Auto merge of rust-lang#94333 - Dylan-DPC:rollup-7yxtywp, r=Dylan-DPC

Rollup of 9 pull requests

Successful merges:

 - rust-lang#91795 (resolve/metadata: Stop encoding macros as reexports)
 - rust-lang#93714 (better ObligationCause for normalization errors in `can_type_implement_copy`)
 - rust-lang#94175 (Improve `--check-cfg` implementation)
 - rust-lang#94212 (Stop manually SIMDing in `swap_nonoverlapping`)
 - rust-lang#94242 (properly handle fat pointers to uninhabitable types)
 - rust-lang#94308 (Normalize main return type during mono item collection & codegen)
 - rust-lang#94315 (update auto trait lint for `PhantomData`)
 - rust-lang#94316 (Improve string literal unescaping)
 - rust-lang#94327 (Avoid emitting full macro body into JSON errors)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_ast/src/lib.rs

@@ -16,6 +16,7 @@
 #![feature(min_specialization)]
 #![recursion_limit = "256"]
 #![feature(slice_internals)]
+#![feature(stmt_expr_attributes)]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_ast/src/util/literal.rs

@@ -56,25 +56,30 @@ impl LitKind {
                 // new symbol because the string in the LitKind is different to the
                 // string in the token.
                 let s = symbol.as_str();
-                let symbol =
-                    if s.contains(&['\\', '\r']) {
-                        let mut buf = String::with_capacity(s.len());
-                        let mut error = Ok(());
-                        unescape_literal(&s, Mode::Str, &mut |_, unescaped_char| {
-                            match unescaped_char {
-                                Ok(c) => buf.push(c),
-                                Err(err) => {
-                                    if err.is_fatal() {
-                                        error = Err(LitError::LexerError);
-                                    }
+                let symbol = if s.contains(&['\\', '\r']) {
+                    let mut buf = String::with_capacity(s.len());
+                    let mut error = Ok(());
+                    // Force-inlining here is aggressive but the closure is
+                    // called on every char in the string, so it can be
+                    // hot in programs with many long strings.
+                    unescape_literal(
+                        &s,
+                        Mode::Str,
+                        &mut #[inline(always)]
+                        |_, unescaped_char| match unescaped_char {
+                            Ok(c) => buf.push(c),
+                            Err(err) => {
+                                if err.is_fatal() {
+                                    error = Err(LitError::LexerError);
                                 }
                             }
-                        });
-                        error?;
-                        Symbol::intern(&buf)
-                    } else {
-                        symbol
-                    };
+                        },
+                    );
+                    error?;
+                    Symbol::intern(&buf)
+                } else {
+                    symbol
+                };
                 LitKind::Str(symbol, ast::StrStyle::Cooked)
             }
             token::StrRaw(n) => {

compiler/rustc_ast_lowering/src/item.rs

@@ -444,8 +444,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
             ),
             ItemKind::MacroDef(MacroDef { ref body, macro_rules }) => {
                 let body = P(self.lower_mac_args(body));
-
-                hir::ItemKind::Macro(ast::MacroDef { body, macro_rules })
+                let macro_kind = self.resolver.decl_macro_kind(self.resolver.local_def_id(id));
+                hir::ItemKind::Macro(ast::MacroDef { body, macro_rules }, macro_kind)
             }
             ItemKind::MacCall(..) => {
                 panic!("`TyMac` should have been expanded by now")

compiler/rustc_ast_lowering/src/lib.rs

@@ -61,7 +61,7 @@ use rustc_session::lint::LintBuffer;
 use rustc_session::parse::feature_err;
 use rustc_session::utils::{FlattenNonterminals, NtToTokenstream};
 use rustc_session::Session;
-use rustc_span::hygiene::ExpnId;
+use rustc_span::hygiene::{ExpnId, MacroKind};
 use rustc_span::source_map::{respan, DesugaringKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
@@ -210,6 +210,8 @@ pub trait ResolverAstLowering {
         expn_id: ExpnId,
         span: Span,
     ) -> LocalDefId;
+
+    fn decl_macro_kind(&self, def_id: LocalDefId) -> MacroKind;
 }
 
 /// Context of `impl Trait` in code, which determines whether it is allowed in an HIR subtree,

compiler/rustc_attr/src/builtin.rs

@@ -8,6 +8,7 @@ use rustc_errors::{struct_span_err, Applicability};
 use rustc_feature::{find_gated_cfg, is_builtin_attr_name, Features, GatedCfg};
 use rustc_macros::HashStable_Generic;
 use rustc_session::lint::builtin::UNEXPECTED_CFGS;
+use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_session::parse::{feature_err, ParseSess};
 use rustc_session::Session;
 use rustc_span::hygiene::Transparency;
@@ -461,29 +462,37 @@ pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Feat
                 true
             }
             MetaItemKind::NameValue(..) | MetaItemKind::Word => {
-                let name = cfg.ident().expect("multi-segment cfg predicate").name;
+                let ident = cfg.ident().expect("multi-segment cfg predicate");
+                let name = ident.name;
                 let value = cfg.value_str();
-                if sess.check_config.names_checked && !sess.check_config.names_valid.contains(&name)
-                {
-                    sess.buffer_lint(
-                        UNEXPECTED_CFGS,
-                        cfg.span,
-                        CRATE_NODE_ID,
-                        "unexpected `cfg` condition name",
-                    );
-                }
-                if let Some(val) = value {
-                    if sess.check_config.values_checked.contains(&name)
-                        && !sess.check_config.values_valid.contains(&(name, val))
-                    {
-                        sess.buffer_lint(
+                if let Some(names_valid) = &sess.check_config.names_valid {
+                    if !names_valid.contains(&name) {
+                        sess.buffer_lint_with_diagnostic(
                             UNEXPECTED_CFGS,
                             cfg.span,
                             CRATE_NODE_ID,
-                            "unexpected `cfg` condition value",
+                            "unexpected `cfg` condition name",
+                            BuiltinLintDiagnostics::UnexpectedCfg(ident.span, name, None),
                         );
                     }
                 }
+                if let Some(value) = value {
+                    if let Some(values) = &sess.check_config.values_valid.get(&name) {
+                        if !values.contains(&value) {
+                            sess.buffer_lint_with_diagnostic(
+                                UNEXPECTED_CFGS,
+                                cfg.span,
+                                CRATE_NODE_ID,
+                                "unexpected `cfg` condition value",
+                                BuiltinLintDiagnostics::UnexpectedCfg(
+                                    cfg.name_value_literal_span().unwrap(),
+                                    name,
+                                    Some(value),
+                                ),
+                            );
+                        }
+                    }
+                }
                 sess.config.contains(&(name, value))
             }
         }

compiler/rustc_codegen_cranelift/src/main_shim.rs

@@ -51,7 +51,10 @@ pub(crate) fn maybe_create_entry_wrapper(
         // late-bound regions, since late-bound
         // regions must appear in the argument
         // listing.
-        let main_ret_ty = tcx.erase_regions(main_ret_ty.no_bound_vars().unwrap());
+        let main_ret_ty = tcx.normalize_erasing_regions(
+            ty::ParamEnv::reveal_all(),
+            main_ret_ty.no_bound_vars().unwrap(),
+        );
 
         let cmain_sig = Signature {
             params: vec![

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -449,7 +449,10 @@ fn pointer_or_reference_metadata<'ll, 'tcx>(
             // This is a thin pointer. Create a regular pointer type and give it the correct name.
             debug_assert_eq!(
                 (thin_pointer_size, thin_pointer_align),
-                cx.size_and_align_of(ptr_type)
+                cx.size_and_align_of(ptr_type),
+                "ptr_type={}, pointee_type={}",
+                ptr_type,
+                pointee_type,
             );
 
             unsafe {

compiler/rustc_codegen_llvm/src/debuginfo/utils.rs

@@ -4,9 +4,9 @@ use super::namespace::item_namespace;
 use super::CrateDebugContext;
 
 use rustc_hir::def_id::DefId;
-use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::layout::{HasParamEnv, LayoutOf};
 use rustc_middle::ty::{self, DefIdTree, Ty};
-use rustc_target::abi::Variants;
+use tracing::trace;
 
 use crate::common::CodegenCx;
 use crate::llvm;
@@ -63,38 +63,37 @@ pub(crate) fn fat_pointer_kind<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
     pointee_ty: Ty<'tcx>,
 ) -> Option<FatPtrKind> {
-    let layout = cx.layout_of(pointee_ty);
+    let pointee_tail_ty = cx.tcx.struct_tail_erasing_lifetimes(pointee_ty, cx.param_env());
+    let layout = cx.layout_of(pointee_tail_ty);
+    trace!(
+        "fat_pointer_kind: {:?} has layout {:?} (is_unsized? {})",
+        pointee_tail_ty,
+        layout,
+        layout.is_unsized()
+    );
 
     if !layout.is_unsized() {
         return None;
     }
 
-    match *pointee_ty.kind() {
+    match *pointee_tail_ty.kind() {
         ty::Str | ty::Slice(_) => Some(FatPtrKind::Slice),
         ty::Dynamic(..) => Some(FatPtrKind::Dyn),
-        ty::Adt(..) | ty::Tuple(..) if matches!(layout.variants, Variants::Single { .. }) => {
-            let last_field_index = layout.fields.count() - 1;
-            debug_assert!(
-                (0..last_field_index)
-                    .all(|field_index| { !layout.field(cx, field_index).is_unsized() })
-            );
-
-            let unsized_field = layout.field(cx, last_field_index);
-            debug_assert!(unsized_field.is_unsized());
-            fat_pointer_kind(cx, unsized_field.ty)
-        }
         ty::Foreign(_) => {
             // Assert that pointers to foreign types really are thin:
             debug_assert_eq!(
-                cx.size_of(cx.tcx.mk_imm_ptr(pointee_ty)),
+                cx.size_of(cx.tcx.mk_imm_ptr(pointee_tail_ty)),
                 cx.size_of(cx.tcx.mk_imm_ptr(cx.tcx.types.u8))
             );
             None
         }
         _ => {
             // For all other pointee types we should already have returned None
             // at the beginning of the function.
-            panic!("fat_pointer_kind() - Encountered unexpected `pointee_ty`: {:?}", pointee_ty)
+            panic!(
+                "fat_pointer_kind() - Encountered unexpected `pointee_tail_ty`: {:?}",
+                pointee_tail_ty
+            )
         }
     }
 }

compiler/rustc_codegen_ssa/src/base.rs

@@ -407,7 +407,10 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         // late-bound regions, since late-bound
         // regions must appear in the argument
         // listing.
-        let main_ret_ty = cx.tcx().erase_regions(main_ret_ty.no_bound_vars().unwrap());
+        let main_ret_ty = cx.tcx().normalize_erasing_regions(
+            ty::ParamEnv::reveal_all(),
+            main_ret_ty.no_bound_vars().unwrap(),
+        );
 
         let Some(llfn) = cx.declare_c_main(llfty) else {
             // FIXME: We should be smart and show a better diagnostic here.

compiler/rustc_errors/src/json.rs

@@ -454,8 +454,14 @@ impl DiagnosticSpan {
         let end = je.sm.lookup_char_pos(span.hi());
         let backtrace_step = backtrace.next().map(|bt| {
             let call_site = Self::from_span_full(bt.call_site, false, None, None, backtrace, je);
-            let def_site_span =
-                Self::from_span_full(bt.def_site, false, None, None, [].into_iter(), je);
+            let def_site_span = Self::from_span_full(
+                je.sm.guess_head_span(bt.def_site),
+                false,
+                None,
+                None,
+                [].into_iter(),
+                je,
+            );
             Box::new(DiagnosticSpanMacroExpansion {
                 span: call_site,
                 macro_decl_name: bt.kind.descr(),

compiler/rustc_hir/src/hir.rs

@@ -15,6 +15,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sorted_map::SortedMap;
 use rustc_index::vec::IndexVec;
 use rustc_macros::HashStable_Generic;
+use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{def_id::LocalDefId, BytePos, MultiSpan, Span, DUMMY_SP};
@@ -2803,7 +2804,7 @@ pub enum ItemKind<'hir> {
     /// A function declaration.
     Fn(FnSig<'hir>, Generics<'hir>, BodyId),
     /// A MBE macro definition (`macro_rules!` or `macro`).
-    Macro(ast::MacroDef),
+    Macro(ast::MacroDef, MacroKind),
     /// A module.
     Mod(Mod<'hir>),
     /// An external module, e.g. `extern { .. }`.

compiler/rustc_hir/src/intravisit.rs

@@ -575,7 +575,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
             item.span,
             item.hir_id(),
         ),
-        ItemKind::Macro(_) => {
+        ItemKind::Macro(..) => {
             visitor.visit_id(item.hir_id());
         }
         ItemKind::Mod(ref module) => {

compiler/rustc_hir_pretty/src/lib.rs

@@ -570,7 +570,7 @@ impl<'a> State<'a> {
                 self.end(); // need to close a box
                 self.ann.nested(self, Nested::Body(body));
             }
-            hir::ItemKind::Macro(ref macro_def) => {
+            hir::ItemKind::Macro(ref macro_def, _) => {
                 self.print_mac_def(macro_def, &item.ident, item.span, |state| {
                     state.print_visibility(&item.vis)
                 });

compiler/rustc_interface/src/interface.rs

@@ -169,11 +169,12 @@ pub fn parse_check_cfg(specs: Vec<String>) -> CheckCfg {
                     Ok(meta_item) if parser.token == token::Eof => {
                         if let Some(args) = meta_item.meta_item_list() {
                             if meta_item.has_name(sym::names) {
-                                cfg.names_checked = true;
+                                let names_valid =
+                                    cfg.names_valid.get_or_insert_with(|| FxHashSet::default());
                                 for arg in args {
                                     if arg.is_word() && arg.ident().is_some() {
                                         let ident = arg.ident().expect("multi-segment cfg key");
-                                        cfg.names_valid.insert(ident.name.to_string());
+                                        names_valid.insert(ident.name.to_string());
                                     } else {
                                         error!("`names()` arguments must be simple identifers");
                                     }
@@ -183,13 +184,16 @@ pub fn parse_check_cfg(specs: Vec<String>) -> CheckCfg {
                                 if let Some((name, values)) = args.split_first() {
                                     if name.is_word() && name.ident().is_some() {
                                         let ident = name.ident().expect("multi-segment cfg key");
-                                        cfg.values_checked.insert(ident.to_string());
+                                        let ident_values = cfg
+                                            .values_valid
+                                            .entry(ident.name.to_string())
+                                            .or_insert_with(|| FxHashSet::default());
+
                                         for val in values {
                                             if let Some(LitKind::Str(s, _)) =
                                                 val.literal().map(|lit| &lit.kind)
                                             {
-                                                cfg.values_valid
-                                                    .insert((ident.to_string(), s.to_string()));
+                                                ident_values.insert(s.to_string());
                                             } else {
                                                 error!(
                                                     "`values()` arguments must be string literals"
@@ -219,7 +223,9 @@ pub fn parse_check_cfg(specs: Vec<String>) -> CheckCfg {
             );
         }
 
-        cfg.names_valid.extend(cfg.values_checked.iter().cloned());
+        if let Some(names_valid) = &mut cfg.names_valid {
+            names_valid.extend(cfg.values_valid.keys().cloned());
+        }
         cfg
     })
 }