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<a href="https://gitlab.com/stweil">Stefan Weil</a>
<a href="https://gitlab.com/gnutls/libtasn1/-/merge_requests/71#note_500125146">commented</a>:
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<p dir="auto">Code constructs like (NULL + offset) are undefined, so clang may handle that as NULL and ignore the offset. This can also be a security feature to avoid illegal memory access. Try this test program with <code>-O2</code>:</p>
<pre class="code highlight js-syntax-highlight plaintext" lang="plaintext" v-pre="true"><code><span id="LC1" class="line" lang="plaintext">#include <stdio.h></span>
<span id="LC2" class="line" lang="plaintext"></span>
<span id="LC3" class="line" lang="plaintext">static void f(int offset, const void *p) {</span>
<span id="LC4" class="line" lang="plaintext"> if (p != NULL) {</span>
<span id="LC5" class="line" lang="plaintext"> printf("NULL+%d => %p\n", offset, p + offset);</span>
<span id="LC6" class="line" lang="plaintext"> } else {</span>
<span id="LC7" class="line" lang="plaintext"> printf("NULL+%d => NULL\n", offset);</span>
<span id="LC8" class="line" lang="plaintext"> }</span>
<span id="LC9" class="line" lang="plaintext">}</span>
<span id="LC10" class="line" lang="plaintext"></span>
<span id="LC11" class="line" lang="plaintext">int main(int argc, char *argv[]) {</span>
<span id="LC12" class="line" lang="plaintext"> void *p = NULL;</span>
<span id="LC13" class="line" lang="plaintext"> f(argc, p);</span>
<span id="LC14" class="line" lang="plaintext"> return 0;</span>
<span id="LC15" class="line" lang="plaintext">}</span></code></pre>
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