Rollup merge of #135247 - tgross35:stdlib-sym-list, r=oli-obk

Add a list of symbols for stable standard library crates

There are a few locations where the crate name is checked against an enumerated list of `std`, `core`, `alloc`, and `proc_macro`, or some subset thereof. In most cases when we are looking for any "standard library" crate, all four crates should be treated the same. Change this so the crates are listed in one place, and that list is used wherever a list of `std` crates is needed.

`test` could be considered relevant in some of these cases, but generally treating it separate from the others seems preferable while it is unstable.

There are also a few places that Clippy will be able to use this.

5 files changed, 17 insertions, 16 deletions

diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index 91624c7554c..3e3f35332e0 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -18,7 +18,7 @@ use rustc_lint_defs::BuiltinLintDiag;
 use rustc_parse::validate_attr;
 use rustc_session::Session;
 use rustc_session::parse::feature_err;
-use rustc_span::{Span, Symbol, sym};
+use rustc_span::{STDLIB_STABLE_CRATES, Span, Symbol, sym};
 use thin_vec::ThinVec;
 use tracing::instrument;
 
@@ -107,14 +107,11 @@ pub fn features(sess: &Session, krate_attrs: &[Attribute], crate_name: Symbol) -
 
             // If the enabled feature is unstable, record it.
             if UNSTABLE_LANG_FEATURES.iter().find(|f| name == f.name).is_some() {
-                // When the ICE comes from core, alloc or std (approximation of the standard
-                // library), there's a chance that the person hitting the ICE may be using
-                // -Zbuild-std or similar with an untested target. The bug is probably in the
-                // standard library and not the compiler in that case, but that doesn't really
-                // matter - we want a bug report.
-                if features.internal(name)
-                    && ![sym::core, sym::alloc, sym::std].contains(&crate_name)
-                {
+                // When the ICE comes a standard library crate, there's a chance that the person
+                // hitting the ICE may be using -Zbuild-std or similar with an untested target.
+                // The bug is probably in the standard library and not the compiler in that case,
+                // but that doesn't really matter - we want a bug report.
+                if features.internal(name) && !STDLIB_STABLE_CRATES.contains(&crate_name) {
                     sess.using_internal_features.store(true, std::sync::atomic::Ordering::Relaxed);
                 }
 
@@ -133,7 +130,7 @@ pub fn features(sess: &Session, krate_attrs: &[Attribute], crate_name: Symbol) -
 
             // Similar to above, detect internal lib features to suppress
             // the ICE message that asks for a report.
-            if features.internal(name) && ![sym::core, sym::alloc, sym::std].contains(&crate_name) {
+            if features.internal(name) && !STDLIB_STABLE_CRATES.contains(&crate_name) {
                 sess.using_internal_features.store(true, std::sync::atomic::Ordering::Relaxed);
             }
         }
diff --git a/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs b/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs
index 5ccfcf93f69..69d7a6c97cb 100644
--- a/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs
+++ b/compiler/rustc_hir_typeck/src/method/prelude_edition_lints.rs
@@ -8,7 +8,7 @@ use rustc_lint::{ARRAY_INTO_ITER, BOXED_SLICE_INTO_ITER};
 use rustc_middle::span_bug;
 use rustc_middle::ty::{self, Ty};
 use rustc_session::lint::builtin::{RUST_2021_PRELUDE_COLLISIONS, RUST_2024_PRELUDE_COLLISIONS};
-use rustc_span::{Ident, Span, kw, sym};
+use rustc_span::{Ident, STDLIB_STABLE_CRATES, Span, kw, sym};
 use rustc_trait_selection::infer::InferCtxtExt;
 use tracing::debug;
 
@@ -76,7 +76,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
 
         // No need to lint if method came from std/core, as that will now be in the prelude
-        if matches!(self.tcx.crate_name(pick.item.def_id.krate), sym::std | sym::core) {
+        if STDLIB_STABLE_CRATES.contains(&self.tcx.crate_name(pick.item.def_id.krate)) {
             return;
         }
 
@@ -252,7 +252,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         // No need to lint if method came from std/core, as that will now be in the prelude
-        if matches!(self.tcx.crate_name(pick.item.def_id.krate), sym::std | sym::core) {
+        if STDLIB_STABLE_CRATES.contains(&self.tcx.crate_name(pick.item.def_id.krate)) {
             return;
         }
 
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index d5c2a337b4c..51cfbf59471 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -67,7 +67,7 @@ mod span_encoding;
 pub use span_encoding::{DUMMY_SP, Span};
 
 pub mod symbol;
-pub use symbol::{Ident, MacroRulesNormalizedIdent, Symbol, kw, sym};
+pub use symbol::{Ident, MacroRulesNormalizedIdent, STDLIB_STABLE_CRATES, Symbol, kw, sym};
 
 mod analyze_source_file;
 pub mod fatal_error;
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 0dcf38e3493..ef1e2c20978 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -2240,6 +2240,10 @@ symbols! {
     }
 }
 
+/// Symbols for crates that are part of the stable standard library: `std`, `core`, `alloc`, and
+/// `proc_macro`.
+pub const STDLIB_STABLE_CRATES: &[Symbol] = &[sym::std, sym::core, sym::alloc, sym::proc_macro];
+
 #[derive(Copy, Clone, Eq, HashStable_Generic, Encodable, Decodable)]
 pub struct Ident {
     pub name: Symbol,
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index 7ba87e180d0..405c26b5b3b 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -27,7 +27,7 @@ use rustc_middle::ty::{
     self, ToPolyTraitRef, TraitRef, Ty, TyCtxt, TypeFoldable, TypeVisitableExt, Upcast,
 };
 use rustc_middle::{bug, span_bug};
-use rustc_span::{BytePos, DUMMY_SP, Span, Symbol, sym};
+use rustc_span::{BytePos, DUMMY_SP, STDLIB_STABLE_CRATES, Span, Symbol, sym};
 use tracing::{debug, instrument};
 
 use super::on_unimplemented::{AppendConstMessage, OnUnimplementedNote};
@@ -520,7 +520,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                             match obligation.cause.span.ctxt().outer_expn_data().macro_def_id {
                                 Some(macro_def_id) => {
                                     let crate_name = tcx.crate_name(macro_def_id.krate);
-                                    crate_name == sym::std || crate_name == sym::core
+                                    STDLIB_STABLE_CRATES.contains(&crate_name)
                                 }
                                 None => false,
                             };