Zero-length arrays as fake flexible arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead.
Use the DECLARE_FLEX_ARRAY() helper macro to transform zero-length arrays in unions with flexible-array members.
Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: sound/soc/sof/ipc4-control.c:176:77: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:78:29: warning: array subscript 0 is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:80:33: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:95:53: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:96:53: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:93:53: warning: array subscript 0 is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:140:58: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:141:29: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-control.c:142:29: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-topology.c:1475:36: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=] sound/soc/sof/ipc4-topology.c:1476:36: warning: array subscript i is outside array bounds of ‘struct sof_ipc4_ctrl_value_chan[0]’ [-Warray-bounds=]
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/21 Link: https://github.com/KSPP/linux/issues/193 Link: https://github.com/KSPP/linux/issues/258 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org --- sound/soc/sof/ipc4-topology.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/soc/sof/ipc4-topology.h b/sound/soc/sof/ipc4-topology.h index 72529179ac22..8507171a6e4d 100644 --- a/sound/soc/sof/ipc4-topology.h +++ b/sound/soc/sof/ipc4-topology.h @@ -266,8 +266,8 @@ struct sof_ipc4_control_data { int index;
union { - struct sof_ipc4_ctrl_value_chan chanv[0]; - struct sof_abi_hdr data[0]; + DECLARE_FLEX_ARRAY(struct sof_ipc4_ctrl_value_chan, chanv); + DECLARE_FLEX_ARRAY(struct sof_abi_hdr, data); }; };