arch: riscv: Fix warning when C++ is enabled
When compiling with C++ enabled (CONFIG_CPP), add an unused member to
prevent an empty struct; this makes the struct size the same for both C
and C++.
Fixes the following warnings:
In file included from include/zephyr/drivers/gpio.h:22:
In file included from include/zephyr/tracing/tracing.h:9:
In file included from include/zephyr/kernel.h:17:
In file included from include/zephyr/kernel_includes.h:32:
In file included from include/zephyr/kernel_structs.h:29:
In file included from include/zephyr/arch/structs.h:29:
include/zephyr/arch/riscv/structs.h:11:1: error: empty struct has size 0
in C, size 1 in C++ [-Werror,-Wextern-c-compat]
11 | struct _cpu_arch {
| ^
In file included from include/zephyr/drivers/gpio.h:22:
In file included from include/zephyr/tracing/tracing.h:9:
In file included from include/zephyr/kernel.h:17:
In file included from include/zephyr/kernel_includes.h:36:
In file included from include/zephyr/arch/cpu.h:25:
In file included from include/zephyr/arch/riscv/arch.h:18:
include/zephyr/arch/riscv/thread.h:68:1: error: empty struct has size 0
in C, size 1 in C++ [-Werror,-Wextern-c-compat]
68 | struct _thread_arch {
| ^
Signed-off-by: Tom Hughes <tomhughes@chromium.org>
2 files changed
