Rollup of 13 pull requests

.github/ISSUE_TEMPLATE/ice.md

@@ -0,0 +1,49 @@
+---
+name: Internal Compiler Error
+about: Create a report for an internal compiler error in rustc.
+labels: C-bug, I-ICE, T-compiler
+---
+<!--
+Thank you for finding an Internal Compiler Error! 🧊  If possible, try to provide
+a minimal verifiable example. You can read "Rust Bug Minimization Patterns" for
+how to create smaller examples.
+http://blog.pnkfx.org/blog/2019/11/18/rust-bug-minimization-patterns/
+-->
+
+### Code
+
+```Rust
+<code>
+```
+
+
+### Meta
+<!--
+If you're using the stable version of the compiler, you should also check if the
+bug also exists in the beta or nightly versions.
+-->
+
+`rustc --version --verbose`:
+```
+<version>
+```
+
+### Error output
+
+```
+<output>
+```
+
+<!--
+Include a backtrace in the code block by setting `RUST_BACKTRACE=1` in your
+environment. E.g. `RUST_BACKTRACE=1 cargo build`.
+-->
+<details><summary><strong>Backtrace</strong></summary>
+<p>
+
+```
+<backtrace>
+```
+
+</p>
+</details>

.github/ISSUE_TEMPLATE/ice.yaml

@@ -1,5 +1,5 @@
-name: Internal Compiler Error
-description: Create a report for an internal compiler error in `rustc`
+name: Internal Compiler Error (Structured form)
+description: For now, you'll want to use the other ICE template, as GitHub forms have strict limits on the size of fields so backtraces cannot be pasted directly.
 labels: ["C-bug", "I-ICE", "T-compiler"]
 title: "[ICE]: "
 body:
@@ -79,4 +79,4 @@ body:
       label: Anything else?
       description: If you have more details you want to give us to reproduce this issue, please add it here
     validations:
-      required: false
+      required: false

compiler/rustc_abi/src/lib.rs

@@ -1456,6 +1456,8 @@ pub enum PointerKind {
     UniqueOwned,
 }
 
+/// Note that this information is advisory only, and backends are free to ignore it.
+/// It can only be used to encode potential optimizations, but no critical information.
 #[derive(Copy, Clone, Debug)]
 pub struct PointeeInfo {
     pub size: Size,

compiler/rustc_ast/src/util/comments.rs

@@ -58,23 +58,24 @@ pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
         // In case we have doc comments like `/**` or `/*!`, we want to remove stars if they are
         // present. However, we first need to strip the empty lines so they don't get in the middle
         // when we try to compute the "horizontal trim".
-        let lines = if kind == CommentKind::Block {
-            // Whatever happens, we skip the first line.
-            let mut i = lines
-                .get(0)
-                .map(|l| if l.trim_start().starts_with('*') { 0 } else { 1 })
-                .unwrap_or(0);
-            let mut j = lines.len();
-
-            while i < j && lines[i].trim().is_empty() {
-                i += 1;
-            }
-            while j > i && lines[j - 1].trim().is_empty() {
-                j -= 1;
+        let lines = match kind {
+            CommentKind::Block => {
+                // Whatever happens, we skip the first line.
+                let mut i = lines
+                    .get(0)
+                    .map(|l| if l.trim_start().starts_with('*') { 0 } else { 1 })
+                    .unwrap_or(0);
+                let mut j = lines.len();
+
+                while i < j && lines[i].trim().is_empty() {
+                    i += 1;
+                }
+                while j > i && lines[j - 1].trim().is_empty() {
+                    j -= 1;
+                }
+                &lines[i..j]
             }
-            &lines[i..j]
-        } else {
-            lines
+            CommentKind::Line => lines,
         };
 
         for line in lines {

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -131,7 +131,7 @@ pub fn print_crate<'a>(
 
         // Currently, in Rust 2018 we don't have `extern crate std;` at the crate
         // root, so this is not needed, and actually breaks things.
-        if edition == Edition::Edition2015 {
+        if edition.rust_2015() {
             // `#![no_std]`
             let fake_attr = attr::mk_attr_word(g, ast::AttrStyle::Inner, sym::no_std, DUMMY_SP);
             s.print_attribute(&fake_attr);

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -344,7 +344,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     } else {
                         err.span_help(source_info.span, "try removing `&mut` here");
                     }
-                } else if decl.mutability == Mutability::Not {
+                } else if decl.mutability.is_not() {
                     if matches!(
                         decl.local_info,
                         Some(box LocalInfo::User(ClearCrossCrate::Set(BindingForm::ImplicitSelf(

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -2028,7 +2028,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                             }
                         };
 
-                        if ty_to_mut == Mutability::Mut && ty_mut == Mutability::Not {
+                        if ty_to_mut.is_mut() && ty_mut.is_not() {
                             span_mirbug!(
                                 self,
                                 rvalue,

compiler/rustc_codegen_llvm/src/context.rs

@@ -150,17 +150,14 @@ pub unsafe fn create_module<'ll>(
             target_data_layout =
                 "e-m:x-p:32:32-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:32-n8:16:32-a:0:32-S32"
                     .to_string();
-        }
-        if sess.target.arch == "wasm32" {
+        } else if sess.target.arch == "wasm32" {
             target_data_layout = target_data_layout.replace("-p10:8:8-p20:8:8", "");
         }
     }
     if llvm_version < (16, 0, 0) {
         if sess.target.arch == "s390x" {
             target_data_layout = target_data_layout.replace("-v128:64", "");
-        }
-
-        if sess.target.arch == "riscv64" {
+        } else if sess.target.arch == "riscv64" {
             target_data_layout = target_data_layout.replace("-n32:64-", "-n64-");
         }
     }

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -622,10 +622,9 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
         let alloc = alloc.inner();
         if is_write {
             // Write access. These are never allowed, but we give a targeted error message.
-            if alloc.mutability == Mutability::Not {
-                Err(err_ub!(WriteToReadOnly(alloc_id)).into())
-            } else {
-                Err(ConstEvalErrKind::ModifiedGlobal.into())
+            match alloc.mutability {
+                Mutability::Not => Err(err_ub!(WriteToReadOnly(alloc_id)).into()),
+                Mutability::Mut => Err(ConstEvalErrKind::ModifiedGlobal.into()),
             }
         } else {
             // Read access. These are usually allowed, with some exceptions.

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -304,7 +304,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             .into());
         };
 
-        if alloc.mutability == Mutability::Not {
+        if alloc.mutability.is_not() {
             throw_ub_format!("deallocating immutable allocation {alloc_id:?}");
         }
         if alloc_kind != kind {
@@ -631,7 +631,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         }
 
         let (_kind, alloc) = self.memory.alloc_map.get_mut(id).unwrap();
-        if alloc.mutability == Mutability::Not {
+        if alloc.mutability.is_not() {
             throw_ub!(WriteToReadOnly(id))
         }
         Ok((alloc, &mut self.machine))

compiler/rustc_const_eval/src/transform/validate.rs

@@ -754,7 +754,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 // FIXME(JakobDegen) The validator should check that `self.mir_phase <
                 // DropsLowered`. However, this causes ICEs with generation of drop shims, which
                 // seem to fail to set their `MirPhase` correctly.
-                if *kind == RetagKind::Raw || *kind == RetagKind::TwoPhase {
+                if matches!(kind, RetagKind::Raw | RetagKind::TwoPhase) {
                     self.fail(location, format!("explicit `{:?}` is forbidden", kind));
                 }
             }

compiler/rustc_errors/src/emitter.rs

@@ -2113,30 +2113,38 @@ impl EmitterWriter {
                         }
                     }
                     for sugg in suggestions {
-                        if sugg.style == SuggestionStyle::CompletelyHidden {
-                            // do not display this suggestion, it is meant only for tools
-                        } else if sugg.style == SuggestionStyle::HideCodeAlways {
-                            if let Err(e) = self.emit_message_default(
-                                &MultiSpan::new(),
-                                &[(sugg.msg.to_owned(), Style::HeaderMsg)],
-                                args,
-                                &None,
-                                &Level::Help,
-                                max_line_num_len,
-                                true,
-                                None,
-                            ) {
-                                panic!("failed to emit error: {}", e);
+                        match sugg.style {
+                            SuggestionStyle::CompletelyHidden => {
+                                // do not display this suggestion, it is meant only for tools
                             }
-                        } else if let Err(e) = self.emit_suggestion_default(
-                            span,
-                            sugg,
-                            args,
-                            &Level::Help,
-                            max_line_num_len,
-                        ) {
-                            panic!("failed to emit error: {}", e);
-                        };
+                            SuggestionStyle::HideCodeAlways => {
+                                if let Err(e) = self.emit_message_default(
+                                    &MultiSpan::new(),
+                                    &[(sugg.msg.to_owned(), Style::HeaderMsg)],
+                                    args,
+                                    &None,
+                                    &Level::Help,
+                                    max_line_num_len,
+                                    true,
+                                    None,
+                                ) {
+                                    panic!("failed to emit error: {}", e);
+                                }
+                            }
+                            SuggestionStyle::HideCodeInline
+                            | SuggestionStyle::ShowCode
+                            | SuggestionStyle::ShowAlways => {
+                                if let Err(e) = self.emit_suggestion_default(
+                                    span,
+                                    sugg,
+                                    args,
+                                    &Level::Help,
+                                    max_line_num_len,
+                                ) {
+                                    panic!("failed to emit error: {}", e);
+                                }
+                            }
+                        }
                     }
                 }
             }

compiler/rustc_errors/src/styled_buffer.rs

@@ -142,7 +142,7 @@ impl StyledBuffer {
     pub fn set_style(&mut self, line: usize, col: usize, style: Style, overwrite: bool) {
         if let Some(ref mut line) = self.lines.get_mut(line) {
             if let Some(StyledChar { style: s, .. }) = line.get_mut(col) {
-                if overwrite || *s == Style::NoStyle || *s == Style::Quotation {
+                if overwrite || matches!(s, Style::NoStyle | Style::Quotation) {
                     *s = style;
                 }
             }

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -503,7 +503,7 @@ impl TtParser {
                         mp.push_match(metavar_idx, seq_depth, MatchedSeq(vec![]));
                     }
 
-                    if op == KleeneOp::ZeroOrMore || op == KleeneOp::ZeroOrOne {
+                    if matches!(op, KleeneOp::ZeroOrMore | KleeneOp::ZeroOrOne) {
                         // Try zero matches of this sequence, by skipping over it.
                         self.cur_mps.push(MatcherPos {
                             idx: idx_first_after,

compiler/rustc_hir_analysis/src/astconv/generics.rs

@@ -385,10 +385,9 @@ pub fn check_generic_arg_count_for_call(
 ) -> GenericArgCountResult {
     let empty_args = hir::GenericArgs::none();
     let gen_args = seg.args.unwrap_or(&empty_args);
-    let gen_pos = if is_method_call == IsMethodCall::Yes {
-        GenericArgPosition::MethodCall
-    } else {
-        GenericArgPosition::Value
+    let gen_pos = match is_method_call {
+        IsMethodCall::Yes => GenericArgPosition::MethodCall,
+        IsMethodCall::No => GenericArgPosition::Value,
     };
     let has_self = generics.parent.is_none() && generics.has_self;