xref: /llvm-project/clang/test/SemaCXX/builtins-overflow.cpp (revision 436e5cc0f16b3f8542e0269a635ced9a4a058741)
1 // RUN: %clang_cc1 -fsyntax-only -std=c++17 -verify %s
2 // expected-no-diagnostics
3 
4 #include <limits.h>
5 
6 int a() {
7   const int x = 3;
8   static int z;
9   constexpr int *y = &z;
10   return []() { return __builtin_sub_overflow((int)x, (int)x, (int *)y); }();
11 }
12 int a2() {
13   const int x = 3;
14   static int z;
15   constexpr int *y = &z;
16   return []() { return __builtin_sub_overflow(x, x, y); }();
17 }
18 
19 template<typename T>
20 struct Result {
21   bool B;
22   T Value;
23   constexpr bool operator==(const Result<T> &Other) {
24     return B == Other.B && Value == Other.Value;
25   }
26 };
27 
28 
29 template <typename RET, typename LHS, typename RHS>
30 constexpr Result<RET> add(LHS &&lhs, RHS &&rhs) {
31   RET sum{};
32   return {__builtin_add_overflow(lhs, rhs, &sum), sum};
33 }
34 
35 static_assert(add<short>(static_cast<char>(120), static_cast<char>(10)) == Result<short>{false, 130});
36 static_assert(add<char>(static_cast<short>(120), static_cast<short>(10)) == Result<char>{true, -126});
37 static_assert(add<unsigned int>(INT_MAX, INT_MAX) == Result<unsigned int>{false, static_cast<unsigned int>(INT_MAX) * 2u});
38 static_assert(add<int>(static_cast<unsigned int>(INT_MAX), 1u) == Result<int>{true, INT_MIN});
39 
40 static_assert(add<int>(17, 22) == Result<int>{false, 39});
41 static_assert(add<int>(INT_MAX - 22, 24) == Result<int>{true, INT_MIN + 1});
42 static_assert(add<int>(INT_MIN + 22, -23) == Result<int>{true, INT_MAX});
43 
44 template <typename RET, typename LHS, typename RHS>
45 constexpr Result<RET> sub(LHS &&lhs, RHS &&rhs) {
46   RET sum{};
47   return {__builtin_sub_overflow(lhs, rhs, &sum), sum};
48 }
49 
50 static_assert(sub<unsigned char>(static_cast<char>(0),static_cast<char>(1)) == Result<unsigned char>{true, UCHAR_MAX});
51 static_assert(sub<char>(static_cast<unsigned char>(0),static_cast<unsigned char>(1)) == Result<char>{false, -1});
52 static_assert(sub<unsigned short>(static_cast<short>(0),static_cast<short>(1)) == Result<unsigned short>{true, USHRT_MAX});
53 
54 static_assert(sub<int>(17,22) == Result<int>{false, -5});
55 static_assert(sub<int>(INT_MAX - 22, -23) == Result<int>{true, INT_MIN});
56 static_assert(sub<int>(INT_MIN + 22, 23) == Result<int>{true, INT_MAX});
57 
58 template <typename RET, typename LHS, typename RHS>
59 constexpr Result<RET> mul(LHS &&lhs, RHS &&rhs) {
60   RET sum{};
61   return {__builtin_mul_overflow(lhs, rhs, &sum), sum};
62 }
63 
64 static_assert(mul<int>(17,22) == Result<int>{false, 374});
65 static_assert(mul<int>(INT_MAX / 22, 23) == Result<int>{true, -2049870757});
66 static_assert(mul<int>(INT_MIN / 22, -23) == Result<int>{true, -2049870757});
67 
68 constexpr Result<int> sadd(int lhs, int rhs) {
69   int sum{};
70   return {__builtin_sadd_overflow(lhs, rhs, &sum), sum};
71 }
72 
73 static_assert(sadd(17,22) == Result<int>{false, 39});
74 static_assert(sadd(INT_MAX - 22, 23) == Result<int>{true, INT_MIN});
75 static_assert(sadd(INT_MIN + 22, -23) == Result<int>{true, INT_MAX});
76 
77 constexpr Result<int> ssub(int lhs, int rhs) {
78   int sum{};
79   return {__builtin_ssub_overflow(lhs, rhs, &sum), sum};
80 }
81 
82 static_assert(ssub(17,22) == Result<int>{false, -5});
83 static_assert(ssub(INT_MAX - 22, -23) == Result<int>{true, INT_MIN});
84 static_assert(ssub(INT_MIN + 22, 23) == Result<int>{true, INT_MAX});
85 
86 constexpr Result<int> smul(int lhs, int rhs) {
87   int sum{};
88   return {__builtin_smul_overflow(lhs, rhs, &sum), sum};
89 }
90 
91 static_assert(smul(17,22) == Result<int>{false, 374});
92 static_assert(smul(INT_MAX / 22, 23) == Result<int>{true, -2049870757});
93 static_assert(smul(INT_MIN / 22, -23) == Result<int>{true, -2049870757});
94