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1// RUN: %clang_cc1 -std=c23 -verify -triple x86_64 -pedantic -Wno-conversion -Wno-constant-conversion -Wno-div-by-zero %s2 3// Check that constexpr only applies to variables.4constexpr void f0() {} // expected-error {{'constexpr' can only be used in variable declarations}}5constexpr const int f1() { return 0; } // expected-error {{'constexpr' can only be used in variable declarations}}6 7constexpr struct S1 { int f; }; //expected-error {{struct cannot be marked constexpr}}8constexpr struct S2 ; // expected-error {{struct cannot be marked constexpr}}9constexpr union U1; // expected-error {{union cannot be marked constexpr}}10constexpr union U2 {int a; float b;}; // expected-error {{union cannot be marked constexpr}}11constexpr enum E1 {A = 1, B = 2} ; // expected-error {{enum cannot be marked constexpr}}12struct S3 {13 static constexpr int f = 0; // expected-error {{type name does not allow storage class}}14 // expected-error@-1 {{type name does not allow constexpr}}15 // expected-error@-2 {{expected ';' at end}}16 constexpr int f1 = 0;17 // expected-error@-1 {{type name does not allow constexpr}}18 // expected-error@-2 {{expected ';' at end}}19};20 21constexpr; // expected-error {{'constexpr' can only be used in variable declarations}}22constexpr int V1 = 3;23constexpr float V2 = 7.0;24int V3 = (constexpr)3; // expected-error {{expected expression}}25 26void f2() {27 constexpr int a = 0;28 constexpr float b = 1.7f;29}30 31// Check how constexpr works with other storage-class specifiers.32constexpr auto V4 = 1;33constexpr static auto V5 = 1;34constexpr static const auto V6 = 1;35constexpr static const int V7 = 1;36constexpr static int V8 = 1;37constexpr auto Ulong = 1L;38constexpr auto CompoundLiteral = (int){13};39constexpr auto DoubleCast = (double)(1 / 3);40constexpr auto String = "this is a string"; // expected-error {{constexpr pointer initializer is not null}}41constexpr signed auto Long = 1L; // expected-error {{'auto' cannot be signed or unsigned}}42_Static_assert(_Generic(Ulong, long : 1));43_Static_assert(_Generic(CompoundLiteral, int : 1));44_Static_assert(_Generic(DoubleCast, double : 1));45_Static_assert(_Generic(String, char* : 1));46 47typedef constexpr int Foo; // expected-error {{typedef cannot be constexpr}}48constexpr typedef int Bar; // expected-error {{typedef cannot be constexpr}}49 50void f3(constexpr register int P1) { // expected-error {{function parameter cannot be constexpr}}51 constexpr register int V9 = 0;52 constexpr register auto V10 = 0.0;53}54 55constexpr thread_local int V11 = 38; // expected-error {{cannot combine with previous '_Thread_local' declaration specifier}}56constexpr static thread_local double V12 = 38; // expected-error {{cannot combine with previous '_Thread_local' declaration specifier}}57constexpr extern thread_local char V13; // expected-error {{cannot combine with previous '_Thread_local' declaration specifier}}58// expected-error@-1 {{cannot combine with previous 'extern' declaration specifier}}59// expected-error@-2 {{constexpr variable declaration must be a definition}}60constexpr thread_local short V14 = 38; // expected-error {{cannot combine with previous '_Thread_local' declaration specifier}}61 62// Check how constexpr works with qualifiers.63constexpr _Atomic int V15 = 0; // expected-error {{constexpr variable cannot have type 'const _Atomic(int)'}}64constexpr _Atomic(int) V16 = 0; // expected-error {{constexpr variable cannot have type 'const _Atomic(int)'}}65 66constexpr volatile int V17 = 0; // expected-error {{constexpr variable cannot have type 'const volatile int'}}67 68constexpr int * restrict V18 = 0; // expected-error {{constexpr variable cannot have type 'int *const restrict'}}69 70constexpr extern char Oops = 1; // expected-error {{cannot combine with previous 'extern' declaration specifier}} \71 // expected-warning {{'extern' variable has an initializer}}72 73constexpr int * restrict * Oops1 = 0;74 75typedef _Atomic(int) TheA;76typedef volatile short TheV;77typedef float * restrict TheR;78 79constexpr TheA V19[3] = {};80// expected-error@-1 {{constexpr variable cannot have type 'const TheA[3]' (aka 'const _Atomic(int)[3]')}}81constexpr TheV V20[3] = {};82// expected-error@-1 {{constexpr variable cannot have type 'const TheV[3]' (aka 'const volatile short[3]')}}83constexpr TheR V21[3] = {};84// expected-error@-1 {{constexpr variable cannot have type 'const TheR[3]' (aka 'float *restrict const[3]')}}85 86struct HasA {87 TheA f;88 int b;89};90 91struct HasV {92 float b;93 TheV f;94};95 96struct HasR {97 short b;98 int a;99 TheR f;100};101 102constexpr struct HasA V22[2] = {};103// expected-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}}104constexpr struct HasV V23[2] = {};105// expected-error@-1 {{constexpr variable cannot have type 'TheV' (aka 'volatile short')}}106constexpr struct HasR V24[2] = {};107// expected-error@-1 {{constexpr variable cannot have type 'TheR' (aka 'float *restrict')}}108 109union U3 {110 float a;111 union {112 struct HasA f;113 struct HasR f1;114 };115};116 117constexpr union U3 V25 = {};118// expected-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}}119constexpr union U3 V26[8] = {};120// expected-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}}121 122struct S4 {123 union U3 f[3];124};125 126constexpr struct S4 V27 = {};127// expected-error@-1 {{constexpr variable cannot have type 'TheA' (aka '_Atomic(int)')}}128constexpr const int V28 = 28;129 130struct S {131 union {132 volatile int i;133 };134 int j;135};136 137constexpr struct S s = {}; // expected-error {{constexpr variable cannot have type 'volatile int'}}138 139// Check that constexpr variable must have a valid initializer which is a140// constant expression.141constexpr int V29;142// expected-error@-1 {{constexpr variable 'V29' must be initialized by a constant expression}}143 144struct S5 {145 int f;146};147 148constexpr struct S5 V30;149// expected-error@-1 {{constexpr variable 'V30' must be initialized by a constant expression}}150constexpr struct S5 V31 = {};151 152int randomFoo() { return 7; }153 154constexpr float V32 = randomFoo();155// expected-error@-1 {{constexpr variable 'V32' must be initialized by a constant expression}}156 157const int V33 = 4;158const int V34 = 0;159const int V35 = 2;160 161constexpr int V36 = V33 / V34;162// expected-error@-1 {{constexpr variable 'V36' must be initialized by a constant expression}}163constexpr int V37 = V33 / V35;164// expected-error@-1 {{constexpr variable 'V37' must be initialized by a constant expression}}165constexpr int V38 = 3;166constexpr int V39 = V38 / V38;167constexpr int V40 = V38 / 2;168constexpr int V41 = V38 / 0;169// expected-error@-1 {{constexpr variable 'V41' must be initialized by a constant expression}}170// expected-note@-2 {{division by zero}}171constexpr int V42 = V38 & 0;172 173constexpr struct S5 V43 = { randomFoo() };174// expected-error@-1 {{constexpr variable 'V43' must be initialized by a constant expression}}175constexpr struct S5 V44 = { 0 };176constexpr struct S5 V45 = { V38 / 0 };177// expected-error@-1 {{constexpr variable 'V45' must be initialized by a constant expression}}178// expected-note@-2 {{division by zero}}179 180constexpr float V46[3] = {randomFoo() };181// expected-error@-1 {{constexpr variable 'V46' must be initialized by a constant expression}}182constexpr struct S5 V47[3] = {randomFoo() };183// expected-error@-1 {{constexpr variable 'V47' must be initialized by a constant expression}}184 185const static int V48 = V38;186constexpr static int V49 = V48;187// expected-error@-1 {{constexpr variable 'V49' must be initialized by a constant expression}}188 189void f4(const int P1) {190 constexpr int V = P1;191// expected-error@-1 {{constexpr variable 'V' must be initialized by a constant expression}}192 193 constexpr int V1 = 12;194 constexpr const int *V2 = &V1;195// expected-error@-1 {{constexpr variable 'V2' must be initialized by a constant expression}}196}197 198// Check that initializer for constexpr variable should match the type of the199// variable and is exactly representable int the variable's type.200 201struct S6 {202 unsigned char a;203};204 205struct S7 {206 union {207 float a;208 };209 unsigned int b;210};211 212struct S8 {213 unsigned char a[3];214 unsigned int b[3];215};216 217constexpr struct S8 DesigInit = {.b = {299, 7, 8}, .a = {-1, 7, 8}};218// expected-error@-1 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'unsigned char'}}219 220void f5() {221 constexpr char V50 = 300;222 // expected-error@-1 {{constexpr initializer evaluates to 300 which is not exactly representable in type 'const char'}}223 constexpr float V51 = 1.0 / 3.0;224 // expected-error@-1 {{constexpr initializer evaluates to 3.333333e-01 which is not exactly representable in type 'const float'}}225 constexpr float V52 = 0.7;226 // expected-error@-1 {{constexpr initializer evaluates to 7.000000e-01 which is not exactly representable in type 'const float'}}227 constexpr float V53 = 1.0f / 3.0f;228 constexpr float V54 = 432000000000;229 // expected-error@-1 {{constexpr initializer evaluates to 432000000000 which is not exactly representable in type 'const float'}}230 constexpr unsigned char V55[] = {231 "\xAF",232 // expected-error@-1 {{constexpr initializer evaluates to -81 which is not exactly representable in type 'const unsigned char'}}233 };234 235 constexpr unsigned char V56[] = {236 u8"\xAF",237 };238 constexpr struct S6 V57 = {299};239 // expected-error@-1 {{constexpr initializer evaluates to 299 which is not exactly representable in type 'unsigned char'}}240 constexpr struct S6 V58 = {-299};241 // expected-error@-1 {{constexpr initializer evaluates to -299 which is not exactly representable in type 'unsigned char'}}242 constexpr double V59 = 0.5;243 constexpr double V60 = 1.0;244 constexpr float V61 = V59 / V60;245 constexpr double V62 = 1.7;246 constexpr float V63 = V59 / V62;247 // expected-error@-1 {{constexpr initializer evaluates to 2.941176e-01 which is not exactly representable in type 'const float'}}248 249 constexpr unsigned char V64 = '\xAF';250 // expected-error@-1 {{constexpr initializer evaluates to -81 which is not exactly representable in type 'const unsigned char'}}251 constexpr unsigned char V65 = u8'\xAF';252 253 constexpr char V66[3] = {300};254 // expected-error@-1 {{constexpr initializer evaluates to 300 which is not exactly representable in type 'const char'}}255 constexpr struct S6 V67[3] = {300};256 // expected-error@-1 {{constexpr initializer evaluates to 300 which is not exactly representable in type 'unsigned char'}}257 258 constexpr struct S7 V68 = {0.3, -1 };259 // expected-error@-1 {{constexpr initializer evaluates to 3.000000e-01 which is not exactly representable in type 'float'}}260 // expected-error@-2 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'unsigned int'}}261 constexpr struct S7 V69 = {0.5, -1 };262 // expected-error@-1 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'unsigned int'}}263 constexpr struct S7 V70[3] = {{123456789}};264 // expected-error@-1 {{constexpr initializer evaluates to 123456789 which is not exactly representable in type 'float'}}265 266 constexpr int V71 = 0.3;267 // expected-error@-1 {{constexpr initializer for type 'const int' is of type 'double'}}268 constexpr int V72 = V59;269 // expected-error@-1 {{constexpr initializer for type 'const int' is of type 'const double'}}270 constexpr struct S6 V73 = {V59};271 // expected-error@-1 {{constexpr initializer for type 'unsigned char' is of type 'const double'}}272 273 constexpr float V74 = 1;274 constexpr float V75 = V59;275 constexpr unsigned int V76[3] = {0.5};276 // expected-error@-1 {{constexpr initializer for type 'const unsigned int' is of type 'double'}}277 278 constexpr _Complex float V77 = 0;279 constexpr float V78 = V77;280 // expected-error@-1 {{constexpr initializer for type 'const float' is of type 'const _Complex float'}}281 constexpr int V79 = V77;282 // expected-error@-1 {{constexpr initializer for type 'const int' is of type 'const _Complex float'}}283 284}285 286constexpr char string[] = "test""ing this out\xFF";287constexpr unsigned char ustring[] = "test""ing this out\xFF";288// expected-error@-1 {{constexpr initializer evaluates to -1 which is not exactly representable in type 'const unsigned char'}}289constexpr char u8string[] = u8"test"u8"ing this out\xFF";290// expected-error@-1 {{constexpr initializer evaluates to 255 which is not exactly representable in type 'const char'}}291constexpr unsigned char u8ustring[] = u8"test"u8"ing this out\xFF";292constexpr unsigned short uustring[] = u"test"u"ing this out\xFF";293constexpr unsigned int Ustring[] = U"test"U"ing this out\xFF";294constexpr unsigned char Arr2[6][6] = {295 {"ek\xFF"}, {"ek\xFF"}296// expected-error@-1 2{{constexpr initializer evaluates to -1 which is not exactly representable in type 'const unsigned char'}}297};298 299constexpr int i = (12);300constexpr int j = (i);301constexpr unsigned jneg = (-i);302// expected-error@-1 {{constexpr initializer evaluates to -12 which is not exactly representable in type 'const unsigned int'}}303 304// Check that initializer for pointer constexpr variable should be null.305constexpr int V80 = 3;306constexpr const int *V81 = &V80;307// expected-error@-1 {{constexpr pointer initializer is not null}}308constexpr int *V82 = 0;309constexpr int *V83 = V82;310constexpr int *V84 = 42;311// expected-error@-1 {{constexpr variable 'V84' must be initialized by a constant expression}}312// expected-note@-2 {{this conversion is not allowed in a constant expression}}313// expected-error@-3 {{constexpr pointer initializer is not null}}314constexpr int *V85 = nullptr;315 316// Check that constexpr variables should not be VLAs.317void f6(const int P1) {318 constexpr int V86[P1] = {};319// expected-error@-1 {{constexpr variable cannot have type 'const int[P1]'}}320 const int V87 = 3;321 constexpr int V88[V87] = {};322// expected-warning@-1 {{variable length array folded to constant array as an extension}}323 int V89 = 7;324 constexpr int V90[V89] = {};325// expected-error@-1 {{constexpr variable cannot have type 'const int[V89]'}}326}327 328void f7(int n, int array[n]) {329 constexpr typeof(array) foo = 0; // Accepted because array is a pointer type, not a VLA type330 int (*(*fp)(int n))[n];331 constexpr typeof(fp) bar = 0; // expected-error {{constexpr variable cannot have type 'const typeof (fp)' (aka 'int (*(*const)(int))[n]')}}332}333 334// Check how constexpr works with NaNs and infinities.335#define FLT_NAN __builtin_nanf("1")336#define DBL_NAN __builtin_nan("1")337#define LD_NAN __builtin_nanf("1")338#define FLT_SNAN __builtin_nansf("1")339#define DBL_SNAN __builtin_nans("1")340#define LD_SNAN __builtin_nansl("1")341#define INF __builtin_inf()342void infsNaNs() {343 // Inf and quiet NaN is always fine, signaling NaN must have the same type.344 constexpr float fl0 = INF;345 constexpr float fl1 = (long double)INF;346 constexpr float fl2 = (long double)FLT_NAN;347 constexpr float fl3 = FLT_NAN;348 constexpr float fl5 = DBL_NAN;349 constexpr float fl6 = LD_NAN;350 constexpr float fl7 = DBL_SNAN; // expected-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const float'}}351 constexpr float fl8 = LD_SNAN; // expected-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const float'}}352 353 constexpr double db0 = FLT_NAN;354 constexpr double db2 = DBL_NAN;355 constexpr double db3 = DBL_SNAN;356 constexpr double db4 = FLT_SNAN; // expected-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const double'}}357 constexpr double db5 = LD_SNAN; // expected-error {{constexpr initializer evaluates to nan which is not exactly representable in type 'const double'}}358 constexpr double db6 = INF;359}360 361constexpr struct S9 s9 = { }; // expected-error {{variable has incomplete type 'const struct S9'}} \362 // expected-note {{forward declaration of 'struct S9'}}363 364struct S10 {365 signed long long i : 8;366};367constexpr struct S10 c = { 255 };368// FIXME-expected-error@-1 {{constexpr initializer evaluates to 255 which is not exactly representable in 'long long' bit-field with width 8}}369// See: GH#101299370 371void constexprif() {372 if constexpr (300) {} //expected-error {{expected '(' after 'if'}}373}374void constevalif() {375 if consteval (300) {} //expected-error {{expected '(' after 'if'}}376}377 378struct S11 {379 int len;380};381void ghissue112516() {382 struct S11 *s11 = 0;383 constexpr int num = s11->len; // expected-error {{constexpr variable 'num' must be initialized by a constant expression}}384 void *Arr[num];385}386 387void ghissue109095() {388 constexpr char c[] = { 'a' };389 constexpr int i = c[1]; // expected-error {{constexpr variable 'i' must be initialized by a constant expression}}\390 // expected-note {{declared here}}391 _Static_assert(i == c[0]); // expected-error {{static assertion expression is not an integral constant expression}}\392 // expected-note {{initializer of 'i' is not a constant expression}}393}394 395typedef bool __vbool2 __attribute__((ext_vector_type(2)));396typedef short v2int16_t __attribute__((ext_vector_type(2)));397 398bool issue155507(v2int16_t a, v2int16_t b) {399 return __builtin_bit_cast(unsigned char, __builtin_convertvector(a == b, __vbool2)) == 0b11;400}401 402constexpr bool b2 = (bool)nullptr;403_Static_assert(!b2);404