Rollup merge of rust-lang#58743 - varkor:bulk-needstest-1, r=alexcric…

…hton

Add tests for several E-needstest issues

This PR adds a number of tests for various `E-needstest` errors. These tend to have been left open for a long time and seem unlikely to be closed otherwise.

Closes rust-lang#10876.
Closes rust-lang#26448.
Closes rust-lang#26577.
Closes rust-lang#26619.
Closes rust-lang#27054.
Closes rust-lang#44127.
Closes rust-lang#44255.
Closes rust-lang#55731.
Closes rust-lang#57781.

src/test/ui/block-expression-remove-semicolon.rs

@@ -0,0 +1,10 @@
+fn foo() -> i32 {
+   0
+}
+
+fn main() {
+    let x: i32 = {
+        //~^ ERROR mismatched types
+        foo(); //~ HELP consider removing this semicolon
+    };
+}

src/test/ui/block-expression-remove-semicolon.stderr

@@ -0,0 +1,17 @@
+error[E0308]: mismatched types
+  --> $DIR/block-expression-remove-semicolon.rs:6:18
+   |
+LL |       let x: i32 = {
+   |  __________________^
+LL | |
+LL | |         foo();
+   | |              - help: consider removing this semicolon
+LL | |     };
+   | |_____^ expected i32, found ()
+   |
+   = note: expected type `i32`
+              found type `()`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/borrowck/issue-10876.rs

@@ -0,0 +1,19 @@
+// run-pass
+
+#![feature(nll)]
+
+enum Nat {
+    S(Box<Nat>),
+    Z
+}
+fn test(x: &mut Nat) {
+    let mut p = &mut *x;
+    loop {
+        match p {
+            &mut Nat::Z => break,
+            &mut Nat::S(ref mut n) => p = &mut *n
+        }
+    }
+}
+
+fn main() {}

src/test/ui/issues/issue-26448-1.rs

@@ -0,0 +1,13 @@
+// run-pass
+
+pub trait Foo<T> {
+    fn foo(self) -> T;
+}
+
+impl<'a, T> Foo<T> for &'a str where &'a str: Into<T> {
+    fn foo(self) -> T {
+        panic!();
+    }
+}
+
+fn main() {}

src/test/ui/issues/issue-26448-2.rs

@@ -0,0 +1,21 @@
+// run-pass
+
+pub struct Bar<T> {
+    items: Vec<&'static str>,
+    inner: T,
+}
+
+pub trait IntoBar<T> {
+    fn into_bar(self) -> Bar<T>;
+}
+
+impl<'a, T> IntoBar<T> for &'a str where &'a str: Into<T> {
+    fn into_bar(self) -> Bar<T> {
+        Bar {
+            items: Vec::new(),
+            inner: self.into(),
+        }
+    }
+}
+
+fn main() {}

src/test/ui/issues/issue-26448-3.rs

@@ -0,0 +1,25 @@
+// run-pass
+
+pub struct Item {
+    _inner: &'static str,
+}
+
+pub struct Bar<T> {
+    items: Vec<Item>,
+    inner: T,
+}
+
+pub trait IntoBar<T> {
+    fn into_bar(self) -> Bar<T>;
+}
+
+impl<'a, T> IntoBar<T> for &'a str where &'a str: Into<T> {
+    fn into_bar(self) -> Bar<T> {
+        Bar {
+            items: Vec::new(),
+            inner: self.into(),
+        }
+    }
+}
+
+fn main() {}

src/test/ui/issues/issue-26619.nll.stderr

@@ -0,0 +1,11 @@
+error[E0515]: cannot return value referencing function parameter
+  --> $DIR/issue-26619.rs:7:76
+   |
+LL |         for s in vec!["1|2".to_string()].into_iter().filter_map(|ref line| self.make_entry(line)) {
+   |                                                                  --------  ^^^^^^^^^^^^^^^^^^^^^ returns a value referencing data owned by the current function
+   |                                                                  |
+   |                                                                  function parameter borrowed here
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0515`.

src/test/ui/issues/issue-26619.rs

@@ -0,0 +1,24 @@
+#![feature(slice_patterns)]
+
+pub struct History<'a> { pub _s: &'a str }
+
+impl<'a> History<'a> {
+    pub fn get_page(&self) {
+        for s in vec!["1|2".to_string()].into_iter().filter_map(|ref line| self.make_entry(line)) {
+            //~^ ERROR borrowed value does not live long enough
+            println!("{:?}", s);
+        }
+    }
+
+    fn make_entry(&self, s: &'a String) -> Option<&str> {
+        let parts: Vec<_> = s.split('|').collect();
+        println!("{:?} -> {:?}", s, parts);
+
+        if let [commit, ..] = &parts[..] { Some(commit) } else { None }
+    }
+}
+
+fn main() {
+    let h = History{ _s: "" };
+    h.get_page();
+}

src/test/ui/issues/issue-26619.stderr

@@ -0,0 +1,12 @@
+error[E0597]: borrowed value does not live long enough
+  --> $DIR/issue-26619.rs:7:66
+   |
+LL |         for s in vec!["1|2".to_string()].into_iter().filter_map(|ref line| self.make_entry(line)) {
+   |                                                                  ^^^^^^^^                      -- temporary value needs to live until here
+   |                                                                  |                             |
+   |                                                                  |                             temporary value dropped here while still borrowed
+   |                                                                  temporary value does not live long enough
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0597`.

src/test/ui/issues/issue-44127.rs

@@ -0,0 +1,17 @@
+// run-pass
+
+#![feature(decl_macro)]
+
+pub struct Foo {
+    bar: u32,
+}
+pub macro pattern($a:pat) {
+    Foo { bar: $a }
+}
+
+fn main() {
+    match (Foo { bar: 3 }) {
+        pattern!(3) => println!("Test OK"),
+        _ => unreachable!(),
+    }
+}

src/test/ui/issues/issue-44255.rs

@@ -0,0 +1,29 @@
+// run-pass
+
+use std::marker::PhantomData;
+
+fn main() {
+    let _arr = [1; <Multiply<Five, Five>>::VAL];
+}
+
+trait TypeVal<T> {
+    const VAL: T;
+}
+
+struct Five;
+
+impl TypeVal<usize> for Five {
+    const VAL: usize = 5;
+}
+
+struct Multiply<N, M> {
+    _n: PhantomData<N>,
+    _m: PhantomData<M>,
+}
+
+impl<N, M> TypeVal<usize> for Multiply<N, M>
+    where N: TypeVal<usize>,
+          M: TypeVal<usize>,
+{
+    const VAL: usize = N::VAL * M::VAL;
+}

src/test/ui/issues/issue-46101.rs

@@ -0,0 +1,4 @@
+#![feature(use_extern_macros)]
+trait Foo {}
+#[derive(Foo::Anything)] //~ ERROR failed to resolve: partially resolved path in a derive macro
+struct S;

src/test/ui/issues/issue-46101.stderr

@@ -0,0 +1,14 @@
+error[E0433]: failed to resolve: partially resolved path in a derive macro
+  --> $DIR/issue-46101.rs:3:10
+   |
+LL | #[derive(Foo::Anything)]
+   |          ^^^^^^^^^^^^^ partially resolved path in a derive macro
+
+error[E0601]: `main` function not found in crate `issue_46101`
+   |
+   = note: consider adding a `main` function to `$DIR/issue-46101.rs`
+
+error: aborting due to 2 previous errors
+
+Some errors occurred: E0433, E0601.
+For more information about an error, try `rustc --explain E0433`.

src/test/ui/issues/issue-55731.rs

@@ -0,0 +1,52 @@
+use std::marker::PhantomData;
+
+trait DistributedIterator {
+    fn reduce(self)
+    where
+        Self: Sized,
+    {
+        unreachable!()
+    }
+}
+
+trait DistributedIteratorMulti<Source> {
+    type Item;
+}
+
+struct Connect<I>(PhantomData<fn(I)>);
+impl<I: for<'a> DistributedIteratorMulti<&'a ()>> DistributedIterator for Connect<I> where {}
+
+struct Cloned<Source>(PhantomData<fn(Source)>);
+impl<'a, Source> DistributedIteratorMulti<&'a Source> for Cloned<&'a Source> {
+    type Item = ();
+}
+
+struct Map<I, F> {
+    i: I,
+    f: F,
+}
+impl<I: DistributedIteratorMulti<Source>, F, Source> DistributedIteratorMulti<Source> for Map<I, F>
+where
+    F: A<<I as DistributedIteratorMulti<Source>>::Item>,
+{
+    type Item = ();
+}
+
+trait A<B> {}
+
+struct X;
+impl A<()> for X {}
+
+fn multi<I>(_reducer: I)
+where
+    I: for<'a> DistributedIteratorMulti<&'a ()>,
+{
+    DistributedIterator::reduce(Connect::<I>(PhantomData))
+}
+
+fn main() {
+    multi(Map { //~ ERROR implementation of `DistributedIteratorMulti` is not general enough
+        i: Cloned(PhantomData),
+        f: X,
+    });
+}

src/test/ui/issues/issue-55731.stderr

@@ -0,0 +1,11 @@
+error: implementation of `DistributedIteratorMulti` is not general enough
+  --> $DIR/issue-55731.rs:48:5
+   |
+LL |     multi(Map {
+   |     ^^^^^
+   |
+   = note: `DistributedIteratorMulti<&'0 ()>` would have to be implemented for the type `Cloned<&()>`, for any lifetime `'0`
+   = note: but `DistributedIteratorMulti<&'1 ()>` is actually implemented for the type `Cloned<&'1 ()>`, for some specific lifetime `'1`
+
+error: aborting due to previous error
+

src/test/ui/issues/issue-57781.rs

@@ -0,0 +1,20 @@
+// run-pass
+
+use std::cell::UnsafeCell;
+use std::collections::HashMap;
+
+struct OnceCell<T> {
+    _value: UnsafeCell<Option<T>>,
+}
+
+impl<T> OnceCell<T> {
+    const INIT: OnceCell<T> = OnceCell {
+        _value: UnsafeCell::new(None),
+    };
+}
+
+pub fn crash<K, T>() {
+    let _ = OnceCell::<HashMap<K, T>>::INIT;
+}
+
+fn main() {}

src/test/ui/primitive-binop-lhs-mut.rs

@@ -0,0 +1,6 @@
+// run-pass
+
+fn main() {
+    let x = Box::new(0);
+    assert_eq!(0, *x + { drop(x); let _ = Box::new(main); 0 });
+}