Use FetchContent to get Windows bison dependency at configure time

Author: LegalizeAdulthood

parsedate/CMakeLists.txt

@@ -1,3 +1,13 @@
+if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+    include(FetchContent)
+    FetchContent_Declare(download_bison
+        URL "http://user.xmission.com/~legalize/trn/bison-2.4.1.zip"
+        URL_MD5 "6d728df45f1cf60f5569da4963322ec3"
+        DOWNLOAD_EXTRACT_TIMESTAMP FALSE)
+    FetchContent_MakeAvailable(download_bison)
+    set(BISON_ROOT "${download_bison_SOURCE_DIR}/bin")
+    message(STATUS "BISON_ROOT=${BISON_ROOT}")
+endif()
 find_package(BISON REQUIRED)
 
 bison_target(parsedate parsedate.y ${CMAKE_CURRENT_BINARY_DIR}/parsedate.c)