Ignore explicit casts when idenitying cvalues by parent

Author: lcartey

cpp/autosar/test/rules/M5-0-3/CvalueExpressionConvertedToDifferentUnderlyingType.expected

@@ -1,3 +1,5 @@
-| test.cpp:11:8:11:14 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:11:8:11:14 | ... + ... | expression |
-| test.cpp:11:8:11:14 | ... + ... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:11:8:11:14 | ... + ... | expression |
-| test.cpp:13:8:13:13 | ... + ... | Implicit conversion converts cvalue $@ from signed short to signed int. | test.cpp:13:8:13:13 | ... + ... | expression |
+| test.cpp:12:8:12:14 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:12:8:12:14 | ... + ... | expression |
+| test.cpp:12:8:12:14 | ... + ... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:12:8:12:14 | ... + ... | expression |
+| test.cpp:14:8:14:13 | ... + ... | Implicit conversion converts cvalue $@ from signed short to signed int. | test.cpp:14:8:14:13 | ... + ... | expression |
+| test.cpp:23:13:23:19 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:23:13:23:19 | ... + ... | expression |
+| test.cpp:30:12:30:18 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:30:12:30:18 | ... + ... | expression |

cpp/autosar/test/rules/M5-0-3/test.cpp

@@ -1,4 +1,5 @@
 #include <cstdint>
+
 void f1() {
   using std::int16_t;
   using std::int32_t;
@@ -13,4 +14,21 @@ void f1() {
   l3 = l2 + 1;                        // NON_COMPLIANT
   l3 = static_cast<int32_t>(l2) + 1;  // COMPLIANT
   l3 = l2 + 0x01ffff;                 // COMPLIANT
+}
+
+void int16_arg(std::int16_t t);
+
+void test_func_call() {
+  std::int8_t l1;
+  int16_arg(l1 + l1);                            // NON_COMPLIANT
+  int16_arg(static_cast<std::int16_t>(l1 + l1)); // COMPLIANT
+}
+
+std::int16_t test_return(int test) {
+  std::int8_t l1;
+  if (test > 0) {
+    return l1 + l1; // NON_COMPLIANT
+  } else {
+    return static_cast<std::int16_t>(l1 + l1); // COMPLIANT
+  }
 }

cpp/autosar/test/rules/M5-0-7/test.cpp

@@ -18,4 +18,13 @@ void f1() {
   s16a = static_cast<int16_t>(f32a / f32b); // NON_COMPLIANT
   s16a = static_cast<int16_t>(f32a);        // COMPLIANT
   s16a = static_cast<int16_t>(f32a) / f32b; // COMPLIANT
+}
+
+void int_arg(std::int32_t i);
+
+std::int16_t test_args() {
+  float f32a;
+  float f32b;
+  int_arg(static_cast<std::int16_t>(f32a)); // COMPLIANT - f32a is not a cvalue
+  return static_cast<std::int16_t>(f32a);   // COMPLIANT - f32a is not a cvalue
 }

cpp/autosar/test/rules/M5-0-8/test.cpp

@@ -22,4 +22,22 @@ void f() {
   f64 = static_cast<double>(1.0f + 1.0f); // NON_COMPLIANT
   f32 = static_cast<float>(1.0f + 1);     // COMPLIANT
   f64 = static_cast<double>(1.0 + 1); // COMPLIANT; no suffix defines a double
+}
+
+#include <vector>
+
+void function_args() {
+  std::vector<std::uint8_t> v{0};
+
+  std::uint32_t u32{0};
+  v.at(static_cast<std::size_t>(u32)); // COMPLIANT - cast is not a cvalue
+  std::size_t st =
+      static_cast<std::size_t>(u32); // COMPLIANT - cast is not a cvalue
+  v.at(st);
+}
+
+std::size_t return_args() {
+  std::uint32_t u32{0};
+
+  return static_cast<std::size_t>(u32); // COMPLIANT
 }

cpp/autosar/test/rules/M5-0-9/ExplicitSignednessConversionOfCValue.expected

@@ -1,3 +1,3 @@
-| test.cpp:16:8:16:35 | static_cast<int8_t>... | Explicit integral conversion converts the signedness of the $@ from unsigned to signed. | test.cpp:16:28:16:34 | ... + ... | cvalue |
-| test.cpp:18:8:18:40 | static_cast<int8_t>... | Explicit integral conversion converts the signedness of the $@ from unsigned to signed. | test.cpp:18:28:18:39 | ... + ... | cvalue |
-| test.cpp:20:8:20:35 | static_cast<int8_t>... | Explicit integral conversion converts the signedness of the $@ from unsigned to signed. | test.cpp:20:28:20:34 | ... * ... | cvalue |
+| test.cpp:20:8:20:35 | static_cast<int8_t>... | Explicit integral conversion converts the signedness of the $@ from unsigned to signed. | test.cpp:20:28:20:34 | ... + ... | cvalue |
+| test.cpp:22:8:22:40 | static_cast<int8_t>... | Explicit integral conversion converts the signedness of the $@ from unsigned to signed. | test.cpp:22:28:22:39 | ... + ... | cvalue |
+| test.cpp:24:8:24:35 | static_cast<int8_t>... | Explicit integral conversion converts the signedness of the $@ from unsigned to signed. | test.cpp:24:28:24:34 | ... * ... | cvalue |

cpp/autosar/test/rules/M5-0-9/test.cpp

@@ -1,4 +1,8 @@
 #include <cstdint>
+
+void signed_arg(std::uint32_t s);
+void unsigned_arg(std::uint32_t u);
+
 void f() {
   using std::int16_t;
   using std::int32_t;
@@ -22,4 +26,7 @@ void f() {
   i16 = static_cast<int16_t>(i16 / i8); // NON_COMPLIANT
 
   i8 = static_cast<int8_t>(u8) + static_cast<int8_t>(u8); // COMPLIANT
+
+  unsigned(static_cast<uint32_t>(i32)); // COMPLIANT - i32 is not a cvalue
+  signed(static_cast<int32_t>(u32));    // COMPLIANT - u32 is not a cvalue
 }

cpp/common/src/codingstandards/cpp/Expr.qll

@@ -148,9 +148,17 @@ module MisraExpr {
   private predicate isCValue(Expr e) {
     not e.isConstant() and
     (
-      exists(ReturnStmt return | e = return.getExpr())
+      exists(ReturnStmt return |
+        e = return.getExpr() and
+        // Only return statements which are not explicitly casted are considered
+        not exists(Cast c | not c.isImplicit() and c.getExpr() = e)
+      )
       or
-      exists(Call call | e = call.getAnArgument())
+      exists(FunctionCall call |
+        e = call.getAnArgument() and
+        // // Only function arguments which are not explicitly casted are considered
+        not exists(Cast c | not c.isImplicit() and c.getExpr() = e)
+      )
     )
     or
     isCValue(e.(ParenthesisExpr).getExpr())