We've taken the change to ACPI_TO_POINTER. Thanks, Bob -----Original Message----- From: Qian Cai [mailto:cai@xxxxxx] Sent: Thursday, July 18, 2019 12:49 PM To: Wysocki, Rafael J <rafael.j.wysocki@xxxxxxxxx> Cc: Moore, Robert <robert.moore@xxxxxxxxx>; Schmauss, Erik <erik.schmauss@xxxxxxxxx>; jkim@xxxxxxxxxxx; lenb@xxxxxxxxxx; ndesaulniers@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; devel@xxxxxxxxxx; clang-built-linux@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Qian Cai <cai@xxxxxx> Subject: [PATCH v2] acpica: fix -Wnull-pointer-arithmetic warnings Clang generate quite a few of those warnings. drivers/acpi/scan.c:759:28: warning: arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension [-Wnull-pointer-arithmetic] status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer, ^~~~~~~~~~~~~~~~ ./include/acpi/actypes.h:458:56: note: expanded from macro 'ACPI_ROOT_OBJECT' #define ACPI_ROOT_OBJECT ((acpi_handle) ACPI_TO_POINTER (ACPI_MAX_PTR)) ^~~~~~~~~~~~~~~ ./include/acpi/actypes.h:509:41: note: expanded from macro 'ACPI_TO_POINTER' #define ACPI_TO_POINTER(i) ACPI_ADD_PTR (void, (void *) 0, (acpi_size) (i)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/acpi/actypes.h:503:84: note: expanded from macro 'ACPI_ADD_PTR' #define ACPI_ADD_PTR(t, a, b) ACPI_CAST_PTR (t, (ACPI_CAST_PTR (u8, (a)) + (acpi_size)(b))) ^~~~~~~~~~~~~~~~~ ./include/acpi/actypes.h:501:66: note: expanded from macro 'ACPI_CAST_PTR' #define ACPI_CAST_PTR(t, p) ((t *) (acpi_uintptr_t) (p)) ^ This is because pointer arithmetic on a pointer not pointing to an array is an undefined behavior (C11 6.5.6, constraint 8). Fix it by just casting the corresponding pointers using ACPI_CAST_PTR() and skip the arithmetic. Also, fix a checkpatch warning together. ERROR: Macros with complex values should be enclosed in parentheses #45: FILE: include/acpi/actypes.h:509: +#define ACPI_TO_POINTER(i) ACPI_CAST_PTR (void, i) Signed-off-by: Qian Cai <cai@xxxxxx> --- v2: Use ACPI_CAST_PTR() in ACPI_TO_POINTER() directly without arithmetic. include/acpi/actypes.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index ad6892a24015..163181e2d884 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -506,7 +506,7 @@ typedef u64 acpi_integer; /* Pointer/Integer type conversions */ -#define ACPI_TO_POINTER(i) ACPI_ADD_PTR (void, (void *) 0, (acpi_size) (i)) +#define ACPI_TO_POINTER(i) (ACPI_CAST_PTR (void, i)) #define ACPI_TO_INTEGER(p) ACPI_PTR_DIFF (p, (void *) 0) #define ACPI_OFFSET(d, f) ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0) #define ACPI_PHYSADDR_TO_PTR(i) ACPI_TO_POINTER(i) -- 2.20.1 (Apple Git-117)
