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authorNecip Fazil Yildiran <fazilyildiran@gmail.com>2022-04-05 00:33:51 -0400
committerMasahiro Yamada <masahiroy@kernel.org>2022-04-06 19:27:41 +0900
commitcab802b7b8c9eea6fe30161dab77a05d20d76195 (patch)
tree26ca8ff2ca7fd65b6a2aed8a89a63bcb76a8474c
parentd5ea4fece4508bf8e72b659cd22fa4840d8d61e5 (diff)
docs: kbuild: add references on Kconfig semantics
Add references to 1) a research paper which provides a definition of Kconfig semantics, 2) the kismet tool, which checks for unmet direct dependency bugs in Kconfig specifications. Signed-off-by: Paul Gazzillo <paul@pgazz.com> Signed-off-by: Necip Fazil Yildiran <fazilyildiran@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
-rw-r--r--Documentation/kbuild/kconfig-language.rst6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst
index 93a5b6e1fabd..a7173843a294 100644
--- a/Documentation/kbuild/kconfig-language.rst
+++ b/Documentation/kbuild/kconfig-language.rst
@@ -693,6 +693,8 @@ in documenting basic Kconfig syntax a more precise definition of Kconfig
semantics is welcomed. One project deduced Kconfig semantics through
the use of the xconfig configurator [1]_. Work should be done to confirm if
the deduced semantics matches our intended Kconfig design goals.
+Another project formalized a denotational semantics of a core subset of
+the Kconfig language [10]_.
Having well defined semantics can be useful for tools for practical
evaluation of dependencies, for instance one such case was work to
@@ -700,6 +702,8 @@ express in boolean abstraction of the inferred semantics of Kconfig to
translate Kconfig logic into boolean formulas and run a SAT solver on this to
find dead code / features (always inactive), 114 dead features were found in
Linux using this methodology [1]_ (Section 8: Threats to validity).
+The kismet tool, based on the semantics in [10]_, finds abuses of reverse
+dependencies and has led to dozens of committed fixes to Linux Kconfig files [11]_.
Confirming this could prove useful as Kconfig stands as one of the leading
industrial variability modeling languages [1]_ [2]_. Its study would help
@@ -738,3 +742,5 @@ https://kernelnewbies.org/KernelProjects/kconfig-sat
.. [7] https://vamos.cs.fau.de
.. [8] https://undertaker.cs.fau.de
.. [9] https://www4.cs.fau.de/Publications/2011/tartler_11_eurosys.pdf
+.. [10] https://paulgazzillo.com/papers/esecfse21.pdf
+.. [11] https://github.com/paulgazz/kmax