Rollup of 13 pull requests

src/liballoc/boxed.rs

@@ -384,7 +384,10 @@ impl<T: ?Sized> Box<T> {
     ///
     /// unsafe {
     ///     let ptr = alloc(Layout::new::<i32>()) as *mut i32;
-    ///     *ptr = 5;
+    ///     // In general .write is required to avoid attempting to destruct
+    ///     // the (uninitialized) previous contents of `ptr`, though for this
+    ///     // simple example `*ptr = 5` would have worked as well.
+    ///     ptr.write(5);
     ///     let x = Box::from_raw(ptr);
     /// }
     /// ```

src/librustc_ast_pretty/pprust.rs

@@ -9,7 +9,7 @@ use rustc_ast::ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_ast::attr;
 use rustc_ast::ptr::P;
 use rustc_ast::token::{self, BinOpToken, DelimToken, Nonterminal, Token, TokenKind};
-use rustc_ast::tokenstream::{self, TokenStream, TokenTree};
+use rustc_ast::tokenstream::{TokenStream, TokenTree};
 use rustc_ast::util::parser::{self, AssocOp, Fixity};
 use rustc_ast::util::{classify, comments};
 use rustc_span::edition::Edition;
@@ -293,7 +293,7 @@ pub fn nonterminal_to_string(nt: &Nonterminal) -> String {
         token::NtIdent(e, is_raw) => IdentPrinter::for_ast_ident(e, is_raw).to_string(),
         token::NtLifetime(e) => e.to_string(),
         token::NtLiteral(ref e) => expr_to_string(e),
-        token::NtTT(ref tree) => tt_to_string(tree.clone()),
+        token::NtTT(ref tree) => tt_to_string(tree),
         token::NtVis(ref e) => vis_to_string(e),
     }
 }
@@ -314,11 +314,11 @@ pub fn expr_to_string(e: &ast::Expr) -> String {
     to_string(|s| s.print_expr(e))
 }
 
-pub fn tt_to_string(tt: tokenstream::TokenTree) -> String {
+pub fn tt_to_string(tt: &TokenTree) -> String {
     to_string(|s| s.print_tt(tt, false))
 }
 
-pub fn tts_to_string(tokens: TokenStream) -> String {
+pub fn tts_to_string(tokens: &TokenStream) -> String {
     to_string(|s| s.print_tts(tokens, false))
 }
 
@@ -585,7 +585,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
                 false,
                 None,
                 delim.to_token(),
-                tokens.clone(),
+                tokens,
                 true,
                 span,
             ),
@@ -594,7 +594,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
                 if let MacArgs::Eq(_, tokens) = &item.args {
                     self.space();
                     self.word_space("=");
-                    self.print_tts(tokens.clone(), true);
+                    self.print_tts(tokens, true);
                 }
             }
         }
@@ -635,9 +635,9 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
     /// appropriate macro, transcribe back into the grammar we just parsed from,
     /// and then pretty-print the resulting AST nodes (so, e.g., we print
     /// expression arguments as expressions). It can be done! I think.
-    fn print_tt(&mut self, tt: tokenstream::TokenTree, convert_dollar_crate: bool) {
+    fn print_tt(&mut self, tt: &TokenTree, convert_dollar_crate: bool) {
         match tt {
-            TokenTree::Token(ref token) => {
+            TokenTree::Token(token) => {
                 self.word(token_to_string_ext(&token, convert_dollar_crate));
                 if let token::DocComment(..) = token.kind {
                     self.hardbreak()
@@ -648,7 +648,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
                     None,
                     false,
                     None,
-                    delim,
+                    *delim,
                     tts,
                     convert_dollar_crate,
                     dspan.entire(),
@@ -657,14 +657,14 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         }
     }
 
-    fn print_tts(&mut self, tts: tokenstream::TokenStream, convert_dollar_crate: bool) {
-        let mut iter = tts.into_trees().peekable();
+    fn print_tts(&mut self, tts: &TokenStream, convert_dollar_crate: bool) {
+        let mut iter = tts.trees().peekable();
         while let Some(tt) = iter.next() {
-            let show_space =
-                if let Some(next) = iter.peek() { tt_prepend_space(next, &tt) } else { false };
-            self.print_tt(tt, convert_dollar_crate);
-            if show_space {
-                self.space();
+            self.print_tt(&tt, convert_dollar_crate);
+            if let Some(next) = iter.peek() {
+                if tt_prepend_space(next, &tt) {
+                    self.space();
+                }
             }
         }
     }
@@ -675,7 +675,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         has_bang: bool,
         ident: Option<Ident>,
         delim: DelimToken,
-        tts: TokenStream,
+        tts: &TokenStream,
         convert_dollar_crate: bool,
         span: Span,
     ) {
@@ -1253,7 +1253,7 @@ impl<'a> State<'a> {
                     has_bang,
                     Some(item.ident),
                     macro_def.body.delim(),
-                    macro_def.body.inner_tokens(),
+                    &macro_def.body.inner_tokens(),
                     true,
                     item.span,
                 );
@@ -1577,7 +1577,7 @@ impl<'a> State<'a> {
             true,
             None,
             m.args.delim(),
-            m.args.inner_tokens(),
+            &m.args.inner_tokens(),
             true,
             m.span(),
         );

src/librustc_builtin_macros/log_syntax.rs

@@ -7,7 +7,7 @@ pub fn expand_log_syntax<'cx>(
     sp: rustc_span::Span,
     tts: TokenStream,
 ) -> Box<dyn base::MacResult + 'cx> {
-    println!("{}", pprust::tts_to_string(tts));
+    println!("{}", pprust::tts_to_string(&tts));
 
     // any so that `log_syntax` can be invoked as an expression and item.
     base::DummyResult::any_valid(sp)

src/librustc_builtin_macros/source_util.rs

@@ -71,7 +71,7 @@ pub fn expand_stringify(
     tts: TokenStream,
 ) -> Box<dyn base::MacResult + 'static> {
     let sp = cx.with_def_site_ctxt(sp);
-    let s = pprust::tts_to_string(tts);
+    let s = pprust::tts_to_string(&tts);
     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&s)))
 }
 

src/librustc_codegen_ssa/back/link.rs

@@ -1597,6 +1597,9 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
         cmd.arg(format!("--dynamic-linker={}ld.so.1", prefix));
     }
 
+    // NO-OPT-OUT, OBJECT-FILES-NO, AUDIT-ORDER
+    cmd.add_eh_frame_header();
+
     // NO-OPT-OUT, OBJECT-FILES-NO
     if crt_objects_fallback {
         cmd.no_crt_objects();

src/librustc_codegen_ssa/back/linker.rs

@@ -129,6 +129,7 @@ pub trait Linker {
     fn group_start(&mut self);
     fn group_end(&mut self);
     fn linker_plugin_lto(&mut self);
+    fn add_eh_frame_header(&mut self) {}
     fn finalize(&mut self);
 }
 
@@ -615,6 +616,19 @@ impl<'a> Linker for GccLinker<'a> {
             }
         }
     }
+
+    // Add the `GNU_EH_FRAME` program header which is required to locate unwinding information.
+    // Some versions of `gcc` add it implicitly, some (e.g. `musl-gcc`) don't,
+    // so we just always add it.
+    fn add_eh_frame_header(&mut self) {
+        // The condition here is "uses ELF" basically.
+        if !self.sess.target.target.options.is_like_osx
+            && !self.sess.target.target.options.is_like_windows
+            && self.sess.target.target.target_os != "uefi"
+        {
+            self.linker_arg("--eh-frame-hdr");
+        }
+    }
 }
 
 pub struct MsvcLinker<'a> {

src/librustc_expand/mbe/macro_rules.rs

@@ -224,7 +224,7 @@ fn generic_extension<'cx>(
     let sess = cx.parse_sess;
 
     if cx.trace_macros() {
-        let msg = format!("expanding `{}! {{ {} }}`", name, pprust::tts_to_string(arg.clone()));
+        let msg = format!("expanding `{}! {{ {} }}`", name, pprust::tts_to_string(&arg));
         trace_macros_note(&mut cx.expansions, sp, msg);
     }
 
@@ -300,7 +300,7 @@ fn generic_extension<'cx>(
                 }
 
                 if cx.trace_macros() {
-                    let msg = format!("to `{}`", pprust::tts_to_string(tts.clone()));
+                    let msg = format!("to `{}`", pprust::tts_to_string(&tts));
                     trace_macros_note(&mut cx.expansions, sp, msg);
                 }
 

src/librustc_expand/proc_macro_server.rs

@@ -413,7 +413,7 @@ impl server::TokenStream for Rustc<'_> {
         )
     }
     fn to_string(&mut self, stream: &Self::TokenStream) -> String {
-        pprust::tts_to_string(stream.clone())
+        pprust::tts_to_string(stream)
     }
     fn from_token_tree(
         &mut self,

src/librustc_infer/infer/at.rs

@@ -82,7 +82,7 @@ impl<'a, 'tcx> At<'a, 'tcx> {
     where
         T: ToTrace<'tcx>,
     {
-        self.trace_exp(a_is_expected, a, b).sub(&a, &b)
+        self.trace_exp(a_is_expected, a, b).sub(a, b)
     }
 
     /// Makes `actual <: expected`. For example, if type-checking a
@@ -109,15 +109,15 @@ impl<'a, 'tcx> At<'a, 'tcx> {
     where
         T: ToTrace<'tcx>,
     {
-        self.trace_exp(a_is_expected, a, b).eq(&a, &b)
+        self.trace_exp(a_is_expected, a, b).eq(a, b)
     }
 
     /// Makes `expected <: actual`.
     pub fn eq<T>(self, expected: T, actual: T) -> InferResult<'tcx, ()>
     where
         T: ToTrace<'tcx>,
     {
-        self.trace(expected, actual).eq(&expected, &actual)
+        self.trace(expected, actual).eq(expected, actual)
     }
 
     pub fn relate<T>(self, expected: T, variance: ty::Variance, actual: T) -> InferResult<'tcx, ()>
@@ -147,7 +147,7 @@ impl<'a, 'tcx> At<'a, 'tcx> {
     where
         T: ToTrace<'tcx>,
     {
-        self.trace(expected, actual).lub(&expected, &actual)
+        self.trace(expected, actual).lub(expected, actual)
     }
 
     /// Computes the greatest-lower-bound, or mutual subtype, of two
@@ -157,7 +157,7 @@ impl<'a, 'tcx> At<'a, 'tcx> {
     where
         T: ToTrace<'tcx>,
     {
-        self.trace(expected, actual).glb(&expected, &actual)
+        self.trace(expected, actual).glb(expected, actual)
     }
 
     /// Sets the "trace" values that will be used for
@@ -186,7 +186,7 @@ impl<'a, 'tcx> At<'a, 'tcx> {
 impl<'a, 'tcx> Trace<'a, 'tcx> {
     /// Makes `a <: b` where `a` may or may not be expected (if
     /// `a_is_expected` is true, then `a` is expected).
-    pub fn sub<T>(self, a: &T, b: &T) -> InferResult<'tcx, ()>
+    pub fn sub<T>(self, a: T, b: T) -> InferResult<'tcx, ()>
     where
         T: Relate<'tcx>,
     {
@@ -203,7 +203,7 @@ impl<'a, 'tcx> Trace<'a, 'tcx> {
 
     /// Makes `a == b`; the expectation is set by the call to
     /// `trace()`.
-    pub fn eq<T>(self, a: &T, b: &T) -> InferResult<'tcx, ()>
+    pub fn eq<T>(self, a: T, b: T) -> InferResult<'tcx, ()>
     where
         T: Relate<'tcx>,
     {
@@ -218,7 +218,7 @@ impl<'a, 'tcx> Trace<'a, 'tcx> {
         })
     }
 
-    pub fn lub<T>(self, a: &T, b: &T) -> InferResult<'tcx, T>
+    pub fn lub<T>(self, a: T, b: T) -> InferResult<'tcx, T>
     where
         T: Relate<'tcx>,
     {
@@ -233,7 +233,7 @@ impl<'a, 'tcx> Trace<'a, 'tcx> {
         })
     }
 
-    pub fn glb<T>(self, a: &T, b: &T) -> InferResult<'tcx, T>
+    pub fn glb<T>(self, a: T, b: T) -> InferResult<'tcx, T>
     where
         T: Relate<'tcx>,
     {

src/librustc_infer/infer/canonical/query_response.rs

@@ -271,7 +271,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
                         },
                         ty::Variance::Invariant,
                     )
-                    .relate(&v1, &v2)?;
+                    .relate(v1, v2)?;
                 }
 
                 (GenericArgKind::Const(v1), GenericArgKind::Const(v2)) => {
@@ -285,7 +285,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
                         },
                         ty::Variance::Invariant,
                     )
-                    .relate(&v1, &v2)?;
+                    .relate(v1, v2)?;
                 }
 
                 _ => {
@@ -302,7 +302,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
                 // Screen out `'a: 'a` cases -- we skip the binder here but
                 // only compare the inner values to one another, so they are still at
                 // consistent binding levels.
-                let &ty::OutlivesPredicate(k1, r2) = r_c.skip_binder();
+                let ty::OutlivesPredicate(k1, r2) = r_c.skip_binder();
                 if k1 != r2.into() { Some(r_c) } else { None }
             }),
         );
@@ -526,7 +526,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
     ) -> impl Iterator<Item = PredicateObligation<'tcx>> + 'a + Captures<'tcx> {
         unsubstituted_region_constraints.iter().map(move |constraint| {
             let constraint = substitute_value(self.tcx, result_subst, constraint);
-            let &ty::OutlivesPredicate(k1, r2) = constraint.skip_binder(); // restored below
+            let ty::OutlivesPredicate(k1, r2) = constraint.skip_binder(); // restored below
 
             Obligation::new(
                 cause.clone(),

src/librustc_infer/infer/combine.rs

@@ -318,10 +318,10 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
         // to associate causes/spans with each of the relations in
         // the stack to get this right.
         match dir {
-            EqTo => self.equate(a_is_expected).relate(&a_ty, &b_ty),
-            SubtypeOf => self.sub(a_is_expected).relate(&a_ty, &b_ty),
+            EqTo => self.equate(a_is_expected).relate(a_ty, b_ty),
+            SubtypeOf => self.sub(a_is_expected).relate(a_ty, b_ty),
             SupertypeOf => {
-                self.sub(a_is_expected).relate_with_variance(ty::Contravariant, &a_ty, &b_ty)
+                self.sub(a_is_expected).relate_with_variance(ty::Contravariant, a_ty, b_ty)
             }
         }?;
 
@@ -379,7 +379,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
             param_env: self.param_env,
         };
 
-        let ty = match generalize.relate(&ty, &ty) {
+        let ty = match generalize.relate(ty, ty) {
             Ok(ty) => ty,
             Err(e) => {
                 debug!("generalize: failure {:?}", e);
@@ -490,8 +490,8 @@ impl TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
 
     fn binders<T>(
         &mut self,
-        a: &ty::Binder<T>,
-        b: &ty::Binder<T>,
+        a: ty::Binder<T>,
+        b: ty::Binder<T>,
     ) -> RelateResult<'tcx, ty::Binder<T>>
     where
         T: Relate<'tcx>,
@@ -519,8 +519,8 @@ impl TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
     fn relate_with_variance<T: Relate<'tcx>>(
         &mut self,
         variance: ty::Variance,
-        a: &T,
-        b: &T,
+        a: T,
+        b: T,
     ) -> RelateResult<'tcx, T> {
         let old_ambient_variance = self.ambient_variance;
         self.ambient_variance = self.ambient_variance.xform(variance);
@@ -552,7 +552,7 @@ impl TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                     match probe {
                         TypeVariableValue::Known { value: u } => {
                             debug!("generalize: known value {:?}", u);
-                            self.relate(&u, &u)
+                            self.relate(u, u)
                         }
                         TypeVariableValue::Unknown { universe } => {
                             match self.ambient_variance {
@@ -655,7 +655,7 @@ impl TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                 let variable_table = &mut inner.const_unification_table();
                 let var_value = variable_table.probe_value(vid);
                 match var_value.val {
-                    ConstVariableValue::Known { value: u } => self.relate(&u, &u),
+                    ConstVariableValue::Known { value: u } => self.relate(u, u),
                     ConstVariableValue::Unknown { universe } => {
                         if self.for_universe.can_name(universe) {
                             Ok(c)