Rollup merge of rust-lang#80870 - petrochenkov:bmactable, r=oli-obk

resolve: Simplify built-in macro table

We don't use full `SyntaxExtension`s from the table, only `SyntaxExtensionKind`s, and `Ident` in `register_builtin_macro` always had dummy span. This PR removes unnecessary data from the table and related function signatures.

Noticed when reviewing rust-lang#80850.

Author: JohnTitor

compiler/rustc_builtin_macros/src/lib.rs

@@ -14,10 +14,9 @@ extern crate proc_macro;
 
 use crate::deriving::*;
 
-use rustc_expand::base::{MacroExpanderFn, ResolverExpand, SyntaxExtension, SyntaxExtensionKind};
+use rustc_expand::base::{MacroExpanderFn, ResolverExpand, SyntaxExtensionKind};
 use rustc_expand::proc_macro::BangProcMacro;
-use rustc_span::edition::Edition;
-use rustc_span::symbol::{sym, Ident};
+use rustc_span::symbol::sym;
 
 mod asm;
 mod assert;
@@ -44,13 +43,8 @@ pub mod proc_macro_harness;
 pub mod standard_library_imports;
 pub mod test_harness;
 
-pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand, edition: Edition) {
-    let mut register = |name, kind| {
-        resolver.register_builtin_macro(
-            Ident::with_dummy_span(name),
-            SyntaxExtension::default(kind, edition),
-        )
-    };
+pub fn register_builtin_macros(resolver: &mut dyn ResolverExpand) {
+    let mut register = |name, kind| resolver.register_builtin_macro(name, kind);
     macro register_bang($($name:ident: $f:expr,)*) {
         $(register(sym::$name, SyntaxExtensionKind::LegacyBang(Box::new($f as MacroExpanderFn)));)*
     }

compiler/rustc_expand/src/base.rs

@@ -868,7 +868,7 @@ pub trait ResolverExpand {
 
     fn resolve_dollar_crates(&mut self);
     fn visit_ast_fragment_with_placeholders(&mut self, expn_id: ExpnId, fragment: &AstFragment);
-    fn register_builtin_macro(&mut self, ident: Ident, ext: SyntaxExtension);
+    fn register_builtin_macro(&mut self, name: Symbol, ext: SyntaxExtensionKind);
 
     fn expansion_for_ast_pass(
         &mut self,

compiler/rustc_interface/src/passes.rs

@@ -236,7 +236,7 @@ fn configure_and_expand_inner<'a>(
     pre_expansion_lint(sess, lint_store, &krate);
 
     let mut resolver = Resolver::new(sess, &krate, crate_name, metadata_loader, &resolver_arenas);
-    rustc_builtin_macros::register_builtin_macros(&mut resolver, sess.edition());
+    rustc_builtin_macros::register_builtin_macros(&mut resolver);
 
     krate = sess.time("crate_injection", || {
         let alt_std_name = sess.opts.alt_std_name.as_ref().map(|s| Symbol::intern(s));

compiler/rustc_resolve/src/lib.rs

@@ -33,7 +33,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_data_structures::ptr_key::PtrKey;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
-use rustc_expand::base::SyntaxExtension;
+use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
 use rustc_hir::def::Namespace::*;
 use rustc_hir::def::{self, CtorOf, DefKind, NonMacroAttrKind, PartialRes};
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX};
@@ -874,7 +874,7 @@ pub struct ExternPreludeEntry<'a> {
 
 /// Used for better errors for E0773
 enum BuiltinMacroState {
-    NotYetSeen(SyntaxExtension),
+    NotYetSeen(SyntaxExtensionKind),
     AlreadySeen(Span),
 }
 

compiler/rustc_resolve/src/macros.rs

@@ -14,7 +14,8 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::ptr_key::PtrKey;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::struct_span_err;
-use rustc_expand::base::{Indeterminate, InvocationRes, ResolverExpand, SyntaxExtension};
+use rustc_expand::base::{Indeterminate, InvocationRes, ResolverExpand};
+use rustc_expand::base::{SyntaxExtension, SyntaxExtensionKind};
 use rustc_expand::compile_declarative_macro;
 use rustc_expand::expand::{AstFragment, Invocation, InvocationKind};
 use rustc_feature::is_builtin_attr_name;
@@ -176,10 +177,11 @@ impl<'a> ResolverExpand for Resolver<'a> {
         parent_scope.module.unexpanded_invocations.borrow_mut().remove(&expansion);
     }
 
-    fn register_builtin_macro(&mut self, ident: Ident, ext: SyntaxExtension) {
-        if self.builtin_macros.insert(ident.name, BuiltinMacroState::NotYetSeen(ext)).is_some() {
+    fn register_builtin_macro(&mut self, name: Symbol, ext: SyntaxExtensionKind) {
+        if self.builtin_macros.insert(name, BuiltinMacroState::NotYetSeen(ext)).is_some() {
             self.session
-                .span_err(ident.span, &format!("built-in macro `{}` was already defined", ident));
+                .diagnostic()
+                .bug(&format!("built-in macro `{}` was already registered", name));
         }
     }
 
@@ -1097,7 +1099,7 @@ impl<'a> Resolver<'a> {
                 // while still taking everything else from the source code.
                 // If we already loaded this builtin macro, give a better error message than 'no such builtin macro'.
                 match mem::replace(builtin_macro, BuiltinMacroState::AlreadySeen(item.span)) {
-                    BuiltinMacroState::NotYetSeen(ext) => result.kind = ext.kind,
+                    BuiltinMacroState::NotYetSeen(ext) => result.kind = ext,
                     BuiltinMacroState::AlreadySeen(span) => {
                         struct_span_err!(
                             self.session,