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// RUN: %check_clang_tidy %s cppcoreguidelines-pro-bounds-constant-array-index %t
typedef __SIZE_TYPE__ size_t;
namespace std {
template<typename T, size_t N>
struct array {
T& operator[](size_t n);
T& at(size_t n);
};
}
namespace gsl {
template<class T, size_t N>
T& at( T(&a)[N], size_t index );
template<class T, size_t N>
T& at( std::array<T, N> &a, size_t index );
}
constexpr int const_index(int base) {
return base + 3;
}
template<class T, size_t N>
class DerivedArray : public std::array<T, N> {};
void f(std::array<int, 10> a, int pos) {
a [ pos / 2 /*comment*/] = 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use array subscript when the index is not an integer constant expression [cppcoreguidelines-pro-bounds-constant-array-index]
int j = a[pos - 1];
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: do not use array subscript when the index is not an integer constant expression
a.at(pos-1) = 2; // OK, at() instead of []
gsl::at(a, pos-1) = 2; // OK, gsl::at() instead of []
a[-1] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index -1 is negative [cppcoreguidelines-pro-bounds-constant-array-index]
a[10] = 4;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements) [cppcoreguidelines-pro-bounds-constant-array-index]
a[const_index(7)] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements)
a[0] = 3; // OK, constant index and inside bounds
a[1] = 3; // OK, constant index and inside bounds
a[9] = 3; // OK, constant index and inside bounds
a[const_index(6)] = 3; // OK, constant index and inside bounds
using MyArray = std::array<int, 10>;
MyArray m{};
m [ pos / 2 /*comment*/] = 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use array subscript when the index is not an integer constant expression [cppcoreguidelines-pro-bounds-constant-array-index]
int jj = m[pos - 1];
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use array subscript when the index is not an integer constant expression
m.at(pos-1) = 2; // OK, at() instead of []
gsl::at(m, pos-1) = 2; // OK, gsl::at() instead of []
m[-1] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index -1 is negative [cppcoreguidelines-pro-bounds-constant-array-index]
m[10] = 4;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements) [cppcoreguidelines-pro-bounds-constant-array-index]
m[const_index(7)] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements)
m[0] = 3; // OK, constant index and inside bounds
m[1] = 3; // OK, constant index and inside bounds
m[9] = 3; // OK, constant index and inside bounds
m[const_index(6)] = 3; // OK, constant index and inside bounds
}
template<class T, size_t N>
class PrivateDerivedArray : std::array<T, N> {
public:
T& operator[](size_t n){
return std::array<T, N>::operator[](static_cast<int>(n));
};
T& at(size_t n) {
return std::array<T, N>::at(static_cast<int>(n));
};
};
void f_derived(DerivedArray<int, 10> a, int pos) {
a [ pos / 2 /*comment*/] = 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use array subscript when the index is not an integer constant expression [cppcoreguidelines-pro-bounds-constant-array-index]
int j = a[pos - 1];
// CHECK-MESSAGES: :[[@LINE-1]]:11: warning: do not use array subscript when the index is not an integer constant expression
a.at(pos-1) = 2; // OK, at() instead of []
gsl::at(a, pos-1) = 2; // OK, gsl::at() instead of []
a[-1] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index -1 is negative [cppcoreguidelines-pro-bounds-constant-array-index]
a[10] = 4;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements) [cppcoreguidelines-pro-bounds-constant-array-index]
a[const_index(7)] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements)
a[0] = 3; // OK, constant index and inside bounds
a[1] = 3; // OK, constant index and inside bounds
a[9] = 3; // OK, constant index and inside bounds
a[const_index(6)] = 3; // OK, constant index and inside bounds
using MyArray = DerivedArray<int, 10>;
MyArray m{};
m [ pos / 2 /*comment*/] = 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use array subscript when the index is not an integer constant expression [cppcoreguidelines-pro-bounds-constant-array-index]
int jj = m[pos - 1];
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use array subscript when the index is not an integer constant expression
m.at(pos-1) = 2; // OK, at() instead of []
gsl::at(m, pos-1) = 2; // OK, gsl::at() instead of []
m[-1] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index -1 is negative [cppcoreguidelines-pro-bounds-constant-array-index]
m[10] = 4;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements) [cppcoreguidelines-pro-bounds-constant-array-index]
m[const_index(7)] = 3;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: std::array<> index 10 is past the end of the array (which contains 10 elements)
m[0] = 3; // OK, constant index and inside bounds
m[1] = 3; // OK, constant index and inside bounds
m[9] = 3; // OK, constant index and inside bounds
m[const_index(6)] = 3; // OK, constant index and inside bounds
using MyPrivateArray = PrivateDerivedArray<int, 10>;
MyPrivateArray pm{};
pm [ pos / 2 /*comment*/] = 1;
int jjj = pm[pos - 1];
pm.at(pos-1) = 2; // OK, at() instead of []
pm[-1] = 3;
pm[10] = 4;
pm[const_index(7)] = 3;
pm[0] = 3; // OK, constant index and inside bounds
pm[1] = 3; // OK, constant index and inside bounds
pm[9] = 3; // OK, constant index and inside bounds
pm[const_index(6)] = 3; // OK, constant index and inside bounds
}
void g() {
int a[10];
for (int i = 0; i < 10; ++i) {
a[i] = i;
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use array subscript when the index is not an integer constant expression
// CHECK-FIXES: gsl::at(a, i) = i;
gsl::at(a, i) = i; // OK, gsl::at() instead of []
}
a[-1] = 3; // flagged by clang-diagnostic-array-bounds
a[10] = 4; // flagged by clang-diagnostic-array-bounds
a[const_index(7)] = 3; // flagged by clang-diagnostic-array-bounds
a[0] = 3; // OK, constant index and inside bounds
a[1] = 3; // OK, constant index and inside bounds
a[9] = 3; // OK, constant index and inside bounds
a[const_index(6)] = 3; // OK, constant index and inside bounds
}
struct S {
int& operator[](int i);
};
void customOperator() {
S s;
int i = 0;
s[i] = 3; // OK, custom operator
}
namespace ArrayInitIndexExpr {
struct A {
// The compiler-generated copy constructor uses an ArraySubscriptExpr. Don't warn.
int x[3];
};
void implicitCopyMoveCtor() {
// Force the compiler to generate a copy constructor.
A a;
A a2(a);
// Force the compiler to generate a move constructor.
A a3 = (A&&) a;
}
void lambdaCapture() {
int arr[3];
// Capturing an array by value uses an ArraySubscriptExpr. Don't warn.
[arr](){};
}
#if __cplusplus >= 201703L
void structuredBindings() {
int arr[3];
// Creating structured bindings by value uses an ArraySubscriptExpr. Don't warn.
auto [a,b,c] = arr;
}
#endif
} // namespace ArrayInitIndexExpr
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