Fix build issue when no platform has been set

3rdParty/libarchive/ext/CMakeLists.txt

@@ -68,7 +68,7 @@ ExternalProject_Add(lz4
                     -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_BINARY_DIR}/INSTALL
         )
 
-if (${PLATFORM} STREQUAL "OS64" OR ${PLATFORM} STREQUAL "OS64COMBINED")
+if ("${PLATFORM}" STREQUAL "OS64" OR "${PLATFORM}" STREQUAL "OS64COMBINED")
     set(EXTRA_ARGS -DHAVE__FSEEKI64:BOOL=OFF -DHAVE_FUTIMESAT:BOOL=OFF)
 endif()
 

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.28 FATAL_ERROR)
 
-if (${PLATFORM} STREQUAL "OS64" OR ${PLATFORM} STREQUAL "OS64COMBINED")
+if ("${PLATFORM}" STREQUAL "OS64" OR "${PLATFORM}" STREQUAL "OS64COMBINED")
     set(ENABLE_ARC OFF)
     set(DEPLOYMENT_TARGET "14.0")
     set(CMAKE_TOOLCHAIN_FILE "${CMAKE_SOURCE_DIR}/cmake/toolchain/ios.toolchain.cmake")