Auto merge of #155311 - cyrgani:expand-clean, r=<try>

various small `rustc_expand` cleanups

Author: bors

compiler/rustc_expand/src/base.rs

@@ -409,17 +409,10 @@ pub trait GlobDelegationExpander {
     fn expand(&self, ecx: &mut ExtCtxt<'_>) -> ExpandResult<Vec<(Ident, Option<Ident>)>, ()>;
 }
 
-// Use a macro because forwarding to a simple function has type system issues
-macro_rules! make_stmts_default {
-    ($me:expr) => {
-        $me.make_expr().map(|e| {
-            smallvec![ast::Stmt {
-                id: ast::DUMMY_NODE_ID,
-                span: e.span,
-                kind: ast::StmtKind::Expr(e),
-            }]
-        })
-    };
+fn make_stmts_default(expr: Option<Box<ast::Expr>>) -> Option<SmallVec<[ast::Stmt; 1]>> {
+    expr.map(|e| {
+        smallvec![ast::Stmt { id: ast::DUMMY_NODE_ID, span: e.span, kind: ast::StmtKind::Expr(e) }]
+    })
 }
 
 /// The result of a macro expansion. The return values of the various
@@ -465,7 +458,7 @@ pub trait MacResult {
     /// By default this attempts to create an expression statement,
     /// returning None if that fails.
     fn make_stmts(self: Box<Self>) -> Option<SmallVec<[ast::Stmt; 1]>> {
-        make_stmts_default!(self)
+        make_stmts_default(self.make_expr())
     }
 
     fn make_ty(self: Box<Self>) -> Option<Box<ast::Ty>> {
@@ -571,9 +564,10 @@ impl MacResult for MacEager {
     }
 
     fn make_stmts(self: Box<Self>) -> Option<SmallVec<[ast::Stmt; 1]>> {
-        match self.stmts.as_ref().map_or(0, |s| s.len()) {
-            0 => make_stmts_default!(self),
-            _ => self.stmts,
+        if self.stmts.as_ref().is_none_or(|s| s.is_empty()) {
+            make_stmts_default(self.make_expr())
+        } else {
+            self.stmts
         }
     }
 
@@ -898,7 +892,7 @@ impl SyntaxExtension {
     fn get_collapse_debuginfo(sess: &Session, attrs: &[hir::Attribute], ext: bool) -> bool {
         let flag = sess.opts.cg.collapse_macro_debuginfo;
         let attr = if let Some(info) = find_attr!(attrs, CollapseDebugInfo(info) => info) {
-            info.clone()
+            *info
         } else if find_attr!(attrs, RustcBuiltinMacro { .. }) {
             CollapseMacroDebuginfo::Yes
         } else {

compiler/rustc_expand/src/config.rs

@@ -106,33 +106,24 @@ 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| feature_ident.name == f.name).is_some() {
-                // When the ICE comes from 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(feature_ident.name)
-                    && !STDLIB_STABLE_CRATES.contains(&crate_name)
-                {
-                    sess.using_internal_features.store(true, std::sync::atomic::Ordering::Relaxed);
-                }
-
                 features.set_enabled_lang_feature(EnabledLangFeature {
                     gate_name: feature_ident.name,
                     attr_sp: feature_ident.span,
                     stable_since: None,
                 });
-                continue;
+            } else {
+                // Otherwise, the feature is unknown. Enable it as a lib feature.
+                // It will be checked later whether the feature really exists.
+                features.set_enabled_lib_feature(EnabledLibFeature {
+                    gate_name: feature_ident.name,
+                    attr_sp: feature_ident.span,
+                });
             }
 
-            // Otherwise, the feature is unknown. Enable it as a lib feature.
-            // It will be checked later whether the feature really exists.
-            features.set_enabled_lib_feature(EnabledLibFeature {
-                gate_name: feature_ident.name,
-                attr_sp: feature_ident.span,
-            });
-
-            // Similar to above, detect internal lib features to suppress
-            // the ICE message that asks for a report.
+            // When the ICE comes from 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(feature_ident.name) && !STDLIB_STABLE_CRATES.contains(&crate_name)
             {
                 sess.using_internal_features.store(true, std::sync::atomic::Ordering::Relaxed);
@@ -285,7 +276,7 @@ impl<'a> StripUnconfigured<'a> {
 
         let Some((cfg_predicate, expanded_attrs)) = rustc_attr_parsing::parse_cfg_attr(
             cfg_attr,
-            &self.sess,
+            self.sess,
             self.features,
             self.lint_node_id,
         ) else {
@@ -422,7 +413,7 @@ impl<'a> StripUnconfigured<'a> {
             && !attr.span.allows_unstable(sym::stmt_expr_attributes)
         {
             let mut err = feature_err(
-                &self.sess,
+                self.sess,
                 sym::stmt_expr_attributes,
                 attr.span,
                 msg!("attributes on expressions are experimental"),

compiler/rustc_expand/src/expand.rs

@@ -1050,7 +1050,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             return;
         }
         feature_err(
-            &self.cx.sess,
+            self.cx.sess,
             sym::proc_macro_hygiene,
             span,
             format!("custom attributes cannot be applied to {kind}"),
@@ -1085,7 +1085,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         }
 
         if !self.cx.ecfg.features.proc_macro_hygiene() {
-            annotatable.visit_with(&mut GateProcMacroInput { sess: &self.cx.sess });
+            annotatable.visit_with(&mut GateProcMacroInput { sess: self.cx.sess });
         }
     }
 
@@ -1474,15 +1474,15 @@ impl InvocationCollectorNode for Box<ast::Item> {
                 }
             }
             let mut idents = Vec::new();
-            collect_use_tree_leaves(&ut, &mut idents);
+            collect_use_tree_leaves(ut, &mut idents);
             idents
         } else {
             self.kind.ident().into_iter().collect()
         }
     }
 
     fn as_target(&self) -> Target {
-        Target::from_ast_item(&*self)
+        Target::from_ast_item(self)
     }
 }
 

compiler/rustc_expand/src/mbe/diagnostics.rs

@@ -288,52 +288,47 @@ pub(super) fn emit_frag_parse_err(
         _ => annotate_err_with_kind(&mut e, kind, site_span),
     };
 
-    let mut bindings_rules = vec![];
-    for rule in bindings {
-        let MacroRule::Func { lhs, .. } = rule else { continue };
-        for param in lhs {
-            let MatcherLoc::MetaVarDecl { bind, .. } = param else { continue };
-            bindings_rules.push(*bind);
-        }
-    }
-
-    let mut matched_rule_bindings_rules = vec![];
-    for param in matched_rule_bindings {
-        let MatcherLoc::MetaVarDecl { bind, .. } = param else { continue };
-        matched_rule_bindings_rules.push(*bind);
-    }
-
-    let matched_rule_bindings_names: Vec<_> =
-        matched_rule_bindings_rules.iter().map(|bind| bind.name).collect();
-    let bindings_name: Vec<_> = bindings_rules.iter().map(|bind| bind.name).collect();
     if parser.token.kind == token::Dollar {
         parser.bump();
         if let token::Ident(name, _) = parser.token.kind {
+            let mut bindings_names = vec![];
+            for rule in bindings {
+                let MacroRule::Func { lhs, .. } = rule else { continue };
+                for param in lhs {
+                    let MatcherLoc::MetaVarDecl { bind, .. } = param else { continue };
+                    bindings_names.push(bind.name);
+                }
+            }
+
+            let mut matched_rule_bindings_names = vec![];
+            for param in matched_rule_bindings {
+                let MatcherLoc::MetaVarDecl { bind, .. } = param else { continue };
+                matched_rule_bindings_names.push(bind.name);
+            }
+
             if let Some(matched_name) = rustc_span::edit_distance::find_best_match_for_name(
                 &matched_rule_bindings_names[..],
                 name,
                 None,
             ) {
                 e.span_suggestion_verbose(
                     parser.token.span,
-                    "there is a macro metavariable with similar name",
-                    format!("{matched_name}"),
+                    "there is a macro metavariable with a similar name",
+                    matched_name,
                     Applicability::MaybeIncorrect,
                 );
-            } else if bindings_name.contains(&name) {
+            } else if bindings_names.contains(&name) {
                 e.span_label(
                     parser.token.span,
-                    format!(
-                        "there is an macro metavariable with this name in another macro matcher"
-                    ),
+                    "there is an macro metavariable with this name in another macro matcher",
                 );
             } else if let Some(matched_name) =
-                rustc_span::edit_distance::find_best_match_for_name(&bindings_name[..], name, None)
+                rustc_span::edit_distance::find_best_match_for_name(&bindings_names[..], name, None)
             {
                 e.span_suggestion_verbose(
                     parser.token.span,
                     "there is a macro metavariable with a similar name in another macro matcher",
-                    format!("{matched_name}"),
+                    matched_name,
                     Applicability::MaybeIncorrect,
                 );
             } else {
@@ -343,7 +338,7 @@ pub(super) fn emit_frag_parse_err(
                     .collect::<Vec<_>>()
                     .join(", ");
 
-                e.span_label(parser.token.span, format!("macro metavariable not found"));
+                e.span_label(parser.token.span, "macro metavariable not found");
                 if !matched_rule_bindings_names.is_empty() {
                     e.note(format!("available metavariable names are: {msg}"));
                 }

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -199,8 +199,8 @@ pub(super) fn compute_locs(matcher: &[TokenTree]) -> Vec<MatcherLoc> {
                     let idx_seq = idx_first - 1;
                     inner(&seq.tts, locs, next_metavar, seq_depth + 1);
 
-                    if let Some(separator) = &seq.separator {
-                        locs.push(MatcherLoc::SequenceSep { separator: separator.clone() });
+                    if let Some(separator) = seq.separator {
+                        locs.push(MatcherLoc::SequenceSep { separator });
                         locs.push(MatcherLoc::SequenceKleeneOpAfterSep { idx_first });
                     } else {
                         locs.push(MatcherLoc::SequenceKleeneOpNoSep { op, idx_first });

compiler/rustc_expand/src/mbe/quoted.rs

@@ -214,7 +214,7 @@ fn parse_tree<'a>(
             // during parsing.
             let mut next = outer_iter.next();
             let mut iter_storage;
-            let mut iter: &mut TokenStreamIter<'_> = match next {
+            let iter: &mut TokenStreamIter<'_> = match next {
                 Some(tokenstream::TokenTree::Delimited(.., delim, tts)) if delim.skip() => {
                     iter_storage = tts.iter();
                     next = iter_storage.next();
@@ -284,7 +284,7 @@ fn parse_tree<'a>(
                     let sequence = parse(tts, part, sess, node_id, features, edition);
                     // Get the Kleene operator and optional separator
                     let (separator, kleene) =
-                        parse_sep_and_kleene_op(&mut iter, delim_span.entire(), sess);
+                        parse_sep_and_kleene_op(iter, delim_span.entire(), sess);
                     // Count the number of captured "names" (i.e., named metavars)
                     let num_captures =
                         if part.is_pattern() { count_metavar_decls(&sequence) } else { 0 };

compiler/rustc_expand/src/mbe/transcribe.rs

@@ -396,7 +396,7 @@ fn transcribe_sequence<'tx, 'itp>(
                 // The first time we encounter the sequence we push it to the stack. It
                 // then gets reused (see the beginning of the loop) until we are done
                 // repeating.
-                tscx.stack.push(Frame::new_sequence(seq_rep, seq.separator.clone(), seq.kleene.op));
+                tscx.stack.push(Frame::new_sequence(seq_rep, seq.separator, seq.kleene.op));
             }
         }
     }
@@ -629,7 +629,7 @@ fn metavar_expr_concat<'tx>(
 ) -> PResult<'tx, TokenTree> {
     let dcx = tscx.psess.dcx();
     let mut concatenated = String::new();
-    for element in elements.into_iter() {
+    for element in elements {
         let symbol = match element {
             MetaVarExprConcatElem::Ident(elem) => elem.name,
             MetaVarExprConcatElem::Literal(elem) => *elem,
@@ -747,7 +747,7 @@ fn maybe_use_metavar_location(
         TokenTree::Token(Token { kind, span }, spacing) => {
             let span = metavar_span.with_ctxt(span.ctxt());
             with_metavar_spans(|mspans| mspans.insert(span, metavar_span));
-            TokenTree::Token(Token { kind: kind.clone(), span }, *spacing)
+            TokenTree::Token(Token { kind: *kind, span }, *spacing)
         }
         TokenTree::Delimited(dspan, dspacing, delimiter, tts) => {
             let open = metavar_span.with_ctxt(dspan.open.ctxt());

compiler/rustc_expand/src/module.rs

@@ -77,7 +77,7 @@ pub(crate) fn parse_external_mod(
             Some(span),
         ));
         let (inner_attrs, items, inner_span) =
-            parser.parse_mod(exp!(Eof)).map_err(|err| ModError::ParserError(err))?;
+            parser.parse_mod(exp!(Eof)).map_err(ModError::ParserError)?;
         attrs.extend(inner_attrs);
         (items, inner_span, mp.file_path)
     };