clang appears not to be linking to a library - c++

Question

I boiled down the problem to the following example:
int main()
{
try {
throw false;
} catch (bool x)
{
if (x)
{
return 0;
}
else
{
return 1;
}
}
}
generates the following errors on Coliru:
/tmp/main-c8b47a.o: In function `main':
main.cpp:(.text+0xf): undefined reference to `typeinfo for bool'
/tmp/main-c8b47a.o: In function `GCC_except_table0':
main.cpp:(.gcc_except_table+0x30): undefined reference to `typeinfo for bool'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Cmd line:
clang++ -std=c++11 -stdlib=libc++ -O2 -Wall -pedantic -pthread main.cpp && ./a.out
This sounds like it's not linking to a library. Does anyone know which and what the command line switches would be? I've not used clang before. This works under g++.
This is the output with the -v switch:
clang version 3.6.0 (tags/RELEASE_360/final 235480)
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/4.6.4
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.7.3
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.2
Found candidate GCC installation: /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.8.2
Found candidate GCC installation: /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.9.0
Found candidate GCC installation: /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.9.2
Found candidate GCC installation: /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.1.0
Found candidate GCC installation: /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0
Selected GCC installation: /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0
Candidate multilib: .;#m64
Selected multilib: .;#m64
"/usr/local/bin/clang" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -disable-free -disable-llvm-verifier -main-file-name main.cpp -mrelocation-model static -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -target-linker-version 2.22 -momit-leaf-frame-pointer -v -dwarf-column-info -resource-dir /usr/local/bin/../lib/clang/3.6.0 -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/include -internal-isystem /usr/local/bin/../lib/clang/3.6.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wall -pedantic -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /tmp/1441759762.34715 -ferror-limit 19 -fmessage-length 0 -pthread -mstackrealign -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -vectorize-loops -vectorize-slp -o /tmp/main-47c098.o -x c++ main.cpp
clang -cc1 version 3.6.0 based upon LLVM 3.6.0 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/include/c++/v1
/usr/local/include
/usr/local/bin/../lib/clang/3.6.0/include
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
"/usr/bin/ld" --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0/crtbegin.o -L/usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0 -L/usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0/../../../../lib64 -L/usr/local/bin/../lib64 -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0/../../.. -L/usr/local/bin/../lib -L/lib -L/usr/lib /tmp/main-47c098.o -lc++ -lm -lgcc_s -lgcc -lpthread -lc -lgcc_s -lgcc /usr/local/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0/crtend.o /usr/lib/x86_64-linux-gnu/crtn.o
/tmp/main-47c098.o: In function `main':
main.cpp:(.text+0xf): undefined reference to `typeinfo for bool'
/tmp/main-47c098.o: In function `GCC_except_table0':
main.cpp:(.gcc_except_table+0x30): undefined reference to `typeinfo for bool'
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

It looks like you need to add -lsupc++ after main.cpp (see it live):
clang++ -std=c++11 -stdlib=libc++ -O2 -Wall -pedantic -pthread main.cpp -lsupc++
^^^^^^^^
As Andre Kostur notes the libc++ documentation recommends the following, although I can not seem to get this to work on Coliru:
Unfortunately you can't simply run clang with "-stdlib=libc++" at this
point, as clang is set up to link for libc++ linked to libsupc++. To
get around this you'll have to set up your linker yourself (or patch
clang). For example,
clang++ -stdlib=libc++ helloworld.cpp -nodefaultlibs -lc++ -lcxxrt -lm -lc -lgcc_s -lgcc
Alternately, you could just add libcxxrt to your libraries list, which
in most situations will give the same result:
clang++ -stdlib=libc++ helloworld.cpp -lcxxrt
This looks related to issues being discussed in this thread Making libc++ on Linux user-friendly, with selective quotes below:
Here's the problem: when building libc++, the linker finds the various
ABI functions in libstdc++, and is quite happy with them being there.
When Clang calls the linker for the actual program, though, it doesn't
pass along a link flag for libstdc++, only for libc++. Thus, the links
fails.
and:
This again can be worked around by explicitly specifying linking against the source library, and here -lsupc++ works.
Also see Linux equivalent of Windows DLL forwarders or MacOS reexport_library.