Don't inject compiler_builtins in the AST

Author: tgross35

compiler/rustc_builtin_macros/src/standard_library_imports.rs

@@ -19,16 +19,12 @@ pub fn inject(
     let edition = sess.psess.edition;
 
     // the first name in this list is the crate name of the crate with the prelude
-    let names: &[Symbol] = if attr::contains_name(pre_configured_attrs, sym::no_core) {
+    let name: Symbol = if attr::contains_name(pre_configured_attrs, sym::no_core) {
         return 0;
     } else if attr::contains_name(pre_configured_attrs, sym::no_std) {
-        if attr::contains_name(pre_configured_attrs, sym::compiler_builtins) {
-            &[sym::core]
-        } else {
-            &[sym::core, sym::compiler_builtins]
-        }
+        sym::core
     } else {
-        &[sym::std]
+        sym::std
     };
 
     let expn_id = resolver.expansion_for_ast_pass(
@@ -43,37 +39,18 @@ pub fn inject(
     let ecfg = ExpansionConfig::default("std_lib_injection".to_string(), features);
     let cx = ExtCtxt::new(sess, ecfg, resolver, None);
 
-    // .rev() to preserve ordering above in combination with insert(0, ...)
-    for &name in names.iter().rev() {
-        let ident_span = if edition >= Edition2018 { span } else { call_site };
-        let item = if name == sym::compiler_builtins {
-            // compiler_builtins is a private implementation detail. We only
-            // need to insert it into the crate graph for linking and should not
-            // expose any of its public API.
-            //
-            // FIXME(#113634) We should inject this during post-processing like
-            // we do for the panic runtime, profiler runtime, etc.
-            cx.item(
-                span,
-                Ident::new(kw::Underscore, ident_span),
-                thin_vec![],
-                ast::ItemKind::ExternCrate(Some(name)),
-            )
-        } else {
-            cx.item(
-                span,
-                Ident::new(name, ident_span),
-                thin_vec![cx.attr_word(sym::macro_use, span)],
-                ast::ItemKind::ExternCrate(None),
-            )
-        };
-        krate.items.insert(0, item);
-    }
+    let ident_span = if edition >= Edition2018 { span } else { call_site };
 
-    // The crates have been injected, the assumption is that the first one is
-    // the one with the prelude.
-    let name = names[0];
+    let item = cx.item(
+        span,
+        Ident::new(name, ident_span),
+        thin_vec![cx.attr_word(sym::macro_use, span)],
+        ast::ItemKind::ExternCrate(None),
+    );
+
+    krate.items.insert(0, item);
 
+    // Inject the relevant crate's prelude.
     let root = (edition == Edition2015).then_some(kw::PathRoot);
 
     let import_path = root

compiler/rustc_metadata/src/creader.rs

@@ -1213,11 +1213,6 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
                     CrateDepKind::Explicit
                 };
 
-                if name == sym::compiler_builtins {
-                    info!("BUILTINS DETECTED dep_kind {dep_kind:?}");
-                    return None;
-                }
-
                 let cnum = self.resolve_crate(name, item.span, dep_kind, CrateOrigin::AstExtern)?;
 
                 let path_len = definitions.def_path(def_id).data.len();

compiler/rustc_middle/src/middle/stability.rs

@@ -408,6 +408,7 @@ impl<'tcx> TyCtxt<'tcx> {
                 inspecting def_id={:?} span={:?} of stability={:?}",
             def_id, span, stability
         );
+        tracing::info!("stability table: {:#?}", self.stability());
 
         match stability {
             Some(Stability {