llvm-project

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// RUN: %clang_cc1 -fsyntax-only -verify=expected,c23 -std=c23 %s
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// RUN: %clang_cc1 -fsyntax-only -verify=expected,c17 -std=c17 %s
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#define AUTO_MACRO(_NAME, ARG, ARG2, ARG3) \
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auto _NAME = ARG + (ARG2 / ARG3);
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struct S {
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  int a;
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  auto b;       // c23-error {{'auto' not allowed in struct member}} \
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                   c17-error {{type name does not allow storage class to be specified}} \
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                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  union {
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    char c;
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    auto smth;  // c23-error {{'auto' not allowed in union member}} \
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                   c17-error {{type name does not allow storage class to be specified}} \
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                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  } u;
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};
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enum E : auto { // c23-error {{'auto' not allowed here}} \
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                   c17-error {{expected a type}} \
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                   c17-error {{type name does not allow storage class to be specified}}
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  One,
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  Two,
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  Tree,
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};
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auto basic_usage(auto auto) {   // c23-error {{'auto' not allowed in function prototype}} \
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                                   c23-error {{'auto' not allowed in function return type}} \
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                                   c23-error {{cannot combine with previous 'auto' declaration specifier}} \
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                                   c17-error {{invalid storage class specifier in function declarator}} \
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                                   c17-error {{illegal storage class on function}} \
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                                   c17-warning {{duplicate 'auto' declaration specifier}} \
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                                   c17-warning {{omitting the parameter name in a function definition is a C23 extension}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  auto = 4;                     // expected-error {{expected identifier or '('}}
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  auto a = 4;                   // c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  auto auto aa = 12;            // c23-error {{cannot combine with previous 'auto' declaration specifier}} \
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                                   c17-warning {{duplicate 'auto' declaration specifier}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  auto b[4];                    // c23-error {{'auto' not allowed in array declaration}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  auto array[auto];             // expected-error {{expected expression}} \
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                                   c23-error {{declaration of variable 'array' with deduced type 'auto' requires an initializer}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  AUTO_MACRO(auto, 1, 2, 3);    // c23-error {{cannot combine with previous 'auto' declaration specifier}} \
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                                   expected-error {{expected identifier or '('}} \
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                                   c17-warning {{duplicate 'auto' declaration specifier}}
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  auto c = (auto)a;             // expected-error {{expected expression}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  auto ci = (auto){12};         // expected-error {{expected expression}} \
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                                   c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  int auto_cxx_decl = auto(0);  // expected-error {{expected expression}}
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  return c;
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}
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void structs(void) {
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  struct s_auto { auto a; };            // c23-error {{'auto' not allowed in struct member}} \
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                                           c17-error {{type name does not allow storage class to be specified}} \
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                                           c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  // FIXME: this should end up being rejected when we implement underspecified
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  // declarations in N3006.
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  auto s_int = (struct { int a; } *)0;  // c17-error {{incompatible pointer to integer conversion initializing 'int' with an expression of type}} \
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                                           c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  typedef auto auto_type;               // c23-error {{'auto' not allowed in typedef}} \
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                                           c17-error {{cannot combine with previous 'typedef' declaration specifier}} \
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                                           c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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}
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void sizeof_alignas(void) {
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  auto auto_size = sizeof(auto);  // expected-error {{expected expression}} \
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                                     c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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}
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void generic_alignof_alignas(void) {
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  int g;
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  _Generic(g, auto : 0);  // c23-error {{'auto' not allowed here}} \
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                             c17-error {{expected a type}} \
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                             c17-error {{type name does not allow storage class to be specified}}
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  _Alignof(auto);         // expected-error {{expected expression}} \
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                             expected-warning {{'_Alignof' applied to an expression is a GNU extension}}
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  _Alignas(auto);         // expected-error {{expected expression}} \
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                             expected-warning {{declaration does not declare anything}}
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}
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void function_designators(void) {
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  extern auto auto_ret_func(void);    // c23-error {{'auto' not allowed in function return type}} \
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                                         c17-error {{cannot combine with previous 'extern' declaration specifier}} \
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                                         c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  extern void auto_param_func(auto);  // c23-error {{'auto' not allowed in function prototype}} \
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                                         c17-error {{invalid storage class specifier in function declarator}} \
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                                         c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  auto (auto_ret_func)(void);         // c23-error {{'auto' not allowed in function return type}} \
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                                         c17-error {{illegal storage class on function}} \
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                                         c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  void (auto_param_func)(auto);       // c23-error {{'auto' not allowed in function prototype}} \
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                                         c17-error {{invalid storage class specifier in function declarator}} \
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                                         c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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}
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void atomic(void) {
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  _Atomic(auto) atom1 = 12; // c23-error {{'auto' not allowed here}} \
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                               c23-error {{a type specifier is required for all declarations}} \
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                               c17-error {{expected a type}} \
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                               c17-error {{type name does not allow storage class to be specified}} \
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                               c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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  _Atomic auto atom2 = 12;  // c23-error {{_Atomic cannot be applied to type 'auto' in C23}} \
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                               c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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}
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void attributes(void) {
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  auto ident [[clang::annotate("this works")]] = 12;  // c17-error {{type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int}}
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}
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