clang: linker command failed with exit code 1 - c

I checked multiple questions like this, but none of the answers worked in my case.
I have a simple "hello world!" c program. When I tried to run it using clang, I get the following error:
/..//bin/ld: cannot find -lgcc
/..//bin/ld: cannot find -lgcc_s
clang: error: linker command failed with exit code 1 (use -v to see invocation)
when I do -v it gives me:
clang version 3.4 (branches/release_34)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Selected GCC installation:
"/nfs/projects/zephyr/Ruturaj/softboundcets-34/softboundcets-llvm-clang34/Debug+Asserts/bin/clang" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -disable-free -main-file-name agsd.c -mrelocation-model static -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-linker-version 2.29.1 -v -resource-dir /nfs/projects/zephyr/Ruturaj/softboundcets-34/softboundcets-llvm-clang34/Debug+Asserts/bin/../lib/clang/3.4 -internal-isystem /usr/local/include -internal-isystem /nfs/projects/zephyr/Ruturaj/softboundcets-34/softboundcets-llvm-clang34/Debug+Asserts/bin/../lib/clang/3.4/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir /projects/zephyr/Ruturaj -ferror-limit 19 -fmessage-length 96 -mstackrealign -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -vectorize-slp -o /tmp/agsd-ad6d7d.o -x c agsd.c
clang -cc1 version 3.4 based upon LLVM 3.4 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/nfs/projects/zephyr/Ruturaj/softboundcets-34/softboundcets-llvm-clang34/Debug+Asserts/bin/../lib/clang/3.4/include
/usr/include
End of search list.
"/..//bin/ld" --hash-style=gnu --no-add-needed --build-id --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o a.out /lib/../lib64/crt1.o /lib/../lib64/crti.o /lib/../lib64/crtbegin.o -L/lib/../lib64 -L/usr/lib/../lib64 -L/lib -L/usr/lib /tmp/agsd-ad6d7d.o -L/usr/lib/ -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed crtend.o /lib/../lib64/crtn.o
/..//bin/ld: cannot find -lgcc
/..//bin/ld: cannot find -lgcc_s
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I tried to run it with:
clang -L /usr/lib/gcc/x86_64-redhat-linux/8
But, it is still not working.
I installed newer llvm (6.0) and it worked fine. But, I need this 3.4 version to run a project.

Related

Cannot cross-compiling code using clang++

Command:
I am trying to cross compile a simple C++ program using clang++. I'm using Linaro gcc tool-chain to obtain the library and other includes required.
${root}/bin/clang++ --target=arm-linux-gnueabihf --rtlib=compiler-rt --stdlib=libc++ -nostdinc++ -I${root}/include/c++/v1 -Wl,-L${root}/lib --sysroot ${sysroot} --gcc-toolchain=/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf -rpath ${root}/lib TestCodeX86toARM.cpp -o Test -v
The value of root and sysroot is as follows:
root=/path/to/clang/install_dir
sysroot=/path/to/linarogcc/arm-linux-gnueabihf/libc
TestCodeX86toARM.cpp is just a hello world code
output:
clang version 10.0.0
Target: arm-unknown-linux-gnueabihf
Thread model: posix
InstalledDir: /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/bin
Found candidate GCC installation: /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0
Selected GCC installation: /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0
Candidate multilib: .;#m32
Selected multilib: .;#m32
"/home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/bin/clang-10" -cc1 -triple armv6kz-unknown-linux-gnueabihf -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name TestCodeX86toARM.cpp -mrelocation-model static -mthread-model posix -mframe-pointer=all -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -target-cpu arm1176jzf-s -target-feature +strict-align -target-abi aapcs-linux -mfloat-abi hard -fallow-half-arguments-and-returns -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -v -nostdinc++ -resource-dir /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/clang/10.0.0 -I /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/include/c++/v1 -isysroot /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc -internal-isystem /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/local/include -internal-isystem /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/clang/10.0.0/include -internal-externc-isystem /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/include -internal-externc-isystem /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/include -fdeprecated-macro -fdebug-compilation-dir /home/user/Tejas/CrossCopileTestCode -ferror-limit 19 -fmessage-length 0 -fno-signed-char -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -faddrsig -o /tmp/TestCodeX86toARM-438a38.o -x c++ TestCodeX86toARM.cpp
clang -cc1 version 10.0.0 based upon LLVM 10.0.0 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/local/include"
ignoring nonexistent directory "/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/include"
#include "..." search starts here:
#include <...> search starts here:
/home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/include/c++/v1
/home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/clang/10.0.0/include
/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/include
End of search list.
"/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0/../../../../arm-linux-gnueabihf/bin/ld" --sysroot=/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc -EL -z relro -X --hash-style=gnu --eh-frame-hdr -m armelf_linux_eabi -dynamic-linker /lib/ld-linux-armhf.so.3 -o Test /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/lib/../lib/crt1.o /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/lib/../lib/crti.o /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0/crtbegin.o -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0 -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0/../../../../arm-linux-gnueabihf/lib/../lib -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/lib/../lib -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/lib/../lib -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0/../../../../arm-linux-gnueabihf/lib -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/lib -L/home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/lib -L/home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib -rpath /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib /tmp/TestCodeX86toARM-438a38.o -lc++ -lm /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/clang/10.0.0/lib/linux/libclang_rt.builtins-armhf.a -lc /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/clang/10.0.0/lib/linux/libclang_rt.builtins-armhf.a /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/lib/gcc/arm-linux-gnueabihf/7.5.0/crtend.o /home/user/Tejas/LLVM/gcc-linaro-7.5.0-2019.12-x86_64_arm-linux-gnueabihf/arm-linux-gnueabihf/libc/usr/lib/../lib/crtn.o
/home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/libc++.so.1: file not recognized: File format not recognized
clang-10: error: linker command failed with exit code 1 (use -v to see invocation)
Your linker is trying to link against libc++. However clang cant find this library in your arm tool-chain ( probably your arm tool-chain is providing libstdc++). So the only libc++ found by the linker is /home/user/Tejas/clang+llvm-10.0.0-x86_64-linux-gnu-ubuntu-18.04/lib/libc++.so.1 which is probably an x86 library ( you can confirm that with objdump or readelf).
Try to replace --stdlib=libc++ by --stdlib=libstdc++ in your command line.

openmp not linking correctly when compiling with clang

I have built clang 4.0 from source on Ubuntu 16.04 and am trying to compile a simple OpenMP program but receive the following errors.
/tmp/test-7f2c7c.o: In function `main':
/home/me/sf_shared/test.c:(.text+0x52): undefined reference to `__kmpc_fork_call'
/tmp/test-7f2c7c.o: In function `.omp_outlined.':
/home/me/sf_shared/test.c:(.text+0xd9): undefined reference to `__kmpc_for_static_init_4'
/home/me/sf_shared/test.c:(.text+0x16d): undefined reference to `__kmpc_for_static_fini'
clang-4.0: error: linker command failed with exit code 1 (use -v to see invocation)
To compile I am using ./bin/clang ~/sf_shared/tset.c -fopenmp where bin is the bin folder where I have build clang from source and test.c is a simple openmp program.
Adding -v results in the following
clang version 4.0.1
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/me/release_build/./bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.0.0
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0
Candidate multilib: .;#m64
Selected multilib: .;#m64
"/home/me/release_build/bin/clang-4.0" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all
-disable-free -disable-llvm-verifier -discard-value-names -main-file-name test.c -mrelocation-model static
-mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables
-fuse-init-array -target-cpu x86-64 -v -dwarf-column-info -debugger-tuning=gdb -resource-dir /home/me
/release_build/bin/../lib/clang/4.0.1 -internal-isystem /usr/local/include -internal-isystem /home/me
/release_build/bin/../lib/clang/4.0.1/include -internal-externc-isystem /usr/include/x86_64-linux-gnu
-internal-externc-isystem /include -internal-externc-isystem /usr/include -fdebug-compilation-dir /home/me
/release_build -ferror-limit 19 -fmessage-length 117 -fopenmp -fobjc-runtime=gcc -fdiagnostics-show-option -o
tmp/test-c9b0bd.o -x c /home/me/sf_shared/test.c
clang -cc1 version 4.0.1 based upon LLVM 4.0.1 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/home/me/release_build/bin/../lib/clang/4.0.1/include
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
"/usr/bin/ld" -z relro --hash-style=gnu --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/
ld-linux-x86-64.so.2 -o a.out /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc
/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/crtbegin.o -L/usr/
lib/gcc/x86_64-linux-gnu/5.4.0 -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu -L/lib/
x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../.. -L/
home/me/release_build/bin/../lib -L/lib -L/usr/lib /tmp/test-c9b0bd.o -lomp -lgcc --as-needed -lgcc_s
--no-as-needed -lpthread -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-linux-gnu/5.4.0/
crtend.o /usr/lib/gcc/x86_64-linux-gnu/5.4.0/../../../x86_64-linux-gnu/crtn.o
/tmp/test-c9b0bd.o: In function `main':
/home/me/sf_shared/test.c:(.text+0x52): undefined reference to `__kmpc_fork_call'
/tmp/test-c9b0bd.o: In function `.omp_outlined.':
/home/me/sf_shared/test.c:(.text+0xd9): undefined reference to `__kmpc_for_static_init_4'
/home/me/sf_shared/test.c:(.text+0x15f): undefined reference to `__kmpc_for_static_fini'
clang-4.0: error: linker command failed with exit code 1 (use -v to see invocation)
Any idea as to why the openmp sections are not being linked correctly?
I've include test.c below if anyone is curious
#include <omp.h>
#include <stdio.h>
int main() {
printf("Max threads: %d\n", omp_get_max_threads());
omp_set_dynamic(0);
omp_set_num_threads(omp_get_max_threads());
#pragma omp parallel for
for (int i = 0; i < 32; ++i) {
printf("I am thread %d\n", omp_get_thread_num());
}
}
Installing the libiomp5 package and changing -fopenmp to -fopenmp=libiomp5 when compiling has resolved the issue.

Not able to find when gcc links to libc

I was trying to study the compilation/link process in detail using gcc.
So made a test .c file and compiled it using the verbose option of gcc.
gcc -v main.c
But in the verbose messages I cant find anywhere where it refers to libc. The only relevant (might be) thing I find is crtn.o and crtend.o
But when I do
readelf -d a.out
I can find the dependency on libc.so.6. So I am confused whether gcc doesn't output the message related to dynamically linking to libc or I am missing something.
The relevant message for the linker is as below:
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/4.8/collect2 --sysroot=/ --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -z relro /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/4.8 -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../.. /tmp/ccYoVOxt.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-linux-gnu/4.8/crtend.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crtn.o
The library operand you are looking for is -lc. It's in there, use Ctrl+F to find it.
See also the ld documentation.

Compilation error: /usr/bin/ld: cannot find -lclntsh

While trying to compile a C program using make file, I am facing the following linking error described below.
I know this kind of issues are already discussed in many other posts, but I tried with solutions suggested in them but they all did not work.
/usr/bin/ld: cannot find -lclntsh
libclntsh.so and libclntsh.so.10.1 are present in oracle path /u01/app/oracle/product/10.2.0/lib and that is being given as -L option in make file. Still I am facing the issue:-
Linking yieldrpt ...
cc -v -g -D_HPUX_SOURCE -DPARETO -Wl,-aarchive -L/u01/app/oracle/product/10.2.0/lib/ yieldrpt.o -lclntsh `cat /u01/app/oracle/product/10.2.0/lib/ldflags` -lmalloc -ldl -lm \
-lmalloc -o yieldrpt
Using built-in specs.
Target: i386-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --disable-plugin --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic --host=i386-redhat-linux
Thread model: posix
gcc version 4.1.2 20080704 (Red Hat 4.1.2-54)
/usr/libexec/gcc/i386-redhat-linux/4.1.2/collect2 --eh-frame-hdr -m elf_i386 --hash-style=gnu -dynamic-linker /lib/ld-linux.so.2 -o yieldrpt /usr/lib/gcc/i386-redhat-linux/4.1.2/../../../crt1.o /usr/lib/gcc/i386-redhat-linux/4.1.2/../../../crti.o /usr/lib/gcc/i386-redhat-linux/4.1.2/crtbegin.o -L/u01/app/oracle/product/10.2.0/lib/ -L/usr/lib/gcc/i386-redhat-linux/4.1.2 -L/usr/lib/gcc/i386-redhat-linux/4.1.2 -L/usr/lib/gcc/i386-redhat-linux/4.1.2/../../.. -aarchive yieldrpt.o -lclntsh -lnbeq10 -lnhost10 -lnus10 -lnldap10 -lldapclnt10 -lnsslb10 -lntcp10 -lntcps10 -lnsslb10 -lntcp10 -lntns10 -lmalloc -ldl -lm -lmalloc -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/i386-redhat-linux/4.1.2/crtend.o /usr/lib/gcc/i386-redhat-linux/4.1.2/../../../crtn.o
/usr/bin/ld: cannot find -lclntsh
collect2: ld returned 1 exit status
make: *** [yieldrpt] Error 1
Please let me know if any other info is needed.
Thank you
You are passing -aarchive to the linker. This is an HP/UX compatibility option
that is synonymous with -Bstatic, which directs the linker not to link dynamic
libraries. Hence your libclntsh.so is ignored. See the documentation
If you don't know why this option is there you may well remove it and try again. If you
know it is necessary then you will have to find static libraries, including libclntsh.a to
link against.
If you have libclntsh.so.12.1 or similar is already installed you may try symlinking the library to libclntsh.so with the following command: ln -s /usr/lib/oracle/12.1/client64/lib/libclntsh.so.12.1 /usr/lib/oracle/12.1/client64/lib/libclntsh.so
For me it was /usr/bin/ld: cannot find -lclntshcore. For some reason, the following symlink is missing.
libclntshcore.so -> /home/ubuntu/ora2pg/instantclient_12_2/libclntshcore.so.12.1
[oracle#em12c bin]$ pwd
/u01/em12c/middleware/oms/bin
[oracle#em12c bin]$ export ORACLE_HOME=/u01/em12c/middleware/oms
[oracle#em12c bin]$ ./genclntsh
[oracle#em12c bin]$ ls -l /u01/em12c/middleware/oms/lib32//libclntsh.so
lrwxrwxrwx. 1 oracle oinstall 17 Oct 23 22:16 /u01/em12c/middleware/oms/lib32//libclntsh.so -> libclntsh.so.11.1

Code coverage in clang

I'm trying to generate code coverage files for a small C program compiled with clang on Debian Linux. Here's what I've done:
neuron#debian:~/temp$ ls
main.c test.c test.h
neuron#debian:~/temp$ clang *.c
neuron#debian:~/temp$ ./a.out
0
This is exactly as expected, I can compile and run things. Now trying to enable coverage.
neuron#debian:~/temp$ clang --coverage *.c
/usr/bin/ld: cannot find /usr/bin/../lib/libprofile_rt.a: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Trying to include the library for linking.
neuron#debian:~/temp$ clang --coverage -lprofile_rt *.c
/usr/bin/ld: cannot find -lprofile_rt
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Finding the library:
neuron#debian:~/temp$ find / -name \*profile_rt\* 2>/dev/null
/usr/lib/llvm-3.0/lib/libprofile_rt.so
/usr/lib/llvm-3.0/lib/libprofile_rt.a
neuron#debian:~/temp$ clang --coverage -lprofile_rt -L/usr/lib/llvm-3.0/lib *.c
/usr/bin/ld: cannot find /usr/bin/../lib/libprofile_rt.a: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Here's more verbose output of the last command: http://pastie.org/8468331. What concerns me there:
the linker uses tons of gcc libraries to link with (though this may be a result of llvm not having it's own binunitls);
profiling library is being searched for at /usr/bin/../lib/libprofile_rt.a instead of the path I provided.
If we pass the arguments to the linker the output is the same:
neuron#debian:~/temp$ clang --coverage -Wl,-L/usr/lib/llvm-3.0/lib *.c -lprofile_rt
/usr/bin/ld: cannot find /usr/bin/../lib/libprofile_rt.a: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
What do I do wrong?
Try changing the order of your link line from
clang --coverage -lprofile_rt -L/usr/lib/llvm-3.0/lib *.c
to
clang --coverage -L/usr/lib/llvm-3.0/lib *.c -lprofile_rt
Ok, doesn't seem like the linker is getting your -L for some reason. Maybe try
clang --coverage -Wl,L/usr/lib/llvm-3.0/lib *.c -lprofile_rt
The only way I've been able to resolve this issue is by creating a symbolic link to where LLVM/clang is looking for the library. I'm thinking this is a way for package maintainers to manage which feature-library is used by the host system.
ln -s /usr/lib/llvm-3.0/lib/libprofile_rt.a /usr/lib/libprofile_rt.a
Coverage, and other optional -f<***> profile features work as expected. I can verify this by adding the verbose -v switch.
Debian clang version 3.0-6.2 (tags/RELEASE_30/final) (based on LLVM 3.0)
Target: arm-unknown-linux-gnueabihf
Thread model: posix
"/usr/bin/clang" -cc1 -triple armv4t-unknown-linux-gnueabihf -S -disable-free -disable-llvm-verifier -main-file-name example.c -mrelocation-model static -mdisable-fp-elim -mconstructor-aliases -target-abi apcs-gnu -target-cpu arm1136jf-s -mfloat-abi hard -target-linker-version 2.22 -momit-leaf-frame-pointer -v -femit-coverage-notes -femit-coverage-data -resource-dir /usr/bin/../lib/clang/3.0 -fmodule-cache-path /var/tmp/clang-module-cache -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/clang/3.0/include -internal-externc-isystem /usr/include/arm-linux-gnueabihf -internal-externc-isystem /usr/include -ferror-limit 19 -fmessage-length 130 -fno-signed-char -fgnu-runtime -fobjc-runtime-has-arc -fobjc-runtime-has-weak -fobjc-fragile-abi -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/example-lLKOP1.s -x c example.c
clang -cc1 version 3.0 based upon llvm 3.0 hosted on arm-unknown-linux-gnueabihf
ignoring nonexistent directory "/usr/bin/../lib/clang/3.0/include"
ignoring nonexistent directory "/usr/bin/../lib/clang/3.0/include"
ignoring duplicate directory "/usr/local/include"
ignoring duplicate directory "/usr/include/arm-linux-gnueabihf"
ignoring duplicate directory "/usr/include/arm-linux-gnueabihf"
ignoring duplicate directory "/usr/include/arm-linux-gnueabihf"
ignoring duplicate directory "/usr/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include
/usr/include/arm-linux-gnueabihf
/usr/include
/usr/include/clang/3.0/include/
/usr/lib/gcc/arm-linux-gnueabihf/4.6/include/
/usr/lib/gcc/arm-linux-gnueabihf/4.6/include-fixed/
End of search list.
"/usr/bin/as" -o /tmp/example-WbJHFT.o /tmp/example-lLKOP1.s
"/usr/bin/ld" -X --hash-style=both --build-id --eh-frame-hdr -m armelf_linux_eabi -dynamic-linker /lib/ld-linux-armhf.so.3 -o example.o /usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../arm-linux-gnueabihf/crt1.o /usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../arm-linux-gnueabihf/crti.o /usr/lib/gcc/arm-linux-gnueabihf/4.6/crtbegin.o -L/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../arm-linux-gnueabihf -L/lib/arm-linux-gnueabihf -L/usr/lib/arm-linux-gnueabihf -L/usr/lib/gcc/arm-linux-gnueabihf/4.6 -L/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../arm-linux-gnueabihf -L/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../.. -L/lib/arm-linux-gnueabihf -L/lib -L/usr/lib/arm-linux-gnueabihf -L/usr/lib /tmp/example-WbJHFT.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed \
/usr/lib/gcc/arm-linux-gnueabihf/4.6/crtend.o \
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../arm-linux-gnueabihf/crtn.o \
/usr/bin/../lib/libprofile_rt.a

Resources