FIR Java: implement "appendErasedType" thus adding predefined signatures

Related to KT-29937

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassEnhancementScope.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.java.declarations.FirJavaMethod
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaValueParameter
 import org.jetbrains.kotlin.fir.java.enhancement.*
 import org.jetbrains.kotlin.fir.java.enhancement.EnhancementSignatureParts
+import org.jetbrains.kotlin.fir.java.toNotNullConeKotlinType
 import org.jetbrains.kotlin.fir.java.types.FirJavaTypeRef
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
@@ -26,8 +27,7 @@ import org.jetbrains.kotlin.fir.symbols.ConePropertySymbol
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
-import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
+import org.jetbrains.kotlin.fir.types.*
-import org.jetbrains.kotlin.fir.types.FirTypeRef
 import org.jetbrains.kotlin.ir.expressions.IrConstKind
 import org.jetbrains.kotlin.load.java.AnnotationTypeQualifierResolver
 import org.jetbrains.kotlin.load.java.descriptors.NullDefaultValue
@@ -173,17 +173,38 @@ class JavaClassEnhancementScope(
 
         append("(")
         for (parameter in valueParameters) {
-            // TODO: appendErasedType(parameter.returnTypeRef)
+            appendErasedType(parameter.returnTypeRef)
         }
         append(")")
 
         if (this@computeJvmDescriptor !is FirJavaMethod || (returnTypeRef as FirJavaTypeRef).isVoid()) {
             append("V")
         } else {
-            // TODO: appendErasedType(returnTypeRef)
+            appendErasedType(returnTypeRef)
         }
     }
 
+    private fun StringBuilder.appendErasedType(typeRef: FirTypeRef) {
+        when (typeRef) {
+            is FirResolvedTypeRef -> appendConeType(typeRef.type)
+            is FirJavaTypeRef -> appendConeType(typeRef.toNotNullConeKotlinType(session))
+        }
+    }
+
+    private fun StringBuilder.appendConeType(coneType: ConeKotlinType) {
+        append("L")
+        when (coneType) {
+            is ConeClassLikeType -> {
+                val classId = coneType.lookupTag.classId
+                append(classId.packageFqName.asString().replace(".", "/"))
+                append("/")
+                append(classId.relativeClassName)
+            }
+            is ConeTypeParameterType -> append(coneType.lookupTag.name)
+        }
+        append(";")
+    }
+
     private fun FirJavaTypeRef.isVoid(): Boolean {
         return type is JavaPrimitiveType && type.type == null
     }

idea/testData/fir/multiModule/fullWithJavaPredefinedSignature/extraDump.java.txt

@@ -0,0 +1,2 @@
+<T> public abstract interface MyIterable : R|java/lang/Iterable<T>| {
+}

idea/testData/fir/multiModule/fullWithJavaPredefinedSignature/jvm/MyIterable.java

@@ -0,0 +1 @@
+public interface MyIterable<T> extends Iterable<T>

idea/testData/fir/multiModule/fullWithJavaPredefinedSignature/jvm/test.kt

@@ -0,0 +1,6 @@
+interface UseIterable : MyIterable<String> {
+    fun test() {
+        val it = iterator()
+        val split = spliterator()
+    }
+}

idea/testData/fir/multiModule/fullWithJavaPredefinedSignature/jvm/test.txt

@@ -0,0 +1,8 @@
+FILE: test.kt
+    public abstract interface UseIterable : R|MyIterable<kotlin/String>| {
+        public open function test(): R|kotlin/Unit| {
+            val it: R|error: Not supported: FirImplicitTypeRefImpl| = R|FakeOverride<java/lang/Iterable.iterator: R|ft<kotlin/collections/MutableIterator<ft<T, T?>>, kotlin/collections/Iterator<ft<T, T?>>?>|!>|()
+            val split: R|error: Not supported: FirImplicitTypeRefImpl| = R|FakeOverride<java/lang/Iterable.spliterator: R|ft<java/util/Spliterator<ft<T, T>>, java/util/Spliterator<ft<T, T>>>|>|()
+        }
+
+    }

idea/tests/org/jetbrains/kotlin/idea/fir/AbstractFirMultiModuleResolveTest.kt

@@ -53,10 +53,12 @@ abstract class AbstractFirMultiModuleResolveTest : AbstractMultiModuleTest() {
 
     fun doTest(dirPath: String) {
         setupMppProjectFromDirStructure(File(dirPath))
+        val useFullJdk = "full" in dirPath
+        val jdkKind = if (useFullJdk) TestJdkKind.FULL_JDK else TestJdkKind.MOCK_JDK
         for (module in project.allModules().drop(1)) {
             ConfigLibraryUtil.configureSdk(
                 module,
-                PluginTestCaseBase.addJdk(testRootDisposable) { PluginTestCaseBase.jdk(TestJdkKind.MOCK_JDK) }
+                PluginTestCaseBase.addJdk(testRootDisposable) { PluginTestCaseBase.jdk(jdkKind) }
             )
         }
         doFirResolveTest(dirPath)

idea/tests/org/jetbrains/kotlin/idea/fir/FirMultiModuleResolveTestGenerated.java

@@ -59,6 +59,11 @@ public class FirMultiModuleResolveTestGenerated extends AbstractFirMultiModuleRe
         runTest("idea/testData/fir/multiModule/basicWithPrimitiveJava/");
     }
 
+    @TestMetadata("fullWithJavaPredefinedSignature")
+    public void testFullWithJavaPredefinedSignature() throws Exception {
+        runTest("idea/testData/fir/multiModule/fullWithJavaPredefinedSignature/");
+    }
+
     @TestMetadata("javaInheritsRawKotlin")
     public void testJavaInheritsRawKotlin() throws Exception {
         runTest("idea/testData/fir/multiModule/javaInheritsRawKotlin/");