Patchwork [v2,1/4] rules.mak: New logical functions for handling y/n values

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Submitter Peter Maydell
Date Sept. 13, 2013, 5:25 p.m.
Message ID <1379093154-11348-2-git-send-email-peter.maydell@linaro.org>
Download mbox | patch
Permalink /patch/274832/
State New
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Comments

Peter Maydell - Sept. 13, 2013, 5:25 p.m.
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>
---
 rules.mak |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Patch

diff --git a/rules.mak b/rules.mak
index abc2e84..65a1b96 100644
--- a/rules.mak
+++ b/rules.mak
@@ -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