file include issue on functions.vh

[gxflying]

I thought it's wired that the functions.vh file was included in async_fifo_fwft.v inside the module
while all other .v file like translation_xilinx.v -> trellis.vh -> functions.vh, included in the front of the file.
AND when simulation， it will generate a error "function not decleared" when building,
ps: in my file list async_fifo_fwft.v is the first file, when move the `include "functions.vh" row to the header of the file , it's OK。
BUT, it should NOT dependent on the file position in the file list, should not it ?