Re: absolute or relative path for source files

[Daniel Herring]

On Sun, 15 May 2011, Vincent Torri wrote:

> in a Makefile.am that is in the "$(top_builddir)/path1/path3" directory, the
> library uses a file that is in the "$(top_builddir)/path1/path2" directory.
> Is it better to use absolute path:
>
> mylib_SOURCES = $(top_builddir)/path1/path2/file.c
>
> or relative path
>
> mylib_SOURCES = ../path2/file.c
>
> ?

Technically, both are relative (and defined by autoconf IIRC).  Use 
abs_top_builddir for an absolute path.  Note that builddir should only be 
used to point to sources actually created by the build (srcdir for the 
others).

Not sure what the official story is.  I treat these as any other 
absolute/relative path issue.  Absolute paths break if the target moves, 
relative paths break if either target moves relative to the other.  I 
generally prefer the shorter form, also preferring absolute paths if they 
appear in several directories.

The variable dereference can also be preferrable when including another 
makefile; it prevents automake from doing the include early.

- Daniel