80 lines · cpp
1// RUN: %clang_cc1 -fblocks -fsyntax-only -Wunused-but-set-variable -verify %s2 3struct S {4 int i;5};6 7struct __attribute__((warn_unused)) SWarnUnused {8 int j;9 void operator +=(int);10 void operator ++();11};12 13int f0() {14 int y; // expected-warning{{variable 'y' set but not used}}15 y = 0;16 17 int z __attribute__((unused));18 z = 0;19 20 // In C++, don't warn for structs. (following gcc's behavior)21 struct S s;22 struct S t;23 s = t;24 25 // Unless it's marked with the warn_unused attribute.26 struct SWarnUnused swu; // expected-warning{{variable 'swu' set but not used}}27 struct SWarnUnused swu2;28 swu = swu2;29 30 int x;31 x = 0;32 return x + 5;33}34 35void f1(void) {36 (void)^() {37 int y; // expected-warning{{variable 'y' set but not used}}38 y = 0;39 40 int x;41 x = 0;42 return x;43 };44}45 46void f2() {47 // Don't warn for either of these cases.48 constexpr int x = 2;49 const int y = 1;50 char a[x];51 char b[y];52}53 54void f3(int n) {55 // Don't warn for overloaded compound assignment operators.56 SWarnUnused swu;57 swu += n;58}59 60template<typename T> void f4(T n) {61 // Don't warn for (potentially) overloaded compound assignment operators in62 // template code.63 SWarnUnused swu;64 swu += n;65}66 67template <typename T> void f5() {68 // Don't warn for overloaded pre/post operators in template code.69 SWarnUnused swu;70 ++swu;71}72 73void f6() {74 if (int x = 123) {} // expected-warning{{variable 'x' set but not used}}75 76 while (int x = 123) {} // expected-warning{{variable 'x' set but not used}}77 78 for (; int x = 123;) {} // expected-warning{{variable 'x' set but not used}}79}80