clang/test/C/drs/dr5xx.c

   1 /* RUN: %clang_cc1 -std=c89 -verify=expected,c89only -pedantic -Wno-c11-extensions %s
   2    RUN: %clang_cc1 -std=c99 -verify=expected -pedantic -Wno-c11-extensions %s
   3    RUN: %clang_cc1 -std=c11 -verify=expected -pedantic %s
   4    RUN: %clang_cc1 -std=c17 -verify=expected -pedantic %s
   5    RUN: %clang_cc1 -std=c2x -verify=expected -pedantic %s
   6  */
   7
   8 /* WG14 DR502:
   9  * Flexible array member in an anonymous struct
  10  */
  11 void dr502(void) {
  12   /* This is EXAMPLE 3 from 6.7.2.1 and is intended to show that a flexible
  13    * array member can be used when the only other members of the class are from
  14    * an anonymous structure member.
  15    */
  16   struct s {
  17     struct { int i; };
  18     int a[]; /* c89only-warning {{flexible array members are a C99 feature}} */
  19   };
  20
  21   /* This is a slightly modified example that looks to see whether the
  22    * anonymous structure itself can provide a flexible array member for the
  23    * containing class.
  24    *
  25    * The committee does not think this is valid because it would mean the
  26    * anonymous structure would have size 0. Additionally, the anonymous
  27    * structure has no additional members and so the flexible array member is
  28    * not valid within the anonymous structure.
  29    */
  30   struct t {
  31     int i;
  32     struct { int a[]; }; /* expected-error {{flexible array member 'a' not allowed in otherwise empty struct}}
  33                             c89only-warning {{flexible array members are a C99 feature}}
  34                             expected-warning {{'' may not be nested in a struct due to flexible array member}}
  35                           */
  36   };
  37 }
  38