INSTALL.md

   1 ## Grand Central Dispatch (GCD)
   2
   3 GCD is a concurrent programming framework first shipped with Mac OS X Snow
   4 Leopard.  This package is an open source bundling of libdispatch, the core
   5 user space library implementing GCD.  At the time of writing, support for
   6 the BSD kqueue API, and specifically extensions introduced in Mac OS X Snow
   7 Leopard and FreeBSD 9-CURRENT, are required to use libdispatch.  Linux is
   8 supported, but requires specific packages to be installed (see Linux
   9 section at the end of the file). Other systems are currently unsupported.
  10
  11 ### Configuring and installing libdispatch (general comments)
  12
  13 GCD is built using autoconf, automake, and libtool, and has a number of
  14 compile-time configuration options that should be reviewed before starting.
  15 An uncustomized install of the C-API to libdispatch requires:
  16
  17         sh autogen.sh
  18         ./configure
  19         make
  20         make install
  21
  22 libdispatch can be optionally built to include a Swift API. This requires a
  23 Swift toolchain to compile the Swift code in libdispatch and can be done
  24 in two possible scenarios.
  25
  26 If you are building your own Swift toolchain from source, then you should build
  27 libdispatch simply by giving additional arguments to swift/utils/build-script:
  28
  29     ./swift/utils/build-script --libdispatch -- --install-libdispatch
  30
  31 To build libdispatch using a pre-built Swift toolchain and install libdispatch
  32 into that toolchain (to allow that toolchain to compile Swift code containing
  33 "import Dispatch") requires:
  34
  35     sh autogen.sh
  36         ./configure --with-swift-toolchain=<PATH_TO_SWIFT_TOOLCHAIN> --prefix=<PATH_TO_SWIFT_TOOLCHAIN>
  37         make
  38         make install
  39
  40 Note that once libdispatch is installed into a Swift toolchain, that
  41 toolchain cannot be used to compile libdispatch again (you must 'make uninstall'
  42 libdispatch from the toolchain before using it to rebuild libdispatch).
  43
  44 You can also use the build-toolchain script to create a toolchain
  45 that includes libdispatch on Linux:
  46
  47 1. Add libdispatch and install-libdispatch lines to ./swift/utils/build-presets.ini under `[preset: buildbot_linux]` section, as following:
  48
  49     ```
  50     [preset: buildbot_linux]
  51     mixin-preset=mixin_linux_installation
  52     build-subdir=buildbot_linux
  53     lldb
  54     release
  55     test
  56     validation-test
  57     long-test
  58     libdispatch
  59     foundation
  60     lit-args=-v
  61     dash-dash
  62
  63     install-libdispatch
  64     install-foundation
  65     reconfigure
  66     ```
  67
  68 2. Run:
  69
  70     ```
  71     ./swift/utils/build-toolchain local.swift
  72     ```
  73
  74 Note that adding libdispatch in build-presets.ini is for Linux only as Swift on macOS platforms uses the system installed libdispatch, so its not required.
  75
  76 ### Building and installing on OS X
  77
  78 The following configure options may be of general interest:
  79
  80 `--with-apple-libpthread-source`
  81
  82 Specify the path to Apple's libpthread package, so that appropriate headers
  83         can be found and used.
  84
  85 `--with-apple-libplatform-source`
  86
  87 Specify the path to Apple's libplatform package, so that appropriate headers
  88         can be found and used.
  89
  90 `--with-apple-xnu-source`
  91
  92 Specify the path to Apple's XNU package, so that appropriate headers can be
  93         found and used.
  94
  95 `--with-blocks-runtime`
  96
  97 On systems where -fblocks is supported, specify an additional library path in which libBlocksRuntime can be found. This is not required on OS X, where the Blocks runtime is included in libSystem, but is required on FreeBSD.
  98
  99 The following options are likely to only be useful when building libdispatch on
 100 OS X as a replacement for /usr/lib/system/libdispatch.dylib:
 101
 102 `--disable-libdispatch-init-constructor`
 103
 104 Do not tag libdispatch's init routine as __constructor, in which case it must be run manually before libdispatch routines can be called. This is the default when building on OS X. For /usr/lib/system/libdispatch.dylib the init routine is called automatically during process start.
 105
 106 `--enable-apple-tsd-optimizations`
 107
 108 Use a non-portable allocation scheme for pthread per-thread data (TSD) keys when building libdispatch for /usr/lib/system on OS X.  This should not be used on other OS's, or on OS X when building a stand-alone library.
 109
 110 #### Typical configuration commands
 111
 112 The following command lines create the configuration required to build
 113 libdispatch for /usr/lib/system on OS X El Capitan:
 114
 115         clangpath=$(dirname `xcrun --find clang`)
 116         sudo mkdir -p "$clangpath/../local/lib/clang/enable_objc_gc"
 117         LIBTOOLIZE=glibtoolize sh autogen.sh
 118         cflags='-arch x86_64 -arch i386 -g -Os'
 119         ./configure CFLAGS="$cflags" OBJCFLAGS="$cflags" CXXFLAGS="$cflags" \
 120                 --prefix=/usr --libdir=/usr/lib/system --disable-static \
 121                 --enable-apple-tsd-optimizations \
 122                 --with-apple-libpthread-source=/path/to/10.11.0/libpthread-137.1.1 \
 123                 --with-apple-libplatform-source=/path/to/10.11.0/libplatform-73.1.1 \
 124                 --with-apple-xnu-source=/path/to/10.11.0/xnu-3247.1.106 \
 125         make check
 126
 127 ### Building and installing for FreeBSD
 128
 129 Typical configuration line for FreeBSD 8.x and 9.x to build libdispatch with
 130 clang and blocks support:
 131
 132         sh autogen.sh
 133         ./configure CC=clang --with-blocks-runtime=/usr/local/lib
 134         make check
 135
 136 ### Building and installing for Linux
 137
 138 Note that libdispatch development and testing is done only
 139 on Ubuntu; currently supported versions are 14.04, 15.10 and 16.04.
 140
 141 1. The first thing to do is install required packages:
 142
 143     `sudo apt-get install autoconf libtool pkg-config clang systemtap-sdt-dev libbsd-dev linux-libc-dev`
 144
 145     Note: compiling libdispatch requires clang 3.8 or better and
 146 the gold linker. If the default clang on your Ubuntu version is
 147 too old, see http://apt.llvm.org/ to install a newer version.
 148 On older Ubuntu releases, you may need to install binutils-gold
 149 to get the gold linker.
 150
 151 2. Build (as in the general instructions above)
 152
 153     ```
 154     sh autogen.sh
 155     ./configure
 156     make
 157     make install
 158     ```