How to use cmake or link an example?

[marbx]

Hello, because the Debian 12 Boost package libboost-all-dev does not include Redis, I "bootstrapped" boost 1.84.0 with

mkdir -p /home/marbx/boost/install
./bootstrap.sh --prefix=/home/marbx/boost/install
./b2 install

I can compile and run a Boost coroutine example using

g++ -Wl,--verbose=99 -std=c++20  example.cpp\
    -I/home/marbx/boost/install/include\
    -L/home/marbx/boost/install/lib\
    -lboost_coroutine -lboost_context -lboost_system -lm -lxml2 -lssl -lcrypto

export LD_LIBRARY_PATH=/home/marbx/boost/install/lib

./a.out

When I try to run cmake, as described in the README,...

BOOST_ROOT=/home/marbx/boost/install    cmake --preset g++-11

... I get many errors:

CMake Error at CMakeLists.txt:83 (add_subdirectory):
  add_subdirectory given source "../system" which is not an existing
  directory.
CMake Error at CMakeLists.txt:83 (add_subdirectory):
  add_subdirectory given source "../assert" which is not an existing
  directory.
...snip...
-- Could NOT find Protobuf (missing: Protobuf_LIBRARIES Protobuf_INCLUDE_DIR)
-- Configuring incomplete, errors occurred!

When I try to compile the Redis cpp17_intro example using...

g++ -Wl,--verbose=99 -std=c++17 example/cpp17_intro.cpp\
    -I/home/marbx/boost/install/include\
    -L/home/marbx/boost/install/lib\
    -lboost_thread -lssl -lcrypto -lm -lxml2 -lboost_coroutine -lboost_context -lboost_system

... I get many linker errors:

undefined reference to `boost::redis::connection::connection(boost::asio::io_context&, boost::asio::ssl::context_base::method, unsigned long)'
undefined reference to `boost::redis::connection::cancel(boost::redis::operation)'
...snip...
undefined reference to `boost::redis::resp3::boost_redis_to_bulk
collect2: error: ld returned 1 exit status

It seems I must specify a library, but there is no library called *redis* under /home/marbx/boost/install/lib/

What am I missing? Thanks

P.S. I corrected the g++ calls because they formerly used libraries from /usr/lib/*

[marbx]

cancel is defined in connection.hpp, a header only file. There is no need for a library. The problem is that connection.hpp is not read, so the linker must assume it is in a library.

g++ -H shows that compiler reads 5 redis related files, namely:

/home/marbx/boost/install/include/boost/redis/logger.hpp
/home/marbx/boost/install/include/boost/redis/detail/connector.hpp
/home/marbx/boost/install/include/boost/redis/detail/resolver.hpp
/home/marbx/boost/install/include/boost/redis/detail/handshaker.hpp
/home/marbx/boost/install/include/boost/redis/usage.hpp

So the question is why the compiler does not read

/home/marbx/boost/install/include/boost/redis/connection.hpp 

File permissions are regular

[mzimbres]

Hi, there are some problems building with cmake in the master branch. I have made some fixes in the develop though. This should work

# Clone the superproject (perhaps using shallow copies)
$ git clone --recurse-submodules https://github.com/boostorg/boost

# Checkout the develop branch
$ git submodule foreach --recursive git checkout develop

# Do an out of source build
$ mkir build
$ cmake ../boostorg/libs/redis
$ cmake --build . --target cpp20_intro

Let me know if this works for you.

[mzimbres]

cancel is defined in connection.hpp, a header only file. There is no need for a library. The problem is that connection.hpp is not read, so the linker must assume it is in a library.

You need to build the library yourself by including #include <boost/redis/src.hpp> in one cpp file, it can be the one where you define the main function.

[marbx]

Adding #include <boost/redis/src.hpp> to example/cpp17_intro.cpp results in 0 errors and a nice and cozy PING: Hello world :-)

Excellent!

Thank you a lot. Looking forward to continue from here, and to look into cloning the superproject, too.

Closing the issue, because the README already contains the advise. I just overlooked it.

[marbx]

Hi, there are some problems building with cmake in the master branch. I have made some fixes in the develop though. This should work

# Clone the superproject (perhaps using shallow copies)
$ git clone --recurse-submodules https://github.com/boostorg/boost

# Checkout the develop branch
$ git submodule foreach --recursive git checkout develop

# Do an out of source build
$ mkir build
$ cmake ../boostorg/libs/redis
$ cmake --build . --target cpp20_intro

Let me know if this works for you.

@mzimbres , yes, this worked out fine and I executed

$ example/cpp20_intro 
PING: Hello world

I like this out-of-source-build path, I now only have to better understand cmake :-)