cmake: allow disabling `RANDOM_FILE`

`./configure` allows `--random-file=no`. Allow this with CMake too,
using `-DRANDOM_FILE=OFF` (other boolean values work too: no, false, 0,
case insensitive.)

Also disable `RANDOM_FILE` detection for Windows.

Closes #14743

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0c17f37880b78e65f27cb9fd82d0648b6ea7eb1d..4e846abd4ae8dc0d1e7749d7afb49bde8078a701 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1430,7 +1430,8 @@ if(SIZEOF_SUSECONDS_T)
   set(HAVE_SUSECONDS_T 1)
 endif()
 
-if(NOT CMAKE_CROSSCOMPILING)
+if(NOT WIN32 AND NOT CMAKE_CROSSCOMPILING AND
+   (NOT DEFINED RANDOM_FILE OR RANDOM_FILE))
   find_file(RANDOM_FILE "urandom" "/dev")
   mark_as_advanced(RANDOM_FILE)
 endif()