Experiment with missing symbol diagnostics from AA

kotlin-analysis-api/src/test/kotlin/com/google/devtools/ksp/processor/MissingSymbolsProcessor.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2026 Google LLC
+ * Copyright 2010-2026 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.devtools.ksp.processor
+
+import com.google.devtools.ksp.processing.Resolver
+import com.google.devtools.ksp.symbol.KSAnnotated
+
+class MissingSymbolsProcessor : AbstractTestProcessor() {
+
+    private val result = mutableListOf<String>()
+
+    override fun toResult(): List<String> = result.toList().sorted()
+
+    override fun process(resolver: Resolver): List<KSAnnotated> {
+        // TODO: Collect diagnostics somehow
+        resolver.getSymbolsWithAnnotation("Anno").forEach {
+            result.add(it.toString())
+        }
+        return emptyList()
+    }
+}

kotlin-analysis-api/src/test/kotlin/com/google/devtools/ksp/test/KSPUnitTestSuite.kt

@@ -536,6 +536,12 @@ abstract class KSPUnitTestSuite(
         runTest("$AA_PATH/getSymbolsWithAnnotation/metaAnnotations.kt")
     }
 
+    @TestMetadata("missingSymbols.kt")
+    @Test
+    fun testMissingSymbols() {
+        runTest("$AA_PATH/missingSymbols.kt")
+    }
+
     @TestMetadata("multipleModules.kt")
     @Test
     fun testMultipleModules() {

kotlin-analysis-api/testData/missingSymbols.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2026 Google LLC
+ * Copyright 2010-2026 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// TEST PROCESSOR: MissingSymbolsProcessor
+// EXPECTED:
+// ERROR
+// END
+
+// FILE: Main.kt
+
+annotation class Anno
+
+@Anno
+class MissingSymInImpl {
+    val x = a
+}