Add jt spotbugs and mx ruby_spotbugs to run more SpotBugs checks

Author: eregon

mx.truffleruby/mx_truffleruby.py

@@ -13,6 +13,7 @@
 import mx
 import mx_sdk
 import mx_subst
+import mx_spotbugs
 
 if 'RUBY_BENCHMARKS' in os.environ:
     import mx_truffleruby_benchmark  # pylint: disable=unused-import
@@ -160,6 +161,14 @@ def ruby_testdownstream_sulong(args):
     jt('test', 'mri', '--all-sulong')
     jt('test', 'cexts')
 
+def ruby_spotbugs(args):
+    """Run SpotBugs with custom options to detect more issues"""
+    filters = join(root, 'mx.truffleruby', 'spotbugs-filters.xml')
+    spotbugsArgs = ['-textui', '-low', '-longBugCodes', '-include', filters]
+    if mx.is_interactive():
+        spotbugsArgs.append('-progress')
+    mx_spotbugs.spotbugs(args, spotbugsArgs)
+
 def verify_ci(args):
     """Verify CI configuration"""
     mx.verify_ci(args, mx.suite('truffle'), _suite, 'common.json')
@@ -247,5 +256,6 @@ def verify_ci(args):
     'ruby_testdownstream_aot': [ruby_testdownstream_aot, 'aot_bin'],
     'ruby_testdownstream_hello': [ruby_testdownstream_hello, ''],
     'ruby_testdownstream_sulong': [ruby_testdownstream_sulong, ''],
+    'ruby_spotbugs': [ruby_spotbugs, ''],
     'verify-ci' : [verify_ci, '[options]'],
 })

mx.truffleruby/spotbugs-filters.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<FindBugsFilter>
+  <Match>
+    <Package name="~org\.truffleruby.*" />
+    <Not>
+      <Or>
+        <!-- These are not worth fixing -->
+        <Bug pattern="MS_PKGPROTECT" />
+        <Bug pattern="MS_MUTABLE_ARRAY" />
+        <Bug pattern="MS_MUTABLE_COLLECTION" />
+        <Bug pattern="SF_SWITCH_NO_DEFAULT" />
+        <Bug pattern="RI_REDUNDANT_INTERFACES" />
+        <!-- Intentional -->
+        <Bug pattern="BC_UNCONFIRMED_CAST" />
+        <Bug pattern="BC_UNCONFIRMED_CAST_OF_RETURN_VALUE" />
+        <Bug pattern="DM_EXIT" />
+        <Bug pattern="DM_GC" />
+        <Bug pattern="EI_EXPOSE_REP" />
+        <Bug pattern="EI_EXPOSE_REP2" />
+        <Bug pattern="FE_FLOATING_POINT_EQUALITY" />
+      </Or>
+    </Not>
+  </Match>
+</FindBugsFilter>

tool/jt.rb

@@ -2271,6 +2271,10 @@ def checkstyle
     end
   end
 
+  def spotbugs
+    mx 'ruby_spotbugs'
+  end
+
   module Formatting
     extend self
 
@@ -2466,7 +2470,7 @@ def lint(*args)
     # TODO (pitr-ch 11-Aug-2019): consider running all tasks in the `mx gate --tags fullbuild`
     #  - includes verifylibraryurls though
     #  - building with jdt in the ci definition could be dropped since fullbuild builds with JDT
-    mx 'spotbugs' unless fast
+    spotbugs unless fast
 
     mx 'verify-ci' if changed['.py']