Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 1 | // RUN: %clang_cc1 %s -fcxx-exceptions -fexceptions -fsyntax-only -verify -fblocks -std=c++11 -Wunreachable-code-aggressive -Wno-unused-value -Wno-tautological-compare |
Mike Stump | 4c45aa1 | 2010-01-21 15:20:48 +0000 | [diff] [blame] | 2 | |
Anders Carlsson | 5d1d7ae | 2010-09-03 00:25:02 +0000 | [diff] [blame] | 3 | int &halt() __attribute__((noreturn)); |
Mike Stump | 55f988e | 2010-01-21 17:21:23 +0000 | [diff] [blame] | 4 | int &live(); |
Mike Stump | 4c45aa1 | 2010-01-21 15:20:48 +0000 | [diff] [blame] | 5 | int dead(); |
| 6 | int liveti() throw(int); |
| 7 | int (*livetip)() throw(int); |
| 8 | |
| 9 | int test1() { |
| 10 | try { |
| 11 | live(); |
| 12 | } catch (int i) { |
| 13 | live(); |
| 14 | } |
| 15 | return 1; |
| 16 | } |
| 17 | |
| 18 | void test2() { |
| 19 | try { |
| 20 | live(); |
| 21 | } catch (int i) { |
| 22 | live(); |
| 23 | } |
| 24 | try { |
| 25 | liveti(); |
| 26 | } catch (int i) { |
| 27 | live(); |
| 28 | } |
| 29 | try { |
| 30 | livetip(); |
| 31 | } catch (int i) { |
| 32 | live(); |
| 33 | } |
| 34 | throw 1; |
| 35 | dead(); // expected-warning {{will never be executed}} |
| 36 | } |
Mike Stump | 55f988e | 2010-01-21 17:21:23 +0000 | [diff] [blame] | 37 | |
| 38 | |
| 39 | void test3() { |
| 40 | halt() |
| 41 | --; // expected-warning {{will never be executed}} |
Ted Kremenek | 7dd3c73 | 2010-12-16 08:22:16 +0000 | [diff] [blame] | 42 | // FIXME: The unreachable part is just the '?', but really all of this |
| 43 | // code is unreachable and shouldn't be separately reported. |
| 44 | halt() // expected-warning {{will never be executed}} |
| 45 | ? |
Mike Stump | e5fba70 | 2010-01-21 19:44:04 +0000 | [diff] [blame] | 46 | dead() : dead(); |
Mike Stump | 2d6ceab | 2010-01-21 22:12:18 +0000 | [diff] [blame] | 47 | live(), |
Ted Kremenek | 0c8e5a0 | 2011-07-19 14:18:48 +0000 | [diff] [blame] | 48 | float |
| 49 | (halt()); // expected-warning {{will never be executed}} |
Mike Stump | 55f988e | 2010-01-21 17:21:23 +0000 | [diff] [blame] | 50 | } |
Mike Stump | b5c7755 | 2010-01-21 23:15:53 +0000 | [diff] [blame] | 51 | |
| 52 | void test4() { |
| 53 | struct S { |
| 54 | int mem; |
| 55 | } s; |
| 56 | S &foor(); |
Zhongxing Xu | 9107166 | 2010-02-24 02:19:28 +0000 | [diff] [blame] | 57 | halt(), foor()// expected-warning {{will never be executed}} |
| 58 | .mem; |
Mike Stump | b5c7755 | 2010-01-21 23:15:53 +0000 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | void test5() { |
| 62 | struct S { |
| 63 | int mem; |
| 64 | } s; |
Richard Smith | a41c97a | 2013-09-20 01:15:31 +0000 | [diff] [blame] | 65 | S &foonr() __attribute__((noreturn)); |
| 66 | foonr() |
Mike Stump | b5c7755 | 2010-01-21 23:15:53 +0000 | [diff] [blame] | 67 | .mem; // expected-warning {{will never be executed}} |
| 68 | } |
| 69 | |
| 70 | void test6() { |
| 71 | struct S { |
| 72 | ~S() { } |
| 73 | S(int i) { } |
| 74 | }; |
| 75 | live(), |
Ted Kremenek | 0c8e5a0 | 2011-07-19 14:18:48 +0000 | [diff] [blame] | 76 | S |
| 77 | (halt()); // expected-warning {{will never be executed}} |
Mike Stump | b5c7755 | 2010-01-21 23:15:53 +0000 | [diff] [blame] | 78 | } |
Ted Kremenek | 5dfee06 | 2011-11-30 21:22:09 +0000 | [diff] [blame] | 79 | |
| 80 | // Don't warn about unreachable code in template instantiations, as |
| 81 | // they may only be unreachable in that specific instantiation. |
| 82 | void isUnreachable(); |
| 83 | |
| 84 | template <typename T> void test_unreachable_templates() { |
| 85 | T::foo(); |
| 86 | isUnreachable(); // no-warning |
| 87 | } |
| 88 | |
| 89 | struct TestUnreachableA { |
| 90 | static void foo() __attribute__((noreturn)); |
| 91 | }; |
| 92 | struct TestUnreachableB { |
| 93 | static void foo(); |
| 94 | }; |
| 95 | |
| 96 | void test_unreachable_templates_harness() { |
| 97 | test_unreachable_templates<TestUnreachableA>(); |
| 98 | test_unreachable_templates<TestUnreachableB>(); |
| 99 | } |
| 100 | |
Ted Kremenek | 75df4ee | 2011-12-01 00:59:17 +0000 | [diff] [blame] | 101 | // Do warn about explict template specializations, as they represent |
| 102 | // actual concrete functions that somebody wrote. |
| 103 | |
| 104 | template <typename T> void funcToSpecialize() {} |
| 105 | template <> void funcToSpecialize<int>() { |
| 106 | halt(); |
| 107 | dead(); // expected-warning {{will never be executed}} |
| 108 | } |
David Blaikie | 25f4c19 | 2012-01-24 04:29:27 +0000 | [diff] [blame] | 109 | |
Stephen Hines | 651f13c | 2014-04-23 16:59:28 -0700 | [diff] [blame] | 110 | // Handle 'try' code dominating a dead return. |
| 111 | enum PR19040_test_return_t |
| 112 | { PR19040_TEST_FAILURE }; |
| 113 | namespace PR19040_libtest |
| 114 | { |
| 115 | class A { |
| 116 | public: |
| 117 | ~A (); |
| 118 | }; |
| 119 | } |
| 120 | PR19040_test_return_t PR19040_fn1 () |
| 121 | { |
| 122 | try |
| 123 | { |
| 124 | throw PR19040_libtest::A (); |
| 125 | } catch (...) |
| 126 | { |
| 127 | return PR19040_TEST_FAILURE; |
| 128 | } |
| 129 | return PR19040_TEST_FAILURE; // expected-warning {{will never be executed}} |
| 130 | } |
| 131 | |
| 132 | __attribute__((noreturn)) |
| 133 | void raze(); |
| 134 | |
| 135 | namespace std { |
| 136 | template<typename T> struct basic_string { |
| 137 | basic_string(const T* x) {} |
| 138 | ~basic_string() {}; |
| 139 | }; |
| 140 | typedef basic_string<char> string; |
| 141 | } |
| 142 | |
| 143 | std::string testStr() { |
| 144 | raze(); |
| 145 | return ""; // expected-warning {{'return' will never be executed}} |
| 146 | } |
| 147 | |
| 148 | std::string testStrWarn(const char *s) { |
| 149 | raze(); |
| 150 | return s; // expected-warning {{will never be executed}} |
| 151 | } |
| 152 | |
| 153 | bool testBool() { |
| 154 | raze(); |
| 155 | return true; // expected-warning {{'return' will never be executed}} |
| 156 | } |
| 157 | |
| 158 | static const bool ConditionVar = 1; |
| 159 | int test_global_as_conditionVariable() { |
| 160 | if (ConditionVar) |
| 161 | return 1; |
| 162 | return 0; // no-warning |
| 163 | } |
| 164 | |
| 165 | // Handle unreachable temporary destructors. |
| 166 | class A { |
| 167 | public: |
| 168 | A(); |
| 169 | ~A(); |
| 170 | }; |
| 171 | |
| 172 | __attribute__((noreturn)) |
| 173 | void raze(const A& x); |
| 174 | |
| 175 | void test_with_unreachable_tmp_dtors(int x) { |
| 176 | raze(x ? A() : A()); // no-warning |
| 177 | } |
| 178 | |
| 179 | // Test sizeof - sizeof in enum declaration. |
| 180 | enum { BrownCow = sizeof(long) - sizeof(char) }; |
| 181 | enum { CowBrown = 8 - 1 }; |
| 182 | |
| 183 | |
| 184 | int test_enum_sizeof_arithmetic() { |
| 185 | if (BrownCow) |
| 186 | return 1; |
| 187 | return 2; |
| 188 | } |
| 189 | |
| 190 | int test_enum_arithmetic() { |
| 191 | if (CowBrown) |
| 192 | return 1; |
| 193 | return 2; // expected-warning {{never be executed}} |
| 194 | } |
| 195 | |
| 196 | int test_arithmetic() { |
| 197 | if (8 -1) |
| 198 | return 1; |
| 199 | return 2; // expected-warning {{never be executed}} |
| 200 | } |
| 201 | |
| 202 | int test_treat_const_bool_local_as_config_value() { |
| 203 | const bool controlValue = false; |
| 204 | if (!controlValue) |
| 205 | return 1; |
| 206 | test_treat_const_bool_local_as_config_value(); // no-warning |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | int test_treat_non_const_bool_local_as_non_config_value() { |
| 211 | bool controlValue = false; |
| 212 | if (!controlValue) |
| 213 | return 1; |
| 214 | // There is no warning here because 'controlValue' isn't really |
| 215 | // a control value at all. The CFG will not treat this |
| 216 | // branch as unreachable. |
| 217 | test_treat_non_const_bool_local_as_non_config_value(); // no-warning |
| 218 | return 0; |
| 219 | } |
| 220 | |
| 221 | void test_do_while(int x) { |
| 222 | // Handle trivial expressions with |
| 223 | // implicit casts to bool. |
| 224 | do { |
| 225 | break; |
| 226 | } while (0); // no-warning |
| 227 | } |
| 228 | |
| 229 | class Frobozz { |
| 230 | public: |
| 231 | Frobozz(int x); |
| 232 | ~Frobozz(); |
| 233 | }; |
| 234 | |
| 235 | Frobozz test_return_object(int flag) { |
| 236 | return Frobozz(flag); |
| 237 | return Frobozz(42); // expected-warning {{'return' will never be executed}} |
| 238 | } |
| 239 | |
| 240 | Frobozz test_return_object_control_flow(int flag) { |
| 241 | return Frobozz(flag); |
| 242 | return Frobozz(flag ? 42 : 24); // expected-warning {{code will never be executed}} |
| 243 | } |
| 244 | |
| 245 | void somethingToCall(); |
| 246 | |
| 247 | static constexpr bool isConstExprConfigValue() { return true; } |
| 248 | |
| 249 | int test_const_expr_config_value() { |
| 250 | if (isConstExprConfigValue()) { |
| 251 | somethingToCall(); |
| 252 | return 0; |
| 253 | } |
| 254 | somethingToCall(); // no-warning |
| 255 | return 1; |
| 256 | } |
| 257 | int test_const_expr_config_value_2() { |
| 258 | if (!isConstExprConfigValue()) { |
| 259 | somethingToCall(); // no-warning |
| 260 | return 0; |
| 261 | } |
| 262 | somethingToCall(); |
| 263 | return 1; |
| 264 | } |
| 265 | |
| 266 | class Frodo { |
| 267 | public: |
| 268 | static const bool aHobbit = true; |
| 269 | }; |
| 270 | |
| 271 | void test_static_class_var() { |
| 272 | if (Frodo::aHobbit) |
| 273 | somethingToCall(); |
| 274 | else |
| 275 | somethingToCall(); // no-warning |
| 276 | } |
| 277 | |
| 278 | void test_static_class_var(Frodo &F) { |
| 279 | if (F.aHobbit) |
| 280 | somethingToCall(); |
| 281 | else |
| 282 | somethingToCall(); // no-warning |
| 283 | } |
| 284 | |
| 285 | void test_unreachable_for_null_increment() { |
| 286 | for (unsigned i = 0; i < 10 ; ) // no-warning |
| 287 | break; |
| 288 | } |
| 289 | |
| 290 | void test_unreachable_forrange_increment() { |
| 291 | int x[10] = { 0 }; |
| 292 | for (auto i : x) { // expected-warning {{loop will run at most once (loop increment never executed)}} |
| 293 | break; |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | void calledFun() {} |
| 298 | |
| 299 | // Test "silencing" with parentheses. |
| 300 | void test_with_paren_silencing(int x) { |
| 301 | if (false) calledFun(); // expected-warning {{will never be executed}} expected-note {{silence by adding parentheses to mark code as explicitly dead}} |
| 302 | if ((false)) calledFun(); // no-warning |
| 303 | |
| 304 | if (true) // expected-note {{silence by adding parentheses to mark code as explicitly dead}} |
| 305 | calledFun(); |
| 306 | else |
| 307 | calledFun(); // expected-warning {{will never be executed}} |
| 308 | |
| 309 | if ((true)) |
| 310 | calledFun(); |
| 311 | else |
| 312 | calledFun(); // no-warning |
| 313 | |
| 314 | if (!true) // expected-note {{silence by adding parentheses to mark code as explicitly dead}} |
| 315 | calledFun(); // expected-warning {{code will never be executed}} |
| 316 | else |
| 317 | calledFun(); |
| 318 | |
| 319 | if ((!true)) |
| 320 | calledFun(); // no-warning |
| 321 | else |
| 322 | calledFun(); |
| 323 | |
| 324 | if (!(true)) |
| 325 | calledFun(); // no-warning |
| 326 | else |
| 327 | calledFun(); |
| 328 | } |
| 329 | |
Stephen Hines | 6bcf27b | 2014-05-29 04:14:42 -0700 | [diff] [blame] | 330 | void test_with_paren_silencing_impcast(int x) { |
| 331 | if (0) calledFun(); // expected-warning {{will never be executed}} expected-note {{silence by adding parentheses to mark code as explicitly dead}} |
| 332 | if ((0)) calledFun(); // no-warning |
| 333 | |
| 334 | if (1) // expected-note {{silence by adding parentheses to mark code as explicitly dead}} |
| 335 | calledFun(); |
| 336 | else |
| 337 | calledFun(); // expected-warning {{will never be executed}} |
| 338 | |
| 339 | if ((1)) |
| 340 | calledFun(); |
| 341 | else |
| 342 | calledFun(); // no-warning |
| 343 | |
| 344 | if (!1) // expected-note {{silence by adding parentheses to mark code as explicitly dead}} |
| 345 | calledFun(); // expected-warning {{code will never be executed}} |
| 346 | else |
| 347 | calledFun(); |
| 348 | |
| 349 | if ((!1)) |
| 350 | calledFun(); // no-warning |
| 351 | else |
| 352 | calledFun(); |
| 353 | |
| 354 | if (!(1)) |
| 355 | calledFun(); // no-warning |
| 356 | else |
| 357 | calledFun(); |
| 358 | } |
| 359 | |
| 360 | void tautological_compare(bool x, int y) { |
| 361 | if (x > 10) // expected-note {{silence}} |
| 362 | calledFun(); // expected-warning {{will never be executed}} |
| 363 | if (10 < x) // expected-note {{silence}} |
| 364 | calledFun(); // expected-warning {{will never be executed}} |
| 365 | if (x == 10) // expected-note {{silence}} |
| 366 | calledFun(); // expected-warning {{will never be executed}} |
| 367 | |
| 368 | if (x < 10) // expected-note {{silence}} |
| 369 | calledFun(); |
| 370 | else |
| 371 | calledFun(); // expected-warning {{will never be executed}} |
| 372 | if (10 > x) // expected-note {{silence}} |
| 373 | calledFun(); |
| 374 | else |
| 375 | calledFun(); // expected-warning {{will never be executed}} |
| 376 | if (x != 10) // expected-note {{silence}} |
| 377 | calledFun(); |
| 378 | else |
| 379 | calledFun(); // expected-warning {{will never be executed}} |
| 380 | |
| 381 | if (y != 5 && y == 5) // expected-note {{silence}} |
| 382 | calledFun(); // expected-warning {{will never be executed}} |
| 383 | |
| 384 | if (y > 5 && y < 4) // expected-note {{silence}} |
| 385 | calledFun(); // expected-warning {{will never be executed}} |
| 386 | |
| 387 | if (y < 10 || y > 5) // expected-note {{silence}} |
| 388 | calledFun(); |
| 389 | else |
| 390 | calledFun(); // expected-warning {{will never be executed}} |
| 391 | |
| 392 | // TODO: Extend warning to the following code: |
| 393 | if (x < -1) |
| 394 | calledFun(); |
| 395 | if (x == -1) |
| 396 | calledFun(); |
| 397 | |
| 398 | if (x != -1) |
| 399 | calledFun(); |
| 400 | else |
| 401 | calledFun(); |
| 402 | if (-1 > x) |
| 403 | calledFun(); |
| 404 | else |
| 405 | calledFun(); |
| 406 | |
| 407 | if (y == -1 && y != -1) |
| 408 | calledFun(); |
| 409 | } |