clang/test/Parser/c2x-auto.c

   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
  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
  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
  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
  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
 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
 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
 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 }