Current source factory outputs paths in @NativeHeader and @NativeLocation annotations using Path::toString [1, 2]. However, on Windows this means that backslashes in paths are not being escaped correctly, making compilation of the generated sources fail.

[1] : http://hg.openjdk.java.net/panama/dev/file/a3d7d90a369a/src/jdk.jextract/share/classes/com/sun/tools/jextract/JavaSourceFactory.java#l102
[2] : http://hg.openjdk.java.net/panama/dev/file/a3d7d90a369a/src/jdk.jextract/share/classes/com/sun/tools/jextract/JavaSourceFactory.java#l171