From 734250881237ca556858ae68caa155b77347ae17 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?H=C3=A9lios=20GILLES?= <h-gilles@efluid.fr>
Date: Mon, 27 Nov 2023 17:10:17 +0100
Subject: [PATCH] Add ability to add source/resource folder outside of the
 project basedir using linked folder

---
 .../add-source-resource/parent/java/A.java    |  5 ++
 .../parent/resources/res.txt                  |  0
 .../parent/test-resources/test.txt            |  0
 .../parent/test/ATest.java                    |  5 ++
 .../add-source-resource/submoduleA/pom.xml    | 80 +++++++++++++++++++
 .../m2e/jdt/tests/JavaConfigurationTest.java  |  6 ++
 .../AbstractJavaProjectConfigurator.java      | 47 ++++++++---
 7 files changed, 131 insertions(+), 12 deletions(-)
 create mode 100644 org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/java/A.java
 create mode 100644 org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/resources/res.txt
 create mode 100644 org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test-resources/test.txt
 create mode 100644 org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test/ATest.java
 create mode 100644 org.eclipse.m2e.jdt.tests/projects/add-source-resource/submoduleA/pom.xml

diff --git a/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/java/A.java b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/java/A.java
new file mode 100644
index 0000000000..396f5b59a4
--- /dev/null
+++ b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/java/A.java
@@ -0,0 +1,5 @@
+import java.io.Serializable;
+
+class ATest implements Serializable {
+	
+}
diff --git a/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/resources/res.txt b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/resources/res.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test-resources/test.txt b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test-resources/test.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test/ATest.java b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test/ATest.java
new file mode 100644
index 0000000000..396f5b59a4
--- /dev/null
+++ b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/parent/test/ATest.java
@@ -0,0 +1,5 @@
+import java.io.Serializable;
+
+class ATest implements Serializable {
+	
+}
diff --git a/org.eclipse.m2e.jdt.tests/projects/add-source-resource/submoduleA/pom.xml b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/submoduleA/pom.xml
new file mode 100644
index 0000000000..061c543cd3
--- /dev/null
+++ b/org.eclipse.m2e.jdt.tests/projects/add-source-resource/submoduleA/pom.xml
@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>foo.bar</groupId>
+  <artifactId>add-source-resource</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.10.1</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+    <plugins>
+      <plugin>
+      <groupId>org.codehaus.mojo</groupId>
+      <artifactId>build-helper-maven-plugin</artifactId>
+      <executions>
+        <execution>
+        <id>java</id>
+        <phase>generate-sources</phase>
+        <goals>
+          <goal>add-source</goal>
+        </goals>
+        <configuration>
+          <sources>
+          <source>../parent/java</source>
+          </sources>
+        </configuration>
+        </execution>
+        <execution>
+          <id>test</id>
+          <phase>generate-sources</phase>
+          <goals>
+            <goal>add-test-source</goal>
+          </goals>
+          <configuration>
+            <sources>
+              <source>../parent/test</source>
+            </sources>
+          </configuration>
+        </execution>
+        <execution>
+          <id>resources</id>
+          <phase>generate-resources</phase>
+          <goals>
+            <goal>add-resource</goal>
+          </goals>
+          <configuration>
+            <resources>
+              <resource>
+                <directory>../parent/resources</directory>
+              </resource>
+            </resources>
+          </configuration>
+        </execution>
+        <execution>
+          <id>test-resources</id>
+          <phase>generate-resources</phase>
+          <goals>
+            <goal>add-test-resource</goal>
+          </goals>
+          <configuration>
+            <resources>
+              <resource>
+                <directory>../parent/test-resources</directory>
+              </resource>
+            </resources>
+          </configuration>
+        </execution>
+      </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/org.eclipse.m2e.jdt.tests/src/org/eclipse/m2e/jdt/tests/JavaConfigurationTest.java b/org.eclipse.m2e.jdt.tests/src/org/eclipse/m2e/jdt/tests/JavaConfigurationTest.java
index e56ccb6798..57285384fb 100644
--- a/org.eclipse.m2e.jdt.tests/src/org/eclipse/m2e/jdt/tests/JavaConfigurationTest.java
+++ b/org.eclipse.m2e.jdt.tests/src/org/eclipse/m2e/jdt/tests/JavaConfigurationTest.java
@@ -132,6 +132,12 @@ public void testComplianceVsEnablePreviewSettings() throws CoreException, IOExce
 		assertEquals(JavaCore.ENABLED, project.getOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, false));
 		assertEquals(JavaCore.IGNORE, project.getOption(JavaCore.COMPILER_PB_REPORT_PREVIEW_FEATURES, false));
 	}
+
+	@Test
+	public void testAddSourceResource() throws CoreException, IOException, InterruptedException {
+		IJavaProject project = importResourceProject("/projects/add-source-resource/submoduleA/pom.xml");
+		assertEquals(4, project.getRawClasspath().length);
+	}
 	// --- utility methods ---
 
 	private static final Predicate<IClasspathEntry> TEST_SOURCES = cp -> cp.isTest()
diff --git a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/AbstractJavaProjectConfigurator.java b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/AbstractJavaProjectConfigurator.java
index 593febb513..5550ed90cc 100644
--- a/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/AbstractJavaProjectConfigurator.java
+++ b/org.eclipse.m2e.jdt/src/org/eclipse/m2e/jdt/internal/AbstractJavaProjectConfigurator.java
@@ -14,6 +14,7 @@
 package org.eclipse.m2e.jdt.internal;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -33,6 +34,7 @@
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.core.runtime.SubMonitor;
 import org.eclipse.jdt.core.IAccessRule;
 import org.eclipse.jdt.core.IClasspathAttribute;
@@ -134,6 +136,9 @@ public abstract class AbstractJavaProjectConfigurator extends AbstractProjectCon
 
   protected static final String DEFAULT_COMPILER_LEVEL = "1.5"; //$NON-NLS-1$
 
+  private static final QualifiedName LINKED_RESOURCE_PROPERTY = new QualifiedName(MavenJdtPlugin.PLUGIN_ID,
+      "linkedSource");
+
   @Override
   public void configure(ProjectConfigurationRequest request, IProgressMonitor monitor) throws CoreException {
     IProject project = request.mavenProjectFacade().getProject();
@@ -361,6 +366,9 @@ protected void addProjectSourceFolders(IClasspathDescriptor classpath, Map<Strin
           isTestResourcesSkipped.add(Boolean.FALSE);
         }
       }
+
+      cleanLinkedSourceDirs(project, monitor);
+
       addSourceDirs(classpath, project, mavenProject.getCompileSourceRoots(), classes.getFullPath(), inclusion,
           exclusion, mainSourceEncoding, mon.newChild(1), false);
       addResourceDirs(classpath, project, mavenProject, mavenProject.getBuild().getResources(), classes.getFullPath(),
@@ -468,6 +476,14 @@ protected void addSourceDirs(IClasspathDescriptor classpath, IProject project, L
 
   }
 
+  private void cleanLinkedSourceDirs(IProject project, IProgressMonitor monitor) throws CoreException {
+    for(IResource resource : project.members()) {
+      if(resource instanceof IFolder && "true".equals(resource.getPersistentProperty(LINKED_RESOURCE_PROPERTY))) {
+        resource.delete(false, monitor);
+      }
+    }
+  }
+
   private IClasspathEntryDescriptor getEnclosingEntryDescriptor(IClasspathDescriptor classpath, IPath fullPath) {
     for(IClasspathEntryDescriptor cped : classpath.getEntryDescriptors()) {
       if(cped.getPath().isPrefixOf(fullPath)) {
@@ -496,8 +512,13 @@ private void addResourceDirs(IClasspathDescriptor classpath, IProject project, M
         continue;
       }
       File resourceDirectory = new File(directory);
-      IPath relativePath = getProjectRelativePath(project, directory);
-      IResource r = project.findMember(relativePath);
+      String resourceCanonicalPath = null;
+      try {
+        resourceCanonicalPath = resourceDirectory.getCanonicalPath();
+      } catch(IOException ex) {
+        resourceCanonicalPath = resourceDirectory.getAbsolutePath();
+      }
+      IFolder r = getFolder(project, resourceCanonicalPath);
       if(r == project) {
         /*
          * Workaround for the Java Model Exception:
@@ -517,10 +538,6 @@ private void addResourceDirs(IClasspathDescriptor classpath, IProject project, M
         log.error("Skipping resource folder " + r.getFullPath());
         return;
       }
-      if(r == null) {
-        //this means the resources does not exits (yet) but might be created later on!
-        r = project.getFolder(relativePath);
-      }
       if(project.equals(r.getProject())) {
         IPath path = r.getFullPath();
         IClasspathEntryDescriptor enclosing = getEnclosingEntryDescriptor(classpath, path);
@@ -533,9 +550,8 @@ private void addResourceDirs(IClasspathDescriptor classpath, IProject project, M
           addResourceFolder(classpath, path, outputPath, addTestFlag);
         }
         // Set folder encoding (null = platform default)
-        IFolder resourceFolder = project.getFolder(relativePath);
-        if(resourceFolder.exists()) {
-          resourceFolder.setDefaultCharset(resourceEncoding, monitor);
+        if(r.exists()) {
+          r.setDefaultCharset(resourceEncoding, monitor);
         }
       } else {
         log.info("Not adding resources folder " + resourceDirectory.getAbsolutePath());
@@ -864,11 +880,18 @@ private void removeMavenClasspathContainer(IProject project) throws JavaModelExc
     }
   }
 
-  protected IFolder getFolder(IProject project, String absolutePath) {
+  protected IFolder getFolder(IProject project, String absolutePath) throws CoreException {
     if(project.getLocation().makeAbsolute().equals(IPath.fromOSString(absolutePath))) {
       return project.getFolder(project.getLocation());
     }
-    return project.getFolder(getProjectRelativePath(project, absolutePath));
+    IPath relativePath = getProjectRelativePath(project, absolutePath);
+    if(relativePath.segment(0).equals("..")) {
+      IFolder folder = project.getFolder(relativePath.lastSegment());
+      folder.createLink(new File(absolutePath).toURI(), IResource.REPLACE, null);
+      folder.setPersistentProperty(LINKED_RESOURCE_PROPERTY, "true");
+      return folder;
+    }
+    return project.getFolder(relativePath);
   }
 
   protected IPath getProjectRelativePath(IProject project, String absolutePath) {
@@ -879,7 +902,7 @@ protected IPath getProjectRelativePath(IProject project, String absolutePath) {
     } else if(absolutePath.startsWith(basedir.getAbsolutePath())) {
       relative = absolutePath.substring(basedir.getAbsolutePath().length() + 1);
     } else {
-      relative = absolutePath;
+      relative = IPath.fromOSString(absolutePath).makeRelativeTo(project.getLocation()).toString();
     }
     return IPath.fromOSString(relative.replace('\\', '/'));
   }