checkpoint: A0-1-2

Author: jeongsoolee09

cpp/autosar/src/rules/A0-1-2/UnusedReturnValue.ql

@@ -18,6 +18,16 @@ import cpp
 import codingstandards.cpp.autosar
 import semmle.code.cpp.dataflow.DataFlow
 
+// Type isEdgeCase(Expr expr) {
+//   // 1. c-style casts to void.
+//      expr.(CStyleCast).getUnderlyingType()
+//   // 2. Assignment to std::ignore
+// }
+
+from CStyleCast expr
+where any()
+select expr, expr.getType()
+
 /*
  * This query performs a simple syntactic check to ensure that the return value of the function is
  * not completely ignored. This matches the examples given in the rule, although the text itself is
@@ -26,21 +36,21 @@ import semmle.code.cpp.dataflow.DataFlow
  * access of `ret_val`. However, such a case _would_ be flagged by A0-1-1 - Useless assignment.
  */
 
-from FunctionCall fc, Function f
-where
-  not isExcluded(fc, DeadCodePackage::unusedReturnValueQuery()) and
-  // Find function calls in `ExprStmt`s, which indicate the return value is ignored
-  fc.getParent() instanceof ExprStmt and
-  // Ignore calls to void functions, which don't return values
-  not fc.getUnderlyingType() instanceof VoidType and
-  // Get the function target
-  f = fc.getTarget() and
-  // Overloaded (i.e. user defined) operators should behave in the same way as built-in operators,
-  // so the rule does not require the use of the return value
-  not f instanceof Operator and
-  // Exclude cases where the function call is generated within a macro, as the user of the macro is
-  // not necessarily able to address thoes results
-  not fc.isAffectedByMacro() and
-  // Rule allows disabling this rule where a static_cast<void> is applied
-  not fc.getExplicitlyConverted().(StaticCast).getActualType() instanceof VoidType
-select fc, "Return value from call to $@ is unused.", f, f.getName()
+// from FunctionCall fc, Function f
+// where
+//   not isExcluded(fc, DeadCodePackage::unusedReturnValueQuery()) and
+//   // Find function calls in `ExprStmt`s, which indicate the return value is ignored
+//   fc.getParent() instanceof ExprStmt and
+//   // Ignore calls to void functions, which don't return values
+//   not fc.getUnderlyingType() instanceof VoidType and
+//   // Get the function target
+//   f = fc.getTarget() and
+//   // Overloaded (i.e. user defined) operators should behave in the same way as built-in operators,
+//   // so the rule does not require the use of the return value
+//   not f instanceof Operator and
+//   // Exclude cases where the function call is generated within a macro, as the user of the macro is
+//   // not necessarily able to address thoes results
+//   not fc.isAffectedByMacro() and
+//   // Rule allows disabling this rule where a static_cast<void> is applied
+//   not fc.getExplicitlyConverted().(StaticCast).getActualType() instanceof VoidType
+// select fc, "Return value from call to $@ is unused.", f, f.getName()