Rollup merge of #134949 - compiler-errors:froms, r=jieyouxu

Convert some `Into` impls into `From` impls

From the [`From`](https://doc.rust-lang.org/std/convert/trait.From.html) docs:

> One should always prefer implementing `From` over [`Into`](https://doc.rust-lang.org/std/convert/trait.Into.html) because implementing `From` automatically provides one with an implementation of [`Into`](https://doc.rust-lang.org/std/convert/trait.Into.html) thanks to the blanket implementation in the standard library.
>
> Only implement [`Into`](https://doc.rust-lang.org/std/convert/trait.Into.html) when targeting a version prior to Rust 1.41 and converting to a type outside the current crate. `From` was not able to do these types of conversions in earlier versions because of Rust’s orphaning rules. See [Into](https://doc.rust-lang.org/std/convert/trait.Into.html) for more details.

Some of these impls are likely from before 1.41, and then some others were probably just mistakes. Building nightly rust is definitely not supported on 1.41, so let's modernize these impls :D

9 files changed, 45 insertions, 45 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 31e6750a678..3a81b93d157 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -241,15 +241,15 @@ impl AngleBracketedArg {
     }
 }
 
-impl Into<P<GenericArgs>> for AngleBracketedArgs {
-    fn into(self) -> P<GenericArgs> {
-        P(GenericArgs::AngleBracketed(self))
+impl From<AngleBracketedArgs> for P<GenericArgs> {
+    fn from(val: AngleBracketedArgs) -> Self {
+        P(GenericArgs::AngleBracketed(val))
     }
 }
 
-impl Into<P<GenericArgs>> for ParenthesizedArgs {
-    fn into(self) -> P<GenericArgs> {
-        P(GenericArgs::Parenthesized(self))
+impl From<ParenthesizedArgs> for P<GenericArgs> {
+    fn from(val: ParenthesizedArgs) -> Self {
+        P(GenericArgs::Parenthesized(val))
     }
 }
 
diff --git a/compiler/rustc_ast/src/ptr.rs b/compiler/rustc_ast/src/ptr.rs
index 97c714df8fd..dd923305cdf 100644
--- a/compiler/rustc_ast/src/ptr.rs
+++ b/compiler/rustc_ast/src/ptr.rs
@@ -158,9 +158,9 @@ impl<T> From<Vec<T>> for P<[T]> {
     }
 }
 
-impl<T> Into<Vec<T>> for P<[T]> {
-    fn into(self) -> Vec<T> {
-        self.into_vec()
+impl<T> From<P<[T]>> for Vec<T> {
+    fn from(val: P<[T]>) -> Self {
+        val.into_vec()
     }
 }
 
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index 74b6d63365a..a51c4140e17 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -357,9 +357,9 @@ impl From<Cow<'static, str>> for DiagMessage {
 /// subdiagnostic derive refers to typed identifiers that are `DiagMessage`s, so need to be
 /// able to convert between these, as much as they'll be converted back into `DiagMessage`
 /// using `with_subdiagnostic_message` eventually. Don't use this other than for the derive.
-impl Into<SubdiagMessage> for DiagMessage {
-    fn into(self) -> SubdiagMessage {
-        match self {
+impl From<DiagMessage> for SubdiagMessage {
+    fn from(val: DiagMessage) -> Self {
+        match val {
             DiagMessage::Str(s) => SubdiagMessage::Str(s),
             DiagMessage::Translated(s) => SubdiagMessage::Translated(s),
             DiagMessage::FluentIdentifier(id, None) => SubdiagMessage::FluentIdentifier(id),
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 05b9cbfbc06..afce877547f 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -156,9 +156,9 @@ impl IntoDiagArg for DiagArgValue {
     }
 }
 
-impl Into<FluentValue<'static>> for DiagArgValue {
-    fn into(self) -> FluentValue<'static> {
-        match self {
+impl From<DiagArgValue> for FluentValue<'static> {
+    fn from(val: DiagArgValue) -> Self {
+        match val {
             DiagArgValue::Str(s) => From::from(s),
             DiagArgValue::Number(n) => From::from(n),
             DiagArgValue::StrListSepByAnd(l) => fluent_value_from_str_list_sep_by_and(l),
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 8cea269f298..5ea3bcef9ba 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -4072,33 +4072,33 @@ impl<'hir> OwnerNode<'hir> {
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir Item<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::Item(self)
+impl<'hir> From<&'hir Item<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir Item<'hir>) -> Self {
+        OwnerNode::Item(val)
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir ForeignItem<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::ForeignItem(self)
+impl<'hir> From<&'hir ForeignItem<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir ForeignItem<'hir>) -> Self {
+        OwnerNode::ForeignItem(val)
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir ImplItem<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::ImplItem(self)
+impl<'hir> From<&'hir ImplItem<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir ImplItem<'hir>) -> Self {
+        OwnerNode::ImplItem(val)
     }
 }
 
-impl<'hir> Into<OwnerNode<'hir>> for &'hir TraitItem<'hir> {
-    fn into(self) -> OwnerNode<'hir> {
-        OwnerNode::TraitItem(self)
+impl<'hir> From<&'hir TraitItem<'hir>> for OwnerNode<'hir> {
+    fn from(val: &'hir TraitItem<'hir>) -> Self {
+        OwnerNode::TraitItem(val)
     }
 }
 
-impl<'hir> Into<Node<'hir>> for OwnerNode<'hir> {
-    fn into(self) -> Node<'hir> {
-        match self {
+impl<'hir> From<OwnerNode<'hir>> for Node<'hir> {
+    fn from(val: OwnerNode<'hir>) -> Self {
+        match val {
             OwnerNode::Item(n) => Node::Item(n),
             OwnerNode::ForeignItem(n) => Node::ForeignItem(n),
             OwnerNode::ImplItem(n) => Node::ImplItem(n),
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index 64a1c70dd2f..4fe8f73efd6 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -303,9 +303,9 @@ pub(crate) struct RawDefId {
     index: u32,
 }
 
-impl Into<RawDefId> for DefId {
-    fn into(self) -> RawDefId {
-        RawDefId { krate: self.krate.as_u32(), index: self.index.as_u32() }
+impl From<DefId> for RawDefId {
+    fn from(val: DefId) -> Self {
+        RawDefId { krate: val.krate.as_u32(), index: val.index.as_u32() }
     }
 }
 
diff --git a/compiler/rustc_middle/src/mir/interpret/error.rs b/compiler/rustc_middle/src/mir/interpret/error.rs
index 37328470aa7..8c085fa310a 100644
--- a/compiler/rustc_middle/src/mir/interpret/error.rs
+++ b/compiler/rustc_middle/src/mir/interpret/error.rs
@@ -88,10 +88,10 @@ impl ReportedErrorInfo {
     }
 }
 
-impl Into<ErrorGuaranteed> for ReportedErrorInfo {
+impl From<ReportedErrorInfo> for ErrorGuaranteed {
     #[inline]
-    fn into(self) -> ErrorGuaranteed {
-        self.error
+    fn from(val: ReportedErrorInfo) -> Self {
+        val.error
     }
 }
 
diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs
index 8f4137cc011..e28fcc555dc 100644
--- a/compiler/rustc_middle/src/ty/adt.rs
+++ b/compiler/rustc_middle/src/ty/adt.rs
@@ -249,9 +249,9 @@ pub enum AdtKind {
     Enum,
 }
 
-impl Into<DataTypeKind> for AdtKind {
-    fn into(self) -> DataTypeKind {
-        match self {
+impl From<AdtKind> for DataTypeKind {
+    fn from(val: AdtKind) -> Self {
+        match val {
             AdtKind::Struct => DataTypeKind::Struct,
             AdtKind::Union => DataTypeKind::Union,
             AdtKind::Enum => DataTypeKind::Enum,
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
index 2dcf3760d2f..68a53381230 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
@@ -45,12 +45,12 @@ pub enum TypeAnnotationNeeded {
     E0284,
 }
 
-impl Into<ErrCode> for TypeAnnotationNeeded {
-    fn into(self) -> ErrCode {
-        match self {
-            Self::E0282 => E0282,
-            Self::E0283 => E0283,
-            Self::E0284 => E0284,
+impl From<TypeAnnotationNeeded> for ErrCode {
+    fn from(val: TypeAnnotationNeeded) -> Self {
+        match val {
+            TypeAnnotationNeeded::E0282 => E0282,
+            TypeAnnotationNeeded::E0283 => E0283,
+            TypeAnnotationNeeded::E0284 => E0284,
         }
     }
 }