rnk
commented
6 years ago Clang should probably always link clang_rt.builtins-$arch.lib on Windows if it exists.
However, even better would be to find a 64-bit mul with overflow function in MSVCRT and call that instead.
vitalybuka
Extended Description
The following code fails to link with clang-cl when building with -fsanitize=undefined:
// file main.cpp
include
include
using namespace std;
int main() { int64_t test = 1; test = 1000; cout << "1 1000 = " << test << endl; return 0; }
When changing int64_t to uint64_t, the code builds and runs as expected.
My build commands with "VS2015 x86 Native tools command prompt" including output:
c:\build>clang-cl -fsanitize=undefined -v main.cpp clang version 6.0.0 (tags/RELEASE_600/final) Target: i686-pc-windows-msvc Thread model: posix InstalledDir: C:\Program Files (x86)\LLVM\bin "C:\Program Files (x86)\LLVM\bin\clang-cl.exe" -cc1 -triple i686-pc-windows-msvc19.0.24215 -emit-obj -mrelax-all -mincremental-linker-compatible -disable-free -disable-llvm-verifier -discard-value-names -main-file-name main.cpp -mrelocation-model static -mthread-model posix -mdisable-fp-elim -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -target-cpu pentium4 -D_MT -flto-visibility-public-std --dependent-lib=libcmt --dependent-lib=oldnames -stack-protector 2 -fms-volatile -fdiagnostics-format msvc -dwarf-column-info -debugger-tuning=gdb -v -resource-dir "C:\Program Files (x86)\LLVM\lib\clang\6.0.0" -internal-isystem "C:\Program Files (x86)\LLVM\lib\clang\6.0.0\include" -internal-isystem "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" -internal-isystem "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\ATLMFC\INCLUDE" -internal-isystem "C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" -internal-isystem "C:\Program Files (x86)\Windows Kits\NETFXSDK\4.6.1\include\um" -internal-isystem "C:\Program Files (x86)\Windows Kits\8.1\include\\shared" -internal-isystem "C:\Program Files (x86)\Windows Kits\8.1\include\\um" -internal-isystem "C:\Program Files (x86)\Windows Kits\8.1\include\\winrt" -fdeprecated-macro -fdebug-compilation-dir "c:\build" -ferror-limit 19 -fmessage-length 120 "--dependent-lib=C:\Program Files (x86)\LLVM\lib\clang\6.0.0\lib\windows\clang_rt.ubsan_standalone-i386.lib" "--dependent-lib=C:\Program Files (x86)\LLVM\lib\clang\6.0.0\lib\windows\clang_rt.ubsan_standalone_cxx-i386.lib" -fsanitize=alignment,array-bounds,bool,builtin,enum,float-cast-overflow,float-divide-by-zero,integer-divide-by-zero,nonnull-attribute,null,pointer-overflow,return,returns-nonnull-attribute,shift-base,shift-exponent,signed-integer-overflow,unreachable,vla-bound -fsanitize-recover=alignment,array-bounds,bool,builtin,enum,float-cast-overflow,float-divide-by-zero,integer-divide-by-zero,nonnull-attribute,null,pointer-overflow,returns-nonnull-attribute,shift-base,shift-exponent,signed-integer-overflow,vla-bound -fno-use-cxa-atexit -fms-extensions -fms-compatibility -fms-compatibility-version=19.0.24215 -std=c++14 -fdelayed-template-parsing -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -o "C:\Users\m2_maier\AppData\Local\Temp\main-366977.obj" -x c++ main.cpp clang -cc1 version 6.0.0 based upon LLVM 6.0.0 default target i686-pc-windows-msvc
include "..." search starts here:
include <...> search starts here:
C:\Program Files (x86)\LLVM\lib\clang\6.0.0\include C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\ATLMFC\INCLUDE C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt C:\Program Files (x86)\Windows Kits\NETFXSDK\4.6.1\include\um C:\Program Files (x86)\Windows Kits\8.1\include\shared C:\Program Files (x86)\Windows Kits\8.1\include\um C:\Program Files (x86)\Windows Kits\8.1\include\winrt End of search list. "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\link.exe" -out:main.exe -nologo "C:\Users\markus\AppData\Local\Temp\main-366977.obj" Creating library main.lib and object main.exp main-366977.obj : error LNK2019: unresolved external symbol ___mulodi4 referenced in function _main main.exe : fatal error LNK1120: 1 unresolved externals clang-cl.exe: error: linker command failed with exit code 1120 (use -v to see invocation)
c:\build>