Merge pull request #390 from github/lcartey/m5-0-20-pointers

Exclude pointer assign from bitwise assign

c/misra/src/rules/RULE-10-1/OperandsOfAnInappropriateEssentialType.ql

@@ -14,6 +14,7 @@
 import cpp
 import codingstandards.c.misra
 import codingstandards.c.misra.EssentialTypes
+import codingstandards.cpp.Bitwise
 
 /**
  * Holds if the operator `operator` has an operand `child` that is of an inappropriate essential type
@@ -177,7 +178,7 @@ predicate isInappropriateEssentialType(
     child =
       [
         operator.(BinaryBitwiseOperation).getAnOperand(),
-        operator.(AssignBitwiseOperation).getAnOperand()
+        operator.(Bitwise::AssignBitwiseOperation).getAnOperand()
       ] and
     not operator instanceof LShiftExpr and
     not operator instanceof RShiftExpr and

c/misra/test/rules/RULE-10-1/test.c

@@ -492,4 +492,6 @@ void pointerType() {
   b || b; // COMPLIANT
   p || b; // NON_COMPLIANT
   b || p; // NON_COMPLIANT
+  p += 1; // COMPLIANT
+  p -= 1; // COMPLIANT
 }

change_notes/2023-10-04-m5-0-20-exclude-pointer-bitwise.md

@@ -0,0 +1 @@
+ * `M5-0-20`, `M5-0-21`, `RULE-10-1` - exclude pointer assignment operators as bitwise operators.

change_notes/2023-11-07-use-misra-underlying-type.md

@@ -0,0 +1,2 @@
+- `M5-0-20` - `BitwiseOperatorOperandsHaveDifferentUnderlyingType.ql`:
+  - Use the Misra definition of underlying type.

cpp/autosar/src/rules/M5-0-20/BitwiseOperatorOperandsHaveDifferentUnderlyingType.ql

@@ -16,19 +16,30 @@
 
 import cpp
 import codingstandards.cpp.autosar
+import codingstandards.cpp.Bitwise
+import codingstandards.cpp.Conversion
 
 predicate isBinaryBitwiseOperation(Operation o, VariableAccess l, VariableAccess r) {
   exists(BinaryBitwiseOperation bbo | bbo = o |
     l = bbo.getLeftOperand() and r = bbo.getRightOperand()
   )
   or
-  exists(AssignBitwiseOperation abo | abo = o | l = abo.getLValue() and r = abo.getRValue())
+  exists(Bitwise::AssignBitwiseOperation abo | abo = o |
+    l = abo.getLValue() and
+    r = abo.getRValue()
+  )
 }
 
-from Operation o, Variable left, Variable right
+from
+  Operation o, VariableAccess left, VariableAccess right, Type leftUnderlyingType,
+  Type rightUnderlyingType
 where
   not isExcluded(o, ExpressionsPackage::bitwiseOperatorOperandsHaveDifferentUnderlyingTypeQuery()) and
   not o.isFromUninstantiatedTemplate(_) and
-  isBinaryBitwiseOperation(o, left.getAnAccess(), right.getAnAccess()) and
-  left.getUnderlyingType() != right.getUnderlyingType()
-select o, "Operands of the '" + o.getOperator() + "' operation have different underlying types."
+  isBinaryBitwiseOperation(o, left, right) and
+  leftUnderlyingType = MisraConversion::getUnderlyingType(left) and
+  rightUnderlyingType = MisraConversion::getUnderlyingType(right) and
+  leftUnderlyingType != rightUnderlyingType
+select o,
+  "Operands of the '" + o.getOperator() + "' operation have different underlying types '" +
+    leftUnderlyingType.getName() + "' and '" + rightUnderlyingType.getName() + "'."

cpp/autosar/src/rules/M5-0-21/BitwiseOperatorAppliedToSignedTypes.ql

@@ -17,14 +17,15 @@
 
 import cpp
 import codingstandards.cpp.autosar
+import codingstandards.cpp.Bitwise
 
 from Operation o, VariableAccess va
 where
   not isExcluded(o, ExpressionsPackage::bitwiseOperatorAppliedToSignedTypesQuery()) and
   (
     o instanceof UnaryBitwiseOperation or
     o instanceof BinaryBitwiseOperation or
-    o instanceof AssignBitwiseOperation
+    o instanceof Bitwise::AssignBitwiseOperation
   ) and
   o.getAnOperand() = va and
   va.getTarget().getUnderlyingType().(IntegralType).isSigned()

cpp/autosar/src/rules/M5-8-1/RightBitShiftOperandIsNegativeOrTooWide.ql

@@ -17,6 +17,7 @@
 
 import cpp
 import codingstandards.cpp.autosar
+import codingstandards.cpp.Bitwise
 
 class ShiftOperation extends Operation {
   Expr leftOperand;
@@ -33,7 +34,7 @@ class ShiftOperation extends Operation {
       rightOperand = o.getRightOperand()
     )
     or
-    exists(AssignBitwiseOperation o | this = o |
+    exists(Bitwise::AssignBitwiseOperation o | this = o |
       (
         o instanceof AssignLShiftExpr
         or

cpp/autosar/test/rules/M5-0-20/BitwiseOperatorOperandsHaveDifferentUnderlyingType.expected

@@ -1,21 +1,21 @@
-| test.cpp:18:3:18:6 | ... & ... | Operands of the '&' operation have different underlying types. |
-| test.cpp:19:3:19:7 | ... \| ... | Operands of the '\|' operation have different underlying types. |
-| test.cpp:20:3:20:7 | ... ^ ... | Operands of the '^' operation have different underlying types. |
-| test.cpp:21:3:21:8 | ... << ... | Operands of the '<<' operation have different underlying types. |
-| test.cpp:22:3:22:8 | ... >> ... | Operands of the '>>' operation have different underlying types. |
-| test.cpp:23:3:23:8 | ... &= ... | Operands of the '&=' operation have different underlying types. |
-| test.cpp:24:3:24:8 | ... \|= ... | Operands of the '\|=' operation have different underlying types. |
-| test.cpp:25:3:25:8 | ... ^= ... | Operands of the '^=' operation have different underlying types. |
-| test.cpp:26:3:26:9 | ... <<= ... | Operands of the '<<=' operation have different underlying types. |
-| test.cpp:27:3:27:9 | ... >>= ... | Operands of the '>>=' operation have different underlying types. |
-| test.cpp:45:3:45:6 | ... & ... | Operands of the '&' operation have different underlying types. |
-| test.cpp:46:3:46:7 | ... \| ... | Operands of the '\|' operation have different underlying types. |
-| test.cpp:47:3:47:7 | ... ^ ... | Operands of the '^' operation have different underlying types. |
-| test.cpp:48:3:48:8 | ... << ... | Operands of the '<<' operation have different underlying types. |
-| test.cpp:49:3:49:8 | ... >> ... | Operands of the '>>' operation have different underlying types. |
-| test.cpp:50:3:50:8 | ... &= ... | Operands of the '&=' operation have different underlying types. |
-| test.cpp:51:3:51:8 | ... \|= ... | Operands of the '\|=' operation have different underlying types. |
-| test.cpp:52:3:52:8 | ... ^= ... | Operands of the '^=' operation have different underlying types. |
-| test.cpp:53:3:53:9 | ... <<= ... | Operands of the '<<=' operation have different underlying types. |
-| test.cpp:54:3:54:9 | ... >>= ... | Operands of the '>>=' operation have different underlying types. |
-| test.cpp:67:3:67:14 | ... << ... | Operands of the '<<' operation have different underlying types. |
+| test.cpp:18:3:18:6 | ... & ... | Operands of the '&' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:19:3:19:7 | ... \| ... | Operands of the '\|' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:20:3:20:7 | ... ^ ... | Operands of the '^' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:21:3:21:8 | ... << ... | Operands of the '<<' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:22:3:22:8 | ... >> ... | Operands of the '>>' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:23:3:23:8 | ... &= ... | Operands of the '&=' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:24:3:24:8 | ... \|= ... | Operands of the '\|=' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:25:3:25:8 | ... ^= ... | Operands of the '^=' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:26:3:26:9 | ... <<= ... | Operands of the '<<=' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:27:3:27:9 | ... >>= ... | Operands of the '>>=' operation have different underlying types 'unsigned int' and 'unsigned short'. |
+| test.cpp:45:3:45:6 | ... & ... | Operands of the '&' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:46:3:46:7 | ... \| ... | Operands of the '\|' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:47:3:47:7 | ... ^ ... | Operands of the '^' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:48:3:48:8 | ... << ... | Operands of the '<<' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:49:3:49:8 | ... >> ... | Operands of the '>>' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:50:3:50:8 | ... &= ... | Operands of the '&=' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:51:3:51:8 | ... \|= ... | Operands of the '\|=' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:52:3:52:8 | ... ^= ... | Operands of the '^=' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:53:3:53:9 | ... <<= ... | Operands of the '<<=' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:54:3:54:9 | ... >>= ... | Operands of the '>>=' operation have different underlying types 'unsigned char' and 'unsigned short'. |
+| test.cpp:67:3:67:14 | ... << ... | Operands of the '<<' operation have different underlying types 'int &' and 'char &'. |

cpp/autosar/test/rules/M5-0-20/test.cpp

@@ -71,3 +71,8 @@ void test463_2_instantiations() {
   char shift2 = 2;
   test463_2(val, shift2);
 }
+
+void test_add(char *val) {
+  int add = 2;
+  val += add; // COMPLIANT
+}

cpp/autosar/test/rules/M5-0-21/test.cpp

@@ -45,4 +45,8 @@ void test() {
   u ^= u;  // COMPLIANT
   u | 0;   // COMPLIANT
   u |= 0;  // COMPLIANT
+
+  int *p = 0;
+  p += 1; // COMPLIANT
+  p -= 1; // COMPLIANT
 }

cpp/common/src/codingstandards/cpp/Bitwise.qll

@@ -0,0 +1,20 @@
+/**
+ * A library for addressing issues in bitwise operator modelling in our database schema.
+ */
+
+private import cpp as cpp
+
+module Bitwise {
+  /**
+   * A binary bitwise assign operation, excluding += and -= on pointers, which seem to be erroneously
+   * included.
+   */
+  class AssignBitwiseOperation extends cpp::AssignBitwiseOperation {
+    AssignBitwiseOperation() {
+      // exclude += and -= on pointers, which seem to be erroneously included
+      // in the database schema
+      not this instanceof cpp::AssignPointerAddExpr and
+      not this instanceof cpp::AssignPointerSubExpr
+    }
+  }
+}