Documentation/sparse: add hints about __CHECKER__

Several attributes depend on __CHECKER__, but previously there was no clue in the tree about when __CHECKER__ might be defined. Add hints at the most common places (__kernel, __user, __iomem, __bitwise) and in the sparse documentation. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Bjorn Helgaas <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: "Michael S . Tsirkin" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
wafgo · Mar 24, 2022 · 179fd6b · 179fd6b
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diff --git a/Documentation/dev-tools/sparse.rst b/Documentation/dev-tools/sparse.rst
@@ -100,3 +100,5 @@ have already built it.
 
 The optional make variable CF can be used to pass arguments to sparse.  The
 build system passes -Wbitwise to sparse automatically.
+
+Note that sparse defines the __CHECKER__ preprocessor symbol.
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
@@ -4,6 +4,7 @@
 
 #ifndef __ASSEMBLY__
 
+/* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
 #ifdef __CHECKER__
 /* address spaces */
 # define __kernel	__attribute__((address_space(0)))

diff --git a/include/uapi/linux/types.h b/include/uapi/linux/types.h
@@ -19,6 +19,7 @@
  * any application/library that wants linux/types.h.
  */
 
+/* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
 #ifdef __CHECKER__
 #define __bitwise	__attribute__((bitwise))
 #else
Original file line number	Diff line number	Diff line change
Expand Up		@@ -100,3 +100,5 @@ have already built it.

		The optional make variable CF can be used to pass arguments to sparse. The
		build system passes -Wbitwise to sparse automatically.

		Note that sparse defines the __CHECKER__ preprocessor symbol.