'--' inserted into MAKEFLAGS

[gk]

I would like to share a little discovery that may cause problems for others 
like me.
There is an undocumented behavior that was driving me crazy until I figured 
out what was going on:
'--' is inserted into MAKEFLAGS before MAKEOVERRIDES is appended, but only 
within the context of command rules.

I don't know if this is a POSIX spec but it can get in the way if you try 
to write a wrapper like XMake, which adds options: the '--' signals end of 
options so any you add after that may not get parsed correctly (depending 
on how you parse options).

I think it would be better for make not to insert the '--' automatically 
since it handles options and overrides fine without it. It only serves to 
trip up people like me :-)

# Makefile
$(warning MAKEFLAGS=$(MAKEFLAGS))
bar:
        #$(warning MAKEFLAGS=$(MAKEFLAGS))
#eof

address@hidden junk]$ make -k FOO=foo bar
Makefile:3: MAKEFLAGS=k
Makefile:5: MAKEFLAGS=k -- FOO=foo

In my application, I define $(XMAKE), similar to $(MAKE), which sometimes 
receives additional options, which must be parsed by my wrapper, xmake.sh. 
Since $(XMAKE) also must include a reference to $(MAKEFLAGS), I was having 
trouble getting past the '--' until I revised my code as follows:

# XMAKEFLAGS includes '-'; Gnu make $(MAKEFLAGS) sometimes does:
# long options start with '--'; if only short options occur, no '-' appears 
in $(MAKEFLAGS)
# Since we may add XMAKE options after $(XMAKE), we can't use preceding 
'--', which appears in $(MAKEFLAGS) when subshells are begun:
# this messes up xmake.sh ability to parse arguments
_MAKEFLAGS=$(filter-out --,$(MAKEFLAGS))
define XMAKE
$(XMAKE_CMD) $(XMAKEFLAGS) -$(patsubst -%,%,$(word 1,$(_MAKEFLAGS))) 
$(wordlist 2,$(words $(_MAKEFLAGS)),$(_MAKEFLAGS))
endef
- Greg Keraunen
http://www.xmake.org