Reworked the CMake script to only use download when necessary.

Added a cache of known Qt5 versions and their SQLite private headers/sources.
Added a script for generating this cache easily.

Author: blizzard4591

CMakeLists.txt

@@ -42,36 +42,45 @@ endif()
 
 if (Qt5Sql_FOUND)
 	message(STATUS "Found Qt5 version ${Qt5Sql_VERSION}.")
-	if (Qt5Sql_VERSION VERSION_LESS 5.8.0)
-		set(DOWNLOAD_PATH "src/sql/drivers/sqlite")
+	
+	set(_PRIVATE_SOURCES_DIRECTORY "")
+	if (EXISTS "${PROJECT_SOURCE_DIR}/qt-file-cache/${Qt5Sql_VERSION}")
+		message(STATUS "Using cached/shipped versions of required header/source files.")
+		set(_PRIVATE_SOURCES_DIRECTORY "${PROJECT_SOURCE_DIR}/qt-file-cache/${Qt5Sql_VERSION}")
+		include_directories("${PROJECT_SOURCE_DIR}/qt-file-cache/${Qt5Sql_VERSION}")
 	else()
-		set(DOWNLOAD_PATH "src/plugins/sqldrivers/sqlite")
-	endif()
-
-	set(URL_HEADER "https://raw.githubusercontent.com/qt/qtbase/v${Qt5Sql_VERSION}/${DOWNLOAD_PATH}/qsql_sqlite_p.h")
-	set(URL_CPP "https://raw.githubusercontent.com/qt/qtbase/v${Qt5Sql_VERSION}/${DOWNLOAD_PATH}/qsql_sqlite.cpp")
-	message(STATUS "URL = ${URL_HEADER}")
-
-	file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}/qt-private")
-	include_directories("${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}")
-
-	file(DOWNLOAD "${URL_HEADER}" "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}/qt-private/qsql_sqlite_p.h" STATUS STATUS_HEADER_LIST TLS_VERIFY on LOG LOG_HEADER)
-	file(DOWNLOAD "${URL_CPP}" "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}/qt-private/qsql_sqlite.cpp" STATUS STATUS_CPP_LIST TLS_VERIFY on LOG LOG_CPP)
-
-	list(GET STATUS_HEADER_LIST 0 STATUS_HEADER)
-	list(GET STATUS_CPP_LIST 0 STATUS_CPP)
-	if ((NOT "${STATUS_HEADER}" STREQUAL "0") OR (NOT "${STATUS_CPP}" STREQUAL "0"))
-		list(GET STATUS_HEADER_LIST 1 STATUS_HEADER_ERROR)
-		list(GET STATUS_CPP_LIST 1 STATUS_CPP_ERROR)
-		message(SEND_ERROR "Could not download required Qt5 private header/source files. Please report this error! Qt Version: ${Qt5Sql_VERSION}. Result Header: ${STATUS_HEADER}. Error: ${STATUS_HEADER_ERROR}. Result Source: ${STATUS_CPP}. Error: ${STATUS_CPP_ERROR}. Log Header: ${LOG_HEADER}. Log Source: ${LOG_CPP}.")
-	else()
-		message(STATUS "Downloaded required header/source files for your Qt5 version.")
+		if (Qt5Sql_VERSION VERSION_LESS 5.8.0)
+			set(DOWNLOAD_PATH "src/sql/drivers/sqlite")
+		else()
+			set(DOWNLOAD_PATH "src/plugins/sqldrivers/sqlite")
+		endif()
+
+		set(URL_HEADER "https://raw.githubusercontent.com/qt/qtbase/v${Qt5Sql_VERSION}/${DOWNLOAD_PATH}/qsql_sqlite_p.h")
+		set(URL_CPP "https://raw.githubusercontent.com/qt/qtbase/v${Qt5Sql_VERSION}/${DOWNLOAD_PATH}/qsql_sqlite.cpp")
+		message(STATUS "URL = ${URL_HEADER}")
+
+		file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}")
+		set(_PRIVATE_SOURCES_DIRECTORY "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}")
+		include_directories("${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}")
+
+		file(DOWNLOAD "${URL_HEADER}" "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}/qsql_sqlite_p.h" STATUS STATUS_HEADER_LIST TLS_VERIFY on LOG LOG_HEADER)
+		file(DOWNLOAD "${URL_CPP}" "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}/qsql_sqlite.cpp" STATUS STATUS_CPP_LIST TLS_VERIFY on LOG LOG_CPP)
+
+		list(GET STATUS_HEADER_LIST 0 STATUS_HEADER)
+		list(GET STATUS_CPP_LIST 0 STATUS_CPP)
+		if ((NOT "${STATUS_HEADER}" STREQUAL "0") OR (NOT "${STATUS_CPP}" STREQUAL "0"))
+			list(GET STATUS_HEADER_LIST 1 STATUS_HEADER_ERROR)
+			list(GET STATUS_CPP_LIST 1 STATUS_CPP_ERROR)
+			message(SEND_ERROR "Could not download required Qt5 private header/source files. Please report this error! Qt Version: ${Qt5Sql_VERSION}. Result Header: ${STATUS_HEADER}. Error: ${STATUS_HEADER_ERROR}. Result Source: ${STATUS_CPP}. Error: ${STATUS_CPP_ERROR}. Log Header: ${LOG_HEADER}. Log Source: ${LOG_CPP}.")
+		else()
+			message(STATUS "Downloaded required header/source files for your Qt5 version.")
+		endif()
 	endif()
 endif()
 
 add_library(qsqlcipher ${LIBTYPE}
     smain.cpp
-    "${CMAKE_BINARY_DIR}/qt-private-from-git-version-${Qt5Sql_VERSION}/qt-private/qsql_sqlite.cpp"
+    "${_PRIVATE_SOURCES_DIRECTORY}/qsql_sqlite.cpp"
 )
 
 if (WIN32)