refactor & fix: 修复CMake找不到dl库时编译失败的问题

cmake/deps.cmake

@@ -16,6 +16,7 @@ if (WIN32 AND NOT CYGWIN)  # cygwin 不依赖 dl
         wi_install_import(TARGETS dlfcn-win32::dl)
     endif()
 else()
+    set(DLFCN_AUTO_FIND FALSE CACHE BOOL "dlfcn auto find by compiler.")
     set(DLFCN_ROOT "" CACHE STRING "The directory of dl.")
     set(dlfcn_root ${DLFCN_ROOT})
     if (dlfcn_root)
@@ -25,9 +26,13 @@ else()
     endif()
 
     if (NOT dlfcn_path)
-        set(DEPS_FOUND FALSE)
-        message(SEND_ERROR "dlfcn not found.")
-    endif()
+	if (DLFCN_AUTO_FIND)
+	    set(dlfcn_path "")
+	else()
+           set(DEPS_FOUND FALSE)
+           message(SEND_ERROR "dlfcn not found.")
+	endif() 
+   endif()
 
     unset(dlfcn_root)
     set(dlfcn_lib ${dlfcn_path})