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<base href="https://llvm.org/bugs/" />
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [WinEH] bad codegen when calling printf in catch and building with optimizations"
href="https://llvm.org/bugs/show_bug.cgi?id=26036">26036</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[WinEH] bad codegen when calling printf in catch and building with optimizations
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</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>-New Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>r.sagitario@gmx.de
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>#include <stdio.h>
int main(int argc, char** argv)
{
try
{
throw int(8);
}
catch (int o)
{
printf("caught\n");
}
return 0;
}
Compiling this with "clang -m32 -fexceptions -O" creates a crashing executable.
This is caused by the LibCallSimplifier pass replacing printf with puts, but
dropping the "funclet" token:
[...]
catch.dispatch.i: ; preds = %entry
%2 = catchswitch within none [label %catch.i] unwind to caller
catch.i: ; preds = %catch.dispatch.i
%3 = catchpad within %2 [%rtti.TypeDescriptor2* @"\01??_R0H@8", i32 0, i32*
%o.i]
%puts.i = call i32 @puts(i8* nonnull getelementptr inbounds ([7 x i8], [7 x
i8]* @str, i32 0, i32 0))
catchret from %3 to label %"\01?test56@@YAXXZ.exit"
[...]
This generates an incomplete funclet for the catch:
"?catch$2@?0??main@@YAXXZ@4HA":
LBB1_2: # %catch
pushl %ebp
subl $8, %esp
addl $12, %ebp
movl %esp, -28(%ebp)
Lfunc_end0:
You can disable replacements by setting the NoBuiltin attribute on the printf
function call, but that's not ideal.</pre>
</div>
</p>
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