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Re: [Xen-devel] [PATCH 1/9] golang/xenlight: Don't try to marshall zero-length arrays


  • To: <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: George Dunlap <george.dunlap@xxxxxxxxxx>
  • Date: Fri, 27 Dec 2019 16:36:10 +0000
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  • Cc: Nick Rosbrook <rosbrookn@xxxxxxxxxxxx>
  • Delivery-date: Fri, 27 Dec 2019 16:36:34 +0000
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On 12/27/19 4:32 PM, George Dunlap wrote:
> The current fromC array code will do the "magic" casting and
> martialling even when num_foo variable is 0.  Go crashes when doing
> the cast.
> 
> Furthermore, the current toC array code will convert a nil slice into
> a zero-length malloc.  The resulting pointer is non-NULL, and confuses
> libxl.
> 
> Only do array marshalling if the number of elements is non-zero;
> otherwise, leave the target pointer empty (nil for Go slices, NULL for
> C arrays).
> 
> The toC half of this should be folded into "golang/xenlight:
> implement array Go to C marshaling".
> 
> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxx>

The .go program I used to test this series is attached, to give you an
idea what the current iteration looks like, and potentially give it a spin.

 -George

Attachment: xltest.go
Description: Text Data

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