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<p>Hi Rémi,</p>
<p>On 2017-02-20 18:45, Rémi Denis-Courmont wrote:</p>
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<pre><code> Le maanantaina 20. helmikuuta 2017, 15.06.59 EET Filip Roséen a écrit :</code></pre>
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<pre><code> If a compiler introduce padding between the members of struct
xa_header, the previous way of interpreting the incoming stream will
yield unexpected behavior.</code></pre>
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<pre><code> I do not see how a comforming C compiler could introduce padding anywhere
except at the end of the structure - since all types are aligned on their
natural boundary.</code></pre>
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<p>There is nothing to prevent a comforming compiler to not introduce padding even though the relevant <em>data-members</em> are aligned to their natural boundary. At least I have not stumbled across any such guarantee when spending time with the ISO C Standards (I would however be happy to be corrected).</p>
<p>The guarantees related to padding within a <code>struct</code> are available in <code>6.7.2.1/15</code> of <code>N1570</code> (the contents is the same for the official ISO document (which I cannot remember the <em>N-number</em> for at the top of my head).</p>
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<pre><code> (So yes, there is a bug, but the fix should be much more trivial.)</code></pre>
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<p>I think the current fix is trivial enough, especially given what was stated in the previous section.</p>
<p>Best Regards,<br />
Filip</p>
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