The non-builtin route for offsetof has a dependency on size_t from stdlib.h/stdint.h that is undeclared and may break targets. The offsetof macro in bpf_helpers may disable the same macro in other headers that have a #ifdef offsetof guard. Rather than add additional dependencies improve the offsetof macro declared here to use the builtin that is available since llvm 3.7 (the first with a BPF backend).
Signed-off-by: Ian Rogers <[email protected]> --- tools/lib/bpf/bpf_helpers.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index a510d8ed716f..bc14db706b88 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -40,7 +40,7 @@ * Helper macro to manipulate data structures */ #ifndef offsetof -#define offsetof(TYPE, MEMBER) ((size_t)&((TYPE *)0)->MEMBER) +#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER) #endif #ifndef container_of #define container_of(ptr, type, member) \ -- 2.28.0.rc0.105.gf9edc3c819-goog
