FIR: Self types draft

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -975,6 +975,13 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.SELF_TYPE_INAPPLICABLE_TARGET) { firDiagnostic ->
+        SelfTypeInapplicableTargetImpl(
+            firDiagnostic.a,
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.OPT_IN_USAGE) { firDiagnostic ->
         OptInUsageImpl(
             firDiagnostic.a,
@@ -2091,6 +2098,12 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.SELF_TYPE_PARAMETER_FOR_CLASS_WITH_SELF_TYPE) { firDiagnostic ->
+        SelfTypeParameterForClassWithSelfTypeImpl(
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.EXTENSION_IN_CLASS_REFERENCE_NOT_ALLOWED) { firDiagnostic ->
         ExtensionInClassReferenceNotAllowedImpl(
             firSymbolBuilder.callableBuilder.buildCallableSymbol(firDiagnostic.a),

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -703,6 +703,11 @@ sealed class KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         abstract val typeFromTypesPhase: KtType
     }
 
+    abstract class SelfTypeInapplicableTarget : KtFirDiagnostic<KtAnnotationEntry>() {
+        override val diagnosticClass get() = SelfTypeInapplicableTarget::class
+        abstract val actualTarget: String
+    }
+
     abstract class OptInUsage : KtFirDiagnostic<PsiElement>() {
         override val diagnosticClass get() = OptInUsage::class
         abstract val optInMarkerFqName: FqName
@@ -1487,6 +1492,10 @@ sealed class KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = NullableOnDefinitelyNotNullable::class
     }
 
+    abstract class SelfTypeParameterForClassWithSelfType : KtFirDiagnostic<KtTypeParameter>() {
+        override val diagnosticClass get() = SelfTypeParameterForClassWithSelfType::class
+    }
+
     abstract class ExtensionInClassReferenceNotAllowed : KtFirDiagnostic<KtExpression>() {
         override val diagnosticClass get() = ExtensionInClassReferenceNotAllowed::class
         abstract val referencedDeclaration: KtCallableSymbol

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -844,6 +844,12 @@ internal class PluginAnnotationAmbiguityImpl(
     override val token: KtLifetimeToken,
 ) : KtFirDiagnostic.PluginAnnotationAmbiguity(), KtAbstractFirDiagnostic<PsiElement>
 
+internal class SelfTypeInapplicableTargetImpl(
+    override val actualTarget: String,
+    override val firDiagnostic: KtPsiDiagnostic,
+    override val token: KtLifetimeToken,
+) : KtFirDiagnostic.SelfTypeInapplicableTarget(), KtAbstractFirDiagnostic<KtAnnotationEntry>
+
 internal class OptInUsageImpl(
     override val optInMarkerFqName: FqName,
     override val message: String,
@@ -1786,6 +1792,11 @@ internal class NullableOnDefinitelyNotNullableImpl(
     override val token: KtLifetimeToken,
 ) : KtFirDiagnostic.NullableOnDefinitelyNotNullable(), KtAbstractFirDiagnostic<KtTypeReference>
 
+internal class SelfTypeParameterForClassWithSelfTypeImpl(
+    override val firDiagnostic: KtPsiDiagnostic,
+    override val token: KtLifetimeToken,
+) : KtFirDiagnostic.SelfTypeParameterForClassWithSelfType(), KtAbstractFirDiagnostic<KtTypeParameter>
+
 internal class ExtensionInClassReferenceNotAllowedImpl(
     override val referencedDeclaration: KtCallableSymbol,
     override val firDiagnostic: KtPsiDiagnostic,

compiler/fir/analysis-tests/testData/resolve/cfg/selfTypes/basic.fir.txt

@@ -0,0 +1,63 @@
+FILE: basic.kt
+    @R|kotlin/Self|() public final class JustSelfAnnotation<out <Self> : R|JustSelfAnnotation<<Self>>|> : R|kotlin/Any| {
+        public constructor<out <Self> : R|JustSelfAnnotation<<Self>>|>(): R|JustSelfAnnotation<<Self>>| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun anyFun(): R|kotlin/String| {
+            ^anyFun String(string)
+        }
+
+    }
+    @R|kotlin/Self|() public final class ReturnType<out <Self> : R|ReturnType<<Self>>|> : R|kotlin/Any| {
+        public constructor<out <Self> : R|ReturnType<<Self>>|>(): R|ReturnType<<Self>>| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun returnTypeWithVal(): R|<Self>| {
+            lval res: R|<Self>| = this@R|/ReturnType|
+            ^returnTypeWithVal R|<local>/res|
+        }
+
+    }
+    @R|kotlin/Self|() public final class SelfWithSelfVariable<out <Self> : R|SelfWithSelfVariable<<Self>>|> : R|kotlin/Any| {
+        public constructor<out <Self> : R|SelfWithSelfVariable<<Self>>|>(): R|SelfWithSelfVariable<<Self>>| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun returnType(): R|<Self>| {
+            lval Self: R|<Self>| = this@R|/SelfWithSelfVariable|
+            ^returnType R|<local>/Self|
+        }
+
+    }
+    @R|kotlin/Self|() public final class SelfTypeWithSelfFunction<out <Self> : R|SelfTypeWithSelfFunction<<Self>>|> : R|kotlin/Any| {
+        public constructor<out <Self> : R|SelfTypeWithSelfFunction<<Self>>|>(): R|SelfTypeWithSelfFunction<<Self>>| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun Self(): R|<Self>| {
+            ^Self this@R|/SelfTypeWithSelfFunction|
+        }
+
+    }
+    @R|kotlin/Self|() public final class SelfWithFunctionReturningItself<out <Self> : R|SelfWithFunctionReturningItself<<Self>>|> : R|kotlin/Any| {
+        public constructor<out <Self> : R|SelfWithFunctionReturningItself<<Self>>|>(): R|SelfWithFunctionReturningItself<<Self>>| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun ret(): R|SelfWithFunctionReturningItself<*>| {
+            ^ret this@R|/SelfWithFunctionReturningItself|
+        }
+
+    }
+    @R|kotlin/Self|() public final class SelfWithFunctionReturningItselfAndTypeParameter<T, out <Self> : R|SelfWithFunctionReturningItselfAndTypeParameter<T, <Self>>|> : R|kotlin/Any| {
+        public constructor<T, out <Self> : R|SelfWithFunctionReturningItselfAndTypeParameter<T, <Self>>|>(): R|SelfWithFunctionReturningItselfAndTypeParameter<T, <Self>>| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun ret(): R|SelfWithFunctionReturningItselfAndTypeParameter<T, *>| {
+            ^ret this@R|/SelfWithFunctionReturningItselfAndTypeParameter|
+        }
+
+    }

compiler/fir/analysis-tests/testData/resolve/cfg/selfTypes/basic.kt

@@ -0,0 +1,44 @@
+// FIR_DISABLE_LAZY_RESOLVE_CHECKS
+import kotlin.Self
+
+@Self
+class JustSelfAnnotation {
+    fun anyFun(): String = "string"
+}
+
+@Self
+class ReturnType {
+    fun returnTypeWithVal(): Self {
+        val res: Self  = this
+        return res
+    }
+}
+
+@Self
+class SelfWithSelfVariable {
+    fun returnType(): Self {
+        val Self: Self = this
+        return Self
+    }
+}
+
+@Self
+class SelfTypeWithSelfFunction {
+    fun Self(): Self {
+        return this
+    }
+}
+
+@Self
+class SelfWithFunctionReturningItself {
+    fun ret(): SelfWithFunctionReturningItself {
+        return this
+    }
+}
+
+@Self
+class SelfWithFunctionReturningItselfAndTypeParameter<T> {
+    fun ret(): SelfWithFunctionReturningItselfAndTypeParameter<T> {
+        return this
+    }
+}