id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
12472	Java 8: Use error-prone in build	simon04	Don-vip	"[http://errorprone.info/ Error-prone] aims at identifying issues at compile time. Running it on the current code base reveals:

{{{
compile:
    [javac] Compiling 434 source files to /home/simon/src/josm.svngit/build
    [javac] Note: /home/simon/src/josm.svngit/src/oauth/signpost/AbstractOAuthProvider.java uses or overrides a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: Some input files use unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
    [javac] Compiling 60 source files to /home/simon/src/josm.svngit/build
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java:305: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
    [javac]             synchronized (mapMarkerList) {
    [javac]                          ^
    [javac]     (see http://errorprone.info/bugpattern/SynchronizeOnNonFinalField)
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java:319: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
    [javac]             synchronized (mapRectangleList) {
    [javac]                          ^
    [javac]     (see http://errorprone.info/bugpattern/SynchronizeOnNonFinalField)
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java:334: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
    [javac]             synchronized (mapPolygonList) {
    [javac]                          ^
    [javac]     (see http://errorprone.info/bugpattern/SynchronizeOnNonFinalField)
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java:653: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
    [javac]             synchronized (mapPolygonList) {
    [javac]                          ^
    [javac]     (see http://errorprone.info/bugpattern/SynchronizeOnNonFinalField)
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java:662: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
    [javac]             synchronized (mapRectangleList) {
    [javac]                          ^
    [javac]     (see http://errorprone.info/bugpattern/SynchronizeOnNonFinalField)
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/gui/jmapviewer/JMapViewer.java:671: warning: [SynchronizeOnNonFinalField] Synchronizing on non-final fields is not safe: if the field is ever updated, different threads may end up locking on different objects.
    [javac]             synchronized (mapMarkerList) {
    [javac]                          ^
    [javac]     (see http://errorprone.info/bugpattern/SynchronizeOnNonFinalField)
    [javac] 6 warnings
    [javac] Compiling 1290 source files to /home/simon/src/josm.svngit/build
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/josm/data/osm/Storage.java:414: warning: [NonAtomicVolatileUpdate] This update of a volatile variable is non-atomic
    [javac]             modCount++;
    [javac]                     ^
    [javac]     (see http://errorprone.info/bugpattern/NonAtomicVolatileUpdate)
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/josm/gui/SideButton.java:59: warning: [StringEquality] String comparison using reference equality instead of value equality
    [javac]                     if (evt.getPropertyName() == javax.swing.Action.SMALL_ICON) {
    [javac]                                               ^
    [javac]     (see http://errorprone.info/bugpattern/StringEquality)
    [javac]   Did you mean 'if (javax.swing.Action.SMALL_ICON.equals(evt.getPropertyName())) {'?
    [javac] /home/simon/src/josm.svngit/src/org/openstreetmap/josm/io/NmeaReader.java:54: warning: [NonOverridingEquals] equals method doesn't override Object.equals; enum instances can safely be compared by reference equality, so please delete this
    [javac]         public boolean equals(String type) {
    [javac]                        ^
    [javac]     (see http://errorprone.info/bugpattern/NonOverridingEquals)
    [javac]   Did you mean to remove this line?
    [javac] 3 warnings
     [copy] Copying 1 file to /home/simon/src/josm.svngit/build
}}}

To integrate it, the following modifications on `build.xml` are required:
{{{#!diff
diff --git a/build.xml b/build.xml
index bd7e95c..019fd16 100644
--- a/build.xml
+++ b/build.xml
@@ -225,8 +225,12 @@ Build-Date: ${build.tstamp}
             <exclude name=""org/apache/commons/logging/impl/ServletContextCleaner.java""/>
         </javac>
         <!-- JMapViewer -->
-        <javac sourcepath="""" srcdir=""${src.dir}"" excludes=""com/**,oauth/**,org/apache/commons/**,org/glassfish/**,org/openstreetmap/gui/jmapviewer/Demo.java,org/openstreetmap/josm/**,JOSM.java,gnu/**"" 
+        <javac compiler=""com.google.errorprone.ErrorProneAntCompilerAdapter""
+            sourcepath="""" srcdir=""${src.dir}"" excludes=""com/**,oauth/**,org/apache/commons/**,org/glassfish/**,org/openstreetmap/gui/jmapviewer/Demo.java,org/openstreetmap/josm/**,JOSM.java,gnu/**""
             destdir=""build"" target=""1.7"" source=""1.7"" debug=""on"" includeantruntime=""false"" createMissingPackageInfoClass=""false"" encoding=""UTF-8"">
+            <compilerclasspath>
+              <pathelement location=""./error_prone_ant-2.0.8.jar""/>
+            </compilerclasspath>
             <compilerarg value=""-Xlint:cast""/>
             <compilerarg value=""-Xlint:deprecation""/>
             <compilerarg value=""-Xlint:dep-ann""/>
@@ -242,8 +246,12 @@ Build-Date: ${build.tstamp}
             <compilerarg value=""-XDignore.symbol.file""/>
         </javac>
         <!-- JOSM -->
-        <javac sourcepath="""" srcdir=""${src.dir}"" excludes=""com/**,oauth/**,org/apache/commons/**,org/glassfish/**,org/openstreetmap/gui/jmapviewer/Demo.java"" 
+        <javac compiler=""com.google.errorprone.ErrorProneAntCompilerAdapter""
+            sourcepath="""" srcdir=""${src.dir}"" excludes=""com/**,oauth/**,org/apache/commons/**,org/glassfish/**,org/openstreetmap/gui/jmapviewer/Demo.java""
             destdir=""build"" target=""1.7"" source=""1.7"" debug=""on"" includeantruntime=""false"" createMissingPackageInfoClass=""false"" encoding=""UTF-8"">
+            <compilerclasspath>
+              <pathelement location=""./error_prone_ant-2.0.8.jar""/>
+            </compilerclasspath>
             <compilerarg value=""-Xlint:cast""/>
             <compilerarg value=""-Xlint:deprecation""/>
             <compilerarg value=""-Xlint:dep-ann""/>
}}}

Shall we add this to our build process?"	enhancement	closed	normal	16.07	Core		fixed	build error prone ant java8	Don-vip bastiK