Auto merge of #50413 - kennytm:rollup, r=kennytm

Rollup of 12 pull requests

Successful merges:

 - #50302 (Add query search order check)
 - #50320 (Fix invalid path generation in rustdoc search)
 - #50349 (Rename "show type declaration" to "show declaration")
 - #50360 (Clarify wordings of the `unstable_name_collision` lint.)
 - #50365 (Use two vectors in nearest_common_ancestor.)
 - #50393 (Allow unaligned reads in constants)
 - #50401 (Revert "Implement FromStr for PathBuf")
 - #50406 (Forbid constructing empty identifiers from concat_idents)
 - #50407 (Always inline simple BytePos and CharPos methods.)
 - #50416 (check if the token is a lifetime before parsing)
 - #50417 (Update Cargo)
 - #50421 (Fix ICE when using a..=b in a closure.)

Failed merges:

src/libcore/macros.rs

@@ -606,8 +606,8 @@ mod builtin {
     #[macro_export]
     #[cfg(dox)]
     macro_rules! concat_idents {
-        ($($e:ident),*) => ({ /* compiler built-in */ });
-        ($($e:ident,)*) => ({ /* compiler built-in */ });
+        ($($e:ident),+) => ({ /* compiler built-in */ });
+        ($($e:ident,)+) => ({ /* compiler built-in */ });
     }
 
     /// Concatenates literals into a static string slice.

src/librustc/hir/lowering.rs

@@ -3121,9 +3121,9 @@ impl<'a> LoweringContext<'a> {
             }
             // Desugar `<start>..=<end>` to `std::ops::RangeInclusive::new(<start>, <end>)`
             ExprKind::Range(Some(ref e1), Some(ref e2), RangeLimits::Closed) => {
-                // FIXME: Use head_sp directly after RangeInclusive::new() is stabilized in stage0.
+                // FIXME: Use e.span directly after RangeInclusive::new() is stabilized in stage0.
                 let span = self.allow_internal_unstable(CompilerDesugaringKind::DotFill, e.span);
-                let id = self.lower_node_id(e.id);
+                let id = self.next_id();
                 let e1 = self.lower_expr(e1);
                 let e2 = self.lower_expr(e2);
                 let ty_path = P(self.std_path(span, &["ops", "RangeInclusive"], false));

src/librustc/lint/mod.rs

@@ -507,7 +507,7 @@ pub fn struct_lint_level<'a>(sess: &'a Session,
 
         let explanation = if lint_id == LintId::of(::lint::builtin::UNSTABLE_NAME_COLLISION) {
             "once this method is added to the standard library, \
-             there will be ambiguity here, which will cause a hard error!"
+             the ambiguity may cause an error or change in behavior!"
                 .to_owned()
         } else if let Some(edition) = future_incompatible.edition {
             format!("{} in the {} edition!", STANDARD_MESSAGE, edition)

src/librustc/middle/region.rs

@@ -690,21 +690,22 @@ impl<'tcx> ScopeTree {
         // the start. So this algorithm is faster.
         let mut ma = Some(scope_a);
         let mut mb = Some(scope_b);
-        let mut seen: SmallVec<[Scope; 32]> = SmallVec::new();
+        let mut seen_a: SmallVec<[Scope; 32]> = SmallVec::new();
+        let mut seen_b: SmallVec<[Scope; 32]> = SmallVec::new();
         loop {
             if let Some(a) = ma {
-                if seen.iter().position(|s| *s == a).is_some() {
+                if seen_b.iter().position(|s| *s == a).is_some() {
                     return a;
                 }
-                seen.push(a);
+                seen_a.push(a);
                 ma = self.parent_map.get(&a).map(|s| *s);
             }
 
             if let Some(b) = mb {
-                if seen.iter().position(|s| *s == b).is_some() {
+                if seen_a.iter().position(|s| *s == b).is_some() {
                     return b;
                 }
-                seen.push(b);
+                seen_b.push(b);
                 mb = self.parent_map.get(&b).map(|s| *s);
             }
 

src/librustc_mir/hair/pattern/mod.rs

@@ -792,7 +792,7 @@ impl<'a, 'tcx> PatternContext<'a, 'tcx> {
                 ConstVal::Value(miri) => const_val_field(
                     self.tcx, self.param_env, instance,
                     variant_opt, field, miri, cv.ty,
-                ).unwrap(),
+                ).expect("field access failed"),
                 _ => bug!("{:#?} is not a valid adt", cv),
             };
             self.const_to_pat(instance, val, id, span)

src/librustc_mir/interpret/eval_context.rs

@@ -1340,9 +1340,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M
         use syntax::ast::FloatTy;
 
         let layout = self.layout_of(ty)?;
-        // do the strongest layout check of the two
-        let align = layout.align.max(ptr_align);
-        self.memory.check_align(ptr, align)?;
+        self.memory.check_align(ptr, ptr_align)?;
 
         if layout.size.bytes() == 0 {
             return Ok(Some(Value::ByVal(PrimVal::Undef)));

src/librustdoc/html/render.rs

@@ -1427,7 +1427,7 @@ impl<'a> Cache {
         }
         if let Some(ref item_name) = item.name {
             let path = self.paths.get(&item.def_id)
-                                 .map(|p| p.0.join("::").to_string())
+                                 .map(|p| p.0[..p.0.len() - 1].join("::"))
                                  .unwrap_or("std".to_owned());
             for alias in item.attrs.lists("doc")
                                    .filter(|a| a.check_name("alias"))

src/librustdoc/html/static/main.js

@@ -1996,7 +1996,7 @@
         if (e.parentNode.id === "main") {
             var otherMessage;
             if (hasClass(e, "type-decl")) {
-                otherMessage = ' Show type declaration';
+                otherMessage = ' Show declaration';
             }
             e.parentNode.insertBefore(createToggle(otherMessage), e);
             if (otherMessage && getCurrentValue('rustdoc-item-declarations') !== "false") {

src/libstd/macros.rs

@@ -450,8 +450,8 @@ pub mod builtin {
     #[unstable(feature = "concat_idents_macro", issue = "29599")]
     #[macro_export]
     macro_rules! concat_idents {
-        ($($e:ident),*) => ({ /* compiler built-in */ });
-        ($($e:ident,)*) => ({ /* compiler built-in */ });
+        ($($e:ident),+) => ({ /* compiler built-in */ });
+        ($($e:ident,)+) => ({ /* compiler built-in */ });
     }
 
     /// Concatenates literals into a static string slice.

src/libstd/path.rs

@@ -87,7 +87,6 @@ use io;
 use iter::{self, FusedIterator};
 use ops::{self, Deref};
 use rc::Rc;
-use str::FromStr;
 use sync::Arc;
 
 use ffi::{OsStr, OsString};
@@ -1441,32 +1440,6 @@ impl From<String> for PathBuf {
     }
 }
 
-/// Error returned from [`PathBuf::from_str`][`from_str`].
-///
-/// Note that parsing a path will never fail. This error is just a placeholder
-/// for implementing `FromStr` for `PathBuf`.
-///
-/// [`from_str`]: struct.PathBuf.html#method.from_str
-#[derive(Debug, Clone, PartialEq, Eq)]
-#[stable(feature = "path_from_str", since = "1.26.0")]
-pub enum ParsePathError {}
-
-#[stable(feature = "path_from_str", since = "1.26.0")]
-impl fmt::Display for ParsePathError {
-    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
-        match *self {}
-    }
-}
-
-#[stable(feature = "path_from_str", since = "1.26.0")]
-impl FromStr for PathBuf {
-    type Err = ParsePathError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(PathBuf::from(s))
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<P: AsRef<Path>> iter::FromIterator<P> for PathBuf {
     fn from_iter<I: IntoIterator<Item = P>>(iter: I) -> PathBuf {

src/libsyntax/ext/tt/macro_parser.rs

@@ -835,7 +835,13 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
         "path" => token::NtPath(panictry!(p.parse_path_common(PathStyle::Type, false))),
         "meta" => token::NtMeta(panictry!(p.parse_meta_item())),
         "vis" => token::NtVis(panictry!(p.parse_visibility(true))),
-        "lifetime" => token::NtLifetime(p.expect_lifetime().ident),
+        "lifetime" => if p.check_lifetime() {
+            token::NtLifetime(p.expect_lifetime().ident)
+        } else {
+            let token_str = pprust::token_to_string(&p.token);
+            p.fatal(&format!("expected a lifetime, found `{}`", &token_str)).emit();
+            FatalError.raise();
+        }
         // this is not supposed to happen, since it has been checked
         // when compiling the macro.
         _ => p.span_bug(sp, "invalid fragment specifier"),

src/libsyntax/parse/parser.rs

@@ -2042,7 +2042,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    fn check_lifetime(&mut self) -> bool {
+    pub fn check_lifetime(&mut self) -> bool {
         self.expected_tokens.push(TokenType::Lifetime);
         self.token.is_lifetime()
     }

src/libsyntax_ext/concat_idents.rs

@@ -31,6 +31,11 @@ pub fn expand_syntax_ext<'cx>(cx: &'cx mut ExtCtxt,
         return base::DummyResult::expr(sp);
     }
 
+    if tts.is_empty() {
+        cx.span_err(sp, "concat_idents! takes 1 or more arguments.");
+        return DummyResult::expr(sp);
+    }
+
     let mut res_str = String::new();
     for (i, e) in tts.iter().enumerate() {
         if i & 1 == 1 {

src/libsyntax_pos/lib.rs

@@ -1150,13 +1150,17 @@ pub struct CharPos(pub usize);
 // have been unsuccessful
 
 impl Pos for BytePos {
+    #[inline(always)]
     fn from_usize(n: usize) -> BytePos { BytePos(n as u32) }
+
+    #[inline(always)]
     fn to_usize(&self) -> usize { let BytePos(n) = *self; n as usize }
 }
 
 impl Add for BytePos {
     type Output = BytePos;
 
+    #[inline(always)]
     fn add(self, rhs: BytePos) -> BytePos {
         BytePos((self.to_usize() + rhs.to_usize()) as u32)
     }
@@ -1165,6 +1169,7 @@ impl Add for BytePos {
 impl Sub for BytePos {
     type Output = BytePos;
 
+    #[inline(always)]
     fn sub(self, rhs: BytePos) -> BytePos {
         BytePos((self.to_usize() - rhs.to_usize()) as u32)
     }
@@ -1183,13 +1188,17 @@ impl Decodable for BytePos {
 }
 
 impl Pos for CharPos {
+    #[inline(always)]
     fn from_usize(n: usize) -> CharPos { CharPos(n) }
+
+    #[inline(always)]
     fn to_usize(&self) -> usize { let CharPos(n) = *self; n }
 }
 
 impl Add for CharPos {
     type Output = CharPos;
 
+    #[inline(always)]
     fn add(self, rhs: CharPos) -> CharPos {
         CharPos(self.to_usize() + rhs.to_usize())
     }
@@ -1198,6 +1207,7 @@ impl Add for CharPos {
 impl Sub for CharPos {
     type Output = CharPos;
 
+    #[inline(always)]
     fn sub(self, rhs: CharPos) -> CharPos {
         CharPos(self.to_usize() - rhs.to_usize())
     }

src/test/compile-fail/macro-non-lifetime.rs

@@ -0,0 +1,20 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test for issue #50381: non-lifetime passed to :lifetime.
+
+#![feature(macro_lifetime_matcher)]
+
+macro_rules! m { ($x:lifetime) => { } }
+
+fn main() {
+    m!(a);
+    //~^ ERROR expected a lifetime, found `a`
+}

src/test/run-pass/issue-50415.rs

@@ -0,0 +1,27 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    // -------- Simplified test case --------
+
+    let _ = || 0..=1;
+
+    // -------- Original test case --------
+
+    let full_length = 1024;
+    let range = {
+        // do some stuff, omit here
+        None
+    };
+
+    let range = range.map(|(s, t)| s..=t).unwrap_or(0..=(full_length-1));
+
+    assert_eq!(range, 0..=1023);
+}

src/test/rustdoc-js/alias-2.js

@@ -8,11 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-order
+
 const QUERY = '+';
 
 const EXPECTED = {
     'others': [
-        { 'path': 'std::ops::AddAssign', 'name': 'AddAssign' },
-        { 'path': 'std::ops::Add', 'name': 'Add' },
+        { 'path': 'std::ops', 'name': 'AddAssign' },
+        { 'path': 'std::ops', 'name': 'Add' },
     ],
 };

src/test/rustdoc-js/alias.js

@@ -8,12 +8,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-order
+
 const QUERY = '[';
 
 const EXPECTED = {
     'others': [
         { 'path': 'std', 'name': 'slice' },
-        { 'path': 'std::ops::IndexMut', 'name': 'IndexMut' },
-        { 'path': 'std::ops::Index', 'name': 'Index' },
+        { 'path': 'std::ops', 'name': 'IndexMut' },
+        { 'path': 'std::ops', 'name': 'Index' },
     ],
 };

src/test/rustdoc-js/basic.js

@@ -13,8 +13,8 @@ const QUERY = 'String';
 const EXPECTED = {
     'others': [
         { 'path': 'std::string', 'name': 'String' },
-        { 'path': 'std::ffi', 'name': 'OsString' },
         { 'path': 'std::ffi', 'name': 'CString' },
+        { 'path': 'std::ffi', 'name': 'OsString' },
     ],
     'in_args': [
         { 'path': 'std::str', 'name': 'eq' },

src/test/ui/const-eval/ice-packed.rs

@@ -0,0 +1,28 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(packed)]
+pub struct Num(u64);
+
+impl Num {
+    pub const ZERO: Self = Num(0);
+}
+
+pub fn decrement(a: Num) -> Num {
+    match a {
+        Num::ZERO => Num::ZERO,
+        a => Num(a.0 - 1)
+    }
+}
+
+fn main() {
+}

src/test/ui/inference_unstable.rs

@@ -25,5 +25,5 @@ use inference_unstable_itertools::IpuItertools;
 fn main() {
     assert_eq!('x'.ipu_flatten(), 1);
     //~^ WARN a method with this name may be added to the standard library in the future
-    //~^^ WARN once this method is added to the standard library, there will be ambiguity here
+    //~^^ WARN once this method is added to the standard library, the ambiguity may cause an error
 }

src/test/ui/inference_unstable.stderr

@@ -5,7 +5,7 @@ LL |     assert_eq!('x'.ipu_flatten(), 1);
    |                    ^^^^^^^^^^^
    |
    = note: #[warn(unstable_name_collision)] on by default
-   = warning: once this method is added to the standard library, there will be ambiguity here, which will cause a hard error!
+   = warning: once this method is added to the standard library, the ambiguity may cause an error or change in behavior!
    = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
    = help: call with fully qualified syntax `inference_unstable_itertools::IpuItertools::ipu_flatten(...)` to keep using the current method
    = note: add #![feature(ipu_flatten)] to the crate attributes to enable `inference_unstable_iterator::IpuIterator::ipu_flatten`

src/test/ui/issue-50403.rs

@@ -0,0 +1,15 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(concat_idents)]
+
+fn main() {
+    let x = concat_idents!(); //~ ERROR concat_idents! takes 1 or more arguments
+}

src/test/ui/issue-50403.stderr

@@ -0,0 +1,8 @@
+error: concat_idents! takes 1 or more arguments.
+  --> $DIR/issue-50403.rs:14:13
+   |
+LL |     let x = concat_idents!(); //~ ERROR concat_idents! takes 1 or more arguments
+   |             ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+