On Thu, 24 Apr 2025 10:06:05 -0700 (PDT) Jeremy Drake wrote: > On Thu, 24 Apr 2025, Takashi Yano via Cygwin-apps wrote: > > > Hi Jeremy, > > > > On Tue, 22 Apr 2025 15:50:52 +0900 > > To avoid this incompatibility, I tried to build llvm/clang without > > both 0005-use_cxx11_abi.patch and 0110-use_cxx11_abi.patch, and add > > -DCMAKE_CXX_STANDARD=20 > > instead. It makes llvm/clang be built successfully. > > > > Then, the linkage between objects compiled by g++ and clang++ succeeded. > > $ g++ -c b.cc -o b.o > > $ clang++ -std=c++14 -c a.cc -o a.o > > $ clang++ a.o b.o > > $ ./a.exe > > Received string: Processed: Hello, World! > > $ > > > > Without -std=c++14, an error occurs in linking. > > > > I also tested dll like: > > $ g++ -shared b.cc -o b.dll > > $ clang++ -c a.cc -o a.o > > $ clang++ a.o b.dll > > $ ./a.exe > > Received string: Processed: Hello, World! > > $ > > and it scceeded as well. > > > > Isn't this better than mixed ABI problem, is it? > > > > I'm still not sure why the llvm-min-tblgen.exe crashes, so > > there may be still have problems even with this hack. > > https://github.com/llvm/llvm-project/issues/135910
Thanks! https://github.com/llvm/llvm-project/issues/135910#issuecomment-2822518681 is very helpfull to understand what is happening. Then, the following error should be due to the same problem: $ g++ -c b.cc -o b.o $ clang++ -c a.cc -o a.o $ clang++ a.o b.o /usr/lib/gcc/x86_64-pc-cygwin/12/../../../../x86_64-pc-cygwin/bin/ld: b.o:b.cc:(.text$_ZNSt11char_traitsIcE6lengthEPKc[_ZNSt11char_traitsIcE6lengthEPKc]+0x0): multiple definition of `std::char_traits<char>::length(char const*)'; a.o:a.cc:(.text[_ZNSt11char_traitsIcE6lengthEPKc]+0x0): first defined here collect2: error: ld returned 1 exit status clang++: error: linker (via gcc) command failed with exit code 1 (use -v to see invocation) $ Right? -- Takashi Yano <takashi.y...@nifty.ne.jp>
