1 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-checker=deadcode.DeadStores -verify -Wno-unreachable-code %s 2 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-store=basic -analyzer-constraints=basic -analyzer-checker=deadcode.DeadStores -verify -Wno-unreachable-code %s 3 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-store=basic -analyzer-constraints=range -analyzer-checker=deadcode.DeadStores -verify -Wno-unreachable-code %s 4 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-store=region -analyzer-constraints=basic -analyzer-checker=deadcode.DeadStores -verify -Wno-unreachable-code %s 5 // RUN: %clang_cc1 -fcxx-exceptions -fexceptions -analyze -analyzer-store=region -analyzer-constraints=range -analyzer-checker=deadcode.DeadStores -verify -Wno-unreachable-code %s 6 7 //===----------------------------------------------------------------------===// 8 // Basic dead store checking (but in C++ mode). 9 //===----------------------------------------------------------------------===// 10 11 int j; 12 void test1() { 13 int x = 4; 14 15 x = x + 1; // expected-warning{{never read}} 16 17 switch (j) { 18 case 1: 19 throw 1; 20 (void)x; 21 break; 22 } 23 } 24 25 //===----------------------------------------------------------------------===// 26 // Dead store checking involving constructors. 27 //===----------------------------------------------------------------------===// 28 29 class Test2 { 30 int &x; 31 public: 32 Test2(int &y) : x(y) {} 33 ~Test2() { ++x; } 34 }; 35 36 int test2(int x) { 37 { Test2 a(x); } // no-warning 38 return x; 39 } 40 41 //===----------------------------------------------------------------------===// 42 // Dead store checking involving CXXTemporaryExprs 43 //===----------------------------------------------------------------------===// 44 45 namespace TestTemp { 46 template<typename _Tp> 47 class pencil { 48 public: 49 ~pencil() throw() {} 50 }; 51 template<typename _Tp, typename _Number2> struct _Row_base { 52 _Row_base(const pencil<_Tp>& x) {} 53 }; 54 template<typename _Tp, typename _Number2 = TestTemp::pencil<_Tp> > 55 class row : protected _Row_base<_Tp, _Number2> { 56 typedef _Row_base<_Tp, _Number2> _Base; 57 typedef _Number2 pencil_type; 58 public: 59 explicit row(const pencil_type& __a = pencil_type()) : _Base(__a) {} 60 }; 61 } 62 63 void test2_b() { 64 TestTemp::row<const char*> x; // no-warning 65 } 66 67 //===----------------------------------------------------------------------===// 68 // Test references. 69 //===----------------------------------------------------------------------===// 70 71 void test3_a(int x) { 72 x = x + 1; // expected-warning{{never read}} 73 } 74 75 void test3_b(int &x) { 76 x = x + 1; // no-warninge 77 } 78 79 void test3_c(int x) { 80 int &y = x; 81 // Shows the limitation of dead stores tracking. The write is really 82 // dead since the value cannot escape the function. 83 ++y; // no-warning 84 } 85 86 void test3_d(int &x) { 87 int &y = x; 88 ++y; // no-warning 89 } 90 91 void test3_e(int &x) { 92 int &y = x; 93 } 94 95 //===----------------------------------------------------------------------===// 96 // Dead stores involving 'new' 97 //===----------------------------------------------------------------------===// 98 99 static void test_new(unsigned n) { 100 char **p = new char* [n]; // expected-warning{{never read}} 101 } 102 103 //===----------------------------------------------------------------------===// 104 // Dead stores in namespaces. 105 //===----------------------------------------------------------------------===// 106 107 namespace foo { 108 int test_4(int x) { 109 x = 2; // expected-warning{{Value stored to 'x' is never read}} 110 x = 2; 111 return x; 112 } 113 } 114 115
