From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Subject: 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/20220310220927.245704-3-helgaas@xxxxxxxxxx Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Nathan Chancellor <nathan@xxxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: "Michael S . Tsirkin" <mst@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/dev-tools/sparse.rst | 2 ++ include/linux/compiler_types.h | 1 + include/uapi/linux/types.h | 1 + 3 files changed, 4 insertions(+) --- a/Documentation/dev-tools/sparse.rst~documentation-sparse-add-hints-about-__checker__ +++ a/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. --- a/include/linux/compiler_types.h~documentation-sparse-add-hints-about-__checker__ +++ a/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))) --- a/include/uapi/linux/types.h~documentation-sparse-add-hints-about-__checker__ +++ a/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 _