xref: /llvm-project/clang/test/AST/ByteCode/c23.c (revision d70f54f248853f4d5f9e71a51dfda53a47f0b7d3)
1 // RUN: %clang_cc1 -std=c23 -fexperimental-new-constant-interpreter -verify=expected,both %s
2 // RUN: %clang_cc1 -std=c23 -verify=ref,both %s
3 // RUN: %clang_cc1 -std=c23 -triple=aarch64_be-linux-gnu -fexperimental-new-constant-interpreter -verify=expected,both %s
4 // RUN: %clang_cc1 -std=c23 -triple=aarch64_be-linux-gnu -verify=ref,both %s
5 
6 
7 typedef typeof(nullptr) nullptr_t;
8 
9 const _Bool inf1 =  (1.0/0.0 == __builtin_inf());
10 constexpr _Bool inf2 = (1.0/0.0 == __builtin_inf()); // both-error {{must be initialized by a constant expression}} \
11                                                      // both-note {{division by zero}}
12 constexpr _Bool inf3 = __builtin_inf() == __builtin_inf();
13 
14 /// Used to crash.
15 struct S {
16   int x;
17   char c;
18   float f;
19 };
20 
21 #define DECL_BUFFER(Ty, Name) alignas(Ty) unsigned char Name[sizeof(Ty)]
22 
23 char bar() {
24   DECL_BUFFER(struct S, buffer);
25   ((struct S *)buffer)->c = 'a';
26   return ((struct S *)buffer)->c;
27 }
28 
29 static_assert((nullptr_t){} == 0);
30 
31 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
32 #  define LITTLE_END 1
33 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
34 #  define LITTLE_END 0
35 #else
36 #  error "huh?"
37 #endif
38 
39 typedef unsigned char u8x4_t __attribute__((vector_size(4)));
40 constexpr u8x4_t arg1 = (u8x4_t)0xCAFEBABE; // okay
41 #if LITTLE_END
42 static_assert(arg1[0] == 190);
43 static_assert(arg1[1] == 186);
44 static_assert(arg1[2] == 254);
45 static_assert(arg1[3] == 202);
46 #else
47 static_assert(arg1[0] == 202);
48 static_assert(arg1[1] == 254);
49 static_assert(arg1[2] == 186);
50 static_assert(arg1[3] == 190);
51 #endif
52 
53 void ghissue109095() {
54   constexpr char c[] = { 'a' };
55   constexpr int i = c[1]; // both-error {{constexpr variable 'i' must be initialized by a constant expression}}\
56                           // both-note {{declared here}}
57   _Static_assert(i == c[0]); // both-error {{static assertion expression is not an integral constant expression}}\
58                              // both-note {{initializer of 'i' is not a constant expression}}
59 }
60