Date: Fri, 9 Mar 2001 01:30:01 -0800 (PST) (10:30 CET)
To: jhs@_ERASE_.
From: gnats-admin@FreeBSD._ERASE_..org
Subject: Re: bin/25627: Cannot append hash after .elif in Makefile, (but can after .if)

Thank you very much for your problem report.
It has the internal identification `bin/25627'.
The individual assigned to look at your
report is: freebsd-bugs. 

You can access the state of your problem report at any time
via this link:

http://www.freebsd.org/cgi/query-pr.cgi?pr=25627

SEND-PR: -*- send-pr -*-
SEND-PR: Lines starting with `SEND-PR' will be removed automatically, as
SEND-PR: will all comments (text enclosed in `<' and `>').
SEND-PR: 
SEND-PR: Please consult the send-pr man page `send-pr(1)' or the Texinfo
SEND-PR: manual if you are not sure how to fill out a problem report.
SEND-PR:
SEND-PR: Note that the Synopsis field is mandatory.  The Subject (for
SEND-PR: the mail) will be made the same as Synopsis unless explicitly
SEND-PR: changed.
SEND-PR:
SEND-PR: Choose from the following categories:
SEND-PR:
SEND-PR: advocacy alpha    bin      conf     docs     gnu      
SEND-PR: i386     kern     misc     ports    sparc    
SEND-PR:
To: FreeBSD-gnats-submit@freebsd.._ERASE_.org
Subject: Cannot append hash after .elif in Makefile, (but can after .if)
From: jhs@._ERASE_.
Reply-To: jhs@._ERASE_.
X-send-pr-version: 3.2


>Submitter-Id:   current-users
>Originator:     Julian Stacey jhs@._ERASE_.
>Organization:   FreeBSD
>Confidential:   no
>Synopsis:       Cannot append hash after .elif in Makefile, (but can after .if)
>Severity:       non-critical
>Priority:       low
>Category:       bin
>Release:        FreeBSD 4.2-RELEASE i386
>Class:          sw-bug
>Environment: 

`man make` says:
  Comments begin with a hash (`#') character, anywhere but in a shell com-
  mand line, and continue to the end of the line.

To understand a complex Makefile like /usr/src/release/Makefile
with nested .if .endif conditionals, it is useful to hang "#{" & "#}"
at end of lines & use the "%" key in vi to bounce between matching braces.
This fails on .elif

>Description: 

The expansion of .elif uses everything up to '\n' & allows no
'#' comment delimeter as available to simpler .if & .else & .endif commands.

>How-To-Repeat: 

mkdir ~/tmp ; cd ~/tmp ; cat > Makefile << EOF
break:
.if defined(AA)		#{AA
	@echo 11
.elif defined(BB)	#}{!AA{BB
	@echo 22
.else			#}{!BB
	@echo 33
.endif			#}}

ok:
.if defined(AA)		#{AA
	@echo 11
.else			#}{!AA
.if defined(BB)		#{BB
	@echo 22
.else			#}{!BB
	@echo 33
.endif			#}
.endif			#}
EOF
make

"Makefile", line 4: Malformed conditional (defined(BB)  #}{!AA{BB)
make: fatal errors encountered -- cannot continue

>Fix: 
Document it - until a make guru fixes it sometime, maybe.
*** 4.8-RELEASE/src/usr.bin/make/make.1	Thu Oct 19 06:23:49 2000
--- new/src/usr.bin/make/make.1	Thu Mar  8 16:53:43 2001
***************
*** 1238,1243 ****
--- 1238,1273 ----
  \&.endfor
  .Ed
  won't work, and should be rewritten the other way around.
+ .Pp
+ The expansion of .elif uses everything up to end of line, & allows no
+ # comment delimeter as available to simpler .if & .else & .endif commands.
+ .br
+ This thus fails;
+ .in +2
+ .nf
+  .if defined(AA)         #{AA
+          @echo 11
+  .elif defined(BB)       #}{!AA{BB
+          @echo 22
+  .else                   #}{!BB
+          @echo 33
+  .endif                  #}}
+ .fi
+ .in -2
+ Whereas this works
+ .in +2
+ .nf
+  .if defined(AA)         #{AA
+          @echo 11
+  .else                   #}{!AA
+  .if defined(BB)         #{BB
+          @echo 22
+  .else                   #}{!BB
+          @echo 33
+  .endif                  #}
+  .endif                  #}
+ .fi
+ .in -2
  .Sh SEE ALSO
  .Xr mkdep 1
  .Rs