Rollup merge of #115866 - RalfJung:interpret-debug, r=compiler-errors

make interpreter and TyAndLayout type Debug impl independent of Ty debug impl

This fixes some (but not all) of the fallout from https://github.com/rust-lang/rust/pull/115661.

Second commit is taken from https://github.com/rust-lang/rust/pull/107084 (and slightly adjusted); I preserved the original git author information.

4 files changed, 55 insertions, 7 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs
index 8b33dbb677f..3d42fda1f68 100644
--- a/compiler/rustc_const_eval/src/interpret/operand.rs
+++ b/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()
     }
 }
 
diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs
index 90f2b470179..0f66df5c30d 100644
--- a/compiler/rustc_const_eval/src/interpret/place.rs
+++ b/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()
     }
 }
 
diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index 1a4a46ceb40..56547bfb426 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/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 {
diff --git a/compiler/rustc_target/src/abi/mod.rs b/compiler/rustc_target/src/abi/mod.rs
index a335585dbf3..636adcf6b17 100644
--- a/compiler/rustc_target/src/abi/mod.rs
+++ b/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 {