rippled/BUILD.md

⚠️ WARNING ⚠️
These instructions assume you have a C++ development environment ready with Git, Python, Conan, CMake, and a C++ compiler. For help setting one up on Linux, macOS, or Windows, see this guide.

These instructions also assume a basic familiarity with Conan and CMake. If you are unfamiliar with Conan, you can read our crash course or the official Getting Started walkthrough.

Branches

For a stable release, choose the master branch or one of the tagged releases.

git checkout master

For the latest release candidate, choose the release branch.

git checkout release

For the latest set of untested features, or to contribute, choose the develop branch.

git checkout develop

Minimum Requirements

See System Requirements.

Building rippled generally requires git, Python, Conan, CMake, and a C++ compiler. Some guidance on setting up such a C++ development environment can be found here.

• Python 3.7
• Conan 1.55
• CMake 3.16

rippled is written in the C++20 dialect and includes the <concepts> header. The minimum compiler versions required are:

Compiler	Version
GCC	10
Clang	13
Apple Clang	13.1.6
MSVC	19.23

Linux

The Ubuntu operating system has received the highest level of quality assurance, testing, and support.

Here are sample instructions for setting up a C++ development environment on Linux.

Mac

Many rippled engineers use macOS for development.

Here are sample instructions for setting up a C++ development environment on macOS.

Windows

Windows is not recommended for production use at this time.

• Additionally, 32-bit Windows development is not supported.
• Visual Studio 2022 is not yet supported.
  • rippled generally requires Boost 1.77, which Conan cannot build with VS 2022.
  • Until rippled is updated for compatibility with later versions of Boost, Windows developers may need to use Visual Studio 2019.

Steps

Set Up Conan

After you have a C++ development environment ready with Git, Python, Conan, CMake, and a C++ compiler, you may need to set up your Conan profile.

These instructions assume a basic familiarity with Conan and CMake.

If you are unfamiliar with Conan, then please read this crash course or the official Getting Started walkthrough.

You'll need at least one Conan profile:

conan profile new default --detect

Update the compiler settings:

conan profile update settings.compiler.cppstd=20 default

Linux developers will commonly have a default Conan profile that compiles with GCC and links with libstdc++. If you are linking with libstdc++ (see profile setting compiler.libcxx), then you will need to choose the libstdc++11 ABI:

conan profile update settings.compiler.libcxx=libstdc++11 default

Windows developers may need to use the x64 native build tools. An easy way to do that is to run the shortcut "x64 Native Tools Command Prompt" for the version of Visual Studio that you have installed.

Windows developers must also build rippled and its dependencies for the x64 architecture:

conan profile update settings.arch=x86_64 default

Multiple compilers

When /usr/bin/g++ exists on a platform, it is the default cpp compiler. This default works for some users.

However, if this compiler cannot build rippled or its dependencies, then you can install another compiler and set Conan and CMake to use it. Update the conf.tools.build:compiler_executables setting in order to set the correct variables (CMAKE_<LANG>_COMPILER) in the generated CMake toolchain file. For example, on Ubuntu 20, you may have gcc at /usr/bin/gcc and g++ at /usr/bin/g++; if that is the case, you can select those compilers with:

conan profile update 'conf.tools.build:compiler_executables={"c": "/usr/bin/gcc", "cpp": "/usr/bin/g++"}' default

Replace /usr/bin/gcc and /usr/bin/g++ with paths to the desired compilers.

It should choose the compiler for dependencies as well, but not all of them have a Conan recipe that respects this setting (yet). For the rest, you can set these environment variables. Replace <path> with paths to the desired compilers:

• conan profile update env.CC=<path> default
• conan profile update env.CXX=<path> default

Export our Conan recipe for Snappy. It does not explicitly link the C++ standard library, which allows you to statically link it with GCC, if you want.

conan export external/snappy snappy/1.1.10@

Export our Conan recipe for SOCI. It patches their CMake to correctly import its dependencies.

conan export external/soci soci/4.0.3@

Build and Test

1. Create a build directory and move into it.

   mkdir .build
   cd .build
   

   You can use any directory name. Conan treats your working directory as an install folder and generates files with implementation details. You don't need to worry about these files, but make sure to change your working directory to your build directory before calling Conan.

   Note: You can specify a directory for the installation files by adding the install-folder or -if option to every conan install command in the next step.

2. Generate CMake files for every configuration you want to build.

   conan install .. --output-folder . --build missing --settings build_type=Release
   conan install .. --output-folder . --build missing --settings build_type=Debug
   

   For a single-configuration generator, e.g. Unix Makefiles or Ninja, you only need to run this command once. For a multi-configuration generator, e.g. Visual Studio, you may want to run it more than once.

   Each of these commands should also have a different build_type setting. A second command with the same build_type setting will overwrite the files generated by the first. You can pass the build type on the command line with --settings build_type=$BUILD_TYPE or in the profile itself, under the section [settings] with the key build_type.

   If you are using a Microsoft Visual C++ compiler, then you will need to ensure consistency between the build_type setting and the compiler.runtime setting.

   When build_type is Release, compiler.runtime should be MT.

   When build_type is Debug, compiler.runtime should be MTd.

   conan install .. --output-folder . --build missing --settings build_type=Release --settings compiler.runtime=MT
   conan install .. --output-folder . --build missing --settings build_type=Debug --settings compiler.runtime=MTd
   

3. Configure CMake and pass the toolchain file generated by Conan, located at $OUTPUT_FOLDER/build/generators/conan_toolchain.cmake.

   Single-config generators:

   cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake -DCMAKE_BUILD_TYPE=Release ..
   

   Pass the CMake variable CMAKE_BUILD_TYPE and make sure it matches the build_type setting you chose in the previous step.

   Multi-config gnerators:

   cmake -DCMAKE_TOOLCHAIN_FILE:FILEPATH=build/generators/conan_toolchain.cmake ..
   

   Note: You can pass build options for rippled in this step.

4. Build rippled.

   For a single-configuration generator, it will build whatever configuration you passed for CMAKE_BUILD_TYPE. For a multi-configuration generator, you must pass the option --config to select the build configuration.

   Single-config generators:

   cmake --build .
   

   Multi-config generators:

   cmake --build . --config Release
   cmake --build . --config Debug
   

5. Test rippled.

   Single-config generators:

   ./rippled --unittest
   

   Multi-config generators:

   ./Release/rippled --unittest
   ./Debug/rippled --unittest
   

   The location of rippled in your build directory depends on your CMake generator. Pass --help to see the rest of the command line options.

Options

Option	Default Value	Description
assert	OFF	Enable assertions.
reporting	OFF	Build the reporting mode feature.
tests	ON	Build tests.
unity	ON	Configure a unity build.
san	N/A	Enable a sanitizer with Clang. Choices are thread and address.

Unity builds may be faster for the first build (at the cost of much more memory) since they concatenate sources into fewer translation units. Non-unity builds may be faster for incremental builds, and can be helpful for detecting #include omissions.

Troubleshooting

Conan

After any updates or changes to dependencies, you may need to do the following:

1. Remove your build directory.
2. Remove the Conan cache:

   rm -rf ~/.conan/data
   

3. Re-run conan install.

no std::result_of

If your compiler version is recent enough to have removed std::result_of as part of C++20, e.g. Apple Clang 15.0, then you might need to add a preprocessor definition to your build.

conan profile update 'options.boost:extra_b2_flags="define=BOOST_ASIO_HAS_STD_INVOKE_RESULT"' default
conan profile update 'env.CFLAGS="-DBOOST_ASIO_HAS_STD_INVOKE_RESULT"' default
conan profile update 'env.CXXFLAGS="-DBOOST_ASIO_HAS_STD_INVOKE_RESULT"' default
conan profile update 'conf.tools.build:cflags+=["-DBOOST_ASIO_HAS_STD_INVOKE_RESULT"]' default
conan profile update 'conf.tools.build:cxxflags+=["-DBOOST_ASIO_HAS_STD_INVOKE_RESULT"]' default

call to 'async_teardown' is ambiguous

If you are compiling with an early version of Clang 16, then you might hit a regression when compiling C++20 that manifests as an error in a Boost header. You can workaround it by adding this preprocessor definition:

conan profile update 'env.CXXFLAGS="-DBOOST_ASIO_DISABLE_CONCEPTS"' default
conan profile update 'conf.tools.build:cxxflags+=["-DBOOST_ASIO_DISABLE_CONCEPTS"]' default

recompile with -fPIC

If you get a linker error suggesting that you recompile Boost with position-independent code, such as:

/usr/bin/ld.gold: error: /home/username/.conan/data/boost/1.77.0/_/_/package/.../lib/libboost_container.a(alloc_lib.o):
  requires unsupported dynamic reloc 11; recompile with -fPIC

Conan most likely downloaded a bad binary distribution of the dependency. This seems to be a bug in Conan just for Boost 1.77.0 compiled with GCC for Linux. The solution is to build the dependency locally by passing --build boost when calling conan install.

conan install --build boost ...

Add a Dependency

If you want to experiment with a new package, follow these steps:

1. Search for the package on Conan Center.
2. Modify conanfile.py:
   • Add a version of the package to the requires property.
   • Change any default options for the package by adding them to the default_options property (with syntax '$package:$option': $value).
3. Modify CMakeLists.txt:
   • Add a call to find_package($package REQUIRED).
   • Link a library from the package to the target ripple_libs (search for the existing call to target_link_libraries(ripple_libs INTERFACE ...)).
4. Start coding! Don't forget to include whatever headers you need from the package.