Auto merge of #150068 - JonathanBrouwer:rollup-45j7puz, r=JonathanBrouwer

Rollup of 11 pull requests

Successful merges:

 - #147939 (Make `const BorrowMut` require `const Borrow` and make `const Fn` require `const FnMut`)
 - #149734 (Mirror GCC 9.5.0)
 - #149767 (Tidying up tests/ui/issues 33 tests [4/N])
 - #149804 (chore: fix some minor issues in the comments)
 - #149967 (custom `VaList` layout for Hexagon)
 - #150025 (dont create unnecessary `DefId`s under mgca)
 - #150032 (Use annotate-snippet as default emitter on stable)
 - #150033 (Add try_as_dyn and try_as_dyn_mut)
 - #150042 (rustc-dev-guide subtree update)
 - #150063 (Remove deny of manual-let-else)
 - #150064 (std: io: error: Add comment for UEFI unpacked repr use)

Failed merges:

 - #150044 (Avoid unhelpful suggestion when crate name is invalid)

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

Author: bors

compiler/rustc_ast/src/lib.rs

@@ -6,7 +6,6 @@
 
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(array_windows))]
-#![deny(clippy::manual_let_else)]
 #![doc(test(attr(deny(warnings), allow(internal_features))))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]

compiler/rustc_borrowck/src/lib.rs

@@ -2,7 +2,6 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
-#![deny(clippy::manual_let_else)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -6,14 +6,17 @@ mod simd;
 
 use std::assert_matches::assert_matches;
 
-use rustc_abi::{FieldIdx, HasDataLayout, Size, VariantIdx};
+use rustc_abi::{FIRST_VARIANT, FieldIdx, HasDataLayout, Size, VariantIdx};
 use rustc_apfloat::ieee::{Double, Half, Quad, Single};
+use rustc_hir::def_id::CRATE_DEF_ID;
+use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::mir::interpret::{CTFE_ALLOC_SALT, read_target_uint, write_target_uint};
 use rustc_middle::mir::{self, BinOp, ConstValue, NonDivergingIntrinsic};
 use rustc_middle::ty::layout::TyAndLayout;
-use rustc_middle::ty::{FloatTy, Ty, TyCtxt};
+use rustc_middle::ty::{FloatTy, PolyExistentialPredicate, Ty, TyCtxt, TypeFoldable};
 use rustc_middle::{bug, span_bug, ty};
 use rustc_span::{Symbol, sym};
+use rustc_trait_selection::traits::{Obligation, ObligationCause, ObligationCtxt};
 use tracing::trace;
 
 use super::memory::MemoryKind;
@@ -219,6 +222,49 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
 
                 self.write_scalar(Scalar::from_target_usize(offset, self), dest)?;
             }
+            sym::vtable_for => {
+                let tp_ty = instance.args.type_at(0);
+                let result_ty = instance.args.type_at(1);
+
+                ensure_monomorphic_enough(tcx, tp_ty)?;
+                ensure_monomorphic_enough(tcx, result_ty)?;
+                let ty::Dynamic(preds, _) = result_ty.kind() else {
+                    span_bug!(
+                        self.find_closest_untracked_caller_location(),
+                        "Invalid type provided to vtable_for::<T, U>. U must be dyn Trait, got {result_ty}."
+                    );
+                };
+
+                let (infcx, param_env) =
+                    self.tcx.infer_ctxt().build_with_typing_env(self.typing_env);
+
+                let ocx = ObligationCtxt::new(&infcx);
+                ocx.register_obligations(preds.iter().map(|pred: PolyExistentialPredicate<'_>| {
+                    let pred = pred.with_self_ty(tcx, tp_ty);
+                    // Lifetimes can only be 'static because of the bound on T
+                    let pred = pred.fold_with(&mut ty::BottomUpFolder {
+                        tcx,
+                        ty_op: |ty| ty,
+                        lt_op: |lt| {
+                            if lt == tcx.lifetimes.re_erased { tcx.lifetimes.re_static } else { lt }
+                        },
+                        ct_op: |ct| ct,
+                    });
+                    Obligation::new(tcx, ObligationCause::dummy(), param_env, pred)
+                }));
+                let type_impls_trait = ocx.evaluate_obligations_error_on_ambiguity().is_empty();
+                // Since `assumed_wf_tys=[]` the choice of LocalDefId is irrelevant, so using the "default"
+                let regions_are_valid = ocx.resolve_regions(CRATE_DEF_ID, param_env, []).is_empty();
+
+                if regions_are_valid && type_impls_trait {
+                    let vtable_ptr = self.get_vtable_ptr(tp_ty, preds)?;
+                    // Writing a non-null pointer into an `Option<NonNull>` will automatically make it `Some`.
+                    self.write_pointer(vtable_ptr, dest)?;
+                } else {
+                    // Write `None`
+                    self.write_discriminant(FIRST_VARIANT, dest)?;
+                }
+            }
             sym::variant_count => {
                 let tp_ty = instance.args.type_at(0);
                 let ty = match tp_ty.kind() {

compiler/rustc_const_eval/src/lib.rs

@@ -1,6 +1,5 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
-#![deny(clippy::manual_let_else)]
 #![feature(array_try_map)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]

compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs

@@ -303,17 +303,6 @@ impl AnnotateSnippetEmitter {
             }
         }
 
-        let suggestions_expected = suggestions
-            .iter()
-            .filter(|s| {
-                matches!(
-                    s.style,
-                    SuggestionStyle::HideCodeInline
-                        | SuggestionStyle::ShowCode
-                        | SuggestionStyle::ShowAlways
-                )
-            })
-            .count();
         for suggestion in suggestions {
             match suggestion.style {
                 SuggestionStyle::CompletelyHidden => {
@@ -526,12 +515,6 @@ impl AnnotateSnippetEmitter {
             }
         }
 
-        // FIXME: This hack should be removed once annotate_snippets is the
-        // default emitter.
-        if suggestions_expected > 0 && report.is_empty() {
-            group = group.element(Padding);
-        }
-
         if !group.is_empty() {
             report.push(group);
         }

compiler/rustc_errors/src/emitter.rs

@@ -46,17 +46,14 @@ const DEFAULT_COLUMN_WIDTH: usize = 140;
 
 /// Describes the way the content of the `rendered` field of the json output is generated
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum HumanReadableErrorType {
-    Default { short: bool },
-    AnnotateSnippet { short: bool, unicode: bool },
+pub struct HumanReadableErrorType {
+    pub short: bool,
+    pub unicode: bool,
 }
 
 impl HumanReadableErrorType {
     pub fn short(&self) -> bool {
-        match self {
-            HumanReadableErrorType::Default { short }
-            | HumanReadableErrorType::AnnotateSnippet { short, .. } => *short,
-        }
+        self.short
     }
 }
 
@@ -607,7 +604,7 @@ pub enum OutputTheme {
     Unicode,
 }
 
-/// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
+/// Handles the writing of `HumanReadableErrorType`
 #[derive(Setters)]
 pub struct HumanEmitter {
     #[setters(skip)]

compiler/rustc_errors/src/json.rs

@@ -28,8 +28,8 @@ use serde::Serialize;
 use crate::annotate_snippet_emitter_writer::AnnotateSnippetEmitter;
 use crate::diagnostic::IsLint;
 use crate::emitter::{
-    ColorConfig, Destination, Emitter, HumanEmitter, HumanReadableErrorType, OutputTheme,
-    TimingEvent, should_show_source_code,
+    ColorConfig, Destination, Emitter, HumanReadableErrorType, OutputTheme, TimingEvent,
+    should_show_source_code,
 };
 use crate::registry::Registry;
 use crate::timings::{TimingRecord, TimingSection};
@@ -378,38 +378,17 @@ impl Diagnostic {
                 choice => choice,
             },
         );
-        match je.json_rendered {
-            HumanReadableErrorType::AnnotateSnippet { short, unicode } => {
-                AnnotateSnippetEmitter::new(dst, je.translator.clone())
-                    .short_message(short)
-                    .sm(je.sm.clone())
-                    .diagnostic_width(je.diagnostic_width)
-                    .macro_backtrace(je.macro_backtrace)
-                    .track_diagnostics(je.track_diagnostics)
-                    .terminal_url(je.terminal_url)
-                    .ui_testing(je.ui_testing)
-                    .ignored_directories_in_source_blocks(
-                        je.ignored_directories_in_source_blocks.clone(),
-                    )
-                    .theme(if unicode { OutputTheme::Unicode } else { OutputTheme::Ascii })
-                    .emit_diagnostic(diag, registry)
-            }
-            HumanReadableErrorType::Default { short } => {
-                HumanEmitter::new(dst, je.translator.clone())
-                    .short_message(short)
-                    .sm(je.sm.clone())
-                    .diagnostic_width(je.diagnostic_width)
-                    .macro_backtrace(je.macro_backtrace)
-                    .track_diagnostics(je.track_diagnostics)
-                    .terminal_url(je.terminal_url)
-                    .ui_testing(je.ui_testing)
-                    .ignored_directories_in_source_blocks(
-                        je.ignored_directories_in_source_blocks.clone(),
-                    )
-                    .theme(OutputTheme::Ascii)
-                    .emit_diagnostic(diag, registry)
-            }
-        }
+        AnnotateSnippetEmitter::new(dst, je.translator.clone())
+            .short_message(je.json_rendered.short)
+            .sm(je.sm.clone())
+            .diagnostic_width(je.diagnostic_width)
+            .macro_backtrace(je.macro_backtrace)
+            .track_diagnostics(je.track_diagnostics)
+            .terminal_url(je.terminal_url)
+            .ui_testing(je.ui_testing)
+            .ignored_directories_in_source_blocks(je.ignored_directories_in_source_blocks.clone())
+            .theme(if je.json_rendered.unicode { OutputTheme::Unicode } else { OutputTheme::Ascii })
+            .emit_diagnostic(diag, registry);
 
         let buf = Arc::try_unwrap(buf.0).unwrap().into_inner().unwrap();
         let buf = String::from_utf8(buf).unwrap();

compiler/rustc_errors/src/json/tests.rs

@@ -54,7 +54,7 @@ fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
             Some(sm),
             translator,
             true, // pretty
-            HumanReadableErrorType::Default { short: true },
+            HumanReadableErrorType { short: true, unicode: false },
             ColorConfig::Never,
         );
 

compiler/rustc_hir/src/lib.rs

@@ -4,7 +4,6 @@
 
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(debug_closure_helpers))]
-#![deny(clippy::manual_let_else)]
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
 #![feature(const_default)]

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -215,6 +215,7 @@ fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hi
         | sym::type_name
         | sym::ub_checks
         | sym::variant_count
+        | sym::vtable_for
         | sym::wrapping_add
         | sym::wrapping_mul
         | sym::wrapping_sub
@@ -643,6 +644,20 @@ pub(crate) fn check_intrinsic_type(
             (0, 0, vec![Ty::new_imm_ptr(tcx, tcx.types.unit)], tcx.types.usize)
         }
 
+        sym::vtable_for => {
+            let dyn_metadata = tcx.require_lang_item(LangItem::DynMetadata, span);
+            let dyn_metadata_adt_ref = tcx.adt_def(dyn_metadata);
+            let dyn_metadata_args = tcx.mk_args(&[param(1).into()]);
+            let dyn_ty = Ty::new_adt(tcx, dyn_metadata_adt_ref, dyn_metadata_args);
+
+            let option_did = tcx.require_lang_item(LangItem::Option, span);
+            let option_adt_ref = tcx.adt_def(option_did);
+            let option_args = tcx.mk_args(&[dyn_ty.into()]);
+            let ret_ty = Ty::new_adt(tcx, option_adt_ref, option_args);
+
+            (2, 0, vec![], ret_ty)
+        }
+
         // This type check is not particularly useful, but the `where` bounds
         // on the definition in `core` do the heavy lifting for checking it.
         sym::aggregate_raw_ptr => (3, 0, vec![param(1), param(2)], param(0)),