1 // RUN: %clang_cc1 -std=c23 -verify=ref,both -triple x86_64 -pedantic -Wno-conversion -Wno-constant-conversion -Wno-div-by-zero %s 2 // RUN: %clang_cc1 -std=c23 -verify=expected,both -triple x86_64 -pedantic -Wno-conversion -Wno-constant-conversion -Wno-div-by-zero -fexperimental-new-constant-interpreter %s 3 4 // Check that constexpr only applies to variables. 5 constexpr void f0() {} // both-error {{'constexpr' can only be used in variable declarations}} 6 constexpr const int f1() { return 0; } // both-error {{'constexpr' can only be used in variable declarations}} 7 8 constexpr struct S1 { int f; }; //both-error {{struct cannot be marked constexpr}} 9 constexpr struct S2 ; // both-error {{struct cannot be marked constexpr}} 10 constexpr union U1; // both-error {{union cannot be marked constexpr}} 11 constexpr union U2 {int a; float b;}; // both-error {{union cannot be marked constexpr}} 12 constexpr enum E1 {A = 1, B = 2} ; // both-error {{enum cannot be marked constexpr}} 13 struct S3 { 14 static constexpr int f = 0; // both-error {{type name does not allow storage class}} 15 // both-error@-1 {{type name does not allow constexpr}} 16 // both-error@-2 {{expected ';' at end}} 17 constexpr int f1 = 0; 18 // both-error@-1 {{type name does not allow constexpr}} 19 // both-error@-2 {{expected ';' at end}} 20 }; 21 22 constexpr; // both-error {{'constexpr' can only be used in variable declarations}} 23 constexpr int V1 = 3; 24 constexpr float V2 = 7.0; 25 int V3 = (constexpr)3; // both-error {{expected expression}} 26 27 void f2() { 28 constexpr int a = 0; 29 constexpr float b = 1.7f; 30 } 31 32 // Check how constexpr works with other storage-class specifiers. 33 constexpr auto V4 = 1; 34 constexpr static auto V5 = 1; 35 constexpr static const auto V6 = 1; 36 constexpr static const int V7 = 1; 37 constexpr static int V8 = 1; 38 constexpr auto Ulong = 1L; 39 constexpr auto CompoundLiteral = (int){13}; 40 constexpr auto DoubleCast = (double)(1 / 3); 41 constexpr auto String = "this is a string"; // both-error {{constexpr pointer initializer is not null}} 42 constexpr signed auto Long = 1L; // both-error {{'auto' cannot be signed or unsigned}} 43 _Static_assert(_Generic(Ulong, long : 1)); 44 _Static_assert(_Generic(CompoundLiteral, int : 1)); 45 _Static_assert(_Generic(DoubleCast, double : 1)); 46 _Static_assert(_Generic(String, char* : 1)); 47 48 typedef constexpr int Foo; // both-error {{typedef cannot be constexpr}} 49 constexpr typedef int Bar; // both-error {{typedef cannot be constexpr}} 50 51 void f3(constexpr register int P1) { // both-error {{function parameter cannot be constexpr}} 52 constexpr register int V9 = 0; 53 constexpr register auto V10 = 0.0; 54 } 55 56 constexpr thread_local int V11 = 38; // both-error {{cannot combine with previous '_Thread_local' declaration specifier}} 57 constexpr static thread_local double V12 = 38; // both-error {{cannot combine with previous '_Thread_local' declaration specifier}} 58 constexpr extern thread_local char V13; // both-error {{cannot combine with previous '_Thread_local' declaration specifier}} 59 // both-error@-1 {{cannot combine with previous 'extern' declaration specifier}} 60 // both-error@-2 {{constexpr variable declaration must be a definition}} 61 constexpr thread_local short V14 = 38; // both-error {{cannot combine with previous '_Thread_local' declaration specifier}} 62 63 // Check how constexpr works with qualifiers. 64 constexpr _Atomic int V15 = 0; // both-error {{constexpr variable cannot have type 'const _Atomic(int)'}} 65 constexpr _Atomic(int) V16 = 0; // both-error {{constexpr variable cannot have type 'const _Atomic(int)'}} 66 67 constexpr volatile int V17 = 0; // both-error {{constexpr variable cannot have type 'const volatile int'}} 68 69 constexpr int * restrict V18 = 0; // both-error {{constexpr variable cannot have type 'int *const restrict'}} 70 71 constexpr extern char Oops = 1; // both-error {{cannot combine with previous 'extern' declaration specifier}} \ 72 // both-warning {{'extern' variable has an initializer}} 73 74 constexpr int * restrict * Oops1 = 0; 75 76 typedef _Atomic(int) TheA; 77 typedef volatile short TheV; 78 typedef float * restrict TheR; 79 80 constexpr TheA V19[3] = {}; 81 // both-error@-1 {{constexpr variable cannot have type 'const TheA[3]' (aka 'const _Atomic(int)[3]')}} 82 constexpr TheV V20[3] = {}; 83 // both-error@-1 {{constexpr variable cannot have type 'const TheV[3]' (aka 'const volatile short[3]')}} 84 constexpr TheR V21[3] = {}; 85 // both-error@-1 {{constexpr variable cannot have type 'const TheR[3]' (aka 'float *restrict const[3]')}} 86 87 struct HasA { 88 TheA f; 89 int b; 90 }; 91 92 struct HasV { 93 float b; 94 TheV f; 95 }; 96 97 struct HasR { 98 short b; 99 int a; 100 TheR f; 101 }; 102 103 constexpr struct HasA V22[2] = {}; 104 // both-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}} 105 constexpr struct HasV V23[2] = {}; 106 // both-error@-1 {{constexpr variable cannot have type 'TheV' (aka 'volatile short')}} 107 constexpr struct HasR V24[2] = {}; 108 // both-error@-1 {{constexpr variable cannot have type 'TheR' (aka 'float *restrict')}} 109 110 union U3 { 111 float a; 112 union { 113 struct HasA f; 114 struct HasR f1; 115 }; 116 }; 117 118 constexpr union U3 V25 = {}; 119 // both-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}} 120 constexpr union U3 V26[8] = {}; 121 // both-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}} 122 123 struct S4 { 124 union U3 f[3]; 125 }; 126 127 constexpr struct S4 V27 = {}; 128 // both-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}} 129 constexpr const int V28 = 28; 130 131 struct S { 132 union { 133 volatile int i; 134 }; 135 int j; 136 }; 137 138 constexpr struct S s = {}; // both-error {{constexpr variable cannot have type 'volatile int'}} 139 140 // Check that constexpr variable must have a valid initializer which is a 141 // constant expression. 142 constexpr int V29; 143 // both-error@-1 {{constexpr variable 'V29' must be initialized by a constant expression}} 144 145 struct S5 { 146 int f; 147 }; 148 149 constexpr struct S5 V30; 150 // both-error@-1 {{constexpr variable 'V30' must be initialized by a constant expression}} 151 constexpr struct S5 V31 = {}; 152 153 int randomFoo() { return 7; } 154 155 constexpr float V32 = randomFoo(); 156 // both-error@-1 {{constexpr variable 'V32' must be initialized by a constant expression}} 157 158 const int V33 = 4; 159 const int V34 = 0; 160 const int V35 = 2; 161 162 constexpr int V36 = V33 / V34; 163 // both-error@-1 {{constexpr variable 'V36' must be initialized by a constant expression}} 164 constexpr int V37 = V33 / V35; 165 // both-error@-1 {{constexpr variable 'V37' must be initialized by a constant expression}} 166 constexpr int V38 = 3; 167 constexpr int V39 = V38 / V38; 168 constexpr int V40 = V38 / 2; 169 constexpr int V41 = V38 / 0; 170 // both-error@-1 {{constexpr variable 'V41' must be initialized by a constant expression}} 171 // both-note@-2 {{division by zero}} 172 constexpr int V42 = V38 & 0; 173 174 constexpr struct S5 V43 = { randomFoo() }; 175 // both-error@-1 {{constexpr variable 'V43' must be initialized by a constant expression}} 176 constexpr struct S5 V44 = { 0 }; 177 constexpr struct S5 V45 = { V38 / 0 }; 178 // both-error@-1 {{constexpr variable 'V45' must be initialized by a constant expression}} 179 // both-note@-2 {{division by zero}} 180 181 constexpr float V46[3] = {randomFoo() }; 182 // both-error@-1 {{constexpr variable 'V46' must be initialized by a constant expression}} 183 constexpr struct S5 V47[3] = {randomFoo() }; 184 // both-error@-1 {{constexpr variable 'V47' must be initialized by a constant expression}} 185 186 const static int V48 = V38; 187 constexpr static int V49 = V48; 188 // both-error@-1 {{constexpr variable 'V49' must be initialized by a constant expression}} 189 190 void f4(const int P1) { 191 constexpr int V = P1; 192 // both-error@-1 {{constexpr variable 'V' must be initialized by a constant expression}} 193 194 constexpr int V1 = 12; 195 constexpr const int *V2 = &V1; 196 // both-error@-1 {{constexpr variable 'V2' must be initialized by a constant expression}} 197 } 198 199 // Check that initializer for constexpr variable should match the type of the 200 // variable and is exactly representable int the variable's type. 201 202 struct S6 { 203 unsigned char a; 204 }; 205 206 struct S7 { 207 union { 208 float a; 209 }; 210 unsigned int b; 211 }; 212 213 struct S8 { 214 unsigned char a[3]; 215 unsigned int b[3]; 216 }; 217 218 constexpr struct S8 DesigInit = {.b = {299, 7, 8}, .a = {-1, 7, 8}}; 219 // both-error@-1 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'unsigned char'}} 220 221 void f5() { 222 constexpr char V50 = 300; 223 // both-error@-1 {{constexpr initializer evaluates to 300 which is not exactly representable in type 'const char'}} 224 constexpr float V51 = 1.0 / 3.0; 225 // both-error@-1 {{constexpr initializer evaluates to 3.333333e-01 which is not exactly representable in type 'const float'}} 226 constexpr float V52 = 0.7; 227 // both-error@-1 {{constexpr initializer evaluates to 7.000000e-01 which is not exactly representable in type 'const float'}} 228 constexpr float V53 = 1.0f / 3.0f; 229 constexpr float V54 = 432000000000; 230 // both-error@-1 {{constexpr initializer evaluates to 432000000000 which is not exactly representable in type 'const float'}} 231 constexpr unsigned char V55[] = { 232 "\xAF", 233 // both-error@-1 {{constexpr initializer evaluates to -81 which is not exactly representable in type 'const unsigned char'}} 234 }; 235 236 constexpr unsigned char V56[] = { 237 u8"\xAF", 238 }; 239 constexpr struct S6 V57 = {299}; 240 // both-error@-1 {{constexpr initializer evaluates to 299 which is not exactly representable in type 'unsigned char'}} 241 constexpr struct S6 V58 = {-299}; 242 // both-error@-1 {{constexpr initializer evaluates to -299 which is not exactly representable in type 'unsigned char'}} 243 constexpr double V59 = 0.5; 244 constexpr double V60 = 1.0; 245 constexpr float V61 = V59 / V60; 246 constexpr double V62 = 1.7; 247 constexpr float V63 = V59 / V62; 248 // both-error@-1 {{constexpr initializer evaluates to 2.941176e-01 which is not exactly representable in type 'const float'}} 249 250 constexpr unsigned char V64 = '\xAF'; 251 // both-error@-1 {{constexpr initializer evaluates to -81 which is not exactly representable in type 'const unsigned char'}} 252 constexpr unsigned char V65 = u8'\xAF'; 253 254 constexpr char V66[3] = {300}; 255 // both-error@-1 {{constexpr initializer evaluates to 300 which is not exactly representable in type 'const char'}} 256 constexpr struct S6 V67[3] = {300}; 257 // both-error@-1 {{constexpr initializer evaluates to 300 which is not exactly representable in type 'unsigned char'}} 258 259 constexpr struct S7 V68 = {0.3, -1 }; 260 // both-error@-1 {{constexpr initializer evaluates to 3.000000e-01 which is not exactly representable in type 'float'}} 261 // both-error@-2 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'unsigned int'}} 262 constexpr struct S7 V69 = {0.5, -1 }; 263 // both-error@-1 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'unsigned int'}} 264 constexpr struct S7 V70[3] = {{123456789}}; 265 // both-error@-1 {{constexpr initializer evaluates to 123456789 which is not exactly representable in type 'float'}} 266 267 constexpr int V71 = 0.3; 268 // both-error@-1 {{constexpr initializer for type 'const int' is of type 'double'}} 269 constexpr int V72 = V59; 270 // both-error@-1 {{constexpr initializer for type 'const int' is of type 'const double'}} 271 constexpr struct S6 V73 = {V59}; 272 // both-error@-1 {{constexpr initializer for type 'unsigned char' is of type 'const double'}} 273 274 constexpr float V74 = 1; 275 constexpr float V75 = V59; 276 constexpr unsigned int V76[3] = {0.5}; 277 // both-error@-1 {{constexpr initializer for type 'const unsigned int' is of type 'double'}} 278 279 constexpr _Complex float V77 = 0; 280 constexpr float V78 = V77; 281 // both-error@-1 {{constexpr initializer for type 'const float' is of type 'const _Complex float'}} 282 constexpr int V79 = V77; 283 // both-error@-1 {{constexpr initializer for type 'const int' is of type 'const _Complex float'}} 284 285 } 286 287 constexpr char string[] = "test""ing this out\xFF"; 288 constexpr unsigned char ustring[] = "test""ing this out\xFF"; 289 // both-error@-1 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'const unsigned char'}} 290 constexpr char u8string[] = u8"test"u8"ing this out\xFF"; 291 // both-error@-1 {{constexpr initializer evaluates to 255 which is not exactly representable in type 'const char'}} 292 constexpr unsigned char u8ustring[] = u8"test"u8"ing this out\xFF"; 293 constexpr unsigned short uustring[] = u"test"u"ing this out\xFF"; 294 constexpr unsigned int Ustring[] = U"test"U"ing this out\xFF"; 295 constexpr unsigned char Arr2[6][6] = { 296 {"ek\xFF"}, {"ek\xFF"} 297 // both-error@-1 2{{constexpr initializer evaluates to -1 which is not exactly representable in type 'const unsigned char'}} 298 }; 299 300 constexpr int i = (12); 301 constexpr int j = (i); 302 constexpr unsigned jneg = (-i); 303 // both-error@-1 {{constexpr initializer evaluates to -12 which is not exactly representable in type 'const unsigned int'}} 304 305 // Check that initializer for pointer constexpr variable should be null. 306 constexpr int V80 = 3; 307 constexpr const int *V81 = &V80; 308 // both-error@-1 {{constexpr pointer initializer is not null}} 309 constexpr int *V82 = 0; 310 constexpr int *V83 = V82; 311 constexpr int *V84 = 42; 312 // both-error@-1 {{constexpr variable 'V84' must be initialized by a constant expression}} 313 // both-note@-2 {{this conversion is not allowed in a constant expression}} 314 // both-error@-3 {{constexpr pointer initializer is not null}} 315 constexpr int *V85 = nullptr; 316 317 // Check that constexpr variables should not be VLAs. 318 void f6(const int P1) { 319 constexpr int V86[P1] = {}; 320 // both-error@-1 {{constexpr variable cannot have type 'const int[P1]'}} 321 const int V87 = 3; 322 constexpr int V88[V87] = {}; 323 // both-warning@-1 {{variable length array folded to constant array as an extension}} 324 int V89 = 7; 325 constexpr int V90[V89] = {}; 326 // both-error@-1 {{constexpr variable cannot have type 'const int[V89]'}} 327 } 328 329 void f7(int n, int array[n]) { 330 constexpr typeof(array) foo = 0; // Accepted because array is a pointer type, not a VLA type 331 int (*(*fp)(int n))[n]; 332 constexpr typeof(fp) bar = 0; // both-error {{constexpr variable cannot have type 'const typeof (fp)' (aka 'int (*(*const)(int))[n]')}} 333 } 334 335 // Check how constexpr works with NaNs and infinities. 336 #define FLT_NAN __builtin_nanf("1") 337 #define DBL_NAN __builtin_nan("1") 338 #define LD_NAN __builtin_nanf("1") 339 #define FLT_SNAN __builtin_nansf("1") 340 #define DBL_SNAN __builtin_nans("1") 341 #define LD_SNAN __builtin_nansl("1") 342 #define INF __builtin_inf() 343 void infsNaNs() { 344 // Inf and quiet NaN is always fine, signaling NaN must have the same type. 345 constexpr float fl0 = INF; 346 constexpr float fl1 = (long double)INF; 347 constexpr float fl2 = (long double)FLT_NAN; 348 constexpr float fl3 = FLT_NAN; 349 constexpr float fl5 = DBL_NAN; 350 constexpr float fl6 = LD_NAN; 351 constexpr float fl7 = DBL_SNAN; // both-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const float'}} 352 constexpr float fl8 = LD_SNAN; // both-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const float'}} 353 354 constexpr double db0 = FLT_NAN; 355 constexpr double db2 = DBL_NAN; 356 constexpr double db3 = DBL_SNAN; 357 constexpr double db4 = FLT_SNAN; // both-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const double'}} 358 constexpr double db5 = LD_SNAN; // both-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const double'}} 359 constexpr double db6 = INF; 360 } 361 362 constexpr struct S9 s9 = { }; // both-error {{variable has incomplete type 'const struct S9'}} \ 363 // both-note {{forward declaration of 'struct S9'}} 364 365 struct S10 { 366 signed long long i : 8; 367 }; 368 constexpr struct S10 c = { 255 }; 369 // FIXME-expected-error@-1 {{constexpr initializer evaluates to 255 which is not exactly representable in 'long long' bit-field with width 8}} 370 // See: GH#101299 371