Merge pull request #2205 from rneatherway/java/hamcrest-nullness

Java: Respect Hamcrest assertThat(X, notNullValue())

java/ql/src/semmle/code/java/dataflow/Nullness.qll

@@ -143,11 +143,21 @@ private ControlFlowNode varDereference(SsaVariable v, VarAccess va) {
  * subsequent use, either by dereferencing it or by an assertion.
  */
 private ControlFlowNode ensureNotNull(SsaVariable v) {
-  result = varDereference(v, _) or
-  result.(AssertStmt).getExpr() = nullGuard(v, true, false) or
-  exists(AssertTrueMethod m | result = m.getACheck(nullGuard(v, true, false))) or
-  exists(AssertFalseMethod m | result = m.getACheck(nullGuard(v, false, false))) or
+  result = varDereference(v, _)
+  or
+  result.(AssertStmt).getExpr() = nullGuard(v, true, false)
+  or
+  exists(AssertTrueMethod m | result = m.getACheck(nullGuard(v, true, false)))
+  or
+  exists(AssertFalseMethod m | result = m.getACheck(nullGuard(v, false, false)))
+  or
   exists(AssertNotNullMethod m | result = m.getACheck(v.getAUse()))
+  or
+  exists(AssertThatMethod m, MethodAccess ma |
+    result = m.getACheck(v.getAUse()) and ma.getControlFlowNode() = result
+  |
+    ma.getAnArgument().(MethodAccess).getMethod().getName() = "notNullValue"
+  )
 }
 
 /**

java/ql/src/semmle/code/java/frameworks/Assertions.qll

@@ -11,7 +11,8 @@ newtype AssertKind =
   AssertKindTrue() or
   AssertKindFalse() or
   AssertKindNotNull() or
-  AssertKindFail()
+  AssertKindFail() or
+  AssertKindThat()
 
 private predicate assertionMethod(Method m, AssertKind kind) {
   exists(RefType junit |
@@ -27,6 +28,13 @@ private predicate assertionMethod(Method m, AssertKind kind) {
     m.hasName("fail") and kind = AssertKindFail()
   )
   or
+  exists(RefType hamcrest |
+    m.getDeclaringType() = hamcrest and
+    hamcrest.hasQualifiedName("org.hamcrest", "MatcherAssert")
+  |
+    m.hasName("assertThat") and kind = AssertKindThat()
+  )
+  or
   exists(RefType objects |
     m.getDeclaringType() = objects and
     objects.hasQualifiedName("java.util", "Objects")
@@ -82,6 +90,14 @@ class AssertFailMethod extends AssertionMethod {
   AssertFailMethod() { assertionMethod(this, AssertKindFail()) }
 }
 
+/**
+ * A method that asserts that its first argument has a property
+ * given by its second argument.
+ */
+class AssertThatMethod extends AssertionMethod {
+  AssertThatMethod() { assertionMethod(this, AssertKindThat()) }
+}
+
 /** A trivially failing assertion. That is, `assert false` or its equivalents. */
 predicate assertFail(BasicBlock bb, ControlFlowNode n) {
   bb = n.getBasicBlock() and

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

@@ -1,6 +1,8 @@
 import java.util.Iterator;
 import java.util.List;
 import static org.junit.Assert.*;
+import static org.hamcrest.core.IsNull.*;
+import static org.hamcrest.MatcherAssert.*;
 
 public class A {
   public void notTest() {
@@ -296,6 +298,12 @@ public class A {
     for (it = iter.iterator(); !!it.hasNext(); ) {}
   }
 
+  public void assertThatTest() {
+    Object assertThat_ok1 = maybe() ? null : new Object();
+    assertThat(assertThat_ok1, notNullValue());
+    assertThat_ok1.toString();
+  }
+
   private boolean m;
   A(boolean m) {
     this.m = m;

java/ql/test/query-tests/Nullness/B.java

@@ -120,7 +120,7 @@ public class B {
   }
 
   private Object mkMaybe() {
-    if (maybe) throw new Exception();
+    if (maybe) throw new RuntimeException();
     return new Object();
   }
 
@@ -267,7 +267,7 @@ public class B {
     }
     if(msg != null) {
       msg += "foobar";
-      throw new Exception(msg);
+      throw new RuntimeException(msg);
     }
     obj.hashCode(); // OK
   }
@@ -286,7 +286,7 @@ public class B {
 
     int[] b = maybe ? null : new int[iters];
     if (iters > 0 && (b == null || b.length < iters)) {
-      throw new Exception();
+      throw new RuntimeException();
     }
     for (int i = 0; i < iters; ++i) {
       b[i] = 0; // NPE - false positive

java/ql/test/query-tests/Nullness/C.java

@@ -87,7 +87,7 @@ public class C {
         vals[0] = 0; // OK
         break;
       default:
-        throw new Exception();
+        throw new RuntimeException();
     }
   }
 

java/ql/test/query-tests/Nullness/NullAlways.expected

@@ -1,15 +1,15 @@
-| A.java:13:7:13:9 | not | Variable $@ is always null here. | A.java:11:5:11:22 | Object not | not |
-| A.java:95:18:95:36 | synchronized_always | Variable $@ is always null here. | A.java:94:5:94:38 | Object synchronized_always | synchronized_always |
-| A.java:159:26:159:34 | do_always | Variable $@ is always null here. | A.java:157:5:157:28 | String do_always | do_always |
-| A.java:165:26:165:34 | do_maybe1 | Variable $@ is always null here. | A.java:163:5:163:28 | String do_maybe1 | do_maybe1 |
-| A.java:185:26:185:37 | while_always | Variable $@ is always null here. | A.java:183:5:183:31 | String while_always | while_always |
-| A.java:205:26:205:34 | if_always | Variable $@ is always null here. | A.java:203:5:203:28 | String if_always | if_always |
-| A.java:221:24:221:29 | for_ok | Variable $@ is always null here. | A.java:217:5:217:19 | String for_ok | for_ok |
-| A.java:224:26:224:35 | for_always | Variable $@ is always null here. | A.java:223:10:223:33 | String for_always | for_always |
-| A.java:234:5:234:14 | array_null | Variable $@ is always null here. | A.java:233:5:233:28 | int[] array_null | array_null |
-| A.java:246:24:246:34 | arrayaccess | Variable $@ is always null here. | A.java:242:5:242:29 | int[] arrayaccess | arrayaccess |
-| A.java:247:24:247:34 | fieldaccess | Variable $@ is always null here. | A.java:243:5:243:32 | String[] fieldaccess | fieldaccess |
-| A.java:248:24:248:35 | methodaccess | Variable $@ is always null here. | A.java:244:5:244:31 | Object methodaccess | methodaccess |
-| A.java:262:21:262:30 | for_always | Variable $@ is always null here. | A.java:261:5:261:35 | List<String> for_always | for_always |
-| A.java:264:24:264:33 | for_always | Variable $@ is always null here. | A.java:261:5:261:35 | List<String> for_always | for_always |
+| A.java:15:7:15:9 | not | Variable $@ is always null here. | A.java:13:5:13:22 | Object not | not |
+| A.java:97:18:97:36 | synchronized_always | Variable $@ is always null here. | A.java:96:5:96:38 | Object synchronized_always | synchronized_always |
+| A.java:161:26:161:34 | do_always | Variable $@ is always null here. | A.java:159:5:159:28 | String do_always | do_always |
+| A.java:167:26:167:34 | do_maybe1 | Variable $@ is always null here. | A.java:165:5:165:28 | String do_maybe1 | do_maybe1 |
+| A.java:187:26:187:37 | while_always | Variable $@ is always null here. | A.java:185:5:185:31 | String while_always | while_always |
+| A.java:207:26:207:34 | if_always | Variable $@ is always null here. | A.java:205:5:205:28 | String if_always | if_always |
+| A.java:223:24:223:29 | for_ok | Variable $@ is always null here. | A.java:219:5:219:19 | String for_ok | for_ok |
+| A.java:226:26:226:35 | for_always | Variable $@ is always null here. | A.java:225:10:225:33 | String for_always | for_always |
+| A.java:236:5:236:14 | array_null | Variable $@ is always null here. | A.java:235:5:235:28 | int[] array_null | array_null |
+| A.java:248:24:248:34 | arrayaccess | Variable $@ is always null here. | A.java:244:5:244:29 | int[] arrayaccess | arrayaccess |
+| A.java:249:24:249:34 | fieldaccess | Variable $@ is always null here. | A.java:245:5:245:32 | String[] fieldaccess | fieldaccess |
+| A.java:250:24:250:35 | methodaccess | Variable $@ is always null here. | A.java:246:5:246:31 | Object methodaccess | methodaccess |
+| A.java:264:21:264:30 | for_always | Variable $@ is always null here. | A.java:263:5:263:35 | List<String> for_always | for_always |
+| A.java:266:24:266:33 | for_always | Variable $@ is always null here. | A.java:263:5:263:35 | List<String> for_always | for_always |
 | B.java:304:7:304:9 | ioe | Variable $@ is always null here. | B.java:297:5:297:25 | Exception ioe | ioe |

java/ql/test/query-tests/Nullness/NullMaybe.expected

@@ -1,9 +1,9 @@
-| A.java:46:5:46:21 | assertNotNull_ok3 | Variable $@ may be null here because of $@ assignment. | A.java:44:5:44:61 | Object assertNotNull_ok3 | assertNotNull_ok3 | A.java:44:12:44:60 | assertNotNull_ok3 | this |
-| A.java:170:26:170:33 | do_maybe | Variable $@ may be null here because of $@ assignment. | A.java:168:5:168:25 | String do_maybe | do_maybe | A.java:171:7:171:21 | ...=... | this |
-| A.java:191:26:191:36 | while_maybe | Variable $@ may be null here because of $@ assignment. | A.java:189:5:189:28 | String while_maybe | while_maybe | A.java:192:7:192:24 | ...=... | this |
-| A.java:213:24:213:31 | if_maybe | Variable $@ may be null here because of $@ assignment. | A.java:209:5:209:25 | String if_maybe | if_maybe | A.java:211:7:211:21 | ...=... | this |
-| A.java:228:26:228:34 | for_maybe | Variable $@ may be null here because of $@ assignment. | A.java:227:10:227:30 | String for_maybe | for_maybe | A.java:227:35:227:50 | ...=... | this |
-| A.java:271:24:271:32 | for_maybe | Variable $@ may be null here because of $@ assignment. | A.java:266:5:266:63 | List<String> for_maybe | for_maybe | A.java:269:7:269:22 | ...=... | this |
+| A.java:48:5:48:21 | assertNotNull_ok3 | Variable $@ may be null here because of $@ assignment. | A.java:46:5:46:61 | Object assertNotNull_ok3 | assertNotNull_ok3 | A.java:46:12:46:60 | assertNotNull_ok3 | this |
+| A.java:172:26:172:33 | do_maybe | Variable $@ may be null here because of $@ assignment. | A.java:170:5:170:25 | String do_maybe | do_maybe | A.java:173:7:173:21 | ...=... | this |
+| A.java:193:26:193:36 | while_maybe | Variable $@ may be null here because of $@ assignment. | A.java:191:5:191:28 | String while_maybe | while_maybe | A.java:194:7:194:24 | ...=... | this |
+| A.java:215:24:215:31 | if_maybe | Variable $@ may be null here because of $@ assignment. | A.java:211:5:211:25 | String if_maybe | if_maybe | A.java:213:7:213:21 | ...=... | this |
+| A.java:230:26:230:34 | for_maybe | Variable $@ may be null here because of $@ assignment. | A.java:229:10:229:30 | String for_maybe | for_maybe | A.java:229:35:229:50 | ...=... | this |
+| A.java:273:24:273:32 | for_maybe | Variable $@ may be null here because of $@ assignment. | A.java:268:5:268:63 | List<String> for_maybe | for_maybe | A.java:271:7:271:22 | ...=... | this |
 | B.java:16:5:16:9 | param | Variable $@ may be null here because of $@ null argument. | B.java:15:23:15:34 | param | param | B.java:11:13:11:16 | null | this |
 | B.java:23:5:23:9 | param | Variable $@ may be null here as suggested by $@ null guard. | B.java:19:23:19:34 | param | param | B.java:20:9:20:21 | ... != ... | this |
 | B.java:57:7:57:8 | o7 | Variable $@ may be null here because of $@ assignment. | B.java:52:5:52:34 | Object o7 | o7 | B.java:52:12:52:33 | o7 | this |

java/ql/test/query-tests/Nullness/options

@@ -1 +1 @@
-//semmle-extractor-options: --javac-args -cp ${testdir}/../../stubs/junit-4.11:${testdir}/../../stubs/junit-jupiter-api-5.2.0
+//semmle-extractor-options: --javac-args -cp ${testdir}/../../stubs/junit-4.11:${testdir}/../../stubs/hamcrest-2.2:${testdir}/../../stubs/junit-jupiter-api-5.2.0

java/ql/test/stubs/hamcrest-2.2/LICENSE.txt

@@ -0,0 +1,27 @@
+BSD License
+
+Copyright (c) 2000-2015 www.hamcrest.org
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+Redistributions of source code must retain the above copyright notice, this list of
+conditions and the following disclaimer. Redistributions in binary form must reproduce
+the above copyright notice, this list of conditions and the following disclaimer in
+the documentation and/or other materials provided with the distribution.
+
+Neither the name of Hamcrest nor the names of its contributors may be used to endorse
+or promote products derived from this software without specific prior written
+permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGE.

java/ql/test/stubs/hamcrest-2.2/org/hamcrest/MatcherAssert.java

@@ -0,0 +1,14 @@
+package org.hamcrest;
+
+
+public class MatcherAssert {
+    public static <T> void assertThat(T actual, Object matcher) {
+        assertThat("", actual, matcher);
+    }
+    
+    public static <T> void assertThat(String reason, T actual, Object matcher) {
+    }
+    
+    public static void assertThat(String reason, boolean assertion) {
+    }
+}

java/ql/test/stubs/hamcrest-2.2/org/hamcrest/core/IsNull.java

@@ -0,0 +1,13 @@
+package org.hamcrest.core;
+
+public class IsNull {
+
+    public static Object notNullValue() {
+        return new String();
+    }
+
+    public static <T> Object notNullValue(Class<T> type) {
+        return new String();
+    }
+}
+