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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [Miscompilation] Inlining Causes Jump to Wrong Address, Maybe Because of setjmp()"
href="https://bugs.llvm.org/show_bug.cgi?id=50917">50917</a>
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<th>Summary</th>
<td>[Miscompilation] Inlining Causes Jump to Wrong Address, Maybe Because of setjmp()
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>12.0
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>normal
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>gavin.d.howard@gmail.com
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<pre>Clang is inlining a function, and when returning from the function, it is
jumping to the wrong location.
The code in question is at
<a href="https://git.yzena.com/gavin/bc/src/commit/c2d2977f2c6c9fe3cd8dc9b07fc8913008c81895/src/vm.c#L780-L842">https://git.yzena.com/gavin/bc/src/commit/c2d2977f2c6c9fe3cd8dc9b07fc8913008c81895/src/vm.c#L780-L842</a>
.
As near as I can tell, when the call to `bc_vm_readLine()` returns `false`, the
code then does not jump to the end of the loop. Instead, it jumps to line 815,
which previously did a `setjmp()`. That `setjmp()` then thinks that a
`longjmp()` happens, which causes it to jump past the end of the loop and to
the `err:` label (the code inside `BC_SETJMP_LOCKED(err)` essentially does a
`if (setjmp(buf)) goto err;`).
I have confirmed the bug exists in Clang 12.0.1-rc3, 11.1.0, 10.0.1, and 9.0.1.
I could not get 8.0.1 to compile.</pre>
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