Auto merge of rust-lang#115889 - matthiaskrgr:rollup-kfmauvh, r=matth…

…iaskrgr

Rollup of 2 pull requests

Successful merges:

 - rust-lang#115607 (clarify that unsafe code must not rely on our safe traits)
 - rust-lang#115866 (make interpreter and TyAndLayout type Debug impl independent of Ty debug impl)

Failed merges:

 - rust-lang#115873 (Make `TyKind::Adt`'s `Debug` impl be more pretty)
 - rust-lang#115884 (make ty::Const debug printing less verbose)

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -136,7 +136,11 @@ impl<Prov: Provenance> std::fmt::Display for ImmTy<'_, Prov> {
 
 impl<Prov: Provenance> std::fmt::Debug for ImmTy<'_, Prov> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("ImmTy").field("imm", &self.imm).field("ty", &self.layout.ty).finish()
+        // Printing `layout` results in too much noise; just print a nice version of the type.
+        f.debug_struct("ImmTy")
+            .field("imm", &self.imm)
+            .field("ty", &format_args!("{}", self.layout.ty))
+            .finish()
     }
 }
 
@@ -305,7 +309,11 @@ pub struct OpTy<'tcx, Prov: Provenance = AllocId> {
 
 impl<Prov: Provenance> std::fmt::Debug for OpTy<'_, Prov> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("OpTy").field("op", &self.op).field("ty", &self.layout.ty).finish()
+        // Printing `layout` results in too much noise; just print a nice version of the type.
+        f.debug_struct("OpTy")
+            .field("op", &self.op)
+            .field("ty", &format_args!("{}", self.layout.ty))
+            .finish()
     }
 }
 

compiler/rustc_const_eval/src/interpret/place.rs

@@ -117,9 +117,10 @@ pub struct MPlaceTy<'tcx, Prov: Provenance = AllocId> {
 
 impl<Prov: Provenance> std::fmt::Debug for MPlaceTy<'_, Prov> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        // Printing `layout` results in too much noise; just print a nice version of the type.
         f.debug_struct("MPlaceTy")
             .field("mplace", &self.mplace)
-            .field("ty", &self.layout.ty)
+            .field("ty", &format_args!("{}", self.layout.ty))
             .finish()
     }
 }
@@ -237,7 +238,11 @@ pub struct PlaceTy<'tcx, Prov: Provenance = AllocId> {
 
 impl<Prov: Provenance> std::fmt::Debug for PlaceTy<'_, Prov> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("PlaceTy").field("place", &self.place).field("ty", &self.layout.ty).finish()
+        // Printing `layout` results in too much noise; just print a nice version of the type.
+        f.debug_struct("PlaceTy")
+            .field("place", &self.place)
+            .field("ty", &format_args!("{}", self.layout.ty))
+            .finish()
     }
 }
 

compiler/rustc_target/src/abi/call/mod.rs

@@ -2,6 +2,7 @@ use crate::abi::{self, Abi, Align, FieldsShape, Size};
 use crate::abi::{HasDataLayout, TyAbiInterface, TyAndLayout};
 use crate::spec::{self, HasTargetSpec};
 use rustc_span::Symbol;
+use std::fmt;
 use std::str::FromStr;
 
 mod aarch64;
@@ -515,12 +516,20 @@ impl<'a, Ty> TyAndLayout<'a, Ty> {
 
 /// Information about how to pass an argument to,
 /// or return a value from, a function, under some ABI.
-#[derive(Clone, PartialEq, Eq, Hash, Debug, HashStable_Generic)]
+#[derive(Clone, PartialEq, Eq, Hash, HashStable_Generic)]
 pub struct ArgAbi<'a, Ty> {
     pub layout: TyAndLayout<'a, Ty>,
     pub mode: PassMode,
 }
 
+// Needs to be a custom impl because of the bounds on the `TyAndLayout` debug impl.
+impl<'a, Ty: fmt::Display> fmt::Debug for ArgAbi<'a, Ty> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let ArgAbi { layout, mode } = self;
+        f.debug_struct("ArgAbi").field("layout", layout).field("mode", mode).finish()
+    }
+}
+
 impl<'a, Ty> ArgAbi<'a, Ty> {
     /// This defines the "default ABI" for that type, that is then later adjusted in `fn_abi_adjust_for_abi`.
     pub fn new(
@@ -694,7 +703,7 @@ impl RiscvInterruptKind {
 ///
 /// I will do my best to describe this structure, but these
 /// comments are reverse-engineered and may be inaccurate. -NDM
-#[derive(Clone, PartialEq, Eq, Hash, Debug, HashStable_Generic)]
+#[derive(Clone, PartialEq, Eq, Hash, HashStable_Generic)]
 pub struct FnAbi<'a, Ty> {
     /// The LLVM types of each argument.
     pub args: Box<[ArgAbi<'a, Ty>]>,
@@ -715,6 +724,21 @@ pub struct FnAbi<'a, Ty> {
     pub can_unwind: bool,
 }
 
+// Needs to be a custom impl because of the bounds on the `TyAndLayout` debug impl.
+impl<'a, Ty: fmt::Display> fmt::Debug for FnAbi<'a, Ty> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let FnAbi { args, ret, c_variadic, fixed_count, conv, can_unwind } = self;
+        f.debug_struct("FnAbi")
+            .field("args", args)
+            .field("ret", ret)
+            .field("c_variadic", c_variadic)
+            .field("fixed_count", fixed_count)
+            .field("conv", conv)
+            .field("can_unwind", can_unwind)
+            .finish()
+    }
+}
+
 /// Error produced by attempting to adjust a `FnAbi`, for a "foreign" ABI.
 #[derive(Copy, Clone, Debug, HashStable_Generic)]
 pub enum AdjustForForeignAbiError {

compiler/rustc_target/src/abi/mod.rs

@@ -3,6 +3,7 @@ pub use Primitive::*;
 
 use crate::json::{Json, ToJson};
 
+use std::fmt;
 use std::ops::Deref;
 
 use rustc_macros::HashStable_Generic;
@@ -24,12 +25,22 @@ impl ToJson for Endian {
 /// to that obtained from `layout_of(ty)`, as we need to produce
 /// layouts for which Rust types do not exist, such as enum variants
 /// or synthetic fields of enums (i.e., discriminants) and fat pointers.
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable_Generic)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, HashStable_Generic)]
 pub struct TyAndLayout<'a, Ty> {
     pub ty: Ty,
     pub layout: Layout<'a>,
 }
 
+impl<'a, Ty: fmt::Display> fmt::Debug for TyAndLayout<'a, Ty> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Print the type in a readable way, not its debug representation.
+        f.debug_struct("TyAndLayout")
+            .field("ty", &format_args!("{}", self.ty))
+            .field("layout", &self.layout)
+            .finish()
+    }
+}
+
 impl<'a, Ty> Deref for TyAndLayout<'a, Ty> {
     type Target = &'a LayoutS;
     fn deref(&self) -> &&'a LayoutS {

library/core/src/cmp.rs

@@ -63,6 +63,11 @@ use self::Ordering::*;
 /// (transitive) impls are not forced to exist, but these requirements apply
 /// whenever they do exist.
 ///
+/// Violating these requirements is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of these
+/// methods.
+///
 /// ## Derivable
 ///
 /// This trait can be used with `#[derive]`. When `derive`d on structs, two
@@ -250,6 +255,11 @@ pub macro PartialEq($item:item) {
 /// This property cannot be checked by the compiler, and therefore `Eq` implies
 /// [`PartialEq`], and has no extra methods.
 ///
+/// Violating this property is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of these
+/// methods.
+///
 /// ## Derivable
 ///
 /// This trait can be used with `#[derive]`. When `derive`d, because `Eq` has
@@ -659,6 +669,11 @@ impl<T: Clone> Clone for Reverse<T> {
 /// It's easy to accidentally make `cmp` and `partial_cmp` disagree by
 /// deriving some of the traits and manually implementing others.
 ///
+/// Violating these requirements is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of these
+/// methods.
+///
 /// ## Corollaries
 ///
 /// From the above and the requirements of `PartialOrd`, it follows that `<` defines a strict total order.
@@ -892,6 +907,11 @@ pub macro Ord($item:item) {
 /// transitively: if `T: PartialOrd<U>` and `U: PartialOrd<V>` then `U: PartialOrd<T>` and `T:
 /// PartialOrd<V>`.
 ///
+/// Violating these requirements is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of these
+/// methods.
+///
 /// ## Corollaries
 ///
 /// The following corollaries follow from the above requirements:

library/core/src/hash/mod.rs

@@ -153,6 +153,11 @@ mod sip;
 /// Thankfully, you won't need to worry about upholding this property when
 /// deriving both [`Eq`] and `Hash` with `#[derive(PartialEq, Eq, Hash)]`.
 ///
+/// Violating this property is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of these
+/// methods.
+///
 /// ## Prefix collisions
 ///
 /// Implementations of `hash` should ensure that the data they

library/core/src/ops/deref.rs

@@ -14,6 +14,11 @@
 /// For similar reasons, **this trait should never fail**. Failure during
 /// dereferencing can be extremely confusing when `Deref` is invoked implicitly.
 ///
+/// Violating these requirements is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of this
+/// method.
+///
 /// # More on `Deref` coercion
 ///
 /// If `T` implements `Deref<Target = U>`, and `x` is a value of type `T`, then:
@@ -114,6 +119,11 @@ impl<T: ?Sized> Deref for &mut T {
 /// dereferencing can be extremely confusing when `DerefMut` is invoked
 /// implicitly.
 ///
+/// Violating these requirements is a logic error. The behavior resulting from a logic error is not
+/// specified, but users of the trait must ensure that such logic errors do *not* result in
+/// undefined behavior. This means that `unsafe` code **must not** rely on the correctness of this
+/// method.
+///
 /// # More on `Deref` coercion
 ///
 /// If `T` implements `DerefMut<Target = U>`, and `x` is a value of type `T`,

tests/ui/abi/debug.rs

@@ -4,7 +4,6 @@
 // normalize-stderr-test "(valid_range): 0\.\.=(4294967295|18446744073709551615)" -> "$1: $$FULL"
 // This pattern is prepared for when we account for alignment in the niche.
 // normalize-stderr-test "(valid_range): [1-9]\.\.=(429496729[0-9]|1844674407370955161[0-9])" -> "$1: $$NON_NULL"
-// normalize-stderr-test "Leaf\(0x0*20\)" -> "Leaf(0x0...20)"
 // Some attributes are only computed for release builds:
 // compile-flags: -O
 #![feature(rustc_attrs)]

tests/ui/abi/debug.stderr

@@ -87,7 +87,7 @@ error: fn_abi_of(test) = FnAbi {
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:16:1
+  --> $DIR/debug.rs:15:1
    |
 LL | fn test(_x: u8) -> bool { true }
    | ^^^^^^^^^^^^^^^^^^^^^^^
@@ -181,7 +181,7 @@ error: fn_abi_of(TestFnPtr) = FnAbi {
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:19:1
+  --> $DIR/debug.rs:18:1
    |
 LL | type TestFnPtr = fn(bool) -> u8;
    | ^^^^^^^^^^^^^^
@@ -190,7 +190,7 @@ error: fn_abi_of(test_generic) = FnAbi {
            args: [
                ArgAbi {
                    layout: TyAndLayout {
-                       ty: *const T/#0,
+                       ty: *const T,
                        layout: Layout {
                            size: $SOME_SIZE,
                            align: AbiAndPrefAlign {
@@ -257,13 +257,13 @@ error: fn_abi_of(test_generic) = FnAbi {
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:22:1
+  --> $DIR/debug.rs:21:1
    |
 LL | fn test_generic<T>(_x: *const T) { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `#[rustc_abi]` can only be applied to function items, type aliases, and associated functions
-  --> $DIR/debug.rs:25:1
+  --> $DIR/debug.rs:24:1
    |
 LL | const C: () = ();
    | ^^^^^^^^^^^
@@ -409,7 +409,7 @@ error: ABIs are not compatible
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:41:1
+  --> $DIR/debug.rs:40:1
    |
 LL | type TestAbiNe = (fn(u8), fn(u32));
    | ^^^^^^^^^^^^^^
@@ -419,7 +419,7 @@ error: ABIs are not compatible
            args: [
                ArgAbi {
                    layout: TyAndLayout {
-                       ty: [u8; Const { ty: usize, kind: Leaf(0x0...20) }],
+                       ty: [u8; 32],
                        layout: Layout {
                            size: Size(32 bytes),
                            align: AbiAndPrefAlign {
@@ -490,7 +490,7 @@ error: ABIs are not compatible
            args: [
                ArgAbi {
                    layout: TyAndLayout {
-                       ty: [u32; Const { ty: usize, kind: Leaf(0x0...20) }],
+                       ty: [u32; 32],
                        layout: Layout {
                            size: Size(128 bytes),
                            align: AbiAndPrefAlign {
@@ -557,7 +557,7 @@ error: ABIs are not compatible
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:44:1
+  --> $DIR/debug.rs:43:1
    |
 LL | type TestAbiNeLarger = (fn([u8; 32]), fn([u32; 32]));
    | ^^^^^^^^^^^^^^^^^^^^
@@ -700,7 +700,7 @@ error: ABIs are not compatible
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:47:1
+  --> $DIR/debug.rs:46:1
    |
 LL | type TestAbiNeFloat = (fn(f32), fn(u32));
    | ^^^^^^^^^^^^^^^^^^^
@@ -846,13 +846,13 @@ error: ABIs are not compatible
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:51:1
+  --> $DIR/debug.rs:50:1
    |
 LL | type TestAbiNeSign = (fn(i32), fn(u32));
    | ^^^^^^^^^^^^^^^^^^
 
 error[E0277]: the size for values of type `str` cannot be known at compilation time
-  --> $DIR/debug.rs:54:46
+  --> $DIR/debug.rs:53:46
    |
 LL | type TestAbiEqNonsense = (fn((str, str)), fn((str, str)));
    |                                              ^^^^^^^^^^ doesn't have a size known at compile-time
@@ -861,7 +861,7 @@ LL | type TestAbiEqNonsense = (fn((str, str)), fn((str, str)));
    = note: only the last element of a tuple may have a dynamically sized type
 
 error: `#[rustc_abi]` can only be applied to function items, type aliases, and associated functions
-  --> $DIR/debug.rs:29:5
+  --> $DIR/debug.rs:28:5
    |
 LL |     const C: () = ();
    |     ^^^^^^^^^^^
@@ -870,7 +870,7 @@ error: fn_abi_of(assoc_test) = FnAbi {
            args: [
                ArgAbi {
                    layout: TyAndLayout {
-                       ty: &ReErased Adt(S, []),
+                       ty: &S,
                        layout: Layout {
                            size: $SOME_SIZE,
                            align: AbiAndPrefAlign {
@@ -949,7 +949,7 @@ error: fn_abi_of(assoc_test) = FnAbi {
            conv: Rust,
            can_unwind: $SOME_BOOL,
        }
-  --> $DIR/debug.rs:34:5
+  --> $DIR/debug.rs:33:5
    |
 LL |     fn assoc_test(&self) { }
    |     ^^^^^^^^^^^^^^^^^^^^