Auto merge of #101558 - JhonnyBillM:session-diagnostic-to-diagnostic-handler-refactor, r=davidtwco

Move and rename `SessionDiagnostic` & `SessionSubdiagnostic` traits and macros

After PR #101434, we want to:
- [x] Move `SessionDiagnostic` to `rustc_errors`.
- [x] Add `emit_` methods that accept `impl SessionDiagnostic` to `Handler`.
- [x] _(optional)_ Rename trait `SessionDiagnostic` to `DiagnosticHandler`.
- [x] _(optional)_ Rename macro `SessionDiagnostic` to `DiagnosticHandler`.
- [x] Update Rustc Dev Guide and Docs to reflect these changes. https://github.com/rust-lang/rustc-dev-guide/pull/1460

Now I am having build issues getting the compiler to build when trying to rename the macro.

<details>
  <summary>See diagnostics errors and context when building.</summary>

```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
  --> compiler/rustc_attr/src/session_diagnostics.rs:13:10
   |
13 |   #[derive(DiagnosticHandler)]
   |            ^^^^^^^^^^^^^^^^^ in this derive macro expansion
   |
  ::: /Users/jhonny/.cargo/registry/src/github.com-1ecc6299db9ec823/synstructure-0.12.6/src/macros.rs:94:9
   |
94 | /         pub fn $derives(
95 | |             i: $crate::macros::TokenStream
96 | |         ) -> $crate::macros::TokenStream {
   | |________________________________________- in this expansion of `#[derive(DiagnosticHandler)]`
   |
note: the lint level is defined here
  --> compiler/rustc_attr/src/lib.rs:10:9
   |
10 | #![deny(rustc::diagnostic_outside_of_impl)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

```

And also this one:

```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
   --> compiler/rustc_attr/src/session_diagnostics.rs:213:32
    |
213 |         let mut diag = handler.struct_span_err_with_code(
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^
```

> **Note**
> Can't find where this message is coming from, because you can see in [this experimental branch](https://github.com/JhonnyBillM/rust/tree/experimental/trying-to-rename-session-diagnostic-macro)  that I updated all errors and diags to say:
> error: diagnostics should only be created in **`DiagnosticHandler`**/`AddSubdiagnostic` impls
> and not:
> error: diagnostics should only be created in **`SessionDiagnostic`**/`AddSubdiagnostic` impls

</details>

I tried building the compiler in different ways (playing with the stages etc), but nothing worked.

## Question

**Do we need to build or do something different when renaming a macro and identifiers?**

For context, see experimental commit https://github.com/JhonnyBillM/rust/commit/f2193a98b44db3f2af77a878824b152cdf0d34a5 where the macro and symbols are renamed, but it doesn't compile.

2 files changed, 51 insertions, 51 deletions

diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index a65f523a0f4..dcea11eadcb 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -20,7 +20,7 @@ use rustc_errors::{
     fluent, Applicability, DiagnosticBuilder, DiagnosticMessage, Handler, MultiSpan, PResult,
 };
 use rustc_errors::{pluralize, struct_span_err, Diagnostic, ErrorGuaranteed};
-use rustc_macros::{SessionDiagnostic, SessionSubdiagnostic};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::{Span, SpanSnippetError, DUMMY_SP};
@@ -242,7 +242,7 @@ impl MultiSugg {
     }
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::maybe_report_ambiguous_plus)]
 struct AmbiguousPlus {
     pub sum_ty: String,
@@ -251,7 +251,7 @@ struct AmbiguousPlus {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::maybe_recover_from_bad_type_plus, code = "E0178")]
 struct BadTypePlus {
     pub ty: String,
@@ -261,7 +261,7 @@ struct BadTypePlus {
     pub sub: BadTypePlusSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum BadTypePlusSub {
     #[suggestion(
         parser::add_paren,
@@ -285,7 +285,7 @@ pub enum BadTypePlusSub {
     },
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::maybe_recover_from_bad_qpath_stage_2)]
 struct BadQPathStage2 {
     #[primary_span]
@@ -294,7 +294,7 @@ struct BadQPathStage2 {
     ty: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::incorrect_semicolon)]
 struct IncorrectSemicolon<'a> {
     #[primary_span]
@@ -305,7 +305,7 @@ struct IncorrectSemicolon<'a> {
     name: &'a str,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::incorrect_use_of_await)]
 struct IncorrectUseOfAwait {
     #[primary_span]
@@ -313,7 +313,7 @@ struct IncorrectUseOfAwait {
     span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::incorrect_use_of_await)]
 struct IncorrectAwait {
     #[primary_span]
@@ -324,7 +324,7 @@ struct IncorrectAwait {
     question_mark: &'static str,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::in_in_typo)]
 struct InInTypo {
     #[primary_span]
@@ -333,7 +333,7 @@ struct InInTypo {
     sugg_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_variable_declaration)]
 pub struct InvalidVariableDeclaration {
     #[primary_span]
@@ -342,7 +342,7 @@ pub struct InvalidVariableDeclaration {
     pub sub: InvalidVariableDeclarationSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum InvalidVariableDeclarationSub {
     #[suggestion(
         parser::switch_mut_let_order,
@@ -362,7 +362,7 @@ pub enum InvalidVariableDeclarationSub {
     UseLetNotVar(#[primary_span] Span),
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_comparison_operator)]
 pub(crate) struct InvalidComparisonOperator {
     #[primary_span]
@@ -372,7 +372,7 @@ pub(crate) struct InvalidComparisonOperator {
     pub sub: InvalidComparisonOperatorSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum InvalidComparisonOperatorSub {
     #[suggestion_short(
         parser::use_instead,
@@ -389,7 +389,7 @@ pub(crate) enum InvalidComparisonOperatorSub {
     Spaceship(#[primary_span] Span),
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_logical_operator)]
 #[note]
 pub(crate) struct InvalidLogicalOperator {
@@ -400,7 +400,7 @@ pub(crate) struct InvalidLogicalOperator {
     pub sub: InvalidLogicalOperatorSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum InvalidLogicalOperatorSub {
     #[suggestion_short(
         parser::use_amp_amp_for_conjunction,
@@ -416,7 +416,7 @@ pub(crate) enum InvalidLogicalOperatorSub {
     Disjunction(#[primary_span] Span),
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::tilde_is_not_unary_operator)]
 pub(crate) struct TildeAsUnaryOperator(
     #[primary_span]
@@ -424,7 +424,7 @@ pub(crate) struct TildeAsUnaryOperator(
     pub Span,
 );
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::unexpected_token_after_not)]
 pub(crate) struct NotAsNegationOperator {
     #[primary_span]
@@ -434,7 +434,7 @@ pub(crate) struct NotAsNegationOperator {
     pub sub: NotAsNegationOperatorSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub enum NotAsNegationOperatorSub {
     #[suggestion_short(
         parser::unexpected_token_after_not_default,
@@ -458,7 +458,7 @@ pub enum NotAsNegationOperatorSub {
     SuggestNotLogical(#[primary_span] Span),
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::malformed_loop_label)]
 pub(crate) struct MalformedLoopLabel {
     #[primary_span]
@@ -467,7 +467,7 @@ pub(crate) struct MalformedLoopLabel {
     pub correct_label: Ident,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::lifetime_in_borrow_expression)]
 pub(crate) struct LifetimeInBorrowExpression {
     #[primary_span]
@@ -477,15 +477,15 @@ pub(crate) struct LifetimeInBorrowExpression {
     pub lifetime_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::field_expression_with_generic)]
 pub(crate) struct FieldExpressionWithGeneric(#[primary_span] pub Span);
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::macro_invocation_with_qualified_path)]
 pub(crate) struct MacroInvocationWithQualifiedPath(#[primary_span] pub Span);
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::unexpected_token_after_label)]
 pub(crate) struct UnexpectedTokenAfterLabel(
     #[primary_span]
@@ -493,7 +493,7 @@ pub(crate) struct UnexpectedTokenAfterLabel(
     pub Span,
 );
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::require_colon_after_labeled_expression)]
 #[note]
 pub(crate) struct RequireColonAfterLabeledExpression {
@@ -505,7 +505,7 @@ pub(crate) struct RequireColonAfterLabeledExpression {
     pub label_end: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::do_catch_syntax_removed)]
 #[note]
 pub(crate) struct DoCatchSyntaxRemoved {
@@ -514,7 +514,7 @@ pub(crate) struct DoCatchSyntaxRemoved {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::float_literal_requires_integer_part)]
 pub(crate) struct FloatLiteralRequiresIntegerPart {
     #[primary_span]
@@ -523,7 +523,7 @@ pub(crate) struct FloatLiteralRequiresIntegerPart {
     pub correct: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_int_literal_width)]
 #[help]
 pub(crate) struct InvalidIntLiteralWidth {
@@ -532,7 +532,7 @@ pub(crate) struct InvalidIntLiteralWidth {
     pub width: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_num_literal_base_prefix)]
 #[note]
 pub(crate) struct InvalidNumLiteralBasePrefix {
@@ -542,7 +542,7 @@ pub(crate) struct InvalidNumLiteralBasePrefix {
     pub fixed: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_num_literal_suffix)]
 #[help]
 pub(crate) struct InvalidNumLiteralSuffix {
@@ -552,7 +552,7 @@ pub(crate) struct InvalidNumLiteralSuffix {
     pub suffix: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_float_literal_width)]
 #[help]
 pub(crate) struct InvalidFloatLiteralWidth {
@@ -561,7 +561,7 @@ pub(crate) struct InvalidFloatLiteralWidth {
     pub width: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_float_literal_suffix)]
 #[help]
 pub(crate) struct InvalidFloatLiteralSuffix {
@@ -571,14 +571,14 @@ pub(crate) struct InvalidFloatLiteralSuffix {
     pub suffix: String,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::int_literal_too_large)]
 pub(crate) struct IntLiteralTooLarge {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::missing_semicolon_before_array)]
 pub(crate) struct MissingSemicolonBeforeArray {
     #[primary_span]
@@ -587,7 +587,7 @@ pub(crate) struct MissingSemicolonBeforeArray {
     pub semicolon: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::invalid_block_macro_segment)]
 pub(crate) struct InvalidBlockMacroSegment {
     #[primary_span]
@@ -596,7 +596,7 @@ pub(crate) struct InvalidBlockMacroSegment {
     pub context: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::if_expression_missing_then_block)]
 pub(crate) struct IfExpressionMissingThenBlock {
     #[primary_span]
@@ -605,7 +605,7 @@ pub(crate) struct IfExpressionMissingThenBlock {
     pub sub: IfExpressionMissingThenBlockSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum IfExpressionMissingThenBlockSub {
     #[help(parser::condition_possibly_unfinished)]
     UnfinishedCondition(#[primary_span] Span),
@@ -613,7 +613,7 @@ pub(crate) enum IfExpressionMissingThenBlockSub {
     AddThenBlock(#[primary_span] Span),
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::if_expression_missing_condition)]
 pub(crate) struct IfExpressionMissingCondition {
     #[primary_span]
@@ -623,14 +623,14 @@ pub(crate) struct IfExpressionMissingCondition {
     pub block_span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::expected_expression_found_let)]
 pub(crate) struct ExpectedExpressionFoundLet {
     #[primary_span]
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::expected_else_block)]
 pub(crate) struct ExpectedElseBlock {
     #[primary_span]
@@ -642,7 +642,7 @@ pub(crate) struct ExpectedElseBlock {
     pub condition_start: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::outer_attribute_not_allowed_on_if_else)]
 pub(crate) struct OuterAttributeNotAllowedOnIfElse {
     #[primary_span]
@@ -659,7 +659,7 @@ pub(crate) struct OuterAttributeNotAllowedOnIfElse {
     pub attributes: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::missing_in_in_for_loop)]
 pub(crate) struct MissingInInForLoop {
     #[primary_span]
@@ -668,7 +668,7 @@ pub(crate) struct MissingInInForLoop {
     pub sub: MissingInInForLoopSub,
 }
 
-#[derive(SessionSubdiagnostic)]
+#[derive(Subdiagnostic)]
 pub(crate) enum MissingInInForLoopSub {
     // Has been misleading, at least in the past (closed Issue #48492), thus maybe-incorrect
     #[suggestion_short(parser::use_in_not_of, applicability = "maybe-incorrect", code = "in")]
@@ -677,7 +677,7 @@ pub(crate) enum MissingInInForLoopSub {
     AddIn(#[primary_span] Span),
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::missing_comma_after_match_arm)]
 pub(crate) struct MissingCommaAfterMatchArm {
     #[primary_span]
@@ -685,7 +685,7 @@ pub(crate) struct MissingCommaAfterMatchArm {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::catch_after_try)]
 #[help]
 pub(crate) struct CatchAfterTry {
@@ -693,7 +693,7 @@ pub(crate) struct CatchAfterTry {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::comma_after_base_struct)]
 #[note]
 pub(crate) struct CommaAfterBaseStruct {
@@ -703,7 +703,7 @@ pub(crate) struct CommaAfterBaseStruct {
     pub comma: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::eq_field_init)]
 pub(crate) struct EqFieldInit {
     #[primary_span]
@@ -712,7 +712,7 @@ pub(crate) struct EqFieldInit {
     pub eq: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::dotdotdot)]
 pub(crate) struct DotDotDot {
     #[primary_span]
@@ -721,7 +721,7 @@ pub(crate) struct DotDotDot {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::left_arrow_operator)]
 pub(crate) struct LeftArrowOperator {
     #[primary_span]
@@ -729,7 +729,7 @@ pub(crate) struct LeftArrowOperator {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::remove_let)]
 pub(crate) struct RemoveLet {
     #[primary_span]
@@ -737,7 +737,7 @@ pub(crate) struct RemoveLet {
     pub span: Span,
 }
 
-#[derive(SessionDiagnostic)]
+#[derive(Diagnostic)]
 #[diag(parser::use_eq_instead)]
 pub(crate) struct UseEqInstead {
     #[primary_span]
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index f4f75f71e72..ae77961b7bc 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -36,10 +36,10 @@ use rustc_ast::{AnonConst, BinOp, BinOpKind, FnDecl, FnRetTy, MacCall, Param, Ty
 use rustc_ast::{Arm, Async, BlockCheckMode, Expr, ExprKind, Label, Movability, RangeLimits};
 use rustc_ast::{ClosureBinder, StmtKind};
 use rustc_ast_pretty::pprust;
+use rustc_errors::IntoDiagnostic;
 use rustc_errors::{Applicability, Diagnostic, PResult};
 use rustc_session::lint::builtin::BREAK_WITH_LABEL_AND_LOOP;
 use rustc_session::lint::BuiltinLintDiagnostics;
-use rustc_session::SessionDiagnostic;
 use rustc_span::source_map::{self, Span, Spanned};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{BytePos, Pos};