2.18.2 Looking up or entering a string

The function bfd_hash_lookup is used both to look up a string in the hash table and to create a new entry.

If the create argument is FALSE, bfd_hash_lookup will look up a string. If the string is found, it will returns a pointer to a struct bfd_hash_entry. If the string is not found in the table bfd_hash_lookup will return NULL. You should not modify any of the fields in the returns struct bfd_hash_entry.

If the create argument is TRUE, the string will be entered into the hash table if it is not already there. Either way a pointer to a struct bfd_hash_entry will be returned, either to the existing structure or to a newly created one. In this case, a NULL return means that an error occurred.

If the create argument is TRUE, and a new entry is created, the copy argument is used to decide whether to copy the string onto the hash table objalloc or not. If copy is passed as FALSE, you must be careful not to deallocate or modify the string as long as the hash table exists.