clang-3.3 @3.3-r173279 can't link a C++ program with -fsanitize=thread

[acmorrow (Andrew C. Morrow)]

I'm using clang-3.3 @3.3-r173279 on OS X 10.8.3:

> /opt/local/bin/clang++-mp-3.3 --version
clang version 3.3 (trunk 173279)
Target: x86_64-apple-darwin12.3.0
Thread model: posix

Given a simple program, I'd like to build it with ThreadSanitizer by passing -fsanitize=thread, but the link step fails:

>  cat ./hello_world.cpp
#include <cstdlib>
#include <iostream>

int main(int argc, char* argv[]) {
    std::cout << "Hello, World!\n";
    return EXIT_SUCCESS;
}
>  /opt/local/bin/clang++-mp-3.3 ./hello_world.cpp -fsanitize=thread -o ./hello_world
Undefined symbols for architecture x86_64:
  "___tsan_func_entry", referenced from:
      _main in hello_world-RhjEoO.o
      ___cxx_global_var_init in hello_world-RhjEoO.o
      __GLOBAL__I_a in hello_world-RhjEoO.o
  "___tsan_func_exit", referenced from:
      _main in hello_world-RhjEoO.o
      ___cxx_global_var_init in hello_world-RhjEoO.o
      __GLOBAL__I_a in hello_world-RhjEoO.o
  "___tsan_init", referenced from:
      anon in hello_world-RhjEoO.o
  "___tsan_write4", referenced from:
      _main in hello_world-RhjEoO.o
  "___tsan_write8", referenced from:
      _main in hello_world-RhjEoO.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Here is a -### dump of the link line:

>  /opt/local/bin/clang++-mp-3.3 ./hello_world.cpp -fsanitize=thread -o ./hello_world -###
clang version 3.3 (trunk 173279)
Target: x86_64-apple-darwin12.3.0
Thread model: posix
 "/opt/local/libexec/llvm-3.3/bin/clang" "-cc1" "-triple" "x86_64-apple-macosx10.8.0" "-emit-obj" "-mrelax-all" "-disable-free" "-main-file-name" "hello_world.cpp" "-mrelocation-model" "pic" "-pic-level" "2" "-mdisable-fp-elim" "-masm-verbose" "-munwind-tables" "-target-cpu" "core2" "-target-linker-version" "134.9" "-resource-dir" "/opt/local/libexec/llvm-3.3/bin/../lib/clang/3.3" "-fmodule-cache-path" "/var/folders/n4/y_lrzpxd3n99l4frqx4m8llw0000gt/T/clang-module-cache" "-fdeprecated-macro" "-fdebug-compilation-dir" "/Users/andrew/Documents/10gen/dev/src/experiments/hello_world" "-ferror-limit" "19" "-fmessage-length" "167" "-fsanitize=thread" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-10.8.0" "-fobjc-dispatch-method=mixed" "-fobjc-default-synthesize-properties" "-fencode-extended-block-signature" "-fcxx-exceptions" "-fexceptions" "-fdiagnostics-show-option" "-fcolor-diagnostics" "-backend-option" "-vectorize-loops" "-o" "/var/folders/n4/y_lrzpxd3n99l4frqx4m8llw0000gt/T/hello_world-FGj5NL.o" "-x" "c++" "./hello_world.cpp"
 "/opt/local/libexec/llvm-3.3/bin/ld" "-demangle" "-dynamic" "-arch" "x86_64" "-macosx_version_min" "10.8.0" "-o" "./hello_world" "/var/folders/n4/y_lrzpxd3n99l4frqx4m8llw0000gt/T/hello_world-FGj5NL.o" "-lstdc++" "-lSystem" "/opt/local/libexec/llvm-3.3/bin/../lib/clang/3.3/lib/darwin/libclang_rt.osx.a"

Ideally, clang-3.3 would support ThreadSanitizer out of the box.

[acmorrow (Andrew C. Morrow)]

Cc Me!

[acmorrow (Andrew C. Morrow)]

I realized that a -v dump might be useful too:

>  /opt/local/bin/clang++-mp-3.3 ./hello_world.cpp -fsanitize=thread -o ./hello_world -v
clang version 3.3 (trunk 173279)
Target: x86_64-apple-darwin12.3.0
Thread model: posix
 "/opt/local/libexec/llvm-3.3/bin/clang" -cc1 -triple x86_64-apple-macosx10.8.0 -emit-obj -mrelax-all -disable-free -main-file-name hello_world.cpp -mrelocation-model pic -pic-level 2 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 134.9 -v -resource-dir /opt/local/libexec/llvm-3.3/bin/../lib/clang/3.3 -fmodule-cache-path /var/folders/n4/y_lrzpxd3n99l4frqx4m8llw0000gt/T/clang-module-cache -fdeprecated-macro -fdebug-compilation-dir /Users/andrew/Documents/10gen/dev/src/experiments/hello_world -ferror-limit 19 -fmessage-length 167 -fsanitize=thread -stack-protector 1 -mstackrealign -fblocks -fobjc-runtime=macosx-10.8.0 -fobjc-dispatch-method=mixed -fobjc-default-synthesize-properties -fencode-extended-block-signature -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -backend-option -vectorize-loops -o /var/folders/n4/y_lrzpxd3n99l4frqx4m8llw0000gt/T/hello_world-zx4JfM.o -x c++ ./hello_world.cpp
clang -cc1 version 3.3 based upon LLVM 3.3svn default target x86_64-apple-darwin12.3.0
ignoring nonexistent directory "/usr/include/c++/4.2.1/i686-apple-darwin10/x86_64"
ignoring nonexistent directory "/usr/include/c++/4.0.0"
ignoring nonexistent directory "/usr/include/c++/4.0.0/i686-apple-darwin8/"
ignoring nonexistent directory "/usr/include/c++/4.0.0/backward"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.2.1
 /usr/include/c++/4.2.1/backward
 /usr/local/include
 /opt/local/libexec/llvm-3.3/bin/../lib/clang/3.3/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
 "/opt/local/libexec/llvm-3.3/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.8.0 -o ./hello_world /var/folders/n4/y_lrzpxd3n99l4frqx4m8llw0000gt/T/hello_world-zx4JfM.o -lstdc++ -lSystem /opt/local/libexec/llvm-3.3/bin/../lib/clang/3.3/lib/darwin/libclang_rt.osx.a
Undefined symbols for architecture x86_64:
  "___tsan_func_entry", referenced from:
      _main in hello_world-zx4JfM.o
      ___cxx_global_var_init in hello_world-zx4JfM.o
      __GLOBAL__I_a in hello_world-zx4JfM.o
  "___tsan_func_exit", referenced from:
      _main in hello_world-zx4JfM.o
      ___cxx_global_var_init in hello_world-zx4JfM.o
      __GLOBAL__I_a in hello_world-zx4JfM.o
  "___tsan_init", referenced from:
      anon in hello_world-zx4JfM.o
  "___tsan_read4", referenced from:
      _main in hello_world-zx4JfM.o
  "___tsan_write4", referenced from:
      _main in hello_world-zx4JfM.o
  "___tsan_write8", referenced from:
      _main in hello_world-zx4JfM.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

[larryv (Lawrence Velázquez)]

Thanks. Please Cc relevant port maintainers in the future.

[jeremyhu (Jeremy Huddleston Sequoia)]

tsan isn't supported on darwin

[cooljeanius (Eric Gallager)]

Replying to jeremyhu@…:

tsan isn't supported on darwin

so shouldn't the flag just be ignored then when the user tries to use it?

[larryv (Lawrence Velázquez)]

Replying to egall@…:

Replying to jeremyhu@…:

tsan isn't supported on darwin

so shouldn't the flag just be ignored then when the user tries to use it?

It should probably throw an error, really. But that’s for upstream to fix.