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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 - DEFINED(foo) always evaluates to true if foo is also defined in the script"
href="https://bugs.llvm.org/show_bug.cgi?id=40396">40396</a>
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<th>Summary</th>
<td>DEFINED(foo) always evaluates to true if foo is also defined in the script
</td>
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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>All
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>ELF
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
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<th>Reporter</th>
<td>pkmx.tw@gmail.com
</td>
</tr>
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org, peter.smith@linaro.org
</td>
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<p>
<div>
<pre>$ cat test.ld
SECTIONS {
foo = DEFINED(foo) ? foo : 0x1000;
ASSERT ( foo == 0x1000 , "should not happen" )
}
$ echo | clang -xc - -c -o empty.o
$ ld.lld empty.o -Ttest.ld
ld.lld: error: should not happen
This is a documented usage in bfd's ld manual
(<a href="https://sourceware.org/binutils/docs/ld/Builtin-Functions.html#Builtin-Functions">https://sourceware.org/binutils/docs/ld/Builtin-Functions.html#Builtin-Functions</a>),
where foo should retain its value if it is already set prior to the statement
(via --defsym or other methods), or otherwise set to a default value 0x1000.
However, lld always evaluates it to 0.
The root cause seems to be rL323729 that adds all symbol assignments to the
symbol table as a dummy `Defined` absolute symbol of value 0, which causes the
DEFINED() builtin to always evaluate to true.</pre>
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