%% Boris Kolpackov <[EMAIL PROTECTED]> writes:
bk> I came to the point where I cannot work around "default target
bk> hijacking" problem. So I am planning to do something about it in
bk> my -bk patch-set. I also hope this feature will end up in the main
bk> stream thus this RFC.
bk> When makefile inclusion is used there is a recurring problem of
bk> default target hijacking by auxiliary targets. For example I
bk> have the following pattern:
bk> 1. User `makefile' includes `bootstrap.make' to bootstrap build
bk> system.
bk> 2. `bootstrap.make' includes configuration makefiles that are
bk> generated automatically. Rules for those configuration files
bk> hijack default target.
bk> # file: bootstrap.make
bk> out_root := initialize-output-root
bk> $(out_root)/configuration:
bk> configure $@
bk> include $(out_root)/configuration
bk> # file: makefile
bk> include bootstrap.make
bk> $(out_root)/driver: driver.c
The way I typically solve this is that I always define the target I want
to be the default first, with no prerequisites etc. Simply putting
something like:
all:
by itself at the top of the first makefile is enough to force make to
consider that target to be the default. So, in your example you could
change your makefile to:
# file: makefile
all:
include boostrap.make
all: $(out_root)/driver
$(out_root)/driver: driver.c
Alternatively, if you have a makefile which is always included at the
top (say your bootstrap.make file) you can put the "all" target in that
file as the first thing:
# file: bootstrap.make
.PHONY: all
all:
out_root := initialize-output-root
$(out_root)/configuration:
configure $@
include $(out_root)/configuration
# file: makefile
include boostrap.make
all: $(out_root)/driver
$(out_root)/driver: driver.c
With these methods what you do is declare the "real" default target (or
list of targets) to be a prerequisite of the generic default target,
"all".
bk> This problem can be solved by specifying that particular target
bk> cannot be default:
bk> # file: bootstrap.make
bk> out_root := initialize-output-root
bk> .NOT_DEFAULT: $(out_root)/configuration
bk> $(out_root)/configuration:
bk> configure $@
bk> include $(out_root)/configuration
bk> comments?
Mm. I don't know about this. It seems like it's the wrong way
around... if what you want to have is the default target, why have
people declare everything that _cannot_ be the default? Why not just
declare what _IS_ the default?
--
-------------------------------------------------------------------------------
Paul D. Smith <[EMAIL PROTECTED]> Find some GNU make tips at:
http://www.gnu.org http://make.paulandlesley.org
"Please remain calm...I may be mad, but I am a professional." --Mad Scientist
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