Auto merge of #62485 - Centril:rollup-gg3it1u, r=Centril

Rollup of 5 pull requests

Successful merges:

 - #62356 (Implement Option::contains and Result::contains)
 - #62462 (Document `while` keyword)
 - #62472 (Normalize use of backticks in compiler messages p2)
 - #62477 (Re-add bootstrap attribute to libunwind for llvm-libunwind feature)
 - #62478 (normalize use of backticks for compiler messages in librustc_codegen)

Failed merges:

r? @ghost

src/libcore/option.rs

@@ -208,6 +208,32 @@ impl<T> Option<T> {
         !self.is_some()
     }
 
+    /// Returns `true` if the option is a [`Some`] value containing the given value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(option_result_contains)]
+    ///
+    /// let x: Option<u32> = Some(2);
+    /// assert_eq!(x.contains(&2), true);
+    ///
+    /// let x: Option<u32> = Some(3);
+    /// assert_eq!(x.contains(&2), false);
+    ///
+    /// let x: Option<u32> = None;
+    /// assert_eq!(x.contains(&2), false);
+    /// ```
+    #[must_use]
+    #[inline]
+    #[unstable(feature = "option_result_contains", issue = "62358")]
+    pub fn contains<U>(&self, x: &U) -> bool where U: PartialEq<T> {
+        match self {
+            Some(y) => x == y,
+            None => false,
+        }
+    }
+
     /////////////////////////////////////////////////////////////////////////
     // Adapter for working with references
     /////////////////////////////////////////////////////////////////////////

src/libcore/result.rs

@@ -309,6 +309,58 @@ impl<T, E> Result<T, E> {
         !self.is_ok()
     }
 
+    /// Returns `true` if the result is an [`Ok`] value containing the given value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(option_result_contains)]
+    ///
+    /// let x: Result<u32, &str> = Ok(2);
+    /// assert_eq!(x.contains(&2), true);
+    ///
+    /// let x: Result<u32, &str> = Ok(3);
+    /// assert_eq!(x.contains(&2), false);
+    ///
+    /// let x: Result<u32, &str> = Err("Some error message");
+    /// assert_eq!(x.contains(&2), false);
+    /// ```
+    #[must_use]
+    #[inline]
+    #[unstable(feature = "option_result_contains", issue = "62358")]
+    pub fn contains<U>(&self, x: &U) -> bool where U: PartialEq<T> {
+        match self {
+            Ok(y) => x == y,
+            Err(_) => false
+        }
+    }
+
+    /// Returns `true` if the result is an [`Err`] value containing the given value.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(result_contains_err)]
+    ///
+    /// let x: Result<u32, &str> = Ok(2);
+    /// assert_eq!(x.contains_err(&"Some error message"), false);
+    ///
+    /// let x: Result<u32, &str> = Err("Some error message");
+    /// assert_eq!(x.contains_err(&"Some error message"), true);
+    ///
+    /// let x: Result<u32, &str> = Err("Some other error message");
+    /// assert_eq!(x.contains_err(&"Some error message"), false);
+    /// ```
+    #[must_use]
+    #[inline]
+    #[unstable(feature = "result_contains_err", issue = "62358")]
+    pub fn contains_err<F>(&self, f: &F) -> bool where F: PartialEq<E> {
+        match self {
+            Ok(_) => false,
+            Err(e) => f == e
+        }
+    }
+
     /////////////////////////////////////////////////////////////////////////
     // Adapter for each variant
     /////////////////////////////////////////////////////////////////////////

src/librustc_codegen_llvm/asm.rs

@@ -146,7 +146,7 @@ fn inline_asm_call(
     unsafe {
         // Ask LLVM to verify that the constraints are well-formed.
         let constraints_ok = llvm::LLVMRustInlineAsmVerify(fty, cons.as_ptr());
-        debug!("Constraint verification result: {:?}", constraints_ok);
+        debug!("constraint verification result: {:?}", constraints_ok);
         if constraints_ok {
             let v = llvm::LLVMRustInlineAsm(
                 fty,

src/librustc_codegen_llvm/builder.rs

@@ -215,7 +215,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         funclet: Option<&Funclet<'ll>>,
     ) -> &'ll Value {
 
-        debug!("Invoke {:?} with args ({:?})",
+        debug!("invoke {:?} with args ({:?})",
                llfn,
                args);
 
@@ -1035,7 +1035,7 @@ impl BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         funclet: Option<&Funclet<'ll>>,
     ) -> &'ll Value {
 
-        debug!("Call {:?} with args ({:?})",
+        debug!("call {:?} with args ({:?})",
                llfn,
                args);
 
@@ -1238,7 +1238,7 @@ impl Builder<'a, 'll, 'tcx> {
         if dest_ptr_ty == stored_ptr_ty {
             ptr
         } else {
-            debug!("Type mismatch in store. \
+            debug!("type mismatch in store. \
                     Expected {:?}, got {:?}; inserting bitcast",
                    dest_ptr_ty, stored_ptr_ty);
             self.bitcast(ptr, stored_ptr_ty)
@@ -1274,7 +1274,7 @@ impl Builder<'a, 'll, 'tcx> {
             .map(|(i, (expected_ty, &actual_val))| {
                 let actual_ty = self.val_ty(actual_val);
                 if expected_ty != actual_ty {
-                    debug!("Type mismatch in function call of {:?}. \
+                    debug!("type mismatch in function call of {:?}. \
                             Expected {:?} for param {}, got {:?}; injecting bitcast",
                            llfn, expected_ty, i, actual_ty);
                     self.bitcast(actual_val, expected_ty)

src/librustc_codegen_ssa/base.rs

@@ -433,7 +433,7 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'
         if cx.get_defined_value("main").is_some() {
             // FIXME: We should be smart and show a better diagnostic here.
             cx.sess().struct_span_err(sp, "entry symbol `main` defined multiple times")
-                     .help("did you use #[no_mangle] on `fn main`? Use #[start] instead")
+                     .help("did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead")
                      .emit();
             cx.sess().abort_if_errors();
             bug!();

src/librustc_codegen_ssa/mir/place.rs

@@ -138,7 +138,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         //   * packed struct - there is no alignment padding
         match field.ty.sty {
             _ if self.llextra.is_none() => {
-                debug!("Unsized field `{}`, of `{:?}` has no metadata for adjustment",
+                debug!("unsized field `{}`, of `{:?}` has no metadata for adjustment",
                     ix, self.llval);
                 return simple();
             }

src/librustc_codegen_utils/link.rs

@@ -57,7 +57,7 @@ pub fn find_crate_name(sess: Option<&Session>,
         if let Some(ref s) = sess.opts.crate_name {
             if let Some((attr, name)) = attr_crate_name {
                 if name.as_str() != *s {
-                    let msg = format!("--crate-name and #[crate_name] are \
+                    let msg = format!("`--crate-name` and `#[crate_name]` are \
                                        required to match, but `{}` != `{}`",
                                       s, name);
                     sess.span_err(attr.span, &msg);

src/librustc_typeck/check/coercion.rs

@@ -459,7 +459,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         let (unsize_did, coerce_unsized_did) = if let (Some(u), Some(cu)) = traits {
             (u, cu)
         } else {
-            debug!("Missing Unsize or CoerceUnsized traits");
+            debug!("missing Unsize or CoerceUnsized traits");
             return Err(TypeError::Mismatch);
         };
 

src/librustc_typeck/check/generator_interior.rs

@@ -130,7 +130,7 @@ pub fn resolve_interior<'a, 'tcx>(
     // if a Sync generator contains an &'α T, we need to check whether &'α T: Sync),
     // so knowledge of the exact relationships between them isn't particularly important.
 
-    debug!("Types in generator {:?}, span = {:?}", type_list, body.value.span);
+    debug!("types in generator {:?}, span = {:?}", type_list, body.value.span);
 
     // Replace all regions inside the generator interior with late bound regions
     // Note that each region slot in the types gets a new fresh late bound region,
@@ -144,7 +144,7 @@ pub fn resolve_interior<'a, 'tcx>(
 
     let witness = fcx.tcx.mk_generator_witness(ty::Binder::bind(type_list));
 
-    debug!("Types in generator after region replacement {:?}, span = {:?}",
+    debug!("types in generator after region replacement {:?}, span = {:?}",
             witness, body.value.span);
 
     // Unify the type variable inside the generator with the new witness

src/librustc_typeck/check/method/probe.rs

@@ -1230,7 +1230,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         if nightly_options::is_nightly_build() {
             for (candidate, feature) in unstable_candidates {
                 diag.help(&format!(
-                    "add #![feature({})] to the crate attributes to enable `{}`",
+                    "add `#![feature({})]` to the crate attributes to enable `{}`",
                     feature,
                     self.tcx.def_path_str(candidate.item.def_id),
                 ));
@@ -1432,7 +1432,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     /// candidate method where the method name may have been misspelt. Similarly to other
     /// Levenshtein based suggestions, we provide at most one such suggestion.
     fn probe_for_lev_candidate(&mut self) -> Result<Option<ty::AssocItem>, MethodError<'tcx>> {
-        debug!("Probing for method names similar to {:?}",
+        debug!("probing for method names similar to {:?}",
                self.method_name);
 
         let steps = self.steps.clone();

src/librustc_typeck/check/mod.rs

@@ -983,7 +983,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
         };
         self.assign(local.span, local.hir_id, local_ty);
 
-        debug!("Local variable {:?} is assigned type {}",
+        debug!("local variable {:?} is assigned type {}",
                local.pat,
                self.fcx.ty_to_string(
                    self.fcx.locals.borrow().get(&local.hir_id).unwrap().clone().decl_ty));
@@ -1000,7 +1000,7 @@ impl<'a, 'tcx> Visitor<'tcx> for GatherLocalsVisitor<'a, 'tcx> {
                                                traits::VariableType(p.hir_id));
             }
 
-            debug!("Pattern binding {} is assigned to {} with type {:?}",
+            debug!("pattern binding {} is assigned to {} with type {:?}",
                    ident,
                    self.fcx.ty_to_string(
                        self.fcx.locals.borrow().get(&p.hir_id).unwrap().clone().decl_ty),
@@ -4462,7 +4462,7 @@ pub fn check_bounds_are_used<'tcx>(tcx: TyCtxt<'tcx>, generics: &ty::Generics, t
 
     for leaf_ty in ty.walk() {
         if let ty::Param(ty::ParamTy { index, .. }) = leaf_ty.sty {
-            debug!("Found use of ty param num {}", index);
+            debug!("found use of ty param num {}", index);
             types_used[index as usize - own_counts.lifetimes] = true;
         } else if let ty::Error = leaf_ty.sty {
             // If there is already another error, do not emit

src/librustc_typeck/check/regionck.rs

@@ -799,7 +799,7 @@ impl<'a, 'tcx> RegionCtxt<'a, 'tcx> {
         debug!("callee_region={:?}", callee_region);
 
         for arg_expr in arg_exprs {
-            debug!("Argument: {:?}", arg_expr);
+            debug!("argument: {:?}", arg_expr);
 
             // ensure that any regions appearing in the argument type are
             // valid for at least the lifetime of the function:

src/librustc_typeck/check/writeback.rs

@@ -646,7 +646,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
         let n_ty = self.fcx.node_ty(hir_id);
         let n_ty = self.resolve(&n_ty, &span);
         self.write_ty_to_tables(hir_id, n_ty);
-        debug!("Node {:?} has type {:?}", hir_id, n_ty);
+        debug!("node {:?} has type {:?}", hir_id, n_ty);
 
         // Resolve any substitutions
         if let Some(substs) = self.fcx.tables.borrow().node_substs_opt(hir_id) {
@@ -665,13 +665,13 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
             .remove(hir_id);
         match adjustment {
             None => {
-                debug!("No adjustments for node {:?}", hir_id);
+                debug!("no adjustments for node {:?}", hir_id);
             }
 
             Some(adjustment) => {
                 let resolved_adjustment = self.resolve(&adjustment, &span);
                 debug!(
-                    "Adjustments for node {:?}: {:?}",
+                    "adjustments for node {:?}: {:?}",
                     hir_id, resolved_adjustment
                 );
                 self.tables
@@ -689,7 +689,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
             .remove(hir_id);
         match adjustment {
             None => {
-                debug!("No pat_adjustments for node {:?}", hir_id);
+                debug!("no pat_adjustments for node {:?}", hir_id);
             }
 
             Some(adjustment) => {

src/librustc_typeck/collect.rs

@@ -2256,7 +2256,7 @@ fn compute_sig_of_foreign_fn_decl<'tcx>(
                            tcx.hir().hir_to_pretty_string(ast_ty.hir_id)
                        ),
                    )
-                   .help("add #![feature(simd_ffi)] to the crate attributes to enable")
+                   .help("add `#![feature(simd_ffi)]` to the crate attributes to enable")
                    .emit();
             }
         };
@@ -2479,7 +2479,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
             }
         } else if attr.check_name(sym::target_feature) {
             if tcx.fn_sig(id).unsafety() == Unsafety::Normal {
-                let msg = "#[target_feature(..)] can only be applied to `unsafe` functions";
+                let msg = "`#[target_feature(..)]` can only be applied to `unsafe` functions";
                 tcx.sess.struct_span_err(attr.span, msg)
                     .span_label(attr.span, "can only be applied to `unsafe` functions")
                     .span_label(tcx.def_span(id), "not an `unsafe` function")
@@ -2593,8 +2593,8 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
             if let Some(span) = inline_span {
                 tcx.sess.span_err(
                     span,
-                    "cannot use #[inline(always)] with \
-                     #[target_feature]",
+                    "cannot use `#[inline(always)]` with \
+                     `#[target_feature]`",
                 );
             }
         }

src/librustc_typeck/error_codes.rs

@@ -4848,6 +4848,6 @@ register_diagnostics! {
     E0641, // cannot cast to/from a pointer with an unknown kind
     E0645, // trait aliases not finished
     E0719, // duplicate values for associated type binding
-    E0722, // Malformed #[optimize] attribute
+    E0722, // Malformed `#[optimize]` attribute
     E0724, // `#[ffi_returns_twice]` is only allowed in foreign functions
 }

src/librustc_typeck/variance/solve.rs

@@ -64,7 +64,7 @@ impl<'a, 'tcx> SolveContext<'a, 'tcx> {
                 let old_value = self.solutions[inferred];
                 let new_value = glb(variance, old_value);
                 if old_value != new_value {
-                    debug!("Updating inferred {} \
+                    debug!("updating inferred {} \
                             from {:?} to {:?} due to {:?}",
                            inferred,
                            old_value,