BSD make and '$<'

BSD make and '$<'

[kunihiro]

Using BSD make (I use one coming with FreeBSD), there is problem
around '$<' in Doc/Makefile.in.  But there is no problem making with
GNU make.

Dose anybody know BSD make thinking '$<' should be used always with
implicit rule?  I'm not sure...

% cd zsh-3.0-pre4/Doc
% make -n
makeinfo -I.

% gmake -n
makeinfo -I. zsh.texi

Hmm.  I fixed it like this.

*** Doc/Makefile.in.bak	Wed Jul 31 05:10:00 1996
--- Doc/Makefile.in	Wed Jul 31 05:10:07 1996
***************
*** 93,111 ****
  everything: all zsh_us.ps zsh_a4.ps zsh_toc.html
  
  zsh.info: zsh.texi
! 	-$(MAKEINFO) -I$(srcdir) $<
  
  zsh.dvi: zsh.texi
! 	$(TEXI2DVI) $<
  
  zsh_us.ps: zsh.dvi
! 	$(DVIPS) -t letter -o $@ $<
  
  zsh_a4.ps: zsh.dvi
! 	$(DVIPS) -t a4 -o $@ $<
  
  zsh_toc.html: zsh.texi
! 	$(TEXI2HTML) $<
  
  # ========== DEPENDENCIES FOR INSTALLING ==========
  
--- 93,111 ----
  everything: all zsh_us.ps zsh_a4.ps zsh_toc.html
  
  zsh.info: zsh.texi
! 	-$(MAKEINFO) -I$(srcdir) $?
  
  zsh.dvi: zsh.texi
! 	$(TEXI2DVI) $?
  
  zsh_us.ps: zsh.dvi
! 	$(DVIPS) -t letter -o $@ $?
  
  zsh_a4.ps: zsh.dvi
! 	$(DVIPS) -t a4 -o $@ $?
  
  zsh_toc.html: zsh.texi
! 	$(TEXI2HTML) $?
  
  # ========== DEPENDENCIES FOR INSTALLING ==========
  

Re: BSD make and '$<'

[Zefram]

>Dose anybody know BSD make thinking '$<' should be used always with
>implicit rule?  I'm not sure...

What I know about portable Makefile writing suggests that $< can only
be relied upon in an implicit rule (consider: it could refer to more
than one file, or none, in an explicit rule).  $@ is the only special
variable that is always available in all rules.

>  zsh.info: zsh.texi
>! 	-$(MAKEINFO) -I$(srcdir) $<

So I'm not surprised at the above failing with some makes.

>  zsh.info: zsh.texi
>! 	-$(MAKEINFO) -I$(srcdir) $?

But that's not the best way to fix it -- better to use the actual
filename.

-zefram