-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warnings:

drivers/platform/chrome/cros_ec_proto.c:143:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/platform/chrome/cros_ec_proto.c:761:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/platform/chrome/cros_ec_proto.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 877b107fee4b..586358fbf981 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -139,12 +139,10 @@ static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_co
 
 static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
 {
-	struct {
-		struct cros_ec_command msg;
-		struct ec_response_get_comms_status status;
-	} __packed buf;
-	struct cros_ec_command *msg = &buf.msg;
-	struct ec_response_get_comms_status *status = &buf.status;
+	DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+			sizeof(struct ec_response_get_comms_status));
+	struct ec_response_get_comms_status *status =
+			(struct ec_response_get_comms_status *)msg->data;
 	int ret = 0, i;
 
 	msg->version = 0;
@@ -757,16 +755,13 @@ static int get_next_event_xfer(struct cros_ec_device *ec_dev,
 
 static int get_next_event(struct cros_ec_device *ec_dev)
 {
-	struct {
-		struct cros_ec_command msg;
-		struct ec_response_get_next_event_v3 event;
-	} __packed buf;
-	struct cros_ec_command *msg = &buf.msg;
-	struct ec_response_get_next_event_v3 *event = &buf.event;
+	DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+			sizeof(struct ec_response_get_next_event_v3));
+	struct ec_response_get_next_event_v3 *event =
+			(struct ec_response_get_next_event_v3 *)msg->data;
 	int cmd_version = ec_dev->mkbp_event_supported - 1;
 	u32 size;
 
-	memset(msg, 0, sizeof(*msg));
 	if (ec_dev->suspended) {
 		dev_dbg(ec_dev->dev, "Device suspended.\n");
 		return -EHOSTDOWN;
-- 
2.43.0

On Fri, Mar 28, 2025 at 07:00:15AM -0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
> 
> Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
> a flexible structure where the size of the flexible-array member
> is known at compile-time, and refactor the rest of the code,
> accordingly.
> 
> [...]

Applied to

    https://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux.git for-next

[1/1] platform/chrome: cros_ec_proto: Avoid -Wflex-array-member-not-at-end warnings
      commit: db4ea66acddf95b4bb13ef17537097820218fb7a

Thanks!

On Fri, Mar 28, 2025 at 07:00:15AM -0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
> 
> Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
> a flexible structure where the size of the flexible-array member
> is known at compile-time, and refactor the rest of the code,
> accordingly.
> 
> So, with these changes, fix the following warnings:
> 
> drivers/platform/chrome/cros_ec_proto.c:143:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> drivers/platform/chrome/cros_ec_proto.c:761:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
> 
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

For my reference:
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>