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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - wrong code generated for extern_weak relocation with -pic-level 2 -pic-is-pie -mpie-copy-relocations"
href="https://bugs.llvm.org/show_bug.cgi?id=34148">34148</a>
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<th>Summary</th>
<td>wrong code generated for extern_weak relocation with -pic-level 2 -pic-is-pie -mpie-copy-relocations
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<th>Product</th>
<td>libraries
</td>
</tr>
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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
</td>
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<th>Component</th>
<td>Backend: X86
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>richard-llvm@metafoo.co.uk
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</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<p>
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<pre>Testcase:
extern "C" int printf(const char*, ...);
extern __attribute__((weak)) int n;
int main() { printf("%p\n", &n); }
Built with -pic-level 2 -pic-is-pie -mpie-copy-relocations, we generate this
bogus code:
leaq .L.str(%rip), %rdi
leaq n(%rip), %rsi
xorl %eax, %eax
callq printf@PLT
Note the %rip-relative lea for n: this is wrong, that relocation type cannot
represent the possibility that &n is 0, which happens when the symbol is not
defined.</pre>
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