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Diffstat (limited to 'Documentation/kbuild/kconfig-language.rst')
| -rw-r--r-- | Documentation/kbuild/kconfig-language.rst | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst index 98c24183d8c3..858ed5d80def 100644 --- a/Documentation/kbuild/kconfig-language.rst +++ b/Documentation/kbuild/kconfig-language.rst @@ -176,7 +176,7 @@ applicable everywhere (see syntax). y y y Y/m/n n m n N/m m m m M/n - y m n M/n + y m m M/n y n * N === === ============= ============== @@ -525,8 +525,8 @@ followed by a test macro:: If you need to expose a compiler capability to makefiles and/or C source files, `CC_HAS_` is the recommended prefix for the config option:: - config CC_HAS_ASM_GOTO - def_bool $(success,$(srctree)/scripts/gcc-goto.sh $(CC)) + config CC_HAS_FOO + def_bool $(success,$(srctree)/scripts/cc-check-foo.sh $(CC)) Build as module only ~~~~~~~~~~~~~~~~~~~~ @@ -672,7 +672,7 @@ Future kconfig work Work on kconfig is welcomed on both areas of clarifying semantics and on evaluating the use of a full SAT solver for it. A full SAT solver can be desirable to enable more complex dependency mappings and / or queries, -for instance on possible use case for a SAT solver could be that of handling +for instance one possible use case for a SAT solver could be that of handling the current known recursive dependency issues. It is not known if this would address such issues but such evaluation is desirable. If support for a full SAT solver proves too complex or that it cannot address recursive dependency issues @@ -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 |