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<base href="http://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 --- - enabling debuginfo with -g causes an undefined reference error at link time"
href="http://llvm.org/bugs/show_bug.cgi?id=19341">19341</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>enabling debuginfo with -g causes an undefined reference error at link time
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</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>DebugInfo
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>greg_bedwell@sn.scee.net
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>The testcase below links correctly when built without -g specified, but fails
with undefined reference errors with -g:
$ clang -v
clang version 3.5.0 (205622)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.6.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.2
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Candidate multilib: .;@m64
Selected multilib: .;@m64
$ clang 1.cpp
$ clang 1.cpp -g
/tmp/1-812f49.o:(.debug_info+0x91): undefined reference to `Bravo::charlie'
/tmp/1-812f49.o:(.debug_info+0xf2): undefined reference to `alpha()'
clang-3.5: error: linker command failed with exit code 1 (use -v to see
invocation)
// ==========================================
extern char alpha();
struct Bravo {
static int charlie;
};
template <char (*delta)()> struct Echo {
int foxtrot() {
return 1;
};
};
template <> struct Echo<alpha> {
int foxtrot() {
return 100;
};
};
template <int *delta> struct Golf {
int foxtrot() {
return 1000;
};
};
template <> struct Golf<&Bravo::charlie> {
int foxtrot() {
return 10000;
};
};
int main() {
Echo<alpha> hotel;
Golf<&Bravo::charlie> india;
return hotel.foxtrot() + india.foxtrot();
}
// ==========================================
I've bisected the error and can see that the testcase links successfully at
r181631, but with r181634 it fails with an undefined reference to
'Bravo::charlie'. At r181685 we also start seeing the undefined reference to
'alpha()'.
Here are the relevant revisions:
-----------------------------------------------
<a href="http://llvm.org/viewvc/llvm-project?view=revision&revision=181632">http://llvm.org/viewvc/llvm-project?view=revision&revision=181632</a>
PR14492: Debug Info: Support for values of non-integer non-type template
parameters.
This is only tested for global variables at the moment (& includes tests
for the unnamed parameter case, since apparently this entire function
was completely untested previously)
-----------------------------------------------
-----------------------------------------------
<a href="http://llvm.org/viewvc/llvm-project?view=revision&revision=181634">http://llvm.org/viewvc/llvm-project?view=revision&revision=181634</a>
PR14992: Debug Info: Support more non-type template parameters
* Provide DW_TAG_template_value_parameter for pointers, function
pointers, member pointers, and member function pointers (still missing
support for template template parameters which GCC encodes as a
DW_TAG_GNU_template_template_param)
* Provide values for all but the (member & non-member) function pointer case.
Simple constant integer values for member pointers (offset within the
object) and address for the value pointer case. GCC doesn't provide a
value for the member function pointer case so I'm not sure how, if at
all, GDB supports encoding that. & non-member function pointers should
follow shortly in a subsequent patch.
* Null pointer value encodings of all of these types, including
correctly encoding null data member pointers as -1.
-----------------------------------------------
-----------------------------------------------
<a href="http://llvm.org/viewvc/llvm-project?view=revision&revision=181685">http://llvm.org/viewvc/llvm-project?view=revision&revision=181685</a>
Debug Info: PR14992: Support values for non-type template parameters of
function type
-----------------------------------------------</pre>
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