X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=rules.mak;h=49edb9bf07eca605858f5070b9db2340346b7ffd;hb=30c367ed446b6ea53245589a5cf373578ac075d7;hp=abc2e846b3fad0c0f6666edc3de8cce0b1e31c1b;hpb=83f73fce4cf18cf36e99f0e78e8e87dfb6b12a71;p=qemu.git

diff --git a/rules.mak b/rules.mak
index abc2e846b..49edb9bf0 100644
--- a/rules.mak
+++ b/rules.mak
@@ -89,6 +89,34 @@ 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)
+
+# String testing functions: inputs to these can be any string;
+# the output is always either "y" or "n". Leading and trailing whitespace
+# is ignored when comparing strings.
+# String equality
+eq = $(if $(subst $2,,$1)$(subst $1,,$2),n,y)
+# String inequality
+ne = $(if $(subst $2,,$1)$(subst $1,,$2),y,n)
+# Emptiness/non-emptiness tests:
+isempty = $(if $1,n,y)
+notempty = $(if $1,y,n)
+
 # Generate files with tracetool
 TRACETOOL=$(PYTHON) $(SRC_PATH)/scripts/tracetool.py