Allow int literals for pattern types with int base types

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -1647,7 +1647,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ast::LitKind::Char(_) => tcx.types.char,
             ast::LitKind::Int(_, ast::LitIntType::Signed(t)) => Ty::new_int(tcx, ty::int_ty(t)),
             ast::LitKind::Int(_, ast::LitIntType::Unsigned(t)) => Ty::new_uint(tcx, ty::uint_ty(t)),
-            ast::LitKind::Int(_, ast::LitIntType::Unsuffixed) => {
+            ast::LitKind::Int(i, ast::LitIntType::Unsuffixed) => {
                 let opt_ty = expected.to_option(self).and_then(|ty| match ty.kind() {
                     ty::Int(_) | ty::Uint(_) => Some(ty),
                     // These exist to direct casts like `0x61 as char` to use
@@ -1656,6 +1656,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     ty::Char => Some(tcx.types.u8),
                     ty::RawPtr(..) => Some(tcx.types.usize),
                     ty::FnDef(..) | ty::FnPtr(..) => Some(tcx.types.usize),
+                    &ty::Pat(base, _) if base.is_integral() => {
+                        let layout = tcx
+                            .layout_of(self.typing_env(self.param_env).as_query_input(ty))
+                            .ok()?;
+                        assert!(!layout.uninhabited);
+
+                        match layout.backend_repr {
+                            rustc_abi::BackendRepr::Scalar(scalar) => {
+                                scalar.valid_range(&tcx).contains(u128::from(i.get())).then_some(ty)
+                            }
+                            _ => unreachable!(),
+                        }
+                    }
                     _ => None,
                 });
                 opt_ty.unwrap_or_else(|| self.next_int_var())

compiler/rustc_mir_build/src/builder/expr/as_constant.rs

@@ -117,7 +117,12 @@ fn lit_to_mir_constant<'tcx>(tcx: TyCtxt<'tcx>, lit_input: LitToConstInput<'tcx>
         ConstValue::Scalar(Scalar::from_uint(result, width))
     };
 
-    let value = match (lit, ty.kind()) {
+    let lit_ty = match *ty.kind() {
+        ty::Pat(base, _) => base,
+        _ => ty,
+    };
+
+    let value = match (lit, lit_ty.kind()) {
         (ast::LitKind::Str(s, _), ty::Ref(_, inner_ty, _)) if inner_ty.is_str() => {
             let s = s.as_str();
             let allocation = Allocation::from_bytes_byte_aligned_immutable(s.as_bytes());

tests/ui/type/pattern_types/literals.rs

@@ -12,27 +12,24 @@ fn out_of_range() -> pattern_type!(u32 is 1..) {
 
 fn at_range_start() -> pattern_type!(u32 is 1..) {
     1
-    //~^ mismatched types
 }
 
 fn in_range() -> pattern_type!(u32 is 1..) {
     2
-    //~^ mismatched types
 }
 
 fn negative_lit_on_unsigned_ty() -> pattern_type!(u32 is 1..) {
     -3
-    //~^ mismatched types
+    //~^ ERROR: cannot apply unary operator `-` to type `(u32) is 1..`
 }
 
 fn negative_lit_in_range() -> pattern_type!(i8 is -5..5) {
     -2
-    //~^ mismatched types
+    //~^ ERROR: cannot apply unary operator `-` to type `(i8) is -5..=4`
 }
 
 fn positive_lit_in_range_of_signed() -> pattern_type!(i8 is -5..5) {
     2
-    //~^ mismatched types
 }
 
 fn negative_lit_at_range_start() -> pattern_type!(i8 is -5..5) {
@@ -42,7 +39,6 @@ fn negative_lit_at_range_start() -> pattern_type!(i8 is -5..5) {
 
 fn positive_lit_at_range_end() -> pattern_type!(i8 is -5..5) {
     4
-    //~^ mismatched types
 }
 
 fn lit_one_beyond_range_end() -> pattern_type!(i8 is -5..5) {
@@ -67,12 +63,10 @@ fn char_lit_out_of_range() -> pattern_type!(char is 'a'..'z') {
 
 fn lit_at_unsigned_range_inclusive_end() -> pattern_type!(u32 is 0..=1) {
     1
-    //~^ mismatched types
 }
 
 fn single_element_range() -> pattern_type!(u32 is 0..=0) {
     0
-    //~^ mismatched types
 }
 
 fn lit_oob_single_element_range() -> pattern_type!(u32 is 0..=0) {
@@ -87,7 +81,6 @@ fn lit_oob_single_element_range_exclusive() -> pattern_type!(u32 is 0..1) {
 
 fn single_element_range_exclusive() -> pattern_type!(u32 is 0..1) {
     0
-    //~^ mismatched types
 }
 
 fn empty_range_at_base_type_min() -> pattern_type!(u32 is 0..0) {

tests/ui/type/pattern_types/literals.stderr

@@ -1,29 +1,29 @@
 error[E0080]: evaluation of constant value failed
-  --> $DIR/literals.rs:93:62
+  --> $DIR/literals.rs:86:62
    |
 LL | fn empty_range_at_base_type_min() -> pattern_type!(u32 is 0..0) {
    |                                                              ^ evaluation panicked: exclusive range end at minimum value of type
 
 error[E0080]: evaluation of constant value failed
-  --> $DIR/literals.rs:98:63
+  --> $DIR/literals.rs:91:63
    |
 LL | fn empty_range_at_base_type_min2() -> pattern_type!(u32 is 0..0) {
    |                                                               ^ evaluation panicked: exclusive range end at minimum value of type
 
 error[E0080]: evaluation of constant value failed
-  --> $DIR/literals.rs:113:65
+  --> $DIR/literals.rs:106:65
    |
 LL | fn wraparound_range_at_base_ty_end() -> pattern_type!(u32 is 1..0) {
    |                                                                 ^ evaluation panicked: exclusive range end at minimum value of type
 
 error[E0080]: evaluation of constant value failed
-  --> $DIR/literals.rs:118:66
+  --> $DIR/literals.rs:111:66
    |
 LL | fn wraparound_range_at_base_ty_end2() -> pattern_type!(u32 is 1..0) {
    |                                                                  ^ evaluation panicked: exclusive range end at minimum value of type
 
 error[E0080]: evaluation of constant value failed
-  --> $DIR/literals.rs:123:66
+  --> $DIR/literals.rs:116:66
    |
 LL | fn wraparound_range_at_base_ty_end3() -> pattern_type!(u32 is 1..0) {
    |                                                                  ^ evaluation panicked: exclusive range end at minimum value of type
@@ -39,63 +39,20 @@ LL |     0
    = note: expected pattern type `(u32) is 1..`
                       found type `{integer}`
 
-error[E0308]: mismatched types
+error[E0600]: cannot apply unary operator `-` to type `(u32) is 1..`
-  --> $DIR/literals.rs:14:5
+  --> $DIR/literals.rs:22:5
    |
-LL | fn at_range_start() -> pattern_type!(u32 is 1..) {
-   |                        ------------------------- expected `(u32) is 1..` because of return type
-LL |     1
-   |     ^ expected `(u32) is 1..`, found integer
-   |
-   = note: expected pattern type `(u32) is 1..`
-                      found type `{integer}`
-
-error[E0308]: mismatched types
-  --> $DIR/literals.rs:19:5
-   |
-LL | fn in_range() -> pattern_type!(u32 is 1..) {
-   |                  ------------------------- expected `(u32) is 1..` because of return type
-LL |     2
-   |     ^ expected `(u32) is 1..`, found integer
-   |
-   = note: expected pattern type `(u32) is 1..`
-                      found type `{integer}`
-
-error[E0308]: mismatched types
-  --> $DIR/literals.rs:24:5
-   |
-LL | fn negative_lit_on_unsigned_ty() -> pattern_type!(u32 is 1..) {
-   |                                     ------------------------- expected `(u32) is 1..` because of return type
 LL |     -3
-   |     ^^ expected `(u32) is 1..`, found integer
+   |     ^^ cannot apply unary operator `-`
-   |
-   = note: expected pattern type `(u32) is 1..`
-                      found type `{integer}`
 
-error[E0308]: mismatched types
+error[E0600]: cannot apply unary operator `-` to type `(i8) is -5..=4`
-  --> $DIR/literals.rs:29:5
+  --> $DIR/literals.rs:27:5
    |
-LL | fn negative_lit_in_range() -> pattern_type!(i8 is -5..5) {
-   |                               -------------------------- expected `(i8) is -5..=4` because of return type
 LL |     -2
-   |     ^^ expected `(i8) is -5..=4`, found integer
+   |     ^^ cannot apply unary operator `-`
-   |
-   = note: expected pattern type `(i8) is -5..=4`
-                      found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:34:5
+  --> $DIR/literals.rs:36:5
-   |
-LL | fn positive_lit_in_range_of_signed() -> pattern_type!(i8 is -5..5) {
-   |                                         -------------------------- expected `(i8) is -5..=4` because of return type
-LL |     2
-   |     ^ expected `(i8) is -5..=4`, found integer
-   |
-   = note: expected pattern type `(i8) is -5..=4`
-                      found type `{integer}`
-
-error[E0308]: mismatched types
-  --> $DIR/literals.rs:39:5
    |
 LL | fn negative_lit_at_range_start() -> pattern_type!(i8 is -5..5) {
    |                                     -------------------------- expected `(i8) is -5..=4` because of return type
@@ -106,18 +63,7 @@ LL |     -5
                       found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:44:5
+  --> $DIR/literals.rs:45:5
-   |
-LL | fn positive_lit_at_range_end() -> pattern_type!(i8 is -5..5) {
-   |                                   -------------------------- expected `(i8) is -5..=4` because of return type
-LL |     4
-   |     ^ expected `(i8) is -5..=4`, found integer
-   |
-   = note: expected pattern type `(i8) is -5..=4`
-                      found type `{integer}`
-
-error[E0308]: mismatched types
-  --> $DIR/literals.rs:49:5
    |
 LL | fn lit_one_beyond_range_end() -> pattern_type!(i8 is -5..5) {
    |                                  -------------------------- expected `(i8) is -5..=4` because of return type
@@ -128,7 +74,7 @@ LL |     5
                       found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:54:5
+  --> $DIR/literals.rs:50:5
    |
 LL | fn wrong_lit_kind() -> pattern_type!(u32 is 1..) {
    |                        ------------------------- expected `(u32) is 1..` because of return type
@@ -139,7 +85,7 @@ LL |     '3'
                       found type `char`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:59:5
+  --> $DIR/literals.rs:55:5
    |
 LL | fn char_lit_in_range() -> pattern_type!(char is 'a'..'z') {
    |                           ------------------------------- expected `(char) is 'a'..='y'` because of return type
@@ -150,7 +96,7 @@ LL |     'b'
                       found type `char`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:64:5
+  --> $DIR/literals.rs:60:5
    |
 LL | fn char_lit_out_of_range() -> pattern_type!(char is 'a'..'z') {
    |                               ------------------------------- expected `(char) is 'a'..='y'` because of return type
@@ -161,29 +107,7 @@ LL |     'A'
                       found type `char`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:69:5
+  --> $DIR/literals.rs:73:5
-   |
-LL | fn lit_at_unsigned_range_inclusive_end() -> pattern_type!(u32 is 0..=1) {
-   |                                             --------------------------- expected `(u32) is 0..=1` because of return type
-LL |     1
-   |     ^ expected `(u32) is 0..=1`, found integer
-   |
-   = note: expected pattern type `(u32) is 0..=1`
-                      found type `{integer}`
-
-error[E0308]: mismatched types
-  --> $DIR/literals.rs:74:5
-   |
-LL | fn single_element_range() -> pattern_type!(u32 is 0..=0) {
-   |                              --------------------------- expected `(u32) is 0..=0` because of return type
-LL |     0
-   |     ^ expected `(u32) is 0..=0`, found integer
-   |
-   = note: expected pattern type `(u32) is 0..=0`
-                      found type `{integer}`
-
-error[E0308]: mismatched types
-  --> $DIR/literals.rs:79:5
    |
 LL | fn lit_oob_single_element_range() -> pattern_type!(u32 is 0..=0) {
    |                                      --------------------------- expected `(u32) is 0..=0` because of return type
@@ -194,7 +118,7 @@ LL |     1
                       found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:84:5
+  --> $DIR/literals.rs:78:5
    |
 LL | fn lit_oob_single_element_range_exclusive() -> pattern_type!(u32 is 0..1) {
    |                                                -------------------------- expected `(u32) is 0..=0` because of return type
@@ -204,19 +128,10 @@ LL |     1
    = note: expected pattern type `(u32) is 0..=0`
                       found type `{integer}`
 
-error[E0308]: mismatched types
+error: pattern type ranges cannot wrap: 1..=0
-  --> $DIR/literals.rs:89:5
-   |
-LL | fn single_element_range_exclusive() -> pattern_type!(u32 is 0..1) {
-   |                                        -------------------------- expected `(u32) is 0..=0` because of return type
-LL |     0
-   |     ^ expected `(u32) is 0..=0`, found integer
-   |
-   = note: expected pattern type `(u32) is 0..=0`
-                      found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:104:5
+  --> $DIR/literals.rs:97:5
    |
 LL | fn empty_range() -> pattern_type!(u32 is 1..1) {
    |                     -------------------------- expected `(u32) is 1..=0` because of return type
@@ -227,7 +142,7 @@ LL |     0
                       found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:109:5
+  --> $DIR/literals.rs:102:5
    |
 LL | fn empty_range2() -> pattern_type!(u32 is 1..1) {
    |                      -------------------------- expected `(u32) is 1..=0` because of return type
@@ -237,8 +152,10 @@ LL |     1
    = note: expected pattern type `(u32) is 1..=0`
                       found type `{integer}`
 
+error: pattern type ranges cannot wrap: 2..=0
+
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:129:5
+  --> $DIR/literals.rs:122:5
    |
 LL | fn wraparound_range() -> pattern_type!(u32 is 2..1) {
    |                          -------------------------- expected `(u32) is 2..=0` because of return type
@@ -249,7 +166,7 @@ LL |     1
                       found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:134:5
+  --> $DIR/literals.rs:127:5
    |
 LL | fn lit_in_wraparound_range() -> pattern_type!(u32 is 2..1) {
    |                                 -------------------------- expected `(u32) is 2..=0` because of return type
@@ -260,7 +177,7 @@ LL |     0
                       found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/literals.rs:139:5
+  --> $DIR/literals.rs:132:5
    |
 LL | fn lit_at_wraparound_range_start() -> pattern_type!(u32 is 2..1) {
    |                                       -------------------------- expected `(u32) is 2..=0` because of return type
@@ -270,7 +187,7 @@ LL |     2
    = note: expected pattern type `(u32) is 2..=0`
                       found type `{integer}`
 
-error: aborting due to 27 previous errors
+error: aborting due to 22 previous errors
 
-Some errors have detailed explanations: E0080, E0308.
+Some errors have detailed explanations: E0080, E0308, E0600.
 For more information about an error, try `rustc --explain E0080`.

tests/ui/type/pattern_types/nested.rs

@@ -1,6 +1,6 @@
 //! Check that pattern types can only have specific base types
 
-#![feature(pattern_types)]
+#![feature(pattern_types, const_trait_impl, pattern_type_range_trait)]
 #![feature(pattern_type_macro)]
 
 use std::pat::pattern_type;
@@ -14,7 +14,7 @@ const BAD_NESTING: pattern_type!(pattern_type!(u32 is 1..) is 0..) = todo!();
 // We want to get the most narrowest version that a pattern could be
 const BAD_NESTING2: pattern_type!(pattern_type!(i32 is 1..) is ..=-1) = todo!();
 //~^ ERROR: not a valid base type for range patterns
-//~| ERROR: mismatched types
+//~| ERROR: cannot apply unary operator `-` to type `(i32) is 1..`
 
 const BAD_NESTING3: pattern_type!(pattern_type!(i32 is 1..) is ..0) = todo!();
 //~^ ERROR: not a valid base type for range patterns

tests/ui/type/pattern_types/nested.stderr

@@ -43,14 +43,11 @@ LL | const BAD_NESTING2: pattern_type!(pattern_type!(i32 is 1..) is ..=-1) = tod
              u128
            and 5 others
 
-error[E0308]: mismatched types
+error[E0600]: cannot apply unary operator `-` to type `(i32) is 1..`
   --> $DIR/nested.rs:15:67
    |
 LL | const BAD_NESTING2: pattern_type!(pattern_type!(i32 is 1..) is ..=-1) = todo!();
-   |                                                                   ^^ expected `(i32) is 1..`, found integer
+   |                                                                   ^^ cannot apply unary operator `-`
-   |
-   = note: expected pattern type `(i32) is 1..`
-                      found type `{integer}`
 
 error[E0277]: `(i32) is 1..` is not a valid base type for range patterns
   --> $DIR/nested.rs:19:35
@@ -180,5 +177,5 @@ LL | const BAD_NESTING5: pattern_type!(f32 is 1.0 .. 2.0) = todo!();
 
 error: aborting due to 11 previous errors
 
-Some errors have detailed explanations: E0277, E0308.
+Some errors have detailed explanations: E0277, E0308, E0600.
 For more information about an error, try `rustc --explain E0277`.