Auto merge of #87948 - JohnTitor:rollup-efmgyl8, r=JohnTitor

Rollup of 7 pull requests

Successful merges:

 - #85835 (Implement Extend<(A, B)> for (Extend<A>, Extend<B>))
 - #87671 (Warn when an escaped newline skips multiple lines)
 - #87878 (:arrow_up: rust-analyzer)
 - #87903 (Reduce verbosity of tracing output of  RUSTC_LOG)
 - #87925 (Update books)
 - #87928 (Update cargo)
 - #87942 (set the executable bit on pre-commit.sh)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Cargo.lock

@@ -356,7 +356,7 @@ dependencies = [
 
 [[package]]
 name = "cargo-platform"
-version = "0.1.1"
+version = "0.1.2"
 dependencies = [
  "serde",
 ]
@@ -1723,9 +1723,9 @@ checksum = "dc6f3ad7b9d11a0c00842ff8de1b60ee58661048eb8049ed33c73594f359d7e6"
 
 [[package]]
 name = "jobserver"
-version = "0.1.22"
+version = "0.1.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "972f5ae5d1cb9c6ae417789196c803205313edde988685da5e3aae0827b9e7fd"
+checksum = "f5ca711fd837261e14ec9e674f092cbb931d3fa1482b017ae59328ddc6f3212b"
 dependencies = [
  "libc",
 ]

compiler/rustc_driver/src/lib.rs

@@ -1287,9 +1287,6 @@ pub fn init_env_logger(env: &str) {
         .with_indent_lines(true)
         .with_ansi(color_logs)
         .with_targets(true)
-        .with_wraparound(10)
-        .with_verbose_exit(true)
-        .with_verbose_entry(true)
         .with_indent_amount(2);
     #[cfg(parallel_compiler)]
     let layer = layer.with_thread_ids(true).with_thread_names(true);

compiler/rustc_lexer/src/unescape.rs

@@ -60,13 +60,17 @@ pub enum EscapeError {
     /// After a line ending with '\', the next line contains whitespace
     /// characters that are not skipped.
     UnskippedWhitespaceWarning,
+
+    /// After a line ending with '\', multiple lines are skipped.
+    MultipleSkippedLinesWarning,
 }
 
 impl EscapeError {
     /// Returns true for actual errors, as opposed to warnings.
     pub fn is_fatal(&self) -> bool {
         match self {
             EscapeError::UnskippedWhitespaceWarning => false,
+            EscapeError::MultipleSkippedLinesWarning => false,
             _ => true,
         }
     }
@@ -315,12 +319,17 @@ where
     where
         F: FnMut(Range<usize>, Result<char, EscapeError>),
     {
-        let str = chars.as_str();
-        let first_non_space = str
+        let tail = chars.as_str();
+        let first_non_space = tail
             .bytes()
             .position(|b| b != b' ' && b != b'\t' && b != b'\n' && b != b'\r')
-            .unwrap_or(str.len());
-        let tail = &str[first_non_space..];
+            .unwrap_or(tail.len());
+        if tail[1..first_non_space].contains('\n') {
+            // The +1 accounts for the escaping slash.
+            let end = start + first_non_space + 1;
+            callback(start..end, Err(EscapeError::MultipleSkippedLinesWarning));
+        }
+        let tail = &tail[first_non_space..];
         if let Some(c) = tail.chars().nth(0) {
             // For error reporting, we would like the span to contain the character that was not
             // skipped.  The +1 is necessary to account for the leading \ that started the escape.

compiler/rustc_lexer/src/unescape/tests.rs

@@ -106,6 +106,10 @@ fn test_unescape_str_warn() {
         assert_eq!(unescaped, expected);
     }
 
+    // Check we can handle escaped newlines at the end of a file.
+    check("\\\n", &[]);
+    check("\\\n ", &[]);
+
     check(
         "\\\n \u{a0} x",
         &[
@@ -115,6 +119,7 @@ fn test_unescape_str_warn() {
             (6..7, Ok('x')),
         ],
     );
+    check("\\\n  \n  x", &[(0..7, Err(EscapeError::MultipleSkippedLinesWarning)), (7..8, Ok('x'))]);
 }
 
 #[test]

compiler/rustc_parse/src/lexer/unescape_error_reporting.rs

@@ -280,6 +280,11 @@ pub(crate) fn emit_unescape_error(
                 format!("non-ASCII whitespace symbol '{}' is not skipped", c.escape_unicode());
             handler.struct_span_warn(span, &msg).span_label(char_span, &msg).emit();
         }
+        EscapeError::MultipleSkippedLinesWarning => {
+            let msg = "multiple lines skipped by escaped newline";
+            let bottom_msg = "skipping everything up to and including this point";
+            handler.struct_span_warn(span, msg).span_label(span, bottom_msg).emit();
+        }
     }
 }
 

library/core/src/iter/traits/collect.rs

@@ -360,3 +360,61 @@ impl Extend<()> for () {
     }
     fn extend_one(&mut self, _item: ()) {}
 }
+
+#[stable(feature = "extend_for_tuple", since = "1.56.0")]
+impl<A, B, ExtendA, ExtendB> Extend<(A, B)> for (ExtendA, ExtendB)
+where
+    ExtendA: Extend<A>,
+    ExtendB: Extend<B>,
+{
+    /// Allows to `extend` a tuple of collections that also implement `Extend`.
+    ///
+    /// See also: [`Iterator::unzip`]
+    ///
+    /// # Examples
+    /// ```
+    /// let mut tuple = (vec![0], vec![1]);
+    /// tuple.extend(vec![(2, 3), (4, 5), (6, 7)]);
+    /// assert_eq!(tuple.0, vec![0, 2, 4, 6]);
+    /// assert_eq!(tuple.1, vec![1, 3, 5, 7]);
+    ///
+    /// // also allows for arbitrarily nested tuples
+    /// let mut nested_tuple = (vec![(1, -1)], vec![(2, -2)]);
+    /// nested_tuple.extend(vec![((3, -3), (4, -4)), ((5, -5), (6, -6))]);
+    ///
+    /// assert_eq!(nested_tuple.0, vec![(1, -1), (3, -3), (5, -5)]);
+    /// assert_eq!(nested_tuple.1, vec![(2, -2), (4, -4), (6, -6)]);
+    /// ```
+    fn extend<T: IntoIterator<Item = (A, B)>>(&mut self, into_iter: T) {
+        let (a, b) = self;
+        let iter = into_iter.into_iter();
+
+        fn extend<'a, A, B>(
+            a: &'a mut impl Extend<A>,
+            b: &'a mut impl Extend<B>,
+        ) -> impl FnMut((), (A, B)) + 'a {
+            move |(), (t, u)| {
+                a.extend_one(t);
+                b.extend_one(u);
+            }
+        }
+
+        let (lower_bound, _) = iter.size_hint();
+        if lower_bound > 0 {
+            a.extend_reserve(lower_bound);
+            b.extend_reserve(lower_bound);
+        }
+
+        iter.fold((), extend(a, b));
+    }
+
+    fn extend_one(&mut self, item: (A, B)) {
+        self.0.extend_one(item.0);
+        self.1.extend_one(item.1);
+    }
+
+    fn extend_reserve(&mut self, additional: usize) {
+        self.0.extend_reserve(additional);
+        self.1.extend_reserve(additional);
+    }
+}

library/core/src/iter/traits/iterator.rs

@@ -2841,6 +2841,14 @@ pub trait Iterator {
     ///
     /// assert_eq!(left, [1, 3]);
     /// assert_eq!(right, [2, 4]);
+    ///
+    /// // you can also unzip multiple nested tuples at once
+    /// let a = [(1, (2, 3)), (4, (5, 6))];
+    ///
+    /// let (x, (y, z)): (Vec<_>, (Vec<_>, Vec<_>)) = a.iter().cloned().unzip();
+    /// assert_eq!(x, [1, 4]);
+    /// assert_eq!(y, [2, 5]);
+    /// assert_eq!(z, [3, 6]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)
@@ -2849,28 +2857,9 @@ pub trait Iterator {
         FromB: Default + Extend<B>,
         Self: Sized + Iterator<Item = (A, B)>,
     {
-        fn extend<'a, A, B>(
-            ts: &'a mut impl Extend<A>,
-            us: &'a mut impl Extend<B>,
-        ) -> impl FnMut((), (A, B)) + 'a {
-            move |(), (t, u)| {
-                ts.extend_one(t);
-                us.extend_one(u);
-            }
-        }
-
-        let mut ts: FromA = Default::default();
-        let mut us: FromB = Default::default();
-
-        let (lower_bound, _) = self.size_hint();
-        if lower_bound > 0 {
-            ts.extend_reserve(lower_bound);
-            us.extend_reserve(lower_bound);
-        }
-
-        self.fold((), extend(&mut ts, &mut us));
-
-        (ts, us)
+        let mut unzipped: (FromA, FromB) = Default::default();
+        unzipped.extend(self);
+        unzipped
     }
 
     /// Creates an iterator which copies all of its elements.

src/doc/book

@@ -5,7 +5,7 @@ fn main() {
     a");
     //~^ ERROR invalid format string
     format!("{ \
-
+               \
     b");
     //~^ ERROR invalid format string
     format!(r#"{ \
@@ -38,12 +38,12 @@ fn main() {
     { \
     	\
     b \
-
+      \
     ");
     //~^^^ ERROR invalid format string
     format!(r#"
 raw  { \
-
+       \
     c"#);
     //~^^^ ERROR invalid format string
     format!(r#"

src/doc/embedded-book

@@ -19,7 +19,7 @@ error: invalid format string: expected `'}'`, found `'b'`
    |
 LL |     format!("{ \
    |              - because of this opening brace
-LL | 
+LL |                \
 LL |     b");
    |     ^ expected `}` in format string
    |

src/doc/nomicon

@@ -0,0 +1,11 @@
+// check-pass
+fn main() {
+    let s = "\
+
+             ";
+    //~^^^ WARNING multiple lines skipped by escaped newline
+    let s = "foo\
+             bar
+             ";
+    //~^^^ WARNING non-ASCII whitespace symbol '\u{a0}' is not skipped
+}

src/doc/reference

@@ -0,0 +1,21 @@
+warning: multiple lines skipped by escaped newline
+  --> $DIR/str-escape.rs:3:14
+   |
+LL |       let s = "\
+   |  ______________^
+LL | |
+LL | |              ";
+   | |_____________^ skipping everything up to and including this point
+
+warning: non-ASCII whitespace symbol '\u{a0}' is not skipped
+  --> $DIR/str-escape.rs:7:17
+   |
+LL |       let s = "foo\
+   |  _________________^
+LL | |              bar
+   | |   ^ non-ASCII whitespace symbol '\u{a0}' is not skipped
+   | |___|
+   | 
+
+warning: 2 warnings emitted
+