Do not fail the DS build if one dependency failed to add

Currently it can happen that if a project has a "bad" dependency that
the whole build fails due to DS generation as the analyzer can't read
it.

This adds instead a warning and proceed because DS components can often
be generated anyways.

(cherry picked from commit 0d58b9d)

Author: laeubi

tycho-ds-plugin/src/main/java/org/eclipse/tycho/ds/DeclarativeServicesMojo.java

@@ -23,6 +23,7 @@
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugin.logging.Log;
 import org.apache.maven.plugins.annotations.Component;
 import org.apache.maven.plugins.annotations.LifecyclePhase;
 import org.apache.maven.plugins.annotations.Mojo;
@@ -145,7 +146,9 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 					return;
 				}
 				Version dsVersion = configuration.getSpecificationVersion();
-				getLog().info("Using Declarative Service specification version " + dsVersion + " to generate component definitions");
+				Log log = getLog();
+				log.info("Using Declarative Service specification version " + dsVersion
+						+ " to generate component definitions");
 				boolean isDs12 = dsVersion.getMajor() == 1 && dsVersion.getMinor() == 2;
 				String childPath = configuration.getPath();
 				File targetDirectory = new File(outputDirectory, childPath);
@@ -162,14 +165,18 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 					for (ClasspathEntry entry : classpath) {
 						List<File> locations = entry.getLocations();
 						for (File file : locations) {
-							if (file.exists() && !file.equals(outputDirectory)) {
-								analyzer.addClasspath(file);
+							if (file.exists() && !file.equals(outputDirectory) && file.length() > 0) {
+								try {
+									analyzer.addClasspath(file);
+								} catch (IOException e) {
+									log.warn("Can't add file " + file + " as classpath entry to ds analyzer",
+											log.isDebugEnabled() ? e : null);
+								}
 							}
 						}
 					}
 					pluginRealmHelper.visitPluginExtensions(project, session, ClasspathContributor.class, cpc -> {
-						List<ClasspathEntry> list = cpc.getAdditionalClasspathEntries(project,
-								Artifact.SCOPE_COMPILE);
+						List<ClasspathEntry> list = cpc.getAdditionalClasspathEntries(project, Artifact.SCOPE_COMPILE);
 						if (list != null && !list.isEmpty()) {
 							for (ClasspathEntry entry : list) {
 								for (File file : entry.getLocations()) {
@@ -183,7 +190,7 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 					});
 					if (isDs12) {
 						// see https://github.com/bndtools/bnd/issues/5548
-						getLog().warn(
+						log.warn(
 								"Generating of XML DS 1.2 might be not fully supported and validation is disabled (see https://github.com/bndtools/bnd/issues/5548), please upgrade to at least 1.3");
 					} else {
 						// https://bnd.bndtools.org/instructions/dsannotations-options.html
@@ -193,13 +200,14 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 					analyzer.addBasicPlugin(new DSAnnotations());
 					analyzer.analyze();
 					for (String warning : analyzer.getWarnings()) {
-						getLog().warn(warning);
+						log.warn(warning);
 					}
 					for (String error : analyzer.getErrors()) {
-						getLog().error(error);
+						log.error(error);
 					}
 					if (!analyzer.getErrors().isEmpty()) {
-						throw new MojoFailureException("Generation of Declarative Service components failed, see log for details");
+						throw new MojoFailureException(
+								"Generation of Declarative Service components failed, see log for details");
 					}
 					String components = analyzer.getProperty(SERVICE_COMPONENT_HEADER);
 					if (components == null || components.isBlank()) {
@@ -219,7 +227,7 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 							keep++;
 							continue;
 						}
-						getLog().info("\t" + name);
+						log.info("\t" + name);
 						generated++;
 						Resource resource = analyzer.getJar().getResource(component);
 						if (resource != null) {
@@ -229,9 +237,9 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 						}
 					}
 					if (keep > 0) {
-						getLog().info(generated + " component(s) where generated, " + keep + " where kept.");
+						log.info(generated + " component(s) where generated, " + keep + " where kept.");
 					} else {
-						getLog().info(generated + " component(s) where generated.");
+						log.info(generated + " component(s) where generated.");
 					}
 				}
 			} catch (Exception e) {