What declarations of objects in C force storage to be stored (i.e. are definitions)?

Question

C11 indicates in section 6.7 which declarations are also definitions:

The definition of an identifier is an announcement for this identifier that: - for an object, causes the storage to be reserved for this object;
[...]

I did not find an exhaustive list of statements about which object declarations are reserved. It is intuitive to me, but I could not get this information from the C11 standard.

Answer 1

, , , . . int - (, const) .

• , :

  int x = 1;
  

• , :

  int x;
  auto int x;        // auto is the default anyways
  register int x;    // register is just a hint, but would be "storage" as well
  static int x;      // also reserves storage, but with static duration
  

• ; :

  int x;
  static int x;
  

  (§6.9.2p2):

  , , static, . , , , 0

  , " ", .

• extern :

  extern int x;     // <- not a definition
  

AFAIK, . , /, - .