From 1fa990b063893173b939fee1a6d9192c0388dd80 Mon Sep 17 00:00:00 2001
From: Ivan Gavrilovic <gavra@google.com>
Date: Tue, 21 May 2019 11:21:03 +0100
Subject: [PATCH] Support isolating APs that report multiple originating
 elements from the same file

It is possible for isolating annotation processor to report two or more
originating elements from the same source file when generating
sources/classes/resources. This commit makes sure the source file are
de-duped, so assertion that there is a single source file does not fail.

Test: IsolatingIncrementalProcessorsTest.testIsolatingWithMultipleOriginatingElements

This is improvement to https://youtrack.jetbrains.com/issue/KT-23880
---
 .../base/incremental/incrementalProcessors.kt      |  6 +++---
 .../IsolatingIncrementalProcessorTest.kt           | 13 +++++++++++++
 .../kotlin/kapt3/base/incremental/fixtures.kt      | 14 ++++++++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/plugins/kapt3/kapt3-base/src/org/jetbrains/kotlin/kapt3/base/incremental/incrementalProcessors.kt b/plugins/kapt3/kapt3-base/src/org/jetbrains/kotlin/kapt3/base/incremental/incrementalProcessors.kt
index 958ee45bb29..57fcddca9d6 100644
--- a/plugins/kapt3/kapt3-base/src/org/jetbrains/kotlin/kapt3/base/incremental/incrementalProcessors.kt
+++ b/plugins/kapt3/kapt3-base/src/org/jetbrains/kotlin/kapt3/base/incremental/incrementalProcessors.kt
@@ -124,15 +124,15 @@ internal class AnnotationProcessorDependencyCollector(private val runtimeProcTyp
     }
 }
 
-private fun getSrcFiles(elements: Array<out Element?>): List<File> {
+private fun getSrcFiles(elements: Array<out Element?>): Set<File> {
     return elements.filterNotNull().mapNotNull { elem ->
         var origin = elem
         while (origin.enclosingElement != null && origin.enclosingElement !is PackageElement) {
             origin = origin.enclosingElement
         }
         val uri = (origin as? Symbol.ClassSymbol)?.sourcefile?.toUri()?.takeIf { it.isAbsolute }
-        uri?.let { File(it) }
-    }
+        uri?.let { File(it).canonicalFile }
+    }.toSet()
 }
 
 enum class DeclaredProcType {
diff --git a/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/IsolatingIncrementalProcessorTest.kt b/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/IsolatingIncrementalProcessorTest.kt
index 412c5733cf1..223fa12b06a 100644
--- a/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/IsolatingIncrementalProcessorTest.kt
+++ b/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/IsolatingIncrementalProcessorTest.kt
@@ -107,4 +107,17 @@ class IsolationgIncrementalProcessorTest {
             ), isolating[1].getGeneratedToSources()
         )
     }
+
+    @Test
+    fun testIsolatingWithMultipleOriginatingElements() {
+        val srcFiles = listOf("User.java", "Observable.java").map { File(TEST_DATA_DIR, it) }
+        val isolating = listOf(ReportTwoOriginElements().toIsolating())
+        runAnnotationProcessing(srcFiles, isolating, generatedSources)
+
+        assertEquals(
+            mapOf(
+                generatedSources.resolve("test/UserGenerated.java") to File("plugins/kapt3/kapt3-base/testData/runner/incremental/User.java").absoluteFile
+            ), isolating[0].getGeneratedToSources()
+        )
+    }
 }
diff --git a/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/fixtures.kt b/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/fixtures.kt
index c0eb785cea6..100e791fe70 100644
--- a/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/fixtures.kt
+++ b/plugins/kapt3/kapt3-base/test/org/jetbrains/kotlin/kapt3/base/incremental/fixtures.kt
@@ -145,6 +145,20 @@ class SimpleGeneratingIfTypeDoesNotExist: SimpleProcessor() {
             }
         }
 
+        return false
+    }
+}
+
+open class ReportTwoOriginElements : SimpleProcessor() {
+    override fun process(annotations: MutableSet<out TypeElement>, roundEnv: RoundEnvironment): Boolean {
+        if (annotations.isEmpty()) return false
+
+        roundEnv.getElementsAnnotatedWith(annotations.single()).forEach {
+            it as TypeElement
+            // Report 2 elements from the same file as originating
+            filer.createSourceFile("${it.qualifiedName}Generated", it, it).openWriter().use { it.write("") }
+        }
+
         return false
     }
 }
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