On Fri, Jun 06, 2025 at 09:51:29AM +0200, Michal Luczaj wrote:
On 6/5/25 12:46, Stefano Garzarella wrote:
On Wed, Jun 04, 2025 at 09:10:19PM +0200, Michal Luczaj wrote:
On 6/4/25 11:07, Stefano Garzarella wrote:
On Wed, May 28, 2025 at 10:44:42PM +0200, Michal Luczaj wrote:
+static int __get_transports(void)
+{
+ /* Order must match transports defined in util.h.
+ * man nm: "d" The symbol is in the initialized data section.
+ */
+ const char * const syms[] = {
+ "d loopback_transport",
+ "d virtio_transport",
+ "d vhost_transport",
+ "d vmci_transport",
+ "d hvs_transport",
+ };
I would move this array (or a macro that define it), near the transport
defined in util.h, so they are near and we can easily update/review
changes.
BTW what about adding static asserts to check we are aligned?
Something like
#define KNOWN_TRANSPORTS \
What about KNOWN_TRANSPORTS(_) ?
Ah, yeah.
_(LOOPBACK, "loopback") \
_(VIRTIO, "virtio") \
_(VHOST, "vhost") \
_(VMCI, "vmci") \
_(HYPERV, "hvs")
enum transport {
TRANSPORT_COUNTER_BASE = __COUNTER__ + 1,
#define _(name, symbol) \
TRANSPORT_##name = _BITUL(__COUNTER__ - TRANSPORT_COUNTER_BASE),
KNOWN_TRANSPORTS
TRANSPORT_NUM = __COUNTER__ - TRANSPORT_COUNTER_BASE,
#undef _
};
static char * const transport_ksyms[] = {
#define _(name, symbol) "d " symbol "_transport",
KNOWN_TRANSPORTS
#undef _
};
static_assert(ARRAY_SIZE(transport_ksyms) == TRANSPORT_NUM);
?
Yep, this is even better, thanks :-)
Although checkpatch complains:
ERROR: Macros with complex values should be enclosed in parentheses
#105: FILE: tools/testing/vsock/util.h:11:
+#define KNOWN_TRANSPORTS(_) \
+ _(LOOPBACK, "loopback") \
+ _(VIRTIO, "virtio") \
+ _(VHOST, "vhost") \
+ _(VMCI, "vmci") \
+ _(HYPERV, "hvs")
BUT SEE:
do {} while (0) advice is over-stated in a few situations:
The more obvious case is macros, like MODULE_PARM_DESC, invoked at
file-scope, where C disallows code (it must be in functions). See
$exceptions if you have one to add by name.
More troublesome is declarative macros used at top of new scope,
like DECLARE_PER_CPU. These might just compile with a do-while-0
wrapper, but would be incorrect. Most of these are handled by
detecting struct,union,etc declaration primitives in $exceptions.
Theres also macros called inside an if (block), which "return" an
expression. These cannot do-while, and need a ({}) wrapper.
Enjoy this qualification while we work to improve our heuristics.
ERROR: Macros with complex values should be enclosed in parentheses
#114: FILE: tools/testing/vsock/util.h:20:
+ #define _(name, symbol) \
+ TRANSPORT_##name = BIT(__COUNTER__ - TRANSPORT_COUNTER_BASE),
WARNING: Argument 'symbol' is not used in function-like macro
#114: FILE: tools/testing/vsock/util.h:20:
+ #define _(name, symbol) \
+ TRANSPORT_##name = BIT(__COUNTER__ - TRANSPORT_COUNTER_BASE),
WARNING: Argument 'name' is not used in function-like macro
#122: FILE: tools/testing/vsock/util.h:28:
+ #define _(name, symbol) "d " symbol "_transport",
Is it ok to ignore this? FWIW, I see the same ERRORs due to similarly used
preprocessor directives in fs/bcachefs/alloc_background_format.h, and the
same WARNINGs about unused macro arguments in arch/x86/include/asm/asm.h
(e.g. __ASM_SEL).
It's just test, so I think it's fine to ignore, but please exaplain it
in the commit description with also references to other ERRORs/WARNINGs
like you did here. Let's see what net maintainers think.
Thanks,
Stefano
