1 // RUN: %clang_cc1 -fsyntax-only -verify=expected,c23 -std=c23 %s
2 // RUN: %clang_cc1 -fsyntax-only -verify=expected,c17 -std=c17 %s
3
4 #define AUTO_MACRO(_NAME, ARG, ARG2, ARG3) \
5 auto _NAME = ARG + (ARG2 / ARG3);
6
7 struct S {
8 int a;
9 auto b; // c23-error {{'auto' not allowed in struct member}} \
10 c17-error {{type name does not allow storage class to be specified}} \
11 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
12 union {
13 char c;
14 auto smth; // c23-error {{'auto' not allowed in union member}} \
15 c17-error {{type name does not allow storage class to be specified}} \
16 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
17 } u;
18 };
19
20 enum E : auto { // c23-error {{'auto' not allowed here}} \
21 c17-error {{expected a type}} \
22 c17-error {{type name does not allow storage class to be specified}}
23 One,
24 Two,
25 Tree,
26 };
27
basic_usage(auto auto)28 auto basic_usage(auto auto) { // c23-error {{'auto' not allowed in function prototype}} \
29 c23-error {{'auto' not allowed in function return type}} \
30 c23-error {{cannot combine with previous 'auto' declaration specifier}} \
31 c17-error {{invalid storage class specifier in function declarator}} \
32 c17-error {{illegal storage class on function}} \
33 c17-warning {{duplicate 'auto' declaration specifier}} \
34 c17-warning {{omitting the parameter name in a function definition is a C23 extension}} \
35 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}} \
36 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
37
38 auto = 4; // expected-error {{expected identifier or '('}}
39
40 auto a = 4; // c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
41
42 auto auto aa = 12; // c23-error {{cannot combine with previous 'auto' declaration specifier}} \
43 c17-warning {{duplicate 'auto' declaration specifier}} \
44 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
45
46 auto b[4]; // c23-error {{'auto' not allowed in array declaration}} \
47 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
48
49 auto array[auto]; // expected-error {{expected expression}} \
50 c23-error {{declaration of variable 'array' with deduced type 'auto' requires an initializer}} \
51 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
52
53 AUTO_MACRO(auto, 1, 2, 3); // c23-error {{cannot combine with previous 'auto' declaration specifier}} \
54 expected-error {{expected identifier or '('}} \
55 c17-warning {{duplicate 'auto' declaration specifier}}
56
57 auto c = (auto)a; // expected-error {{expected expression}} \
58 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
59
60 auto ci = (auto){12}; // expected-error {{expected expression}} \
61 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
62
63 int auto_cxx_decl = auto(0); // expected-error {{expected expression}}
64
65 return c;
66 }
67
structs(void)68 void structs(void) {
69 struct s_auto { auto a; }; // c23-error {{'auto' not allowed in struct member}} \
70 c17-error {{type name does not allow storage class to be specified}} \
71 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
72
73 // FIXME: this should end up being rejected when we implement underspecified
74 // declarations in N3006.
75 auto s_int = (struct { int a; } *)0; // c17-error {{incompatible pointer to integer conversion initializing 'int' with an expression of type}} \
76 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
77
78 typedef auto auto_type; // c23-error {{'auto' not allowed in typedef}} \
79 c17-error {{cannot combine with previous 'typedef' declaration specifier}} \
80 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
81 }
82
sizeof_alignas(void)83 void sizeof_alignas(void) {
84 auto auto_size = sizeof(auto); // expected-error {{expected expression}} \
85 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
86 }
87
generic_alignof_alignas(void)88 void generic_alignof_alignas(void) {
89 int g;
90 _Generic(g, auto : 0); // c23-error {{'auto' not allowed here}} \
91 c17-error {{expected a type}} \
92 c17-error {{type name does not allow storage class to be specified}}
93
94 _Alignof(auto); // expected-error {{expected expression}} \
95 expected-warning {{'_Alignof' applied to an expression is a GNU extension}}
96
97 _Alignas(auto); // expected-error {{expected expression}} \
98 expected-warning {{declaration does not declare anything}}
99 }
100
function_designators(void)101 void function_designators(void) {
102 extern auto auto_ret_func(void); // c23-error {{'auto' not allowed in function return type}} \
103 c17-error {{cannot combine with previous 'extern' declaration specifier}} \
104 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
105
106 extern void auto_param_func(auto); // c23-error {{'auto' not allowed in function prototype}} \
107 c17-error {{invalid storage class specifier in function declarator}} \
108 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
109
110 auto (auto_ret_func)(void); // c23-error {{'auto' not allowed in function return type}} \
111 c17-error {{illegal storage class on function}} \
112 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
113
114 void (auto_param_func)(auto); // c23-error {{'auto' not allowed in function prototype}} \
115 c17-error {{invalid storage class specifier in function declarator}} \
116 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
117 }
118
atomic(void)119 void atomic(void) {
120 _Atomic(auto) atom1 = 12; // c23-error {{'auto' not allowed here}} \
121 c23-error {{a type specifier is required for all declarations}} \
122 c17-error {{expected a type}} \
123 c17-error {{type name does not allow storage class to be specified}} \
124 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
125
126 _Atomic auto atom2 = 12; // c23-error {{_Atomic cannot be applied to type 'auto' in C23}} \
127 c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
128 }
129
attributes(void)130 void attributes(void) {
131 auto ident [[clang::annotate("this works")]] = 12; // c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
132 }
133