undefined reference to '__mulodi4'

[Quuxplusone]

Bugzilla Link	PR14469
Status	REOPENED
Importance	P normal
Reported by	Oleksandr Motsak (malex984@gmail.com)
Reported on	2012-11-30 14:47:49 -0800
Last modified on	2019-03-23 15:26:56 -0700
Version	3.1
Hardware	PC Linux
CC	antoshkka@gmail.com, echristo@gmail.com, keremkat+llvm@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, lukebenes@hotmail.com, malex984@gmail.com, nikita.ppv@gmail.com, pawel@32bitmicro.com, sean@rogue-research.com, willdtz@gmail.com, zonr.xchg@gmail.com
Fixed by commit(s)
Attachments	32.cc (348 bytes, text/x-c++src)
Blocks	PR24345
Blocked by
See also	PR35922

Created attachment 9628
test

Multiplication of two "long long int" translates into the code that requires to
call missing function '__mulodi4' if compiled with -ftrapv -m32 (on 64 bit
linux)

Please compile the attached code with "clang -ftrapv -m32" (at least on a 64
bit machine).

Removing either "-ftrapv" or "-m32" will produce fine executable.

ps:
clang version 3.1 (branches/release_31)
Target: x86_64-unknown-linux-gnu

[Quuxplusone]

Attached 32.cc (348 bytes, text/x-c++src): test

[Quuxplusone]

You'll need to use compiler-rt instead of libgcc for your runtime library. It
contains mulodi4.

[Quuxplusone]

(In reply to comment #1)
> You'll need to use compiler-rt instead of libgcc for your runtime library. It
> contains mulodi4.

Thanks, what is the best way to do that?

[Quuxplusone]

Besides gcc -ftrapv -m32 leads to 'call __mulvdi3' on the same place

[Quuxplusone]

mulvidi3 is fine if you want to abort on overflow, but there are language rules with overflow that'll cause an exception to be thrown (c++ new for example) where you don't want an abort, hence the mulvdi3.

http://compiler-rt.llvm.org/

has the information (via a link to clang's page) that you'll want for using compiler-rt with your clang.

[Quuxplusone]

(In reply to comment #4)
> mulvidi3 is fine if you want to abort on overflow, but there are language
rules
> with overflow that'll cause an exception to be thrown (c++ new for example)
> where you don't want an abort, hence the mulvdi3.

Since compiling with "clang -ftrapv" on a x86_64 bit machine work just fine
without any additional libraries (simply sends signals) it really looks like an
issue of clang's ftapv implementation on x86_32.
Therefore i believe that such things can only be intended if all the required
libraries (for any possible compiler output) are packaged together with with
clang so that they can be imbedded by clang without any extra tweaks...

Is there any way to make clang to generate the same code as gcc in such cases
(and thus avoid compiler-rt)?

> http://compiler-rt.llvm.org/
> has the information (via a link to clang's page) that you'll want for using
> compiler-rt with your clang.

i will have to build it with -m32, right?

[Quuxplusone]

Ok, i switched to the latest clang:

ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]= 0x732b5091cf73e6fb06bb2fdc32f9f620978ef291, stripped, clang version 3.2 (tags/RELEASE_32/final) Target: x86_64-unknown-linux-gnu Thread model: posix

and built the following libraries:

/usr/lib/clang/3.2/lib/linux/libclang_rt.asan-i386.a /usr/lib/clang/3.2/lib/linux/libclang_rt.asan-x86_64.a /usr/lib/clang/3.2/lib/linux/libclang_rt.full-i386.a /usr/lib/clang/3.2/lib/linux/libclang_rt.full-x86_64.a /usr/lib/clang/3.2/lib/linux/libclang_rt.profile-i386.a /usr/lib/clang/3.2/lib/linux/libclang_rt.profile-x86_64.a /usr/lib/clang/3.2/lib/linux/libclang_rt.tsan-x86_64.a /usr/lib/clang/3.2/lib/linux/libclang_rt.ubsan-i386.a /usr/lib/clang/3.2/lib/linux/libclang_rt.ubsan-x86_64.a

Nevertheless compiling the previously attached tests with clang -v -ftrapv -m32 ./32.cc still leads to the following error:

clang version 3.2 (tags/RELEASE_32/final) Target: i386-unknown-linux-gnu Thread model: posix "/usr/bin/clang" -cc1 -triple i386-unknown-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name 32.cc -mrelocation-model static -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -fuse-init-array -target-cpu pentium4 -target-linker-version 2.23.1 -momit-leaf-frame-pointer -v -resource-dir /usr/bin/../lib/clang/3.2 -fmodule-cache-path /var/tmp/clang-module-cache -internal-isystem /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2 -internal-isystem /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2/x86_64-unknown-linux-gnu/32 -internal-isystem /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2/backward -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/clang/3.2/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /home/motsak/Downloads -ferror-limit 19 -fmessage-length 190 -ftrapv -mstackrealign -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/32-Eu9MBw.o -x c++ ./32.cc clang -cc1 version 3.2 based upon LLVM 3.2 default target x86_64-unknown-linux-gnu ignoring nonexistent directory "/include"

include "..." search starts here:

include <...> search starts here:

/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2 /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2/x86_64-unknown-linux-gnu/32 /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2/backward /usr/local/include /usr/bin/../lib/clang/3.2/include /usr/include End of search list. "/usr/bin/ld.gold" --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 -o a.out /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../lib32/crt1.o /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../lib32/crti.o /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/32/crtbegin.o -L/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/32 -L/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../lib32 -L/lib/../lib32 -L/usr/lib/../lib32 -L/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2 -L/usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../.. -L/lib -L/usr/lib /tmp/32-Eu9MBw.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/32/crtend.o /usr/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../lib32/crtn.o /tmp/32-Eu9MBw.o:./32.cc:function main: error: undefined reference to '__mulodi4' clang: error: linker command failed with exit code 1 (use -v to see invocation)

I would guess that clang generates code assuming libclang_rt, but linker ignores all libclang_rt.*.a and sticks to libgcc instead.

What did i do wrong?

ps: 'clang -fsanitize=undefined -m32 ./32.cc' leads to the same error message.

[Quuxplusone]

Same error occurs while compiling code on Windows with clang++ and flag -ftrapv:

"clang++" -c -x c++ -O0 -g -ftrapv -fno-inline -Wall -g -ftrapv -
DBOOST_ALL_NO_LIB=1 -DBOOST_TEST_NO_AUTO_LINK=1 -I".." -o
"F:\boost\Clang\trunk\results\boost\bin.v2\libs\conversion\test\lexical_cast_integral_types_test.test\clang-
linux-3.2\debug\link-static\lexical_cast_integral_types_test.obj"
"..\libs\conversion\test\lexical_cast_integral_types_test.cpp"

Link [2013-03-31 00:08:59 UTC]: fail

  "clang++"    -o "F:\boost\Clang\trunk\results\boost\bin.v2\libs\conversion\test\lexical_cast_integral_types_test.test\clang-linux-3.2\debug\link-static\lexical_cast_integral_types_test.exe" "F:\boost\Clang\trunk\results\boost\bin.v2\libs\conversion\test\lexical_cast_integral_types_test.test\clang-linux-3.2\debug\link-static\lexical_cast_integral_types_test.obj" "F:\boost\Clang\trunk\results\boost\bin.v2\libs\test\build\clang-linux-3.2\debug\link-static\libboost_unit_test_framework-clang32-d-1_54.lib"    -g

F:\boost\Clang\trunk\results\boost\bin.v2\libs\conversion\test\lexical_cast_integral_types_test.test\clang-
linux-3.2\debug\link-static\lexical_cast_integral_types_test.obj: In function
`Z39test_conversion_from_integral_to_stringIxcEvT0_':

Operating System: Windows 7 Ultimate 64-bit, Service Pack 1
    Microsoft Windows [Version 6.1.7601]

Compiler: MinGW-w64's clang-3.2.
    clang version 3.2 (tags/RELEASE_32/final)
    Target: i686-w64-mingw32
    Thread model: posix

[Quuxplusone]

_This bug has been marked as a duplicate of bug 13897_

[Quuxplusone]

This was incorrectly closed as a duplicate. bug 13897 is fixed, but the test
case here is still not working.

$ gcc -ftrapv -m32 32.cc

$ clang -ftrapv -m32 32.cc
/usr/bin/ld: /tmp/32-cc3c8b.o: in function `main':
32.cc:(.text+0x4f): undefined reference to `__mulodi4'
clang-9: error: linker command failed with exit code 1 (use -v to see
invocation)

$ clang --version
clang version 9.0.0 (https://github.com/llvm/llvm-project.git
0f472e1d01d60b6e615cd71a09b0a52eb8e42072)
Target: i686-pc-linux-gnu