Add error for invalid item of instruction_set

Author: chansuke

compiler/rustc_passes/messages.ftl

@@ -112,6 +112,10 @@ passes_coroutine_on_non_closure =
     attribute should be applied to closures
     .label = not a closure
 
+passes_invalid_instruction_set =
+    `[instruction_set]` attribute argument should be valid
+    .label = `[instruction_set]` containes invalid argument
+
 passes_coverage_not_fn_or_closure =
     attribute should be applied to a function definition or closure
     .label = not a function or closure

compiler/rustc_passes/src/check_attr.rs

@@ -4,11 +4,10 @@
 //! conflicts between multiple such attributes attached to the same
 //! item.
 
-use std::cell::Cell;
-use std::collections::hash_map::Entry;
-
 use rustc_ast::{
     AttrKind, AttrStyle, Attribute, LitKind, MetaItemInner, MetaItemKind, MetaItemLit, ast,
+    token::TokenKind, tokenstream::TokenTree, AttrKind, AttrStyle, Attribute, LitKind,
+    MetaItemKind, MetaItemLit, NestedMetaItem,
 };
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, DiagCtxtHandle, IntoDiagArg, MultiSpan, StashKey};
@@ -39,6 +38,8 @@ use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::infer::{TyCtxtInferExt, ValuePairs};
 use rustc_trait_selection::traits::ObligationCtxt;
+use std::cell::Cell;
+use std::collections::hash_map::Entry;
 use tracing::debug;
 
 use crate::{errors, fluent_generated as fluent};
@@ -249,6 +250,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 }
                 [sym::linkage, ..] => self.check_linkage(attr, span, target),
                 [sym::rustc_pub_transparent, ..] => self.check_rustc_pub_transparent( attr.span, span, attrs),
+                [sym::instruction_set, ..] => {
+                    self.check_instruction_set(attr, item);
+                }
                 [
                     // ok
                     sym::allow
@@ -264,7 +268,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | sym::omit_gdb_pretty_printer_section // FIXME(omit_gdb_pretty_printer_section)
                     | sym::used // handled elsewhere to restrict to static items
                     | sym::repr // handled elsewhere to restrict to type decls items
-                    | sym::instruction_set // broken on stable!!!
                     | sym::windows_subsystem // broken on stable!!!
                     | sym::patchable_function_entry // FIXME(patchable_function_entry)
                     | sym::deprecated_safe // FIXME(deprecated_safe)
@@ -2398,6 +2401,37 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
             _ => {
                 self.dcx().emit_err(errors::AutoDiffAttr { attr_span: span });
                 self.abort.set(true);
+        }
+    }
+
+    fn check_instruction_set(&self, attr: &Attribute, _item: Option<ItemLike<'_>>) {
+        if let AttrKind::Normal(ref p) = attr.kind {
+            let inner_tokens = p.item.args.inner_tokens();
+            let mut tokens = inner_tokens.trees();
+
+            // Valid item for `instruction_set()` is:
+            // - arm::a32
+            // - arm::t32
+            let valid_attribute = match (tokens.next(), tokens.next(), tokens.next()) {
+                (
+                    Some(TokenTree::Token(first_token, _)),
+                    Some(TokenTree::Token(second_token, _)),
+                    Some(TokenTree::Token(third_token, _)),
+                ) => match (first_token.ident(), second_token.kind.clone(), third_token.ident()) {
+                    (Some(first_ident), TokenKind::PathSep, Some(third_ident))
+                        if first_ident.0.name == sym::arm =>
+                    {
+                        third_ident.0.name == sym::a32 || third_ident.0.name == sym::t32
+                    }
+                    _ => false,
+                },
+                _ => false,
+            };
+
+            if !valid_attribute {
+                self.dcx().emit_err(errors::InvalidInstructionSet { span: attr.span });
+            } else {
+                return;
             }
         }
     }

compiler/rustc_passes/src/errors.rs

@@ -10,7 +10,7 @@ use rustc_errors::{
 use rustc_hir::{self as hir, ExprKind, Target};
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::{MainDefinition, Ty};
-use rustc_span::{DUMMY_SP, Span, Symbol};
+use rustc_span::{Span, Symbol, DUMMY_SP};
 
 use crate::check_attr::ProcMacroKind;
 use crate::fluent_generated as fluent;
@@ -693,6 +693,13 @@ pub(crate) struct Linkage {
     #[primary_span]
     pub attr_span: Span,
     #[label]
+    #[label]
+    pub span: Span,
+}
+
+#[diag(passes_invalid_instruction_set)]
+pub struct InvalidInstructionSet {
+    #[primary_span]
     pub span: Span,
 }
 
@@ -1363,11 +1370,15 @@ pub(crate) struct DuplicateLangItem {
 impl<G: EmissionGuarantee> Diagnostic<'_, G> for DuplicateLangItem {
     #[track_caller]
     fn into_diag(self, dcx: DiagCtxtHandle<'_>, level: Level) -> Diag<'_, G> {
-        let mut diag = Diag::new(dcx, level, match self.duplicate {
-            Duplicate::Plain => fluent::passes_duplicate_lang_item,
-            Duplicate::Crate => fluent::passes_duplicate_lang_item_crate,
-            Duplicate::CrateDepends => fluent::passes_duplicate_lang_item_crate_depends,
-        });
+        let mut diag = Diag::new(
+            dcx,
+            level,
+            match self.duplicate {
+                Duplicate::Plain => fluent::passes_duplicate_lang_item,
+                Duplicate::Crate => fluent::passes_duplicate_lang_item_crate,
+                Duplicate::CrateDepends => fluent::passes_duplicate_lang_item_crate_depends,
+            },
+        );
         diag.code(E0152);
         diag.arg("lang_item_name", self.lang_item_name);
         diag.arg("crate_name", self.crate_name);

tests/ui/attributes/instruction-set.rs

@@ -0,0 +1,21 @@
+#![feature(stmt_expr_attributes)]
+
+#[instruction_set(arm::a32)]
+type ValidA = ();
+
+#[instruction_set(arm::t32)]
+type ValidB = ();
+
+#[instruction_set(asdfasdf)] //~ ERROR `[instruction_set]` attribute argument should be valid
+type InvalidA = ();
+
+#[instruction_set(asdfasdf)] //~ ERROR `[instruction_set]` attribute argument should be valid
+mod InvalidB {}
+
+#[instruction_set(asdfasdf)] //~ ERROR `[instruction_set]` attribute argument should be valid
+struct InvalidC;
+
+#[instruction_set(asdfasdf)] //~ ERROR `[instruction_set]` attribute argument should be valid
+impl InvalidC {}
+
+fn main() {}

tests/ui/attributes/instruction-set.stderr

@@ -0,0 +1,26 @@
+error: `[instruction_set]` attribute argument should be valid
+  --> $DIR/instruction-set.rs:9:1
+   |
+LL | #[instruction_set(asdfasdf)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `[instruction_set]` attribute argument should be valid
+  --> $DIR/instruction-set.rs:12:1
+   |
+LL | #[instruction_set(asdfasdf)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `[instruction_set]` attribute argument should be valid
+  --> $DIR/instruction-set.rs:15:1
+   |
+LL | #[instruction_set(asdfasdf)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `[instruction_set]` attribute argument should be valid
+  --> $DIR/instruction-set.rs:18:1
+   |
+LL | #[instruction_set(asdfasdf)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 4 previous errors
+