* Stefano Lattarini wrote on Wed, Dec 22, 2010 at 06:17:47PM CET: > [stemming from discussion about automake bug#7657: > <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=7657>] > > On Tuesday 21 December 2010, Ralf Wildenhues wrote: > > * Stefano Lattarini wrote on Tue, Dec 21, 2010 at 01:55:39PM CET: > > > On Sunday 19 December 2010, Ralf Wildenhues wrote: > > > > * Stefano Lattarini wrote on Fri, Dec 17, 2010 at 12:19:40PM CET: > > > > > xmandir = $(mandir) # we want info files installed in $(mandir) > > > > > because ... > > > > > xman_TEXINFOS = foo.texi > > > > > > > > (And the inline comment is of course not ok ;-) > > > > > > (Maybe it's time to deprecate them too in the manual ...) > > > > I don't see how they were ever not problematic. Well, at least given > > the autoconf.texi general warnings about comments in makefiles. > > > Ah, but AFAIK, make comments are problematic only in makefile *rules*, > not in variable definitions: > VAR = foo bar # a probably portable comment > tgt:; touch $@ # a bad unportable commen
Not quite. The above comment in the variable definition is not unportable, but it is unobvious: For a Posix make, the above defines VAR to be 'foo bar '. Note the trailing space! If automake parses it differently, then that is a semantic difference to how Posix make reads its input. (We may have a couple such differences already, but in general, they are not desirable.) What you are hinting at is # signs within quoted parts of a variable definition, like '#' or "#" or more complex things. Posix notes: Because of widespread historical practice, interpreting a '#' number sign inside a variable as the start of a comment has the unfortunate side effect of making it impossible to place a number sign in a variable, thus forbidding something like: CFLAGS = "-D COMMENT_CHAR='#'" but most modern makes treat quoted content differently. (No, I have not done research as to how exactly quoted content is defined by the various make implementations. I'm sure there are variations here as well.) Cheers, Ralf
