rules.mak: New logical functions for handling y/n values

Add new logical functions for handling y/n values like those we
use in CONFIG_FOO variables:
 lnot : logical NOT
 land : logical AND
 lor : logical OR
 lxor : logical XOR
 leqv : logical equality, inverse of lxor
 lif : like Make's $(if) but with an eq-like test

Based on an idea by Ákos Kovács <akoskovacs@gmx.com>.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Maydell 2013-09-13 18:25:51 +01:00 committed by Paolo Bonzini
parent 39c153b80f
commit 837a2e267f

View File

@ -89,6 +89,23 @@ find-in-path = $(if $(find-string /, $1), \
$(wildcard $1), \
$(wildcard $(patsubst %, %/$1, $(subst :, ,$(PATH)))))
# Logical functions (for operating on y/n values like CONFIG_FOO vars)
# Inputs to these must be either "y" (true) or "n" or "" (both false)
# Output is always either "y" or "n".
# Usage: $(call land,$(CONFIG_FOO),$(CONFIG_BAR))
# Logical NOT
lnot = $(if $(subst n,,$1),n,y)
# Logical AND
land = $(if $(findstring yy,$1$2),y,n)
# Logical OR
lor = $(if $(findstring y,$1$2),y,n)
# Logical XOR (note that this is the inverse of leqv)
lxor = $(if $(filter $(call lnot,$1),$(call lnot,$2)),n,y)
# Logical equivalence (note that leqv "","n" is true)
leqv = $(if $(filter $(call lnot,$1),$(call lnot,$2)),y,n)
# Logical if: like make's $(if) but with an leqv-like test
lif = $(if $(subst n,,$1),$2,$3)
# Generate files with tracetool
TRACETOOL=$(PYTHON) $(SRC_PATH)/scripts/tracetool.py