clang/test/Sema/alignas.c

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c11 -Dalignof=__alignof %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -std=c11 -Dalignof=_Alignof -DUSING_C11_SYNTAX %s
   3 // RUN: %clang_cc1 -fsyntax-only -verify -std=c23 -DUSING_C11_SYNTAX %s
   4
   5 _Alignas(3) int align_illegal; //expected-error {{requested alignment is not a power of 2}}
   6 _Alignas(int) char align_big;
   7 _Alignas(1) int align_small; // expected-error {{requested alignment is less than minimum}}
   8 _Alignas(1) unsigned _Alignas(8) int _Alignas(1) align_multiple;
   9
  10 struct align_member {
  11   _Alignas(8) int member;
  12   _Alignas(1) char bitfield : 1; // expected-error {{'_Alignas' attribute cannot be applied to a bit-field}}
  13 };
  14
  15 typedef _Alignas(8) char align_typedef; // expected-error {{'_Alignas' attribute only applies to variables and fields}}
  16
  17 void f(_Alignas(1) char c) { // expected-error {{'_Alignas' attribute cannot be applied to a function parameter}}
  18   _Alignas(1) register char k; // expected-error {{'_Alignas' attribute cannot be applied to a variable with 'register' storage class}}
  19 }
  20
  21 #ifdef USING_C11_SYNTAX
  22 // expected-warning-re@+4{{'{{(_A|a)}}lignof' applied to an expression is a GNU extension}}
  23 // expected-warning-re@+4{{'{{(_A|a)}}lignof' applied to an expression is a GNU extension}}
  24 // expected-warning-re@+4{{'{{(_A|a)}}lignof' applied to an expression is a GNU extension}}
  25 #endif
  26 _Static_assert(alignof(align_big) == alignof(int), "k's alignment is wrong");
  27 _Static_assert(alignof(align_small) == 1, "j's alignment is wrong");
  28 _Static_assert(alignof(align_multiple) == 8, "l's alignment is wrong");
  29 _Static_assert(alignof(struct align_member) == 8, "quuux's alignment is wrong");
  30 _Static_assert(sizeof(struct align_member) == 8, "quuux's size is wrong");
  31
  32 struct GH95032_1 {
  33   _Alignas(16) char bytes[16];
  34 };
  35 _Static_assert(_Alignof(struct GH95032_1) == 16, "");
  36
  37 #if __STDC_VERSION__ >= 202311L
  38 struct GH95032_2 {
  39   alignas(16) char bytes[16];
  40 };
  41 static_assert(alignof(struct GH95032_2) == 16);
  42 #endif