UAST: Do not create UElements in non-JVM modules

plugins/uast-kotlin/build.gradle.kts

@@ -8,6 +8,7 @@ dependencies {
     compile(project(":compiler:frontend"))
     compile(project(":compiler:frontend.java"))
     compile(project(":compiler:light-classes"))
+    compile(project(":idea:idea-core"))
     compileOnly(intellijDep()) { includeJars("openapi", "idea", "util", "extensions", "asm-all") }
 
     testCompile(projectDist(":kotlin-test:kotlin-test-jvm"))

plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/KotlinUastLanguagePlugin.kt

@@ -32,11 +32,14 @@ import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.idea.KotlinLanguage
+import org.jetbrains.kotlin.idea.project.TargetPlatformDetector
+import org.jetbrains.kotlin.idea.util.module
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.jvm.platform.JvmPlatform
 import org.jetbrains.uast.*
 import org.jetbrains.uast.kotlin.declarations.KotlinUMethod
 import org.jetbrains.uast.kotlin.expressions.*
@@ -60,11 +63,22 @@ class KotlinUastLanguagePlugin : UastLanguagePlugin {
         return fileName.endsWith(".kt", false) || fileName.endsWith(".kts", false)
     }
 
+    private val PsiElement.isJvmElement
+        get() = try {
+            // Workaround for UAST used without full-fledged IDEA when ProjectFileIndex is not available
+            // If we can't get the module, act as if the current platform is JVM
+            module?.let { TargetPlatformDetector.getPlatform(it) } is JvmPlatform
+        } catch (e: Exception) {
+            true
+        }
+
     override fun convertElement(element: PsiElement, parent: UElement?, requiredType: Class<out UElement>?): UElement? {
+        if (!element.isJvmElement) return null
         return convertDeclarationOrElement(element, parent, requiredType)
     }
 
     override fun convertElementWithParent(element: PsiElement, requiredType: Class<out UElement>?): UElement? {
+        if (!element.isJvmElement) return null
         if (element is PsiFile) return convertDeclaration(element, null, requiredType)
         if (element is KtLightClassForFacade) return convertDeclaration(element, null, requiredType)