[ObjCExport] Fix extensions interface name

KT-66315

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/getExtensionFacades.kt

@@ -4,7 +4,6 @@ import org.jetbrains.kotlin.analysis.api.KtAnalysisSession
 import org.jetbrains.kotlin.analysis.api.symbols.KtFileSymbol
 import org.jetbrains.kotlin.backend.konan.objcexport.ObjCInterface
 import org.jetbrains.kotlin.backend.konan.objcexport.ObjCInterfaceImpl
-import org.jetbrains.kotlin.objcexport.analysisApiUtils.getFileName
 
 private const val extensionsCategoryName = "Extensions"
 
@@ -49,26 +48,33 @@ internal val ObjCInterface.isExtensionsFacade: Boolean
  * See related [getTopLevelFacade]
  */
 context(KtAnalysisSession, KtObjCExportSession)
-fun KtFileSymbol.getExtensionsFacade(): ObjCInterface? {
+fun KtFileSymbol.getExtensionFacades(): List<ObjCInterface> {
 
     val extensions = getFileScope()
         .getCallableSymbols().filter { it.isExtension }
-        .toList().sortedWith(StableCallableOrder)
-        .ifEmpty { return null }
+        .toList()
+        .sortedWith(StableCallableOrder)
+        .ifEmpty { return emptyList() }
+        .groupBy {
+            val classSymbol = it.receiverParameter?.type?.expandedClassSymbol
+            classSymbol?.getObjCClassOrProtocolName()?.objCName
+        }
+        .mapNotNull { (key, value) ->
+            if (key == null) return@mapNotNull null else key to value
+        }
 
-    val fileName = getFileName()
-        ?: throw IllegalStateException("File '$this' cannot be translated without file name")
-
-    return ObjCInterfaceImpl(
-        name = fileName,
-        comment = null,
-        origin = null,
-        attributes = emptyList(),
-        superProtocols = emptyList(),
-        members = extensions.mapNotNull { it.translateToObjCExportStub() },
-        categoryName = extensionsCategoryName,
-        generics = emptyList(),
-        superClass = null,
-        superClassGenerics = emptyList()
-    )
+    return extensions.map { (objCName, extensionSymbols) ->
+        ObjCInterfaceImpl(
+            name = objCName,
+            comment = null,
+            origin = null,
+            attributes = emptyList(),
+            superProtocols = emptyList(),
+            members = extensionSymbols.mapNotNull { ext -> ext.translateToObjCExportStub() },
+            categoryName = extensionsCategoryName,
+            generics = emptyList(),
+            superClass = null,
+            superClassGenerics = emptyList()
+        )
+    }
 }

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/getTopLevelFacade.kt

@@ -43,7 +43,7 @@ import org.jetbrains.kotlin.objcexport.analysisApiUtils.getDefaultSuperClassOrPr
  *
  * Where `FooKt` would be the "top level interface file facade" returned by this function.
  *
- * See related [getExtensionsFacade]
+ * See related [getExtensionFacades]
  */
 context(KtAnalysisSession, KtObjCExportSession)
 fun KtFileSymbol.getTopLevelFacade(): ObjCInterface? {

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/translateToObjCHeader.kt

@@ -109,10 +109,12 @@ private class KtObjCExportHeaderGenerator {
 
     context(KtAnalysisSession, KtObjCExportSession)
     private fun translateFileSymbol(symbol: KtFileSymbol) {
-        symbol.getExtensionsFacade()?.let { extensionFacade ->
-            objCStubs += extensionFacade
-            enqueueDependencyClasses(extensionFacade)
-            objCClassForwardDeclarations += extensionFacade.name
+        symbol.getExtensionFacades().let { extensionFacades ->
+            extensionFacades.forEach { facade ->
+                objCStubs += facade
+                enqueueDependencyClasses(facade)
+                objCClassForwardDeclarations += facade.name
+            }
         }
 
         symbol.getTopLevelFacade()?.let { topLevelFacade ->
@@ -146,10 +148,10 @@ private class KtObjCExportHeaderGenerator {
         symbol.getDeclaredSuperInterfaceSymbols()
             .filter { it.isVisibleInObjC() }
             .forEach { superInterfaceSymbol ->
-            translateClassOrObjectSymbol(superInterfaceSymbol)?.let {
-                objCProtocolForwardDeclarations += it.name
+                translateClassOrObjectSymbol(superInterfaceSymbol)?.let {
+                    objCProtocolForwardDeclarations += it.name
+                }
             }
-        }
 
         symbol.getSuperClassSymbolNotAny()?.let { superClassSymbol ->
             translateClassOrObjectSymbol(superClassSymbol)?.let {