Rework the suspicious formatting lints.

Author: Jarcho

clippy_lints/src/formatting.rs

@@ -510,6 +510,40 @@ impl<'sm> SourceFileRange<'sm> {
         self
     }
 
+    /// Sets the current range to the range between the current range and the given range.
+    /// Does nothing and returns `None` if the ranges overlap.
+    ///
+    /// With debug assertions enabled this will assert that the given range:
+    /// * Is within the same file as the current range.
+    /// * Lies on a UTF-8 boundary.
+    #[inline]
+    #[must_use]
+    #[cfg_attr(debug_assertions, track_caller)]
+    pub fn set_range_between_other(&mut self, other: impl SpanLike) -> Option<&mut Self> {
+        fn f<'a, 'sm>(
+            self_: &'a mut SourceFileRange<'sm>,
+            other: Range<BytePos>,
+        ) -> Option<&'a mut SourceFileRange<'sm>> {
+            let file = self_.file();
+            let other = other.into_range();
+            let other: Range<RelativeBytePos> = RelativeBytePos(other.start.0.wrapping_sub(file.start_pos.0))
+                ..RelativeBytePos(other.end.0.wrapping_sub(file.start_pos.0));
+            dbg_check_range(self_, other.clone());
+            if self_.range.end.0.cast_signed() < other.start.0.cast_signed() {
+                self_.range.start = self_.range.end;
+                self_.range.end = other.start;
+                Some(self_)
+            } else if self_.range.start.0.cast_signed() > other.end.0.cast_signed() {
+                self_.range.end = self_.range.start;
+                self_.range.start = other.end;
+                Some(self_)
+            } else {
+                None
+            }
+        }
+        f(self, other.into_range())
+    }
+
     /// Sets the start of this range to the given source map position if it's at or before
     /// the current range.
     ///

clippy_utils/src/source.rs

@@ -0,0 +1,74 @@
+//@aux-build:../auxiliary/proc_macros.rs
+#![deny(clippy::possible_missing_comma)]
+
+use proc_macros::{external, inline_macros, with_span};
+
+#[rustfmt::skip]
+#[inline_macros]
+fn main() {
+    {
+        let x = 20;
+        let y = &32;
+
+        let _ = [1, 2, *y]; //~ possible_missing_comma
+        let _ = [1, 2, -x]; //~ possible_missing_comma
+        let _ = [1, x - 2, -x]; //~ possible_missing_comma
+        let _ = [1, 2, -x - 2]; //~ possible_missing_comma
+        let _ = [1, 2 * x * 2, -x]; //~ possible_missing_comma
+
+        let _ = [
+            1,
+            x,
+            -2 * x * 2, //~ possible_missing_comma
+            -x, //~ possible_missing_comma
+        ];
+
+        let _ = (1, &x); //~ possible_missing_comma
+        let _ = (1, x, -1); //~ possible_missing_comma
+
+        let _ = (1-x);
+        let _ = (1- x);
+        let _ = (1 -/* comment */x);
+        let _ = (1, 2*y - 5);
+        let _ = (1, 2 /x);
+        let _ = (1, 2 <x);
+        let _ = (1, 2 !=x);
+        let _ = (1, 2 |x);
+        let _ = (1, 2 <<x);
+
+        let _ = [
+            1
+            - x,
+            x
+            * y,
+        ];
+    }
+
+    {
+        let x = true;
+        let y = false;
+
+        let _ = (y, &&x); //~ possible_missing_comma
+        let _ = (y && x);
+        let _ = (y&&x);
+    }
+
+    with_span! {
+        span
+        let x = 0;
+        let _ = (x -1);
+    }
+
+    external! {
+        let x = 0;
+        let _ = (x -1);
+    }
+
+    inline! {
+        let x = 0;
+        let _ = (x, -1); //~ possible_missing_comma
+        let _ = (x, -$(@tt 1)); //~ possible_missing_comma
+        let _ = ($(@expr x -1));
+        let _ = (x $(@tt -)1);
+    }
+}

tests/ui/formatting.rs

@@ -0,0 +1,74 @@
+//@aux-build:../auxiliary/proc_macros.rs
+#![deny(clippy::possible_missing_comma)]
+
+use proc_macros::{external, inline_macros, with_span};
+
+#[rustfmt::skip]
+#[inline_macros]
+fn main() {
+    {
+        let x = 20;
+        let y = &32;
+
+        let _ = [1, 2 * y]; //~ possible_missing_comma
+        let _ = [1, 2 - x]; //~ possible_missing_comma
+        let _ = [1, x - 2 - x]; //~ possible_missing_comma
+        let _ = [1, 2 - x - 2]; //~ possible_missing_comma
+        let _ = [1, 2 * x * 2 - x]; //~ possible_missing_comma
+
+        let _ = [
+            1,
+            x
+            - 2 * x * 2 //~ possible_missing_comma
+            - x, //~ possible_missing_comma
+        ];
+
+        let _ = (1 & x); //~ possible_missing_comma
+        let _ = (1, x - 1); //~ possible_missing_comma
+
+        let _ = (1-x);
+        let _ = (1- x);
+        let _ = (1 -/* comment */x);
+        let _ = (1, 2*y - 5);
+        let _ = (1, 2 /x);
+        let _ = (1, 2 <x);
+        let _ = (1, 2 !=x);
+        let _ = (1, 2 |x);
+        let _ = (1, 2 <<x);
+
+        let _ = [
+            1
+            - x,
+            x
+            * y,
+        ];
+    }
+
+    {
+        let x = true;
+        let y = false;
+
+        let _ = (y && x); //~ possible_missing_comma
+        let _ = (y && x);
+        let _ = (y&&x);
+    }
+
+    with_span! {
+        span
+        let x = 0;
+        let _ = (x -1);
+    }
+
+    external! {
+        let x = 0;
+        let _ = (x -1);
+    }
+
+    inline! {
+        let x = 0;
+        let _ = (x - 1); //~ possible_missing_comma
+        let _ = (x - $(@tt 1)); //~ possible_missing_comma
+        let _ = ($(@expr x -1));
+        let _ = (x $(@tt -)1);
+    }
+}