http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58001
kargl at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |kargl at gcc dot gnu.org --- Comment #1 from kargl at gcc dot gnu.org --- (In reply to Tobias Burnus from comment #0) > For indenting the source code, gfortran warns only with -std=f* or with > -Wtab. Please, check the archive. At one time gfortran would issue a warning if a tab was used in a nonconforming context. Too many people were upset about this, so the -W[no-]tab option, which has a convoluted history, was the compromise. > However, for format strings, it always warns - and with -std=f* it even > turns the warning into an error! (see io.c's next_char_not_space) > > Example: > > 1894 format( '123') > end > > (The tab is before '123'. A tab in the string itself is not warned for.) > > Maybe the best would be to disable this warning with -std=legacy - and refer > to -std=legacy in the -std=gnu warning? Tab is not and never has been a member of the Fortran character set. The above line of code is nonconforming. Gfortran, IMNSHO, should always issue an error, but I lost that battle years ago.