allwpilib/build.gradle

import org.apache.tools.ant.taskdefs.condition.Os

// This regex matches either a Windows or Unix style file separator, then the lib part of the library,
// then the name of the library itself, and finally the .so extension at the end. The name of the library
// is in the libName capture group, which is extracted and used for the linker flags
def libPattern = /.*((\\/|\\).*)+lib(?<libName>.+).so$/
def niLibraryArgs = []
def wpiLibraryArgs = []
def niLibraryPath = file('ni-libraries').path

// The NI Library tree includes all non-wpi libraries, which is everything that doesn't have libwpi in the name
def niLibraryTree = fileTree(niLibraryPath)
niLibraryTree.include '*.so'
niLibraryTree.exclude '*libwpi*.so'

// This adds all linker flags to the list of ni library linker flags
niLibraryTree.each { lib ->
    def nameMatcher = (lib.path =~ libPattern)
    if (nameMatcher[0].size() > 1) {
        def name = nameMatcher.group('libName')
        niLibraryArgs << '-l' + name
    }
}

// The WPI libraries are libraries in the ni-libraries folder that have libwpi in their names
def wpiLibraryTree = fileTree(niLibraryPath)
wpiLibraryTree.include '*libwpi*.so'

// This adds all linker flags to the list of wpi library linker flags
wpiLibraryTree.each { lib ->
    def nameMatcher = (lib.path =~ libPattern)
    if (nameMatcher[0].size() > 1) {
        def name = nameMatcher[0][1]
        wpiLibraryArgs << '-l' + name
    }
}

// Shells out to maven for generates the eclipse plugins.
// TODO: Get gradle to build this natively, rather than relying on maven. A plugin exists to do this, called Wuff, but this needs more investigation
// https://github.com/akhikhl/wuff
task eclipsePlugins(type: Exec) {
    description = 'Executes the maven build of the eclipse plugins'
    group = 'WPILib'
    workingDir 'eclipse-plugins'
    if (Os.isFamily(Os.FAMILY_WINDOWS)) {
        executable 'mvn.bat'
    } else {
        executable 'mvn'
    }
    args 'package'
}

// Rather than a normal clean, which executes whenever the clean task is run, this must be manually invoked. This
// is because the maven processes is very verbose and takes a long time, checking all of the eclipse repositories
task cleanEclipsePlugins(type: Exec) {
    description = 'Cleans the maven build of the eclipse plugins'
    group = 'WPILib'
    workingDir 'eclipse-plugins'
    if (Os.isFamily(Os.FAMILY_WINDOWS)) {
        executable 'mvn.bat'
    } else {
        executable 'mvn'
    }
    args 'clean'
}

subprojects {
    apply plugin: 'eclipse'
    apply plugin: 'idea'
    repositories {
        mavenCentral()
        mavenLocal()
    }

    // Disables doclint in java 8.
    if (JavaVersion.current().isJava8Compatible()) {
        allprojects {
            tasks.withType(Javadoc) {
                options.addStringOption('Xdoclint:none', '-quiet')
            }
        }
    }

    // Make sure that all maven publishing routines are run before the maven process starts
    plugins.withType(MavenPublishPlugin).whenPluginAdded {
        eclipsePlugins.dependsOn publishToMavenLocal
    }

    plugins.withType(CppPlugin).whenPluginAdded {
        model {
            buildTypes {
                debug
            }
            // Adds a custom toolchain for our compiler prefix and options
            toolChains {
                gcc(Gcc) {
                    target('arm') {
                        // We use a custom-built cross compiler with the prefix arm-frc-linux-gnueabi-<util name>
                        // If this ever changes, the prefix will need to be changed here
                        def compilerPrefix = 'arm-frc-linux-gnueabi-'
                        cppCompiler.executable = compilerPrefix + cppCompiler.executable
                        linker.executable = compilerPrefix + linker.executable
                        assembler.executable = compilerPrefix + assembler.executable
                        // Gradle auto-adds the -m32 argument to the linker and compiler. Our compiler only supports
                        // arm, and doesn't understand this flag, so it is removed from both
                        cppCompiler.withArguments { args ->
                            args << '-std=c++1y' << '-Wformat=2' << '-Wall' << '-Wextra' << '-Werror' << '-pedantic'
                            args << '-Wno-psabi' << '-Wno-unused-parameter' << '-fPIC' << '-O0' << '-g3' << '-rdynamic'
                            args.remove('-m32')
                        }
                        linker.withArguments { args ->
                            args << '-rdynamic'
                            args.remove('-m32')
                        }
                        staticLibArchiver.executable = compilerPrefix + staticLibArchiver.executable
                    }
                }
                // Workaround for OS X. Macs for some reason want to use Xcode's gcc
                // (which just wraps Clang), so we have to explicitly make it so 
                // that trying to compile with Clang will call gcc instead
                macGcc(Clang) {
                    target('arm') {
                        // We use a custom-built cross compiler with the prefix arm-frc-linux-gnueabi-<util name>
                        // If this ever changes, the prefix will need to be changed here
                        def compilerPrefix = 'arm-frc-linux-gnueabi-'
                        cppCompiler.executable = compilerPrefix + 'g++'
                        linker.executable = compilerPrefix + 'g++'
                        assembler.executable = compilerPrefix + 'gcc'
                        // Gradle auto-adds the -m32 argument to the linker and compiler. Our compiler only supports
                        // arm, and doesn't understand this flag, so it is removed from both
                        cppCompiler.withArguments { args ->
                            args << '-std=c++1y' << '-Wformat=2' << '-Wall' << '-Wextra' << '-Werror' << '-pedantic'
                            args << '-Wno-psabi' << '-Wno-unused-parameter' << '-fPIC' << '-O0' << '-g3' << '-rdynamic'
                            args.remove('-m32')
                        }
                        linker.withArguments { args ->
                            args << '-rdynamic'
                            args.remove('-m32')
                        }
                        staticLibArchiver.executable = compilerPrefix + staticLibArchiver.executable
                    }
                }
            }

            // The only platform is arm linux
            platforms {
                arm {
                    architecture 'arm'
                    operatingSystem 'linux'
                }
            }
        }

        // This task adds the appropriate linker flags for the NI libraries
        task addNiLibraryLinks() {
            description = 'Adds the linker flags for the NI libraries in the ni-library folders'
            group = 'WPILib'
            doLast {
                binaries.all {
                    tasks.withType(CppCompile) {
                        linker.args << '-L' + niLibraryPath
                        linker.args.addAll(niLibraryArgs)
                    }
                }
                model {
                    repositories {
                        libs(PrebuiltLibraries) { libs ->
                            // Loops through all .so files (except files matching *libwpi*.so) in ../ni-libraries
                            // and includes them for linking
                            niLibraryTree.each { niLib ->
                                libs.create(niLib) {
                                    binaries.withType(SharedLibraryBinary) {
                                        sharedLibraryFile = file(niLib.path)
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        // This task adds the appropriate linker flags for the WPI libraries
        task addWpiLibraryLinks() {
            description = 'Adds the linker flags for the WPI libraries in the ni-library folders'
            group = 'WPILib'
            doLast {
                binaries.all {
                    linker.args.addAll(wpiLibraryArgs)
                }
                model {
                    repositories {
                        libs(PrebuiltLibraries) { libs ->
                            // Loops through all libwpi*.so files in ../ni-libraries and includes them for linking
                            wpiLibraryTree.each { niLib ->
                                libs.create(niLib) {
                                    binaries.withType(SharedLibraryBinary) {
                                        sharedLibraryFile = file(niLib.path)
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        // Whenever we add the WPI library links, we'll also need the ni libraries, so set up that dependency
        addWpiLibraryLinks.dependsOn addNiLibraryLinks
    }
}