Hide the end of ranges in pretty printing if it's also the maximum of the type

oli-obk · oli-obk · commit 6b71f0cfdd69 · 2025-02-12T11:57:07.000Z
diff --git a/compiler/rustc_middle/src/ty/pattern.rs b/compiler/rustc_middle/src/ty/pattern.rs
@@ -28,7 +28,37 @@ impl<'tcx> fmt::Debug for PatternKind<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             PatternKind::Range { start, end, include_end } => {
-                write!(f, "{start}{include_end}{end}")
+                write!(f, "{start}")?;
+
+                match include_end {
+                    RangeEnd::Included => {
+                        if let Some(c) = end.try_to_value() {
+                            let end = c.valtree.unwrap_leaf();
+                            let size = end.size();
+                            let max = match c.ty.kind() {
+                                ty::Int(_) => Some(ty::ScalarInt::truncate_from_int(
+                                    size.signed_int_max(),
+                                    size,
+                                )),
+                                ty::Uint(_) => Some(ty::ScalarInt::truncate_from_uint(
+                                    size.unsigned_int_max(),
+                                    size,
+                                )),
+                                ty::Char => {
+                                    Some(ty::ScalarInt::truncate_from_uint(char::MAX, size))
+                                }
+                                _ => None,
+                            };
+                            if let Some((max, _)) = max
+                                && end == max
+                            {
+                                return write!(f, "..");
+                            }
+                        }
+                    }
+                    RangeEnd::Excluded => {}
+                }
+                write!(f, "{include_end}{end}")
             }
         }
     }
diff --git a/tests/mir-opt/pattern_types.main.PreCodegen.after.mir b/tests/mir-opt/pattern_types.main.PreCodegen.after.mir
@@ -3,9 +3,9 @@
 fn main() -> () {
     let mut _0: ();
     scope 1 {
-        debug x => const 2_u32 is 1..=u32::MAX;
+        debug x => const 2_u32 is 1..;
         scope 2 {
-            debug y => const {transmute(0x00000000): (u32) is 1..=u32::MAX};
+            debug y => const {transmute(0x00000000): (u32) is 1..};
         }
     }
 
diff --git a/tests/mir-opt/pattern_types.rs b/tests/mir-opt/pattern_types.rs
@@ -5,8 +5,8 @@ use std::pat::pattern_type;
 
 // EMIT_MIR pattern_types.main.PreCodegen.after.mir
 fn main() {
-    // CHECK: debug x => const 2_u32 is 1..=u32::MAX
+    // CHECK: debug x => const 2_u32 is 1..
     let x: pattern_type!(u32 is 1..) = unsafe { std::mem::transmute(2) };
-    // CHECK: debug y => const {transmute(0x00000000): (u32) is 1..=u32::MAX}
+    // CHECK: debug y => const {transmute(0x00000000): (u32) is 1..}
     let y: pattern_type!(u32 is 1..) = unsafe { std::mem::transmute(0) };
 }
diff --git a/tests/ui/lint/clashing-extern-fn.stderr b/tests/ui/lint/clashing-extern-fn.stderr
@@ -17,7 +17,7 @@ LL |             fn hidden_niche_unsafe_cell() -> Option<UnsafeCell<NonZero<usiz
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 
-warning: `extern` block uses type `Option<(usize) is 0..=usize::MAX>`, which is not FFI-safe
+warning: `extern` block uses type `Option<(usize) is 0..>`, which is not FFI-safe
   --> $DIR/clashing-extern-fn.rs:502:54
    |
 LL |             fn pt_non_zero_usize_opt_full_range() -> Option<pattern_type!(usize is 0..)>;
@@ -276,7 +276,7 @@ LL |             fn pt_non_null_ptr() -> pattern_type!(usize is 1..);
 LL |             fn pt_non_null_ptr() -> *const ();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this signature doesn't match the previous declaration
    |
-   = note: expected `unsafe extern "C" fn() -> (usize) is 1..=usize::MAX`
+   = note: expected `unsafe extern "C" fn() -> (usize) is 1..`
               found `unsafe extern "C" fn() -> *const ()`
 
 warning: 24 warnings emitted
diff --git a/tests/ui/type/pattern_types/nested.stderr b/tests/ui/type/pattern_types/nested.stderr
@@ -1,4 +1,4 @@
-error: `(u32) is 1..=u32::MAX` is not a valid base type for range patterns
+error: `(u32) is 1..` is not a valid base type for range patterns
   --> $DIR/nested.rs:10:34
    |
 LL | const BAD_NESTING: pattern_type!(pattern_type!(u32 is 1..) is 0..) = todo!();
@@ -10,7 +10,7 @@ note: range patterns only support integers
 LL | const BAD_NESTING: pattern_type!(pattern_type!(u32 is 1..) is 0..) = todo!();
    |                                                               ^^^
 
-error: `(i32) is 1..=i32::MAX` is not a valid base type for range patterns
+error: `(i32) is 1..` is not a valid base type for range patterns
   --> $DIR/nested.rs:15:35
    |
 LL | const BAD_NESTING2: pattern_type!(pattern_type!(i32 is 1..) is ..=-1) = todo!();
@@ -22,7 +22,7 @@ note: range patterns only support integers
 LL | const BAD_NESTING2: pattern_type!(pattern_type!(i32 is 1..) is ..=-1) = todo!();
    |                                                                ^^^^^
 
-error: `(i32) is 1..=i32::MAX` is not a valid base type for range patterns
+error: `(i32) is 1..` is not a valid base type for range patterns
   --> $DIR/nested.rs:19:35
    |
 LL | const BAD_NESTING3: pattern_type!(pattern_type!(i32 is 1..) is ..0) = todo!();
@@ -62,27 +62,27 @@ error[E0308]: mismatched types
   --> $DIR/nested.rs:10:63
    |
 LL | const BAD_NESTING: pattern_type!(pattern_type!(u32 is 1..) is 0..) = todo!();
-   |                                                               ^ expected `(u32) is 1..=u32::MAX`, found integer
+   |                                                               ^ expected `(u32) is 1..`, found integer
    |
-   = note: expected pattern type `(u32) is 1..=u32::MAX`
+   = note: expected pattern type `(u32) is 1..`
                       found type `{integer}`
 
 error[E0308]: mismatched types
   --> $DIR/nested.rs:15:67
    |
 LL | const BAD_NESTING2: pattern_type!(pattern_type!(i32 is 1..) is ..=-1) = todo!();
-   |                                                                   ^^ expected `(i32) is 1..=i32::MAX`, found integer
+   |                                                                   ^^ expected `(i32) is 1..`, found integer
    |
-   = note: expected pattern type `(i32) is 1..=i32::MAX`
+   = note: expected pattern type `(i32) is 1..`
                       found type `{integer}`
 
 error[E0308]: mismatched types
   --> $DIR/nested.rs:19:66
    |
 LL | const BAD_NESTING3: pattern_type!(pattern_type!(i32 is 1..) is ..0) = todo!();
-   |                                                                  ^ expected `(i32) is 1..=i32::MAX`, found integer
+   |                                                                  ^ expected `(i32) is 1..`, found integer
    |
-   = note: expected pattern type `(i32) is 1..=i32::MAX`
+   = note: expected pattern type `(i32) is 1..`
                       found type `{integer}`
 
 error[E0308]: mismatched types
diff --git a/tests/ui/type/pattern_types/range_patterns.stderr b/tests/ui/type/pattern_types/range_patterns.stderr
@@ -43,7 +43,7 @@ error: layout_of(NonZero<u32>) = Layout {
 LL | type X = std::num::NonZeroU32;
    | ^^^^^^
 
-error: layout_of((u32) is 1..=u32::MAX) = Layout {
+error: layout_of((u32) is 1..) = Layout {
            size: Size(4 bytes),
            align: AbiAndPrefAlign {
                abi: Align(4 bytes),
@@ -81,7 +81,7 @@ error: layout_of((u32) is 1..=u32::MAX) = Layout {
 LL | type Y = pattern_type!(u32 is 1..);
    | ^^^^^^
 
-error: layout_of(Option<(u32) is 1..=u32::MAX>) = Layout {
+error: layout_of(Option<(u32) is 1..>) = Layout {
            size: Size(4 bytes),
            align: AbiAndPrefAlign {
                abi: Align(4 bytes),
diff --git a/tests/ui/type/pattern_types/range_patterns_trait_impls2.stderr b/tests/ui/type/pattern_types/range_patterns_trait_impls2.stderr
@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar
 LL | impl Eq for Y {}
    | ^^^^^^^^^^^^-
    |             |
-   |             `(u32) is 1..=u32::MAX` is not defined in the current crate
+   |             `(u32) is 1..` is not defined in the current crate
    |
    = note: impl doesn't have any local type before any uncovered type parameters
    = note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules
diff --git a/tests/ui/type/pattern_types/range_patterns_unusable.stderr b/tests/ui/type/pattern_types/range_patterns_unusable.stderr
@@ -4,7 +4,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
 LL |     let _: Option<u32> = unsafe { std::mem::transmute(z) };
    |                                   ^^^^^^^^^^^^^^^^^^^
    |
-   = note: source type: `Option<(u32) is 1..=u32::MAX>` (32 bits)
+   = note: source type: `Option<(u32) is 1..>` (32 bits)
    = note: target type: `Option<u32>` (64 bits)
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/type/pattern_types/range_patterns_unusable_math.rs b/tests/ui/type/pattern_types/range_patterns_unusable_math.rs
@@ -11,5 +11,5 @@ type Z = Option<pattern_type!(u32 is 1..)>;
 
 fn main() {
     let x: Y = unsafe { std::mem::transmute(42_u32) };
-    let x = x + 1_u32; //~ ERROR cannot add `u32` to `(u32) is 1..=u32::MAX`
+    let x = x + 1_u32; //~ ERROR cannot add `u32` to `(u32) is 1..`
 }
diff --git a/tests/ui/type/pattern_types/range_patterns_unusable_math.stderr b/tests/ui/type/pattern_types/range_patterns_unusable_math.stderr
@@ -1,10 +1,10 @@
-error[E0369]: cannot add `u32` to `(u32) is 1..=u32::MAX`
+error[E0369]: cannot add `u32` to `(u32) is 1..`
   --> $DIR/range_patterns_unusable_math.rs:14:15
    |
 LL |     let x = x + 1_u32;
    |             - ^ ----- u32
    |             |
-   |             (u32) is 1..=u32::MAX
+   |             (u32) is 1..
 
 error: aborting due to 1 previous error
 

Original file line number	Diff line number	Diff line change
`@@ -3,9 +3,9 @@`
`3`	`3`	`fn main() -> () {`
`4`	`4`	`let mut _0: ();`
`5`	`5`	`scope 1 {`
`6`		`- debug x => const 2_u32 is 1..=u32::MAX;`
	`6`	`+ debug x => const 2_u32 is 1..;`
`7`	`7`	`scope 2 {`
`8`		`- debug y => const {transmute(0x00000000): (u32) is 1..=u32::MAX};`
	`8`	`+ debug y => const {transmute(0x00000000): (u32) is 1..};`
`9`	`9`	`}`
`10`	`10`	`}`
`11`	`11`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@ error[E0117]: only traits defined in the current crate can be implemented for ar`
`4`	`4`	`LL \| impl Eq for Y {}`
`5`	`5`	`\| ^^^^^^^^^^^^-`
`6`	`6`	`\| \|`
`7`		- \| `(u32) is 1..=u32::MAX` is not defined in the current crate
	`7`	+ \| `(u32) is 1..` is not defined in the current crate
`8`	`8`	`\|`
`9`	`9`	`= note: impl doesn't have any local type before any uncovered type parameters`
`10`	`10`	`= note: for more information see https://doc.rust-lang.org/reference/items/implementations.html#orphan-rules`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-`
`4`	`4`	`LL \| let _: Option<u32> = unsafe { std::mem::transmute(z) };`
`5`	`5`	`\| ^^^^^^^^^^^^^^^^^^^`
`6`	`6`	`\|`
`7`		- = note: source type: `Option<(u32) is 1..=u32::MAX>` (32 bits)
	`7`	+ = note: source type: `Option<(u32) is 1..>` (32 bits)
`8`	`8`	= note: target type: `Option<u32>` (64 bits)
`9`	`9`
`10`	`10`	`error: aborting due to 1 previous error`
Original file line number	Diff line number	Diff line change
`@@ -11,5 +11,5 @@ type Z = Option<pattern_type!(u32 is 1..)>;`
`11`	`11`
`12`	`12`	`fn main() {`
`13`	`13`	`let x: Y = unsafe { std::mem::transmute(42_u32) };`
`14`		- let x = x + 1_u32; //~ ERROR cannot add `u32` to `(u32) is 1..=u32::MAX`
	`14`	+ let x = x + 1_u32; //~ ERROR cannot add `u32` to `(u32) is 1..`
`15`	`15`	`}`