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-rw-r--r--Documentation/kbuild/kconfig-language.txt18
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
index 0e966e8f9ec7..a4eb01843c04 100644
--- a/Documentation/kbuild/kconfig-language.txt
+++ b/Documentation/kbuild/kconfig-language.txt
@@ -473,6 +473,24 @@ config option to 'y' no matter the dependencies.
The dependencies are moved to the symbol GENERIC_IOMAP and we avoid the
situation where select forces a symbol equals to 'y'.
+Adding features that need compiler support
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+There are several features that need compiler support. The recommended way
+to describe the dependency on the compiler feature is to use "depends on"
+followed by a test macro.
+
+config CC_STACKPROTECTOR
+ bool "Stack Protector buffer overflow detection"
+ depends on $(cc-option,-fstack-protector)
+ ...
+
+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_STACKPROTECTOR_NONE
+ def_bool $(cc-option,-fno-stack-protector)
+
Build as module only
~~~~~~~~~~~~~~~~~~~~
To restrict a component build to module-only, qualify its config symbol