 use crate::attributes::inline::{InlineParser, RustcForceInlineParser};
 use crate::attributes::link_attrs::{
-    ExportStableParser, FfiConstParser, LinkNameParser, LinkSectionParser,
+    ExportStableParser, FfiConstParser, FfiPureParser, LinkNameParser, LinkSectionParser,
 };
 use crate::attributes::lint_helpers::{AsPtrParser, PassByValueParser, PubTransparentParser};
 use crate::attributes::loop_match::{ConstContinueParser, LoopMatchParser};
@@ -149,6 +149,7 @@ attribute_parsers!(
         Single<WithoutArgs<ConstStabilityIndirectParser>>,
         Single<WithoutArgs<ExportStableParser>>,
         Single<WithoutArgs<FfiConstParser>>,
+        Single<WithoutArgs<FfiPureParser>>,
         Single<WithoutArgs<LoopMatchParser>>,
         Single<WithoutArgs<MayDangleParser>>,
         Single<WithoutArgs<NoImplicitPreludeParser>>,

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -206,6 +206,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                 AttributeKind::FfiConst(_) => {
                     codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_CONST
                 }
+                AttributeKind::FfiPure(_) => codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE,
                 _ => {}
             }
         }
@@ -216,7 +217,6 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
 
         match name {
             sym::rustc_allocator => codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR,
-            sym::ffi_pure => codegen_fn_attrs.flags |= CodegenFnAttrFlags::FFI_PURE,
             sym::rustc_nounwind => codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND,
             sym::rustc_reallocator => codegen_fn_attrs.flags |= CodegenFnAttrFlags::REALLOCATOR,
             sym::rustc_deallocator => codegen_fn_attrs.flags |= CodegenFnAttrFlags::DEALLOCATOR,

compiler/rustc_parse/src/validate_attr.rs

@@ -273,6 +273,7 @@ pub fn check_builtin_meta_item(
             sym::inline
                 | sym::export_stable
                 | sym::ffi_const
+                | sym::ffi_pure
                 | sym::may_dangle
                 | sym::rustc_as_ptr
                 | sym::rustc_pub_transparent

compiler/rustc_passes/src/check_attr.rs

@@ -210,6 +210,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 &Attribute::Parsed(AttributeKind::FfiConst(attr_span)) => {
                     self.check_ffi_const(attr_span, target)
                 }
+                &Attribute::Parsed(AttributeKind::FfiPure(attr_span)) => {
+                    self.check_ffi_pure(attr_span, attrs, target)
+                }
                 Attribute::Parsed(
                     AttributeKind::BodyStability { .. }
                     | AttributeKind::ConstStabilityIndirect
@@ -306,7 +309,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                         [sym::rustc_has_incoherent_inherent_impls, ..] => {
                             self.check_has_incoherent_inherent_impls(attr, span, target)
                         }
-                        [sym::ffi_pure, ..] => self.check_ffi_pure(attr.span(), attrs, target),
                         [sym::link_ordinal, ..] => self.check_link_ordinal(attr, span, target),
                         [sym::link, ..] => self.check_link(hir_id, attr, span, target),
                         [sym::macro_use, ..] | [sym::macro_escape, ..] => {

tests/ui/attributes/malformed-attrs.stderr

@@ -134,12 +134,6 @@ error: malformed `fundamental` attribute input
 LL | #[fundamental()]
    | ^^^^^^^^^^^^^^^^ help: must be of the form: `#[fundamental]`
 
-error: malformed `ffi_pure` attribute input
-  --> $DIR/malformed-attrs.rs:165:5
-   |
-LL |     #[unsafe(ffi_pure = 1)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^ help: must be of the form: `#[ffi_pure]`
-
 error: malformed `link_ordinal` attribute input
   --> $DIR/malformed-attrs.rs:167:5
    |
@@ -534,6 +528,15 @@ 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[E0565]: malformed `ffi_pure` attribute input
+  --> $DIR/malformed-attrs.rs:165:5
+   |
+LL |     #[unsafe(ffi_pure = 1)]
+   |     ^^^^^^^^^^^^^^^^^^---^^
+   |     |                 |
+   |     |                 didn't expect any arguments here
+   |     help: must be of the form: `#[ffi_pure]`
+
 error[E0565]: malformed `ffi_const` attribute input
   --> $DIR/malformed-attrs.rs:171:5
    |