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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - missing error on reference to undefined weak symbol"
href="https://bugs.llvm.org/show_bug.cgi?id=34058">34058</a>
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<th>Summary</th>
<td>missing error on reference to undefined weak symbol
</td>
</tr>
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<th>Product</th>
<td>lld
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>ELF
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
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<th>Reporter</th>
<td>rafael.espindola@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>bfd ld with -shared will produce an error on
leaq foo(%rip), %rax
.weak foo
.hidden foo
That is reasonable. The value of foo is zero, and we will not be able to
compute that a runtime. The intention of the leaq was probably to check the
value of foo in the first place.
The problem is that it should *not* produce an error if the leaq is replaced
with a call. The logic being that the call will be guarded:
if (foo)
foo();
Unfortunately, on x86_64 at least, both constructs produce the same relocation.
It just seems too fuzzy to have the linker parse the instruction using the
relocation.
I am reporting the bug in case someone has a better idea on how to implement
this or if some other architecture does have different relocations.</pre>
</div>
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