Auto merge of #46874 - kennytm:rollup, r=kennytm

Rollup of 14 pull requests

- Successful merges: #46359, #46517, #46671, #46751, #46760, #46787, #46794, #46828, #46831, #46835, #46851, #46852, #46856, #46870
- Failed merges:

src/bootstrap/dist.rs

@@ -504,6 +504,7 @@ impl Step for DebuggerScripts {
             install(&build.src.join("src/etc/rust-windbg.cmd"), &sysroot.join("bin"),
                 0o755);
 
+            cp_debugger_script("natvis/intrinsic.natvis");
             cp_debugger_script("natvis/liballoc.natvis");
             cp_debugger_script("natvis/libcore.natvis");
         } else {

src/etc/rust-windbg.cmd

@@ -15,4 +15,4 @@ for /f "delims=" %%i in ('rustc --print=sysroot') do set rustc_sysroot=%%i
 
 set rust_etc=%rustc_sysroot%\lib\rustlib\etc
 
-windbg -c ".nvload %rust_etc%\liballoc.natvis; .nvload %rust_etc%\libcore.natvis;" %*
+windbg -c ".nvload %rust_etc%\intrinsic.natvis; .nvload %rust_etc%\liballoc.natvis; .nvload %rust_etc%\libcore.natvis;" %*

src/libcore/cell.rs

@@ -584,15 +584,14 @@ impl<T> RefCell<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(refcell_replace_swap)]
     /// use std::cell::RefCell;
     /// let cell = RefCell::new(5);
     /// let old_value = cell.replace(6);
     /// assert_eq!(old_value, 5);
     /// assert_eq!(cell, RefCell::new(6));
     /// ```
     #[inline]
-    #[unstable(feature = "refcell_replace_swap", issue="43570")]
+    #[stable(feature = "refcell_replace", since="1.24.0")]
     pub fn replace(&self, t: T) -> T {
         mem::replace(&mut *self.borrow_mut(), t)
     }
@@ -636,7 +635,6 @@ impl<T> RefCell<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(refcell_replace_swap)]
     /// use std::cell::RefCell;
     /// let c = RefCell::new(5);
     /// let d = RefCell::new(6);
@@ -645,7 +643,7 @@ impl<T> RefCell<T> {
     /// assert_eq!(d, RefCell::new(5));
     /// ```
     #[inline]
-    #[unstable(feature = "refcell_replace_swap", issue="43570")]
+    #[stable(feature = "refcell_swap", since="1.24.0")]
     pub fn swap(&self, other: &Self) {
         mem::swap(&mut *self.borrow_mut(), &mut *other.borrow_mut())
     }

src/libcore/fmt/float.rs

@@ -32,22 +32,23 @@ fn float_to_decimal_common_exact<T>(fmt: &mut Formatter, num: &T,
 // Don't inline this so callers that call both this and the above won't wind
 // up using the combined stack space of both functions in some cases.
 #[inline(never)]
-fn float_to_decimal_common_shortest<T>(fmt: &mut Formatter,
-                                       num: &T, sign: flt2dec::Sign) -> Result
+fn float_to_decimal_common_shortest<T>(fmt: &mut Formatter, num: &T,
+                                       sign: flt2dec::Sign, precision: usize) -> Result
     where T: flt2dec::DecodableFloat
 {
     unsafe {
         // enough for f32 and f64
         let mut buf: [u8; flt2dec::MAX_SIG_DIGITS] = mem::uninitialized();
         let mut parts: [flt2dec::Part; 4] = mem::uninitialized();
-        let formatted = flt2dec::to_shortest_str(flt2dec::strategy::grisu::format_shortest,
-                                                 *num, sign, 0, false, &mut buf, &mut parts);
+        let formatted = flt2dec::to_shortest_str(flt2dec::strategy::grisu::format_shortest, *num,
+                                                 sign, precision, false, &mut buf, &mut parts);
         fmt.pad_formatted_parts(&formatted)
     }
 }
 
 // Common code of floating point Debug and Display.
-fn float_to_decimal_common<T>(fmt: &mut Formatter, num: &T, negative_zero: bool) -> Result
+fn float_to_decimal_common<T>(fmt: &mut Formatter, num: &T,
+                              negative_zero: bool, min_precision: usize) -> Result
     where T: flt2dec::DecodableFloat
 {
     let force_sign = fmt.sign_plus();
@@ -61,7 +62,7 @@ fn float_to_decimal_common<T>(fmt: &mut Formatter, num: &T, negative_zero: bool)
     if let Some(precision) = fmt.precision {
         float_to_decimal_common_exact(fmt, num, sign, precision)
     } else {
-        float_to_decimal_common_shortest(fmt, num, sign)
+        float_to_decimal_common_shortest(fmt, num, sign, min_precision)
     }
 }
 
@@ -125,14 +126,14 @@ macro_rules! floating {
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Debug for $ty {
             fn fmt(&self, fmt: &mut Formatter) -> Result {
-                float_to_decimal_common(fmt, self, true)
+                float_to_decimal_common(fmt, self, true, 1)
             }
         }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Display for $ty {
             fn fmt(&self, fmt: &mut Formatter) -> Result {
-                float_to_decimal_common(fmt, self, false)
+                float_to_decimal_common(fmt, self, false, 0)
             }
         }
 

src/libcore/slice/mod.rs

@@ -400,7 +400,7 @@ impl<T> SliceExt for [T] {
         while size > 1 {
             let half = size / 2;
             let mid = base + half;
-            // mid is always in [0, size).
+            // mid is always in [0, size), that means mid is >= 0 and < size.
             // mid >= 0: by definition
             // mid < size: mid = size / 2 + size / 4 + size / 8 ...
             let cmp = f(unsafe { s.get_unchecked(mid) });

src/libcore/tests/fmt/float.rs

@@ -20,6 +20,8 @@ fn test_format_f64() {
     assert_eq!("1.23456789e3", format!("{:e}", 1234.56789f64));
     assert_eq!("1.23456789E6", format!("{:E}", 1234567.89f64));
     assert_eq!("1.23456789E3", format!("{:E}", 1234.56789f64));
+    assert_eq!("0.0", format!("{:?}", 0.0f64));
+    assert_eq!("1.01", format!("{:?}", 1.01f64));
 }
 
 #[test]
@@ -34,4 +36,6 @@ fn test_format_f32() {
     assert_eq!("1.2345679e3", format!("{:e}", 1234.56789f32));
     assert_eq!("1.2345679E6", format!("{:E}", 1234567.89f32));
     assert_eq!("1.2345679E3", format!("{:E}", 1234.56789f32));
+    assert_eq!("0.0", format!("{:?}", 0.0f32));
+    assert_eq!("1.01", format!("{:?}", 1.01f32));
 }

src/librustc/hir/print.rs

@@ -408,15 +408,16 @@ impl<'a> State<'a> {
             hir::TyTraitObject(ref bounds, ref lifetime) => {
                 let mut first = true;
                 for bound in bounds {
-                    self.nbsp()?;
                     if first {
                         first = false;
                     } else {
+                        self.nbsp()?;
                         self.word_space("+")?;
                     }
                     self.print_poly_trait_ref(bound)?;
                 }
                 if !lifetime.is_elided() {
+                    self.nbsp()?;
                     self.word_space("+")?;
                     self.print_lifetime(lifetime)?;
                 }
@@ -764,7 +765,8 @@ impl<'a> State<'a> {
                         real_bounds.push(b.clone());
                     }
                 }
-                self.print_bounds(" = ", &real_bounds[..])?;
+                self.nbsp()?;
+                self.print_bounds("=", &real_bounds[..])?;
                 self.print_where_clause(&generics.where_clause)?;
                 self.s.word(";")?;
             }
@@ -788,6 +790,7 @@ impl<'a> State<'a> {
                 comma = true;
             }
             self.s.word(">")?;
+            self.nbsp()?;
         }
         Ok(())
     }
@@ -2016,30 +2019,29 @@ impl<'a> State<'a> {
             self.s.word(prefix)?;
             let mut first = true;
             for bound in bounds {
-                self.nbsp()?;
+                if !(first && prefix.is_empty()) {
+                    self.nbsp()?;
+                }
                 if first {
                     first = false;
                 } else {
                     self.word_space("+")?;
                 }
 
-                match *bound {
-                    TraitTyParamBound(ref tref, TraitBoundModifier::None) => {
-                        self.print_poly_trait_ref(tref)
-                    }
-                    TraitTyParamBound(ref tref, TraitBoundModifier::Maybe) => {
-                        self.s.word("?")?;
-                        self.print_poly_trait_ref(tref)
+                match bound {
+                    TraitTyParamBound(tref, modifier) => {
+                        if modifier == &TraitBoundModifier::Maybe {
+                            self.s.word("?")?;
+                        }
+                        self.print_poly_trait_ref(tref)?;
                     }
-                    RegionTyParamBound(ref lt) => {
-                        self.print_lifetime(lt)
+                    RegionTyParamBound(lt) => {
+                        self.print_lifetime(lt)?;
                     }
-                }?
+                }
             }
-            Ok(())
-        } else {
-            Ok(())
         }
+        Ok(())
     }
 
     pub fn print_lifetime(&mut self, lifetime: &hir::Lifetime) -> io::Result<()> {

src/librustc/mir/visit.rs

@@ -376,7 +376,7 @@ macro_rules! make_mir_visitor {
                                                ref $($mutability)* inputs,
                                                asm: _ } => {
                         for output in & $($mutability)* outputs[..] {
-                            self.visit_place(output, PlaceContext::Store, location);
+                            self.visit_place(output, PlaceContext::AsmOutput, location);
                         }
                         for input in & $($mutability)* inputs[..] {
                             self.visit_operand(input, location);
@@ -835,6 +835,11 @@ pub enum PlaceContext<'tcx> {
     // Appears as LHS of an assignment
     Store,
 
+    // Can often be treated as a Store, but needs to be separate because
+    // ASM is allowed to read outputs as well, so a Store-AsmOutput sequence
+    // cannot be simplified the way a Store-Store can be.
+    AsmOutput,
+
     // Dest of a call
     Call,
 
@@ -910,7 +915,7 @@ impl<'tcx> PlaceContext<'tcx> {
     /// Returns true if this place context represents a use that potentially changes the value.
     pub fn is_mutating_use(&self) -> bool {
         match *self {
-            PlaceContext::Store | PlaceContext::Call |
+            PlaceContext::Store | PlaceContext::AsmOutput | PlaceContext::Call |
             PlaceContext::Borrow { kind: BorrowKind::Mut, .. } |
             PlaceContext::Projection(Mutability::Mut) |
             PlaceContext::Drop => true,
@@ -932,6 +937,7 @@ impl<'tcx> PlaceContext<'tcx> {
             PlaceContext::Projection(Mutability::Not) |
             PlaceContext::Copy | PlaceContext::Move => true,
             PlaceContext::Borrow { kind: BorrowKind::Mut, .. } | PlaceContext::Store |
+            PlaceContext::AsmOutput |
             PlaceContext::Call | PlaceContext::Projection(Mutability::Mut) |
             PlaceContext::Drop | PlaceContext::StorageLive | PlaceContext::StorageDead |
             PlaceContext::Validate => false,

src/librustc/session/config.rs

@@ -1013,6 +1013,8 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
         "set the threshold for inlining a function (default: 225)"),
     panic: Option<PanicStrategy> = (None, parse_panic_strategy,
         [TRACKED], "panic strategy to compile crate with"),
+    incremental: Option<String> = (None, parse_opt_string, [UNTRACKED],
+          "enable incremental compilation"),
 }
 
 options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
@@ -1663,7 +1665,24 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
         early_error(error_format, "Value for codegen units must be a positive nonzero integer");
     }
 
-    if cg.lto && debugging_opts.incremental.is_some() {
+    let incremental = match (&debugging_opts.incremental, &cg.incremental) {
+        (&Some(ref path1), &Some(ref path2)) => {
+            if path1 != path2 {
+                early_error(error_format,
+                    &format!("conflicting paths for `-Z incremental` and \
+                              `-C incremental` specified: {} versus {}",
+                              path1,
+                              path2));
+            } else {
+                Some(path1)
+            }
+        }
+        (&Some(ref path), &None) => Some(path),
+        (&None, &Some(ref path)) => Some(path),
+        (&None, &None) => None,
+    }.map(|m| PathBuf::from(m));
+
+    if cg.lto && incremental.is_some() {
         early_error(error_format, "can't perform LTO when compiling incrementally");
     }
 
@@ -1837,8 +1856,6 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
 
     let crate_name = matches.opt_str("crate-name");
 
-    let incremental = debugging_opts.incremental.as_ref().map(|m| PathBuf::from(m));
-
     (Options {
         crate_types,
         optimize: opt_level,
@@ -2581,6 +2598,9 @@ mod tests {
         opts.cg.save_temps = true;
         assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
 
+        opts.cg.incremental = Some(String::from("abc"));
+        assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
+
 
         // Make sure changing a [TRACKED] option changes the hash
         opts = reference.clone();

src/librustc_mir/dataflow/impls/borrows.rs

@@ -540,6 +540,10 @@ impl<'a, 'b, 'tcx> FindPlaceUses<'a, 'b, 'tcx> {
             // "deep" does validation go?
             PlaceContext::Validate => false,
 
+            // FIXME: This is here to not change behaviour from before
+            // AsmOutput existed, but it's not necessarily a pure overwrite.
+            // so it's possible this should activate the place.
+            PlaceContext::AsmOutput |
             // pure overwrites of an place do not activate it. (note
             // PlaceContext::Call is solely about dest place)
             PlaceContext::Store | PlaceContext::Call => false,

src/librustc_mir/transform/check_unsafety.rs

@@ -173,6 +173,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
                     ty::TyAdt(adt, _) => {
                         if adt.is_union() {
                             if context == PlaceContext::Store ||
+                                context == PlaceContext::AsmOutput ||
                                 context == PlaceContext::Drop
                             {
                                 let elem_ty = match elem {

src/librustc_mir/transform/promote_consts.rs

@@ -103,6 +103,7 @@ impl<'tcx> Visitor<'tcx> for TempCollector<'tcx> {
         if *temp == TempState::Undefined {
             match context {
                 PlaceContext::Store |
+                PlaceContext::AsmOutput |
                 PlaceContext::Call => {
                     *temp = TempState::Defined {
                         location,

src/librustc_mir/util/liveness.rs

@@ -273,6 +273,9 @@ impl<'tcx> Visitor<'tcx> for DefsUsesVisitor {
 
             PlaceContext::Store |
 
+            // This is potentially both a def and a use...
+            PlaceContext::AsmOutput |
+
             // We let Call define the result in both the success and
             // unwind cases. This is not really correct, however it
             // does not seem to be observable due to the way that we

src/librustc_trans/base.rs

@@ -1024,7 +1024,7 @@ fn collect_and_partition_translation_items<'a, 'tcx>(
 
     assert_symbols_are_distinct(tcx, items.iter());
 
-    let strategy = if tcx.sess.opts.debugging_opts.incremental.is_some() {
+    let strategy = if tcx.sess.opts.incremental.is_some() {
         PartitioningStrategy::PerModule
     } else {
         PartitioningStrategy::FixedUnitCount(tcx.sess.codegen_units())

src/librustc_trans/mir/analyze.rs

@@ -193,6 +193,7 @@ impl<'mir, 'a, 'tcx> Visitor<'tcx> for LocalAnalyzer<'mir, 'a, 'tcx> {
 
             PlaceContext::Inspect |
             PlaceContext::Store |
+            PlaceContext::AsmOutput |
             PlaceContext::Borrow { .. } |
             PlaceContext::Projection(..) => {
                 self.mark_as_memory(index);

src/librustc_typeck/check/mod.rs

@@ -1274,6 +1274,8 @@ fn check_impl_items_against_trait<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                             impl_id: DefId,
                                             impl_trait_ref: ty::TraitRef<'tcx>,
                                             impl_item_refs: &[hir::ImplItemRef]) {
+    let impl_span = tcx.sess.codemap().def_span(impl_span);
+
     // If the trait reference itself is erroneous (so the compilation is going
     // to fail), skip checking the items here -- the `impl_item` table in `tcx`
     // isn't populated for such impls.