When I build the latest TF-M master with GCC and the 'MinSizeRelease' option, I get the following warning:
tf-m/secure_fw/core/tfm_secure_api.c: In function 'tfm_core_sfn_request_handler':
tf-m/secure_fw/core/tfm_secure_api.c:96:26: error: 'iovec_args' may be used uninitialized in this function [-Werror=maybe-uninitialized]
*(--dst) = (uint32_t)iovec_args->out_vec;
^~~~~~~~~~
tf-m/secure_fw/core/tfm_secure_api.c:365:26: note: 'iovec_args' was declared here
struct iovec_args_t *iovec_args;
^~~~~~~~~~Because we have '-Werror' set, the build fails.
The same warning does not appear with the 'Debug' build type.
The warning is spurious, but I think the easiest solution is probably to modify the code to avoid triggering it.