clang/test/SemaCXX/warn-max-unsigned-zero.cpp

   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