1 // RUN: %clang_cc1 -fsyntax-only -Wmax-unsigned-zero -verify %s -std=c++11
2 // RUN: %clang_cc1 -fsyntax-only -Wmax-unsigned-zero %s -std=c++11 -fdiagnostics-parseable-fixits 2>&1 | FileCheck %s
3 
4 namespace std {
5 template <typename T>
6 T max(const T &, const T &);
7 }
8 
9 void test(unsigned u) {
10   auto a = std::max(55u, 0u);
11   // expected-warning@-1{{taking the max of a value and unsigned zero is always equal to the other value}}
12   // expected-note@-2{{remove call to max function and unsigned zero argument}}
13   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:20}:""
14   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:24-[[@LINE-4]]:28}:""
15   auto b = std::max(u, 0u);
16   // expected-warning@-1{{taking the max of a value and unsigned zero is always equal to the other value}}
17   // expected-note@-2{{remove call to max function and unsigned zero argument}}
18   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:20}:""
19   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:22-[[@LINE-4]]:26}:""
20   auto c = std::max(0u, 55u);
21   // expected-warning@-1{{taking the max of unsigned zero and a value is always equal to the other value}}
22   // expected-note@-2{{remove call to max function and unsigned zero argument}}
23   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:20}:""
24   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:21-[[@LINE-4]]:24}:""
25   auto d = std::max(0u, u);
26   // expected-warning@-1{{taking the max of unsigned zero and a value is always equal to the other value}}
27   // expected-note@-2{{remove call to max function and unsigned zero argument}}
28   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:20}:""
29   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:21-[[@LINE-4]]:24}:""
30 }
31 
32 void negative_test(signed s) {
33   auto a = std::max(0, s);
34   auto b = std::max(s, 0);
35   auto c = std::max(22, 0);
36   auto d = std::max(0, 22);
37 }
38 
39 template <unsigned x>
40 unsigned template_test() {
41   return std::max(x, 0u);
42   // expected-warning@-1{{taking the max of a value and unsigned zero is always equal to the other value}}
43   // expected-note@-2{{remove call to max function and unsigned zero argument}}
44   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:10-[[@LINE-3]]:18}:""
45   // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:20-[[@LINE-4]]:24}:""
46 }
47 
48 int a = template_test<0>() + template_test<1>() + template_test<2>();
49 
50 #define comp(x,y) std::max(x, y)
51 
52 int b = comp(0, 1);
53 int c = comp(0u, 1u);
54 int d = comp(2u, 0u);
55 
56