From dc88beb33aac6a6c8239fcfafabfa0027c2ced88 Mon Sep 17 00:00:00 2001
From: Tamas Cservenak <tamas@cservenak.net>
Date: Fri, 10 Apr 2026 14:09:09 +0200
Subject: [PATCH] Feat: Add Automatic Module Names to Maven JAR Manifests

Note: by doing this, Maven is not modular, as there are split packages
still present.
---
 maven-artifact/pom.xml            |  4 ++++
 maven-builder-support/pom.xml     |  4 ++++
 maven-compat/pom.xml              |  4 ++++
 maven-core/pom.xml                |  4 ++++
 maven-embedder/pom.xml            |  4 ++++
 maven-jline/pom.xml               |  4 ++++
 maven-model-builder/pom.xml       |  4 ++++
 maven-model/pom.xml               |  1 +
 maven-plugin-api/pom.xml          |  4 ++++
 maven-repository-metadata/pom.xml |  4 ++++
 maven-resolver-provider/pom.xml   |  4 ++++
 maven-settings-builder/pom.xml    |  4 ++++
 maven-settings/pom.xml            |  4 ++++
 maven-slf4j-provider/pom.xml      |  4 ++++
 pom.xml                           | 20 ++++++++++++++++++++
 15 files changed, 73 insertions(+)

diff --git a/maven-artifact/pom.xml b/maven-artifact/pom.xml
index 16396244395c..4a0b04bbc9ea 100644
--- a/maven-artifact/pom.xml
+++ b/maven-artifact/pom.xml
@@ -30,6 +30,10 @@ under the License.
 
   <name>Maven Artifact</name>
 
+  <properties>
+    <moduleNameSuffix>artifact</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
diff --git a/maven-builder-support/pom.xml b/maven-builder-support/pom.xml
index 609b11a59e97..fd85ac2b6935 100644
--- a/maven-builder-support/pom.xml
+++ b/maven-builder-support/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Builder Support</name>
   <description>Support for descriptor builders (model, setting, toolchains)</description>
 
+  <properties>
+    <moduleNameSuffix>builder</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
diff --git a/maven-compat/pom.xml b/maven-compat/pom.xml
index 01ffd81e109e..0b772b3ed54c 100644
--- a/maven-compat/pom.xml
+++ b/maven-compat/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Compat</name>
   <description>Maven2 classes maintained as compatibility layer.</description>
 
+  <properties>
+    <moduleNameSuffix>compat</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.apache.maven</groupId>
diff --git a/maven-core/pom.xml b/maven-core/pom.xml
index 6867da4a0347..b89a405c1286 100644
--- a/maven-core/pom.xml
+++ b/maven-core/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Core</name>
   <description>Maven Core classes.</description>
 
+  <properties>
+    <moduleNameSuffix>core</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <!--  Maven -->
     <dependency>
diff --git a/maven-embedder/pom.xml b/maven-embedder/pom.xml
index f8b548f9eb7a..5b13cd1401de 100644
--- a/maven-embedder/pom.xml
+++ b/maven-embedder/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Embedder</name>
   <description>Maven embeddable component, with CLI and logging support.</description>
 
+  <properties>
+    <moduleNameSuffix>embedder</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.apache.maven</groupId>
diff --git a/maven-jline/pom.xml b/maven-jline/pom.xml
index e7db3548d685..ac0617df8d0c 100644
--- a/maven-jline/pom.xml
+++ b/maven-jline/pom.xml
@@ -30,6 +30,10 @@ under the License.
   <name>Maven 3 JLine integration</name>
   <description>Provides the JLine integration in Maven</description>
 
+  <properties>
+    <moduleNameSuffix>jline</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.jline</groupId>
diff --git a/maven-model-builder/pom.xml b/maven-model-builder/pom.xml
index c0ff1dd2d266..268dd2d3c27d 100644
--- a/maven-model-builder/pom.xml
+++ b/maven-model-builder/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Model Builder</name>
   <description>The effective model builder, with inheritance, profile activation, interpolation, ...</description>
 
+  <properties>
+    <moduleNameSuffix>model.builder</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
diff --git a/maven-model/pom.xml b/maven-model/pom.xml
index 75709f0c0596..ca28f2244041 100644
--- a/maven-model/pom.xml
+++ b/maven-model/pom.xml
@@ -33,6 +33,7 @@ under the License.
 
   <properties>
     <checkstyle.violation.ignore>FileLength</checkstyle.violation.ignore>
+    <moduleNameSuffix>model</moduleNameSuffix>
   </properties>
 
   <dependencies>
diff --git a/maven-plugin-api/pom.xml b/maven-plugin-api/pom.xml
index da17be392696..ab2b02ff2201 100644
--- a/maven-plugin-api/pom.xml
+++ b/maven-plugin-api/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Plugin API</name>
   <description>The API for plugins - Mojos - development.</description>
 
+  <properties>
+    <moduleNameSuffix>plugin</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.apache.maven</groupId>
diff --git a/maven-repository-metadata/pom.xml b/maven-repository-metadata/pom.xml
index 1221112d4e22..8f5fcbd3f3f0 100644
--- a/maven-repository-metadata/pom.xml
+++ b/maven-repository-metadata/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Repository Metadata Model</name>
   <description>Per-directory local and remote repository metadata.</description>
 
+  <properties>
+    <moduleNameSuffix>repository.metadata</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
diff --git a/maven-resolver-provider/pom.xml b/maven-resolver-provider/pom.xml
index 9df5e67f513d..6d25e38fa897 100644
--- a/maven-resolver-provider/pom.xml
+++ b/maven-resolver-provider/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Artifact Resolver Provider</name>
   <description>Extensions to Maven Resolver for utilizing Maven POM and repository metadata.</description>
 
+  <properties>
+    <moduleNameSuffix>resolver.provider</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.apache.maven</groupId>
diff --git a/maven-settings-builder/pom.xml b/maven-settings-builder/pom.xml
index f897fb0694e8..b7387a762907 100644
--- a/maven-settings-builder/pom.xml
+++ b/maven-settings-builder/pom.xml
@@ -37,6 +37,10 @@ under the License.
     </contributor>
   </contributors>
 
+  <properties>
+    <moduleNameSuffix>settings.builder</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.apache.maven</groupId>
diff --git a/maven-settings/pom.xml b/maven-settings/pom.xml
index 5ae53fb767c8..6408b2e9adbf 100644
--- a/maven-settings/pom.xml
+++ b/maven-settings/pom.xml
@@ -31,6 +31,10 @@ under the License.
   <name>Maven Settings</name>
   <description>Maven Settings model.</description>
 
+  <properties>
+    <moduleNameSuffix>settings</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
diff --git a/maven-slf4j-provider/pom.xml b/maven-slf4j-provider/pom.xml
index bee59b4c035d..7c76f4930c4d 100644
--- a/maven-slf4j-provider/pom.xml
+++ b/maven-slf4j-provider/pom.xml
@@ -32,6 +32,10 @@ under the License.
   <description>Maven SLF4J provider based on SLF4J's simple provider, extended to support Maven styled colors
     for levels and stacktraces rendering.</description>
 
+  <properties>
+    <moduleNameSuffix>slf4j.provider</moduleNameSuffix>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.slf4j</groupId>
diff --git a/pom.xml b/pom.xml
index e0b72c0dda98..7fdb3b3fbd8b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -158,6 +158,11 @@ under the License.
     <checkstyle.excludes>**/package-info.java</checkstyle.excludes>
     <project.build.outputTimestamp>2026-03-24T21:15:50Z</project.build.outputTimestamp>
     <jlineVersion>3.30.9</jlineVersion>
+
+    <!-- The JPMS module name elements used in the Automatic-Module-Name -->
+    <!-- Note: Maven 3 can never become "pure modular" thing, we leave that to Maven 4+ -->
+    <moduleNamePrefix>${project.groupId}.v3.</moduleNamePrefix>
+    <moduleNameSuffix>invalid</moduleNameSuffix>
   </properties>
 
   <!--bootstrap-start-comment-->
@@ -527,6 +532,21 @@ under the License.
   <build>
     <pluginManagement>
       <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-jar-plugin</artifactId>
+          <configuration>
+            <archive>
+              <manifest>
+                <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
+                <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
+              </manifest>
+              <manifestEntries>
+                <Automatic-Module-Name>${moduleNamePrefix}${moduleNameSuffix}</Automatic-Module-Name>
+              </manifestEntries>
+            </archive>
+          </configuration>
+        </plugin>
         <plugin>
           <groupId>org.codehaus.plexus</groupId>
           <artifactId>plexus-component-metadata</artifactId>