Start using pattern types in libcore

Author: oli-obk

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -459,7 +459,18 @@ pub(crate) fn type_di_node<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, t: Ty<'tcx>) ->
             AdtKind::Enum => enums::build_enum_type_di_node(cx, unique_type_id),
         },
         ty::Tuple(_) => build_tuple_type_di_node(cx, unique_type_id),
-        _ => bug!("debuginfo: unexpected type in type_di_node(): {:?}", t),
+        ty::Pat(base, _) => return type_di_node(cx, base),
+        // FIXME(unsafe_binders): impl debug info
+        ty::UnsafeBinder(_) => unimplemented!(),
+        ty::Alias(..)
+        | ty::Param(_)
+        | ty::Bound(..)
+        | ty::Infer(_)
+        | ty::Placeholder(_)
+        | ty::CoroutineWitness(..)
+        | ty::Error(_) => {
+            bug!("debuginfo: unexpected type in type_di_node(): {:?}", t)
+        }
     };
 
     {

compiler/rustc_const_eval/src/interpret/call.rs

@@ -86,6 +86,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 let (_, field) = layout.non_1zst_field(self).unwrap();
                 self.unfold_transparent(field, may_unfold)
             }
+            ty::Pat(base, _) => self.layout_of(*base).expect(
+                "if the layout of a pattern type could be computed, so can the layout of its base",
+            ),
             // Not a transparent type, no further unfolding.
             _ => layout,
         }

library/core/src/lib.rs

@@ -168,6 +168,8 @@
 #![feature(never_type)]
 #![feature(no_core)]
 #![feature(optimize_attribute)]
+#![feature(pattern_type_macro)]
+#![feature(pattern_types)]
 #![feature(prelude_import)]
 #![feature(repr_simd)]
 #![feature(rustc_allow_const_fn_unstable)]

library/core/src/num/niche_types.rs

@@ -5,60 +5,48 @@
 )]
 
 use crate::cmp::Ordering;
-use crate::fmt;
 use crate::hash::{Hash, Hasher};
 use crate::marker::StructuralPartialEq;
+use crate::{fmt, pattern_type};
 
 macro_rules! define_valid_range_type {
     ($(
         $(#[$m:meta])*
-        $vis:vis struct $name:ident($int:ident as $uint:ident in $low:literal..=$high:literal);
+        $vis:vis struct $name:ident($int:ident is $pat:pat);
     )+) => {$(
-        #[derive(Clone, Copy, Eq)]
+        #[derive(Clone, Copy)]
         #[repr(transparent)]
-        #[rustc_layout_scalar_valid_range_start($low)]
-        #[rustc_layout_scalar_valid_range_end($high)]
         $(#[$m])*
-        $vis struct $name($int);
-
-        const _: () = {
-            // With the `valid_range` attributes, it's always specified as unsigned
-            assert!(<$uint>::MIN == 0);
-            let ulow: $uint = $low;
-            let uhigh: $uint = $high;
-            assert!(ulow <= uhigh);
-
-            assert!(size_of::<$int>() == size_of::<$uint>());
-        };
-
+        $vis struct $name(pattern_type!($int is $pat));
         impl $name {
             #[inline]
             pub const fn new(val: $int) -> Option<Self> {
-                if (val as $uint) >= ($low as $uint) && (val as $uint) <= ($high as $uint) {
-                    // SAFETY: just checked the inclusive range
-                    Some(unsafe { $name(val) })
+                #[allow(non_contiguous_range_endpoints)]
+                if let $pat = val {
+                    // SAFETY: just checked that the value matches the pattern
+                    Some(unsafe { $name(crate::mem::transmute(val)) })
                 } else {
                     None
                 }
             }
 
             /// Constructs an instance of this type from the underlying integer
-            /// primitive without checking whether its zero.
+            /// primitive without checking whether its valid.
             ///
             /// # Safety
-            /// Immediate language UB if `val == 0`, as it violates the validity
+            /// Immediate language UB if `val` is not in the range of the pattern type,
+            /// as it violates the validity
             /// invariant of this type.
             #[inline]
             pub const unsafe fn new_unchecked(val: $int) -> Self {
-                // SAFETY: Caller promised that `val` is non-zero.
-                unsafe { $name(val) }
+                // SAFETY: Caller promised that `val` is in the valid range.
+                unsafe { $name(crate::mem::transmute(val)) }
             }
 
             #[inline]
             pub const fn as_inner(self) -> $int {
-                // SAFETY: This is a transparent wrapper, so unwrapping it is sound
-                // (Not using `.0` due to MCP#807.)
-                unsafe { crate::mem::transmute(self) }
+                // SAFETY: pattern types are always legal values of their base type
+                unsafe { crate::mem::transmute(self.0) }
             }
         }
 
@@ -67,6 +55,8 @@ macro_rules! define_valid_range_type {
         // by <https://github.com/rust-lang/compiler-team/issues/807>.
         impl StructuralPartialEq for $name {}
 
+        impl Eq for $name {}
+
         impl PartialEq for $name {
             #[inline]
             fn eq(&self, other: &Self) -> bool {
@@ -104,7 +94,7 @@ macro_rules! define_valid_range_type {
 }
 
 define_valid_range_type! {
-    pub struct Nanoseconds(u32 as u32 in 0..=999_999_999);
+    pub struct Nanoseconds(u32 is 0..=999_999_999);
 }
 
 impl Nanoseconds {
@@ -119,45 +109,30 @@ impl Default for Nanoseconds {
     }
 }
 
-define_valid_range_type! {
-    pub struct NonZeroU8Inner(u8 as u8 in 1..=0xff);
-    pub struct NonZeroU16Inner(u16 as u16 in 1..=0xff_ff);
-    pub struct NonZeroU32Inner(u32 as u32 in 1..=0xffff_ffff);
-    pub struct NonZeroU64Inner(u64 as u64 in 1..=0xffffffff_ffffffff);
-    pub struct NonZeroU128Inner(u128 as u128 in 1..=0xffffffffffffffff_ffffffffffffffff);
-
-    pub struct NonZeroI8Inner(i8 as u8 in 1..=0xff);
-    pub struct NonZeroI16Inner(i16 as u16 in 1..=0xff_ff);
-    pub struct NonZeroI32Inner(i32 as u32 in 1..=0xffff_ffff);
-    pub struct NonZeroI64Inner(i64 as u64 in 1..=0xffffffff_ffffffff);
-    pub struct NonZeroI128Inner(i128 as u128 in 1..=0xffffffffffffffff_ffffffffffffffff);
-}
-
-#[cfg(target_pointer_width = "16")]
-define_valid_range_type! {
-    pub struct UsizeNoHighBit(usize as usize in 0..=0x7fff);
-    pub struct NonZeroUsizeInner(usize as usize in 1..=0xffff);
-    pub struct NonZeroIsizeInner(isize as usize in 1..=0xffff);
-}
-#[cfg(target_pointer_width = "32")]
-define_valid_range_type! {
-    pub struct UsizeNoHighBit(usize as usize in 0..=0x7fff_ffff);
-    pub struct NonZeroUsizeInner(usize as usize in 1..=0xffff_ffff);
-    pub struct NonZeroIsizeInner(isize as usize in 1..=0xffff_ffff);
-}
-#[cfg(target_pointer_width = "64")]
-define_valid_range_type! {
-    pub struct UsizeNoHighBit(usize as usize in 0..=0x7fff_ffff_ffff_ffff);
-    pub struct NonZeroUsizeInner(usize as usize in 1..=0xffff_ffff_ffff_ffff);
-    pub struct NonZeroIsizeInner(isize as usize in 1..=0xffff_ffff_ffff_ffff);
-}
+const HALF_USIZE: usize = usize::MAX >> 1;
 
 define_valid_range_type! {
-    pub struct U32NotAllOnes(u32 as u32 in 0..=0xffff_fffe);
-    pub struct I32NotAllOnes(i32 as u32 in 0..=0xffff_fffe);
-
-    pub struct U64NotAllOnes(u64 as u64 in 0..=0xffff_ffff_ffff_fffe);
-    pub struct I64NotAllOnes(i64 as u64 in 0..=0xffff_ffff_ffff_fffe);
+    pub struct NonZeroU8Inner(u8 is 1..);
+    pub struct NonZeroU16Inner(u16 is 1..);
+    pub struct NonZeroU32Inner(u32 is 1..);
+    pub struct NonZeroU64Inner(u64 is 1..);
+    pub struct NonZeroU128Inner(u128 is 1..);
+
+    pub struct NonZeroI8Inner(i8 is ..0 | 1..);
+    pub struct NonZeroI16Inner(i16 is ..0 | 1..);
+    pub struct NonZeroI32Inner(i32 is ..0 | 1..);
+    pub struct NonZeroI64Inner(i64 is ..0 | 1..);
+    pub struct NonZeroI128Inner(i128 is ..0 | 1..);
+
+    pub struct UsizeNoHighBit(usize is 0..=HALF_USIZE);
+    pub struct NonZeroUsizeInner(usize is 1..);
+    pub struct NonZeroIsizeInner(isize is ..0 | 1..);
+
+    pub struct U32NotAllOnes(u32 is 0..u32::MAX);
+    pub struct I32NotAllOnes(i32 is ..-1 | 0..);
+
+    pub struct U64NotAllOnes(u64 is 0..u64::MAX);
+    pub struct I64NotAllOnes(i64 is ..-1 | 0..);
 }
 
 pub trait NotAllOnesHelper {

src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_callee_ret.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error: Undefined Behavior: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> tests/fail/validity/cast_fn_ptr_invalid_callee_ret.rs:LL:CC
    |
 LL |     f();
-   |     ^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+   |     ^^^ constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_caller_arg.stderr

@@ -1,8 +1,8 @@
-error: Undefined Behavior: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error: Undefined Behavior: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> tests/fail/validity/cast_fn_ptr_invalid_caller_arg.rs:LL:CC
    |
 LL |             Call(_res = f(*ptr), ReturnTo(retblock), UnwindContinue())
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.32bit.panic-abort.diff

@@ -45,7 +45,7 @@
           StorageLive(_4);
           StorageLive(_5);
           StorageLive(_6);
-          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
+          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
           _7 = const {0x1 as *const [bool; 0]};
           _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.32bit.panic-unwind.diff

@@ -45,7 +45,7 @@
           StorageLive(_4);
           StorageLive(_5);
           StorageLive(_6);
-          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
+          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
           _7 = const {0x1 as *const [bool; 0]};
           _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.64bit.panic-abort.diff

@@ -45,7 +45,7 @@
           StorageLive(_4);
           StorageLive(_5);
           StorageLive(_6);
-          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
+          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
           _7 = const {0x1 as *const [bool; 0]};
           _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.DataflowConstProp.64bit.panic-unwind.diff

@@ -45,7 +45,7 @@
           StorageLive(_4);
           StorageLive(_5);
           StorageLive(_6);
-          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
+          _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
           _7 = const {0x1 as *const [bool; 0]};
           _5 = const NonNull::<[bool; 0]> {{ pointer: {0x1 as *const [bool; 0]} }};

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.32bit.panic-abort.diff

@@ -46,7 +46,7 @@
           StorageLive(_5);
           StorageLive(_6);
 -         _6 = const std::ptr::Alignment::of::<[bool; 0]>::{constant#0} as std::num::NonZero<usize> (Transmute);
-+         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
++         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
 -         _7 = copy _6 as *const [bool; 0] (Transmute);
 -         _5 = NonNull::<[bool; 0]> { pointer: copy _7 };

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.32bit.panic-unwind.diff

@@ -46,7 +46,7 @@
           StorageLive(_5);
           StorageLive(_6);
 -         _6 = const std::ptr::Alignment::of::<[bool; 0]>::{constant#0} as std::num::NonZero<usize> (Transmute);
-+         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
++         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
 -         _7 = copy _6 as *const [bool; 0] (Transmute);
 -         _5 = NonNull::<[bool; 0]> { pointer: copy _7 };

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.64bit.panic-abort.diff

@@ -46,7 +46,7 @@
           StorageLive(_5);
           StorageLive(_6);
 -         _6 = const std::ptr::Alignment::of::<[bool; 0]>::{constant#0} as std::num::NonZero<usize> (Transmute);
-+         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
++         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
 -         _7 = copy _6 as *const [bool; 0] (Transmute);
 -         _5 = NonNull::<[bool; 0]> { pointer: copy _7 };

tests/mir-opt/dataflow-const-prop/default_boxed_slice.main.GVN.64bit.panic-unwind.diff

@@ -46,7 +46,7 @@
           StorageLive(_5);
           StorageLive(_6);
 -         _6 = const std::ptr::Alignment::of::<[bool; 0]>::{constant#0} as std::num::NonZero<usize> (Transmute);
-+         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
++         _6 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
           StorageLive(_7);
 -         _7 = copy _6 as *const [bool; 0] (Transmute);
 -         _5 = NonNull::<[bool; 0]> { pointer: copy _7 };

tests/mir-opt/gvn_ptr_eq_with_constant.main.GVN.diff

@@ -42,7 +42,7 @@
           StorageLive(_3);
 -         _3 = const std::ptr::Alignment::of::<u8>::{constant#0} as std::num::NonZero<usize> (Transmute);
 -         _2 = copy _3 as *mut u8 (Transmute);
-+         _3 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize));
++         _3 = const NonZero::<usize>(core::num::niche_types::NonZeroUsizeInner(1_usize is 1..));
 +         _2 = const {0x1 as *mut u8};
           StorageDead(_3);
           StorageLive(_4);

tests/ui/consts/const-eval/raw-bytes.32bit.stderr

@@ -64,7 +64,7 @@ LL | const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
                00 00 00 00                                     │ ....
            }
 
-error[E0080]: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error[E0080]: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> $DIR/raw-bytes.rs:61:1
    |
 LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
@@ -75,7 +75,7 @@ LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
                00                                              │ .
            }
 
-error[E0080]: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error[E0080]: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> $DIR/raw-bytes.rs:63:1
    |
 LL | const NULL_USIZE: NonZero<usize> = unsafe { mem::transmute(0usize) };

tests/ui/consts/const-eval/raw-bytes.64bit.stderr

@@ -64,7 +64,7 @@ LL | const NULL_PTR: NonNull<u8> = unsafe { mem::transmute(0usize) };
                00 00 00 00 00 00 00 00                         │ ........
            }
 
-error[E0080]: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error[E0080]: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> $DIR/raw-bytes.rs:61:1
    |
 LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
@@ -75,7 +75,7 @@ LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
                00                                              │ .
            }
 
-error[E0080]: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error[E0080]: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> $DIR/raw-bytes.rs:63:1
    |
 LL | const NULL_USIZE: NonZero<usize> = unsafe { mem::transmute(0usize) };

tests/ui/consts/const-eval/ub-nonnull.stderr

@@ -15,7 +15,7 @@ error[E0080]: in-bounds pointer arithmetic failed: attempting to offset pointer
 LL |     let out_of_bounds_ptr = &ptr[255];
    |                             ^^^^^^^^^ evaluation of constant value failed here
 
-error[E0080]: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error[E0080]: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> $DIR/ub-nonnull.rs:26:1
    |
 LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
@@ -26,7 +26,7 @@ LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
                HEX_DUMP
            }
 
-error[E0080]: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
+error[E0080]: constructing invalid value at .0.0: encountered 0, but expected something greater or equal to 1
   --> $DIR/ub-nonnull.rs:28:1
    |
 LL | const NULL_USIZE: NonZero<usize> = unsafe { mem::transmute(0usize) };

tests/ui/lint/invalid_value.stderr

@@ -333,7 +333,6 @@ LL |         let _val: (NonZero<u32>, i32) = mem::uninitialized();
    |
    = note: `std::num::NonZero<u32>` must be non-null
    = note: because `core::num::niche_types::NonZeroU32Inner` must be non-null
-   = note: integers must be initialized
 
 error: the type `*const dyn Send` does not permit zero-initialization
   --> $DIR/invalid_value.rs:97:37
@@ -430,7 +429,6 @@ note: because `std::num::NonZero<u32>` must be non-null (in this field of the on
 LL |     Banana(NonZero<u32>),
    |            ^^^^^^^^^^^^
    = note: because `core::num::niche_types::NonZeroU32Inner` must be non-null
-   = note: integers must be initialized
 
 error: the type `bool` does not permit being left uninitialized
   --> $DIR/invalid_value.rs:111:26