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.FirTypeRef
+import org.jetbrains.kotlin.fir.types.*
 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
     }