Handle Pattern.compile(String, int) with two formal parameters

checker/src/main/java/org/checkerframework/checker/regex/RegexAnnotatedTypeFactory.java

@@ -112,6 +112,14 @@ public class RegexAnnotatedTypeFactory extends BaseAnnotatedTypeFactory {
   private final ExecutableElement patternCompile =
       TreeUtils.getMethod("java.util.regex.Pattern", "compile", 1, processingEnv);
 
+  /**
+   * The Pattern.compile method that takes two formal parameters (second one is flags).
+   *
+   * @see java.util.regex.Pattern#compile(String, int)
+   */
+  private final ExecutableElement patternCompile2 =
+      TreeUtils.getMethod("java.util.regex.Pattern", "compile", 2, processingEnv);
+
   /**
    * Create a new RegexAnnotatedTypeFactory.
    *
@@ -416,8 +424,8 @@ public Void visitCompoundAssignment(CompoundAssignmentTree node, AnnotatedTypeMi
      */
     @Override
     public Void visitMethodInvocation(MethodInvocationTree tree, AnnotatedTypeMirror type) {
-      // TODO: Also get this to work with 2 argument Pattern.compile.
-      if (TreeUtils.isMethodInvocation(tree, patternCompile, processingEnv)) {
+      if (TreeUtils.isMethodInvocation(tree, patternCompile, processingEnv)
+          || TreeUtils.isMethodInvocation(tree, patternCompile2, processingEnv)) {
         ExpressionTree arg0 = tree.getArguments().get(0);
 
         final AnnotatedTypeMirror argType = getAnnotatedType(arg0);

checker/tests/regex/GroupCounts.java

@@ -28,18 +28,25 @@ void testGroupCount() {
 
   void testPatternCompileGroupCount(@Regex String r, @Regex(3) String r3, @Regex(5) String r5) {
     @Regex(5) Pattern p1 = Pattern.compile(r5);
+    @Regex(5) Pattern p1a = Pattern.compile(r5, 0);
     @Regex Pattern p2 = Pattern.compile(r5);
     @Regex Pattern p3 = Pattern.compile(r);
 
     // :: error: (assignment)
     @Regex(6) Pattern p4 = Pattern.compile(r5); // error
     // :: error: (assignment)
+    @Regex(6) Pattern p4a = Pattern.compile(r5, 0); // error
+    // :: error: (assignment)
     @Regex(6) Pattern p5 = Pattern.compile(r3); // error
+    // :: error: (assignment)
+    @Regex(6) Pattern p5a = Pattern.compile(r3, 0); // error
 
     // Make sure Pattern.compile still works when passed an @UnknownRegex String
     // that's actually a regex, with the warning suppressed.
     @SuppressWarnings("regex:argument")
     Pattern p6 = Pattern.compile("(" + r + ")");
+    @SuppressWarnings("regex:argument")
+    Pattern p6a = Pattern.compile("(" + r + ")", 0);
   }
 
   void testConcatenationGroupCount(@Regex String r, @Regex(3) String r3, @Regex(5) String r5) {