>Number:         4778
>Category:       bin
>Synopsis:       make .if empty() breaks with .for formal
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people (Utility Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jan  5 05:05:02 1998
>Last-Modified:
>Originator:     der Mouse
>Organization:
	Dis-
>Release:        1.3
>Environment:
	NetBSD/sparc on a SS1+
>Description:
	make(1)'s .if empty() directive breaks when used to test a
	(modified form of a) loop formal of a .for loop; make reacts as
	though the loop formal were undefined.  (The "Malformed
	conditional" error below is the same error I get when I apply
	.if empty() to an undefined variable.)
>How-To-Repeat:
	% cat z
	FOO != echo x; echo FLARP is $(FLARP) 1>&2
	.for x in $(FLARP)
	.if empty(x:E:Na)
	FOO != echo x; echo the .if is true 1>&2
	.else
	FOO != echo x; echo the .if is false 1>&2
	.endif
	.endfor
	% make -f z FLARP='foo.a bar.so'
	FLARP is foo.a bar.so
	"z", line 1: Malformed conditional (empty(x:E:Na))
	"z", line 1: Missing dependency operator
	the .if is true
	"z", line 3: if-less else
	"z", line 3: Need an operator
	the .if is false
	"z", line 5: if-less endif
	"z", line 5: Need an operator
	"z", line 1: Malformed conditional (empty(x:E:Na))
	"z", line 1: Missing dependency operator
	the .if is true
	"z", line 3: if-less else
	"z", line 3: Need an operator
	the .if is false
	"z", line 5: if-less endif
	"z", line 5: Need an operator
	Fatal errors encountered -- cannot continue
	% diff z z2
	3c3,4
	< .if empty(x:E:Na)
	---
	> BAR := $(x:E:Na)
	> .if empty(BAR)
	% make -f z2 FLARP='foo.a bar.so'
	FLARP is foo.a bar.so
	the .if is true
	the .if is false
	make: no target to make.
	% 
>Fix:
	I suspect that .for loops are implemented by constructing
	transient makefile segments consisting of the body with the
	iteration variable substituted out, which would explain several
	oddities I've seen, including this bug.  If so, about the only
	hope is a reimplementation of .for, though in the interim it
	would probably be a workable substitute to splatter warnings
	all over the man page that .for loop formals do not work as
	empty() arguments (and other such situations, if any).

					der Mouse

			       mouse@rodents.montreal.qc.ca
		     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B
>Audit-Trail:
>Unformatted: