question about FILE_DIRNAME versus THISDIR when setting FILESPATH

question about FILE_DIRNAME versus THISDIR when setting FILESPATH

[Robert P. J. Day]

  probably a simple answer to this, but in examining the way FILESPATH
is created, i notice that, in .bb recipe files, the general form of
setting FILESPATH always seems to involve the use of the FILE_DIRNAME
variable, such as in the default value from base.bbclass:

FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}",
"${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}"

  however, when one is extending FILESPATH in .bbappend files, the
variable used to refer to the current directory is always THISDIR. but
it's not clear what the distinction is.

  i'm using "bb show" and, when i'm referring to the value of
FILESPATH for an overlayed recipe, both FILE_DIRNAME and THISDIR seem
to properly refer to the directory for the bbappend file.

  can someone clarify the proper usage of these variables? in
particular, why it's important for .bb files to use FILE_DIRNAME but
.bbappend files to use THISDIR? thanks.

rday

p.s.  i'll have a more involved FILESPATH question shortly.

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: question about FILE_DIRNAME versus THISDIR when setting FILESPATH

[Paul Eggleton]

Hi Robert,

On Sunday 10 November 2013 13:02:32 Robert P. J. Day wrote:
>   probably a simple answer to this, but in examining the way FILESPATH
> is created, i notice that, in .bb recipe files, the general form of
> setting FILESPATH always seems to involve the use of the FILE_DIRNAME
> variable, such as in the default value from base.bbclass:
> 
> FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}",
> "${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}"
> 
>   however, when one is extending FILESPATH in .bbappend files, the
> variable used to refer to the current directory is always THISDIR. but
> it's not clear what the distinction is.
> 
>   i'm using "bb show" and, when i'm referring to the value of
> FILESPATH for an overlayed recipe, both FILE_DIRNAME and THISDIR seem
> to properly refer to the directory for the bbappend file.
> 
>   can someone clarify the proper usage of these variables? in
> particular, why it's important for .bb files to use FILE_DIRNAME but
> .bbappend files to use THISDIR? thanks.

These variables are set in pretty much the same way; the only difference is 
that FILE_DIRNAME doesn't expand FILE before running it through 
os.path.dirname(); I'm not sure if that is deliberate or not. In practice I 
doubt it makes any difference since FILE is set to a full path by BitBake, 
although as you note a convention has been established of using THISDIR in 
bbappends and FILE_DIRNAME elsewhere.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre