Improve CMake SQLite3 find module

Make it compatible with official find module (CMake >= 3.14).

CMakeLists.txt

@@ -64,6 +64,9 @@ option (ENABLE_PACKAGE_CONFIG "Generate and install package config file" ON)
 option (INSTALL_PKGCONFIG_MODULE "Generate and install pkg-config module" ON)
 
 list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+if (CMAKE_VERSION VERSION_LESS 3.14)
+	list (APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/sqlite")
+endif ()
 
 #
 # Setup definitions
@@ -667,7 +670,7 @@ if (BUILD_REGTEST)
 	target_link_libraries(sndfile-regtest
 		PRIVATE
 			sndfile
-			SQLite3::SQLite3
+			SQLite::SQLite3
 			$<$<BOOL:${LIBM_REQUIRED}>:m>
 		)
 

Makefile.am

@@ -19,7 +19,7 @@ EXTRA_DIST = libsndfile.spec.in sndfile.pc.in Scripts/android-configure.sh \
 cmake_files = cmake/ClipMode.cmake cmake/FindFLAC.cmake \
 	cmake/CMakeAutoGen.cmake cmake/CMakeAutoGenScript.cmake \
 	cmake/FindOgg.cmake cmake/FindVorbis.cmake cmake/FindSndio.cmake \
-	cmake/FindSpeex.cmake cmake/FindSQLite3.cmake \
+	cmake/FindSpeex.cmake cmake/sqlite/FindSQLite3.cmake \
 	cmake/SndFileChecks.cmake cmake/TestInline.cmake \
 	cmake/TestLargeFiles.cmake cmake/TestInline.c.in \
 	cmake/FindOpus.cmake cmake/SndFileConfig.cmake.in

cmake/sqlite/FindSQLite3.cmake

@@ -0,0 +1,56 @@
+# - Find SQLite3
+# Find the native SQLite3 includes and libraries
+#
+#  SQLite3_INCLUDE_DIRS - where to find sqlite3.h, etc.
+#  SQLite3_LIBRARIES    - List of libraries when using SQLite3.
+#  SQLite3_FOUND        - True if SQLite3 found.
+
+if (SQLite3_INCLUDE_DIR)
+	# Already in cache, be silent
+	set (SQLite3_FIND_QUIETLY TRUE)
+endif ()
+
+find_package (PkgConfig QUIET)
+pkg_check_modules (PC_SQLite3 QUIET sqlite3)
+
+set (SQLite3_VERSION ${PC_SQLite3_VERSION})
+
+find_path (SQLite3_INCLUDE_DIR sqlite3.h
+	HINTS
+		${PC_SQLite3_INCLUDEDIR}
+		${PC_SQLite3_INCLUDE_DIRS}
+		${SQLite3_ROOT}
+	)
+
+find_library (SQLite3_LIBRARY
+	NAMES
+		sqlite3
+	HINTS
+		${PC_SQLite3_LIBDIR}
+		${PC_SQLite3_LIBRARY_DIRS}
+		${SQLite3_ROOT}
+	)
+
+include (FindPackageHandleStandardArgs)
+
+find_package_handle_standard_args (SQLite3
+	REQUIRED_VARS
+		SQLite3_LIBRARY
+		SQLite3_INCLUDE_DIR
+	VERSION_VAR
+		SQLite3_VERSION
+	)
+
+if (SQLite3_FOUND)
+	set SQLite3_INCLUDE_DIRS ${SQLite3_INCLUDE_DIR})
+	set SQLite3_LIBRARIES ${SQLite3_LIBRARY})
+	if (NOT TARGET SQLite::SQLite3)
+		add_library (SQLite::SQLite3 UNKNOWN IMPORTED)
+		set_target_properties (SQLite::SQLite3 PROPERTIES
+			INTERFACE_INCLUDE_DIRECTORIES "${SQLite3_INCLUDE_DIRS}"
+			IMPORTED_LOCATION "${SQLite3_LIBRARIES}"
+		)
+	endif ()
+endif ()
+
+mark_as_advanced (SQLite3_INCLUDE_DIR SQLite3_LIBRARY)