How does the ndk know to include .y files

I hope this question even makes sense.

I'm trying to link an executable of 3 .c files using the android ndk make enviroment.

Some of the .c files have files with the same name except they have a .y extension (for yacc/bison example: file.c and file.y). My question is how does the ndk know when to include these .y files in the linking process. I don't have them anywh开发者_StackOverflowere in the android.mk. Also I have noticed that the ndk still looks for the .y file when I remove it from the directory.

Thanks

edit: any information you have about anything related to how the ndk works is also welcome. Thank you.