Disable make builtin rules and variables from inside the make file
I want to disable builtin rules and variables as per passing the -r
and -R
options to GNU make, from inside the make file. Other solutions that allow me to do this implicitly and transparently are also welcome.
I've found several references to using MAKEFLAGS
, and had similar problems.
Disabling the built-in rules is done by writing an empty rule for .SUFFIXES
:
.SUFFIXES:
Having erased the built-in rules, I'm not sure that erasing the built-in variables helps you much more than just remembering to set them yourself or not use them, but you could use something like
$(foreach V,
$(shell make -p -f/dev/null 2>/dev/null | sed -n '/^[^:#= ]* *=/s/ .*//p'),
$(if $(findstring default,$(origin $V)),$(eval $V=)))
...which is admittedly fairly crazy. If there is a way to get a list of the defined variables from within make (instead of shelling out to another make), it would be viable. As it is, it's not really much better than
CC=
CXX=
# etc, for each likely built-in variable
@hseldon has the right idea because .SUFFIXES doesn't cover the match-everything built-in implicit rules. However, I don't think his syntax is exactly right.
MAKEFLAGS += --no-builtin-rules
.SUFFIXES:
.SUFFIXES: .you .own .here
See http://www.gnu.org/software/make/manual/make.html#Match_002dAnything-Rules and http://www.gnu.org/software/make/manual/make.html#index-g_t_002eSUFFIXES-998