Kapt: Allow empty .kt files list in kapt in order to support kapt with Java-only source files. (KT-15675)

Author: yanex

plugins/kapt3/src/org/jetbrains/kotlin/kapt3/Kapt3Extension.kt

@@ -126,11 +126,6 @@ abstract class AbstractKapt3Extension(
 
         fun doNotGenerateCode() = AnalysisResult.Companion.success(BindingContext.EMPTY, module, shouldGenerateCode = false)
 
-        if (files.isEmpty()) {
-            logger.info("No Kotlin source files, aborting")
-            return if (aptOnly) doNotGenerateCode() else null
-        }
-
         logger.info { "Initial analysis took ${System.currentTimeMillis() - pluginInitializedTime} ms" }
         logger.info { "Kotlin files to compile: " + files.map { it.virtualFile?.name ?: "<in memory ${it.hashCode()}>" } }
 
@@ -154,6 +149,12 @@ abstract class AbstractKapt3Extension(
             if (thr !is KaptError || thr.kind != KaptError.Kind.ERROR_RAISED) {
                 logger.exception(thr)
             }
+
+            // We don't have any Kotlin files, so there isn't anything we can report diagnostic on
+            if (files.isEmpty()) {
+                throw thr
+            }
+
             bindingTrace.report(ErrorsKapt3.KAPT3_PROCESSING_ERROR.on(files.first()))
             return null // Compilation will be aborted anyway because of the error above
         } finally {