1 // RUN: %clang_cc1 %s -std=c++1z -fsyntax-only -verify -pedantic
2 // RUN: %clang_cc1 %s -std=c++1z -fsyntax-only -verify -pedantic -fno-signed-char
3 // RUN: %clang_cc1 %s -std=c++1z -fsyntax-only -verify -pedantic -fno-wchar -Dwchar_t=__WCHAR_TYPE__
4 
5 # 6 "/usr/include/string.h" 1 3 4
6 extern "C" {
7   typedef decltype(sizeof(int)) size_t;
8 
9   extern size_t strlen(const char *p);
10 
11   extern int strcmp(const char *s1, const char *s2);
12   extern int strncmp(const char *s1, const char *s2, size_t n);
13   extern int memcmp(const void *s1, const void *s2, size_t n);
14 
15   extern char *strchr(const char *s, int c);
16   extern void *memchr(const void *s, int c, size_t n);
17 }
18 # 19 "SemaCXX/constexpr-string.cpp" 2
19 
20 # 21 "/usr/include/wchar.h" 1 3 4
21 extern "C" {
22   extern size_t wcslen(const wchar_t *p);
23 
24   extern int wcscmp(const wchar_t *s1, const wchar_t *s2);
25   extern int wcsncmp(const wchar_t *s1, const wchar_t *s2, size_t n);
26   extern int wmemcmp(const wchar_t *s1, const wchar_t *s2, size_t n);
27 
28   extern wchar_t *wcschr(const wchar_t *s, wchar_t c);
29   extern wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n);
30 }
31 
32 # 33 "SemaCXX/constexpr-string.cpp" 2
33 namespace Strlen {
34   constexpr int n = __builtin_strlen("hello"); // ok
35   static_assert(n == 5);
36   constexpr int wn = __builtin_wcslen(L"hello"); // ok
37   static_assert(wn == 5);
38   constexpr int m = strlen("hello"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strlen' cannot be used in a constant expression}}
39   constexpr int wm = wcslen(L"hello"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'wcslen' cannot be used in a constant expression}}
40 
41   // Make sure we can evaluate a call to strlen.
42   int arr[3]; // expected-note 2{{here}}
43   int k = arr[strlen("hello")]; // expected-warning {{array index 5}}
44   int wk = arr[wcslen(L"hello")]; // expected-warning {{array index 5}}
45 }
46 
47 namespace StrcmpEtc {
48   constexpr char kFoobar[6] = {'f','o','o','b','a','r'};
49   constexpr char kFoobazfoobar[12] = {'f','o','o','b','a','z','f','o','o','b','a','r'};
50 
51   static_assert(__builtin_strcmp("abab", "abab") == 0);
52   static_assert(__builtin_strcmp("abab", "abba") == -1);
53   static_assert(__builtin_strcmp("abab", "abaa") == 1);
54   static_assert(__builtin_strcmp("ababa", "abab") == 1);
55   static_assert(__builtin_strcmp("abab", "ababa") == -1);
56   static_assert(__builtin_strcmp("abab\0banana", "abab") == 0);
57   static_assert(__builtin_strcmp("abab", "abab\0banana") == 0);
58   static_assert(__builtin_strcmp("abab\0banana", "abab\0canada") == 0);
59   static_assert(__builtin_strcmp(0, "abab") == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
60   static_assert(__builtin_strcmp("abab", 0) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
61 
62   static_assert(__builtin_strcmp(kFoobar, kFoobazfoobar) == -1); // FIXME: Should we reject this?
63   static_assert(__builtin_strcmp(kFoobar, kFoobazfoobar + 6) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
64 
65   static_assert(__builtin_strncmp("abaa", "abba", 5) == -1);
66   static_assert(__builtin_strncmp("abaa", "abba", 4) == -1);
67   static_assert(__builtin_strncmp("abaa", "abba", 3) == -1);
68   static_assert(__builtin_strncmp("abaa", "abba", 2) == 0);
69   static_assert(__builtin_strncmp("abaa", "abba", 1) == 0);
70   static_assert(__builtin_strncmp("abaa", "abba", 0) == 0);
71   static_assert(__builtin_strncmp(0, 0, 0) == 0);
72   static_assert(__builtin_strncmp("abab\0banana", "abab\0canada", 100) == 0);
73 
74   static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar, 6) == -1);
75   static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar, 7) == -1); // FIXME: Should we reject this?
76   static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar + 6, 6) == 0);
77   static_assert(__builtin_strncmp(kFoobar, kFoobazfoobar + 6, 7) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
78 
79   static_assert(__builtin_memcmp("abaa", "abba", 3) == -1);
80   static_assert(__builtin_memcmp("abaa", "abba", 2) == 0);
81   static_assert(__builtin_memcmp(0, 0, 0) == 0);
82   static_assert(__builtin_memcmp("abab\0banana", "abab\0banana", 100) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
83   static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 100) == -1); // FIXME: Should we reject this?
84   static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 7) == -1);
85   static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 6) == -1);
86   static_assert(__builtin_memcmp("abab\0banana", "abab\0canada", 5) == 0);
87 
88   constexpr int a = strcmp("hello", "world"); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strcmp' cannot be used in a constant expression}}
89   constexpr int b = strncmp("hello", "world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strncmp' cannot be used in a constant expression}}
90   constexpr int c = memcmp("hello", "world", 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'memcmp' cannot be used in a constant expression}}
91 }
92 
93 namespace WcscmpEtc {
94   constexpr wchar_t kFoobar[6] = {L'f',L'o',L'o',L'b',L'a',L'r'};
95   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'};
96 
97   static_assert(__builtin_wcscmp(L"abab", L"abab") == 0);
98   static_assert(__builtin_wcscmp(L"abab", L"abba") == -1);
99   static_assert(__builtin_wcscmp(L"abab", L"abaa") == 1);
100   static_assert(__builtin_wcscmp(L"ababa", L"abab") == 1);
101   static_assert(__builtin_wcscmp(L"abab", L"ababa") == -1);
102   static_assert(__builtin_wcscmp(L"abab\0banana", L"abab") == 0);
103   static_assert(__builtin_wcscmp(L"abab", L"abab\0banana") == 0);
104   static_assert(__builtin_wcscmp(L"abab\0banana", L"abab\0canada") == 0);
105   static_assert(__builtin_wcscmp(0, L"abab") == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
106   static_assert(__builtin_wcscmp(L"abab", 0) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
107 
108   static_assert(__builtin_wcscmp(kFoobar, kFoobazfoobar) == -1); // FIXME: Should we reject this?
109   static_assert(__builtin_wcscmp(kFoobar, kFoobazfoobar + 6) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
110 
111   static_assert(__builtin_wcsncmp(L"abaa", L"abba", 5) == -1);
112   static_assert(__builtin_wcsncmp(L"abaa", L"abba", 4) == -1);
113   static_assert(__builtin_wcsncmp(L"abaa", L"abba", 3) == -1);
114   static_assert(__builtin_wcsncmp(L"abaa", L"abba", 2) == 0);
115   static_assert(__builtin_wcsncmp(L"abaa", L"abba", 1) == 0);
116   static_assert(__builtin_wcsncmp(L"abaa", L"abba", 0) == 0);
117   static_assert(__builtin_wcsncmp(0, 0, 0) == 0);
118   static_assert(__builtin_wcsncmp(L"abab\0banana", L"abab\0canada", 100) == 0);
119 
120   static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar, 6) == -1);
121   static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar, 7) == -1); // FIXME: Should we reject this?
122   static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar + 6, 6) == 0);
123   static_assert(__builtin_wcsncmp(kFoobar, kFoobazfoobar + 6, 7) == 0); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
124 
125   static_assert(__builtin_wmemcmp(L"abaa", L"abba", 3) == -1);
126   static_assert(__builtin_wmemcmp(L"abaa", L"abba", 2) == 0);
127   static_assert(__builtin_wmemcmp(0, 0, 0) == 0);
128   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}}
129   static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 100) == -1); // FIXME: Should we reject this?
130   static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 7) == -1);
131   static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 6) == -1);
132   static_assert(__builtin_wmemcmp(L"abab\0banana", L"abab\0canada", 5) == 0);
133 
134   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}}
135   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}}
136   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}}
137 }
138 
139 namespace StrchrEtc {
140   constexpr const char *kStr = "abca\xff\0d";
141   constexpr char kFoo[] = {'f', 'o', 'o'};
142   static_assert(__builtin_strchr(kStr, 'a') == kStr);
143   static_assert(__builtin_strchr(kStr, 'b') == kStr + 1);
144   static_assert(__builtin_strchr(kStr, 'c') == kStr + 2);
145   static_assert(__builtin_strchr(kStr, 'd') == nullptr);
146   static_assert(__builtin_strchr(kStr, 'e') == nullptr);
147   static_assert(__builtin_strchr(kStr, '\0') == kStr + 5);
148   static_assert(__builtin_strchr(kStr, 'a' + 256) == nullptr);
149   static_assert(__builtin_strchr(kStr, 'a' - 256) == nullptr);
150   static_assert(__builtin_strchr(kStr, '\xff') == kStr + 4);
151   static_assert(__builtin_strchr(kStr, '\xff' + 256) == nullptr);
152   static_assert(__builtin_strchr(kStr, '\xff' - 256) == nullptr);
153   static_assert(__builtin_strchr(kFoo, 'o') == kFoo + 1);
154   static_assert(__builtin_strchr(kFoo, 'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
155   static_assert(__builtin_strchr(nullptr, 'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
156 
157   static_assert(__builtin_memchr(kStr, 'a', 0) == nullptr);
158   static_assert(__builtin_memchr(kStr, 'a', 1) == kStr);
159   static_assert(__builtin_memchr(kStr, '\0', 5) == nullptr);
160   static_assert(__builtin_memchr(kStr, '\0', 6) == kStr + 5);
161   static_assert(__builtin_memchr(kStr, '\xff', 8) == kStr + 4);
162   static_assert(__builtin_memchr(kStr, '\xff' + 256, 8) == kStr + 4);
163   static_assert(__builtin_memchr(kStr, '\xff' - 256, 8) == kStr + 4);
164   static_assert(__builtin_memchr(kFoo, 'x', 3) == nullptr);
165   static_assert(__builtin_memchr(kFoo, 'x', 4) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
166   static_assert(__builtin_memchr(nullptr, 'x', 3) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
167   static_assert(__builtin_memchr(nullptr, 'x', 0) == nullptr); // FIXME: Should we reject this?
168 
169   static_assert(__builtin_char_memchr(kStr, 'a', 0) == nullptr);
170   static_assert(__builtin_char_memchr(kStr, 'a', 1) == kStr);
171   static_assert(__builtin_char_memchr(kStr, '\0', 5) == nullptr);
172   static_assert(__builtin_char_memchr(kStr, '\0', 6) == kStr + 5);
173   static_assert(__builtin_char_memchr(kStr, '\xff', 8) == kStr + 4);
174   static_assert(__builtin_char_memchr(kStr, '\xff' + 256, 8) == kStr + 4);
175   static_assert(__builtin_char_memchr(kStr, '\xff' - 256, 8) == kStr + 4);
176   static_assert(__builtin_char_memchr(kFoo, 'x', 3) == nullptr);
177   static_assert(__builtin_char_memchr(kFoo, 'x', 4) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
178   static_assert(__builtin_char_memchr(nullptr, 'x', 3) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
179   static_assert(__builtin_char_memchr(nullptr, 'x', 0) == nullptr); // FIXME: Should we reject this?
180 
181   static_assert(*__builtin_char_memchr(kStr, '\xff', 8) == '\xff');
182   constexpr bool char_memchr_mutable() {
183     char buffer[] = "mutable";
184     *__builtin_char_memchr(buffer, 't', 8) = 'r';
185     *__builtin_char_memchr(buffer, 'm', 8) = 'd';
186     return __builtin_strcmp(buffer, "durable") == 0;
187   }
188   static_assert(char_memchr_mutable());
189 
190   constexpr bool a = !strchr("hello", 'h'); // expected-error {{constant expression}} expected-note {{non-constexpr function 'strchr' cannot be used in a constant expression}}
191   constexpr bool b = !memchr("hello", 'h', 3); // expected-error {{constant expression}} expected-note {{non-constexpr function 'memchr' cannot be used in a constant expression}}
192 }
193 
194 namespace WcschrEtc {
195   constexpr const wchar_t *kStr = L"abca\xffff\0dL";
196   constexpr wchar_t kFoo[] = {L'f', L'o', L'o'};
197   static_assert(__builtin_wcschr(kStr, L'a') == kStr);
198   static_assert(__builtin_wcschr(kStr, L'b') == kStr + 1);
199   static_assert(__builtin_wcschr(kStr, L'c') == kStr + 2);
200   static_assert(__builtin_wcschr(kStr, L'd') == nullptr);
201   static_assert(__builtin_wcschr(kStr, L'e') == nullptr);
202   static_assert(__builtin_wcschr(kStr, L'\0') == kStr + 5);
203   static_assert(__builtin_wcschr(kStr, L'a' + 256) == nullptr);
204   static_assert(__builtin_wcschr(kStr, L'a' - 256) == nullptr);
205   static_assert(__builtin_wcschr(kStr, L'\xffff') == kStr + 4);
206   static_assert(__builtin_wcschr(kFoo, L'o') == kFoo + 1);
207   static_assert(__builtin_wcschr(kFoo, L'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
208   static_assert(__builtin_wcschr(nullptr, L'x') == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
209 
210   static_assert(__builtin_wmemchr(kStr, L'a', 0) == nullptr);
211   static_assert(__builtin_wmemchr(kStr, L'a', 1) == kStr);
212   static_assert(__builtin_wmemchr(kStr, L'\0', 5) == nullptr);
213   static_assert(__builtin_wmemchr(kStr, L'\0', 6) == kStr + 5);
214   static_assert(__builtin_wmemchr(kStr, L'\xffff', 8) == kStr + 4);
215   static_assert(__builtin_wmemchr(kFoo, L'x', 3) == nullptr);
216   static_assert(__builtin_wmemchr(kFoo, L'x', 4) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced one-past-the-end}}
217   static_assert(__builtin_wmemchr(nullptr, L'x', 3) == nullptr); // expected-error {{not an integral constant}} expected-note {{dereferenced null}}
218   static_assert(__builtin_wmemchr(nullptr, L'x', 0) == nullptr); // FIXME: Should we reject this?
219 
220   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}}
221   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}}
222 }
223