31 lines
1.2 KiB
Plaintext
31 lines
1.2 KiB
Plaintext
The ``++sizeof++`` operator returns the size, in bytes, of its operand, which can be an expression or a type.
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Function parameters with array types automatically decay to pointers, so it is hazardous to call the ``++sizeof++`` operator on such variables.
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Moreover, calling the ``++sizeof++`` operator on a variable with pointer type is typically a mistake. Usually the intent was to get the size of the pointed-to value instead.
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== Noncompliant Code Example
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----
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void clear1(int array[]) {
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for (size_t i = 0; i < sizeof(array) / sizeof(*array); i+=1) { // Noncompliant, type of array decays to int *, so sizeof(array) evaluates to sizeof(int *)
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array[i] = 0;
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}
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}
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void clear2(short *array, int count) {
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memset(array, sizeof(array) * count); // Noncompliant, sizeof(array) evaluates to the size of a pointer to short and not of a short
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}
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----
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== See
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* https://www.securecoding.cert.org/confluence/x/6wE[CERT, ARR01-C] - Do not apply the sizeof operator to a pointer when taking the size of an array
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* https://www.securecoding.cert.org/confluence/x/9YAyAQ[CERT, CTR01-CPP] - Do not apply the sizeof operator to a pointer when taking the size of an array
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* http://cwe.mitre.org/data/definitions/467[MITRE, CWE-467] - Use of sizeof() on a Pointer Type
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