I guess you're right. I actually write C++, where extern is necessary to do more or less what ENTRY does in assembler, and no, I can't cite chapter and verse but I just commented out an extern keyword on a definition and the link failed "unresolved."
Obviously in any language you need a definition somewhere. Otherwise everyone is just declaring "this exists somewhere else." It has to actually exist somewhere. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Webster, Chris Sent: Tuesday, August 18, 2015 5:01 PM To: [email protected] Subject: C extern was RE: Resolving EXTRN References There is still supposed to be a definition in C that does NOT have extern specified. It is quite common to just use extern declarations and most compilers account for this. Quoting IBM: An extern declaration makes the described variable usable by the succeeding part of the current source file. This declaration does not replace the definition. The declaration is used to describe the variable that is externally defined. IOW, the definition is the one true instance. It should be the only one with an initializer or things get confusing. ...chris. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Charles Mills Sent: Tuesday, August 18, 2015 4:05 PM To: [email protected] Subject: Re: Resolving EXTRN References Different from C, where you use extern on both ends. Charles ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
