INT34-C: Use fully converted type for precision

lcartey · lcartey · commit b79e1e84b6f0 · 2023-03-29T10:44:00.000+01:00
If the expression is explicitly converted to a larger type, the shift
happens on the larger type.
diff --git a/c/cert/src/rules/INT34-C/ExprShiftedbyNegativeOrGreaterPrecisionOperand.ql b/c/cert/src/rules/INT34-C/ExprShiftedbyNegativeOrGreaterPrecisionOperand.ql
@@ -55,7 +55,7 @@ int getPrecision(IntegralType type) {
 predicate isForbiddenShiftExpr(BitShiftExpr shift, string message) {
   (
     (
-      getPrecision(shift.getLeftOperand().getUnderlyingType()) <=
+      getPrecision(shift.getLeftOperand().getFullyConverted().getUnderlyingType()) <=
         upperBound(shift.getRightOperand()) and
       message =
         "The operand " + shift.getLeftOperand() + " is shifted by an expression " +

Original file line number	Diff line number	Diff line change
`@@ -55,7 +55,7 @@ int getPrecision(IntegralType type) {`
`55`	`55`	`predicate isForbiddenShiftExpr(BitShiftExpr shift, string message) {`
`56`	`56`	`(`
`57`	`57`	`(`
`58`		`- getPrecision(shift.getLeftOperand().getUnderlyingType()) <=`
	`58`	`+ getPrecision(shift.getLeftOperand().getFullyConverted().getUnderlyingType()) <=`
`59`	`59`	`upperBound(shift.getRightOperand()) and`
`60`	`60`	`message =`
`61`	`61`	`"The operand " + shift.getLeftOperand() + " is shifted by an expression " +`