[MCOMPILER-538] Do not add target/generated-sources/annotations to the source roots

• Type: Bug
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.11.0
• Fix Version/s: waiting-for-feedback
• Assignee: Slawomir Jaranowski
• Reporter: Daniel Mensinger
• Created: 15/Jun/23 06:54
• Updated: 23/Dec/23 00:14

Description

Adding the generated source root (target/generated-sources/annotations) is not required for javac. Additionally adding the generated source root results in compilation errors with annotation processors generating code unless the generated-sources dir is cleaned.

Specifically, the following steps result in compilation errors:

1. run mvn clean
2. Modify a source file that is consumed by the annotation processor so that there is a compilation error, but the annotation processor still runs (add or remove a parameter in a method call).
3. run mvn compile --> the generated file exists but there is no class file for the source file.
4. Fix the "bug" from step 2
5. run mvn compile again --> compilation should succeed, but it fails.

---

Example code: https://github.com/mensinda/quarkus-stuff/tree/annotationProcessingTest

Use the annotationProcessingTest branch!

For step 2 this change can be used:

diff --git a/code/src/main/java/bar/MyAnnotatedClass.java b/code/src/main/java/bar/MyAnnotatedClass.java
index bbfef7a..a303924 100644
--- a/code/src/main/java/bar/MyAnnotatedClass.java
+++ b/code/src/main/java/bar/MyAnnotatedClass.java
@@ -4,7 +4,7 @@ import foo.MyAnnotation;

 @MyAnnotation
 public class MyAnnotatedClass {
-    MyGeneratedClass generatedClass = new MyGeneratedClass();
+    MyGeneratedClass generatedClass = new MyGeneratedClass(false);

     // foo

 
To see that not adding target/generated-sources/annotations helps run mvn -X compile and copy the Command line options:. Then run javac manually, but remove the target/generated-sources/annotations from the -sourcepath list, but not the -s parameter.

---

PR with a fix: https://github.com/apache/maven-compiler-plugin/pull/191

Issue Links

• is related to: MCOMPILER-333 Incremental compilation causes "mvn clean compile compile" to fail
• relates to: MCOMPILER-540 useIncrementalCompilation=false may add generated sources to the sources list
• links to: GitHub Pull Request #191