[Bug] RISC-V RT-Smart：使用 Newlib 工具链编译 vDSO 时 CLOCK_* 常量未定义 #12025

RT-Thread Version

RT-Thread 5.4.0，分支 issue_3 Commit: f50c9bf

Affected area

RT-Smart

Hardware/BSP vendor

Not applicable / Other

Architecture

RISC-V

Board and hardware details

BSP：bsp/qemu-virt64-riscv 运行平台：QEMU virt，RV64，S-mode 启用 RT_USING_SMART、RT_USING_CLOCK_TIME 和 RT_USING_VDSO。 问题发生于编译阶段，尚未进入 QEMU 运行阶段。

Develop Toolchain

GCC

Describe the bug

在 qemu-virt64-riscv BSP 中启用 RT-Smart 和 vDSO 后，使用基于 Newlib 的 RISC-V GCC 工具链编译，vDSO 用户态源码因多个 CLOCK_* 常量未定义而编译失败。

开发环境

• 工具链：SiFive GCC-Metal 10.2.0-2020.12.8
• 编译器：riscv64-unknown-elf-gcc 10.2.0
• C 库：Newlib 4.1.0
• BSP：bsp/qemu-virt64-riscv

复现步骤

1. 配置 RTT_EXEC_PATH，指向上述工具链的实际 bin 目录。
2. 设置工具链前缀：

   export RTT_CC_PREFIX=riscv64-unknown-elf-

3. 在 bsp/qemu-virt64-riscv 目录运行 scons --menuconfig，确保启用：

   CONFIG_RT_USING_SMART=y
   CONFIG_RT_USING_CLOCK_TIME=y
   CONFIG_RT_USING_POSIX_CLOCK=y
   CONFIG_RT_USING_VDSO=y
   

4. 保存配置并编译：

   scons -j8

实际结果

以下为完整报错：
(base) tengzijun@tengzijun-virtual-machine:~/rt-thread/bsp/qemu-virt64-riscv$ scons -j8
scons: Reading SConscript files ...
scons: Entering directory `/home/tengzijun/rt-thread/components/lwp/vdso/user'
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
riscv64-unknown-elf-gcc -o build/risc-v/vdso_clock_gettime.os -c -mcmodel=medany -march=rv64imafdc -mabi=lp64 -Wall -Wextra -Wno-unused-parameter -Wno-cpp -std=gnu99 -O2 -fPIC -ffreestanding -fno-builtin -fvisibility=hidden -nostdlib -nostartfiles -fPIC -I. -Icommon -Iarch/risc-v -I/home/tengzijun/rt-thread/components/lwp/vdso common/vdso_clock_gettime.c
common/vdso_clock_gettime.c: In function 'rt_vdso_resolve_clock_index':
common/vdso_clock_gettime.c:17:10: error: 'CLOCK_REALTIME_COARSE' undeclared (first use in this function); did you mean 'CLOCK_REALTIME'?
17 | case CLOCK_REALTIME_COARSE:
| ^~~~~~~~~~~~~~~~~~~~~
| CLOCK_REALTIME
common/vdso_clock_gettime.c:17:10: note: each undeclared identifier is reported only once for each function it appears in
common/vdso_clock_gettime.c:21:10: error: 'CLOCK_MONOTONIC' undeclared (first use in this function)
21 | case CLOCK_MONOTONIC:
| ^~~~~~~~~~~~~~~
common/vdso_clock_gettime.c:22:10: error: 'CLOCK_MONOTONIC_COARSE' undeclared (first use in this function)
22 | case CLOCK_MONOTONIC_COARSE:
| ^~~~~~~~~~~~~~~~~~~~~~
common/vdso_clock_gettime.c:23:10: error: 'CLOCK_MONOTONIC_RAW' undeclared (first use in this function)
23 | case CLOCK_MONOTONIC_RAW:
| ^~~~~~~~~~~~~~~~~~~
common/vdso_clock_gettime.c:24:10: error: 'CLOCK_BOOTTIME' undeclared (first use in this function); did you mean 'CLOCK_REALTIME'?
24 | case CLOCK_BOOTTIME:
| ^~~~~~~~~~~~~~
| CLOCK_REALTIME
scons: *** [build/risc-v/vdso_clock_gettime.os] Error 1
scons: building terminated because of errors.
exec command: "scons -C /home/tengzijun/rt-thread/components/lwp/vdso/user RTT_VDSO_ARCH=risc-v" failed.

Other additional context

初步排查发现：

• vDSO 用户态代码通过 vdso_user_internal.h 包含工具链的 <time.h>。
• 当前工具链中，部分 CLOCK_* 定义受 __GNU_VISIBLE 或 _POSIX_MONOTONIC_CLOCK 等条件控制。
• 按当前 vDSO 编译条件预处理 <time.h>，上述报错涉及的常量没有暴露。
• 初步怀疑与 vDSO 构建配置和 Newlib 头文件兼容性有关，尚未确认最终修复方式。