Merge pull request #2175 from aschackmull/java/continue-in-false-loop

Java: Port C++ query cpp/continue-in-false-loop to Java.

java/ql/test/query-tests/ContinueInFalseLoop/A.java

@@ -0,0 +1,84 @@
+public class A {
+
+  public interface Cond {
+    boolean cond();
+  }
+
+  void test1(int x, Cond c) {
+    int i;
+
+    // --- do loops ---
+
+    do {
+      if (c.cond())
+        continue; // BAD
+      if (c.cond())
+        break;
+    } while (false);
+
+    do {
+      if (c.cond())
+        continue;
+      if (c.cond())
+        break;
+    } while (true);
+
+    do {
+      if (c.cond())
+        continue;
+      if (c.cond())
+        break;
+    } while (c.cond());
+
+    // --- while, for loops ---
+
+    while (false) {
+      if (c.cond())
+        continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply]
+      if (c.cond())
+        break;
+    }
+
+    for (i = 0; false; i++) {
+      if (c.cond())
+        continue; // GOOD [never reached, if the condition changed so it was then the result would no longer apply]
+      if (c.cond())
+        break;
+    }
+
+    // --- nested loops ---
+
+    do {
+      do {
+        if (c.cond())
+          continue; // BAD
+        if (c.cond())
+          break;
+      } while (false);
+      if (c.cond())
+        break;
+    } while (true);
+
+    do {
+      do {
+        if (c.cond())
+          continue; // GOOD
+        if (c.cond())
+          break;
+      } while (true);
+    } while (false);
+
+    do {
+      switch (x) {
+      case 1:
+        // do [1]
+        break; // break out of the switch
+      default:
+        // do [2]
+        // break out of the loop entirely, skipping [3]
+        continue; // BAD; labelled break is better
+      };
+      // do [3]
+    } while (false);
+  }
+}

java/ql/test/query-tests/ContinueInFalseLoop/ContinueInFalseLoop.expected

@@ -0,0 +1,3 @@
+| A.java:14:9:14:17 | stmt | This 'continue' never re-runs the loop - the $@ is always false. | A.java:17:14:17:18 | false | loop condition |
+| A.java:54:11:54:19 | stmt | This 'continue' never re-runs the loop - the $@ is always false. | A.java:57:16:57:20 | false | loop condition |
+| A.java:79:9:79:17 | stmt | This 'continue' never re-runs the loop - the $@ is always false. | A.java:82:14:82:18 | false | loop condition |

java/ql/test/query-tests/ContinueInFalseLoop/ContinueInFalseLoop.qlref

@@ -0,0 +1 @@
+Likely Bugs/Statements/ContinueInFalseLoop.ql