Z3's CMake build system

CMake is a "meta build system" that reads a description of the project written in the CMakeLists.txt files and emits a build system for that project of your choice using one of CMake's "generators". This allows CMake to support many different platforms and build tools. You can run cmake --help to see the list of supported "generators" on your platform. Example generators include "UNIX Makefiles" and "Visual Studio 12 2013".

Getting started

Fixing a polluted source tree

If you have never used the python build system you can skip this step.

The existing Python build system creates generated source files in the source tree. The CMake build system will refuse to work if it detects this so you need to clean your source tree first.

To do this run the following in the root of the repository

git clean -nx src

This will list everything that will be removed. If you are happy with this then run.

git clean -fx src

which will remove the generated source files.

Unix Makefiles

Run the following in the top level directory of the Z3 repository.

mkdir build
cd build
cmake -G "Unix Makefiles" ../
make -j4 # Replace 4 with an appropriate number

Note that on some platforms "Unix Makefiles" is the default generator so on those platforms you don't need to pass -G "Unix Makefiles" command line option to cmake.

Note there is nothing special about the build directory name here. You can call it whatever you like.

Note the "Unix Makefile" generator is a "single" configuration generator which means you pick the build type (e.g. Debug, Release) when you invoke CMake. You can set the build type by passing it to the cmake invocation like so:

cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release ../

See the section on "Build Types" for the different CMake build types.

If you wish to use a different compiler set the CXX and CC environment variables passed to cmake. This must be done at the very first invocation to cmake in the build directory because once configuration has happened the compiler is fixed. If you want to use a different compiler to the one you have already configured you either need to make a new build directory or delete the contents of the current build directory and start again.

For example to use clang the cmake line would be

CC=clang CXX=clang++ cmake ../

Note that CMake build will detect the target architecture that compiler is set up to build for and the generated build system will build for that architecture. If there is a way to tell your compiler to build for a different architecture via compiler flags then you can set the CFLAGS and CXXFLAGS environment variables to have the build target that architecture.

For example if you are on a x86_64 machine and you want to do a 32-bit build and have a multilib version of GCC you can run cmake like this

CFLAGS="-m32" CXXFLAGS="-m32" CC=gcc CXX=g++ cmake ../

Note like with the CC and CXX flags this must be done on the very first invocation to CMake in the build directory.

Ninja

Ninja is a simple build system that is built for speed. It can be significantly faster than "UNIX Makefile"s because it is not a recursive build system and thus doesn't create a new process everytime it traverses into a directory. Ninja is particularly appropriate if you want fast incremental building.

Basic usage is as follows:

mkdir build
cd build
cmake -G "Ninja" ../
ninja

Note the discussion of the CC, CXX, CFLAGS and CXXFLAGS for "Unix Makefiles" also applies here.

Note also that like the "Unix Makefiles" generator, the "Ninja" generator is a single configuration generator so you pick the build type when you invoke cmake by passing CMAKE_BUILD_TYPE=<build_type> to cmake. See the section on "Build Types".

Note that Ninja runs in parallel by default. Use the -j flag to change this.

Note that Ninja also runs on Windows. You just need to run cmake in an environment where the compiler can be found. If you have Visual Studio installed it typically ships with a "Developer Command Prompt Window" that you can use which has the environment variables setup for you.

NMake

NMake is a build system that ships with Visual Studio. You are advised to use Ninja instead which is significantly faster due to supporting concurrent builds. However CMake does support NMake if you wish to use it. Note that NMake is a single configuration generator so you must set CMAKE_BUILD_TYPE to set the build type.

Basic usage:

1. Launch the "Developer Command Prompt Windows"
2. Change to the root of the Z3 repository

mkdir build
cd build
cmake -G "NMake Makefiles" ../
nmake

Visual Studio

Visual Studio 19 comes with integrated support for CMake. It suffices to open the (z3) folder where this file and the Z3 project CMakeLists.txt resides, and Visual Studio does the rest.

For legacy versions of Visual Studio a process is as follows: For the Visual Studio generators you need to know which version of Visual Studio you wish to use and also what architecture you want to build for.

We'll use the cmake-gui here as it is easier to pick the right generator but this can be scripted if need be.

Here are the basic steps:

1. Create an empty build directory
2. Start the cmake-gui program
3. Set "where is the source code" to the root of the Z3 project repository. You can do this by pressing the "Browse Source..." button and picking the directory.
4. Set "where to build the binaries" to the empty build directory you just created. You can do this by pressing the "Browse build..." button and picking the directory.
5. Press the "Configure" button
6. A window will appear asking you to pick the generator to use. Pick the generator that matches the version of Visual Studio you are using. Note also that some of the generator names contain Win64 (e.g. Visual Studio 12 2013 Win64) this indicates a x86 64-bit build. Generator names without this (e.g. Visual Studio 12 2013) are x86 32-bit build.
7. Press the "Finish" button and wait for CMake to finish it's first configure.
8. A set of configuration options will appear which will affect various aspects of the build. Change them as you desire. If you change a set of options press the "Configure" again. Additional options may appear when you do this.
9. When you have finished changing configuration options press the "Generate" button.
10. When generation is done close cmake-gui.
11. In the build directory open the generated Z3.sln solution file created by CMake with Visual Studio.
12. In Visual Studio pick the build type (e.g. Debug, Release) you want.
13. Click "BUILD > Build Solution".

Note that unlike the "Unix Makefile" and "Ninja" generators the Visual Studio generators are multi-configuration generators which means you don't set the build type when invoking CMake. Instead you set the build type inside Visual Studio. See the "Build Type" section for more information.

General workflow

The general workflow when using CMake is the following

1. Create a new build directory
2. Configure the project
3. Generate the build system
4. Invoke the build system to build the project

To perform steps 2 and 3 you can choose from three different tools

• cmake
• ccmake
• cmake-gui

cmake is a command line tool and is what you should use if you are writing a script to build Z3. This tool performs steps 1 and 2 in one go without user interaction. The ccmake and cmake-gui tools are more interactive and allow you to change various options. In both these tools the basic steps to follow are:

1. Configure.
2. Change any options you wish. Everytime you change a set of options You should configure again. This may cause new options to appear
3. Generate.

For information see https://cmake.org/runningcmake/

Note when invoking CMake you give it the path to the source directory. This is the top-level directory in the Z3 repository containing a CMakeLists.txt. That file should contain the line project(Z3 C CXX). If you give it a path deeper into the Z3 repository (e.g. the src directory) the configure step will fail.

Build Types

Several build types are supported.

• Release
• Debug
• RelWithDebInfo
• MinSizeRel

For the single configuration generators (e.g. "Unix Makefile" and "Ninja") you set the build type when invoking cmake by passing -DCMAKE_BUILD_TYPE=<build_type> where <build_type> is one of the build types specified above.

For multi-configuration generators (e.g. Visual Studio) you don't set the build type when invoking CMake and instead set the build type within Visual Studio itself.

Useful options

The following useful options can be passed to CMake whilst configuring.

• CMAKE_BUILD_TYPE - STRING. The build type to use. Only relevant for single configuration generators (e.g. "Unix Makefile" and "Ninja").
• CMAKE_INSTALL_BINDIR - STRING. The path to install z3 binaries (relative to CMAKE_INSTALL_PREFIX), e.g. bin.
• CMAKE_INSTALL_INCLUDEDIR - STRING. The path to install z3 include files (relative to CMAKE_INSTALL_PREFIX), e.g. include.
• CMAKE_INSTALL_LIBDIR - STRING. The path to install z3 libraries (relative to CMAKE_INSTALL_PREFIX), e.g. lib.
• CMAKE_INSTALL_PREFIX - STRING. The install prefix to use (e.g. /usr/local/).
• CMAKE_INSTALL_PKGCONFIGDIR - STRING. The path to install pkgconfig files.
• CMAKE_INSTALL_PYTHON_PKG_DIR - STRING. The path to install the z3 python bindings. This can be relative (to CMAKE_INSTALL_PREFIX) or absolute.
• CMAKE_INSTALL_Z3_CMAKE_PACKAGE_DIR - STRING. The path to install CMake package files (e.g. /usr/lib/cmake/z3).
• CMAKE_INSTALL_API_BINDINGS_DOC - STRING. The path to install documentation for API bindings.
• PYTHON_EXECUTABLE - STRING. The python executable to use during the build.
• Z3_ENABLE_TRACING_FOR_NON_DEBUG - BOOL. If set to TRUE enable tracing in non-debug builds, if set to FALSE disable tracing in non-debug builds. Note in debug builds tracing is always enabled.
• Z3_BUILD_LIBZ3_SHARED - BOOL. If set to TRUE build libz3 as a shared library otherwise build as a static library.
• Z3_ENABLE_EXAMPLE_TARGETS - BOOL. If set to TRUE add the build targets for building the API examples.
• Z3_USE_LIB_GMP - BOOL. If set to TRUE use the GNU multiple precision library. If set to FALSE use an internal implementation.
• Z3_BUILD_PYTHON_BINDINGS - BOOL. If set to TRUE then Z3's python bindings will be built.
• Z3_INSTALL_PYTHON_BINDINGS - BOOL. If set to TRUE and Z3_BUILD_PYTHON_BINDINGS is TRUE then running the install target will install Z3's Python bindings.
• Z3_BUILD_DOTNET_BINDINGS - BOOL. If set to TRUE then Z3's .NET bindings will be built.
• Z3_INSTALL_DOTNET_BINDINGS - BOOL. If set to TRUE and Z3_BUILD_DOTNET_BINDINGS is TRUE then running the install target will install Z3's .NET bindings.
• Z3_DOTNET_CSC_EXECUTABLE - STRING. The path to the C# compiler to use. Only relevant if Z3_BUILD_DOTNET_BINDINGS is set to TRUE.
• Z3_DOTNET_GACUTIL_EXECUTABLE - STRING. The path to the gacutil program to use. Only relevant if BUILD_DOTNET_BINDINGS is set to TRUE.
• Z3_BUILD_JAVA_BINDINGS - BOOL. If set to TRUE then Z3's Java bindings will be built.
• Z3_INSTALL_JAVA_BINDINGS - BOOL. If set to TRUE and Z3_BUILD_JAVA_BINDINGS is TRUE then running the install target will install Z3's Java bindings.
• Z3_JAVA_JAR_INSTALLDIR - STRING. The path to directory to install the Z3 Java .jar file. This path should be relative to CMAKE_INSTALL_PREFIX.
• Z3_JAVA_JNI_LIB_INSTALLDIRR - STRING. The path to directory to install the Z3 Java JNI bridge library. This path should be relative to CMAKE_INSTALL_PREFIX.
• Z3_INCLUDE_GIT_DESCRIBE - BOOL. If set to TRUE and the source tree of Z3 is a git repository then the output of git describe will be included in the build.
• Z3_INCLUDE_GIT_HASH - BOOL. If set to TRUE and the source tree of Z3 is a git repository then the git hash will be included in the build.
• Z3_BUILD_DOCUMENTATION - BOOL. If set to TRUE then documentation for the API bindings can be built by invoking the api_docs target.
• Z3_INSTALL_API_BINDINGS_DOCUMENTATION - BOOL. If set to TRUE and Z3_BUILD_DOCUMENTATION` is TRUEthen documentation for API bindings will be installed when running theinstall`` target.
• Z3_ALWAYS_BUILD_DOCS - BOOL. If set to TRUE and Z3_BUILD_DOCUMENTATION is TRUE then documentation for API bindings will always be built. Disabling this is useful for faster incremental builds. The documentation can be manually built by invoking the api_docs target.
• Z3_LINK_TIME_OPTIMIZATION - BOOL. If set to TRUE link time optimization will be enabled.
• Z3_ENABLE_CFI - BOOL. If set to TRUE will enable Control Flow Integrity security checks. This is only supported by MSVC and Clang and will fail on other compilers. This requires Z3_LINK_TIME_OPTIMIZATION to also be enabled.
• Z3_API_LOG_SYNC - BOOL. If set to TRUE will enable experimental API log sync feature.
• WARNINGS_AS_ERRORS - STRING. If set to TRUE compiler warnings will be treated as errors. If set to False compiler warnings will not be treated as errors. If set to SERIOUS_ONLY a subset of compiler warnings will be treated as errors.
• Z3_C_EXAMPLES_FORCE_CXX_LINKER - BOOL. If set to TRUE the C API examples will request that the C++ linker is used rather than the C linker.
• Z3_BUILD_EXECUTABLE - BOOL. If set to TRUE build the z3 executable. Defaults to TRUE unless z3 is being built as a submodule in which case it defaults to FALSE.
• Z3_BUILD_TEST_EXECUTABLES - BOOL. If set to TRUE build the z3 test executables. Defaults to TRUE unless z3 is being built as a submodule in which case it defaults to FALSE.
• Z3_SAVE_CLANG_OPTIMIZATION_RECORDS - BOOL. If set to TRUE saves Clang optimization records by setting the compiler flag -fsave-optimization-record.
• Z3_SINGLE_THREADED - BOOL. If set to TRUE compiles Z3 for single threaded mode.

On the command line these can be passed to cmake using the -D option. In ccmake and cmake-gui these can be set in the user interface.

Example

cmake -DCMAKE_BUILD_TYPE=Release -DZ3_ENABLE_TRACING_FOR_NON_DEBUG=FALSE ../

Z3 API Bindings

Z3 exposes various language bindings for its API. Below are some notes on building and/or installing these bindings when building Z3 with CMake.

Java bindings

The CMake build uses the FindJava and FindJNI cmake modules to detect the installation of Java. If CMake fails to find your installation of Java set the JAVA_HOME environment variable when invoking CMake so that it points at the correct location. For example

JAVA_HOME=/usr/lib/jvm/default cmake -DZ3_BUILD_JAVA_BINDINGS=ON ../

Note that the built .jar file is named com.microsoft.z3-VERSION.jar where VERSION is the Z3 version. Under non Windows systems a symbolic link named com.microsoft.z3.jar is provided. This symbolic link is not created when building under Windows.

Developer/packager notes

These notes are help developers and packagers of Z3.

Install/Uninstall

Install and uninstall targets are supported. Use CMAKE_INSTALL_PREFIX to set the install prefix. If you also need need to control which directories are used for install set the documented CMAKE_INSTALL_* options.

To install run

make install

To uninstall run

make uninstall

Note that DESTDIR is supported for staged installs.

To install

mkdir staged
make install DESTDIR=/full/path/to/staged/

to uninstall

make uninstall DESTDIR=/full/path/to/staged

The above also works for Ninja but DESTDIR must be an environment variable instead.

Examining invoked commands

If you are using the "UNIX Makefiles" generator and want to see exactly the commands that are being run you can pass VERBOSE=1 to make.

make VERBOSE=1

If you are using Ninja you can use the -v flag.

Additional targets

To see the list of targets run

make help

There are a few special targets:

• clean all the built targets in the current directory and below
• edit_cache will invoke one of the CMake tools (depending on which is available) to let you change configuration options.
• rebuild_cache will reinvoke cmake for the project.
• api_docs will build the documentation for the API bindings.

Setting build type specific flags

The build system supports single configuration and multi-configuration generators. This means it is not possible to know the build type at configure time and therefore ${CMAKE_BUILD_TYPE} should not be conditionally used to set compiler flags or definitions. Instead you should use Generator expressions which are evaluated by the generator.

For example

$<$<CONFIG:Debug>:Z3DEBUG>

If the build type at build time is Debug this evaluates to Z3DEBUG but evaluates to nothing for all other configurations. You can see examples of this in the CMakeLists.txt files.

File-globbing

It is tempting use file-globbing in CMakeLists.txt to find a set for files matching a pattern and use them as the sources to build a target. This however is a bad idea because it prevents CMake from knowing when it needs to rerun itself. This is why source file names are explicitly listed in the CMakeLists.txt so that when changes are made the source files used to build a target automatically triggers a rerun of CMake.

Long story short. Don't use file globbing.

Serious warning flags

By default the WARNINGS_AS_ERRORS flag is set to SERIOUS_ONLY which means some warnings will be treated as errors. These warnings are controlled by the relevant *_WARNINGS_AS_ERRORS list defined in cmake/compiler_warnings.cmake.

Additional warnings should only be added here if the warnings has no false positives.