Rollup of 5 pull requests

src/libcore/iter/traits/iterator.rs

@@ -1472,6 +1472,11 @@ pub trait Iterator {
     /// `partition()` returns a pair, all of the elements for which it returned
     /// `true`, and all of the elements for which it returned `false`.
     ///
+    /// See also [`is_partitioned()`] and [`partition_in_place()`].
+    ///
+    /// [`is_partitioned()`]: #method.is_partitioned
+    /// [`partition_in_place()`]: #method.partition_in_place
+    ///
     /// # Examples
     ///
     /// Basic usage:
@@ -1506,6 +1511,101 @@ pub trait Iterator {
         (left, right)
     }
 
+    /// Reorder the elements of this iterator *in-place* according to the given predicate,
+    /// such that all those that return `true` precede all those that return `false`.
+    /// Returns the number of `true` elements found.
+    ///
+    /// The relative order of partitioned items is not maintained.
+    ///
+    /// See also [`is_partitioned()`] and [`partition()`].
+    ///
+    /// [`is_partitioned()`]: #method.is_partitioned
+    /// [`partition()`]: #method.partition
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(iter_partition_in_place)]
+    ///
+    /// let mut a = [1, 2, 3, 4, 5, 6, 7];
+    ///
+    /// // Partition in-place between evens and odds
+    /// let i = a.iter_mut().partition_in_place(|&n| n % 2 == 0);
+    ///
+    /// assert_eq!(i, 3);
+    /// assert!(a[..i].iter().all(|&n| n % 2 == 0)); // evens
+    /// assert!(a[i..].iter().all(|&n| n % 2 == 1)); // odds
+    /// ```
+    #[unstable(feature = "iter_partition_in_place", reason = "new API", issue = "62543")]
+    fn partition_in_place<'a, T: 'a, P>(mut self, ref mut predicate: P) -> usize
+    where
+        Self: Sized + DoubleEndedIterator<Item = &'a mut T>,
+        P: FnMut(&T) -> bool,
+    {
+        // FIXME: should we worry about the count overflowing? The only way to have more than
+        // `usize::MAX` mutable references is with ZSTs, which aren't useful to partition...
+
+        // These closure "factory" functions exist to avoid genericity in `Self`.
+
+        #[inline]
+        fn is_false<'a, T>(
+            predicate: &'a mut impl FnMut(&T) -> bool,
+            true_count: &'a mut usize,
+        ) -> impl FnMut(&&mut T) -> bool + 'a {
+            move |x| {
+                let p = predicate(&**x);
+                *true_count += p as usize;
+                !p
+            }
+        }
+
+        #[inline]
+        fn is_true<T>(
+            predicate: &mut impl FnMut(&T) -> bool
+        ) -> impl FnMut(&&mut T) -> bool + '_ {
+            move |x| predicate(&**x)
+        }
+
+        // Repeatedly find the first `false` and swap it with the last `true`.
+        let mut true_count = 0;
+        while let Some(head) = self.find(is_false(predicate, &mut true_count)) {
+            if let Some(tail) = self.rfind(is_true(predicate)) {
+                crate::mem::swap(head, tail);
+                true_count += 1;
+            } else {
+                break;
+            }
+        }
+        true_count
+    }
+
+    /// Checks if the elements of this iterator are partitioned according to the given predicate,
+    /// such that all those that return `true` precede all those that return `false`.
+    ///
+    /// See also [`partition()`] and [`partition_in_place()`].
+    ///
+    /// [`partition()`]: #method.partition
+    /// [`partition_in_place()`]: #method.partition_in_place
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(iter_is_partitioned)]
+    ///
+    /// assert!("Iterator".chars().is_partitioned(char::is_uppercase));
+    /// assert!(!"IntoIterator".chars().is_partitioned(char::is_uppercase));
+    /// ```
+    #[unstable(feature = "iter_is_partitioned", reason = "new API", issue = "62544")]
+    fn is_partitioned<P>(mut self, mut predicate: P) -> bool
+    where
+        Self: Sized,
+        P: FnMut(Self::Item) -> bool,
+    {
+        // Either all items test `true`, or the first clause stops at `false`
+        // and we check that there are no more `true` items after that.
+        self.all(&mut predicate) || !self.any(predicate)
+    }
+
     /// An iterator method that applies a function as long as it returns
     /// successfully, producing a single, final value.
     ///

src/libcore/tests/iter.rs

@@ -2460,3 +2460,39 @@ fn test_is_sorted() {
     assert!(!["c", "bb", "aaa"].iter().is_sorted());
     assert!(["c", "bb", "aaa"].iter().is_sorted_by_key(|s| s.len()));
 }
+
+#[test]
+fn test_partition() {
+    fn check(xs: &mut [i32], ref p: impl Fn(&i32) -> bool, expected: usize) {
+        let i = xs.iter_mut().partition_in_place(p);
+        assert_eq!(expected, i);
+        assert!(xs[..i].iter().all(p));
+        assert!(!xs[i..].iter().any(p));
+        assert!(xs.iter().is_partitioned(p));
+        if i == 0 || i == xs.len() {
+            assert!(xs.iter().rev().is_partitioned(p));
+        } else {
+            assert!(!xs.iter().rev().is_partitioned(p));
+        }
+    }
+
+    check(&mut [], |_| true, 0);
+    check(&mut [], |_| false, 0);
+
+    check(&mut [0], |_| true, 1);
+    check(&mut [0], |_| false, 0);
+
+    check(&mut [-1, 1], |&x| x > 0, 1);
+    check(&mut [-1, 1], |&x| x < 0, 1);
+
+    let ref mut xs = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+    check(xs, |_| true, 10);
+    check(xs, |_| false, 0);
+    check(xs, |&x| x % 2 == 0, 5); // evens
+    check(xs, |&x| x % 2 == 1, 5); // odds
+    check(xs, |&x| x % 3 == 0, 4); // multiple of 3
+    check(xs, |&x| x % 4 == 0, 3); // multiple of 4
+    check(xs, |&x| x % 5 == 0, 2); // multiple of 5
+    check(xs, |&x| x < 3, 3); // small
+    check(xs, |&x| x > 6, 3); // large
+}

src/libcore/tests/lib.rs

@@ -31,6 +31,8 @@
 #![feature(slice_partition_dedup)]
 #![feature(int_error_matching)]
 #![feature(const_fn)]
+#![feature(iter_partition_in_place)]
+#![feature(iter_is_partitioned)]
 #![warn(rust_2018_idioms)]
 
 extern crate test;

src/librustc/session/mod.rs

@@ -1303,15 +1303,15 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
     }
 
     // PGO does not work reliably with panic=unwind on Windows. Let's make it
-    // an error to combine the two for now. It always runs into an assertions
+    // a warning to combine the two for now. It always runs into an assertions
     // if LLVM is built with assertions, but without assertions it sometimes
     // does not crash and will probably generate a corrupted binary.
     if sess.opts.cg.profile_generate.enabled() &&
        sess.target.target.options.is_like_msvc &&
        sess.panic_strategy() == PanicStrategy::Unwind {
-        sess.err("Profile-guided optimization does not yet work in conjunction \
-                  with `-Cpanic=unwind` on Windows when targeting MSVC. \
-                  See https://github.com/rust-lang/rust/issues/61002 for details.");
+        sess.warn("Profile-guided optimization does not yet work in conjunction \
+                   with `-Cpanic=unwind` on Windows when targeting MSVC. \
+                   See https://github.com/rust-lang/rust/issues/61002 for details.");
     }
 }
 

src/librustc_codegen_llvm/abi.rs

@@ -34,17 +34,17 @@ trait ArgAttributeExt {
 impl ArgAttributeExt for ArgAttribute {
     fn for_each_kind<F>(&self, mut f: F) where F: FnMut(llvm::Attribute) {
         for_each_kind!(self, f,
-                       ByVal, NoAlias, NoCapture, NonNull, ReadOnly, SExt, StructRet, ZExt, InReg)
+                       NoAlias, NoCapture, NonNull, ReadOnly, SExt, StructRet, ZExt, InReg)
     }
 }
 
 pub trait ArgAttributesExt {
-    fn apply_llfn(&self, idx: AttributePlace, llfn: &Value);
-    fn apply_callsite(&self, idx: AttributePlace, callsite: &Value);
+    fn apply_llfn(&self, idx: AttributePlace, llfn: &Value, ty: Option<&Type>);
+    fn apply_callsite(&self, idx: AttributePlace, callsite: &Value, ty: Option<&Type>);
 }
 
 impl ArgAttributesExt for ArgAttributes {
-    fn apply_llfn(&self, idx: AttributePlace, llfn: &Value) {
+    fn apply_llfn(&self, idx: AttributePlace, llfn: &Value, ty: Option<&Type>) {
         let mut regular = self.regular;
         unsafe {
             let deref = self.pointee_size.bytes();
@@ -65,11 +65,14 @@ impl ArgAttributesExt for ArgAttributes {
                                                idx.as_uint(),
                                                align.bytes() as u32);
             }
+            if regular.contains(ArgAttribute::ByVal) {
+                llvm::LLVMRustAddByValAttr(llfn, idx.as_uint(), ty.unwrap());
+            }
             regular.for_each_kind(|attr| attr.apply_llfn(idx, llfn));
         }
     }
 
-    fn apply_callsite(&self, idx: AttributePlace, callsite: &Value) {
+    fn apply_callsite(&self, idx: AttributePlace, callsite: &Value, ty: Option<&Type>) {
         let mut regular = self.regular;
         unsafe {
             let deref = self.pointee_size.bytes();
@@ -90,6 +93,9 @@ impl ArgAttributesExt for ArgAttributes {
                                                        idx.as_uint(),
                                                        align.bytes() as u32);
             }
+            if regular.contains(ArgAttribute::ByVal) {
+                llvm::LLVMRustAddByValCallSiteAttr(callsite, idx.as_uint(), ty.unwrap());
+            }
             regular.for_each_kind(|attr| attr.apply_callsite(idx, callsite));
         }
     }
@@ -298,7 +304,7 @@ pub trait FnTypeLlvmExt<'tcx> {
     fn llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
     fn ptr_to_llvm_type(&self, cx: &CodegenCx<'ll, 'tcx>) -> &'ll Type;
     fn llvm_cconv(&self) -> llvm::CallConv;
-    fn apply_attrs_llfn(&self, llfn: &'ll Value);
+    fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value);
     fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value);
 }
 
@@ -384,51 +390,51 @@ impl<'tcx> FnTypeLlvmExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
         }
     }
 
-    fn apply_attrs_llfn(&self, llfn: &'ll Value) {
+    fn apply_attrs_llfn(&self, cx: &CodegenCx<'ll, 'tcx>, llfn: &'ll Value) {
         let mut i = 0;
-        let mut apply = |attrs: &ArgAttributes| {
-            attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn);
+        let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
+            attrs.apply_llfn(llvm::AttributePlace::Argument(i), llfn, ty);
             i += 1;
         };
         match self.ret.mode {
             PassMode::Direct(ref attrs) => {
-                attrs.apply_llfn(llvm::AttributePlace::ReturnValue, llfn);
+                attrs.apply_llfn(llvm::AttributePlace::ReturnValue, llfn, None);
             }
-            PassMode::Indirect(ref attrs, _) => apply(attrs),
+            PassMode::Indirect(ref attrs, _) => apply(attrs, Some(self.ret.layout.llvm_type(cx))),
             _ => {}
         }
         for arg in &self.args {
             if arg.pad.is_some() {
-                apply(&ArgAttributes::new());
+                apply(&ArgAttributes::new(), None);
             }
             match arg.mode {
                 PassMode::Ignore(_) => {}
                 PassMode::Direct(ref attrs) |
-                PassMode::Indirect(ref attrs, None) => apply(attrs),
+                PassMode::Indirect(ref attrs, None) => apply(attrs, Some(arg.layout.llvm_type(cx))),
                 PassMode::Indirect(ref attrs, Some(ref extra_attrs)) => {
-                    apply(attrs);
-                    apply(extra_attrs);
+                    apply(attrs, None);
+                    apply(extra_attrs, None);
                 }
                 PassMode::Pair(ref a, ref b) => {
-                    apply(a);
-                    apply(b);
+                    apply(a, None);
+                    apply(b, None);
                 }
-                PassMode::Cast(_) => apply(&ArgAttributes::new()),
+                PassMode::Cast(_) => apply(&ArgAttributes::new(), None),
             }
         }
     }
 
     fn apply_attrs_callsite(&self, bx: &mut Builder<'a, 'll, 'tcx>, callsite: &'ll Value) {
         let mut i = 0;
-        let mut apply = |attrs: &ArgAttributes| {
-            attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite);
+        let mut apply = |attrs: &ArgAttributes, ty: Option<&Type>| {
+            attrs.apply_callsite(llvm::AttributePlace::Argument(i), callsite, ty);
             i += 1;
         };
         match self.ret.mode {
             PassMode::Direct(ref attrs) => {
-                attrs.apply_callsite(llvm::AttributePlace::ReturnValue, callsite);
+                attrs.apply_callsite(llvm::AttributePlace::ReturnValue, callsite, None);
             }
-            PassMode::Indirect(ref attrs, _) => apply(attrs),
+            PassMode::Indirect(ref attrs, _) => apply(attrs, Some(self.ret.layout.llvm_type(bx))),
             _ => {}
         }
         if let layout::Abi::Scalar(ref scalar) = self.ret.layout.abi {
@@ -446,21 +452,21 @@ impl<'tcx> FnTypeLlvmExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
         }
         for arg in &self.args {
             if arg.pad.is_some() {
-                apply(&ArgAttributes::new());
+                apply(&ArgAttributes::new(), None);
             }
             match arg.mode {
                 PassMode::Ignore(_) => {}
                 PassMode::Direct(ref attrs) |
-                PassMode::Indirect(ref attrs, None) => apply(attrs),
+                PassMode::Indirect(ref attrs, None) => apply(attrs, Some(arg.layout.llvm_type(bx))),
                 PassMode::Indirect(ref attrs, Some(ref extra_attrs)) => {
-                    apply(attrs);
-                    apply(extra_attrs);
+                    apply(attrs, None);
+                    apply(extra_attrs, None);
                 }
                 PassMode::Pair(ref a, ref b) => {
-                    apply(a);
-                    apply(b);
+                    apply(a, None);
+                    apply(b, None);
                 }
-                PassMode::Cast(_) => apply(&ArgAttributes::new()),
+                PassMode::Cast(_) => apply(&ArgAttributes::new(), None),
             }
         }
 

src/librustc_codegen_llvm/attributes.rs

@@ -119,6 +119,29 @@ pub fn set_probestack(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
         const_cstr!("probe-stack"), const_cstr!("__rust_probestack"));
 }
 
+fn translate_obsolete_target_features(feature: &str) -> &str {
+    const LLVM9_FEATURE_CHANGES: &[(&str, &str)] = &[
+        ("+fp-only-sp", "-fp64"),
+        ("-fp-only-sp", "+fp64"),
+        ("+d16", "-d32"),
+        ("-d16", "+d32"),
+    ];
+    if llvm_util::get_major_version() >= 9 {
+        for &(old, new) in LLVM9_FEATURE_CHANGES {
+            if feature == old {
+                return new;
+            }
+        }
+    } else {
+        for &(old, new) in LLVM9_FEATURE_CHANGES {
+            if feature == new {
+                return old;
+            }
+        }
+    }
+    feature
+}
+
 pub fn llvm_target_features(sess: &Session) -> impl Iterator<Item = &str> {
     const RUSTC_SPECIFIC_FEATURES: &[&str] = &[
         "crt-static",
@@ -129,6 +152,7 @@ pub fn llvm_target_features(sess: &Session) -> impl Iterator<Item = &str> {
     sess.target.target.options.features.split(',')
         .chain(cmdline)
         .filter(|l| !l.is_empty())
+        .map(translate_obsolete_target_features)
 }
 
 pub fn apply_target_cpu_attr(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {

src/librustc_codegen_llvm/common.rs

@@ -249,6 +249,10 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         self.const_uint(self.type_i8(), i as u64)
     }
 
+    fn const_real(&self, t: &'ll Type, val: f64) -> &'ll Value {
+        unsafe { llvm::LLVMConstReal(t, val) }
+    }
+
     fn const_struct(
         &self,
         elts: &[&'ll Value],