vcmi/docs/developers/Conan.md

Conan Dependencies

Conan is a package manager for C/C++. We provide prebuilt binary dependencies for some platforms that are used by our CI, but they can also be consumed by users to build VCMI. However, it's not required to use only the prebuilt binaries: you can build them from source as well.

Supported platforms

The following platforms are supported and known to work, others might require changes to our conanfile.py or upstream recipes.

• macOS: x86_64 (Intel) - target 10.13 (High Sierra), arm64 (Apple Silicon) - target 11.0 (Big Sur)
• iOS: arm64 - target 12.0
• Windows: x86_64 and x86 fully supported with building from Linux
• Android: armeabi-v7a (32-bit ARM) - target 4.4 (API level 19), aarch64-v8a (64-bit ARM) - target 5.0 (API level 21)

Getting started

1. Install Conan. Currently we support only Conan v1, you can install it with pip like this: pip3 install 'conan<2.0'
2. Execute in terminal: conan profile new default --detect

Download dependencies

0. If your platform is not on the list of supported ones or you don't want to use our prebuilt binaries, you can still build dependencies from source or try consuming prebuilt binaries from the central Conan repository - ConanCenter. In this case skip to the next section directly.

1. Check if your build environment can use the prebuilt binaries: basically, that your compiler version (or Xcode major version) matches the information below. If you're unsure, simply advance to the next step.

   • macOS: libraries are built with Apple clang 14 (Xcode 14.2), should be consumable by Xcode / Xcode CLT 14.x and later (older library versions are also available for Xcode 13, see Releases in the respective repo)
   • iOS: libraries are built with Apple clang 14 (Xcode 14.2), should be consumable by Xcode 14.x and later (older library versions are also available for Xcode 13, see Releases in the respective repo)
   • Windows: libraries are built with x86_64-mingw-w64-gcc version 10 (which is available in repositories of Ubuntu 22.04)
   • Android: libraries are built with NDK r25c (25.2.9519653)

2. Download the binaries archive and unpack it to ~/.conan directory from https://github.com/vcmi/vcmi-dependencies/releases/latest

   • macOS: pick dependencies-mac-intel.txz if you have Intel Mac, otherwise - dependencies-mac-arm.txz
   • iOS: pick dependencies-ios.txz
   • Windows: currently only mingw is supported. Pick dependencies-mingw.tgz if you want x86_64, otherwise pick dependencies-mingw-32.tgz
   • Android: current limitation is that building works only on a macOS host due to Qt 5 for Android being compiled on macOS. Simply delete directory ~/.conan/data/qt/5.15.x/_/_/package (5.15.x is a placeholder) after unpacking the archive and build Qt from source. Alternatively, if you have (or are willing to build) Qt host tools for your platform, then simply replace those in the archive with yours and most probably it would work.

3. Only if you have Apple Silicon Mac and trying to build for macOS or iOS:

   1. Open file ~/.conan/data/qt/5.15.x/_/_/export/conanfile.py (5.15.x is a placeholder), search for string Designer (there should be only one match), comment this line and the one above it by inserting # in the beginning, and save the file.
   2. (optional) If you don't want to use Rosetta, follow instructions how to build Qt host tools for Apple Silicon, on step 3 copy them to ~/.conan/data/qt/5.15.x/_/_/package/SOME_HASH/bin (5.15.x and SOME_HASH are placeholders). Make sure not to copy qt.conf!

Generate CMake integration

Conan needs to generate CMake toolchain file to make dependencies available to CMake. See CMakeDeps and CMakeToolchain in the official documentation for details.

In terminal cd to the VCMI source directory and run the following command. Also check subsections for additional requirements on consuming prebuilt binaries.

conan install . \
  --install-folder=conan-generated \
  --no-imports \
  --build=never \
  --profile:build=default \
  --profile:host=CI/conan/PROFILE

The highlighted parts can be adjusted:

• conan-generated: directory (absolute or relative) where the generated files will appear. This value is used in CMake presets from VCMI, but you can actually use any directory and override it in your local CMake presets.
• never: use this value to avoid building any dependency from source. You can also use missing to build recipes, that are not present in your local cache, from source.
• CI/conan/PROFILE: if you want to consume our prebuilt binaries, PROFILE must be replaced with one of filenames from our Conan profiles directory (determining the right file should be straight-forward). Otherwise, either select one of our profiles or replace CI/conan/PROFILE with default (your default profile).
• note for Windows x86: use profile mingw32-linux.jinja for building instead of mingw64-linux.jinja

If you use --build=never and this command fails, then it means that you can't use prebuilt binaries out of the box. For example, try using --build=missing instead.

VCMI "recipe" also has some options that you can specify. For example, if you don't care about game videos, you can disable FFmpeg dependency by passing -o with_ffmpeg=False. If you only want to make release build, you can use GENERATE_ONLY_BUILT_CONFIG=1 environment variable to skip generating files for other configurations (our CI does this).

Note: you can find full reference of this command in the official documentation or by executing conan help install.

Using our prebuilt binaries for macOS/iOS

We use custom recipes for some libraries that are provided by the OS. You must additionally pass -o with_apple_system_libs=True for conan install to use them.

Using prebuilt binaries from ConanCenter

First, check if binaries for your platform are produced.

You must adjust the above conan install command:

1. Replace CI/conan/PROFILE with default.
2. Additionally pass -o default_options_of_requirements=True: this disables all custom options of our conanfile.py to match ConanCenter builds.

Building dependencies from source

This subsection describes platform specifics to build libraries from source properly.

Building for macOS/iOS

• To build Locale module of Boost in versions >= 1.81, you must use compiler.cppstd=11 Conan setting (our profiles already contain it). To use it with another profile, either add this setting to your host profile or pass -s compiler.cppstd=11 on the command line.
• If you wish to build dependencies against system libraries (like our prebuilt ones do), follow below instructions executing conan create for all directories. Don't forget to pass -o with_apple_system_libs=True to conan install afterwards.

Building for Android

Android has issues loading self-built shared zlib library because binary name is identical to the system one, so we enforce using the OS-provided library. To achieve that, follow below instructions, you only need zlib directory.

Also, Android requires a few Qt patches. They are needed only for specific use cases, so you may evaluate whether you need them. The patches can be found here. To apply selected patch(es), let Conan finish building dependencies first. Then cd to qtbase source directory (e.g. ~/.conan/data/qt/5.15.14/_/_/source/qt5/qtbase) and run patch -p1 < /path/to/patch for each patch file (on Windows you'll need some sort of GNU environment like Git Bash to access patch utility).

1. Safety measure for Xiaomi devices. It's unclear whether it's really needed, but without it I faced a crash once.
2. Fix running on Android 5.0-5.1 (API level 21-22).
3. Enable running on Android 4.4 (API level 19-20, 32-bit only). You must also apply one more patch, but you must cd to the package directory for that, e.g. ~/.conan/data/qt/5.15.14/_/_/package/SOME_HASH.

After applying patch(es):

1. cd to qtbase/src/android/jar in the build directory, e.g. ~/.conan/data/qt/5.15.14/_/_/build/SOME_HASH/build_folder/qtbase/src/android/jar.
2. Run make
3. Copy file qtbase/jar/QtAndroid.jar from the build directory to the package directory, e.g. ~/.conan/data/qt/5.15.14/_/_/package/SOME_HASH/jar.

Note: if you plan to build Qt from source again, then you don't need to perform the above After applying patch(es) steps after building.

Using recipes for system libraries

1. Clone/download https://github.com/kambala-decapitator/conan-system-libs
2. Execute conan create PACKAGE vcmi/CHANNEL, where PACKAGE is a directory path in that repository and CHANNEL is apple for macOS/iOS and android for Android. Do it for each library you need.
3. Now you can execute conan install to build all dependencies.

Configure project for building

You must pass the generated toolchain file to CMake invocation.

• if using custom CMake presets, just make sure to inherit our build-with-conan preset. If you store Conan generated files in a non-default directory, define the path to the generated toolchain in toolchainFile field (or CMAKE_TOOLCHAIN_FILE cache variable) or include CMake presets file generated by Conan.
• otherwise, if passing CMake options on the command line, use --toolchain option (available in CMake 3.21+) or CMAKE_TOOLCHAIN_FILE variable.

Examples

In these examples only the minimum required amount of options is passed to cmake invocation, you can pass additional ones as needed.

Use our prebuilt binaries to build for macOS x86_64 with Xcode

conan install . \
  --install-folder=conan-generated \
  --no-imports \
  --build=never \
  --profile:build=default \
  --profile:host=CI/conan/macos-intel \
  -o with_apple_system_libs=True

cmake -S . -B build -G Xcode \
  --toolchain conan-generated/conan_toolchain.cmake

Try to use binaries from ConanCenter for your platform

If you also want to build the missing binaries from source, use --build=missing instead of --build=never.

conan install . \
  --install-folder=~/my-dir \
  --no-imports \
  --build=never \
  --profile:build=default \
  --profile:host=default \
  -o default_options_of_requirements=True

cmake -S . -B build \
  -D CMAKE_TOOLCHAIN_FILE=~/my-dir/conan_toolchain.cmake

Use our prebuilt binaries to build for iOS arm64 device with custom preset

conan install . \
  --install-folder=~/my-dir \
  --no-imports \
  --build=never \
  --profile:build=default \
  --profile:host=CI/conan/ios-arm64 \
  -o with_apple_system_libs=True

cmake --preset ios-conan

CMakeUserPresets.json file:

{
    "version": 3,
    "cmakeMinimumRequired": {
        "major": 3,
        "minor": 21,
        "patch": 0
    },
    "configurePresets": [
        {
            "name": "ios-conan",
            "displayName": "iOS",
            "inherits": ["build-with-conan", "ios-device"],
            "toolchainFile": "~/my-dir/conan_toolchain.cmake",
            "cacheVariables": {
                "BUNDLE_IDENTIFIER_PREFIX": "com.YOUR-NAME",
                "CMAKE_XCODE_ATTRIBUTE_DEVELOPMENT_TEAM": "YOUR_TEAM_ID"
            }
        }
    ]
}

Build VCMI with all deps for 32-bit windows in Ubuntu 22.04 WSL

wsl --install
wsl --install -d Ubuntu
ubuntu

Next steps are identical both in WSL and in real Ubuntu 22.04

sudo pip3 install conan
sudo apt install cmake build-essential
sed -i 's/x86_64-w64-mingw32/i686-w64-mingw32/g' CI/mingw-ubuntu/before-install.sh
sed -i 's/x86-64/i686/g' CI/mingw-ubuntu/before-install.sh
sudo ./CI/mingw-ubuntu/before-install.sh
conan install . \
  --install-folder=conan-generated \
  --no-imports \
  --build=missing \
  --profile:build=default \
  --profile:host=CI/conan/mingw32-linux \
  -c tools.cmake.cmaketoolchain.presets:max_schema_version=2
cmake --preset windows-mingw-conan-linux
cmake --build --preset windows-mingw-conan-linux --target package

After that, you will have functional VCMI installer for 32-bit windows.