Auto merge of rust-lang#93119 - matthiaskrgr:rollup-ku3cn5j, r=matthi…

…askrgr

Rollup of 13 pull requests

Successful merges:

 - rust-lang#89747 (Add MaybeUninit::(slice_)as_bytes(_mut))
 - rust-lang#89764 (Fix variant index / discriminant confusion in uninhabited enum branching)
 - rust-lang#91606 (Stabilize `-Z print-link-args` as `--print link-args`)
 - rust-lang#91694 (rustdoc: decouple stability and const-stability)
 - rust-lang#92183 (Point at correct argument when async fn output type lifetime disagrees with signature)
 - rust-lang#92582 (improve `_` constants in item signature handling)
 - rust-lang#92680 (intra-doc: Use the impl's assoc item where possible)
 - rust-lang#92704 (Change lint message to be stronger for &T -> &mut T transmute)
 - rust-lang#92861 (Rustdoc mobile: put out-of-band info on its own line)
 - rust-lang#92992 (Help optimize out backtraces when disabled)
 - rust-lang#93038 (Fix star handling in block doc comments)
 - rust-lang#93108 (:arrow_up: rust-analyzer)
 - rust-lang#93112 (Fix CVE-2022-21658)

Failed merges:

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

compiler/rustc_ast/src/attr/mod.rs

@@ -242,6 +242,17 @@ impl Attribute {
  }
  }
 
+ pub fn doc_str_and_comment_kind(&self) -> Option<(Symbol, CommentKind)> {
+ match self.kind {
+ AttrKind::DocComment(kind, data) => Some((data, kind)),
+ AttrKind::Normal(ref item, _) if item.path == sym::doc => item
+ .meta_kind()
+ .and_then(|kind| kind.value_str())
+ .map(|data| (data, CommentKind::Line)),
+ _ => None,
+ }
+ }
+
  pub fn doc_str(&self) -> Option<Symbol> {
  match self.kind {
  AttrKind::DocComment(.., data) => Some(data),

compiler/rustc_ast/src/util/comments.rs

@@ -1,3 +1,4 @@
+use crate::token::CommentKind;
 use rustc_span::source_map::SourceMap;
 use rustc_span::{BytePos, CharPos, FileName, Pos, Symbol};
 
@@ -25,7 +26,7 @@ pub struct Comment {
 
 /// Makes a doc string more presentable to users.
 /// Used by rustdoc and perhaps other tools, but not by rustc.
-pub fn beautify_doc_string(data: Symbol) -> Symbol {
+pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
  fn get_vertical_trim(lines: &[&str]) -> Option<(usize, usize)> {
  let mut i = 0;
  let mut j = lines.len();
@@ -42,10 +43,28 @@ pub fn beautify_doc_string(data: Symbol) -> Symbol {
  if i != 0 || j != lines.len() { Some((i, j)) } else { None }
  }
 
- fn get_horizontal_trim(lines: &[&str]) -> Option<usize> {
+ fn get_horizontal_trim(lines: &[&str], kind: CommentKind) -> Option<usize> {
  let mut i = usize::MAX;
  let mut first = true;
 
+ // 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 {
+ let mut i = 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]
+ } else {
+ lines
+ };
+
  for line in lines {
  for (j, c) in line.chars().enumerate() {
  if j > i || !"* \t".contains(c) {
@@ -79,11 +98,13 @@ pub fn beautify_doc_string(data: Symbol) -> Symbol {
  } else {
  &mut lines
  };
- if let Some(horizontal) = get_horizontal_trim(&lines) {
+ if let Some(horizontal) = get_horizontal_trim(&lines, kind) {
  changes = true;
  // remove a "[ \t]*\*" block from each line, if possible
  for line in lines.iter_mut() {
- *line = &line[horizontal + 1..];
+ if horizontal + 1 < line.len() {
+ *line = &line[horizontal + 1..];
+ }
  }
  }
  if changes {

compiler/rustc_ast/src/util/comments/tests.rs

@@ -5,7 +5,7 @@ use rustc_span::create_default_session_globals_then;
 fn test_block_doc_comment_1() {
  create_default_session_globals_then(|| {
  let comment = "\n * Test \n ** Test\n * Test\n";
- let stripped = beautify_doc_string(Symbol::intern(comment));
+ let stripped = beautify_doc_string(Symbol::intern(comment), CommentKind::Block);
  assert_eq!(stripped.as_str(), " Test \n* Test\n Test");
  })
 }
@@ -14,7 +14,7 @@ fn test_block_doc_comment_1() {
 fn test_block_doc_comment_2() {
  create_default_session_globals_then(|| {
  let comment = "\n * Test\n * Test\n";
- let stripped = beautify_doc_string(Symbol::intern(comment));
+ let stripped = beautify_doc_string(Symbol::intern(comment), CommentKind::Block);
  assert_eq!(stripped.as_str(), " Test\n Test");
  })
 }
@@ -23,21 +23,21 @@ fn test_block_doc_comment_2() {
 fn test_block_doc_comment_3() {
  create_default_session_globals_then(|| {
  let comment = "\n let a: *i32;\n *a = 5;\n";
- let stripped = beautify_doc_string(Symbol::intern(comment));
+ let stripped = beautify_doc_string(Symbol::intern(comment), CommentKind::Block);
  assert_eq!(stripped.as_str(), " let a: *i32;\n *a = 5;");
  })
 }
 
 #[test]
 fn test_line_doc_comment() {
  create_default_session_globals_then(|| {
- let stripped = beautify_doc_string(Symbol::intern(" test"));
+ let stripped = beautify_doc_string(Symbol::intern(" test"), CommentKind::Line);
  assert_eq!(stripped.as_str(), " test");
- let stripped = beautify_doc_string(Symbol::intern("! test"));
+ let stripped = beautify_doc_string(Symbol::intern("! test"), CommentKind::Line);
  assert_eq!(stripped.as_str(), "! test");
- let stripped = beautify_doc_string(Symbol::intern("test"));
+ let stripped = beautify_doc_string(Symbol::intern("test"), CommentKind::Line);
  assert_eq!(stripped.as_str(), "test");
- let stripped = beautify_doc_string(Symbol::intern("!test"));
+ let stripped = beautify_doc_string(Symbol::intern("!test"), CommentKind::Line);
  assert_eq!(stripped.as_str(), "!test");
  })
 }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -667,7 +667,7 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
  cmd.env_remove(k);
  }
 
- if sess.opts.debugging_opts.print_link_args {
+ if sess.opts.prints.contains(&PrintRequest::LinkArgs) {
  println!("{:?}", &cmd);
  }
 

compiler/rustc_driver/src/lib.rs

@@ -645,9 +645,9 @@ impl RustcDefaultCalls {
  temps_dir: &Option<PathBuf>,
  ) -> Compilation {
  use rustc_session::config::PrintRequest::*;
- // PrintRequest::NativeStaticLibs is special - printed during linking
+ // NativeStaticLibs and LinkArgs are special - printed during linking
  // (empty iterator returns true)
- if sess.opts.prints.iter().all(|&p| p == PrintRequest::NativeStaticLibs) {
+ if sess.opts.prints.iter().all(|&p| p == NativeStaticLibs || p == LinkArgs) {
  return Compilation::Continue;
  }
 
@@ -738,7 +738,8 @@ impl RustcDefaultCalls {
  codegen_backend.print(*req, sess);
  }
  // Any output here interferes with Cargo's parsing of other printed output
- PrintRequest::NativeStaticLibs => {}
+ NativeStaticLibs => {}
+ LinkArgs => {}
  }
  }
  Compilation::Stop

compiler/rustc_hir/src/hir.rs

@@ -2726,6 +2726,10 @@ pub struct FnHeader {
 }
 
 impl FnHeader {
+ pub fn is_async(&self) -> bool {
+ matches!(&self.asyncness, IsAsync::Async)
+ }
+
  pub fn is_const(&self) -> bool {
  matches!(&self.constness, Constness::Const)
  }
@@ -3169,7 +3173,7 @@ impl<'hir> Node<'hir> {
  }
  }
 
- pub fn fn_decl(&self) -> Option<&FnDecl<'hir>> {
+ pub fn fn_decl(&self) -> Option<&'hir FnDecl<'hir>> {
  match self {
  Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
  | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
@@ -3181,6 +3185,15 @@ impl<'hir> Node<'hir> {
  }
  }
 
+ pub fn fn_sig(&self) -> Option<&'hir FnSig<'hir>> {
+ match self {
+ Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
+ | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
+ | Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig),
+ _ => None,
+ }
+ }
+
  pub fn body_id(&self) -> Option<BodyId> {
  match self {
  Node::TraitItem(TraitItem {

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -65,11 +65,11 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{Item, ItemKind, Node};
 use rustc_middle::dep_graph::DepContext;
-use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::{
  self,
+ error::TypeError,
  subst::{GenericArgKind, Subst, SubstsRef},
- Region, Ty, TyCtxt, TypeFoldable,
+ Binder, Region, Ty, TyCtxt, TypeFoldable,
 };
 use rustc_span::{sym, BytePos, DesugaringKind, MultiSpan, Pos, Span};
 use rustc_target::spec::abi;
@@ -1765,7 +1765,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
  self.note_error_origin(diag, cause, exp_found, terr);
  }
 
- pub fn get_impl_future_output_ty(&self, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
+ pub fn get_impl_future_output_ty(&self, ty: Ty<'tcx>) -> Option<Binder<'tcx, Ty<'tcx>>> {
  if let ty::Opaque(def_id, substs) = ty.kind() {
  let future_trait = self.tcx.require_lang_item(LangItem::Future, None);
  // Future::Output
@@ -1775,13 +1775,20 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
 
  for (predicate, _) in bounds {
  let predicate = predicate.subst(self.tcx, substs);
- if let ty::PredicateKind::Projection(projection_predicate) =
- predicate.kind().skip_binder()
- {
- if projection_predicate.projection_ty.item_def_id == item_def_id {
- // We don't account for multiple `Future::Output = Ty` contraints.
- return projection_predicate.term.ty();
- }
+ let output = predicate
+ .kind()
+ .map_bound(|kind| match kind {
+ ty::PredicateKind::Projection(projection_predicate)
+ if projection_predicate.projection_ty.item_def_id == item_def_id =>
+ {
+ projection_predicate.term.ty()
+ }
+ _ => None,
+ })
+ .transpose();
+ if output.is_some() {
+ // We don't account for multiple `Future::Output = Ty` contraints.
+ return output;
  }
  }
  }
@@ -1823,8 +1830,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
  }
 
  match (
- self.get_impl_future_output_ty(exp_found.expected),
- self.get_impl_future_output_ty(exp_found.found),
+ self.get_impl_future_output_ty(exp_found.expected).map(Binder::skip_binder),
+ self.get_impl_future_output_ty(exp_found.found).map(Binder::skip_binder),
  ) {
  (Some(exp), Some(found)) if same_type_modulo_infer(exp, found) => match cause.code() {
  ObligationCauseCode::IfExpression(box IfExpressionCause { then, .. }) => {

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs

@@ -106,90 +106,47 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
  None => String::new(),
  };
 
- let (span_1, span_2, main_label, span_label, future_return_type) =
- match (sup_is_ret_type, sub_is_ret_type) {
- (None, None) => {
- let (main_label_1, span_label_1) = if ty_sup.hir_id == ty_sub.hir_id {
- (
- "this type is declared with multiple lifetimes...".to_owned(),
- "...but data with one lifetime flows into the other here".to_owned(),
- )
- } else {
- (
- "these two types are declared with different lifetimes...".to_owned(),
- format!("...but data{} flows{} here", span_label_var1, span_label_var2),
- )
- };
- (ty_sup.span, ty_sub.span, main_label_1, span_label_1, None)
- }
+ debug!(
+ "try_report_anon_anon_conflict: sub_is_ret_type={:?} sup_is_ret_type={:?}",
+ sub_is_ret_type, sup_is_ret_type
+ );
 
- (Some(ret_span), _) => {
- let sup_future = self.future_return_type(scope_def_id_sup);
- let (return_type, action) = if sup_future.is_some() {
- ("returned future", "held across an await point")
- } else {
- ("return type", "returned")
- };
+ let mut err = struct_span_err!(self.tcx().sess, span, E0623, "lifetime mismatch");
 
- (
- ty_sub.span,
- ret_span,
- format!(
- "this parameter and the {} are declared with different lifetimes...",
- return_type
- ),
- format!("...but data{} is {} here", span_label_var1, action),
- sup_future,
- )
- }
- (_, Some(ret_span)) => {
- let sub_future = self.future_return_type(scope_def_id_sub);
- let (return_type, action) = if sub_future.is_some() {
- ("returned future", "held across an await point")
- } else {
- ("return type", "returned")
- };
+ match (sup_is_ret_type, sub_is_ret_type) {
+ (ret_capture @ Some(ret_span), _) | (_, ret_capture @ Some(ret_span)) => {
+ let param_span =
+ if sup_is_ret_type == ret_capture { ty_sub.span } else { ty_sup.span };
+
+ err.span_label(
+ param_span,
+ "this parameter and the return type are declared with different lifetimes...",
+ );
+ err.span_label(ret_span, "");
+ err.span_label(span, format!("...but data{} is returned here", span_label_var1));
+ }
 
- (
+ (None, None) => {
+ if ty_sup.hir_id == ty_sub.hir_id {
+ err.span_label(ty_sup.span, "this type is declared with multiple lifetimes...");
+ err.span_label(ty_sub.span, "");
+ err.span_label(span, "...but data with one lifetime flows into the other here");
+ } else {
+ err.span_label(
  ty_sup.span,
- ret_span,
- format!(
- "this parameter and the {} are declared with different lifetimes...",
- return_type
- ),
- format!("...but data{} is {} here", span_label_var1, action),
- sub_future,
- )
+ "these two types are declared with different lifetimes...",
+ );
+ err.span_label(ty_sub.span, "");
+ err.span_label(
+ span,
+ format!("...but data{} flows{} here", span_label_var1, span_label_var2),
+ );
  }
- };
-
- let mut err = struct_span_err!(self.tcx().sess, span, E0623, "lifetime mismatch");
-
- err.span_label(span_1, main_label);
- err.span_label(span_2, String::new());
- err.span_label(span, span_label);
+ }
+ }
 
  self.suggest_adding_lifetime_params(sub, ty_sup, ty_sub, &mut err);
 
- if let Some(t) = future_return_type {
- let snip = self
- .tcx()
- .sess
- .source_map()
- .span_to_snippet(t.span)
- .ok()
- .and_then(|s| match (&t.kind, s.as_str()) {
- (rustc_hir::TyKind::Tup(&[]), "") => Some("()".to_string()),
- (_, "") => None,
- _ => Some(s),
- })
- .unwrap_or_else(|| "{unnamed_type}".to_string());
-
- err.span_label(
- t.span,
- &format!("this `async fn` implicitly returns an `impl Future<Output = {}>`", snip),
- );
- }
  err.emit();
  Some(ErrorReported)
  }