Test large and negative constants, use BigInt

Author: lcartey

cpp/misra/src/rules/RULE-7-0-4/InappropriateBitwiseOrShiftOperands.ql

@@ -34,20 +34,23 @@ predicate isValidShiftConstantRange(Expr right, Type leftType) {
 }
 
 predicate isSignedConstantLeftShiftException(LShiftExpr shift) {
-  exists(Expr left, Expr right, NumericType leftType, int leftVal, int rightVal, int maxBit |
+  exists(
+    Expr left, Expr right, NumericType leftType, QlBuiltins::BigInt leftVal, int rightVal,
+    int maxBit
+  |
     left = shift.getLeftOperand() and
     right = shift.getRightOperand() and
     leftType = left.getType() and
     isConstantExpression(left) and
     isConstantExpression(right) and
     isSignedType(leftType) and
     isValidShiftConstantRange(right, leftType) and
-    leftVal = left.getValue().toInt() and
+    leftVal = left.getValue().toBigInt() and
     rightVal = right.getValue().toInt() and
-    leftVal >= 0 and
+    leftVal >= 0.toBigInt() and
     maxBit = leftType.getSize() * 8 - 1 and
     // Check that no set bit is shifted into or beyond the sign bit
-    leftVal * 2.pow(rightVal) < 2.pow(maxBit)
+    leftVal * 2.toBigInt().pow(rightVal) < 2.toBigInt().pow(maxBit)
   )
 }
 
@@ -111,7 +114,6 @@ where
     or
     // Shift operators - right operand must be unsigned or constant in valid range
     exists(BinaryShiftOperation shift, Expr right |
-      shift = x and
       shift = x and
       right = shift.getRightOperand() and
       not isUnsignedType(right.getExplicitlyConverted().getType()) and

cpp/misra/test/rules/RULE-7-0-4/InappropriateBitwiseOrShiftOperands.expected

@@ -15,11 +15,16 @@
 | test.cpp:85:3:85:11 | ... << ... | Shift operator '<<' requires unsigned right operand or constant in valid range. |
 | test.cpp:86:3:86:11 | ... << ... | Shift operator '<<' requires unsigned right operand or constant in valid range. |
 | test.cpp:87:3:87:11 | ... >> ... | Shift operator '>>' requires unsigned right operand or constant in valid range. |
-| test.cpp:97:3:97:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:98:3:98:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:99:3:99:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:100:3:100:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:104:3:104:11 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:106:3:106:17 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:112:3:112:10 | ... << ... | Shift operator '<<' requires unsigned left operand. |
-| test.cpp:120:3:120:11 | ... >> ... | Shift operator '>>' requires unsigned left operand. |
+| test.cpp:93:3:93:11 | ... << ... | Shift operator '<<' requires unsigned right operand or constant in valid range. |
+| test.cpp:94:3:94:11 | ... << ... | Shift operator '<<' requires unsigned right operand or constant in valid range. |
+| test.cpp:95:3:95:11 | ... >> ... | Shift operator '>>' requires unsigned right operand or constant in valid range. |
+| test.cpp:96:3:96:11 | ... >> ... | Shift operator '>>' requires unsigned right operand or constant in valid range. |
+| test.cpp:106:3:106:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:107:3:107:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:108:3:108:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:109:3:109:9 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:113:3:113:11 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:117:3:117:30 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:119:3:119:17 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:125:3:125:10 | ... << ... | Shift operator '<<' requires unsigned left operand. |
+| test.cpp:133:3:133:11 | ... >> ... | Shift operator '>>' requires unsigned left operand. |

cpp/misra/test/rules/RULE-7-0-4/test.cpp

@@ -87,7 +87,16 @@ void test_shift_operators_right_operand_constant_range() {
   u32 >> 32; // NON_COMPLIANT
 }
 
-void test_exception_signed_constant_left_operand() {
+void test_shift_operators_negative_right_operand() {
+  std::uint32_t u32 = 0x12345678U;
+
+  u32 << -1; // NON_COMPLIANT
+  u32 << -5; // NON_COMPLIANT
+  u32 >> -1; // NON_COMPLIANT
+  u32 >> -3; // NON_COMPLIANT
+}
+
+void test_exception_signed_constant_left_operand_exception() {
   // Exception cases for signed constant expressions
   1 << 30; // COMPLIANT
   2 << 29; // COMPLIANT
@@ -99,9 +108,13 @@ void test_exception_signed_constant_left_operand() {
   4 << 29; // NON_COMPLIANT
   8 << 28; // NON_COMPLIANT
 
-  1LL << 31; // COMPLIANT - 64 bit type
-  1LL << 62; // COMPLIANT - 64 bit type
-  1LL << 63; // NON_COMPLIANT - 64 bit type
+  1LL << 31;                    // COMPLIANT - 64 bit type
+  1LL << 62;                    // COMPLIANT - 64 bit type
+  1LL << 63;                    // NON_COMPLIANT - 64 bit type
+  0x1000'0000'0000'0000LL << 2; // COMPLIANT
+  0x2000'0000'0000'0000LL << 1; // COMPLIANT
+
+  0x4000'0000'0000'0000LL << 1; // NON_COMPLIANT
 
   0x40000000 << 1; // NON_COMPLIANT
 }