xref: /llvm-project/clang-tools-extra/test/clang-tidy/checkers/modernize/min-max-use-initializer-list.cpp (revision 605a9adb4340b347f480a95a6eef3c9045e8416f)

// RUN: %check_clang_tidy %s modernize-min-max-use-initializer-list %t

// CHECK-FIXES: #include <algorithm>
namespace utils {
template <typename T>
T max(T a, T b) {
  return (a < b) ? b : a;
}
} // namespace utils

namespace std {
template< class T >
struct initializer_list {
  const T *a, *b;
  initializer_list()=default;
  initializer_list(T*,int){}
  const T* begin() const {return nullptr;}
  const T* end() const {return nullptr;}
};

template<class ForwardIt>
ForwardIt min_element(ForwardIt first, ForwardIt last)
{
    if (first == last)
        return last;

    ForwardIt smallest = first;

    while (++first != last)
        if (*first < *smallest)
            smallest = first;

    return smallest;
}

template<class ForwardIt, class Compare>
ForwardIt min_element(ForwardIt first, ForwardIt last, Compare comp)
{
    if (first == last)
        return last;

    ForwardIt smallest = first;

    while (++first != last)
        if (comp(*first, *smallest))
            smallest = first;

    return smallest;
}

template<class ForwardIt>
ForwardIt max_element(ForwardIt first, ForwardIt last)
{
    if (first == last)
        return last;

    ForwardIt largest = first;

    while (++first != last)
        if (*largest < *first)
            largest = first;

    return largest;
}

template<class ForwardIt, class Compare>
ForwardIt max_element(ForwardIt first, ForwardIt last, Compare comp)
{
    if (first == last)
        return last;

    ForwardIt largest = first;

    while(++first != last)
        if (comp(*largest, *first))
            largest = first;

    return largest;
}

template< class T >
const T& max( const T& a, const T& b ) {
  return (a < b) ? b : a;
};

template< class T >
T max(std::initializer_list<T> ilist)
{
    return *std::max_element(ilist.begin(), ilist.end());
}

template< class T, class Compare >
const T& max( const T& a, const T& b, Compare comp ) {
  return (comp(a, b)) ? b : a;
};

template< class T, class Compare >
T max(std::initializer_list<T> ilist, Compare comp) {
    return *std::max_element(ilist.begin(), ilist.end(), comp);
};

template< class T >
const T& min( const T& a, const T& b ) {
  return (b < a) ? b : a;
};

template< class T >
T min(std::initializer_list<T> ilist)
{
    return *std::min_element(ilist.begin(), ilist.end());
}


template< class T, class Compare >
const T& min( const T& a, const T& b, Compare comp ) {
  return (comp(b, a)) ? b : a;
};

template< class T, class Compare >
T min(std::initializer_list<T> ilist, Compare comp) {
    return *std::min_element(ilist.begin(), ilist.end(), comp);
};

} // namespace std

using namespace std;

namespace {
bool fless_than(int a, int b) {
return a < b;
}

bool fgreater_than(int a, int b) {
return a > b;
}
auto less_than = [](int a, int b) { return a < b; };
auto greater_than = [](int a, int b) { return a > b; };

int max1 = std::max(1, std::max(2, 3));
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max1 = std::max({1, 2, 3});

int min1 = std::min(1, std::min(2, 3));
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int min1 = std::min({1, 2, 3});

int max2 = std::max(1, std::max(2, std::max(3, 4)));
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max2 = std::max({1, 2, 3, 4});

int max2b = std::max(std::max(std::max(1, 2), std::max(3, 4)), std::max(std::max(5, 6), std::max(7, 8)));
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max2b = std::max({1, 2, 3, 4, 5, 6, 7, 8});

int max2c = std::max(std::max(1, std::max(2, 3)), 4);
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max2c = std::max({1, 2, 3, 4});

int max2d = std::max(std::max({1, 2, 3}), 4);
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max2d = std::max({1, 2, 3, 4});


int max2e = std::max(1, max(2, max(3, 4)));
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max2e = std::max({1, 2, 3, 4});

int min2 = std::min(1, std::min(2, std::min(3, 4)));
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int min2 = std::min({1, 2, 3, 4});

int max3 = std::max(std::max(4, 5), std::min(2, std::min(3, 1)));
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-MESSAGES: :[[@LINE-2]]:37: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max3 = std::max({4, 5, std::min({2, 3, 1})});

int min3 = std::min(std::min(4, 5), std::max(2, std::max(3, 1)));
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-MESSAGES: :[[@LINE-2]]:37: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int min3 = std::min({4, 5, std::max({2, 3, 1})});

int max4 = std::max(1, std::max(2, 3, greater_than), less_than);
// CHECK-FIXES: int max4 = std::max(1, std::max(2, 3, greater_than), less_than);

int min4 = std::min(1, std::min(2, 3, greater_than), less_than);
// CHECK-FIXES: int min4 = std::min(1, std::min(2, 3, greater_than), less_than);

int max5 = std::max(1, std::max(2, 3), less_than);
// CHECK-FIXES: int max5 = std::max(1, std::max(2, 3), less_than);

int min5 = std::min(1, std::min(2, 3), less_than);
// CHECK-FIXES: int min5 = std::min(1, std::min(2, 3), less_than);

int max6 = std::max(1, std::max(2, 3, greater_than), greater_than);
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max6 = std::max({1, 2, 3 }, greater_than);

int min6 = std::min(1, std::min(2, 3, greater_than), greater_than);
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int min6 = std::min({1, 2, 3 }, greater_than);

int max7 = std::max(1, std::max(2, 3, fless_than), fgreater_than);
// CHECK-FIXES: int max7 = std::max(1, std::max(2, 3, fless_than), fgreater_than);

int min7 = std::min(1, std::min(2, 3, fless_than), fgreater_than);
// CHECK-FIXES: int min7 = std::min(1, std::min(2, 3, fless_than), fgreater_than);

int max8 = std::max(1, std::max(2, 3, fless_than), less_than);
// CHECK-FIXES: int max8 = std::max(1, std::max(2, 3, fless_than), less_than)

int min8 = std::min(1, std::min(2, 3, fless_than), less_than);
// CHECK-FIXES: int min8 = std::min(1, std::min(2, 3, fless_than), less_than);

int max9 = std::max(1, std::max(2, 3, fless_than), fless_than);
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max9 = std::max({1, 2, 3 }, fless_than);

int min9 = std::min(1, std::min(2, 3, fless_than), fless_than);
// CHECK-MESSAGES: :[[@LINE-1]]:12: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int min9 = std::min({1, 2, 3 }, fless_than);

int min10 = std::min(std::min(4, 5), std::max(2, utils::max(3, 1)));
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use nested 'std::min' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int min10 = std::min({4, 5, std::max(2, utils::max(3, 1))});

int max10 = std::max({std::max(1, 2), std::max({5, 6, 1}), 2, std::min({1, 2, 4})});
// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int max10 = std::max({1, 2, 5, 6, 1, 2, std::min({1, 2, 4})});

int typecastTest = std::max(std::max<int>(0U, 0.0f), 0);
// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int typecastTest = std::max({static_cast<int>(0U), static_cast<int>(0.0f), 0});

int typecastTest1 = std::max(std::max<long>(0U, 0.0f), 0L);
// CHECK-MESSAGES: :[[@LINE-1]]:21: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int typecastTest1 = std::max({static_cast<long>(0U), static_cast<long>(0.0f), 0L});

int typecastTest2 = std::max(std::max<int>(10U, 20.0f), 30);
// CHECK-MESSAGES: :[[@LINE-1]]:21: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int typecastTest2 = std::max({static_cast<int>(10U), static_cast<int>(20.0f), 30});

int typecastTest3 = std::max(std::max<int>(0U, std::max<int>(0.0f, 1.0f)), 0);
// CHECK-MESSAGES: :[[@LINE-1]]:21: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int typecastTest3 = std::max({static_cast<int>(0U), static_cast<int>(0.0f), static_cast<int>(1.0f), 0});

#define max3f(a, b, c) std::max(a, std::max(b, c))
// CHECK-FIXES: #define max3f(a, b, c) std::max(a, std::max(b, c))

#define value 4545
int macroVarMax = std::max(value, std::max(1, 2));
// CHECK-MESSAGES: :[[@LINE-1]]:19: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int macroVarMax = std::max({value, 1, 2});

#define value2 45U
int macroVarMax2 = std::max(1, std::max<int>(value2, 2.0f));
// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: int macroVarMax2 = std::max({1, static_cast<int>(value2), static_cast<int>(2.0f)});

// True-negative tests
int maxTN1 = std::max(1, 2);
// CHECK-FIXES: int maxTN1 = std::max(1, 2);

int maxTN2 = std::max({1, 2, 3});
// CHECK-FIXES: int maxTN2 = std::max({1, 2, 3});

int maxTN3 = std::max({1, 2, 3}, less_than);
// CHECK-FIXES: int maxTN3 = std::max({1, 2, 3}, less_than);

// non-trivial types
struct A {
  int a;
  A(int a) : a(a) {}
  bool operator<(const A &rhs) const { return a < rhs.a; }
};

A maxNT1 = std::max(A(1), A(2));
// CHECK-FIXES: A maxNT1 = std::max(A(1), A(2));

A maxNT2 = std::max(A(1), std::max(A(2), A(3)));
// CHECK-FIXES: A maxNT2 = std::max(A(1), std::max(A(2), A(3)));

A maxNT3 = std::max(A(1), std::max(A(2), A(3)), [](const A &lhs, const A &rhs) { return lhs.a < rhs.a; });
// CHECK-FIXES: A maxNT3 = std::max(A(1), std::max(A(2), A(3)), [](const A &lhs, const A &rhs) { return lhs.a < rhs.a; });

// Trivial type with size greater than 32
struct B {
  // 9*4 = 36 bytes > 32 bytes
  int a[9];

  bool operator<(const B& rhs) const {
    return a[0] < rhs.a[0];
  }
};

B maxTT1 = std::max(B(), B());
// CHECK-FIXES: B maxTT1 = std::max(B(), B());

B maxTT2 = std::max(B(), std::max(B(), B()));
// CHECK-FIXES: B maxTT2 = std::max(B(), std::max(B(), B()));

B maxTT3 = std::max(B(), std::max(B(), B()), [](const B &lhs, const B &rhs) { return lhs.a[0] < rhs.a[0]; });
// CHECK-FIXES: B maxTT3 = std::max(B(), std::max(B(), B()), [](const B &lhs, const B &rhs) { return lhs.a[0] < rhs.a[0]; });

struct GH91982 {
  int fun0Args();
  int fun1Arg(int a);
  int fun2Args(int a, int b);
  int fun3Args(int a, int b, int c);
  int fun4Args(int a, int b, int c, int d);

  int foo() {
    return std::max(
        fun0Args(),
        std::max(fun1Arg(0),
                 std::max(fun2Args(0, 1),
                          std::max(fun3Args(0, 1, 2), fun4Args(0, 1, 2, 3)))));
// CHECK-MESSAGES: :[[@LINE-5]]:12: warning: do not use nested 'std::max' calls, use an initializer list instead [modernize-min-max-use-initializer-list]
// CHECK-FIXES: return std::max(
// CHECK-FIXES-NEXT: {fun0Args(),
// CHECK-FIXES-NEXT: fun1Arg(0),
// CHECK-FIXES-NEXT: fun2Args(0, 1),
// CHECK-FIXES-NEXT: fun3Args(0, 1, 2), fun4Args(0, 1, 2, 3)});
  }
};

struct GH107594 {
    int foo(int a, int b, char c) {
        return std::max<int>({a, b, c});
    }
};

} // namespace