Perform full build in case the output directory was deleted

Signed-off-by: Christoph Läubrich <[email protected]>

Author: laeubi

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/builder/MavenBuilderImpl.java

@@ -28,7 +28,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Predicate;
 
 import org.slf4j.Logger;
@@ -86,6 +86,10 @@ public class MavenBuilderImpl {
 
   private final Map<IProject, ProjectBuildState> deltaState = new ConcurrentHashMap<>();
 
+  private enum DeltaType {
+    INCREMENTAL, IRRELEVANT, FULL_BUILD, UNKOWN;
+  }
+
   public MavenBuilderImpl(DeltaProvider deltaProvider) {
     this.deltaProvider = deltaProvider;
     this.incrementalBuildFrameworks = loadIncrementalBuildFrameworks();
@@ -118,13 +122,14 @@ public Set<IProject> build(MavenSession session, IMavenProjectFacade projectFaca
 
     DeltaProvider deltaProvider = getDeltaProvider();
     IResourceDelta delta = deltaProvider.getDelta(project);
-    if(!hasRelevantDelta(projectFacade, delta)) {
+    DeltaType deltaType = hasRelevantDelta(projectFacade, delta);
+    if(deltaType == DeltaType.IRRELEVANT) {
       return Set.of(project);
     }
     ProjectBuildState buildState = deltaState.computeIfAbsent(project, ProjectBuildState::new);
     final BuildResultCollector participantResults = new BuildResultCollector();
     List<BuildContext> incrementalContexts = setupProjectBuildContext(project, kind, delta, participantResults,
-        buildState);
+        buildState, deltaType);
 
     debugBuildStart(debugHooks, projectFacade, kind, args, participants, delta, monitor);
 
@@ -200,15 +205,15 @@ public Set<IProject> build(MavenSession session, IMavenProjectFacade projectFaca
     return dependencies;
   }
 
-  private boolean hasRelevantDelta(IMavenProjectFacade projectFacade, IResourceDelta resourceDelta)
+  private DeltaType hasRelevantDelta(IMavenProjectFacade projectFacade, IResourceDelta resourceDelta)
       throws CoreException {
     if(resourceDelta == null) {
-      return true;
+      return DeltaType.FULL_BUILD;
     }
     IProject project = projectFacade.getProject();
     IPath buildOutputLocation = projectFacade.getBuildOutputLocation();
     if(project == null || buildOutputLocation == null) {
-      return true;
+      return DeltaType.UNKOWN;
     }
 
     Predicate<IPath> isOutput = toPrefixPredicate(projectFacade.getOutputLocation());
@@ -218,7 +223,7 @@ private boolean hasRelevantDelta(IMavenProjectFacade projectFacade, IResourceDel
     IPath projectPath = project.getFullPath();
     List<IPath> moduleLocations = projectFacade.getMavenProjectModules().stream()
         .map(module -> projectPath.append(module)).toList();
-    AtomicBoolean hasRelevantDelta = new AtomicBoolean();
+    AtomicReference<DeltaType> deltaType = new AtomicReference<>(DeltaType.IRRELEVANT);
     resourceDelta.accept(delta -> {
       IResource resource = delta.getResource();
       if(resource instanceof IFile) {
@@ -227,7 +232,8 @@ private boolean hasRelevantDelta(IMavenProjectFacade projectFacade, IResourceDel
           //anything in the build output is not interesting for a change as it is produced by the build
           // ... unless a classpath resource that existed before has been deleted, possibly by another builder
           if(isOutputOrTestOutput.test(fullPath) && !resource.exists()) {
-            hasRelevantDelta.set(true);
+            //in this case we should perform a full build as we can't know what mojo has placed data possible here...
+            deltaType.set(DeltaType.FULL_BUILD);
             return false;
           }
           return true;
@@ -239,12 +245,12 @@ private boolean hasRelevantDelta(IMavenProjectFacade projectFacade, IResourceDel
           }
         }
         //anything else has changed, so mark this as relevant an leave the loop
-        hasRelevantDelta.set(true);
+        deltaType.set(DeltaType.INCREMENTAL);
         return false;
       }
       return true;
     });
-    return hasRelevantDelta.get();
+    return deltaType.get();
   }
 
   private static Predicate<IPath> toPrefixPredicate(IPath location) {
@@ -255,12 +261,13 @@ private static Predicate<IPath> toPrefixPredicate(IPath location) {
   }
 
   private List<IIncrementalBuildFramework.BuildContext> setupProjectBuildContext(IProject project, int kind,
-      IResourceDelta delta, IIncrementalBuildFramework.BuildResultCollector results, ProjectBuildState buildState)
+      IResourceDelta delta, IIncrementalBuildFramework.BuildResultCollector results, ProjectBuildState buildState,
+      DeltaType deltaType)
       throws CoreException {
     List<IIncrementalBuildFramework.BuildContext> contexts = new ArrayList<>();
 
-    BuildDelta buildDelta = delta != null ? new ProjectBuildStateDelta(buildState, new EclipseResourceBuildDelta(delta))
-        : null;
+    BuildDelta buildDelta = deltaType == DeltaType.FULL_BUILD || delta == null ? null
+        : new ProjectBuildStateDelta(buildState, new EclipseResourceBuildDelta(delta));
     for(IIncrementalBuildFramework framework : incrementalBuildFrameworks) {
       contexts.add(framework.setupProjectBuildContext(project, kind, buildDelta, results));
     }
@@ -438,7 +445,7 @@ public void clean(MavenSession session, IMavenProjectFacade projectFacade,
 
     final BuildResultCollector participantResults = new BuildResultCollector();
     List<BuildContext> incrementalContexts = setupProjectBuildContext(project, IncrementalProjectBuilder.CLEAN_BUILD,
-        null, participantResults, null);
+        null, participantResults, null, DeltaType.UNKOWN);
 
     Map<Throwable, MojoExecutionKey> buildErrors = new LinkedHashMap<>();
     try {