Hello, * Bruce Korb wrote on Mon, Nov 08, 2010 at 05:29:57PM CET: > On 11/07/10 12:40, Bruno Haible wrote: > >> -extern char *program_name; > >> +char *program_name; > >> ... > >> + char const *p = program_name ? program_name : "unknown"; > > > > No, this is not OK, for two reasons: > > 1) It will cause a link error for all programs that define the > > 'program_name' > > variable, on all non-ELF platforms (mainly MacOS X and Woe32). > > I remember back in the mid-70's writing C code that used that > very technique for declaring external variables. "a.out" format: > char *program_name; > this on a line by itself was both a declaration and a definition. > It strikes me as quite odd that new formats would come along and > require the "extern" keyword to make it a non-definition. I believe > you, but still quite odd.
On OS X that may just be the case because libtool forces -fno-common (for some good reason, but I tend to forget what it was), which disables common sections. Cheers, Ralf
