QL: Merge pull request #95 from github/tausbn/add-override-test

Add test for `override`

Author: tausbn

ql/src/codeql_ql/ast/internal/Predicate.qll

@@ -153,7 +153,9 @@ module PredConsistency {
       strictcount(PredicateOrBuiltin p0 |
         resolveCall(call, p0) and
         // aliases are expected to resolve to multiple.
-        not exists(p0.(ClasslessPredicate).getAlias())
+        not exists(p0.(ClasslessPredicate).getAlias()) and
+        // overridden predicates may have multiple targets
+        not p0.(ClassPredicate).isOverride()
       ) and
     c > 1 and
     resolveCall(call, p)

ql/test/callgraph/Overrides.qll

@@ -0,0 +1,30 @@
+import ql
+
+class Foo extends int {
+  Foo() { this in [1, 2, 3] }
+
+  int bar() { result = this }
+
+  predicate baz(int i) { i = this.bar() }
+}
+
+class Bar extends Foo {
+  Bar() { this = [1, 2] }
+
+  override int bar() { result = 10 * this }
+
+  override predicate baz(int i) { i = this.bar() }
+}
+
+class Baz extends Foo {
+  Baz() { this = 1 }
+
+  override int bar() { result = 100 * this }
+
+  override predicate baz(int i) { i = this.bar() }
+}
+
+query predicate test(Foo f, int i, int j) {
+  f.bar() = i and
+  f.baz(j)
+}

ql/test/callgraph/callgraph.expected

@@ -9,6 +9,13 @@ getTarget
 | Foo.qll:31:5:31:12 | PredicateCall | Foo.qll:24:3:24:32 | ClasslessPredicate alias0 |
 | Foo.qll:36:36:36:65 | MemberCall | file://:0:0:0:0 | replaceAll |
 | Foo.qll:38:39:38:67 | MemberCall | file://:0:0:0:0 | regexpCapture |
+| Overrides.qll:8:30:8:39 | MemberCall | Overrides.qll:6:3:6:29 | ClassPredicate bar |
+| Overrides.qll:16:39:16:48 | MemberCall | Overrides.qll:6:3:6:29 | ClassPredicate bar |
+| Overrides.qll:16:39:16:48 | MemberCall | Overrides.qll:14:12:14:43 | ClassPredicate bar |
+| Overrides.qll:24:39:24:48 | MemberCall | Overrides.qll:6:3:6:29 | ClassPredicate bar |
+| Overrides.qll:24:39:24:48 | MemberCall | Overrides.qll:22:12:22:44 | ClassPredicate bar |
+| Overrides.qll:28:3:28:9 | MemberCall | Overrides.qll:6:3:6:29 | ClassPredicate bar |
+| Overrides.qll:29:3:29:10 | MemberCall | Overrides.qll:8:3:8:41 | ClassPredicate baz |
 | packs/src/SrcThing.qll:4:3:4:8 | PredicateCall | packs/lib/LibThing/Foo.qll:1:1:1:30 | ClasslessPredicate foo |
 | packs/src/SrcThing.qll:5:3:5:8 | PredicateCall | packs/src/SrcThing.qll:8:1:8:30 | ClasslessPredicate bar |
 dependsOn