--- a/mxtool/mx.py	Wed Jan 21 13:36:23 2015 +0100
+++ b/mxtool/mx.py	Wed Jan 21 13:55:37 2015 +0100
@@ -2,7 +2,7 @@
 #
 # ----------------------------------------------------------------------------------------------------
 #
-# Copyright (c) 2007, 2012, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -554,10 +554,17 @@
     """
     def annotation_processors_path(self):
         aps = [project(ap) for ap in self.annotation_processors()]
-        if len(aps):
-            return os.pathsep.join([ap.definedAnnotationProcessorsDist.path for ap in aps if ap.definedAnnotationProcessorsDist])
+        libAps = [dep for dep in self.all_deps([], includeLibs=True, includeSelf=False) if dep.isLibrary() and hasattr(dep, 'annotationProcessor') and getattr(dep, 'annotationProcessor').lower() == 'true']
+        if len(aps) + len(libAps):
+            return os.pathsep.join([ap.definedAnnotationProcessorsDist.path for ap in aps if ap.definedAnnotationProcessorsDist] + [lib.get_path(False) for lib in libAps])
         return None
 
+    def uses_annotation_processor_library(self):
+        for dep in self.all_deps([], includeLibs=True, includeSelf=False):
+            if dep.isLibrary() and hasattr(dep, 'annotationProcessor'):
+                return True
+        return False
+
     def update_current_annotation_processors_file(self):
         aps = self.annotation_processors()
         outOfDate = False
@@ -2444,7 +2451,10 @@
                     with open(jdtProperties) as fp:
                         origContent = fp.read()
                         content = origContent
-                        if args.jdt_warning_as_error:
+                        if self.proj.uses_annotation_processor_library():
+                            # unfortunately, the command line compiler doesn't let us ignore warnings for generated files only
+                            content = content.replace('=warning', '=ignore')
+                        elif args.jdt_warning_as_error:
                             content = content.replace('=warning', '=error')
                         if not args.jdt_show_task_tags:
                             content = content + '\norg.eclipse.jdt.core.compiler.problem.tasks=ignore'
@@ -3591,11 +3601,19 @@
             os.mkdir(srcDir)
         out.element('classpathentry', {'kind' : 'src', 'path' : src})
 
-    if len(p.annotation_processors()) > 0:
+    processorPath = p.annotation_processors_path()
+    if processorPath:
         genDir = p.source_gen_dir()
         if not exists(genDir):
             os.mkdir(genDir)
-        out.element('classpathentry', {'kind' : 'src', 'path' : 'src_gen'})
+        out.open('classpathentry', {'kind' : 'src', 'path' : 'src_gen'})
+        if p.uses_annotation_processor_library():
+            # ignore warnings produced by third-party annotation processors
+            out.open('attributes')
+            out.element('attribute', {'name' : 'ignore_optional_problems', 'value' : 'true'})
+            out.close('attributes')
+        out.close('classpathentry')
+
         if files:
             files.append(genDir)
 
@@ -3775,19 +3793,18 @@
     # copy a possibly modified file to the project's .settings directory
     for name, path in esdict.iteritems():
         # ignore this file altogether if this project has no annotation processors
-        if name == "org.eclipse.jdt.apt.core.prefs" and not len(p.annotation_processors()) > 0:
+        if name == "org.eclipse.jdt.apt.core.prefs" and not processorPath:
             continue
 
         with open(path) as f:
             content = f.read()
         content = content.replace('${javaCompliance}', str(p.javaCompliance))
-        if len(p.annotation_processors()) > 0:
+        if processorPath:
             content = content.replace('org.eclipse.jdt.core.compiler.processAnnotations=disabled', 'org.eclipse.jdt.core.compiler.processAnnotations=enabled')
         update_file(join(settingsDir, name), content)
         if files:
             files.append(join(settingsDir, name))
 
-    processorPath = p.annotation_processors_path()
     if processorPath:
         out = XMLDoc()
         out.open('factorypath')