I’ve built LLVM 3.8 on POWER with gcc 5.2.1 version for one of our application. This application is built using -std=c++14 support.
Using this particular combination, I’m getting one error where one of the exported symbols from our application (for a function returning std::string which is built by gcc) is different than the one when compiled by clang 3.8.
I also tried to replicate this issue by using a small test application which has a function named GetString() returning std::string. When I compile this file using gcc 5.2, I see symbol name as “_Z9GetStringB5cxx11v” and when I compile the same file using clang++, I get symbol name as “_Z9GetStringv”.
In order to resolve this difference, I tried below things -
- gcc 5.2 with c++11 support has added this special behavior due to which symbol name contains B5cxx11. Hence, I tried building LLVM/clang with -std=c++14 support. But no luck.
- Even if I provide -std=c++14 while compiling this source file using clang++, the result remained same.
- I tried setting -D_GLIBCXX_USE_CXX11_ABI=0 flag while compiling my application using gcc. This approach atleast gave me some success. Symbols generated for my source file after using flag were same as that of clang++ (i.e. without B5cxx11). But later my application failed at linking step for some undefined references - some of the references were of the application itself and a few from dependent libraries. I wanted to know if I would also need to build my dependent libraries using this flag.
I need some guidance here as to how I can build LLVM/clang so that it also generates symbols same as that of gcc5.2. I can’t use any other version of gcc as I’ll need rebuild lot of other dependencies.
Kindly help me.