<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [-cxx-abi microsoft] bad vftable for llvm::error_category"
href="http://llvm.org/bugs/show_bug.cgi?id=17382">17382</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[-cxx-abi microsoft] bad vftable for llvm::error_category
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C++
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>rnk@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>dgregor@apple.com, llvmbugs@cs.uiuc.edu, timurrrr@google.com
</td>
</tr>
<tr>
<th>Blocks</th>
<td>12477
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>This manifests as a crash in SupportTests with clang-cl /fallback.
I get a crash with a stack like:
SupportTests.exe!llvm::error_code::category() Line 767 C++
SupportTests.exe!llvm::error_category::equivalent(class llvm::error_code
const &,int) Unknown
<span class="quote">> SupportTests.exe!llvm::operator==(const llvm::error_code & _x, const llvm::error_condition & _y) Line 797 C++</span >
SupportTests.exe!llvm::operator==(const llvm::error_condition & _x, const
llvm::error_code & _y) Line 801 C++
The equivalent() method implementation was compiled by clang, and I assume the
vftable came from clang as well, but I have not confirmed this yet.
The call to equivalent() came from MSVC, and it loaded vftable offset 0x10,
which should be the (int, error_condition) overload, but instead we called
clang's implementation of the (error_condition, int) overload. MSVC seems to
think there should be one more vftable slot.
The vftable looks like this in the debugger:
- _x {_val_=22 _cat_=SupportTests.exe!0x03e2f0c8 {...} } const
llvm::error_code &
_val_ 22 int
- _cat_ SupportTests.exe!0x03e2f0c8 {...} const
llvm::error_category *
- __vfptr 0x03e1bcb0 {SupportTests.exe!const
llvm::_generic_error_category::`vftable'} {0x02815630
{SupportTests.exe!llvm::_generic_error_category::`scalar deleting
destructor'(unsigned int)}, ...} void * *
[0] 0x02815630
{SupportTests.exe!llvm::_generic_error_category::`scalar deleting
destructor'(unsigned int)} void *
[1] 0x013d6db0
{SupportTests.exe!llvm::_generic_error_category::name(void)const } void *
[2] 0x013d6c60
{SupportTests.exe!llvm::error_category::default_error_condition(int)const }
void *
[3] 0x013d6ca0
{SupportTests.exe!llvm::error_category::equivalent(int,class
llvm::error_condition const &)const } void *
[4] 0x013d6d10
{SupportTests.exe!llvm::error_category::equivalent(class llvm::error_code const
&,int)const } void *
[5] 0x013d6dd0
{SupportTests.exe!llvm::_generic_error_category::message(int)const } void *</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>