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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 - target-features are not preserved in LTO object files that contain no functions"
href="https://bugs.llvm.org/show_bug.cgi?id=52338">52338</a>
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<th>Summary</th>
<td>target-features are not preserved in LTO object files that contain no functions
</td>
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<th>Product</th>
<td>libraries
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Backend: WebAssembly
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>sbc@chromium.org
</td>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>LLVM target features are attached to functions, so if there are no functions in
a given TU then the resulting LTO object file will not include any
target-features.
For native object files problem does not occurs.
The problem arrises, for example, in emscripten when one does
```
$ emcc -s SIDE_MODULE -O2 -fPIC empty.c
wasm-ld: error: mutable global imported but 'mutable-globals' feature not
present in inputs: `__stack_pointer`. Use --no-check-features to suppress.
```
This is because clang injects the mutable-globals features when
`RelocationModel == llvm::Reloc::PIC_`, but when there is no function in the
object file this information is lost, and then when the LTO/bitcode object is
compiled it lacks this feature.</pre>
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</p>
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