LSQUIC Build Issue

[mhmdreda99]

Problem

When building the LSQUIC project, users encountered linking errors related to C++ symbols from BoringSSL. The main issues were:

1. The project was configured to use only C, but BoringSSL requires C++ support.
2. The linker couldn't find certain C++ symbols, indicating a mismatch between the BoringSSL library and the LSQUIC project settings.

Solution

The solution involved several steps to properly integrate BoringSSL with LSQUIC:

1. Modified the CMakeLists.txt to include C++ support:

   • Changed PROJECT(lsquic C) to PROJECT(lsquic C CXX)

2. Added the C++ standard library to the linker flags:

   • Modified the LIBS variable in CMakeLists.txt to include -lstdc++

3. Ensured correct paths to BoringSSL were provided to CMake:

   cmake -DBORINGSSL_DIR=/path/to/boringssl \
         -DBORINGSSL_INCLUDE=/path/to/boringssl/include \
         -DBORINGSSL_LIB_ssl=/path/to/boringssl/build/ssl/libssl.a \
         -DBORINGSSL_LIB_crypto=/path/toboringssl/build/crypto/libcrypto.a \
         ..
   

4. If necessary, rebuilt BoringSSL with compatible compiler settings:

   cd /path/to/boringssl
   rm -rf build
   mkdir build
   cd build
   cmake -DCMAKE_BUILD_TYPE=Release ..
   make
   

Steps to Build LSQUIC

1. Ensure BoringSSL is properly built and its path is known.
2. Clean the LSQUIC build directory:

   cd  /path/to/lsquic/build
   rm -rf *
   

3. Run CMake with the correct BoringSSL paths:

   cmake -DBORINGSSL_DIR=/path/to/boringssl \
         -DBORINGSSL_INCLUDE=/path/to/boringssl/include \
         -DBORINGSSL_LIB_ssl=/path/to/boringssl/build/ssl/libssl.a \
         -DBORINGSSL_LIB_crypto=/path/to/boringssl/build/crypto/libcrypto.a \
         ..
   

4. Build the project:

   make
   

[flipkickmedia]

This needs merging. The BORINGSSL env var is a bad way to provide the locations of boringssl since the include dir remains with the source and the libraries are in different paths. Providing them seperately like this is a far better way IMO. Also adding the CXX to the project type and adding stdc++ on line 272 of CMakeLists.txt SET(LIBS lsquic ${BORINGSSL_LIB_ssl} ${BORINGSSL_LIB_crypto} ${ZLIB_LIB} ${LIBS} stdc++) got rid of the errors when linking to boringssl.