| title | Warning C26453 | ||
|---|---|---|---|
| description | Describes the causes of MSVC code analysis warning C26453, and shows how to fix it. | ||
| ms.date | 05/11/2023 | ||
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Arithmetic overflow: Left shift of a negative signed number is undefined behavior (io.4)
This warning indicates the code left shifts a negative signed integral value, which is nonportable and triggers implementation defined behavior.
Code analysis name: LEFTSHIFT_NEGATIVE_SIGNED_NUMBER
void leftshift(int shiftCount)
{
const auto result = -1 << shiftCount; // C26453 reported here
// code
}To correct this warning, use the following code:
void leftshift(int shiftCount)
{
const auto result = ~0u << shiftCount; // OK
// code
}26450
26451
26452
26454
ES.101: Use unsigned types for bit manipulation
ES.102: Use signed types for arithmetic