Rollup merge of rust-lang#124607 - nnethercote:rustc_expand-cleanups, r=compiler-errors

`rustc_expand` cleanups

Some cleanups I made while looking through this code. Nothing that requires any real domain-specific knowledge about this crate.

r? ```@michaelwoerister```

Author: fmease

compiler/rustc_expand/src/base.rs

@@ -21,7 +21,7 @@ use rustc_session::config::CollapseMacroDebuginfo;
 use rustc_session::{parse::ParseSess, Limit, Session};
 use rustc_span::def_id::{CrateNum, DefId, LocalDefId};
 use rustc_span::edition::Edition;
-use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId};
+use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId, MacroKind};
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{FileName, Span, DUMMY_SP};
@@ -32,8 +32,6 @@ use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use thin_vec::ThinVec;
 
-pub(crate) use rustc_span::hygiene::MacroKind;
-
 // When adding new variants, make sure to
 // adjust the `visit_*` / `flat_map_*` calls in `InvocationCollector`
 // to use `assign_id!`
@@ -573,35 +571,6 @@ impl DummyResult {
             tokens: None,
         })
     }
-
-    /// A plain dummy pattern.
-    pub fn raw_pat(sp: Span) -> ast::Pat {
-        ast::Pat { id: ast::DUMMY_NODE_ID, kind: PatKind::Wild, span: sp, tokens: None }
-    }
-
-    /// A plain dummy type.
-    pub fn raw_ty(sp: Span) -> P<ast::Ty> {
-        // FIXME(nnethercote): you might expect `ast::TyKind::Dummy` to be used here, but some
-        // values produced here end up being lowered to HIR, which `ast::TyKind::Dummy` does not
-        // support, so we use an empty tuple instead.
-        P(ast::Ty {
-            id: ast::DUMMY_NODE_ID,
-            kind: ast::TyKind::Tup(ThinVec::new()),
-            span: sp,
-            tokens: None,
-        })
-    }
-
-    /// A plain dummy crate.
-    pub fn raw_crate() -> ast::Crate {
-        ast::Crate {
-            attrs: Default::default(),
-            items: Default::default(),
-            spans: Default::default(),
-            id: ast::DUMMY_NODE_ID,
-            is_placeholder: Default::default(),
-        }
-    }
 }
 
 impl MacResult for DummyResult {
@@ -610,7 +579,12 @@ impl MacResult for DummyResult {
     }
 
     fn make_pat(self: Box<DummyResult>) -> Option<P<ast::Pat>> {
-        Some(P(DummyResult::raw_pat(self.span)))
+        Some(P(ast::Pat {
+            id: ast::DUMMY_NODE_ID,
+            kind: PatKind::Wild,
+            span: self.span,
+            tokens: None,
+        }))
     }
 
     fn make_items(self: Box<DummyResult>) -> Option<SmallVec<[P<ast::Item>; 1]>> {
@@ -638,7 +612,15 @@ impl MacResult for DummyResult {
     }
 
     fn make_ty(self: Box<DummyResult>) -> Option<P<ast::Ty>> {
-        Some(DummyResult::raw_ty(self.span))
+        // FIXME(nnethercote): you might expect `ast::TyKind::Dummy` to be used here, but some
+        // values produced here end up being lowered to HIR, which `ast::TyKind::Dummy` does not
+        // support, so we use an empty tuple instead.
+        Some(P(ast::Ty {
+            id: ast::DUMMY_NODE_ID,
+            kind: ast::TyKind::Tup(ThinVec::new()),
+            span: self.span,
+            tokens: None,
+        }))
     }
 
     fn make_arms(self: Box<DummyResult>) -> Option<SmallVec<[ast::Arm; 1]>> {
@@ -670,7 +652,13 @@ impl MacResult for DummyResult {
     }
 
     fn make_crate(self: Box<DummyResult>) -> Option<ast::Crate> {
-        Some(DummyResult::raw_crate())
+        Some(ast::Crate {
+            attrs: Default::default(),
+            items: Default::default(),
+            spans: Default::default(),
+            id: ast::DUMMY_NODE_ID,
+            is_placeholder: Default::default(),
+        })
     }
 }
 

compiler/rustc_expand/src/build.rs

@@ -175,20 +175,6 @@ impl<'a> ExtCtxt<'a> {
         ast::Stmt { id: ast::DUMMY_NODE_ID, span: expr.span, kind: ast::StmtKind::Expr(expr) }
     }
 
-    pub fn stmt_let_pat(&self, sp: Span, pat: P<ast::Pat>, ex: P<ast::Expr>) -> ast::Stmt {
-        let local = P(ast::Local {
-            pat,
-            ty: None,
-            id: ast::DUMMY_NODE_ID,
-            kind: LocalKind::Init(ex),
-            span: sp,
-            colon_sp: None,
-            attrs: AttrVec::new(),
-            tokens: None,
-        });
-        self.stmt_local(local, sp)
-    }
-
     pub fn stmt_let(&self, sp: Span, mutbl: bool, ident: Ident, ex: P<ast::Expr>) -> ast::Stmt {
         self.stmt_let_ty(sp, mutbl, ident, None, ex)
     }
@@ -278,10 +264,6 @@ impl<'a> ExtCtxt<'a> {
         self.expr_ident(span, Ident::with_dummy_span(kw::SelfLower))
     }
 
-    pub fn expr_field(&self, span: Span, expr: P<Expr>, field: Ident) -> P<ast::Expr> {
-        self.expr(span, ast::ExprKind::Field(expr, field))
-    }
-
     pub fn expr_macro_call(&self, span: Span, call: P<ast::MacCall>) -> P<ast::Expr> {
         self.expr(span, ast::ExprKind::MacCall(call))
     }
@@ -394,11 +376,6 @@ impl<'a> ExtCtxt<'a> {
         self.expr(span, ast::ExprKind::Lit(lit))
     }
 
-    pub fn expr_char(&self, span: Span, ch: char) -> P<ast::Expr> {
-        let lit = token::Lit::new(token::Char, literal::escape_char_symbol(ch), None);
-        self.expr(span, ast::ExprKind::Lit(lit))
-    }
-
     pub fn expr_byte_str(&self, span: Span, bytes: Vec<u8>) -> P<ast::Expr> {
         let lit = token::Lit::new(token::ByteStr, literal::escape_byte_str_symbol(&bytes), None);
         self.expr(span, ast::ExprKind::Lit(lit))
@@ -414,10 +391,6 @@ impl<'a> ExtCtxt<'a> {
         self.expr_addr_of(sp, self.expr_array(sp, exprs))
     }
 
-    pub fn expr_cast(&self, sp: Span, expr: P<ast::Expr>, ty: P<ast::Ty>) -> P<ast::Expr> {
-        self.expr(sp, ast::ExprKind::Cast(expr, ty))
-    }
-
     pub fn expr_some(&self, sp: Span, expr: P<ast::Expr>) -> P<ast::Expr> {
         let some = self.std_path(&[sym::option, sym::Option, sym::Some]);
         self.expr_call_global(sp, some, thin_vec![expr])

compiler/rustc_expand/src/config.rs

@@ -99,10 +99,11 @@ pub fn features(sess: &Session, krate_attrs: &[Attribute], crate_name: Symbol) -
             // If the declared feature is unstable, record it.
             if let Some(f) = UNSTABLE_FEATURES.iter().find(|f| name == f.feature.name) {
                 (f.set_enabled)(&mut features);
-                // 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.
+                // 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)
                 {

compiler/rustc_expand/src/expand.rs

@@ -4,7 +4,6 @@ use crate::errors::{
     IncompleteParse, RecursionLimitReached, RemoveExprNotSupported, RemoveNodeNotSupported,
     UnsupportedKeyValue, WrongFragmentKind,
 };
-use crate::hygiene::SyntaxContext;
 use crate::mbe::diagnostics::annotate_err_with_kind;
 use crate::module::{mod_dir_path, parse_external_mod, DirOwnership, ParsedExternalMod};
 use crate::placeholders::{placeholder, PlaceholderExpander};
@@ -32,6 +31,7 @@ use rustc_session::lint::builtin::{UNUSED_ATTRIBUTES, UNUSED_DOC_COMMENTS};
 use rustc_session::lint::BuiltinLintDiag;
 use rustc_session::parse::feature_err;
 use rustc_session::{Limit, Session};
+use rustc_span::hygiene::SyntaxContext;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::{ErrorGuaranteed, FileName, LocalExpnId, Span};
 
@@ -87,7 +87,7 @@ macro_rules! ast_fragments {
         }
 
         impl AstFragment {
-            pub fn add_placeholders(&mut self, placeholders: &[NodeId]) {
+            fn add_placeholders(&mut self, placeholders: &[NodeId]) {
                 if placeholders.is_empty() {
                     return;
                 }
@@ -100,14 +100,14 @@ macro_rules! ast_fragments {
                 }
             }
 
-            pub fn make_opt_expr(self) -> Option<P<ast::Expr>> {
+            pub(crate) fn make_opt_expr(self) -> Option<P<ast::Expr>> {
                 match self {
                     AstFragment::OptExpr(expr) => expr,
                     _ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
                 }
             }
 
-            pub fn make_method_receiver_expr(self) -> P<ast::Expr> {
+            pub(crate) fn make_method_receiver_expr(self) -> P<ast::Expr> {
                 match self {
                     AstFragment::MethodReceiverExpr(expr) => expr,
                     _ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
@@ -125,7 +125,7 @@ macro_rules! ast_fragments {
                 T::fragment_to_output(self)
             }
 
-            pub fn mut_visit_with<F: MutVisitor>(&mut self, vis: &mut F) {
+            pub(crate) fn mut_visit_with<F: MutVisitor>(&mut self, vis: &mut F) {
                 match self {
                     AstFragment::OptExpr(opt_expr) => {
                         visit_clobber(opt_expr, |opt_expr| {
@@ -372,6 +372,14 @@ impl Invocation {
             InvocationKind::Derive { path, .. } => path.span,
         }
     }
+
+    fn span_mut(&mut self) -> &mut Span {
+        match &mut self.kind {
+            InvocationKind::Bang { span, .. } => span,
+            InvocationKind::Attr { attr, .. } => &mut attr.span,
+            InvocationKind::Derive { path, .. } => &mut path.span,
+        }
+    }
 }
 
 pub struct MacroExpander<'a, 'b> {
@@ -432,7 +440,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                     break;
                 }
                 invocations = mem::take(&mut undetermined_invocations);
-                force = !mem::replace(&mut progress, false);
+                force = !progress;
+                progress = false;
                 if force && self.monotonic {
                     self.cx.dcx().span_delayed_bug(
                         invocations.last().unwrap().0.span(),
@@ -471,7 +480,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             self.cx.force_mode = force;
 
             let fragment_kind = invoc.fragment_kind;
-            let (expanded_fragment, new_invocations) = match self.expand_invoc(invoc, &ext.kind) {
+            match self.expand_invoc(invoc, &ext.kind) {
                 ExpandResult::Ready(fragment) => {
                     let mut derive_invocations = Vec::new();
                     let derive_placeholders = self
@@ -503,12 +512,19 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                         })
                         .unwrap_or_default();
 
-                    let (fragment, collected_invocations) =
+                    let (expanded_fragment, collected_invocations) =
                         self.collect_invocations(fragment, &derive_placeholders);
-                    // We choose to expand any derive invocations associated with this macro invocation
-                    // *before* any macro invocations collected from the output fragment
+                    // We choose to expand any derive invocations associated with this macro
+                    // invocation *before* any macro invocations collected from the output
+                    // fragment.
                     derive_invocations.extend(collected_invocations);
-                    (fragment, derive_invocations)
+
+                    progress = true;
+                    if expanded_fragments.len() < depth {
+                        expanded_fragments.push(Vec::new());
+                    }
+                    expanded_fragments[depth - 1].push((expn_id, expanded_fragment));
+                    invocations.extend(derive_invocations.into_iter().rev());
                 }
                 ExpandResult::Retry(invoc) => {
                     if force {
@@ -519,17 +535,9 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                     } else {
                         // Cannot expand, will retry this invocation later.
                         undetermined_invocations.push((invoc, Some(ext)));
-                        continue;
                     }
                 }
-            };
-
-            progress = true;
-            if expanded_fragments.len() < depth {
-                expanded_fragments.push(Vec::new());
             }
-            expanded_fragments[depth - 1].push((expn_id, expanded_fragment));
-            invocations.extend(new_invocations.into_iter().rev());
         }
 
         self.cx.current_expansion = orig_expansion_data;
@@ -590,11 +598,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 for (invoc, _) in invocations.iter_mut() {
                     let expn_id = invoc.expansion_data.id;
                     let parent_def = self.cx.resolver.invocation_parent(expn_id);
-                    let span = match &mut invoc.kind {
-                        InvocationKind::Bang { span, .. } => span,
-                        InvocationKind::Attr { attr, .. } => &mut attr.span,
-                        InvocationKind::Derive { path, .. } => &mut path.span,
-                    };
+                    let span = invoc.span_mut();
                     *span = span.with_parent(Some(parent_def));
                 }
             }
@@ -957,7 +961,7 @@ pub fn parse_ast_fragment<'a>(
     })
 }
 
-pub fn ensure_complete_parse<'a>(
+pub(crate) fn ensure_complete_parse<'a>(
     parser: &Parser<'a>,
     macro_path: &ast::Path,
     kind_name: &str,

compiler/rustc_expand/src/lib.rs

@@ -1,43 +1,39 @@
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::diagnostic_outside_of_impl)]
 #![doc(rust_logo)]
-#![feature(rustdoc_internals)]
 #![feature(array_windows)]
 #![feature(associated_type_defaults)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
-#![feature(lint_reasons)]
 #![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_internals)]
-#![feature(proc_macro_span)]
+#![feature(rustdoc_internals)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
-#![allow(rustc::diagnostic_outside_of_impl)]
-#![allow(internal_features)]
+// tidy-alphabetical-end
 
 extern crate proc_macro as pm;
 
+mod build;
+mod errors;
+// FIXME(Nilstrieb) Translate macro_rules diagnostics
+#[allow(rustc::untranslatable_diagnostic)]
+mod mbe;
 mod placeholders;
 mod proc_macro_server;
 
 pub use mbe::macro_rules::compile_declarative_macro;
-pub(crate) use rustc_span::hygiene;
 pub mod base;
-pub mod build;
-#[macro_use]
 pub mod config;
-pub mod errors;
 pub mod expand;
 pub mod module;
-
 // FIXME(Nilstrieb) Translate proc_macro diagnostics
 #[allow(rustc::untranslatable_diagnostic)]
 pub mod proc_macro;
 
-// FIXME(Nilstrieb) Translate macro_rules diagnostics
-#[allow(rustc::untranslatable_diagnostic)]
-pub(crate) mod mbe;
-
 // HACK(Centril, #64197): These shouldn't really be here.
 // Rather, they should be with their respective modules which are defined in other crates.
 // However, since for now constructing a `ParseSess` sorta requires `config` from this crate,

compiler/rustc_expand/src/mbe.rs

@@ -4,12 +4,13 @@
 //! official terminology: "declarative macros".
 
 pub(crate) mod diagnostics;
-pub(crate) mod macro_check;
-pub(crate) mod macro_parser;
 pub(crate) mod macro_rules;
-pub(crate) mod metavar_expr;
-pub(crate) mod quoted;
-pub(crate) mod transcribe;
+
+mod macro_check;
+mod macro_parser;
+mod metavar_expr;
+mod quoted;
+mod transcribe;
 
 use metavar_expr::MetaVarExpr;
 use rustc_ast::token::{Delimiter, NonterminalKind, Token, TokenKind};