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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 - Missing static function with thinlto on AArch64 when an extern function with same name exists."
href="https://bugs.llvm.org/show_bug.cgi?id=34966">34966</a>
</td>
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<th>Summary</th>
<td>Missing static function with thinlto on AArch64 when an extern function with same name exists.
</td>
</tr>
<tr>
<th>Product</th>
<td>tools
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</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>lto
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>hiraditya@msn.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>The static/internal function with thinlto gets skipped and results in a
miscompile. A reduced test case is as follows:
$cat static.c
static int __attribute__((__noinline__)) f(int i) {
volatile int j = i+10;
return j;
}
int ext() {
return f(100);
}
$ cat non-static.c
int f(void) { return 32; }
$ cat reference.c
int f();
int ext();
int main(void) {
return f()+ ext();
}
$ cat run.sh
CC=~/llvm/build/bin/clang
LARGS=~/llvm/build/lib/libLTO.dylib
LFLAGS='-fobjc-arc -Xlinker -lto_library -Xlinker'
CFLAGS='--save-temps -v -Xlinker -save-temps'
ARCH='-arch arm64 -isysroot
/Applications/Xcode_9.0.0_fb.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.0.sdk'
$CC -Oz -flto=thin static.c non-static.c reference.c $ARCH $CFLAGS $LFLAGS
$LARGS
Only one function '_f' is there and the static function 'f' is gone.
$ objdump -d a.out | grep _.*
Disassembly of section __TEXT,__text:
__text:
_ext:
_f:
_main:
However, when you target x86_64 (just remove the ARGS from command line)
$ objdump -d a.out | grep ^_.*
__text:
_ext:
_f.llvm.4247299495:
_f:
_main:</pre>
</div>
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