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Re: [PATCH 1/9] Define a structure for object IDs.

From
Johannes Sixt <j6t@kdbg.org>
Date
May 4, 2014, 09:21 UTC
Message-ID
<536606AB.1020803@kdbg.org>
In-Reply-To
<5365D91E.70207@alum.mit.edu>
Am 04.05.2014 08:07, schrieb Michael Haggerty:
Show 10 quoted lines
> On 05/03/2014 10:12 PM, brian m. carlson wrote:
>> Introduce a structure for object IDs.  This allows us to obtain the benefits
>> of compile-time checking for misuse.  The structure is expected to remain
>> the same size and have the same alignment requirements on all known
>> platforms, compared to the array of unsigned char.
>
> Please clarify whether you plan to rely on all platforms having "the
> same size and alignment constraints" for correctness, or whether that
> observation of the status quo is only meant to reassure us that this
> change won't cause memory to be wasted on padding.

I think that a compiler that has different size and alignment requirements for the proposed struct object_id and an unsigned char[20] would, strictly speaking, not be a "C" compiler.

-- Hannes
Previous: Michael HaggertyNext: David Kastrup
Message 4 of 39 in “Use a structure for object IDs.”
  1. 0/9 Use a structure for object IDs.brian m. carlson, May 3, 2014
  2. 1/9 Define a structure for object IDs.brian m. carlson, May 3, 2014
  3. Michael HaggertyMay 4, 2014
  4. Johannes SixtMay 4, 2014
  5. David KastrupMay 4, 2014
  6. Andreas SchwabMay 4, 2014
  7. Johannes SixtMay 4, 2014
  8. Andreas SchwabMay 4, 2014
  9. David KastrupMay 5, 2014
  10. Andreas SchwabMay 5, 2014
  11. James DenholmMay 5, 2014
  12. David KastrupMay 5, 2014
  13. Michael HaggertyMay 5, 2014
  14. Andreas SchwabMay 5, 2014
  15. David KastrupMay 5, 2014
  16. Felipe ContrerasMay 5, 2014
  17. Duy NguyenMay 4, 2014
  18. brian m. carlsonMay 4, 2014
  19. Andreas SchwabMay 4, 2014
  20. David KastrupMay 4, 2014
  21. Andreas SchwabMay 4, 2014
  22. David KastrupMay 4, 2014
  23. Andreas SchwabMay 4, 2014
  24. 2/9 bisect.c: convert to use struct object_idbrian m. carlson, May 3, 2014
  25. 3/9 archive.c: convert to use struct object_idbrian m. carlson, May 3, 2014
  26. 4/9 zip: use GIT_OID_HEXSZ for trailersbrian m. carlson, May 3, 2014
  27. 5/9 branch.c: convert to use struct object_idbrian m. carlson, May 3, 2014
  28. 6/9 bulk-checkin.c: convert to use struct object_idbrian m. carlson, May 3, 2014
  29. 7/9 bundle.c: convert leaf functions to struct object_idbrian m. carlson, May 3, 2014
  30. Michael HaggertyMay 6, 2014
  31. 8/9 cache-tree: convert struct cache_tree to use object_idbrian m. carlson, May 3, 2014
  32. Michael HaggertyMay 6, 2014
  33. Michael HaggertyMay 6, 2014
  34. 9/9 diff: convert struct combine_diff_path to object_idbrian m. carlson, May 3, 2014
  35. Michael HaggertyMay 6, 2014
  36. brian m. carlsonMay 3, 2014
  37. Michael HaggertyMay 4, 2014
  38. Johannes SixtMay 4, 2014
  39. brian m. carlsonMay 4, 2014

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