Auto merge of rust-lang#137402 - matthiaskrgr:rollup-hqdeztj, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#136458 (Do not deduplicate list of associated types provided by dyn principal)
 - rust-lang#136474 ([`compiletest`-related cleanups 3/7] Make the distinction between sources root vs test suite sources root in compiletest less confusing)
 - rust-lang#136592 (Make sure we don't overrun the stack in canonicalizer)
 - rust-lang#136787 (Remove `lifetime_capture_rules_2024` feature)
 - rust-lang#137180 (Give `global_asm` a fake body to store typeck results, represent `sym fn` as a hir expr to fix `sym fn` operands with lifetimes)
 - rust-lang#137257 (Ignore fake borrows for packed field check)
 - rust-lang#137348 (More sophisticated span trimming for suggestions)
 - rust-lang#137399 (fix ICE in layout computation with unnormalizable const)

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

Author: bors

compiler/rustc_ast_lowering/src/asm.rs

@@ -1,13 +1,12 @@
 use std::collections::hash_map::Entry;
 use std::fmt::Write;
 
-use rustc_ast::ptr::P;
 use rustc_ast::*;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_session::parse::feature_err;
-use rustc_span::{Span, kw, sym};
+use rustc_span::{Span, sym};
 use rustc_target::asm;
 
 use super::LoweringContext;
@@ -230,20 +229,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                                 tokens: None,
                             };
 
-                            // Wrap the expression in an AnonConst.
-                            let parent_def_id = self.current_hir_id_owner.def_id;
-                            let node_id = self.next_node_id();
-                            self.create_def(
-                                parent_def_id,
-                                node_id,
-                                kw::Empty,
-                                DefKind::AnonConst,
-                                *op_sp,
-                            );
-                            let anon_const = AnonConst { id: node_id, value: P(expr) };
-                            hir::InlineAsmOperand::SymFn {
-                                anon_const: self.lower_anon_const_to_anon_const(&anon_const),
-                            }
+                            hir::InlineAsmOperand::SymFn { expr: self.lower_expr(&expr) }
                         }
                     }
                     InlineAsmOperand::Label { block } => {

compiler/rustc_ast_lowering/src/item.rs

@@ -251,7 +251,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     .arena
                     .alloc_from_iter(fm.items.iter().map(|x| self.lower_foreign_item_ref(x))),
             },
-            ItemKind::GlobalAsm(asm) => hir::ItemKind::GlobalAsm(self.lower_inline_asm(span, asm)),
+            ItemKind::GlobalAsm(asm) => {
+                let asm = self.lower_inline_asm(span, asm);
+                let fake_body =
+                    self.lower_body(|this| (&[], this.expr(span, hir::ExprKind::InlineAsm(asm))));
+                hir::ItemKind::GlobalAsm { asm, fake_body }
+            }
             ItemKind::TyAlias(box TyAlias { generics, where_clauses, ty, .. }) => {
                 // We lower
                 //

compiler/rustc_borrowck/src/universal_regions.rs

@@ -126,6 +126,11 @@ pub(crate) enum DefiningTy<'tcx> {
     /// The MIR represents an inline const. The signature has no inputs and a
     /// single return value found via `InlineConstArgs::ty`.
     InlineConst(DefId, GenericArgsRef<'tcx>),
+
+    // Fake body for a global asm. Not particularly useful or interesting,
+    // but we need it so we can properly store the typeck results of the asm
+    // operands, which aren't associated with a body otherwise.
+    GlobalAsm(DefId),
 }
 
 impl<'tcx> DefiningTy<'tcx> {
@@ -138,9 +143,10 @@ impl<'tcx> DefiningTy<'tcx> {
             DefiningTy::Closure(_, args) => args.as_closure().upvar_tys(),
             DefiningTy::CoroutineClosure(_, args) => args.as_coroutine_closure().upvar_tys(),
             DefiningTy::Coroutine(_, args) => args.as_coroutine().upvar_tys(),
-            DefiningTy::FnDef(..) | DefiningTy::Const(..) | DefiningTy::InlineConst(..) => {
-                ty::List::empty()
-            }
+            DefiningTy::FnDef(..)
+            | DefiningTy::Const(..)
+            | DefiningTy::InlineConst(..)
+            | DefiningTy::GlobalAsm(_) => ty::List::empty(),
         }
     }
 
@@ -152,7 +158,10 @@ impl<'tcx> DefiningTy<'tcx> {
             DefiningTy::Closure(..)
             | DefiningTy::CoroutineClosure(..)
             | DefiningTy::Coroutine(..) => 1,
-            DefiningTy::FnDef(..) | DefiningTy::Const(..) | DefiningTy::InlineConst(..) => 0,
+            DefiningTy::FnDef(..)
+            | DefiningTy::Const(..)
+            | DefiningTy::InlineConst(..)
+            | DefiningTy::GlobalAsm(_) => 0,
         }
     }
 
@@ -171,7 +180,8 @@ impl<'tcx> DefiningTy<'tcx> {
             | DefiningTy::Coroutine(def_id, ..)
             | DefiningTy::FnDef(def_id, ..)
             | DefiningTy::Const(def_id, ..)
-            | DefiningTy::InlineConst(def_id, ..) => def_id,
+            | DefiningTy::InlineConst(def_id, ..)
+            | DefiningTy::GlobalAsm(def_id) => def_id,
         }
     }
 }
@@ -411,6 +421,7 @@ impl<'tcx> UniversalRegions<'tcx> {
                     tcx.def_path_str_with_args(def_id, args),
                 ));
             }
+            DefiningTy::GlobalAsm(_) => unreachable!(),
         }
     }
 
@@ -633,6 +644,8 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
                     DefiningTy::InlineConst(self.mir_def.to_def_id(), args)
                 }
             }
+
+            BodyOwnerKind::GlobalAsm => DefiningTy::GlobalAsm(self.mir_def.to_def_id()),
         }
     }
 
@@ -666,6 +679,8 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             }
 
             DefiningTy::FnDef(_, args) | DefiningTy::Const(_, args) => args,
+
+            DefiningTy::GlobalAsm(_) => ty::List::empty(),
         };
 
         let global_mapping = iter::once((tcx.lifetimes.re_static, fr_static));
@@ -802,6 +817,10 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
                 let ty = args.as_inline_const().ty();
                 ty::Binder::dummy(tcx.mk_type_list(&[ty]))
             }
+
+            DefiningTy::GlobalAsm(def_id) => {
+                ty::Binder::dummy(tcx.mk_type_list(&[tcx.type_of(def_id).instantiate_identity()]))
+            }
         };
 
         // FIXME(#129952): We probably want a more principled approach here.

compiler/rustc_codegen_cranelift/src/global_asm.rs

@@ -16,7 +16,7 @@ use crate::prelude::*;
 
 pub(crate) fn codegen_global_asm_item(tcx: TyCtxt<'_>, global_asm: &mut String, item_id: ItemId) {
     let item = tcx.hir_item(item_id);
-    if let rustc_hir::ItemKind::GlobalAsm(asm) = item.kind {
+    if let rustc_hir::ItemKind::GlobalAsm { asm, .. } = item.kind {
         let is_x86 =
             matches!(tcx.sess.asm_arch.unwrap(), InlineAsmArch::X86 | InlineAsmArch::X86_64);
 
@@ -55,15 +55,15 @@ pub(crate) fn codegen_global_asm_item(tcx: TyCtxt<'_>, global_asm: &mut String,
                                 }
                             }
                         }
-                        InlineAsmOperand::SymFn { anon_const } => {
+                        InlineAsmOperand::SymFn { expr } => {
                             if cfg!(not(feature = "inline_asm_sym")) {
                                 tcx.dcx().span_err(
                                     item.span,
                                     "asm! and global_asm! sym operands are not yet supported",
                                 );
                             }
 
-                            let ty = tcx.typeck_body(anon_const.body).node_type(anon_const.hir_id);
+                            let ty = tcx.typeck(item_id.owner_id).expr_ty(expr);
                             let instance = match ty.kind() {
                                 &ty::FnDef(def_id, args) => Instance::new(def_id, args),
                                 _ => span_bug!(op_sp, "asm sym is not a function"),

compiler/rustc_codegen_ssa/src/mono_item.rs

@@ -36,7 +36,7 @@ impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
             }
             MonoItem::GlobalAsm(item_id) => {
                 let item = cx.tcx().hir_item(item_id);
-                if let hir::ItemKind::GlobalAsm(asm) = item.kind {
+                if let hir::ItemKind::GlobalAsm { asm, .. } = item.kind {
                     let operands: Vec<_> = asm
                         .operands
                         .iter()
@@ -71,11 +71,8 @@ impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
                                     }
                                 }
                             }
-                            hir::InlineAsmOperand::SymFn { ref anon_const } => {
-                                let ty = cx
-                                    .tcx()
-                                    .typeck_body(anon_const.body)
-                                    .node_type(anon_const.hir_id);
+                            hir::InlineAsmOperand::SymFn { expr } => {
+                                let ty = cx.tcx().typeck(item_id.owner_id).expr_ty(expr);
                                 let instance = match ty.kind() {
                                     &ty::FnDef(def_id, args) => Instance::new(def_id, args),
                                     _ => span_bug!(*op_sp, "asm sym is not a function"),

compiler/rustc_errors/src/emitter.rs

@@ -2216,12 +2216,7 @@ impl HumanEmitter {
             if let DisplaySuggestion::Diff | DisplaySuggestion::Underline | DisplaySuggestion::Add =
                 show_code_change
             {
-                for mut part in parts {
-                    // If this is a replacement of, e.g. `"a"` into `"ab"`, adjust the
-                    // suggestion and snippet to look as if we just suggested to add
-                    // `"b"`, which is typically much easier for the user to understand.
-                    part.trim_trivial_replacements(sm);
-
+                for part in parts {
                     let snippet = if let Ok(snippet) = sm.span_to_snippet(part.span) {
                         snippet
                     } else {

compiler/rustc_errors/src/lib.rs

@@ -71,7 +71,7 @@ use rustc_macros::{Decodable, Encodable};
 pub use rustc_span::ErrorGuaranteed;
 pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
 use rustc_span::source_map::SourceMap;
-use rustc_span::{DUMMY_SP, Loc, Span};
+use rustc_span::{BytePos, DUMMY_SP, Loc, Span};
 pub use snippet::Style;
 // Used by external projects such as `rust-gpu`.
 // See https://github.com/rust-lang/rust/pull/115393.
@@ -237,10 +237,9 @@ impl SubstitutionPart {
     /// it with "abx" is, since the "c" character is lost.
     pub fn is_destructive_replacement(&self, sm: &SourceMap) -> bool {
         self.is_replacement(sm)
-            && !sm.span_to_snippet(self.span).is_ok_and(|snippet| {
-                self.snippet.trim_start().starts_with(snippet.trim_start())
-                    || self.snippet.trim_end().ends_with(snippet.trim_end())
-            })
+            && !sm
+                .span_to_snippet(self.span)
+                .is_ok_and(|snippet| as_substr(snippet.trim(), self.snippet.trim()).is_some())
     }
 
     fn replaces_meaningful_content(&self, sm: &SourceMap) -> bool {
@@ -257,16 +256,40 @@ impl SubstitutionPart {
         let Ok(snippet) = sm.span_to_snippet(self.span) else {
             return;
         };
-        if self.snippet.starts_with(&snippet) {
-            self.span = self.span.shrink_to_hi();
-            self.snippet = self.snippet[snippet.len()..].to_string();
-        } else if self.snippet.ends_with(&snippet) {
-            self.span = self.span.shrink_to_lo();
-            self.snippet = self.snippet[..self.snippet.len() - snippet.len()].to_string();
+
+        if let Some((prefix, substr, suffix)) = as_substr(&snippet, &self.snippet) {
+            self.span = Span::new(
+                self.span.lo() + BytePos(prefix as u32),
+                self.span.hi() - BytePos(suffix as u32),
+                self.span.ctxt(),
+                self.span.parent(),
+            );
+            self.snippet = substr.to_string();
         }
     }
 }
 
+/// Given an original string like `AACC`, and a suggestion like `AABBCC`, try to detect
+/// the case where a substring of the suggestion is "sandwiched" in the original, like
+/// `BB` is. Return the length of the prefix, the "trimmed" suggestion, and the length
+/// of the suffix.
+fn as_substr<'a>(original: &'a str, suggestion: &'a str) -> Option<(usize, &'a str, usize)> {
+    let common_prefix = original
+        .chars()
+        .zip(suggestion.chars())
+        .take_while(|(c1, c2)| c1 == c2)
+        .map(|(c, _)| c.len_utf8())
+        .sum();
+    let original = &original[common_prefix..];
+    let suggestion = &suggestion[common_prefix..];
+    if suggestion.ends_with(original) {
+        let common_suffix = original.len();
+        Some((common_prefix, &suggestion[..suggestion.len() - original.len()], common_suffix))
+    } else {
+        None
+    }
+}
+
 impl CodeSuggestion {
     /// Returns the assembled code suggestions, whether they should be shown with an underline
     /// and whether the substitution only differs in capitalization.
@@ -380,7 +403,12 @@ impl CodeSuggestion {
                 // or deleted code in order to point at the correct column *after* substitution.
                 let mut acc = 0;
                 let mut only_capitalization = false;
-                for part in &substitution.parts {
+                for part in &mut substitution.parts {
+                    // If this is a replacement of, e.g. `"a"` into `"ab"`, adjust the
+                    // suggestion and snippet to look as if we just suggested to add
+                    // `"b"`, which is typically much easier for the user to understand.
+                    part.trim_trivial_replacements(sm);
+
                     only_capitalization |= is_case_difference(sm, &part.snippet, part.span);
                     let cur_lo = sm.lookup_char_pos(part.span.lo());
                     if prev_hi.line == cur_lo.line {

compiler/rustc_feature/src/removed.rs

@@ -135,6 +135,8 @@ declare_features! (
      Some("removed as it caused some confusion and discussion was inactive for years")),
     /// Lazily evaluate constants. This allows constants to depend on type parameters.
     (removed, lazy_normalization_consts, "1.46.0", Some(72219), Some("superseded by `generic_const_exprs`")),
+    /// Changes `impl Trait` to capture all lifetimes in scope.
+    (removed, lifetime_capture_rules_2024, "1.76.0", None, Some("unnecessary -- use edition 2024 instead")),
     /// Allows using the `#[link_args]` attribute.
     (removed, link_args, "1.53.0", Some(29596),
      Some("removed in favor of using `-C link-arg=ARG` on command line, \

compiler/rustc_feature/src/unstable.rs

@@ -214,8 +214,6 @@ declare_features! (
     (internal, intrinsics, "1.0.0", None),
     /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
     (internal, lang_items, "1.0.0", None),
-    /// Changes `impl Trait` to capture all lifetimes in scope.
-    (unstable, lifetime_capture_rules_2024, "1.76.0", None),
     /// Allows `#[link(..., cfg(..))]`; perma-unstable per #37406
     (internal, link_cfg, "1.14.0", None),
     /// Allows using `?Trait` trait bounds in more contexts.

compiler/rustc_hir/src/hir.rs

@@ -1913,13 +1913,18 @@ pub enum BodyOwnerKind {
 
     /// Initializer of a `static` item.
     Static(Mutability),
+
+    /// Fake body for a global asm to store its const-like value types.
+    GlobalAsm,
 }
 
 impl BodyOwnerKind {
     pub fn is_fn_or_closure(self) -> bool {
         match self {
             BodyOwnerKind::Fn | BodyOwnerKind::Closure => true,
-            BodyOwnerKind::Const { .. } | BodyOwnerKind::Static(_) => false,
+            BodyOwnerKind::Const { .. } | BodyOwnerKind::Static(_) | BodyOwnerKind::GlobalAsm => {
+                false
+            }
         }
     }
 }
@@ -3420,7 +3425,7 @@ pub enum InlineAsmOperand<'hir> {
         anon_const: &'hir AnonConst,
     },
     SymFn {
-        anon_const: &'hir AnonConst,
+        expr: &'hir Expr<'hir>,
     },
     SymStatic {
         path: QPath<'hir>,
@@ -3848,7 +3853,7 @@ impl<'hir> Item<'hir> {
         expect_foreign_mod, (ExternAbi, &'hir [ForeignItemRef]),
             ItemKind::ForeignMod { abi, items }, (*abi, items);
 
-        expect_global_asm, &'hir InlineAsm<'hir>, ItemKind::GlobalAsm(asm), asm;
+        expect_global_asm, &'hir InlineAsm<'hir>, ItemKind::GlobalAsm { asm, .. }, asm;
 
         expect_ty_alias, (&'hir Ty<'hir>, &'hir Generics<'hir>),
             ItemKind::TyAlias(ty, generics), (ty, generics);
@@ -4015,7 +4020,15 @@ pub enum ItemKind<'hir> {
     /// An external module, e.g. `extern { .. }`.
     ForeignMod { abi: ExternAbi, items: &'hir [ForeignItemRef] },
     /// Module-level inline assembly (from `global_asm!`).
-    GlobalAsm(&'hir InlineAsm<'hir>),
+    GlobalAsm {
+        asm: &'hir InlineAsm<'hir>,
+        /// A fake body which stores typeck results for the global asm's sym_fn
+        /// operands, which are represented as path expressions. This body contains
+        /// a single [`ExprKind::InlineAsm`] which points to the asm in the field
+        /// above, and which is typechecked like a inline asm expr just for the
+        /// typeck results.
+        fake_body: BodyId,
+    },
     /// A type alias, e.g., `type Foo = Bar<u8>`.
     TyAlias(&'hir Ty<'hir>, &'hir Generics<'hir>),
     /// An enum definition, e.g., `enum Foo<A, B> {C<A>, D<B>}`.
@@ -4081,7 +4094,7 @@ impl ItemKind<'_> {
             ItemKind::Macro(..) => "macro",
             ItemKind::Mod(..) => "module",
             ItemKind::ForeignMod { .. } => "extern block",
-            ItemKind::GlobalAsm(..) => "global asm item",
+            ItemKind::GlobalAsm { .. } => "global asm item",
             ItemKind::TyAlias(..) => "type alias",
             ItemKind::Enum(..) => "enum",
             ItemKind::Struct(..) => "struct",
@@ -4540,6 +4553,10 @@ impl<'hir> Node<'hir> {
                 ..
             }) => Some((owner_id.def_id, *body)),
 
+            Node::Item(Item {
+                owner_id, kind: ItemKind::GlobalAsm { asm: _, fake_body }, ..
+            }) => Some((owner_id.def_id, *fake_body)),
+
             Node::Expr(Expr { kind: ExprKind::Closure(Closure { def_id, body, .. }), .. }) => {
                 Some((*def_id, *body))
             }