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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /Documentation/kbuild/Kconfig.select-break
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
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+# Select broken dependency issue
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+# Test with:
+#
+# make KBUILD_KCONFIG=Documentation/kbuild/Kconfig.select-break menuconfig
+#
+# kconfig will not complain and enable this layout for configuration. This is
+# currently a feature of kconfig, given select was designed to be heavy handed.
+# Kconfig currently does not check the list of symbols listed on a symbol's
+# "select" list, this is done on purpose to help load a set of known required
+# symbols. Because of this use of select should be used with caution. An
+# example of this issue is below.
+#
+# The option B and C are clearly contradicting with respect to A.
+# However, when A is set, C can be set as well because Kconfig does not
+# visit the dependencies of the select target (in this case B). And since
+# Kconfig does not visit the dependencies, it breaks the dependencies of B
+# (!A).
+
+mainmenu "Simple example to demo kconfig select broken dependency issue"
+
+config A
+ bool "CONFIG A"
+
+config B
+ bool "CONFIG B"
+ depends on !A
+
+config C
+ bool "CONFIG C"
+ depends on A
+ select B