Improved logging infrastructure and plugged Log4J in the scala-ide.sd…

…t.core

project.

We used to have too many alternatives to create log items (Eclipse Log
framework, our ad-hoc naive internal Logger and println statements originating
from scalac). In short, we did not have an ideal logging infrastructure.

Now, I plugged Log4J as the backend logger (I'll refer to it as the "default
logger" in the rest of this commit message), which replaces our naive ad-hoc
Logger. Further, all log events occurring in the Eclipse Log Framework are now
*forwarded* to the default logger. Also, the Standard Output and Standard Error
are *redirected* to the default logger.  The  goal is to have a single place
to consult the log, and that is now the *scala-ide.log* file that is produced
by the default logger, located in

  ${workspace}/.metadata/.plugin/org.scala-ide.sdt.core/

It's easy to consult the log from within Eclipse, just open the Eclipse
Preferences, then Scala > Logging, and there is a link to open the
*scala-ide.log* file in the editor (though, mind that it is not automatically
refreshed while it's open).

From the same preference's page, you can also control the amount of produced
log, i.e., you can set the log level that better suits you (the default level
is WARNING).  If needed, you can also enable a console appender to print all
produced log items in the console (this is quite handy when doing development
on the Scala IDE sources).

To get a handle on the loggers you simply need to mix-in the HasLogger trait,
which contains a reference to both the default logger and the Eclipse Log. You
may wonder why we have two loggers. The reason is simple, if you want to
communicate a message to the user, you should use the Eclipse Log. This becayse
messages sent to the Eclipse Log are shown in the Eclipse Log View (remember
that all messages sent to the Eclipse Log are also forwarded to the default
logger, so you don't need to log the same message twice). In all other cases,
you should use th default logger.

Finally, I removed the "plugininfo" option, which it was used to enable debug
information in the ScalaIndexBuilder. As a matter of fact, the amount of logged
information can now be easily controlled through Log Levels.

One element I'm not happy with is that I plugged Log4J within the
scala-ide.sdt.core project and not as an external plug-in. I've tried to do so
but failed due to my lack of understanding of OSGi.  This is something that I
believe we should do at some point (maybe someone can help with this?!).

Fixes #1000880.

org.scala-ide.sdt.core.tests/src/scala/tools/eclipse/pc/PresentationCompilerTest.scala

@@ -4,7 +4,7 @@ package pc
 import scala.tools.eclipse.javaelements.ScalaCompilationUnit
 import scala.tools.eclipse.javaelements.ScalaSourceFile
 import scala.tools.eclipse.testsetup.SDTTestUtils
-import scala.tools.eclipse.util.Logger
+import scala.tools.eclipse.logging.Logger
 import scala.tools.nsc.interactive.InteractiveReporter
 import org.eclipse.jdt.core.ICompilationUnit
 import org.junit.Assert._
@@ -31,7 +31,7 @@ class PresentationCompilerTest {
         compiler.withStructure(sourceFile, keepLoaded = true) { tree =>
           compiler.askOption { () =>
             val overrideIndicatorBuilder = new compiler.OverrideIndicatorBuilderTraverser(unit, new java.util.HashMap) {
-              override val logger = mockLogger
+              override val eclipseLog = mockLogger
             }
             // if the unit is not kept loaded (i.e., `keepLoaded = false`), then a message 
             // "Error creating override indicators" is reported. That is why this test checks
@@ -43,7 +43,7 @@ class PresentationCompilerTest {
     }()
 
     // verify
-    verify(mockLogger, times(0)).error(any(), any())
+    verify(mockLogger, times(0)).error(any())
   }
 
   @Test

org.scala-ide.sdt.core/.classpath

@@ -8,5 +8,6 @@
 	<classpathentry kind="con" path="org.scala-ide.sdt.launching.SCALA_CONTAINER"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
 	<classpathentry kind="lib" path="lib/miglayout-3.7.4.jar"/>
+	<classpathentry kind="lib" path="lib/log4j-1.2.16.jar" sourcepath="lib/log4j-1.2.16-sources.jar"/>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>

org.scala-ide.sdt.core/META-INF/MANIFEST.MF

@@ -90,5 +90,6 @@ Export-Package:
  scala.tools.eclipse.wizards
 Bundle-RequiredExecutionEnvironment: J2SE-1.5
 Bundle-ClassPath: .,
- lib/miglayout-3.7.4.jar
+ lib/miglayout-3.7.4.jar,
+ lib/log4j-1.2.16.jar
 

org.scala-ide.sdt.core/plugin.xml

@@ -88,6 +88,12 @@
             class="scala.tools.eclipse.properties.ImplicitsPreferencePage"
             id="org.scala-ide.sdt.core.properties.Implicits"
             name="Implicits">
+      </page>
+      <page
+            category="org.scala-ide.sdt.core.preferences"
+            class="scala.tools.eclipse.logging.ui.properties.LoggingPreferencePage"
+            id="org.scala-ide.sdt.core.properties.Logging"
+            name="Logging">
       </page>      
    </extension>
 
@@ -745,6 +751,9 @@
      <initializer
            class="scala.tools.eclipse.properties.ImplicitsPagePreferenceInitializer">
      </initializer>
+     <initializer
+           class="scala.tools.eclipse.logging.ui.properties.LoggingPreferencePageInitializer">
+     </initializer>
   </extension>
 
   <extension point="org.eclipse.core.expressions.propertyTesters">

org.scala-ide.sdt.core/pom.xml

@@ -13,6 +13,7 @@
 
   <properties>
     <miglayout.version>3.7.4</miglayout.version>
+    <log4j.version>1.2.16</log4j.version>
   </properties>
 
   <dependencies>
@@ -23,6 +24,30 @@
     	<type>jar</type>
     	<scope>compile</scope>
     </dependency>
+    <dependency>
+	  <groupId>log4j</groupId>
+	  <artifactId>log4j</artifactId>
+	  <version>${log4j.version}</version>
+	  <scope>compile</scope>
+	  <exclusions>
+        <exclusion>
+          <groupId>javax.mail</groupId>
+          <artifactId>mail</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>javax.jms</groupId>
+          <artifactId>jms</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.sun.jdmk</groupId>
+          <artifactId>jmxtools</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>com.sun.jmx</groupId>
+          <artifactId>jmxri</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
   </dependencies>
 
   <build>
@@ -96,6 +121,19 @@
             </goals>
             <configuration>
               <artifactItems>
+                <artifactItem>
+                  <groupId>log4j</groupId>
+                  <artifactId>log4j</artifactId>
+                  <version>${log4j.version}</version>
+                  <outputDirectory>${basedir}/lib</outputDirectory>
+                </artifactItem>
+                <artifactItem>
+                  <groupId>log4j</groupId>
+                  <artifactId>log4j</artifactId>
+                  <version>${log4j.version}</version>
+                  <outputDirectory>${basedir}/lib</outputDirectory>
+                  <classifier>sources</classifier>
+                </artifactItem>
                 <artifactItem>
                   <groupId>com.miglayout</groupId>
                   <artifactId>miglayout</artifactId>

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaBuilder.scala

@@ -13,7 +13,7 @@ import org.eclipse.jdt.internal.core.JavaModelManager
 import org.eclipse.jdt.internal.core.builder.{ JavaBuilder, State }
 import scala.tools.eclipse.javaelements.JDTUtils
 import scala.tools.eclipse.util.{ FileUtils, ReflectionUtils }
-import util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 import scala.tools.nsc.interactive.RefinedBuildManager
 
 class ScalaBuilder extends IncrementalProjectBuilder with HasLogger {

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaHyperlinkDetector.scala

@@ -13,7 +13,7 @@ import org.eclipse.jdt.internal.ui.javaeditor.{ EditorUtility, JavaElementHyperl
 import org.eclipse.jdt.ui.actions.OpenAction
 import org.eclipse.jdt.internal.ui.javaeditor.JavaEditor
 import javaelements.{ ScalaCompilationUnit, ScalaSelectionEngine, ScalaSelectionRequestor }
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 class ScalaHyperlinkDetector extends AbstractHyperlinkDetector with HasLogger {
   def detectHyperlinks(viewer: ITextViewer, region: IRegion, canShowMultipleHyperlinks: Boolean): Array[IHyperlink] = {

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaPlugin.scala

@@ -28,12 +28,13 @@ import scala.tools.eclipse.util.OSGiUtils.pathInBundle
 import scala.tools.eclipse.templates.ScalaTemplateManager
 import org.eclipse.jdt.ui.PreferenceConstants
 import org.eclipse.core.resources.IResourceDelta
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 import org.osgi.framework.Bundle
 import scala.tools.eclipse.util.Utils
 import org.eclipse.jdt.core.ICompilationUnit
 import scala.tools.nsc.io.AbstractFile
 import scala.tools.eclipse.util.EclipseResource
+import scala.tools.eclipse.logging.PluginLogConfigurator
 
 object ScalaPlugin {
   var plugin: ScalaPlugin = _
@@ -46,7 +47,7 @@ object ScalaPlugin {
   def getShell: Shell = getWorkbenchWindow map (_.getShell) orNull
 }
 
-class ScalaPlugin extends AbstractUIPlugin with IResourceChangeListener with IElementChangedListener with IPartListener with HasLogger {
+class ScalaPlugin extends AbstractUIPlugin with PluginLogConfigurator with IResourceChangeListener with IElementChangedListener with IPartListener with HasLogger {
   ScalaPlugin.plugin = this
 
   final val HEADLESS_TEST  = "sdtcore.headless"
@@ -135,7 +136,7 @@ class ScalaPlugin extends AbstractUIPlugin with IResourceChangeListener with IEl
     val bundles = Option(Platform.getBundles(ScalaPlugin.plugin.libraryPluginId, null)).getOrElse(Array[Bundle]())
     logger.debug("[scalaLibBundle] Found %d bundles: %s".format(bundles.size, bundles.toList.mkString(", ")))
     bundles.find(b => b.getVersion().getMajor() == scalaCompilerBundleVersion.getMajor() && b.getVersion().getMinor() == scalaCompilerBundleVersion.getMinor()).getOrElse {
-      logger.error("Could not find a match for %s in %s. Using default.".format(scalaCompilerBundleVersion, bundles.toList.mkString(", ")), null)
+      eclipseLog.error("Could not find a match for %s in %s. Using default.".format(scalaCompilerBundleVersion, bundles.toList.mkString(", ")), null)
       Platform.getBundle(ScalaPlugin.plugin.libraryPluginId)
     }
   }

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaPresentationCompiler.scala

@@ -18,7 +18,8 @@ import scala.tools.nsc.util.{ BatchSourceFile, Position, SourceFile }
 import scala.tools.eclipse.javaelements.{
   ScalaCompilationUnit, ScalaIndexBuilder, ScalaJavaMapper, ScalaMatchLocator, ScalaStructureBuilder,
   ScalaOverrideIndicatorBuilder }
-import scala.tools.eclipse.util.{ Cached, EclipseFile, EclipseResource, HasLogger }
+import scala.tools.eclipse.util.{ Cached, EclipseFile, EclipseResource }
+import scala.tools.eclipse.logging.HasLogger
 import scala.tools.nsc.util.FailedInterrupt
 import scala.tools.nsc.symtab.Flags
 import scala.tools.eclipse.completion.CompletionProposal
@@ -137,11 +138,11 @@ class ScalaPresentationCompiler(project : ScalaProject, settings : Settings)
             None
 
           case e =>
-            logger.error("Error during askOption", e)
+            eclipseLog.error("Error during askOption", e)
             None
         }
       case e =>
-        logger.error("Error during askOption", e)
+        eclipseLog.error("Error during askOption", e)
         None
     }
 
@@ -197,7 +198,7 @@ class ScalaPresentationCompiler(project : ScalaProject, settings : Settings)
  }
 
   override def logError(msg : String, t : Throwable) =
-    logger.error(msg, t)
+    eclipseLog.error(msg, t)
 
   def destroy() {
     logger.info("shutting down presentation compiler on project: " + project)

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaProject.scala

@@ -24,7 +24,7 @@ import scala.tools.eclipse.properties.IDESettings
 import util.SWTUtils.asyncExec
 import EclipseUtils.workspaceRunnableIn
 import scala.tools.eclipse.properties.CompilerSettings
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 import scala.collection.mutable.ListBuffer
 import scala.actors.Actor
 import org.eclipse.jdt.core.IJarEntryResource
@@ -75,14 +75,14 @@ class ScalaProject private (val underlying: IProject) extends HasLogger {
       } catch {
         case ex @ MissingRequirementError(required) =>
           failedCompilerInitialization("could not find a required class: " + required)
-          logger.error(ex)
+          eclipseLog.error(ex)
           None
         case ex =>
           logger.info("Throwable when intializing presentation compiler!!! " + ex.getMessage)
           ex.printStackTrace()
           if (underlying.isOpen)
             failedCompilerInitialization("error initializing Scala compiler")
-          logger.error(ex)          
+          eclipseLog.error(ex)          
           None
       }
     }
@@ -227,7 +227,7 @@ class ScalaProject private (val underlying: IProject) extends HasLogger {
           }  
 
         case _ =>
-          logger.warning("Classpath computation encountered unknown entry: " + cpe)
+          logger.warn("Classpath computation encountered unknown entry: " + cpe)
       }
     }
     computeClasspath(javaProject, false)
@@ -361,7 +361,7 @@ class ScalaProject private (val underlying: IProject) extends HasLogger {
                     try {
                       cntnr.delete(true, monitor) // try again
                     } catch {
-                      case t => logger.error(t)
+                      case t => eclipseLog.error(t)
                     }
               }
             } else
@@ -370,7 +370,7 @@ class ScalaProject private (val underlying: IProject) extends HasLogger {
             try {
               file.delete(true, monitor)
             } catch {
-              case t => logger.error(t)
+              case t => eclipseLog.error(t)
             }
           case _ =>
         }
@@ -565,7 +565,7 @@ class ScalaProject private (val underlying: IProject) extends HasLogger {
           setting.tryToSetFromPropertyValue(value)
         }
       } catch {
-        case t: Throwable => logger.error("Unable to set setting '" + setting.name + "' to '" + value0 + "'", t)
+        case t: Throwable => eclipseLog.error("Unable to set setting '" + setting.name + "' to '" + value0 + "'", t)
       }
     }
 

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaSourceIndexer.scala

@@ -11,7 +11,7 @@ import org.eclipse.jdt.core.search.SearchDocument
 import org.eclipse.jdt.internal.core.search.indexing.AbstractIndexer
 import scala.tools.eclipse.javaelements.ScalaSourceFile
 import scala.tools.eclipse.contribution.weaving.jdt.indexerprovider.IIndexerFactory
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 class ScalaSourceIndexerFactory extends IIndexerFactory {
   override def createIndexer(document : SearchDocument) = new ScalaSourceIndexer(document);

org.scala-ide.sdt.core/src/scala/tools/eclipse/ScalaToggleBreakpointAdapter.scala

@@ -20,7 +20,7 @@ import org.eclipse.ui.IWorkbenchPart
 import scala.tools.eclipse.util.ReflectionUtils
 import scala.tools.eclipse.javaelements.ScalaClassElement
 import scala.tools.eclipse.javaelements.ScalaSourceTypeElement
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 class ScalaToggleBreakpointAdapter extends ToggleBreakpointAdapter with HasLogger { self =>
   import ScalaToggleBreakpointAdapterUtils._

org.scala-ide.sdt.core/src/scala/tools/eclipse/buildmanager/BuildReporter.scala

@@ -5,7 +5,8 @@ import scala.tools.eclipse.{EclipseBuildManager, TaskScanner, ScalaProject}
 import scala.tools.nsc.Settings
 import scala.tools.nsc.reporters.Reporter
 import scala.tools.nsc.util.{ Position, NoPosition }
-import scala.tools.eclipse.util.{ EclipseResource, FileUtils, HasLogger }
+import scala.tools.eclipse.util.{ EclipseResource, FileUtils}
+import scala.tools.eclipse.logging.HasLogger
 
 import scala.collection.mutable.ListBuffer
 

org.scala-ide.sdt.core/src/scala/tools/eclipse/buildmanager/refined/EclipseRefinedBuildManager.scala

@@ -11,7 +11,7 @@ import scala.tools.nsc.io.AbstractFile
 import scala.tools.nsc.reporters.Reporter
 import scala.tools.eclipse.util.{ EclipseResource, FileUtils }
 import org.eclipse.core.runtime.{ SubMonitor, IPath, Path }
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 class EclipseRefinedBuildManager(project: ScalaProject, settings0: Settings)
   extends RefinedBuildManager(settings0) with EclipseBuildManager with HasLogger {
@@ -82,7 +82,7 @@ class EclipseRefinedBuildManager(project: ScalaProject, settings0: Settings)
       case e =>
         hasErrors = true
         project.buildError(IMarker.SEVERITY_ERROR, "Error in Scala compiler: " + e.getMessage, null)
-        logger.error("Error in Scala compiler", e)
+        eclipseLog.error("Error in Scala compiler", e)
     }
     if (!hasErrors)
       pendingSources.clear

org.scala-ide.sdt.core/src/scala/tools/eclipse/buildmanager/sbtintegration/AnalysisCompile.scala

@@ -22,7 +22,7 @@ import scala.tools.eclipse.util.EclipseResource
 import java.io.File
 import org.eclipse.jdt.launching.JavaRuntime
 import org.eclipse.jdt.core.{ JavaCore, IJavaProject }
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 import scala.tools.eclipse.contribution.weaving.jdt.jcompiler.BuildManagerStore
 
 class AnalysisCompile (conf: BasicConfiguration, bm: EclipseSbtBuildManager, contr: Controller) extends HasLogger {
@@ -195,7 +195,7 @@ class AnalysisCompile (conf: BasicConfiguration, bm: EclipseSbtBuildManager, con
             null
 
           case ex =>
-            logger.error("Crash in the build compiler.", ex)
+            eclipseLog.error("Crash in the build compiler.", ex)
             reporter.log(SbtConverter.convertToSbt(NoPosition), "The SBT builder crashed while compiling your project. This is a bug in the Scala compiler or SBT. Check the Erorr Log for details. The error message is: " + ex.getMessage(), xsbti.Severity.Error)
             null
 

org.scala-ide.sdt.core/src/scala/tools/eclipse/buildmanager/sbtintegration/EclipseSbtBuildManager.scala

@@ -16,7 +16,7 @@ import sbt.compiler.{JavaCompiler}
 import sbt.{Process, ClasspathOptions}
 import scala.tools.eclipse.util.{ EclipseResource, FileUtils }
 import org.eclipse.core.resources.IResource
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 // The following code is based on sbt.AggressiveCompile
 // Copyright 2010 Mark Harrah
@@ -340,7 +340,7 @@ class EclipseSbtBuildManager(val project: ScalaProject, settings0: Settings)
   	      //ScalaPlugin.plugin.sbtScalaLib.get.toFile
   	      val e = new Exception("Cannot find Scala library on the classpath. Verify your build path!")
   	      project.buildError(IMarker.SEVERITY_ERROR, e.getMessage(), null)
-          logger.error("Error in Scala SBT builder", e)
+          eclipseLog.error("Error in Scala SBT builder", e)
   	      return
   	  }
   	  //val compJar = ScalaPlugin.plugin.sbtScalaCompiler
@@ -391,7 +391,7 @@ class EclipseSbtBuildManager(val project: ScalaProject, settings0: Settings)
       case e =>
         hasErrors = true
         project.buildError(IMarker.SEVERITY_ERROR, "Error in Scala compiler: " + e.getMessage, null)
-        logger.error("Error in Scala compiler", e)
+        eclipseLog.error("Error in Scala compiler", e)
     }
     if (!hasErrors)
       pendingSources.clear

org.scala-ide.sdt.core/src/scala/tools/eclipse/buildmanager/sbtintegration/SbtConf.scala

@@ -6,7 +6,7 @@ import sbt.{ ScalaInstance, Path }
 import xsbt.boot.{Launcher, Repository }
 import java.io.File
 import org.eclipse.core.resources.ResourcesPlugin
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 object ScalaCompilerConf {
     val LIBRARY_SUFFIX = "scala-library.jar"

org.scala-ide.sdt.core/src/scala/tools/eclipse/completion/ScalaCompletions.scala

@@ -6,7 +6,7 @@ import org.eclipse.jdt.core.search.{SearchEngine, IJavaSearchConstants, SearchPa
 import org.eclipse.jdt.core.IJavaElement
 import scala.collection.mutable
 import org.eclipse.core.runtime.NullProgressMonitor
-import scala.tools.eclipse.util.HasLogger
+import scala.tools.eclipse.logging.HasLogger
 
 /** Base class for Scala completions. No UI dependency, can be safely used in a
  *  headless testing environment.