Mark all diagnostic structs with #[must_use]

To prevent bugs like 118972.

Author: Enselic

compiler/rustc_ast_lowering/src/errors.rs

@@ -4,6 +4,7 @@ use rustc_span::{symbol::Ident, Span, Symbol};
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_generic_type_with_parentheses, code = "E0214")]
+#[must_use]
 pub struct GenericTypeWithParentheses {
     #[primary_span]
     #[label]
@@ -24,6 +25,7 @@ pub struct UseAngleBrackets {
 #[derive(Diagnostic)]
 #[diag(ast_lowering_invalid_abi, code = "E0703")]
 #[note]
+#[must_use]
 pub struct InvalidAbi {
     #[primary_span]
     #[label]
@@ -65,6 +67,7 @@ pub struct InvalidAbiSuggestion {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_assoc_ty_parentheses)]
+#[must_use]
 pub struct AssocTyParentheses {
     #[primary_span]
     pub span: Span,
@@ -90,6 +93,7 @@ pub enum AssocTyParenthesesSub {
 
 #[derive(Diagnostic)]
 #[diag(ast_lowering_misplaced_impl_trait, code = "E0562")]
+#[must_use]
 pub struct MisplacedImplTrait<'a> {
     #[primary_span]
     pub span: Span,
@@ -98,6 +102,7 @@ pub struct MisplacedImplTrait<'a> {
 
 #[derive(Diagnostic)]
 #[diag(ast_lowering_misplaced_assoc_ty_binding)]
+#[must_use]
 pub struct MisplacedAssocTyBinding<'a> {
     #[primary_span]
     pub span: Span,
@@ -106,6 +111,7 @@ pub struct MisplacedAssocTyBinding<'a> {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_underscore_expr_lhs_assign)]
+#[must_use]
 pub struct UnderscoreExprLhsAssign {
     #[primary_span]
     #[label]
@@ -114,6 +120,7 @@ pub struct UnderscoreExprLhsAssign {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_base_expression_double_dot)]
+#[must_use]
 pub struct BaseExpressionDoubleDot {
     #[primary_span]
     #[label]
@@ -122,6 +129,7 @@ pub struct BaseExpressionDoubleDot {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_await_only_in_async_fn_and_blocks, code = "E0728")]
+#[must_use]
 pub struct AwaitOnlyInAsyncFnAndBlocks {
     #[primary_span]
     #[label]
@@ -132,13 +140,15 @@ pub struct AwaitOnlyInAsyncFnAndBlocks {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_coroutine_too_many_parameters, code = "E0628")]
+#[must_use]
 pub struct CoroutineTooManyParameters {
     #[primary_span]
     pub fn_decl_span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_closure_cannot_be_static, code = "E0697")]
+#[must_use]
 pub struct ClosureCannotBeStatic {
     #[primary_span]
     pub fn_decl_span: Span,
@@ -147,13 +157,15 @@ pub struct ClosureCannotBeStatic {
 #[derive(Diagnostic, Clone, Copy)]
 #[help]
 #[diag(ast_lowering_async_non_move_closure_not_supported, code = "E0708")]
+#[must_use]
 pub struct AsyncNonMoveClosureNotSupported {
     #[primary_span]
     pub fn_decl_span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_functional_record_update_destructuring_assignment)]
+#[must_use]
 pub struct FunctionalRecordUpdateDestructuringAssignment {
     #[primary_span]
     #[suggestion(code = "", applicability = "machine-applicable")]
@@ -162,27 +174,31 @@ pub struct FunctionalRecordUpdateDestructuringAssignment {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_async_coroutines_not_supported, code = "E0727")]
+#[must_use]
 pub struct AsyncCoroutinesNotSupported {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_inline_asm_unsupported_target, code = "E0472")]
+#[must_use]
 pub struct InlineAsmUnsupportedTarget {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_att_syntax_only_x86)]
+#[must_use]
 pub struct AttSyntaxOnlyX86 {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_abi_specified_multiple_times)]
+#[must_use]
 pub struct AbiSpecifiedMultipleTimes {
     #[primary_span]
     pub abi_span: Span,
@@ -195,6 +211,7 @@ pub struct AbiSpecifiedMultipleTimes {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_clobber_abi_not_supported)]
+#[must_use]
 pub struct ClobberAbiNotSupported {
     #[primary_span]
     pub abi_span: Span,
@@ -203,6 +220,7 @@ pub struct ClobberAbiNotSupported {
 #[derive(Diagnostic)]
 #[note]
 #[diag(ast_lowering_invalid_abi_clobber_abi)]
+#[must_use]
 pub struct InvalidAbiClobberAbi {
     #[primary_span]
     pub abi_span: Span,
@@ -211,6 +229,7 @@ pub struct InvalidAbiClobberAbi {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_invalid_register)]
+#[must_use]
 pub struct InvalidRegister<'a> {
     #[primary_span]
     pub op_span: Span,
@@ -220,6 +239,7 @@ pub struct InvalidRegister<'a> {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_invalid_register_class)]
+#[must_use]
 pub struct InvalidRegisterClass<'a> {
     #[primary_span]
     pub op_span: Span,
@@ -229,6 +249,7 @@ pub struct InvalidRegisterClass<'a> {
 
 #[derive(Diagnostic)]
 #[diag(ast_lowering_invalid_asm_template_modifier_reg_class)]
+#[must_use]
 pub struct InvalidAsmTemplateModifierRegClass {
     #[primary_span]
     #[label(ast_lowering_template_modifier)]
@@ -249,6 +270,7 @@ pub enum InvalidAsmTemplateModifierRegClassSub {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_invalid_asm_template_modifier_const)]
+#[must_use]
 pub struct InvalidAsmTemplateModifierConst {
     #[primary_span]
     #[label(ast_lowering_template_modifier)]
@@ -259,6 +281,7 @@ pub struct InvalidAsmTemplateModifierConst {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_invalid_asm_template_modifier_sym)]
+#[must_use]
 pub struct InvalidAsmTemplateModifierSym {
     #[primary_span]
     #[label(ast_lowering_template_modifier)]
@@ -269,6 +292,7 @@ pub struct InvalidAsmTemplateModifierSym {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_register_class_only_clobber)]
+#[must_use]
 pub struct RegisterClassOnlyClobber {
     #[primary_span]
     pub op_span: Span,
@@ -277,6 +301,7 @@ pub struct RegisterClassOnlyClobber {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_register_conflict)]
+#[must_use]
 pub struct RegisterConflict<'a> {
     #[primary_span]
     #[label(ast_lowering_register1)]
@@ -292,6 +317,7 @@ pub struct RegisterConflict<'a> {
 #[derive(Diagnostic, Clone, Copy)]
 #[help]
 #[diag(ast_lowering_sub_tuple_binding)]
+#[must_use]
 pub struct SubTupleBinding<'a> {
     #[primary_span]
     #[label]
@@ -309,6 +335,7 @@ pub struct SubTupleBinding<'a> {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_extra_double_dot)]
+#[must_use]
 pub struct ExtraDoubleDot<'a> {
     #[primary_span]
     #[label]
@@ -321,27 +348,31 @@ pub struct ExtraDoubleDot<'a> {
 #[derive(Diagnostic, Clone, Copy)]
 #[note]
 #[diag(ast_lowering_misplaced_double_dot)]
+#[must_use]
 pub struct MisplacedDoubleDot {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_misplaced_relax_trait_bound)]
+#[must_use]
 pub struct MisplacedRelaxTraitBound {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_not_supported_for_lifetime_binder_async_closure)]
+#[must_use]
 pub struct NotSupportedForLifetimeBinderAsyncClosure {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic)]
 #[diag(ast_lowering_match_arm_with_no_body)]
+#[must_use]
 pub struct MatchArmWithNoBody {
     #[primary_span]
     pub span: Span,
@@ -351,6 +382,7 @@ pub struct MatchArmWithNoBody {
 
 #[derive(Diagnostic)]
 #[diag(ast_lowering_never_pattern_with_body)]
+#[must_use]
 pub struct NeverPatternWithBody {
     #[primary_span]
     #[label]
@@ -360,6 +392,7 @@ pub struct NeverPatternWithBody {
 
 #[derive(Diagnostic)]
 #[diag(ast_lowering_never_pattern_with_guard)]
+#[must_use]
 pub struct NeverPatternWithGuard {
     #[primary_span]
     #[suggestion(code = "", applicability = "maybe-incorrect")]
@@ -368,13 +401,15 @@ pub struct NeverPatternWithGuard {
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_arbitrary_expression_in_pattern)]
+#[must_use]
 pub struct ArbitraryExpressionInPattern {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(Diagnostic, Clone, Copy)]
 #[diag(ast_lowering_inclusive_range_with_no_end)]
+#[must_use]
 pub struct InclusiveRangeWithNoEnd {
     #[primary_span]
     pub span: Span,