summaryrefslogtreecommitdiffstats
path: root/Documentation/kbuild/Kconfig.select-break
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/kbuild/Kconfig.select-break
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/kbuild/Kconfig.select-break')
-rw-r--r--Documentation/kbuild/Kconfig.select-break33
1 files changed, 33 insertions, 0 deletions
diff --git a/Documentation/kbuild/Kconfig.select-break b/Documentation/kbuild/Kconfig.select-break
new file mode 100644
index 000000000..365ceb342
--- /dev/null
+++ b/Documentation/kbuild/Kconfig.select-break
@@ -0,0 +1,33 @@
+# 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