Add QL for ::class expression, and add test

tamasvajk · igfoo · commit 9889f49560cc · 2022-05-10T18:45:58.000+01:00
diff --git a/java/ql/lib/semmle/code/java/Expr.qll b/java/ql/lib/semmle/code/java/Expr.qll
@@ -2143,9 +2143,7 @@ class WhenExpr extends Expr, @whenexpr {
   override string getAPrimaryQlClass() { result = "WhenExpr" }
 
   /** Gets the `i`th branch. */
-  WhenBranch getBranch(int i) {
-    when_branch(result, this, i)
-  }
+  WhenBranch getBranch(int i) { when_branch(result, this, i) }
 }
 
 /** A Kotlin `when` branch. */
@@ -2163,3 +2161,13 @@ class WhenBranch extends Top, @whenbranch {
 
   override string getAPrimaryQlClass() { result = "WhenBranch" }
 }
+
+/** A Kotlin `::class` expression. */
+class ClassExpr extends Expr, @getclassexpr {
+  /** Gets the expression whose class is being returned. */
+  Expr getExpr() { result.isNthChildOf(this, 0) }
+
+  override string toString() { result = "::class" }
+
+  override string getAPrimaryQlClass() { result = "ClassExpr" }
+}
diff --git a/java/ql/test/kotlin/library-tests/exprs/exprs.expected b/java/ql/test/kotlin/library-tests/exprs/exprs.expected
@@ -41,12 +41,15 @@
 | exprs.kt:46:12:46:14 | 123 | IntegerLiteral |
 | exprs.kt:46:12:46:20 | ... + ... | AddExpr |
 | exprs.kt:46:18:46:20 | 456 | IntegerLiteral |
+| exprs.kt:50:13:50:16 | true | BooleanLiteral |
+| exprs.kt:50:13:50:23 | ::class | ClassExpr |
 | file://:0:0:0:0 | b1 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | b2 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | b6 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | b7 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | b8 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | c | LocalVariableDeclExpr |
+| file://:0:0:0:0 | d | LocalVariableDeclExpr |
 | file://:0:0:0:0 | i1 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | i2 | LocalVariableDeclExpr |
 | file://:0:0:0:0 | i3 | LocalVariableDeclExpr |
diff --git a/java/ql/test/kotlin/library-tests/exprs/exprs.kt b/java/ql/test/kotlin/library-tests/exprs/exprs.kt
@@ -46,3 +46,6 @@ TODO
     return 123 + 456
 }
 
+fun getClass() {
+    val d = true::class
+}

Original file line number	Diff line number	Diff line change
`@@ -46,3 +46,6 @@ TODO`
`46`	`46`	`return 123 + 456`
`47`	`47`	`}`
`48`	`48`
	`49`	`+fun getClass() {`
	`50`	`+ val d = true::class`
	`51`	`+}`