[FIR2IR] Fix cast insertion in SAM conversion with suspend conversion

#KT-65878
#KT-62855

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/AdapterGenerator.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.fir.backend.generators
 
+import org.jetbrains.kotlin.builtins.functions.isSuspendOrKSuspendFunction
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.backend.*
@@ -423,7 +424,7 @@ internal class AdapterGenerator(
                 castArgumentToFunctionalInterfaceForSamType(this, firSamConversion.expression.resolvedType, samFirType)
             )
 
-        return if (this is IrBlock && origin == IrStatementOrigin.ADAPTED_FUNCTION_REFERENCE) {
+        return if (this is IrBlock && (origin == IrStatementOrigin.ADAPTED_FUNCTION_REFERENCE || origin == IrStatementOrigin.SUSPEND_CONVERSION)) {
             // The IR for adapted callable references should be
             // BLOCK ADAPTED_FUNCTION_REFERENCE(FUN ADAPTER_FOR_CALLABLE_REFERENCE, TYPE_OP SAM_CONVERSION(FUNCTION_REFERENCE))
             // Therefore, we need to insert the cast as the last statement of the block, not around the block itself.
@@ -445,13 +446,21 @@ internal class AdapterGenerator(
     ): IrExpression {
         // The rule for SAM conversions is: the argument must be a subtype of the required function type.
         // We handle intersection types, captured types, etc. by approximating both expected and actual types.
-        val approximatedConeKotlinFunctionType = getFunctionTypeForPossibleSamType(samType)?.approximateForIrOrSelf() ?: return argument
+        var approximatedConeKotlinFunctionType = getFunctionTypeForPossibleSamType(samType)?.approximateForIrOrSelf() ?: return argument
 
         // This line is not present in the K1 counterpart because there is InsertImplicitCasts::cast that effectively removes
         // such unnecessary casts. At the same time, many IR lowerings assume that there are no such redundant casts and many
         // tests from FirBlackBoxCodegenTestGenerated relevant to INDY start failing once this line is removed.
         val approximateArgumentConeType = argumentConeType.approximateForIrOrSelf()
 
+        // We don't want to insert a redundant cast from a function type to a suspend function type,
+        // because that's already handled by suspend conversion.
+        if (approximatedConeKotlinFunctionType.functionTypeKind(session)?.isSuspendOrKSuspendFunction == true &&
+            approximateArgumentConeType.functionTypeKind(session)?.isSuspendOrKSuspendFunction != true
+        ) {
+            approximatedConeKotlinFunctionType = approximatedConeKotlinFunctionType.customFunctionTypeToSimpleFunctionType(session)
+        }
+
         if (approximateArgumentConeType.isSubtypeOf(approximatedConeKotlinFunctionType, session)) {
             return argument
         }

compiler/testData/codegen/box/sam/kt50477Enabled.jvm_abi.txt

@@ -1,73 +0,0 @@
-MODULE main
-	CLASS Kt50477EnabledKt$box$1.class
-		Property: class.signature
-			K1
-				NULL
-			K2
-				Lkotlin/jvm/internal/FunctionReferenceImpl;Lkotlin/jvm/functions/Function1<Lkotlin/coroutines/Continuation<-Lkotlin/Unit;>;Ljava/lang/Object;>;Lkotlin/coroutines/jvm/internal/SuspendFunction;
-		Property: class.superClassInternalName
-			K1
-				java/lang/Object
-			K2
-				kotlin/jvm/internal/FunctionReferenceImpl
-		Property: class.superInterfaces
-			K1
-				[FI, kotlin/jvm/internal/FunctionAdapter]
-			K2
-				[kotlin/coroutines/jvm/internal/SuspendFunction, kotlin/jvm/functions/Function1]
-		K1
-			call(Lkotlin/coroutines/Continuation;)Ljava/lang/Object; [public, final]
-		K2
-			---
-		K1
-			equals(Ljava/lang/Object;)Z [public, final]
-		K2
-			---
-		K1
-			getFunctionDelegate()Lkotlin/Function; [public, final]
-		K2
-			---
-		K1
-			hashCode()I [public, final]
-		K2
-			---
-		K1
-			---
-		K2
-			invoke(Lkotlin/coroutines/Continuation;)Ljava/lang/Object; [public, final]
-	CLASS Kt50477EnabledKt$box$4.class
-		Property: class.signature
-			K1
-				NULL
-			K2
-				Lkotlin/jvm/internal/FunctionReferenceImpl;Lkotlin/jvm/functions/Function1<Lkotlin/coroutines/Continuation<-Lkotlin/Unit;>;Ljava/lang/Object;>;Lkotlin/coroutines/jvm/internal/SuspendFunction;
-		Property: class.superClassInternalName
-			K1
-				java/lang/Object
-			K2
-				kotlin/jvm/internal/FunctionReferenceImpl
-		Property: class.superInterfaces
-			K1
-				[FI, kotlin/jvm/internal/FunctionAdapter]
-			K2
-				[kotlin/coroutines/jvm/internal/SuspendFunction, kotlin/jvm/functions/Function1]
-		K1
-			call(Lkotlin/coroutines/Continuation;)Ljava/lang/Object; [public, final]
-		K2
-			---
-		K1
-			equals(Ljava/lang/Object;)Z [public, final]
-		K2
-			---
-		K1
-			getFunctionDelegate()Lkotlin/Function; [public, final]
-		K2
-			---
-		K1
-			hashCode()I [public, final]
-		K2
-			---
-		K1
-			---
-		K2
-			invoke(Lkotlin/coroutines/Continuation;)Ljava/lang/Object; [public, final]

compiler/testData/codegen/box/sam/kt50477Enabled.kt

@@ -1,6 +1,5 @@
 // !LANGUAGE: +SuspendOnlySamConversions
 // TARGET_BACKEND: JVM_IR
-// JVM_ABI_K1_K2_DIFF: KT-62855
 
 fun interface FI {
     suspend fun call() // suspending now(!!!)

compiler/testData/codegen/box/suspendConversion/chainedFunSuspendConversionForSimpleExpression.jvm_abi.txt

@@ -1,31 +0,0 @@
-MODULE main
-	Missing in K1
-		ChainedFunSuspendConversionForSimpleExpressionKt$sam$SuspendRunnable$0.class
-	CLASS ChainedFunSuspendConversionForSimpleExpressionKt$test$2.class
-		Property: class.signature
-			K1
-				NULL
-			K2
-				Lkotlin/jvm/internal/FunctionReferenceImpl;Lkotlin/jvm/functions/Function1<Lkotlin/coroutines/Continuation<-Lkotlin/Unit;>;Ljava/lang/Object;>;Lkotlin/coroutines/jvm/internal/SuspendFunction;
-		Property: class.superClassInternalName
-			K1
-				java/lang/Object
-			K2
-				kotlin/jvm/internal/FunctionReferenceImpl
-		Property: class.superInterfaces
-			K1
-				[SuspendRunnable, kotlin/jvm/internal/FunctionAdapter]
-			K2
-				[kotlin/coroutines/jvm/internal/SuspendFunction, kotlin/jvm/functions/Function1]
-		K1
-			equals(Ljava/lang/Object;)Z [public, final]
-		K2
-			---
-		K1
-			getFunctionDelegate()Lkotlin/Function; [public, final]
-		K2
-			---
-		K1
-			hashCode()I [public, final]
-		K2
-			---

compiler/testData/codegen/box/suspendConversion/chainedFunSuspendConversionForSimpleExpression.kt

@@ -1,6 +1,5 @@
 // !LANGUAGE: +SuspendConversion
 // IGNORE_BACKEND: JVM
-// JVM_ABI_K1_K2_DIFF: KT-62855
 
 fun interface SuspendRunnable {
     suspend fun invoke()

compiler/testData/codegen/box/suspendConversion/suspendAndFunConversionInDisabledMode.jvm_abi.txt

@@ -2,6 +2,5 @@ MODULE main
 	Missing in K1
 		Test1$Scope$bar$1.class
 		Test2$Scope$bar$1.class
-		SuspendAndFunConversionInDisabledModeKt$sam$SuspendRunnable$0.class
 	Missing in K2
 		SuspendAndFunConversionInDisabledModeKt$sam$Runnable$0.class

compiler/testData/ir/irText/expressions/chainedFunSuspendConversionForSimpleExpression.fir.ir.txt

@@ -31,37 +31,34 @@ FILE fqName:<root> fileName:/chainedFunSuspendConversionForSimpleExpression.kt
     VALUE_PARAMETER name:f index:0 type:kotlin.Function0<kotlin.Unit>
     BLOCK_BODY
       CALL 'public final fun foo (s: <root>.SuspendRunnable): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        s: TYPE_OP type=<root>.SuspendRunnable origin=SAM_CONVERSION typeOperand=<root>.SuspendRunnable
+        s: BLOCK type=<root>.SuspendRunnable origin=SUSPEND_CONVERSION
-          TYPE_OP type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=IMPLICIT_CAST typeOperand=kotlin.coroutines.SuspendFunction0<kotlin.Unit>
+          FUN ADAPTER_FOR_SUSPEND_CONVERSION name:suspendConversion visibility:local modality:FINAL <> ($receiver:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit [suspend]
-            BLOCK type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION
+            $receiver: VALUE_PARAMETER ADAPTER_PARAMETER_FOR_SUSPEND_CONVERSION name:callee type:kotlin.Function0<kotlin.Unit>
-              FUN ADAPTER_FOR_SUSPEND_CONVERSION name:suspendConversion visibility:local modality:FINAL <> ($receiver:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit [suspend]
+            BLOCK_BODY
-                $receiver: VALUE_PARAMETER ADAPTER_PARAMETER_FOR_SUSPEND_CONVERSION name:callee type:kotlin.Function0<kotlin.Unit>
+              CALL 'public abstract fun invoke (): R of kotlin.Function0 declared in kotlin.Function0' type=kotlin.Unit origin=null
-                BLOCK_BODY
+                $this: GET_VAR 'callee: kotlin.Function0<kotlin.Unit> declared in <root>.test.suspendConversion' type=kotlin.Function0<kotlin.Unit> origin=null
-                  CALL 'public abstract fun invoke (): R of kotlin.Function0 declared in kotlin.Function0' type=kotlin.Unit origin=null
+          TYPE_OP type=<root>.SuspendRunnable origin=SAM_CONVERSION typeOperand=<root>.SuspendRunnable
-                    $this: GET_VAR 'callee: kotlin.Function0<kotlin.Unit> declared in <root>.test.suspendConversion' type=kotlin.Function0<kotlin.Unit> origin=null
+            FUNCTION_REFERENCE 'local final fun suspendConversion (): kotlin.Unit declared in <root>.test' type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION reflectionTarget=null
-              FUNCTION_REFERENCE 'local final fun suspendConversion (): kotlin.Unit declared in <root>.test' type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION reflectionTarget=null
+              $receiver: GET_VAR 'f: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null
-                $receiver: GET_VAR 'f: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null
       CALL 'public final fun foo (s: <root>.SuspendRunnable): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        s: TYPE_OP type=<root>.SuspendRunnable origin=SAM_CONVERSION typeOperand=<root>.SuspendRunnable
+        s: BLOCK type=<root>.SuspendRunnable origin=SUSPEND_CONVERSION
-          TYPE_OP type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=IMPLICIT_CAST typeOperand=kotlin.coroutines.SuspendFunction0<kotlin.Unit>
+          FUN ADAPTER_FOR_SUSPEND_CONVERSION name:suspendConversion visibility:local modality:FINAL <> ($receiver:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit [suspend]
-            BLOCK type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION
+            $receiver: VALUE_PARAMETER ADAPTER_PARAMETER_FOR_SUSPEND_CONVERSION name:callee type:kotlin.Function0<kotlin.Unit>
-              FUN ADAPTER_FOR_SUSPEND_CONVERSION name:suspendConversion visibility:local modality:FINAL <> ($receiver:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit [suspend]
+            BLOCK_BODY
-                $receiver: VALUE_PARAMETER ADAPTER_PARAMETER_FOR_SUSPEND_CONVERSION name:callee type:kotlin.Function0<kotlin.Unit>
+              CALL 'public abstract fun invoke (): R of kotlin.Function0 declared in kotlin.Function0' type=kotlin.Unit origin=null
-                BLOCK_BODY
+                $this: GET_VAR 'callee: kotlin.Function0<kotlin.Unit> declared in <root>.test.suspendConversion' type=kotlin.Function0<kotlin.Unit> origin=null
-                  CALL 'public abstract fun invoke (): R of kotlin.Function0 declared in kotlin.Function0' type=kotlin.Unit origin=null
+          TYPE_OP type=<root>.SuspendRunnable origin=SAM_CONVERSION typeOperand=<root>.SuspendRunnable
-                    $this: GET_VAR 'callee: kotlin.Function0<kotlin.Unit> declared in <root>.test.suspendConversion' type=kotlin.Function0<kotlin.Unit> origin=null
+            FUNCTION_REFERENCE 'local final fun suspendConversion (): kotlin.Unit declared in <root>.test' type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION reflectionTarget=null
-              FUNCTION_REFERENCE 'local final fun suspendConversion (): kotlin.Unit declared in <root>.test' type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION reflectionTarget=null
+              $receiver: CALL 'public final fun bar (): kotlin.Function0<kotlin.Unit> declared in <root>' type=kotlin.Function0<kotlin.Unit> origin=null
-                $receiver: CALL 'public final fun bar (): kotlin.Function0<kotlin.Unit> declared in <root>' type=kotlin.Function0<kotlin.Unit> origin=null
       VAR name:t type:kotlin.Function0<kotlin.Unit> [var]
         GET_VAR 'f: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null
       CALL 'public final fun foo (s: <root>.SuspendRunnable): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        s: TYPE_OP type=<root>.SuspendRunnable origin=SAM_CONVERSION typeOperand=<root>.SuspendRunnable
+        s: BLOCK type=<root>.SuspendRunnable origin=SUSPEND_CONVERSION
-          TYPE_OP type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=IMPLICIT_CAST typeOperand=kotlin.coroutines.SuspendFunction0<kotlin.Unit>
+          FUN ADAPTER_FOR_SUSPEND_CONVERSION name:suspendConversion visibility:local modality:FINAL <> ($receiver:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit [suspend]
-            BLOCK type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION
+            $receiver: VALUE_PARAMETER ADAPTER_PARAMETER_FOR_SUSPEND_CONVERSION name:callee type:kotlin.Function0<kotlin.Unit>
-              FUN ADAPTER_FOR_SUSPEND_CONVERSION name:suspendConversion visibility:local modality:FINAL <> ($receiver:kotlin.Function0<kotlin.Unit>) returnType:kotlin.Unit [suspend]
+            BLOCK_BODY
-                $receiver: VALUE_PARAMETER ADAPTER_PARAMETER_FOR_SUSPEND_CONVERSION name:callee type:kotlin.Function0<kotlin.Unit>
+              CALL 'public abstract fun invoke (): R of kotlin.Function0 declared in kotlin.Function0' type=kotlin.Unit origin=null
-                BLOCK_BODY
+                $this: GET_VAR 'callee: kotlin.Function0<kotlin.Unit> declared in <root>.test.suspendConversion' type=kotlin.Function0<kotlin.Unit> origin=null
-                  CALL 'public abstract fun invoke (): R of kotlin.Function0 declared in kotlin.Function0' type=kotlin.Unit origin=null
+          TYPE_OP type=<root>.SuspendRunnable origin=SAM_CONVERSION typeOperand=<root>.SuspendRunnable
-                    $this: GET_VAR 'callee: kotlin.Function0<kotlin.Unit> declared in <root>.test.suspendConversion' type=kotlin.Function0<kotlin.Unit> origin=null
+            FUNCTION_REFERENCE 'local final fun suspendConversion (): kotlin.Unit declared in <root>.test' type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION reflectionTarget=null
-              FUNCTION_REFERENCE 'local final fun suspendConversion (): kotlin.Unit declared in <root>.test' type=kotlin.coroutines.SuspendFunction0<kotlin.Unit> origin=SUSPEND_CONVERSION reflectionTarget=null
+              $receiver: GET_VAR 'var t: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null
-                $receiver: GET_VAR 'var t: kotlin.Function0<kotlin.Unit> declared in <root>.test' type=kotlin.Function0<kotlin.Unit> origin=null