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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - LLD leaves empty sections in header size calculation"
href="https://bugs.llvm.org/show_bug.cgi?id=40381">40381</a>
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<th>Summary</th>
<td>LLD leaves empty sections in header size calculation
</td>
</tr>
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<th>Product</th>
<td>lld
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>COFF
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>rpjohnst@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>When linking a PE image with empty sections, space for their section headers is
included in the size of the output headers, while the sections themselves are
removed.
For example, building this C file:
int __stdcall mainCRTStartup(void) { return 0; }
with this invocation:
clang-cl /Zl compiler.c -fuse-ld=lld /link /subsystem:console
/entry:mainCRTStartup
produces an image with SizeOfHeaders set to 0x400, but only a single section
(.text). The equivalent invocation of cl/link produces an image with
SizeOfHeaders set to 0x200:
cl /Zl compiler.c /link /subsystem:console /entry:mainCRTStartup
/novcfeature /nocoffgrpinfo
This happens because of the dependence between Writer::assignAddresses and
Writer::removeEmptySections, in lld/COFF/Writer.cpp- section sizes (and thus
emptiness) are computed at the same time as the header size, before empty
sections are removed.</pre>
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</p>
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