[LLVMdev] [3.5 Release] Release Candidate 1 Sources and Binaries Available
Larry Evans
cppljevans at suddenlink.net
Thu Jul 31 10:20:50 PDT 2014
On 07/30/2014 09:53 PM, Ben Pope wrote:> On Wednesday, July 30, 2014
11:26 PM, Larry Evans wrote:
>> On 07/30/2014 10:06 AM, Larry Evans wrote:
>>> On 07/30/2014 12:35 AM, Ben Pope wrote:
>>>> On Wednesday, July 30, 2014 01:31 PM, Ben Pope wrote:
>>>>
>>>>> ldd your_built_clang | grep libstdc++
>>>>> chrpath -l your_built_clang
>>>>
>>>> Hmm, where "your_built_clang" should be the actual failing executable:
>>>> /home/evansl/dwnlds/llvm/3.5rc1/build/Release+Asserts/bin/llvm-tblgen
>>>>
>>>> Ben
>>> Here's the result:
>>>
>>> -*- mode: compilation; default-directory:
>>> "~/dwnlds/llvm/3.5rc1/build-variants/" -*-
>>> Compilation started at Wed Jul 30 10:03:38
>>>
>>> make -f my.mk chrpath
>>> cat hello_world.cpp
>>> #include <iostream>
>>> int main()
>>> {
>>> std::cout<<"Hello World!\n";
>>> return 0;
>>> }
>>> g++ --version
>>> g++ (GCC) 4.9.0
>>> Copyright (C) 2014 Free Software Foundation, Inc.
>>> This is free software; see the source for copying conditions. There
>>> is NO
>>> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
>>> PURPOSE.
>>>
>>> g++ hello_world.cpp
>>> ./a.out
>>> Hello World!
>>> ldd a.out | grep libstdc++
>>> libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6
>>> (0x00002b30fdb04000)
>>> chrpath -l a.out
>>> a.out: no rpath or runpath tag found.
>>> make: [chrpath] Error 2 (ignored)
>>> ldd ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen | grep
>>> libstdc++
>>> ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen:
>>> /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.20' not
>>> found (required by
>>> ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen)
>>> libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6
>>> (0x00002aee42a0f000)
>>> chrpath -l ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen
>>> ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen:
>>> RPATH=$ORIGIN/../lib
>>>
>>> Compilation finished at Wed Jul 30 10:03:38
>>>
>> OTHO, when LD_LIBRARY_PATH is set to /usr/local/...,
>> there's no "not found" error message:
>
> Is the test above without LD_LIBRARY_PATH set?
>
>> -*- mode: compilation; default-directory:
>> "~/dwnlds/llvm/3.5rc1/build-variants/" -*-
>> Compilation started at Wed Jul 30 10:22:38
>>
>> make -f my.mk libpath.chrpath
>> LD_LIBRARY_PATH=/usr/local/lib64 make -f my.mk chrpath
>> make[1]: Entering directory
>> `/home/evansl/dwnlds/llvm/3.5rc1/build-variants'
>> cat hello_world.cpp
>> #include <iostream>
>> int main()
>> {
>> std::cout<<"Hello World!\n";
>> return 0;
>> }
>> g++ --version
>> g++ (GCC) 4.9.0
>> Copyright (C) 2014 Free Software Foundation, Inc.
>> This is free software; see the source for copying conditions. There
>> is NO
>> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
>> PURPOSE.
>>
>> g++ hello_world.cpp
>> ./a.out
>> Hello World!
>> ldd a.out | grep libstdc++
>> libstdc++.so.6 => /usr/local/lib64/libstdc++.so.6
>> (0x00002ac7aded9000)
>> chrpath -l a.out
>> a.out: no rpath or runpath tag found.
>> make[1]: [chrpath] Error 2 (ignored)
>> ldd ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen | grep
>> libstdc++
>> libstdc++.so.6 => /usr/local/lib64/libstdc++.so.6
>> (0x00002b0112130000)
>> chrpath -l ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen
>> ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen:
>> RPATH=$ORIGIN/../lib
>> make[1]: Leaving directory
>> `/home/evansl/dwnlds/llvm/3.5rc1/build-variants'
>>
>> Compilation finished at Wed Jul 30 10:22:38
>
> I'm not 100% sure on this, but you seem to be configured to build
> executables with g++, but not run them, a cross-compiler of sorts. I'm
> not sure under what conditions executables built with g++-4.9 require
> GLIBCXX_3.4.20, perhaps try compiling something new like hello_regex.cpp.
When I installed g++-4.9, I used:
bash ../../../src/configure --disable-multilib
from directory:
/home/evansl/dwnlds/gcc/4.9.0/build/default/object
where /home/evansl/dwnlds/gcc/4.9.0 contained the bunzip
and untar of:
http://gcc.petsads.us/releases/gcc-4.9.0/gcc-4.9.0.tar.bz2
The manpage for --enable-multilib:
https://gcc.gnu.org/onlinedocs/libstdc++/manual/configure.html
says:
This is part of the generic multilib support for building cross
compilers.
So, using --disable-multilib, I think, would disable cross-compiling;
hence, your guess that the configuration was to build a
"cross-compiler of sorts" seems unlikely.
>
> I think you have a few of options:
>
> * Install g++-4.9 to /usr
> * Add /usr/local/lib64 to /etc/ld.so.conf
>
> The above two options means you're installing updated libstdc++
> system-wide.
>
> * Set the rpath of the binaries at build time: g++-4.9
> -Wl,-rpath=/usr/local/lib64
While installing g++-4.9, the messages output to the terminal
included something like that:
{{{---cut here---
.
.
.
----------------------------------------------------------------------
Libraries have been installed in:
/usr/local/lib/../lib64
If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:
- add LIBDIR to the `LD_LIBRARY_PATH' environment variable
during execution
- add LIBDIR to the `LD_RUN_PATH' environment variable
during linking
- use the `-Wl,-rpath -Wl,LIBDIR' linker flag
- have your system administrator add LIBDIR to `/etc/ld.so.conf'
See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------------------------------------------
make[4]: Nothing to be done for `install-data-am'.
make[4]: Leaving directory
`/home/evansl/dwnlds/gcc/4.9.0/build/default/object/x86_64-unknown-linux-gnu/libatomic'
make[3]: Leaving directory
`/home/evansl/dwnlds/gcc/4.9.0/build/default/object/x86_64-unknown-linux-gnu/libatomic'
make[2]: Leaving directory
`/home/evansl/dwnlds/gcc/4.9.0/build/default/object/x86_64-unknown-linux-gnu/libatomic'
make[1]: Leaving directory
`/home/evansl/dwnlds/gcc/4.9.0/build/default/object'
evansl at lje-OptiPlex-9020:~/dwnlds/gcc/4.9.0/build/default/object$
}}}---cut here---
>
> You may want to set that into the compiler options and recompile g++.
>
> * Copy /usr/local/lib64/libstdc++.so.6 to
> ./with_LD_LIBRARY_PATH/Release+Asserts/lib
>
> I'm out of ideas.
Thanks for the help, Ben.
>
> Ben
Unfortunately, this problem was caused by my using the default
configure for g++-4.9, which installed the library in user/local/lib64
instead of the "standard" places:
/lib/x86_64-linux-gnu
/usr/lib/x86_64-linux-gnu
(the above copied from /etc/ld.so.conf.d/ x86_64-linux-gnu.conf).
Unfortunately, there's no mention of this gotcha here:
http://clang.llvm.org/get_started.html
but there is if you follow the link, "Getting Started with the LLVM
System - Requirements", on that page to here:
http://llvm.org/docs/GettingStarted.html#requirements
which mentions the "pass lib flags to linker" solution:
You may need to pass a special linker flag,
-Wl,-rpath,$HOME/toolchains/lib or some variant thereof to get
things to find the libstdc++ DSO in this toolchain.
Now, when our hello_world problem is compiled with this addition, the
ldd and chrpath commands show it has the proper library. Since tblgen
was not recompiled with the options *and* LD_LIBRARY_PATH was not set
to the proper library, the ldd and chrpath commands show it still has
the library specified int the /etc/ld.so.conf.d files:
Compilation started at Thu Jul 31 12:04:48
make -f my.mk echo chrpath
echo "LLVM.src=/home/evansl/dwnlds/llvm/3.5rc1"
LLVM.src=/home/evansl/dwnlds/llvm/3.5rc1
echo "CXX.cmd=/usr/local/bin/g++ -L/usr/local/lib64 -Wl,-rpath
-Wl,/usr/local/lib64."
CXX.cmd=/usr/local/bin/g++ -L/usr/local/lib64 -Wl,-rpath
-Wl,/usr/local/lib64.
cat hello_world.cpp
#include <iostream>
int main()
{
std::cout<<"Hello World!\n";
return 0;
}
/usr/local/bin/g++ -L/usr/local/lib64 -Wl,-rpath -Wl,/usr/local/lib64
--version
g++ (GCC) 4.9.0
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
/usr/local/bin/g++ -L/usr/local/lib64 -Wl,-rpath -Wl,/usr/local/lib64
hello_world.cpp
./a.out
Hello World!
ldd a.out | grep libstdc++
libstdc++.so.6 => /usr/local/lib64/libstdc++.so.6 (0x00002ba9722e8000)
chrpath -l a.out
a.out: RPATH=/usr/local/lib64
ldd ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen | grep libstdc++
./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen:
/usr/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.20' not
found (required by ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6
(0x00002b315a15e000)
chrpath -l ./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen
./with_LD_LIBRARY_PATH/Release+Asserts/bin/llvm-tblgen: RPATH=$ORIGIN/../lib
Compilation finished at Thu Jul 31 12:04:49
Is there someway for the clang configure or make to figure this out
and automatically add the flags:
-L$(CXX.lib) -Wl,-rpath -Wl,$(CXX.lib)
to the compile command? That might save someone like me from making
the same mistake.
-regards,
Larry
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