// RUN: %check_clang_tidy %s bugprone-sizeof-expression %t -- -config="{CheckOptions: {bugprone-sizeof-expression.WarnOnSizeOfIntegerExpression: true}}" --
class C {
int size() { return sizeof(this); }
// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: suspicious usage of 'sizeof(this)'
};
#define LEN 8
int X;
extern int A[10];
extern short B[10];
#pragma pack(1)
struct S { char a, b, c; };
enum E { E_VALUE = 0 };
enum class EC { VALUE = 0 };
bool AsBool() { return false; }
int AsInt() { return 0; }
E AsEnum() { return E_VALUE; }
EC AsEnumClass() { return EC::VALUE; }
S AsStruct() { return {}; }
struct M {
int AsInt() { return 0; }
E AsEnum() { return E_VALUE; }
S AsStruct() { return {}; }
};
int ReturnOverload(int) { return {}; }
S ReturnOverload(S) { return {}; }
template <class T>
T ReturnTemplate(T) { return {}; }
template <class T>
bool TestTrait1() {
return sizeof(ReturnOverload(T{})) == sizeof(A);
}
template <class T>
bool TestTrait2() {
return sizeof(ReturnTemplate(T{})) == sizeof(A);
}
template <class T>
bool TestTrait3() {
return sizeof(ReturnOverload(0)) == sizeof(T{});
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
}
template <class T>
bool TestTrait4() {
return sizeof(ReturnTemplate(0)) == sizeof(T{});
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
}
bool TestTemplates() {
bool b = true;
b &= TestTrait1<int>();
b &= TestTrait1<S>();
b &= TestTrait2<int>();
b &= TestTrait2<S>();
b &= TestTrait3<int>();
b &= TestTrait3<S>();
b &= TestTrait4<int>();
b &= TestTrait4<S>();
return b;
}
int Test1(const char* ptr) {
int sum = 0;
sum += sizeof(LEN);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(K)'
sum += sizeof(LEN + 1);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(K)'
sum += sizeof(sum, LEN);
// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: suspicious usage of 'sizeof(..., ...)'
sum += sizeof(AsBool());
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
sum += sizeof(AsInt());
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
sum += sizeof(AsEnum());
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
sum += sizeof(AsEnumClass());
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
sum += sizeof(M{}.AsInt());
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
sum += sizeof(M{}.AsEnum());
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of integer type
sum += sizeof(sizeof(X));
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(sizeof(...))'
sum += sizeof(LEN + sizeof(X));
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(sizeof(...))'
sum += sizeof(LEN + LEN + sizeof(X));
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(sizeof(...))'
sum += sizeof(LEN + (LEN + sizeof(X)));
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(sizeof(...))'
sum += sizeof(LEN + -sizeof(X));
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(sizeof(...))'
sum += sizeof(LEN + - + -sizeof(X));
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(sizeof(...))'
sum += sizeof(char) / sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have the same type
sum += sizeof(A) / sizeof(S);
// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; numerator is not a multiple of denominator
sum += sizeof(char) / sizeof(int);
// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; numerator is not a multiple of denominator
sum += sizeof(char) / sizeof(A);
// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; numerator is not a multiple of denominator
sum += sizeof(B[0]) / sizeof(A);
// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; numerator is not a multiple of denominator
sum += sizeof(ptr) / sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; size of pointer is divided by size of pointed type
sum += sizeof(ptr) / sizeof(ptr[0]);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; size of pointer is divided by size of pointed type
sum += sizeof(ptr) / sizeof(char*);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have pointer types
sum += sizeof(ptr) / sizeof(void*);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have pointer types
sum += sizeof(ptr) / sizeof(const void volatile*);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have pointer types
sum += sizeof(ptr) / sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; size of pointer is divided by size of pointed type
sum += sizeof(int) * sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious 'sizeof' by 'sizeof' multiplication
sum += sizeof(ptr) * sizeof(ptr[0]);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious 'sizeof' by 'sizeof' multiplication
sum += sizeof(int) * (2 * sizeof(char));
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious 'sizeof' by 'sizeof' multiplication
sum += (2 * sizeof(char)) * sizeof(int);
// CHECK-MESSAGES: :[[@LINE-1]]:29: warning: suspicious 'sizeof' by 'sizeof' multiplication
if (sizeof(A) < 0x100000) sum += 42;
// CHECK-MESSAGES: :[[@LINE-1]]:17: warning: suspicious comparison of 'sizeof(expr)' to a constant
if (sizeof(A) <= 0xFFFFFFFEU) sum += 42;
// CHECK-MESSAGES: :[[@LINE-1]]:17: warning: suspicious comparison of 'sizeof(expr)' to a constant
return sum;
}
typedef char MyChar;
typedef const MyChar MyConstChar;
int CE0 = sizeof sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: suspicious usage of 'sizeof(sizeof(...))'
int CE1 = sizeof +sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: suspicious usage of 'sizeof(sizeof(...))'
int CE2 = sizeof sizeof(const char*);
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: suspicious usage of 'sizeof(sizeof(...))'
int CE3 = sizeof sizeof(const volatile char* const*);
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: suspicious usage of 'sizeof(sizeof(...))'
int CE4 = sizeof sizeof(MyConstChar);
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: suspicious usage of 'sizeof(sizeof(...))'
int Test2(MyConstChar* A) {
int sum = 0;
sum += sizeof(MyConstChar) / sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:30: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have the same type
sum += sizeof(MyConstChar) / sizeof(MyChar);
// CHECK-MESSAGES: :[[@LINE-1]]:30: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have the same type
sum += sizeof(A[0]) / sizeof(char);
// CHECK-MESSAGES: :[[@LINE-1]]:23: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have the same type
return sum;
}
template <int T>
int Foo() { int A[T]; return sizeof(T); }
// CHECK-MESSAGES: :[[@LINE-1]]:30: warning: suspicious usage of 'sizeof(K)'
template <typename T>
int Bar() { T A[5]; return sizeof(A[0]) / sizeof(T); }
// CHECK-MESSAGES: :[[@LINE-1]]:41: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have the same type
int Test3() { return Foo<42>() + Bar<char>(); }
static const char* kABC = "abc";
static const wchar_t* kDEF = L"def";
int Test4(const char A[10]) {
int sum = 0;
sum += sizeof(kABC);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(char*)'
sum += sizeof(kDEF);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(char*)'
return sum;
}
int Test5() {
typedef int Array10[10];
typedef C ArrayC[10];
struct MyStruct {
Array10 arr;
Array10* ptr;
};
typedef const MyStruct TMyStruct;
typedef const MyStruct *PMyStruct;
typedef TMyStruct *PMyStruct2;
static TMyStruct kGlocalMyStruct = {};
static TMyStruct volatile * kGlocalMyStructPtr = &kGlocalMyStruct;
MyStruct S;
PMyStruct PS;
PMyStruct2 PS2;
Array10 A10;
C *PtrArray[10];
C *PC;
char *PChar;
int *PInt, **PPInt;
MyStruct **PPMyStruct;
int sum = 0;
sum += sizeof(&S.arr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(&kGlocalMyStruct.arr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(&kGlocalMyStructPtr->arr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(S.arr + 0);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(+ S.arr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof((int*)S.arr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(S.ptr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(kGlocalMyStruct.ptr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(kGlocalMyStructPtr->ptr);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(&kGlocalMyStruct);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(&S);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(MyStruct*);
sum += sizeof(PMyStruct);
sum += sizeof(PS);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(PS2);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(&A10);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(PtrArray) / sizeof(PtrArray[1]);
// CHECK-MESSAGES: :[[@LINE-1]]:29: warning: suspicious usage of 'sizeof()' on an expression of pointer type
sum += sizeof(A10) / sizeof(PtrArray[0]);
sum += sizeof(PC) / sizeof(PtrArray[0]);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof()' on an expression of pointer type
// CHECK-MESSAGES: :[[@LINE-2]]:21: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; both expressions have the same type
sum += sizeof(ArrayC) / sizeof(PtrArray[0]);
// CHECK-MESSAGES: :[[@LINE-1]]:25: warning: suspicious usage of 'sizeof(...)/sizeof(...)'; numerator is not a multiple of denominator
// These pointers do not point to aggregate types, so they are not reported in this mode:
sum += sizeof(PChar);
sum += sizeof(PInt);
sum += sizeof(PPInt);
sum += sizeof(PPMyStruct);
return sum;
}
int Test6() {
int sum = 0;
struct S A = AsStruct(), B = AsStruct();
struct S *P = &A, *Q = &B;
sum += sizeof(struct S) == P - Q;
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += 5 * sizeof(S) != P - Q;
// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += sizeof(S) < P - Q;
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += 5 * sizeof(S) <= P - Q;
// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += 5 * sizeof(*P) >= P - Q;
// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += Q - P > 3 * sizeof(*P);
// CHECK-MESSAGES: :[[@LINE-1]]:22: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += sizeof(S) + (P - Q);
// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += 5 * sizeof(S) - (P - Q);
// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += (P - Q) / sizeof(S);
// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
sum += (P - Q) / sizeof(*Q);
// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic
return sum;
}
static constexpr inline int BufferSize = 1024;
template <typename T>
T next(const T *&Read) {
T value = *Read;
Read += sizeof(T);
return value;
}
void Test7() {
int Buffer[BufferSize];
int *P = &Buffer[0];
const int *P2 = P;
int V1 = next(P2);
// CHECK-MESSAGES: :[[@LINE-10]]:8: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic; this scaled value will be scaled again by the '+=' operator
// CHECK-MESSAGES: :[[@LINE-11]]:8: note: '+=' in pointer arithmetic internally scales with 'sizeof(const int)' == {{[0-9]+}}
int V2 = next(P2);
(void)V1;
(void)V2;
int *Q = P;
while (Q < P + sizeof(Buffer)) {
// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: suspicious usage of 'sizeof(...)' in pointer arithmetic; this scaled value will be scaled again by the '+' operator
// CHECK-MESSAGES: :[[@LINE-2]]:16: note: '+' in pointer arithmetic internally scales with 'sizeof(int)' == {{[0-9]+}}
*Q++ = 0;
}
}
#ifdef __SIZEOF_INT128__
template <__int128_t N>
#else
template <long N> // Fallback for platforms which do not define `__int128_t`
#endif
bool Baz() { return sizeof(A) < N; }
// CHECK-MESSAGES: :[[@LINE-1]]:31: warning: suspicious comparison of 'sizeof(expr)' to a constant
bool Test8() { return Baz<-1>(); }
void some_generic_function(const void *arg, int argsize);
int *IntP, **IntPP;
C *ClassP, **ClassPP;
void GenericFunctionTest() {
// The `sizeof(pointer)` checks ignore situations where the pointer is
// produced by dereferencing a pointer-to-pointer, because this is unlikely
// to be an accident and can appear in legitimate code that tries to call
// a generic function which emulates dynamic typing within C.
some_generic_function(IntPP, sizeof(*IntPP));
some_generic_function(ClassPP, sizeof(*ClassPP));
// Using `...[0]` instead of the dereference operator is another common
// variant, which is also widespread in the idiomatic array-size calculation:
// `sizeof(array) / sizeof(array[0])`.
some_generic_function(IntPP, sizeof(IntPP[0]));
some_generic_function(ClassPP, sizeof(ClassPP[0]));
// FIXME: There is a third common pattern where the generic function is
// called with `&Variable` and `sizeof(Variable)`. Right now these are
// reported by the `sizeof(pointer)` checks, but this causes some false
// positives, so it would be good to create an exception for them.
// NOTE: `sizeof(IntP)` is only reported with `WarnOnSizeOfPointer=true`.
some_generic_function(&IntPP, sizeof(IntP));
some_generic_function(&ClassPP, sizeof(ClassP));
// CHECK-MESSAGES: :[[@LINE-1]]:35: warning: suspicious usage of 'sizeof()' on an expression of pointer type
}
int ValidExpressions() {
int A[] = {1, 2, 3, 4};
static const char str[] = "hello";
static const char* ptr[] { "aaa", "bbb", "ccc" };
typedef C *CA10[10];
C *PtrArray[10];
CA10 PtrArray1;
int sum = 0;
if (sizeof(A) < 10)
sum += sizeof(A);
sum += sizeof(int);
sum += sizeof(AsStruct());
sum += sizeof(M{}.AsStruct());
sum += sizeof(A[sizeof(A) / sizeof(int)]);
sum += sizeof(&A[sizeof(A) / sizeof(int)]);
sum += sizeof(sizeof(0)); // Special case: sizeof size_t.
sum += sizeof(void*);
sum += sizeof(void const *);
sum += sizeof(void const *) / 4;
sum += sizeof(str);
sum += sizeof(str) / sizeof(char);
sum += sizeof(str) / sizeof(str[0]);
sum += sizeof(ptr) / sizeof(ptr[0]);
sum += sizeof(ptr) / sizeof(*(ptr));
sum += sizeof(PtrArray) / sizeof(PtrArray[0]);
// Canonical type of PtrArray1 is same as PtrArray.
sum = sizeof(PtrArray) / sizeof(PtrArray1[0]);
// There is no warning for 'sizeof(T*)/sizeof(Q)' case.
sum += sizeof(PtrArray) / sizeof(A[0]);
return sum;
}
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