Add statement-on-same-line-as-multi-line-statement-end.ql

Author: Marcono1234

codeql-custom-queries-java/queries/likely-bugs/statement-on-same-line-as-multi-line-statement-end.ql

@@ -0,0 +1,80 @@
+/**
+ * Finds statements which start on the same line as the end of a multi-line statement.
+ * This might indicate broken formatting which can make the code difficult to read,
+ * or it might indicate a logic error, e.g. a separate `if` statement instead of
+ * `else if`:
+ * ```java
+ * if (conditionA()) {
+ *     ...
+ * } if (conditionB()) {
+ * //^ was supposed to be `else if`
+ *    ...
+ * }
+ * ```
+ * 
+ * @kind problem
+ */
+
+import java
+
+from Stmt first, Location firstLocation, Stmt second, Location secondLocation
+where
+    // This also excludes implicit statements in lambdas which are compared without statement outside of it
+    first.getEnclosingCallable() = second.getEnclosingCallable()
+    and firstLocation = first.getLocation()
+    and secondLocation = second.getLocation()
+    // Make sure both are in the same file to prevent false positives when CodeQL has for some reason extracted
+    // different files with the same classes
+    and firstLocation.getFile() = secondLocation.getFile()
+    and firstLocation.getEndLine() = secondLocation.getStartLine()
+    and firstLocation.getEndColumn() < secondLocation.getStartColumn()
+    // To reduce false positives only consider statements spanning over more than one line
+    and firstLocation.getStartLine() < firstLocation.getEndLine()
+    // Ignore all kinds of statements which intentionally start on the same line
+    and not (
+        first.getParent+() = second
+        or second.getParent+() = first
+        or first instanceof SwitchCase
+        // Empty statement is already covered by other queries
+        or second instanceof EmptyStmt
+        // Ignore false positives caused implicit parent constructor invocations
+        or second = any(Callable c).getBody()
+        // Ignore implicit statements when declaring enum constants
+        or any(EnumConstant c).getAnAccess().(FieldWrite).getAnEnclosingStmt() = second
+        // Ignore if statements where both statements can be a block without either being the parent of the other
+        or exists(IfStmt ifStmt |
+            first = ifStmt.getThen()
+            and (
+                second = ifStmt.getElse()
+                or second.getParent() = ifStmt.getElse()
+            )
+        )
+        // Ignore try statements where both statements can be a block without either being the parent of the other
+        or exists(TryStmt tryStmt |
+            first = tryStmt.getBlock()
+            or first = tryStmt.getACatchClause().getBlock()
+        |
+            second = tryStmt.getACatchClause()
+            // Use getParent() to also consider catch block statements at the same line as catch clause
+            or second.getParent*() = tryStmt.getACatchClause().getBlock()
+            or second = tryStmt.getFinally()
+        )
+        // Ignore try resource variable declaration
+        or exists(TryStmt tryStmt |
+            first = tryStmt.getAResourceDecl()
+        |
+            second = tryStmt.getBlock()
+            or second = tryStmt.getAResourceDecl()
+        )
+        // Ignore jump statments, they are probably not as irritating if one the same line
+        or second instanceof JumpStmt
+        // Ignore single statement in block
+        or any(SingletonBlock s).getStmt() = second.(ExprStmt)
+        // Avoid duplicate results for statements with block
+        or any(IfStmt s).getThen() = second
+        or any(LoopStmt s).getBody() = second
+        or any(TryStmt s).getBlock() = second
+    )
+    // Ignore Kotlin source code for now, the cases to ignore defined above don't seem to work there properly
+    and not first.getCompilationUnit().isKotlinSourceFile()
+select second, "Starts on the same line as end of $@", first, "this statement"