1 // RUN: %clang_cc1 %s -triple x86_64-linux-gnu -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension 2 // RUN: %clang_cc1 %s -triple x86_64-linux-gnu -std=gnu++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -DGNUMODE 3 // RUN: %clang_cc1 %s -triple x86_64-linux-gnu -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -fno-signed-char 4 // RUN: %clang_cc1 %s -triple x86_64-linux-gnu -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -fno-wchar -DNO_PREDEFINED_WCHAR_T 5 // RUN: %clang_cc1 %s -triple armebv7-unknown-linux -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension 6 // RUN: %clang_cc1 %s -triple armebv7-unknown-linux -std=gnu++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -DGNUMODE 7 // RUN: %clang_cc1 %s -triple armebv7-unknown-linux -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -fno-signed-char 8 // RUN: %clang_cc1 %s -triple armebv7-unknown-linux -std=c++2a -fsyntax-only -verify -pedantic -Wno-vla-extension -fno-wchar -DNO_PREDEFINED_WCHAR_T 9 10 # 9 "/usr/include/string.h" 1 3 4 11 extern "C" { 12 typedef decltype(sizeof(int)) size_t; 13 14 extern size_t strlen(const char *p); 15 16 extern int strcmp(const char *s1, const char *s2); 17 extern int strncmp(const char *s1, const char *s2, size_t n); 18 extern int memcmp(const void *s1, const void *s2, size_t n); 19 20 #ifdef GNUMODE 21 extern int bcmp(const void *s1, const void *s2, size_t n); 22 #endif 23 24 extern char *strchr(const char *s, int c); 25 extern void *memchr(const void *s, int c, size_t n); 26 27 extern void *memcpy(void *d, const void *s, size_t n); 28 extern void *memmove(void *d, const void *s, size_t n); 29 } 30 # 25 "SemaCXX/constexpr-string.cpp" 2 31 32 # 27 "/usr/include/wchar.h" 1 3 4 33 extern "C" { 34 #if NO_PREDEFINED_WCHAR_T 35 typedef decltype(L'0') wchar_t; 36 #endif 37 extern size_t wcslen(const wchar_t *p); 38 39 extern int wcscmp(const wchar_t *s1, const wchar_t *s2); 40 extern int wcsncmp(const wchar_t *s1, const wchar_t *s2, size_t n); 41 extern int wmemcmp(const wchar_t *s1, const wchar_t *s2, size_t n); 42 43 extern wchar_t *wcschr(const wchar_t *s, wchar_t c); 44 extern wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n); 45 46 extern wchar_t *wmemcpy(wchar_t *d, const wchar_t *s, size_t n); 47 extern wchar_t *wmemmove(wchar_t *d, const wchar_t *s, size_t n); 48 } 49 50 # 45 "SemaCXX/constexpr-string.cpp" 2 51 namespace Strlen { 52 constexpr int n = __builtin_strlen("hello"); // ok 53 static_assert(n == 5); 54 constexpr int wn = __builtin_wcslen(L"hello"); // ok 55 static_assert(wn == 5); 56 constexpr int m = strlen("hello"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strlen' cannot be used in a constant expression}} 57 constexpr int wm = wcslen(L"hello"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wcslen' cannot be used in a constant expression}} 58 59 // Make sure we can evaluate a call to strlen. 60 int arr[3]; // expected-note 2{{here}} 61 int k = arr[strlen("hello")]; // expected-warning {{array index 5}} 62 int wk = arr[wcslen(L"hello")]; // expected-warning {{array index 5}} 63 } 64 65 namespace StrcmpEtc { 66 constexpr char kFoobar[6] = {'f','o','o','b','a','r'}; 67 constexpr char kFoobazfoobar[12] = {'f','o','o','b','a','z','f','o','o','b','a','r'}; 68 69 static_assert(__builtin_strcmp("abab", "abab") == 0); 70 static_assert(__builtin_strcmp("abab", "abba") == -1); 71 static_assert(__builtin_strcmp("abab", "abaa") == 1); 72 static_assert(__builtin_strcmp("ababa", "abab") == 1); 73 static_assert(__builtin_strcmp("abab", "ababa") == -1); 74 static_assert(__builtin_strcmp("a\203", "a") == 1); 75 static_assert(__builtin_strcmp("a\203", "a\003") == 1); 76 static_assert(__builtin_strcmp("abab\0banana", "abab") == 0); 77 static_assert(__builtin_strcmp("abab", "abab\0banana") == 0); 78 static_assert(__builtin_strcmp("abab\0banana", "abab\0canada") == 0); 79 static_assert(__builtin_strcmp(0, "abab") == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 80 static_assert(__builtin_strcmp("abab", 0) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 81 82 static_assert(__builtin_strcmp(kFoobar, kFoobazfoobar) == -1); // FIXME: Should we reject this? 83 static_assert(__builtin_strcmp(kFoobar, kFoobazfoobar + 6) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 84 85 static_assert(__builtin_strncmp("abaa", "abba", 5) == -1); 86 static_assert(__builtin_strncmp("abaa", "abba", 4) == -1); 87 static_assert(__builtin_strncmp("abaa", "abba", 3) == -1); 88 static_assert(__builtin_strncmp("abaa", "abba", 2) == 0); 89 static_assert(__builtin_strncmp("abaa", "abba", 1) == 0); 90 static_assert(__builtin_strncmp("abaa", "abba", 0) == 0); 91 static_assert(__builtin_strncmp(0, 0, 0) == 0); 92 static_assert(__builtin_strncmp("abab\0banana", "abab\0canada", 100) == 0); 93 94 static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar, 6) == -1); 95 static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar, 7) == -1); // FIXME: Should we reject this? 96 static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar + 6, 6) == 0); 97 static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar + 6, 7) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 98 99 static_assert(__builtin_memcmp("abaa", "abba", 3) == -1); 100 static_assert(__builtin_memcmp("abaa", "abba", 2) == 0); 101 static_assert(__builtin_memcmp("a\203", "a", 2) == 1); 102 static_assert(__builtin_memcmp("a\203", "a\003", 2) == 1); 103 static_assert(__builtin_memcmp(0, 0, 0) == 0); 104 static_assert(__builtin_memcmp("abab\0banana", "abab\0banana", 100) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 105 static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 100) == -1); // FIXME: Should we reject this? 106 static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 7) == -1); 107 static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 6) == -1); 108 static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 5) == 0); 109 110 static_assert(__builtin_bcmp("abaa", "abba", 3) != 0); 111 static_assert(__builtin_bcmp("abaa", "abba", 2) == 0); 112 static_assert(__builtin_bcmp("a\203", "a", 2) != 0); 113 static_assert(__builtin_bcmp("a\203", "a\003", 2) != 0); 114 static_assert(__builtin_bcmp(0, 0, 0) == 0); 115 static_assert(__builtin_bcmp("abab\0banana", "abab\0banana", 100) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 116 static_assert(__builtin_bcmp("abab\0banana", "abab\0canada", 100) != 0); // FIXME: Should we reject this? 117 static_assert(__builtin_bcmp("abab\0banana", "abab\0canada", 7) != 0); 118 static_assert(__builtin_bcmp("abab\0banana", "abab\0canada", 6) != 0); 119 static_assert(__builtin_bcmp("abab\0banana", "abab\0canada", 5) == 0); 120 121 extern struct Incomplete incomplete; 122 static_assert(__builtin_memcmp(&incomplete, "", 0u) == 0); 123 static_assert(__builtin_memcmp("", &incomplete, 0u) == 0); 124 static_assert(__builtin_memcmp(&incomplete, "", 1u) == 42); // expected-error {{not an integral constant}} expected-note {{read of incomplete type 'struct Incomplete'}} 125 static_assert(__builtin_memcmp("", &incomplete, 1u) == 42); // expected-error {{not an integral constant}} expected-note {{read of incomplete type 'struct Incomplete'}} 126 127 static_assert(__builtin_bcmp(&incomplete, "", 0u) == 0); 128 static_assert(__builtin_bcmp("", &incomplete, 0u) == 0); 129 static_assert(__builtin_bcmp(&incomplete, "", 1u) == 42); // expected-error {{not an integral constant}} expected-note {{read of incomplete type 'struct Incomplete'}} 130 static_assert(__builtin_bcmp("", &incomplete, 1u) == 42); // expected-error {{not an integral constant}} expected-note {{read of incomplete type 'struct Incomplete'}} 131 132 constexpr unsigned char ku00fe00[] = {0x00, 0xfe, 0x00}; 133 constexpr unsigned char ku00feff[] = {0x00, 0xfe, 0xff}; 134 constexpr signed char ks00fe00[] = {0, -2, 0}; 135 constexpr signed char ks00feff[] = {0, -2, -1}; 136 static_assert(__builtin_memcmp(ku00feff, ks00fe00, 2) == 0); 137 static_assert(__builtin_memcmp(ku00feff, ks00fe00, 99) == 1); 138 static_assert(__builtin_memcmp(ku00fe00, ks00feff, 99) == -1); 139 static_assert(__builtin_memcmp(ks00feff, ku00fe00, 2) == 0); 140 static_assert(__builtin_memcmp(ks00feff, ku00fe00, 99) == 1); 141 static_assert(__builtin_memcmp(ks00fe00, ku00feff, 99) == -1); 142 static_assert(__builtin_memcmp(ks00fe00, ks00feff, 2) == 0); 143 static_assert(__builtin_memcmp(ks00feff, ks00fe00, 99) == 1); 144 static_assert(__builtin_memcmp(ks00fe00, ks00feff, 99) == -1); 145 146 static_assert(__builtin_bcmp(ku00feff, ks00fe00, 2) == 0); 147 static_assert(__builtin_bcmp(ku00feff, ks00fe00, 99) != 0); 148 static_assert(__builtin_bcmp(ku00fe00, ks00feff, 99) != 0); 149 static_assert(__builtin_bcmp(ks00feff, ku00fe00, 2) == 0); 150 static_assert(__builtin_bcmp(ks00feff, ku00fe00, 99) != 0); 151 static_assert(__builtin_bcmp(ks00fe00, ku00feff, 99) != 0); 152 static_assert(__builtin_bcmp(ks00fe00, ks00feff, 2) == 0); 153 static_assert(__builtin_bcmp(ks00feff, ks00fe00, 99) != 0); 154 static_assert(__builtin_bcmp(ks00fe00, ks00feff, 99) != 0); 155 156 struct Bool3Tuple { bool bb[3]; }; 157 constexpr Bool3Tuple kb000100 = {{false, true, false}}; 158 static_assert(sizeof(bool) != 1u || __builtin_memcmp(ks00fe00, kb000100.bb, 1) == 0); 159 static_assert(sizeof(bool) != 1u || __builtin_memcmp(ks00fe00, kb000100.bb, 2) == 1); 160 161 static_assert(sizeof(bool) != 1u || __builtin_bcmp(ks00fe00, kb000100.bb, 1) == 0); 162 static_assert(sizeof(bool) != 1u || __builtin_bcmp(ks00fe00, kb000100.bb, 2) != 0); 163 164 constexpr long ksl[] = {0, -1}; 165 constexpr unsigned int kui[] = {0, 0u - 1}; 166 constexpr unsigned long long kull[] = {0, 0ull - 1}; 167 constexpr const auto *kuSizeofLong(void) { 168 if constexpr(sizeof(long) == sizeof(int)) { 169 return kui; 170 } else if constexpr(sizeof(long) == sizeof(long long)) { 171 return kull; 172 } else { 173 return nullptr; 174 } 175 } 176 static_assert(__builtin_memcmp(ksl, kuSizeofLong(), sizeof(long) - 1) == 0); 177 static_assert(__builtin_memcmp(ksl, kuSizeofLong(), sizeof(long) + 0) == 0); 178 static_assert(__builtin_memcmp(ksl, kuSizeofLong(), sizeof(long) + 1) == 0); 179 static_assert(__builtin_memcmp(ksl, kuSizeofLong(), 2*sizeof(long) - 1) == 0); 180 static_assert(__builtin_memcmp(ksl, kuSizeofLong(), 2*sizeof(long) + 0) == 0); 181 static_assert(__builtin_memcmp(ksl, kuSizeofLong(), 2*sizeof(long) + 1) == 42); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 182 static_assert(__builtin_memcmp(ksl + 1, kuSizeofLong() + 1, sizeof(long) - 1) == 0); 183 static_assert(__builtin_memcmp(ksl + 1, kuSizeofLong() + 1, sizeof(long) + 0) == 0); 184 static_assert(__builtin_memcmp(ksl + 1, kuSizeofLong() + 1, sizeof(long) + 1) == 42); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 185 186 static_assert(__builtin_bcmp(ksl, kuSizeofLong(), sizeof(long) - 1) == 0); 187 static_assert(__builtin_bcmp(ksl, kuSizeofLong(), sizeof(long) + 0) == 0); 188 static_assert(__builtin_bcmp(ksl, kuSizeofLong(), sizeof(long) + 1) == 0); 189 static_assert(__builtin_bcmp(ksl, kuSizeofLong(), 2*sizeof(long) - 1) == 0); 190 static_assert(__builtin_bcmp(ksl, kuSizeofLong(), 2*sizeof(long) + 0) == 0); 191 static_assert(__builtin_bcmp(ksl, kuSizeofLong(), 2*sizeof(long) + 1) == 42); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 192 static_assert(__builtin_bcmp(ksl + 1, kuSizeofLong() + 1, sizeof(long) - 1) == 0); 193 static_assert(__builtin_bcmp(ksl + 1, kuSizeofLong() + 1, sizeof(long) + 0) == 0); 194 static_assert(__builtin_bcmp(ksl + 1, kuSizeofLong() + 1, sizeof(long) + 1) == 42); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 195 196 constexpr int a = strcmp("hello", "world"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strcmp' cannot be used in a constant expression}} 197 constexpr int b = strncmp("hello", "world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strncmp' cannot be used in a constant expression}} 198 constexpr int c = memcmp("hello", "world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'memcmp' cannot be used in a constant expression}} 199 200 #ifdef GNUMODE 201 constexpr int d = bcmp("hello", "world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'bcmp' cannot be used in a constant expression}} 202 #endif 203 } 204 205 namespace MultibyteElementTests { 206 inline namespace Util { 207 #define STR2(X) #X 208 #define STR(X) STR2(X) 209 constexpr const char ByteOrderString[] = STR(__BYTE_ORDER__); 210 #undef STR 211 #undef STR2 212 constexpr bool LittleEndian{*ByteOrderString == '1'}; 213 214 constexpr size_t GoodFoldArraySize = 42, BadFoldArraySize = 43; 215 struct NotBadFoldResult {}; 216 template <size_t> struct FoldResult; 217 template <> struct FoldResult<GoodFoldArraySize> : NotBadFoldResult {}; 218 template <typename T, size_t N> 219 FoldResult<N> *foldResultImpl(T (*ptrToConstantSizeArray)[N]); 220 struct NotFolded : NotBadFoldResult {}; 221 NotFolded *foldResultImpl(bool anyPtr); 222 template <auto Value> struct MetaValue; 223 template <typename Callable, size_t N, auto ExpectedFoldResult> 224 auto foldResult(const Callable &, MetaValue<N> *, 225 MetaValue<ExpectedFoldResult> *) { 226 int (*maybeVLAPtr)[Callable{}(N) == ExpectedFoldResult 227 ? GoodFoldArraySize 228 : BadFoldArraySize] = 0; 229 return foldResultImpl(maybeVLAPtr); 230 } 231 template <typename FoldResultKind, typename Callable, typename NWrap, 232 typename ExpectedWrap> 233 constexpr bool checkFoldResult(const Callable &c, NWrap *n, ExpectedWrap *e) { 234 decltype(static_cast<FoldResultKind *>(foldResult(c, n, e))) *chk{}; 235 return true; 236 } 237 template <size_t N> constexpr MetaValue<N> *withN() { return nullptr; } 238 template <auto Expected> constexpr MetaValue<Expected> *withExpected() { 239 return nullptr; 240 } 241 } // namespace Util 242 } // namespace MultibyteElementTests 243 244 namespace MultibyteElementTests::Memcmp { 245 #ifdef __SIZEOF_INT128__ 246 constexpr __int128 i128_ff_8_00_8 = -(__int128)1 - -1ull; 247 constexpr __int128 i128_00_16 = 0; 248 static_assert(checkFoldResult<NotBadFoldResult>( 249 [](size_t n) constexpr { 250 return __builtin_memcmp(&i128_ff_8_00_8, &i128_00_16, n); 251 }, 252 withN<1u>(), withExpected<LittleEndian ? 0 : 1>())); 253 #endif 254 255 constexpr const signed char ByteOrderStringReduced[] = { 256 ByteOrderString[0] - '0', ByteOrderString[1] - '0', 257 ByteOrderString[2] - '0', ByteOrderString[3] - '0', 258 }; 259 constexpr signed int i04030201 = 0x04030201; 260 constexpr unsigned int u04030201 = 0x04030201u; 261 static_assert(checkFoldResult<NotBadFoldResult>( 262 [](size_t n) constexpr { 263 return __builtin_memcmp(ByteOrderStringReduced, &i04030201, n); 264 }, 265 withN<sizeof(int)>(), withExpected<0>())); 266 static_assert(checkFoldResult<NotBadFoldResult>( 267 [](size_t n) constexpr { 268 return __builtin_memcmp(&u04030201, ByteOrderStringReduced, n); 269 }, 270 withN<sizeof(int)>(), withExpected<0>())); 271 272 constexpr unsigned int ui0000FEFF = 0x0000feffU; 273 constexpr unsigned short usFEFF = 0xfeffU; 274 static_assert(checkFoldResult<NotBadFoldResult>( 275 [](size_t n) constexpr { 276 return __builtin_memcmp(&ui0000FEFF, &usFEFF, n); 277 }, 278 withN<1u>(), withExpected<LittleEndian ? 0 : -1>())); 279 280 constexpr unsigned int ui08038700 = 0x08038700u; 281 constexpr unsigned int ui08048600 = 0x08048600u; 282 static_assert(checkFoldResult<NotBadFoldResult>( 283 [](size_t n) constexpr { 284 return __builtin_memcmp(&ui08038700, &ui08048600, n); 285 }, 286 withN<sizeof(int)>(), withExpected<LittleEndian ? 1 : -1>())); 287 } 288 289 namespace WcscmpEtc { 290 constexpr wchar_t kFoobar[6] = {L'f',L'o',L'o',L'b',L'a',L'r'}; 291 constexpr wchar_t kFoobazfoobar[12] = {L'f',L'o',L'o',L'b',L'a',L'z',L'f',L'o',L'o',L'b',L'a',L'r'}; 292 293 static_assert(__builtin_wcscmp(L"abab", L"abab") == 0); 294 static_assert(__builtin_wcscmp(L"abab", L"abba") == -1); 295 static_assert(__builtin_wcscmp(L"abab", L"abaa") == 1); 296 static_assert(__builtin_wcscmp(L"ababa", L"abab") == 1); 297 static_assert(__builtin_wcscmp(L"abab", L"ababa") == -1); 298 static_assert(__builtin_wcscmp(L"abab\0banana", L"abab") == 0); 299 static_assert(__builtin_wcscmp(L"abab", L"abab\0banana") == 0); 300 static_assert(__builtin_wcscmp(L"abab\0banana", L"abab\0canada") == 0); 301 #if __WCHAR_WIDTH__ == 32 302 static_assert(__builtin_wcscmp(L"a\x83838383", L"a") == (wchar_t)-1U >> 31); 303 #endif 304 static_assert(__builtin_wcscmp(0, L"abab") == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 305 static_assert(__builtin_wcscmp(L"abab", 0) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 306 307 static_assert(__builtin_wcscmp(kFoobar, kFoobazfoobar) == -1); // FIXME: Should we reject this? 308 static_assert(__builtin_wcscmp(kFoobar, kFoobazfoobar + 6) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 309 310 static_assert(__builtin_wcsncmp(L"abaa", L"abba", 5) == -1); 311 static_assert(__builtin_wcsncmp(L"abaa", L"abba", 4) == -1); 312 static_assert(__builtin_wcsncmp(L"abaa", L"abba", 3) == -1); 313 static_assert(__builtin_wcsncmp(L"abaa", L"abba", 2) == 0); 314 static_assert(__builtin_wcsncmp(L"abaa", L"abba", 1) == 0); 315 static_assert(__builtin_wcsncmp(L"abaa", L"abba", 0) == 0); 316 static_assert(__builtin_wcsncmp(0, 0, 0) == 0); 317 static_assert(__builtin_wcsncmp(L"abab\0banana", L"abab\0canada", 100) == 0); 318 #if __WCHAR_WIDTH__ == 32 319 static_assert(__builtin_wcsncmp(L"a\x83838383", L"aa", 2) == 320 (wchar_t)-1U >> 31); 321 #endif 322 323 static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar, 6) == -1); 324 static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar, 7) == -1); // FIXME: Should we reject this? 325 static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar + 6, 6) == 0); 326 static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar + 6, 7) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 327 328 static_assert(__builtin_wmemcmp(L"abaa", L"abba", 3) == -1); 329 static_assert(__builtin_wmemcmp(L"abaa", L"abba", 2) == 0); 330 static_assert(__builtin_wmemcmp(0, 0, 0) == 0); 331 #if __WCHAR_WIDTH__ == 32 332 static_assert(__builtin_wmemcmp(L"a\x83838383", L"aa", 2) == 333 (wchar_t)-1U >> 31); 334 #endif 335 static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0banana", 100) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 336 static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 100) == -1); // FIXME: Should we reject this? 337 static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 7) == -1); 338 static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 6) == -1); 339 static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 5) == 0); 340 341 constexpr int a = wcscmp(L"hello", L"world"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wcscmp' cannot be used in a constant expression}} 342 constexpr int b = wcsncmp(L"hello", L"world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wcsncmp' cannot be used in a constant expression}} 343 constexpr int c = wmemcmp(L"hello", L"world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wmemcmp' cannot be used in a constant expression}} 344 } 345 346 namespace StrchrEtc { 347 constexpr const char *kStr = "abca\xff\0d"; 348 constexpr char kFoo[] = {'f', 'o', 'o'}; 349 static_assert(__builtin_strchr(kStr, 'a') == kStr); 350 static_assert(__builtin_strchr(kStr, 'b') == kStr + 1); 351 static_assert(__builtin_strchr(kStr, 'c') == kStr + 2); 352 static_assert(__builtin_strchr(kStr, 'd') == nullptr); 353 static_assert(__builtin_strchr(kStr, 'e') == nullptr); 354 static_assert(__builtin_strchr(kStr, '\0') == kStr + 5); 355 static_assert(__builtin_strchr(kStr, 'a' + 256) == nullptr); 356 static_assert(__builtin_strchr(kStr, 'a' - 256) == nullptr); 357 static_assert(__builtin_strchr(kStr, '\xff') == kStr + 4); 358 static_assert(__builtin_strchr(kStr, '\xff' + 256) == nullptr); 359 static_assert(__builtin_strchr(kStr, '\xff' - 256) == nullptr); 360 static_assert(__builtin_strchr(kFoo, 'o') == kFoo + 1); 361 static_assert(__builtin_strchr(kFoo, 'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 362 static_assert(__builtin_strchr(nullptr, 'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 363 364 static_assert(__builtin_memchr(kStr, 'a', 0) == nullptr); 365 static_assert(__builtin_memchr(kStr, 'a', 1) == kStr); 366 static_assert(__builtin_memchr(kStr, '\0', 5) == nullptr); 367 static_assert(__builtin_memchr(kStr, '\0', 6) == kStr + 5); 368 static_assert(__builtin_memchr(kStr, '\xff', 8) == kStr + 4); 369 static_assert(__builtin_memchr(kStr, '\xff' + 256, 8) == kStr + 4); 370 static_assert(__builtin_memchr(kStr, '\xff' - 256, 8) == kStr + 4); 371 static_assert(__builtin_memchr(kFoo, 'x', 3) == nullptr); 372 static_assert(__builtin_memchr(kFoo, 'x', 4) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 373 static_assert(__builtin_memchr(nullptr, 'x', 3) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 374 static_assert(__builtin_memchr(nullptr, 'x', 0) == nullptr); // FIXME: Should we reject this? 375 376 extern struct Incomplete incomplete; 377 static_assert(__builtin_memchr(&incomplete, 0, 0u) == nullptr); 378 static_assert(__builtin_memchr(&incomplete, 0, 1u) == nullptr); // expected-error {{not an integral constant}} expected-note {{read of incomplete type 'struct Incomplete'}} 379 380 const unsigned char &u1 = 0xf0; 381 auto &&i1 = (const signed char []){-128}; // expected-warning {{compound literals are a C99-specific feature}} 382 static_assert(__builtin_memchr(&u1, -(0x0f + 1), 1) == &u1); 383 static_assert(__builtin_memchr(i1, 0x80, 1) == i1); 384 385 enum class E : unsigned char {}; 386 struct EPair { E e, f; }; 387 constexpr EPair ee{E{240}}; 388 static_assert(__builtin_memchr(&ee.e, 240, 1) == &ee.e); 389 390 constexpr bool kBool[] = {false, true, false}; 391 constexpr const bool *const kBoolPastTheEndPtr = kBool + 3; 392 static_assert(sizeof(bool) != 1u || __builtin_memchr(kBoolPastTheEndPtr - 3, 1, 99) == kBool + 1); 393 static_assert(sizeof(bool) != 1u || __builtin_memchr(kBool + 1, 0, 99) == kBoolPastTheEndPtr - 1); 394 static_assert(sizeof(bool) != 1u || __builtin_memchr(kBoolPastTheEndPtr - 3, -1, 3) == nullptr); 395 static_assert(sizeof(bool) != 1u || __builtin_memchr(kBoolPastTheEndPtr, 0, 1) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 396 397 static_assert(__builtin_char_memchr(kStr, 'a', 0) == nullptr); 398 static_assert(__builtin_char_memchr(kStr, 'a', 1) == kStr); 399 static_assert(__builtin_char_memchr(kStr, '\0', 5) == nullptr); 400 static_assert(__builtin_char_memchr(kStr, '\0', 6) == kStr + 5); 401 static_assert(__builtin_char_memchr(kStr, '\xff', 8) == kStr + 4); 402 static_assert(__builtin_char_memchr(kStr, '\xff' + 256, 8) == kStr + 4); 403 static_assert(__builtin_char_memchr(kStr, '\xff' - 256, 8) == kStr + 4); 404 static_assert(__builtin_char_memchr(kFoo, 'x', 3) == nullptr); 405 static_assert(__builtin_char_memchr(kFoo, 'x', 4) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 406 static_assert(__builtin_char_memchr(nullptr, 'x', 3) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 407 static_assert(__builtin_char_memchr(nullptr, 'x', 0) == nullptr); // FIXME: Should we reject this? 408 409 static_assert(*__builtin_char_memchr(kStr, '\xff', 8) == '\xff'); 410 constexpr bool char_memchr_mutable() { 411 char buffer[] = "mutable"; 412 *__builtin_char_memchr(buffer, 't', 8) = 'r'; 413 *__builtin_char_memchr(buffer, 'm', 8) = 'd'; 414 return __builtin_strcmp(buffer, "durable") == 0; 415 } 416 static_assert(char_memchr_mutable()); 417 418 constexpr bool a = !strchr("hello", 'h'); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strchr' cannot be used in a constant expression}} 419 constexpr bool b = !memchr("hello", 'h', 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'memchr' cannot be used in a constant expression}} 420 } 421 422 namespace MultibyteElementTests::Memchr { 423 constexpr unsigned int u04030201 = 0x04030201; 424 static_assert(checkFoldResult<NotBadFoldResult>( 425 [](size_t n) constexpr { 426 return __builtin_memchr(&u04030201, *ByteOrderString - '0', n); 427 }, 428 withN<1u>(), withExpected<&u04030201>())); 429 430 constexpr unsigned int uED = 0xEDU; 431 static_assert(checkFoldResult<NotBadFoldResult>( 432 [](size_t n) constexpr { 433 return __builtin_memchr(&uED, 0xED, n); 434 }, 435 withN<1u>(), withExpected<LittleEndian ? &uED : nullptr>())); 436 } 437 438 namespace WcschrEtc { 439 constexpr const wchar_t *kStr = L"abca\xffff\0dL"; 440 constexpr wchar_t kFoo[] = {L'f', L'o', L'o'}; 441 static_assert(__builtin_wcschr(kStr, L'a') == kStr); 442 static_assert(__builtin_wcschr(kStr, L'b') == kStr + 1); 443 static_assert(__builtin_wcschr(kStr, L'c') == kStr + 2); 444 static_assert(__builtin_wcschr(kStr, L'd') == nullptr); 445 static_assert(__builtin_wcschr(kStr, L'e') == nullptr); 446 static_assert(__builtin_wcschr(kStr, L'\0') == kStr + 5); 447 static_assert(__builtin_wcschr(kStr, L'a' + 256) == nullptr); 448 static_assert(__builtin_wcschr(kStr, L'a' - 256) == nullptr); 449 static_assert(__builtin_wcschr(kStr, L'\xffff') == kStr + 4); 450 static_assert(__builtin_wcschr(kFoo, L'o') == kFoo + 1); 451 static_assert(__builtin_wcschr(kFoo, L'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 452 static_assert(__builtin_wcschr(nullptr, L'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 453 454 static_assert(__builtin_wmemchr(kStr, L'a', 0) == nullptr); 455 static_assert(__builtin_wmemchr(kStr, L'a', 1) == kStr); 456 static_assert(__builtin_wmemchr(kStr, L'\0', 5) == nullptr); 457 static_assert(__builtin_wmemchr(kStr, L'\0', 6) == kStr + 5); 458 static_assert(__builtin_wmemchr(kStr, L'\xffff', 8) == kStr + 4); 459 static_assert(__builtin_wmemchr(kFoo, L'x', 3) == nullptr); 460 static_assert(__builtin_wmemchr(kFoo, L'x', 4) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}} 461 static_assert(__builtin_wmemchr(nullptr, L'x', 3) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}} 462 static_assert(__builtin_wmemchr(nullptr, L'x', 0) == nullptr); // FIXME: Should we reject this? 463 464 constexpr bool a = !wcschr(L"hello", L'h'); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wcschr' cannot be used in a constant expression}} 465 constexpr bool b = !wmemchr(L"hello", L'h', 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wmemchr' cannot be used in a constant expression}} 466 } 467 468 namespace MemcpyEtc { 469 template<typename T> 470 constexpr T result(T (&arr)[4]) { 471 return arr[0] * 1000 + arr[1] * 100 + arr[2] * 10 + arr[3]; 472 } 473 474 constexpr int test_memcpy(int a, int b, int n) { 475 int arr[4] = {1, 2, 3, 4}; 476 __builtin_memcpy(arr + a, arr + b, n); 477 // expected-note@-1 2{{overlapping memory regions}} 478 // expected-note@-2 {{size to copy (1) is not a multiple of size of element type 'int'}} 479 // expected-note@-3 {{source is not a contiguous array of at least 2 elements of type 'int'}} 480 // expected-note@-4 {{destination is not a contiguous array of at least 3 elements of type 'int'}} 481 return result(arr); 482 } 483 constexpr int test_memmove(int a, int b, int n) { 484 int arr[4] = {1, 2, 3, 4}; 485 __builtin_memmove(arr + a, arr + b, n); 486 // expected-note@-1 {{size to copy (1) is not a multiple of size of element type 'int'}} 487 // expected-note@-2 {{source is not a contiguous array of at least 2 elements of type 'int'}} 488 // expected-note@-3 {{destination is not a contiguous array of at least 3 elements of type 'int'}} 489 return result(arr); 490 } 491 constexpr int test_wmemcpy(int a, int b, int n) { 492 wchar_t arr[4] = {1, 2, 3, 4}; 493 __builtin_wmemcpy(arr + a, arr + b, n); 494 // expected-note@-1 2{{overlapping memory regions}} 495 // expected-note@-2 {{source is not a contiguous array of at least 2 elements of type 'wchar_t'}} 496 // expected-note@-3 {{destination is not a contiguous array of at least 3 elements of type 'wchar_t'}} 497 return result(arr); 498 } 499 constexpr int test_wmemmove(int a, int b, int n) { 500 wchar_t arr[4] = {1, 2, 3, 4}; 501 __builtin_wmemmove(arr + a, arr + b, n); 502 // expected-note@-1 {{source is not a contiguous array of at least 2 elements of type 'wchar_t'}} 503 // expected-note@-2 {{destination is not a contiguous array of at least 3 elements of type 'wchar_t'}} 504 return result(arr); 505 } 506 507 static_assert(test_memcpy(1, 2, 4) == 1334); 508 static_assert(test_memcpy(2, 1, 4) == 1224); 509 static_assert(test_memcpy(0, 1, 8) == 2334); // expected-error {{constant}} expected-note {{in call}} 510 static_assert(test_memcpy(1, 0, 8) == 1124); // expected-error {{constant}} expected-note {{in call}} 511 static_assert(test_memcpy(1, 2, 1) == 1334); // expected-error {{constant}} expected-note {{in call}} 512 static_assert(test_memcpy(0, 3, 4) == 4234); 513 static_assert(test_memcpy(0, 3, 8) == 4234); // expected-error {{constant}} expected-note {{in call}} 514 static_assert(test_memcpy(2, 0, 12) == 4234); // expected-error {{constant}} expected-note {{in call}} 515 516 static_assert(test_memmove(1, 2, 4) == 1334); 517 static_assert(test_memmove(2, 1, 4) == 1224); 518 static_assert(test_memmove(0, 1, 8) == 2334); 519 static_assert(test_memmove(1, 0, 8) == 1124); 520 static_assert(test_memmove(1, 2, 1) == 1334); // expected-error {{constant}} expected-note {{in call}} 521 static_assert(test_memmove(0, 3, 4) == 4234); 522 static_assert(test_memmove(0, 3, 8) == 4234); // expected-error {{constant}} expected-note {{in call}} 523 static_assert(test_memmove(2, 0, 12) == 4234); // expected-error {{constant}} expected-note {{in call}} 524 525 static_assert(test_wmemcpy(1, 2, 1) == 1334); 526 static_assert(test_wmemcpy(2, 1, 1) == 1224); 527 static_assert(test_wmemcpy(0, 1, 2) == 2334); // expected-error {{constant}} expected-note {{in call}} 528 static_assert(test_wmemcpy(1, 0, 2) == 1124); // expected-error {{constant}} expected-note {{in call}} 529 static_assert(test_wmemcpy(1, 2, 1) == 1334); 530 static_assert(test_wmemcpy(0, 3, 1) == 4234); 531 static_assert(test_wmemcpy(0, 3, 2) == 4234); // expected-error {{constant}} expected-note {{in call}} 532 static_assert(test_wmemcpy(2, 0, 3) == 4234); // expected-error {{constant}} expected-note {{in call}} 533 534 static_assert(test_wmemmove(1, 2, 1) == 1334); 535 static_assert(test_wmemmove(2, 1, 1) == 1224); 536 static_assert(test_wmemmove(0, 1, 2) == 2334); 537 static_assert(test_wmemmove(1, 0, 2) == 1124); 538 static_assert(test_wmemmove(1, 2, 1) == 1334); 539 static_assert(test_wmemmove(0, 3, 1) == 4234); 540 static_assert(test_wmemmove(0, 3, 2) == 4234); // expected-error {{constant}} expected-note {{in call}} 541 static_assert(test_wmemmove(2, 0, 3) == 4234); // expected-error {{constant}} expected-note {{in call}} 542 543 #define fold(x) (__builtin_constant_p(0) ? (x) : (x)) 544 545 wchar_t global; 546 constexpr wchar_t *null = 0; 547 static_assert(__builtin_memcpy(&global, null, sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'memcpy' is nullptr}} 548 static_assert(__builtin_memmove(&global, null, sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'memmove' is nullptr}} 549 static_assert(__builtin_wmemcpy(&global, null, sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'wmemcpy' is nullptr}} 550 static_assert(__builtin_wmemmove(&global, null, sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'wmemmove' is nullptr}} 551 static_assert(__builtin_memcpy(null, &global, sizeof(wchar_t))); // expected-error {{}} expected-note {{destination of 'memcpy' is nullptr}} 552 static_assert(__builtin_memmove(null, &global, sizeof(wchar_t))); // expected-error {{}} expected-note {{destination of 'memmove' is nullptr}} 553 static_assert(__builtin_wmemcpy(null, &global, sizeof(wchar_t))); // expected-error {{}} expected-note {{destination of 'wmemcpy' is nullptr}} 554 static_assert(__builtin_wmemmove(null, &global, sizeof(wchar_t))); // expected-error {{}} expected-note {{destination of 'wmemmove' is nullptr}} 555 static_assert(__builtin_memcpy(&global, fold((wchar_t*)123), sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'memcpy' is (void *)123}} 556 static_assert(__builtin_memcpy(fold(reinterpret_cast<wchar_t*>(123)), &global, sizeof(wchar_t))); // expected-error {{}} expected-note {{destination of 'memcpy' is (void *)123}} 557 constexpr struct Incomplete *null_incomplete = 0; 558 static_assert(__builtin_memcpy(null_incomplete, null_incomplete, sizeof(wchar_t))); // expected-error {{}} expected-note {{source of 'memcpy' is nullptr}} 559 560 // Copying is permitted for any trivially-copyable type. 561 struct Trivial { char k; short s; constexpr bool ok() { return k == 3 && s == 4; } }; 562 constexpr bool test_trivial() { 563 Trivial arr[3] = {{1, 2}, {3, 4}, {5, 6}}; 564 __builtin_memcpy(arr, arr+1, sizeof(Trivial)); 565 __builtin_memmove(arr+1, arr, 2 * sizeof(Trivial)); 566 return arr[0].ok() && arr[1].ok() && arr[2].ok(); 567 } 568 static_assert(test_trivial()); 569 570 // But not for a non-trivially-copyable type. 571 struct NonTrivial { 572 constexpr NonTrivial() : n(0) {} 573 constexpr NonTrivial(const NonTrivial &) : n(1) {} 574 int n; 575 }; 576 constexpr bool test_nontrivial_memcpy() { // expected-error {{never produces a constant}} 577 NonTrivial arr[3] = {}; 578 __builtin_memcpy(arr, arr + 1, sizeof(NonTrivial)); // expected-note 2{{non-trivially-copyable}} 579 return true; 580 } 581 static_assert(test_nontrivial_memcpy()); // expected-error {{constant}} expected-note {{in call}} 582 constexpr bool test_nontrivial_memmove() { // expected-error {{never produces a constant}} 583 NonTrivial arr[3] = {}; 584 __builtin_memcpy(arr, arr + 1, sizeof(NonTrivial)); // expected-note 2{{non-trivially-copyable}} 585 return true; 586 } 587 static_assert(test_nontrivial_memmove()); // expected-error {{constant}} expected-note {{in call}} 588 589 // Type puns via constant evaluated memcpy are not supported yet. 590 constexpr float type_pun(const unsigned &n) { 591 float f = 0.0f; 592 __builtin_memcpy(&f, &n, 4); // expected-note {{cannot constant evaluate 'memcpy' from object of type 'const unsigned int' to object of type 'float'}} 593 return f; 594 } 595 static_assert(type_pun(0x3f800000) == 1.0f); // expected-error {{constant}} expected-note {{in call}} 596 597 // Make sure we're not confused by derived-to-base conversions. 598 struct Base { int a; }; 599 struct Derived : Base { int b; }; 600 constexpr int test_derived_to_base(int n) { 601 Derived arr[2] = {1, 2, 3, 4}; 602 Base *p = &arr[0]; 603 Base *q = &arr[1]; 604 __builtin_memcpy(p, q, sizeof(Base) * n); // expected-note {{source is not a contiguous array of at least 2 elements of type 'MemcpyEtc::Base'}} 605 return arr[0].a * 1000 + arr[0].b * 100 + arr[1].a * 10 + arr[1].b; 606 } 607 static_assert(test_derived_to_base(0) == 1234); 608 static_assert(test_derived_to_base(1) == 3234); 609 // FIXME: We could consider making this work by stripping elements off both 610 // designators until we have a long enough matching size, if both designators 611 // point to the start of their respective final elements. 612 static_assert(test_derived_to_base(2) == 3434); // expected-error {{constant}} expected-note {{in call}} 613 614 // Check that when address-of an array is passed to a tested function the 615 // array can be fully copied. 616 constexpr int test_address_of_const_array_type() { 617 int arr[4] = {1, 2, 3, 4}; 618 __builtin_memmove(&arr, &arr, sizeof(arr)); 619 return arr[0] * 1000 + arr[1] * 100 + arr[2] * 10 + arr[3]; 620 } 621 static_assert(test_address_of_const_array_type() == 1234); 622 623 // Check that an incomplete array is rejected. 624 constexpr int test_incomplete_array_type() { // expected-error {{never produces a constant}} 625 extern int arr[]; 626 __builtin_memmove(arr, arr, 4 * sizeof(arr[0])); 627 // expected-note@-1 2{{'memmove' not supported: source is not a contiguous array of at least 4 elements of type 'int'}} 628 return arr[0] * 1000 + arr[1] * 100 + arr[2] * 10 + arr[3]; 629 } 630 static_assert(test_incomplete_array_type() == 1234); // expected-error {{constant}} expected-note {{in call}} 631 632 // Check that a pointer to an incomplete array is rejected. 633 constexpr int test_address_of_incomplete_array_type() { // expected-error {{never produces a constant}} 634 extern int arr[]; 635 __builtin_memmove(&arr, &arr, 4 * sizeof(arr[0])); 636 // expected-note@-1 2{{cannot constant evaluate 'memmove' between objects of incomplete type 'int []'}} 637 return arr[0] * 1000 + arr[1] * 100 + arr[2] * 10 + arr[3]; 638 } 639 static_assert(test_address_of_incomplete_array_type() == 1234); // expected-error {{constant}} expected-note {{in call}} 640 641 // Check that a pointer to an incomplete struct is rejected. 642 constexpr bool test_address_of_incomplete_struct_type() { // expected-error {{never produces a constant}} 643 struct Incomplete; 644 extern Incomplete x, y; 645 __builtin_memcpy(&x, &x, 4); 646 // expected-note@-1 2{{cannot constant evaluate 'memcpy' between objects of incomplete type 'Incomplete'}} 647 return true; 648 } 649 static_assert(test_address_of_incomplete_struct_type()); // expected-error {{constant}} expected-note {{in call}} 650 } 651