1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 | // RUN: %clang_analyze_cc1 -triple i386-apple-darwin10 -analyzer-checker=core,debug.ExprInspection -analyzer-config ipa=none -verify %s void clang_analyzer_eval(bool); class A { public: virtual void f(){}; }; class B : public A{ public: int m; }; class C : public A{}; class BB: public B{}; // A lot of the tests below have the if statement in them, which forces the // analyzer to explore both path - when the result is 0 and not. This makes // sure that we definitely know that the result is non-0 (as the result of // the cast). int testDynCastFromRadar() { B aa; A *a = &aa; const int* res = 0; B *b = dynamic_cast<B*>(a); static const int i = 5; if(b) { res = &i; } else { res = 0; } return *res; // no warning } int testBaseToBase1() { B b; B *pb = &b; B *pbb = dynamic_cast<B*>(pb); const int* res = 0; static const int i = 5; if (pbb) { res = &i; } else { res = 0; } return *res; // no warning } int testMultipleLevelsOfSubclassing1() { BB bb; B *pb = &bb; A *pa = pb; B *b = dynamic_cast<B*>(pa); const int* res = 0; static const int i = 5; if (b) { res = &i; } else { res = 0; } return *res; // no warning } int testMultipleLevelsOfSubclassing2() { BB bb; A *pbb = &bb; B *b = dynamic_cast<B*>(pbb); BB *s = dynamic_cast<BB*>(b); const int* res = 0; static const int i = 5; if (s) { res = &i; } else { res = 0; } return *res; // no warning } int testMultipleLevelsOfSubclassing3() { BB bb; A *pbb = &bb; B *b = dynamic_cast<B*>(pbb); return b->m; // no warning } int testLHS() { B aa; A *a = &aa; return (dynamic_cast<B*>(a))->m; } int testLHS2() { B aa; A *a = &aa; return (*dynamic_cast<B*>(a)).m; } int testDynCastUnknown2(class A *a) { B *b = dynamic_cast<B*>(a); return b->m; // no warning } int testDynCastUnknown(class A *a) { B *b = dynamic_cast<B*>(a); const int* res = 0; static const int i = 5; if (b) { res = &i; } else { res = 0; } return *res; // expected-warning {{Dereference of null pointer}} } int testDynCastFail2() { C c; A *pa = &c; B *b = dynamic_cast<B*>(pa); return b->m; // expected-warning {{dereference of a null pointer}} } int testLHSFail() { C c; A *a = &c; return (*dynamic_cast<B*>(a)).m; // expected-warning {{Dereference of null pointer}} } int testBaseToDerivedFail() { A a; B *b = dynamic_cast<B*>(&a); return b->m; // expected-warning {{dereference of a null pointer}} } int testConstZeroFail() { B *b = dynamic_cast<B*>((A *)0); return b->m; // expected-warning {{dereference of a null pointer}} } int testConstZeroFail2() { A *a = 0; B *b = dynamic_cast<B*>(a); return b->m; // expected-warning {{dereference of a null pointer}} } int testUpcast() { B b; A *a = dynamic_cast<A*>(&b); const int* res = 0; static const int i = 5; if (a) { res = &i; } else { res = 0; } return *res; // no warning } int testCastToVoidStar() { A a; void *b = dynamic_cast<void*>(&a); const int* res = 0; static const int i = 5; if (b) { res = &i; } else { res = 0; } return *res; // no warning } int testReferenceSuccessfulCast() { B rb; B &b = dynamic_cast<B&>(rb); int *x = 0; return *x; // expected-warning {{Dereference of null pointer}} } int testReferenceFailedCast() { A a; B &b = dynamic_cast<B&>(a); int *x = 0; return *x; // no warning (An exception is thrown by the cast.) } // Here we allow any outcome of the cast and this is good because there is a // situation where this will fail. So if the user has written the code in this // way, we assume they expect the cast to succeed. // Note, this might need special handling if we track types of symbolic casts // and use them for dynamic_cast handling. int testDynCastMostLikelyWillFail(C *c) { B *b = 0; b = dynamic_cast<B*>(c); const int* res = 0; static const int i = 5; if (b) { res = &i; } else { res = 0; } // Note: IPA is turned off for this test because the code below shows how the // dynamic_cast could succeed. return *res; // expected-warning{{Dereference of null pointer}} } class M : public B, public C {}; void callTestDynCastMostLikelyWillFail() { M m; testDynCastMostLikelyWillFail(&m); } void testDynCastToMiddleClass () { class BBB : public BB {}; BBB obj; A &ref = obj; // These didn't always correctly layer base regions. B *ptr = dynamic_cast<B*>(&ref); clang_analyzer_eval(ptr != 0); // expected-warning{{TRUE}} // This is actually statically resolved to be a DerivedToBase cast. ptr = dynamic_cast<B*>(&obj); clang_analyzer_eval(ptr != 0); // expected-warning{{TRUE}} } // ----------------------------- // False positives/negatives. // ----------------------------- // Due to symbolic regions not being typed. int testDynCastFalsePositive(BB *c) { B *b = 0; b = dynamic_cast<B*>(c); const int* res = 0; static const int i = 5; if (b) { res = &i; } else { res = 0; } return *res; // expected-warning{{Dereference of null pointer}} } // Does not work when we new an object. int testDynCastFail3() { A *a = new A(); B *b = dynamic_cast<B*>(a); return b->m; } |