【主线待合】每次都重新编译时间戳，确保获取到的是真实的编译时间

library/common/CMakeLists.txt

@@ -8,3 +8,19 @@ if(EXISTS ${COMMON_CMAKE_PATH})
 else()
     message(FATAL_ERROR "Cannot find common build logic at ${COMMON_CMAKE_PATH}")
 endif()
+
+# 每次构建重新生成 build_time.h（custom target 永远过期），
+# 保证 common.c 因头文件内容/时间变化而重新编译，Rd_GetBuildTime() 拿到最新时间。
+set(BUILD_TIME_HEADER "${CMAKE_CURRENT_BINARY_DIR}/build_time.h")
+
+add_custom_target(GenBuildTime
+    COMMAND ${CMAKE_COMMAND}
+        "-DOUTPUT=${BUILD_TIME_HEADER}"
+        -P "${CMAKE_CURRENT_SOURCE_DIR}/cmake/gen_build_time.cmake"
+    BYPRODUCTS "${BUILD_TIME_HEADER}"
+    COMMENT "[${TARGET_NAME}] Generating build_time.h"
+    VERBATIM
+)
+
+add_dependencies(${TARGET_NAME} GenBuildTime)
+target_include_directories(${TARGET_NAME} PRIVATE "${CMAKE_CURRENT_BINARY_DIR}")

library/common/cmake/gen_build_time.cmake

@@ -0,0 +1,16 @@
+# 构建时生成 build_time.h —— 每次构建都会重新生成，内容必然变化，
+# 从而保证包含它的 common.c 必定重新编译，Rd_GetBuildTime() 返回最新构建时间。
+# 用法（由 add_custom_target 以脚本模式调用）:
+#   cmake -DOUTPUT=<path/to/build_time.h> -P gen_build_time.cmake
+
+string(TIMESTAMP RD_BUILD_TIME "%Y-%m-%d %H:%M:%S")
+
+file(WRITE "${OUTPUT}"
+    "/* Auto-generated by gen_build_time.cmake. DO NOT EDIT. */\n"
+    "#ifndef RD_BUILD_TIME_H\n"
+    "#define RD_BUILD_TIME_H\n"
+    "#define RD_BUILD_TIME \"${RD_BUILD_TIME}\"\n"
+    "#endif /* RD_BUILD_TIME_H */\n"
+)
+
+message(STATUS "[GenBuildTime] build time -> ${RD_BUILD_TIME} (${OUTPUT})")

library/common/common.c

@@ -2,6 +2,7 @@
 #include <stdarg.h>
 #include <sys/stat.h>
 #include "common.h"
+#include "build_time.h"  // 构建时生成，保证每次编译拿到最新时间
 #include <stdarg.h>  // 必须包含此头文件以使用变参宏
 
 static char g_sBuildTime[128] = {0};
@@ -98,9 +99,9 @@ int Rd_RegularFileExists(const char *_psPath)
 char *Rd_GetBuildTime(void)
 {
 #ifdef RD_HOSTNAME
-    snprintf(g_sBuildTime, sizeof(g_sBuildTime), "%s build [%s %s] by %s", RD_VERSION, __DATE__, __TIME__, RD_HOSTNAME);
+    snprintf(g_sBuildTime, sizeof(g_sBuildTime), "%s build [%s] by %s", RD_VERSION, RD_BUILD_TIME, RD_HOSTNAME);
 #else
-    snprintf(g_sBuildTime, sizeof(g_sBuildTime), "%s build [%s %s]", RD_VERSION, __DATE__, __TIME__);
+    snprintf(g_sBuildTime, sizeof(g_sBuildTime), "%s build [%s]", RD_VERSION, RD_BUILD_TIME);
 #endif
     return g_sBuildTime;
 }