Add compatibility warning for suspend conversions

compiler/fir/analysis-tests/tests/org/jetbrains/kotlin/fir/FirOldFrontendDiagnosticsTestGenerated.java

@@ -23207,6 +23207,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             runTest("compiler/testData/diagnostics/tests/suspendConversion/severalConversionsInOneCall.kt");
         }
 
+        @TestMetadata("suspendConversionCompatibility.kt")
+        public void testSuspendConversionCompatibility() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.kt");
+        }
+
         @TestMetadata("suspendConversionDisabled.kt")
         public void testSuspendConversionDisabled() throws Exception {
             runTest("compiler/testData/diagnostics/tests/suspendConversion/suspendConversionDisabled.kt");

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/suspendConversionUtils.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.resolve.calls.components
 import org.jetbrains.kotlin.builtins.*
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.ParameterDescriptor
+import org.jetbrains.kotlin.resolve.calls.inference.model.LowerPriorityToPreserveCompatibility
 import org.jetbrains.kotlin.resolve.calls.model.*
 import org.jetbrains.kotlin.types.UnwrappedType
 
@@ -53,6 +54,8 @@ object SuspendTypeConversions : ParameterTypeConversion {
 
         candidate.resolvedCall.registerArgumentWithSuspendConversion(argument, nonSuspendParameterType)
 
+        candidate.addDiagnostic(LowerPriorityToPreserveCompatibility)
+
         return nonSuspendParameterType
     }
 }

compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.fir.kt

@@ -0,0 +1,28 @@
+// !LANGUAGE: +SuspendConversion
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION
+
+object Test1 {
+    fun foo(f: () -> Unit) {}
+
+    object Scope {
+        fun foo(f: suspend () -> Unit) {}
+
+        fun test(g: () -> Unit) {
+            <!DEBUG_INFO_CALL("fqName: Test1.foo; typeCall: function")!>foo(g)<!>
+        }
+    }
+}
+
+object Test2 {
+    fun <T> foo(f: suspend () -> T): T = TODO()
+    suspend fun bar(): Int = 0
+
+    object Scope {
+        fun bar(): String = ""
+
+        fun test() {
+            val result = foo(::bar)
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>result<!>
+        }
+    }
+}

compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.kt

@@ -0,0 +1,28 @@
+// !LANGUAGE: +SuspendConversion
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION
+
+object Test1 {
+    fun foo(f: () -> Unit) {}
+
+    object Scope {
+        fun foo(f: suspend () -> Unit) {}
+
+        fun test(g: () -> Unit) {
+            <!COMPATIBILITY_WARNING, DEBUG_INFO_CALL("fqName: Test1.foo; typeCall: function")!>foo(g)<!>
+        }
+    }
+}
+
+object Test2 {
+    fun <T> foo(f: suspend () -> T): T = TODO()
+    suspend fun bar(): Int = 0
+
+    object Scope {
+        fun bar(): String = ""
+
+        fun test() {
+            val result = foo(<!COMPATIBILITY_WARNING!>::bar<!>)
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>result<!>
+        }
+    }
+}

compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.txt

@@ -0,0 +1,36 @@
+package
+
+public object Test1 {
+    private constructor Test1()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun foo(/*0*/ f: () -> kotlin.Unit): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public object Scope {
+        private constructor Scope()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(/*0*/ f: suspend () -> kotlin.Unit): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public final fun test(/*0*/ g: () -> kotlin.Unit): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}
+
+public object Test2 {
+    private constructor Test2()
+    public final suspend fun bar(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun </*0*/ T> foo(/*0*/ f: suspend () -> T): T
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public object Scope {
+        private constructor Scope()
+        public final fun bar(): kotlin.String
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public final fun test(): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -23289,6 +23289,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTestWithFirVali
                 runTest("compiler/testData/diagnostics/tests/suspendConversion/severalConversionsInOneCall.kt");
             }
 
+            @TestMetadata("suspendConversionCompatibility.kt")
+            public void testSuspendConversionCompatibility() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.kt");
+            }
+
             @TestMetadata("suspendConversionDisabled.kt")
             public void testSuspendConversionDisabled() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/suspendConversion/suspendConversionDisabled.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -23209,6 +23209,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/suspendConversion/severalConversionsInOneCall.kt");
             }
 
+            @TestMetadata("suspendConversionCompatibility.kt")
+            public void testSuspendConversionCompatibility() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.kt");
+            }
+
             @TestMetadata("suspendConversionDisabled.kt")
             public void testSuspendConversionDisabled() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/suspendConversion/suspendConversionDisabled.kt");