818 lines · cpp
1// RUN: %clang_cc1 -fsyntax-only -verify=cxx11 -std=c++11 -Wno-unused -Wno-uninitialized \2// RUN: -Wunsequenced -Wno-c++17-extensions -Wno-c++14-extensions %s3// RUN: %clang_cc1 -fsyntax-only -verify=cxx17 -std=c++17 -Wno-unused -Wno-uninitialized \4// RUN: -Wunsequenced -Wno-c++17-extensions -Wno-c++14-extensions %s5 6int f(int, int = 0);7int g1();8int g2(int);9 10struct A {11 int x, y;12};13struct S {14 S(int, int);15 int n;16};17 18void test() {19 int a;20 int xs[10];21 ++a = 0; // ok22 a + ++a; // cxx11-warning {{unsequenced modification and access to 'a'}}23 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}24 a = ++a; // ok25 a + a++; // cxx11-warning {{unsequenced modification and access to 'a'}}26 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}27 a = a++; // cxx11-warning {{multiple unsequenced modifications to 'a'}}28 ++ ++a; // ok29 (a++, a++); // ok30 ++a + ++a; // cxx11-warning {{multiple unsequenced modifications to 'a'}}31 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}32 a++ + a++; // cxx11-warning {{multiple unsequenced modifications to 'a'}}33 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}34 (a++, a) = 0; // ok, increment is sequenced before value computation of LHS35 a = xs[++a]; // ok36 a = xs[a++]; // cxx11-warning {{multiple unsequenced modifications to 'a'}}37 (a ? xs[0] : xs[1]) = ++a; // cxx11-warning {{unsequenced modification and access to 'a'}}38 a = (++a, ++a); // ok39 a = (a++, ++a); // ok40 a = (a++, a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}41 f(a, a); // ok42 f(a = 0, a); // cxx11-warning {{unsequenced modification and access to 'a'}}43 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}44 f(a, a += 0); // cxx11-warning {{unsequenced modification and access to 'a'}}45 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}46 f(a = 0, a = 0); // cxx11-warning {{multiple unsequenced modifications to 'a'}}47 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}48 a = f(++a); // ok49 a = f(a++); // ok50 a = f(++a, a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}51 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}52 53 // Compound assignment "A OP= B" is equivalent to "A = A OP B" except that A54 // is evaluated only once.55 (++a, a) = 1; // ok56 (++a, a) += 1; // ok57 a = ++a; // ok58 a += ++a; // cxx11-warning {{unsequenced modification and access to 'a'}}59 60 A agg1 = { a++, a++ }; // ok61 A agg2 = { a++ + a, a++ }; // cxx11-warning {{unsequenced modification and access to 'a'}}62 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}63 64 S str1(a++, a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}65 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}66 S str2 = { a++, a++ }; // ok67 S str3 = { a++ + a, a++ }; // cxx11-warning {{unsequenced modification and access to 'a'}}68 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}69 70 struct Z { A a; S s; } z = { { ++a, ++a }, { ++a, ++a } }; // ok71 a = S { ++a, a++ }.n; // ok72 A { ++a, a++ }.x; // ok73 a = A { ++a, a++ }.x; // cxx11-warning {{multiple unsequenced modifications to 'a'}}74 A { ++a, a++ }.x + A { ++a, a++ }.y; // cxx11-warning {{multiple unsequenced modifications to 'a'}}75 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}76 77 (xs[2] && (a = 0)) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}78 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}79 (0 && (a = 0)) + a; // ok80 (1 && (a = 0)) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}81 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}82 83 (xs[3] || (a = 0)) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}84 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}85 (0 || (a = 0)) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}86 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}87 (1 || (a = 0)) + a; // ok88 89 (xs[4] ? a : ++a) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}90 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}91 (0 ? a : ++a) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}92 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}93 (1 ? a : ++a) + a; // ok94 (0 ? a : a++) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}95 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}96 (1 ? a : a++) + a; // ok97 (xs[5] ? ++a : ++a) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}98 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}99 100 (++a, xs[6] ? ++a : 0) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}101 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}102 103 // Here, the read of the fourth 'a' might happen before or after the write to104 // the second 'a'.105 a += (a++, a) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}106 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}107 108 a = a++ && a; // ok109 110 A *q = &agg1;111 (q = &agg2)->y = q->x; // cxx11-warning {{unsequenced modification and access to 'q'}}112 113 // This has undefined behavior if a == 0; otherwise, the side-effect of the114 // increment is sequenced before the value computation of 'f(a, a)', which is115 // sequenced before the value computation of the '&&', which is sequenced116 // before the assignment. We treat the sequencing in '&&' as being117 // unconditional.118 a = a++ && f(a, a);119 120 // This has undefined behavior if a != 0.121 (a && a++) + a; // cxx11-warning {{unsequenced modification and access to 'a'}}122 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}123 124 // FIXME: Don't warn here.125 (xs[7] && ++a) * (!xs[7] && ++a); // cxx11-warning {{multiple unsequenced modifications to 'a'}}126 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}127 128 xs[0] = (a = 1, a); // ok129 (a -= 128) &= 128; // ok130 ++a += 1; // ok131 132 xs[8] ? ++a + a++ : 0; // cxx11-warning {{multiple unsequenced modifications to 'a'}}133 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}134 xs[8] ? 0 : ++a + a++; // cxx11-warning {{multiple unsequenced modifications to 'a'}}135 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}136 xs[8] ? ++a : a++; // no-warning137 xs[8] ? a+=1 : a+= 2; // no-warning138 (xs[8] ? a+=1 : a+= 2) = a; // cxx11-warning {{unsequenced modification and access to 'a'}}139 (xs[8] ? a+=1 : a) = a; // cxx11-warning {{unsequenced modification and access to 'a'}}140 (xs[8] ? a : a+= 2) = a; // cxx11-warning {{unsequenced modification and access to 'a'}}141 a = (xs[8] ? a+=1 : a+= 2); // no-warning142 a += (xs[8] ? a+=1 : a+= 2); // cxx11-warning {{unsequenced modification and access to 'a'}}143 144 (false ? a+=1 : a) = a; // no-warning145 (true ? a+=1 : a) = a; // cxx11-warning {{unsequenced modification and access to 'a'}}146 (false ? a : a+=2) = a; // cxx11-warning {{unsequenced modification and access to 'a'}}147 (true ? a : a+=2) = a; // no-warning148 149 xs[8] && (++a + a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}150 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}151 xs[8] || (++a + a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}152 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}153 154 ((a++, false) || (a++, false)); // no-warning PR39779155 ((a++, true) && (a++, true)); // no-warning PR39779156 157 int i,j;158 (i = g1(), false) || (j = g2(i)); // no-warning PR22197159 (i = g1(), true) && (j = g2(i)); // no-warning PR22197160 161 (a++, false) || (a++, false) || (a++, false) || (a++, false); // no-warning162 (a++, true) || (a++, true) || (a++, true) || (a++, true); // no-warning163 a = ((a++, false) || (a++, false) || (a++, false) || (a++, false)); // no-warning164 a = ((a++, true) && (a++, true) && (a++, true) && (a++, true)); // no-warning165 a = ((a++, false) || (a++, false) || (a++, false) || a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}166 a = ((a++, true) && (a++, true) && (a++, true) && a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}167 a = ((a++, false) || (a++, false) || (a++, false) || (a + a, false)); // no-warning168 a = ((a++, true) && (a++, true) && (a++, true) && (a + a, true)); // no-warning169 170 a = (false && a++); // no-warning171 a = (true && a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}172 a = (true && ++a); // no-warning173 a = (true || a++); // no-warning174 a = (false || a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}175 a = (false || ++a); // no-warning176 177 (a++) | (a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}178 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}179 (a++) & (a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}180 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}181 (a++) ^ (a++); // cxx11-warning {{multiple unsequenced modifications to 'a'}}182 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}183 184 (__builtin_classify_type(++a) ? 1 : 0) + ++a; // ok185 (__builtin_constant_p(++a) ? 1 : 0) + ++a; // ok186 (__builtin_object_size(&(++a, a), 0) ? 1 : 0) + ++a; // ok187 (__builtin_expect(++a, 0) ? 1 : 0) + ++a; // cxx11-warning {{multiple unsequenced modifications to 'a'}}188 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}189 190 191 int *p = xs;192 a = *(a++, p); // no-warning193 p[(long long unsigned)(p = 0)]; // cxx11-warning {{unsequenced modification and access to 'p'}}194 (i++, xs)[i++]; // cxx11-warning {{multiple unsequenced modifications to 'i'}}195 (++i, xs)[++i]; // cxx11-warning {{multiple unsequenced modifications to 'i'}}196 (i, xs)[++i + ++i]; // cxx11-warning {{multiple unsequenced modifications to 'i'}}197 // cxx17-warning@-1 {{multiple unsequenced modifications to 'i'}}198 p++[p == xs]; // cxx11-warning {{unsequenced modification and access to 'p'}}199 ++p[p++ == xs]; // cxx11-warning {{unsequenced modification and access to 'p'}}200 201 struct S { int x; } s, *ps = &s;202 int (S::*PtrMem);203 (PtrMem = &S::x ,s).*(PtrMem); // cxx11-warning {{unsequenced modification and access to 'PtrMem'}}204 (PtrMem = &S::x ,s).*(PtrMem = &S::x); // cxx11-warning {{multiple unsequenced modifications to 'PtrMem'}}205 (PtrMem = &S::x ,ps)->*(PtrMem); // cxx11-warning {{unsequenced modification and access to 'PtrMem'}}206 (PtrMem = &S::x ,ps)->*(PtrMem = &S::x); // cxx11-warning {{multiple unsequenced modifications to 'PtrMem'}}207 (PtrMem = nullptr) == (PtrMem = nullptr); // cxx11-warning {{multiple unsequenced modifications to 'PtrMem'}}208 // cxx17-warning@-1 {{multiple unsequenced modifications to 'PtrMem'}}209 (PtrMem = nullptr) == PtrMem; // cxx11-warning {{unsequenced modification and access to 'PtrMem'}}210 // cxx17-warning@-1 {{unsequenced modification and access to 'PtrMem'}}211 212 i++ << i++; // cxx11-warning {{multiple unsequenced modifications to 'i'}}213 ++i << ++i; // cxx11-warning {{multiple unsequenced modifications to 'i'}}214 i++ << i; // cxx11-warning {{unsequenced modification and access to 'i'}}215 i << i++; // cxx11-warning {{unsequenced modification and access to 'i'}}216 i++ >> i++; // cxx11-warning {{multiple unsequenced modifications to 'i'}}217 ++i >> ++i; // cxx11-warning {{multiple unsequenced modifications to 'i'}}218 i++ >> i; // cxx11-warning {{unsequenced modification and access to 'i'}}219 i >> i++; // cxx11-warning {{unsequenced modification and access to 'i'}}220 (i++ << i) + i; // cxx11-warning {{unsequenced modification and access to 'i'}}221 // cxx17-warning@-1 {{unsequenced modification and access to 'i'}}222 (i++ << i) << i++; // cxx11-warning {{unsequenced modification and access to 'i'}}223 224 ++i = i++; // cxx11-warning {{multiple unsequenced modifications to 'i'}}225 i = i+= 1; // no-warning226 i = i++ + ++i; // cxx11-warning {{multiple unsequenced modifications to 'i'}}227 // cxx17-warning@-1 {{multiple unsequenced modifications to 'i'}}228 ++i += ++i; // cxx11-warning {{multiple unsequenced modifications to 'i'}}229 ++i += i++; // cxx11-warning {{multiple unsequenced modifications to 'i'}}230 (i++, i) += ++i; // cxx11-warning {{multiple unsequenced modifications to 'i'}}231 (i++, i) += i++; // cxx11-warning {{multiple unsequenced modifications to 'i'}}232 i += i+= 1; // cxx11-warning {{unsequenced modification and access to 'i'}}233 i += i++; // cxx11-warning {{unsequenced modification and access to 'i'}}234 i += ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}235 i -= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}236 i -= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}237 i *= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}238 i *= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}239 i /= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}240 i /= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}241 i %= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}242 i %= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}243 i ^= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}244 i ^= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}245 i |= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}246 i |= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}247 i &= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}248 i &= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}249 i <<= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}250 i <<= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}251 i >>= i++; // cxx11-warning {{unsequenced modification and access to 'i'}}252 i >>= ++i; // cxx11-warning {{unsequenced modification and access to 'i'}}253 254 p[i++] = i; // cxx11-warning {{unsequenced modification and access to 'i'}}255 p[i++] = (i = 42); // cxx11-warning {{multiple unsequenced modifications to 'i'}}256 p++[i++] = (i = p ? i++ : i++); // cxx11-warning {{unsequenced modification and access to 'p'}}257 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}258 259 (i++, f)(i++, 42); // cxx11-warning {{multiple unsequenced modifications to 'i'}}260 (i++ + i++, f)(42, 42); // cxx11-warning {{multiple unsequenced modifications to 'i'}}261 // cxx17-warning@-1 {{multiple unsequenced modifications to 'i'}}262 int (*pf)(int, int);263 (pf = f)(pf != nullptr, pf != nullptr); // cxx11-warning {{unsequenced modification and access to 'pf'}}264 pf((pf = f) != nullptr, 42); // cxx11-warning {{unsequenced modification and access to 'pf'}}265 f((pf = f, 42), (pf = f, 42)); // cxx11-warning {{multiple unsequenced modifications to 'pf'}}266 // cxx17-warning@-1 {{multiple unsequenced modifications to 'pf'}}267 pf((pf = f) != nullptr, pf == nullptr); // cxx11-warning {{unsequenced modification and access to 'pf'}}268 // cxx17-warning@-1 {{unsequenced modification and access to 'pf'}}269}270 271namespace PR20819 {272 struct foo { void bar(int); };273 foo get_foo(int);274 275 void g() {276 int a = 0;277 get_foo(a).bar(a++); // cxx11-warning {{unsequenced modification and access to 'a'}}278 }279}280 281namespace overloaded_operators {282 struct E {283 E &operator=(E &);284 E operator()(E);285 E operator()(E, E);286 E operator[](E);287 } e;288 // Binary operators with unsequenced operands.289 E operator+(E,E);290 E operator-(E,E);291 E operator*(E,E);292 E operator/(E,E);293 E operator%(E,E);294 E operator^(E,E);295 E operator&(E,E);296 E operator|(E,E);297 298 E operator<(E,E);299 E operator>(E,E);300 E operator==(E,E);301 E operator!=(E,E);302 E operator>=(E,E);303 E operator<=(E,E);304 305 // Binary operators where the RHS is sequenced before the LHS in C++17.306 E operator+=(E,E);307 E operator-=(E,E);308 E operator*=(E,E);309 E operator/=(E,E);310 E operator%=(E,E);311 E operator^=(E,E);312 E operator&=(E,E);313 E operator|=(E,E);314 E operator<<=(E,E);315 E operator>>=(E,E);316 317 // Binary operators where the LHS is sequenced before the RHS in C++17.318 E operator<<(E,E);319 E operator>>(E,E);320 E operator&&(E,E);321 E operator||(E,E);322 E operator,(E,E);323 E operator->*(E,E);324 325 void test() {326 int i = 0;327 // Binary operators with unsequenced operands.328 ((void)i++,e) + ((void)i++,e);329 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}330 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}331 ((void)i++,e) - ((void)i++,e);332 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}333 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}334 ((void)i++,e) * ((void)i++,e);335 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}336 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}337 ((void)i++,e) / ((void)i++,e);338 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}339 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}340 ((void)i++,e) % ((void)i++,e);341 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}342 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}343 ((void)i++,e) ^ ((void)i++,e);344 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}345 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}346 ((void)i++,e) & ((void)i++,e);347 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}348 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}349 ((void)i++,e) | ((void)i++,e);350 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}351 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}352 353 ((void)i++,e) < ((void)i++,e);354 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}355 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}356 ((void)i++,e) > ((void)i++,e);357 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}358 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}359 ((void)i++,e) == ((void)i++,e);360 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}361 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}362 ((void)i++,e) != ((void)i++,e);363 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}364 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}365 ((void)i++,e) <= ((void)i++,e);366 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}367 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}368 ((void)i++,e) >= ((void)i++,e);369 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}370 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}371 372 // Binary operators where the RHS is sequenced before the LHS in C++17.373 ((void)i++,e) = ((void)i++,e);374 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}375 ((void)i++,e) += ((void)i++,e);376 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}377 ((void)i++,e) -= ((void)i++,e);378 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}379 ((void)i++,e) *= ((void)i++,e);380 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}381 ((void)i++,e) /= ((void)i++,e);382 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}383 ((void)i++,e) %= ((void)i++,e);384 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}385 ((void)i++,e) ^= ((void)i++,e);386 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}387 ((void)i++,e) &= ((void)i++,e);388 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}389 ((void)i++,e) |= ((void)i++,e);390 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}391 ((void)i++,e) <<= ((void)i++,e);392 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}393 ((void)i++,e) >>= ((void)i++,e);394 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}395 396 operator+=(((void)i++,e), ((void)i++,e));397 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}398 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}399 400 // Binary operators where the LHS is sequenced before the RHS in C++17.401 ((void)i++,e) << ((void)i++,e);402 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}403 ((void)i++,e) >> ((void)i++,e);404 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}405 ((void)i++,e) || ((void)i++,e);406 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}407 ((void)i++,e) && ((void)i++,e);408 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}409 ((void)i++,e) , ((void)i++,e);410 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}411 ((void)i++,e)->*((void)i++,e);412 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}413 414 operator<<(((void)i++,e), ((void)i++,e));415 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}416 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}417 418 ((void)i++,e)[((void)i++,e)];419 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}420 421 ((void)i++,e)(((void)i++,e));422 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}423 e(((void)i++,e), ((void)i++,e));424 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}425 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}426 427 ((void)i++,e).operator()(((void)i++,e));428 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}429 430 }431}432 433namespace PR35340 {434 struct S {};435 S &operator<<(S &, int);436 437 void test() {438 S s;439 int i = 0;440 s << i++ << i++;441 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}442 443 operator<<(operator<<(s, i++), i++);444 // cxx11-warning@-1 {{multiple unsequenced modifications to 'i'}}445 // cxx17-warning@-2 {{multiple unsequenced modifications to 'i'}}446 }447}448 449namespace members {450 451struct S1 {452 unsigned bf1 : 2;453 unsigned bf2 : 2;454 unsigned a;455 unsigned b;456 static unsigned x;457 void member_f(S1 &s);458};459 460void S1::member_f(S1 &s) {461 ++a + ++a; // cxx11-warning {{multiple unsequenced modifications to 'a'}}462 // cxx17-warning@-1 {{multiple unsequenced modifications to 'a'}}463 a + ++a; // cxx11-warning {{unsequenced modification and access to 'a'}}464 // cxx17-warning@-1 {{unsequenced modification and access to 'a'}}465 ++a + ++b; // no-warning466 a + ++b; // no-warning467 468 // TODO: Warn here.469 ++s.a + ++s.a; // no-warning TODO {{multiple unsequenced modifications to}}470 s.a + ++s.a; // no-warning TODO {{unsequenced modification and access to}}471 ++s.a + ++s.b; // no-warning472 s.a + ++s.b; // no-warning473 474 ++a + ++s.a; // no-warning475 a + ++s.a; // no-warning476 ++a + ++s.b; // no-warning477 a + ++s.b; // no-warning478 479 // TODO Warn here for bit-fields in the same memory location.480 ++bf1 + ++bf1; // cxx11-warning {{multiple unsequenced modifications to 'bf1'}}481 // cxx17-warning@-1 {{multiple unsequenced modifications to 'bf1'}}482 bf1 + ++bf1; // cxx11-warning {{unsequenced modification and access to 'bf1'}}483 // cxx17-warning@-1 {{unsequenced modification and access to 'bf1'}}484 ++bf1 + ++bf2; // no-warning TODO {{multiple unsequenced modifications to}}485 bf1 + ++bf2; // no-warning TODO {{unsequenced modification and access to}}486 487 // TODO Warn here for bit-fields in the same memory location.488 ++s.bf1 + ++s.bf1; // no-warning TODO {{multiple unsequenced modifications to}}489 s.bf1 + ++s.bf1; // no-warning TODO {{unsequenced modification and access to}}490 ++s.bf1 + ++s.bf2; // no-warning TODO {{multiple unsequenced modifications to}}491 s.bf1 + ++s.bf2; // no-warning TODO {{unsequenced modification and access to}}492 493 ++bf1 + ++s.bf1; // no-warning494 bf1 + ++s.bf1; // no-warning495 ++bf1 + ++s.bf2; // no-warning496 bf1 + ++s.bf2; // no-warning497 498 struct Der : S1 {};499 Der d;500 Der &d_ref = d;501 S1 &s1_ref = d_ref;502 503 ++s1_ref.a + ++d_ref.a; // no-warning TODO {{multiple unsequenced modifications to member 'a' of 'd'}}504 ++s1_ref.a + d_ref.a; // no-warning TODO {{unsequenced modification and access to member 'a' of 'd'}}505 ++s1_ref.a + ++d_ref.b; // no-warning506 ++s1_ref.a + d_ref.b; // no-warning507 508 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}509 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}510 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}511 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}512 ++s.x + x; // no-warning TODO {{unsequenced modification and access to static member 'x' of 'S1'}}513 ++this->x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}514 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}515 ++d_ref.x + ++S1::x; // no-warning TODO {{unsequenced modification and access to static member 'x' of 'S1'}}516}517 518struct S2 {519 union { unsigned x, y; };520 void f2();521};522 523void S2::f2() {524 ++x + ++x; // no-warning TODO {{multiple unsequenced modifications to}}525 x + ++x; // no-warning TODO {{unsequenced modification and access to}}526 ++x + ++y; // no-warning527 x + ++y; // no-warning528}529 530void f2(S2 &s) {531 ++s.x + ++s.x; // no-warning TODO {{multiple unsequenced modifications to}}532 s.x + ++s.x; // no-warning TODO {{unsequenced modification and access to}}533 ++s.x + ++s.y; // no-warning534 s.x + ++s.y; // no-warning535}536 537struct S3 {538 union {539 union {540 unsigned x;541 };542 };543 unsigned y;544 void f3();545};546 547void S3::f3() {548 ++x + ++x; // no-warning TODO {{multiple unsequenced modifications to}}549 x + ++x; // no-warning TODO {{unsequenced modification and access to}}550 ++x + ++y; // no-warning551 x + ++y; // no-warning552}553 554void f3(S3 &s) {555 ++s.x + ++s.x; // no-warning TODO {{multiple unsequenced modifications to}}556 s.x + ++s.x; // no-warning TODO {{unsequenced modification and access to}}557 ++s.x + ++s.y; // no-warning558 s.x + ++s.y; // no-warning559}560 561struct S4 : S3 {562 unsigned y;563 void f4();564};565 566void S4::f4() {567 ++x + ++x; // no-warning TODO {{multiple unsequenced modifications to}}568 x + ++x; // no-warning TODO {{unsequenced modification and access to}}569 ++x + ++y; // no-warning570 x + ++y; // no-warning571 ++S3::y + ++y; // no-warning572 S3::y + ++y; // no-warning573}574 575void f4(S4 &s) {576 ++s.x + ++s.x; // no-warning TODO {{multiple unsequenced modifications to}}577 s.x + ++s.x; // no-warning TODO {{unsequenced modification and access to}}578 ++s.x + ++s.y; // no-warning579 s.x + ++s.y; // no-warning580 ++s.S3::y + ++s.y; // no-warning581 s.S3::y + ++s.y; // no-warning582}583 584static union {585 unsigned Ux;586 unsigned Uy;587};588 589void f5() {590 ++Ux + ++Ux; // no-warning TODO {{multiple unsequenced modifications to}}591 Ux + ++Ux; // no-warning TODO {{unsequenced modification and access to}}592 ++Ux + ++Uy; // no-warning593 Ux + ++Uy; // no-warning594}595 596void f6() {597 struct S { unsigned x, y; } s;598 ++s.x + ++s.x; // no-warning TODO {{multiple unsequenced modifications to}}599 s.x + ++s.x; // no-warning TODO {{unsequenced modification and access to}}600 ++s.x + ++s.y; // no-warning601 s.x + ++s.y; // no-warning602 603 struct { unsigned x, y; } t;604 ++t.x + ++t.x; // no-warning TODO {{multiple unsequenced modifications to}}605 t.x + ++t.x; // no-warning TODO {{unsequenced modification and access to}}606 ++t.x + ++t.y; // no-warning607 t.x + ++t.y; // no-warning608}609 610} // namespace members611 612namespace references {613void reference_f() {614 // TODO: Check that we can see through references.615 // For now this is completely unhandled.616 int a;617 int xs[10];618 int &b = a;619 int &c = b;620 int &ra1 = c;621 int &ra2 = b;622 int other;623 624 ++ra1 + ++ra2; // no-warning TODO {{multiple unsequenced modifications to}}625 ra1 + ++ra2; // no-warning TODO {{unsequenced modification and access to}}626 ++ra1 + ++other; // no-warning627 ra1 + ++other; // no-warning628 629 // Make sure we handle reference cycles.630 int &ref_cycle = ref_cycle;631 ++ref_cycle + ++ref_cycle; // cxx11-warning {{multiple unsequenced modifications to 'ref_cycle'}}632 // cxx17-warning@-1 {{multiple unsequenced modifications to 'ref_cycle'}}633 ref_cycle + ++ref_cycle; // cxx11-warning {{unsequenced modification and access to 'ref_cycle'}}634 // cxx17-warning@-1 {{unsequenced modification and access to 'ref_cycle'}}635}636} // namespace references637 638namespace std {639 using size_t = decltype(sizeof(0));640 template<typename> struct tuple_size;641 template<size_t, typename> struct tuple_element { using type = int; };642}643namespace bindings {644 645 struct A { int x, y; };646 typedef int B[2];647 struct C { template<int> int get(); };648 struct D : A {};649 650} // namespace bindings651template<> struct std::tuple_size<bindings::C> { enum { value = 2 }; };652namespace bindings {653void testa() {654 A a;655 {656 auto [x, y] = a;657 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}658 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}659 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}660 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}661 ++x + ++y; // no-warning662 ++x + y; // no-warning663 ++x + ++a.x; // no-warning664 ++x + a.x; // no-warning665 }666 {667 auto &[x, y] = a;668 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}669 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}670 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}671 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}672 ++x + ++y; // no-warning673 ++x + y; // no-warning674 ++x + ++a.x; // no-warning TODO675 ++x + a.x; // no-warning TODO676 }677}678void testb() {679 B b;680 {681 auto [x, y] = b;682 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}683 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}684 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}685 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}686 ++x + ++y; // no-warning687 ++x + y; // no-warning688 ++x + ++b[0]; // no-warning689 ++x + b[0]; // no-warning690 }691 {692 auto &[x, y] = b;693 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}694 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}695 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}696 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}697 ++x + ++y; // no-warning698 ++x + y; // no-warning699 ++x + ++b[0]; // no-warning TODO700 ++x + b[0]; // no-warning TODO701 }702}703void testc() {704 C c;705 {706 auto [x, y] = c;707 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}708 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}709 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}710 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}711 ++x + ++y; // no-warning712 ++x + y; // no-warning713 }714 {715 auto &[x, y] = c;716 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}717 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}718 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}719 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}720 ++x + ++y; // no-warning721 ++x + y; // no-warning722 }723}724void testd() {725 D d;726 {727 auto [x, y] = d;728 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}729 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}730 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}731 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}732 ++x + ++y; // no-warning733 ++x + y; // no-warning734 ++x + ++d.x; // no-warning735 ++x + d.x; // no-warning736 }737 {738 auto &[x, y] = d;739 ++x + ++x; // cxx11-warning {{multiple unsequenced modifications to 'x'}}740 // cxx17-warning@-1 {{multiple unsequenced modifications to 'x'}}741 ++x + x; // cxx11-warning {{unsequenced modification and access to 'x'}}742 // cxx17-warning@-1 {{unsequenced modification and access to 'x'}}743 ++x + ++y; // no-warning744 ++x + y; // no-warning745 ++x + ++d.x; // no-warning TODO746 ++x + d.x; // no-warning TODO747 }748}749} // namespace bindings750 751namespace templates {752 753template <typename T>754struct Bar {755 T get() { return 0; }756};757 758template <typename X>759struct Foo {760 int Run();761 Bar<int> bar;762};763 764enum E {e1, e2};765bool operator&&(E, E);766 767void foo(int, int);768 769template <typename X>770int Foo<X>::Run() {771 char num = 0;772 773 // Before instantiation, Clang may consider the builtin operator here as774 // unresolved function calls, and treat the arguments as unordered when775 // the builtin operator evaluatation is well-ordered. Waiting until776 // instantiation to check these expressions will prevent false positives.777 if ((num = bar.get()) < 5 && num < 10) { }778 if ((num = bar.get()) < 5 || num < 10) { }779 if (static_cast<E>((num = bar.get()) < 5) || static_cast<E>(num < 10)) { }780 781 if (static_cast<E>((num = bar.get()) < 5) && static_cast<E>(num < 10)) { }782 // cxx11-warning@-1 {{unsequenced modification and access to 'num'}}783 784 foo(num++, num++);785 // cxx11-warning@-1 {{multiple unsequenced modifications to 'num'}}786 // cxx17-warning@-2 {{multiple unsequenced modifications to 'num'}}787 return 1;788}789 790int x = Foo<int>().Run();791// cxx11-note@-1 {{in instantiation of member function 'templates::Foo<int>::Run'}}792// cxx17-note@-2 {{in instantiation of member function 'templates::Foo<int>::Run'}}793 794 795template <typename T>796int Run2() {797 T t = static_cast<T>(0);798 return (t = static_cast<T>(1)) && t;799 // cxx11-warning@-1 {{unsequenced modification and access to 't'}}800}801 802int y = Run2<bool>();803int z = Run2<E>();804// cxx11-note@-1{{in instantiation of function template specialization 'templates::Run2<templates::E>' requested here}}805 806template <typename T> int var = sizeof(T);807void test_var() {808 var<int>++ + var<int>++; // cxx11-warning {{multiple unsequenced modifications to 'var<int>'}}809 // cxx17-warning@-1 {{multiple unsequenced modifications to 'var<int>'}}810 var<int>++ + var<int>; // cxx11-warning {{unsequenced modification and access to 'var<int>'}}811 // cxx17-warning@-1 {{unsequenced modification and access to 'var<int>'}}812 int &r = var<int>;813 r++ + var<int>++; // no-warning TODO {{multiple unsequenced modifications to 'var<int>'}}814 r++ + var<long>++; // no-warning815}816 817} // namespace templates818