<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 --- - Non-standard install of libstdc++, clang does not find a valid gcc install / does not find c++ headers"
href="http://llvm.org/bugs/show_bug.cgi?id=21152">21152</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Non-standard install of libstdc++, clang does not find a valid gcc install / does not find c++ headers
</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>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>Driver
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>phantall+llvm@gmail.com
</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>configured with:
PATH=/usr/somenetworkmount/tools/gcc/latest/linux/bin:${PATH}
../../src/llvm/llvm-3.5/configure
--prefix=/usr/somenetworkmount/tools/llvm/3.5/linux/release --enable-optimized
CC=gcc CXX=g++ --with-gcc-toolchain
Everything built, but `make check` failed because it was finding the system
libstdc++.so.6 (I can't control that installation, hence the non-standard
configuration). I then ran `make check` setting LD_LIBRARY_PATH to compensate
and the checks all passed.
However, it fails to find c++ headers (I hope you'll forgive my not typing
everything out, but I'm testing this on an airgapped machine -- I don't have
the means to test this on a machine with internet access and re-typing the
output of the below commands would be tedious and probably unnecessary):
~ echo '#include <string>' | Release+Asserts/bin/clang -xc++ -v -
clang version 3.5.0
Target: x86_64-unknown-linux-gnu
Thread model: posix
(omitted call to clang with flags)
clang -cc1 version 3.5.0 based upon LLVM 3.5.0 default target
x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/mnt/scratch/tools/build/llvm-3.5/Release+Asserts/bin/../lib/clang/3.5.0/include
/usr/include
End of search list.
<stdin>:1:10: fatal error: "string" file not found
#include <string>
^
1 error generated.
I did a little digging; at or around lib/Driver/ToolChains.cpp:3474,
LibDir.str() returns the empty string. I backtracked from there to line 1237
and getGCCToolchainDir returns the simple string "yes".
So I re-ran the above command with a twist:
echo '#include <string>' | strace -f Release+Asserts/bin/clang -xc++ -v - |&
grep -P '\byes\b'
access("yes", F_OK) = -1 ENOENT (No such file or
directory)
... to which I conclude it thinks it has received the `--gcc-toolchain` option
(because it was configured/built using --with-gcc-toolchain?), but it doesn't
have a real path for the gcc toolchain.
To confirm this, I ran the following test and it succeeded:
echo '#include <string>' | Release+Asserts/bin/clang -xc++ -
--gcc-toolchain=/usr/somenetworkmount/tools/gcc/latest/Linux -c -o /tmp/blah.o
test -e /tmp/blah.o && echo 'It worked'
It worked</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>