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From: Khem Raj <raj.khem@gmail.com>
To: bitbake-devel@lists.openembedded.org
Subject: Re: when does ${XX} in variable names get expanded?
Date: Thu, 04 Aug 2011 08:30:28 -0700	[thread overview]
Message-ID: <4E3ABB14.1040203@gmail.com> (raw)
In-Reply-To: <C10D3FB0CD45994C8A51FEC1227CE22F2CE2E480D0@shsmsx502.ccr.corp.intel.com>

On 08/04/2011 02:19 AM, Lu, Lianhao wrote:
> Hi guys,
>
> For the following variable definition in bitbake,
>
> VVV = "llu"
> A_${VVV} = "VVV"
> A_llu = "llu"
>
> B = "${@bb.data.getVar('A_llu', d, True)}"
> C := "${@bb.data.getVar('A_llu', d, True)}"
>
> Why B is "VVV" and C is "llu" in final? I'm wondering when is the ${VVV} in the variable name of A_${VVV} expanded.
>

:= demands immediate expansion so any variables thats in the expression 
will be evaluated right there

where as = will be evaluated on reference and the variables it uses will 
be read/evaluated at that time.

> Best Regards,
> -Lianhao Lu
>
> _______________________________________________
> bitbake-devel mailing list
> bitbake-devel@lists.openembedded.org
> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/bitbake-devel




      parent reply	other threads:[~2011-08-04 15:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-04  9:19 when does ${XX} in variable names get expanded? Lu, Lianhao
2011-08-04  9:48 ` Richard Purdie
2011-08-04 15:30 ` Khem Raj [this message]

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