New upstream version 1.68.2+dfsg1

[rustc.git] / compiler / rustc_mir_build / src / thir / pattern / deconstruct_pat.rs

diff --git a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
index d60e8722cb61d5c443e20ef22d8c061d100781e0..aba5429da435f84292cb698a9e62d7d6b53b61ba 100644 (file)
--- a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
@@ -45,7 +45,7 @@
 use std::cell::Cell;
 use std::cmp::{self, max, min, Ordering};
 use std::fmt;
-use std::iter::{once, IntoIterator};
+use std::iter::once;
 use std::ops::RangeInclusive;
 
 use smallvec::{smallvec, SmallVec};
@@ -67,6 +67,7 @@ use self::SliceKind::*;
 
 use super::compare_const_vals;
 use super::usefulness::{MatchCheckCtxt, PatCtxt};
+use crate::errors::{Overlap, OverlappingRangeEndpoints};
 
 /// Recursively expand this pattern into its subpatterns. Only useful for or-patterns.
 fn expand_or_pat<'p, 'tcx>(pat: &'p Pat<'tcx>) -> Vec<&'p Pat<'tcx>> {
@@ -96,7 +97,7 @@ fn expand_or_pat<'p, 'tcx>(pat: &'p Pat<'tcx>) -> Vec<&'p Pat<'tcx>> {
 /// `IntRange` is never used to encode an empty range or a "range" that wraps
 /// around the (offset) space: i.e., `range.lo <= range.hi`.
 #[derive(Clone, PartialEq, Eq)]
-pub(super) struct IntRange {
+pub(crate) struct IntRange {
     range: RangeInclusive<u128>,
     /// Keeps the bias used for encoding the range. It depends on the type of the range and
     /// possibly the pointer size of the current architecture. The algorithm ensures we never
@@ -140,27 +141,22 @@ impl IntRange {
     ) -> Option<IntRange> {
         let ty = value.ty();
         if let Some((target_size, bias)) = Self::integral_size_and_signed_bias(tcx, ty) {
-            let val = (|| {
-                match value {
-                    mir::ConstantKind::Val(ConstValue::Scalar(scalar), _) => {
-                        // For this specific pattern we can skip a lot of effort and go
-                        // straight to the result, after doing a bit of checking. (We
-                        // could remove this branch and just fall through, which
-                        // is more general but much slower.)
-                        return scalar.to_bits_or_ptr_internal(target_size).unwrap().left();
-                    }
-                    mir::ConstantKind::Ty(c) => match c.kind() {
-                        ty::ConstKind::Value(_) => bug!(
-                            "encountered ConstValue in mir::ConstantKind::Ty, whereas this is expected to be in ConstantKind::Val"
-                        ),
-                        _ => {}
-                    },
-                    _ => {}
+            let val = if let mir::ConstantKind::Val(ConstValue::Scalar(scalar), _) = value {
+                // For this specific pattern we can skip a lot of effort and go
+                // straight to the result, after doing a bit of checking. (We
+                // could remove this branch and just fall through, which
+                // is more general but much slower.)
+                scalar.to_bits_or_ptr_internal(target_size).unwrap().left()?
+            } else {
+                if let mir::ConstantKind::Ty(c) = value
+                    && let ty::ConstKind::Value(_) = c.kind()
+                {
+                    bug!("encountered ConstValue in mir::ConstantKind::Ty, whereas this is expected to be in ConstantKind::Val");
                 }
 
                 // This is a more general form of the previous case.
-                value.try_eval_bits(tcx, param_env, ty)
-            })()?;
+                value.try_eval_bits(tcx, param_env, ty)?
+            };
             let val = val ^ bias;
             Some(IntRange { range: val..=val, bias })
         } else {
@@ -284,32 +280,21 @@ impl IntRange {
             return;
         }
 
-        let overlaps: Vec<_> = pats
+        let overlap: Vec<_> = pats
             .filter_map(|pat| Some((pat.ctor().as_int_range()?, pat.span())))
             .filter(|(range, _)| self.suspicious_intersection(range))
-            .map(|(range, span)| (self.intersection(&range).unwrap(), span))
+            .map(|(range, span)| Overlap {
+                range: self.intersection(&range).unwrap().to_pat(pcx.cx.tcx, pcx.ty),
+                span,
+            })
             .collect();
 
-        if !overlaps.is_empty() {
-            pcx.cx.tcx.struct_span_lint_hir(
+        if !overlap.is_empty() {
+            pcx.cx.tcx.emit_spanned_lint(
                 lint::builtin::OVERLAPPING_RANGE_ENDPOINTS,
                 hir_id,
                 pcx.span,
-                "multiple patterns overlap on their endpoints",
-                |lint| {
-                    for (int_range, span) in overlaps {
-                        lint.span_label(
-                            span,
-                            &format!(
-                                "this range overlaps on `{}`...",
-                                int_range.to_pat(pcx.cx.tcx, pcx.ty)
-                            ),
-                        );
-                    }
-                    lint.span_label(pcx.span, "... with this range");
-                    lint.note("you likely meant to write mutually exclusive ranges");
-                    lint
-                },
+                OverlappingRangeEndpoints { overlap, range: pcx.span },
             );
         }
     }
@@ -404,7 +389,7 @@ impl SplitIntRange {
     }
 
     /// Iterate over the contained ranges.
-    fn iter<'a>(&'a self) -> impl Iterator<Item = IntRange> + Captures<'a> {
+    fn iter(&self) -> impl Iterator<Item = IntRange> + Captures<'_> {
         use IntBorder::*;
 
         let self_range = Self::to_borders(self.range.clone());
@@ -612,7 +597,7 @@ impl SplitVarLenSlice {
     }
 
     /// Iterate over the partition of this slice.
-    fn iter<'a>(&'a self) -> impl Iterator<Item = Slice> + Captures<'a> {
+    fn iter(&self) -> impl Iterator<Item = Slice> + Captures<'_> {
         let smaller_lengths = match self.array_len {
             // The only admissible fixed-length slice is one of the array size. Whether `max_slice`
             // is fixed-length or variable-length, it will be the only relevant slice to output