Package: aim-build
AimA command line tool for building C++ projects.IntroductionAim is an attempt to make building C++ projects from source as simple as possible while encouraging a modular approach to software development.Aim only requires atarget.pyfile which is used to specify the builds of your project. Each build specifies a
component of your project, like a static library, dynamic library, or an executable.Each target you aim to support requires its owntarget.pyfile. This is easier to explain with an example:+ Project
  + builds
    + linux-debug
      - target.py
    + linux-release
      - target.py
    + windows-debug
      - target.py
    + windows-release
      - target.py
  + src
    + ...Wherewindows/linuxanddebug/releasecompose to make make different targets.When running commands, you often need to specify the path to directory of the target.py file. For example:builds/windows-debugorbuilds/linux-release.
Do not addtarget.pyto the path.Aim supports:Windows withmsvcfrontend.Linux withgccfrontend.It should also be possible to use thegccfrontend on Windows when using GCC-like compilers but this hasn't been
tested.Updates(23/01/2022) CLI has changed again. Removed previous change. There is now aexeccommand that executes several
commands in one. For exampleaim exec <path> <build> clobber build run.(23/12/2021) CLI has changed.list,build,runandclobberare nowtargetcommands and are executed like so:aim target <path> build <name>instead ofaim build --target=<path> <name>. This is to make switching between
commands easier.Aim no longer uses thetomlfor thetargetfile format.targetfiles are now written in Python. The motivation
for this change is that it can be useful to access environment variables and to store properties, such as compiler flags,
as variables. To support this change, there is theutil/convert_toml.pyscript. To convert atomlfile, execute from
the aim root directory:poetry run python util\convert_toml.py <relative/path/to/target.toml>. The Python file will be
written to the same directory as thetarget.tomlfile.Getting StartedPrerequisitesAim requires the following dependencies:python- version 3.7 or above.ninjapoetry- for development onlylinux-debugtarget.pylinux-releasetarget.pyInstallationAim is apythonproject and is installed usingpip.pip install --user aim-buildUsingBasic usage:aim --help                                    # displays the help.
aim init --demo-files                         # creates src, include, lib directory and adds demo files.
aim list builds/linux-clang++-debug           # lists the builds in target.py
aim build builds/linux-clang++-debug <build>  # executes <build>.
aim clobber builds/linux-clang++-debug        # deletes all build artifacts.You can run executables directly or using theruncommand:./builds/clang++-linux-debug/<build-name>/<output-name>
aim run builds/clang++-linux-debug run <build-name>Target filesAtarget.pyfile describes a project and its build components.Begin by specifyingprojectRootwhich is the path from the target file to your source files. All relative paths
will be relative to this directory.The compiler frontend informs Aim how to construct the arguments for the compiler. Usegccfor GCC-like compilers andmsvcfor Microsoft cl-like compilers. Next specify thecompiler,archiver,flagsand anydefines.projectRoot = "../.."

compilerFrontend="gcc"
compiler = "clang++"
archiver = "ar"

flags = [
    "-std=c++17",
    "-O3",
    "-g",
    "-Wall",
]

# defines = [...] # Defines do not need the -D prefix.Next specify your builds. For each build you must specify thenameandbuildRule. Valid build rules arestaticLibrary,dynamicLibrary,executable,headerOnlyorlibraryReference. Atarget.pythat consists of a
dynamic or shared library, an application and a test executable looks like:builds = [
    {
        "name": "calculatorstatic",
        "buildRule": "staticLibrary",
        "outputName": "CalculatorStatic",
        "sourceFiles": ["lib/*.cpp"],
        "includePaths": [
            "include"
        ]
    },
    {
        "name": "calculatordynamic",
        "buildRule": "dynamicLibrary",
        "outputName": "CalculatorShared",
        "sourceFiles": ["lib/*.cpp"],
        "includePaths": [
            "include"
        ]
    },
    {
        "name": "calculatortests",
        "buildRule": "executable",
        "requires": ["calculatorstatic"],
        "outputName": "CalculatorTests",
        "sourceFiles": ["tests/*.cpp"],
        "includePaths": ["include"]
    },
    {
        "name": "calculatorapp",
        "buildRule": "executable",
        "requires": ["calculatordynamic"],
        "outputName": "CalculatorApp",
        "sourceFiles": ["src/*.cpp"],
        "includePaths": ["include"]
    }
]Other notes:Therequiresfield is important as it is how you specify the dependencies for a build. For example, if you create a static library named "myAwesomeLibrary", this can be used in other builds simply by specifyingrequires=["myAwesomeLibrary"].AheaderOnlybuild does not have anoutputNameorsourceFilesas it is not built. TheheaderOnlyrule is not essential and is mostly for convenience. If you have a header only library, repeating the include paths across several builds can be become repetitive. Instead, create aheaderOnlybuild to capture the include paths and use it in other builds by adding the rule to the buildsrequiresfield.AlibraryReferencedoes not havesourceFilesas it is not built. Like theheaderOnlyrule it is mostly for convience to reduce duplication. The primary use case is for capturing theincludePaths,libraryPathsandlibrariesof a third party library that you need to use in a build. AlibraryReferencecan then be used by other builds by adding it to a buildsrequiresfield.The fieldscompiler,flagsanddefinesare normally written at the top of the target file before the builds section. By default, all builds will use these fields i.e. they are global, but they can also be overridden by specifying them again in a build. Note that when these fields are specified specifically for a build, they completely replace the global definition; anyflagsordefinesthat you specify must be written out in full as they will not share any values with the global definition.Since target files are just python, you can have variables. However, since target files are validated with a schema, variables must be escaped with a leading underscore. For example_custom_defines = [...]is okay, butcustom_defines = [...]will cause a schema error.Supporting Multiple TargetsAim treats any build variation as its own unique build target with its own uniquetarget.py.A build target is some combination ofthingsthat affects the output binary such as:operating system (Windows, OSX, Gnu Linux)compiler (MSVC, GCC, Clang)build type (Release, Debug, Sanitized)etc.Each build target and correspondingtarget.pyfile must have its own directory ideally named using a unique
identifier that comprises the 'parts' that make up the build. For example,builds/linux-clang++-release/target.pyindicates that the target file describes a project that is areleasebuild, uses theclang++compiler and is for thelinuxoperating system.As an example, if you were developing an application for both Windows and Linux, you may end up with a build directory structure like the following:builds/linux-clang++-release/target.pybuilds/linux-clang++-debug/target.pybuilds/windows-clangcl-release/target.pybuilds/windows-clangcl-debug/target.pyNote: eachtarget.pyfile must be written out in full for each target that you need to support. There is no way for
target files to share information or to depend on another. While this leads to duplication between target files, it
makes them very explicit and makes debugging builds much easier.Advice Structuring ProjectsIf you structure your project/libraries as individual repositories then it may seem logical to nest dependencies inside
one another. For example, if library B depends on library A, then B needs a copy of A in order for it to be built.
So you may choose to nest the source of A inside B, perhaps using a git submodule.The problem comes when your dependency hierarchy becomes more complex. If library C also depends on A, and an application D
depends on B and C, you'll end up with multiple copies of library A which can become difficult to manage.You may need to use this approach, as it can be useful to build a library in isolation, however you should do so in such
a way where pulling the source for the dependencies is optional.The approach the author uses is to use a non-project-specific directory that includes all your projects directly below it
i.e. a "flat" structure. So rather than nesting dependencies you have:+ MyProjects
 + - LibA
 + - LibB
 + - LibC
 + - Application_1
 + - Application_2
 + - builds
 + - - App1
 + - - - linux-clang++-debug
 + - - - - target.pyThe flat structure has a single build directory and a single target file for each build target you need to support. This eliminates any
duplication and is easy to manage.Aimis flexible enough that you can add additional levels to the project structure
should you need to. For example, you may want to group all libraries under a libraries sub-directory. But the take-away message
is that you should notenforcenested dependencies as this leads to duplication.Developing AimAim is a Python project and uses thepoetrydependency manager. Seepoetry installationfor instructions.Once you have cloned the project, the virtual environment and dependencies can be installed by executing:poetry installDev InstallUnfortunately, unlikesetuptools, there is no means to do a 'dev install' using poetry. A dev install effectively generates
an application that internally references the active source files under development. This allows developers to test the application
without having to re-install the application after each change.In order to use a development version of Aim on the command line, is it recommended creating an alias. The alias needs to:add the Aim directory toPYTHONPATHto resolve import/module pathsexecute the main Aim script using the virtualenv created by poetryThere aredev-env.bashanddev-env.fishscripts that configure this for you in the root of the Aim project directory.
Note, these files must be sourced in order for them to work.