nt/INSTALL.MSYS

   1                     Building and Installing Emacs on MS-Windows
   2                           using the MSYS and MinGW tools
   3
   4   Copyright (C) 2013 Free Software Foundation, Inc.
   5   See the end of the file for license conditions.
   6
   7 The MSYS/MinGW build described here is supported on versions of
   8 Windows starting with Windows 2000 and newer.  Windows 9X are not
   9 supported (but the Emacs binary produced by this build will run on
  10 Windows 9X as well).
  11
  12 * For the brave (a.k.a. "impatient"):
  13
  14   For those who have a working MSYS/MinGW development environment and
  15   are comfortable with running Posix configure scripts, here are the
  16   concise instructions for configuring and building the native Windows
  17   binary of Emacs with these tools.
  18
  19   Do not use this recipe with Cygwin.  For building on Cygwin, use the
  20   normal installation instructions, ../INSTALL.
  21
  22   Do not use these instructions if you don't have MSYS installed; for
  23   that, see the file INSTALL in this directory.
  24
  25   0. Start the MSYS Bash window.  Everything else below is done from
  26      that window's Bash prompt.
  27
  28   0a. If you are building from the development trunk (as opposed to a
  29       release tarball), produce the configure script, by typing from
  30       the top-level Emacs source directory:
  31
  32       ./autogen.sh
  33
  34   1. If you want to build Emacs outside of the source tree
  35      (recommended), create the build directory and chdir there.
  36
  37   2. Invoke the MSYS-specific configure script:
  38
  39       - If you are building outside the source tree:
  40
  41         /PATH/TO/EMACS/SOURCE/TREE/nt/msysconfig.sh --prefix=PREFIX ...
  42
  43       - If you are building in-place, i.e. inside the source tree:
  44
  45         ./nt/msysconfig.sh --prefix=PREFIX ...
  46
  47      It is always preferable to use --prefix to configure Emacs for
  48      some specific location of its installed tree; the default
  49      /usr/local is not suitable for Windows (see the detailed
  50      instructions for the reasons).
  51
  52      You can pass other options to the configure script.  Here's a
  53      typical example (for an in-place debug build):
  54
  55        CPPFLAGS='-DGLYPH_DEBUG=1' CFLAGS='-O0 -g3' ./nt/msysconfig.sh --prefix=/d/usr/emacs --enable-checking
  56
  57   3. After the configure script finishes, it should display the
  58      resulting configuration.  After that, type
  59
  60        make
  61
  62      Use "make -j N" if your MSYS Make supports parallel execution;
  63      the build will take significantly less time in that case.  Here N
  64      is the number of simultaneous parallel jobs; use the number of
  65      the cores on your system.
  66
  67   4. Install the produced binaries:
  68
  69        make install
  70
  71      If you want the installation tree to go to a place that is
  72      different from the one specified by --prefix, say
  73
  74        make install prefix=/where/ever/you/want
  75
  76   That's it!
  77
  78   If these short instructions somehow fail, read the rest of this
  79   file.
  80
  81 * Installing MinGW and MSYS
  82
  83   Make sure you carefully read the following two sections in their
  84   entirety and install/configure the various packages as instructed.
  85   A correct installation makes all the rest almost trivial; a botched
  86   installation will likely make you miserable for quite some time.
  87
  88   There are two alternative to installing MinGW + MSYS: using the GUI
  89   installer, called mingw-get, provided by the MinGW project, or
  90   manual installation.  The next two sections describe each one of
  91   these.
  92
  93 ** Installing MinGW and MSYS using mingw-get
  94
  95   A nice installer, called mingw-get, is available for those who don't
  96   like to mess with manual installations.  You can download it from
  97   here:
  98
  99     https://sourceforge.net/projects/mingw/files/Installer/mingw-get/
 100
 101   (This installer only supports packages downloaded from the MinGW
 102   site; for the rest you will still need the manual method.)
 103
 104   After installing mingw-get, invoke it to install the packages that
 105   are already selected by default on the "Select Components" screen of
 106   its wizard.
 107
 108   After that, use "mingw-get install PACKAGE" to install the following
 109   additional packages:
 110
 111    . msys-base
 112    . mingw-developer-toolkit
 113
 114   (We recommend that you refrain from installing the MSYS Texinfo
 115   package, which is part of msys-base, because it might produce mixed
 116   EOL format when installing Info files.  Instead, install the MinGW
 117   port of Texinfo, see the ezwinports URL below.  To uninstall the
 118   MSYS Texinfo, after installing it as part of msys-base, invoke the
 119   command "mingw-get remove msys-texinfo".)
 120
 121   At this point, you should be ready to configure and build Emacs in
 122   its basic configuration.  Skip to the "Generating the configure
 123   script" section for the build instructions.  If you want to build it
 124   with image support and other optional libraries, read about the
 125   optional libraries near the end of this document, before you start
 126   the build.  Also, consider installing additional MinGW packages that
 127   are required/recommended, especially if you are building from the
 128   Bazaar repository, as described in the next section.
 129
 130 ** Installing MinGW and MSYS manually
 131
 132 *** MinGW
 133
 134   You will need to install the MinGW port of GCC and Binutils, and the
 135   MinGW runtime and Windows API distributions, to compile Emacs.  You
 136   can find these on the MinGW download/Base page:
 137
 138     https://sourceforge.net/projects/mingw/files/MinGW/Base/
 139
 140   In general, install the latest stable versions of the following
 141   MinGW packages from that page: gcc, binutils, mingw-rt, w32api.  You
 142   only need the 'bin' and the 'dll' tarballs of each of the above.
 143
 144   MinGW packages are distributed as .tar.lzma compressed archives.  To
 145   install the packages manually, we recommend to use the Windows port
 146   of the 'bsdtar' program to unpack the tarballs.  'bsdtar' is
 147   available as part of the 'libarchive' package from here:
 148
 149     http://sourceforge.net/projects/ezwinports/files/
 150
 151   The recommended place to install these packages is a single tree
 152   starting from some directory on a drive other than the system drive
 153   C:.  A typical example would be D:\usr, with D:\usr\bin holding the
 154   binaries and DLLs (should be added to your Path environment
 155   variable), D:\usr\include holding the include files, D:\usr\lib
 156   holding the static and import libraries, D:\usr\share holding docs,
 157   message catalogs, and package-specific subdirectories, etc.
 158
 159   Having all the headers and libraries in a single place will greatly
 160   reduce the number of -I and -L flags you will have to pass to the
 161   configure script (see below), as these files will be right where the
 162   compiler expects them.
 163
 164   We specifically do NOT recommend installing packages below
 165   "C:\Program Files" or "C:\Program Files (x86)".  These directories
 166   are protected on versions of Windows from Vista and on, and you will
 167   have difficulties updating and maintaining your installation later,
 168   due to UAC elevation prompts, file virtualization, etc.  You *have*
 169   been warned!
 170
 171   Additional MinGW packages are required/recommended, especially if
 172   you are building from the Bazaar repository:
 173
 174    . Texinfo (needed to produce the Info manuals when building from
 175      bzr, and for "make install")
 176
 177      Available from http://sourceforge.net/projects/ezwinports/files/.
 178
 179    . gzip (needed to compress files during "make install")
 180
 181      Available from http://gnuwin32.sourceforge.net/packages/gzip.htm.
 182
 183    . pkg-config (needed for building with some optional libraries,
 184      such as GnuTLS and libxml2)
 185
 186      Available from http://www.gtk.org/download/win32.php
 187
 188   Each package might list other packages as prerequisites on its
 189   download page (under "Runtime requirements"); download those as
 190   well.  (Using the mingw-get installer will fetch those prerequisites
 191   automatically for you.)  A missing prerequisite will manifest itself
 192   by the program failing to run and presenting a pop-up dialog that
 193   states the missing or incompatible DLL; be sure to find and install
 194   these missing DLLs.
 195
 196   Once you think you have MinGW installed, test the installation by
 197   building a trivial "hello, world!" program, and make sure that it
 198   builds without any error messages and the binary works when run.
 199
 200 *** MSYS
 201
 202   You will need a reasonably full MSYS installation.  MSYS is an
 203   environment needed to run the Posix configure scripts and the
 204   resulting Makefile's, in order to produce native Windows binaries
 205   using the MinGW compiler and runtime libraries.  Here's the list of
 206   MSYS packages that are required:
 207
 208    . All the packages from the MSYS Base distribution, listed here:
 209
 210      https://sourceforge.net/projects/mingw/files/MSYS/Base/
 211
 212    . Additional packages listed below, from the MSYS Extension
 213      distribution here:
 214
 215      https://sourceforge.net/projects/mingw/files/MSYS/Extension/
 216
 217       - flex
 218       - bison
 219       - m4
 220       - perl
 221       - mktemp
 222
 223      These should only be needed if you intend to build development
 224      versions of Emacs from the Bazaar repository.
 225
 226    . Additional packages (needed only if building from the Bazaar
 227      repository): Automake and Autoconf.  They are available from
 228      here:
 229
 230        http://sourceforge.net/projects/ezwinports/files/automake-1.11.6-msys-bin.zip/download
 231        http://sourceforge.net/projects/ezwinports/files/autoconf-2.65-msys-bin.zip/download
 232
 233   MSYS packages are distributed as .tar.lzma compressed archives.  To
 234   install the packages manually, we recommend to use the Windows port
 235   of the 'bsdtar' program, already mentioned above.
 236
 237   If/when you are confident in your MinGW/MSYS installation, and want
 238   to speed up the builds, we recommend installing a pre-release
 239   version of Make from here:
 240
 241      https://sourceforge.net/projects/mingwbuilds/files/external-binary-packages/
 242
 243   These are snapshot builds of many packages, but you only need
 244   make.exe from there.  The advantage of this make.exe is that it
 245   supports parallel builds, so you can use "make -j N" to considerably
 246   speed up your builds.
 247
 248   Several users reported that MSYS 1.0.18 causes Make to hang in
 249   parallel builds.  If you bump into this, we suggest to downgrade to
 250   MSYS 1.0.17, which doesn't have that problem.
 251
 252   For each of these packages, install the 'bin' and 'dll' tarballs of
 253   their latest stable releases.  If there's an 'ext' tarball (e.g.,
 254   msysCORE and Coreutils have it), download and install those as well.
 255
 256   Each package might list other packages as prerequisites on its
 257   download page (under "Runtime requirements"); download those as
 258   well.  (Using the mingw-get installer will fetch those prerequisites
 259   automatically for you.)  A missing prerequisite will manifest itself
 260   by the program failing to run and presenting a pop-up dialog that
 261   states the missing or incompatible DLL; be sure to find and install
 262   these missing DLLs.
 263
 264   MSYS packages should be installed in a separate tree from MinGW.
 265   For example, use D:\MSYS or D:\usr\MSYS as the top-level directory
 266   from which you unpack all of the MSYS packages.
 267
 268   Do NOT add the MSYS bin directory to your Windows Path!  Only the
 269   MinGW bin directory should be on Path.  When you install MSYS, it
 270   creates a shortcut on your desktop that invokes the MSYS Bash shell
 271   in a Command Prompt window; that shell is already set up so that the
 272   MSYS bin directory is on PATH ahead of any other directory.  Thus,
 273   Bash will find MSYS executables first, which is exactly what you
 274   need.
 275
 276   At this point, you are ready to build Emacs in its basic
 277   configuration.  If you want to build it with image support and other
 278   optional libraries, read about that near the end of this document.
 279
 280 * Generating the configure script
 281
 282   If you are building a release or pretest tarball, skip this section,
 283   because the configure script is already present in the tarball.
 284
 285   To build a development snapshot from the Emacs Bazaar repository,
 286   you will first need to generate the configure script and a few other
 287   auto-generated files.  (If this step, described below, somehow
 288   fails, you can use the files in the autogen/ directory instead, but
 289   they might be outdated, and, most importantly, you are well advised
 290   not to disregard any failures in your local build procedures, as
 291   these are likely to be symptoms of incorrect installation that will
 292   bite you down the road.)
 293
 294   To generate the configure script, type this at the MSYS Bash prompt
 295   from the top-level directory of the Emacs tree:
 296
 297      ./autogen.sh
 298
 299   If successful, this command should produce the following output:
 300
 301      $ ./autogen.sh
 302      Checking whether you have the necessary tools...
 303      (Read INSTALL.BZR for more details on building Emacs)
 304
 305      Checking for autoconf (need at least version 2.65)...
 306      ok
 307      Checking for automake (need at least version 1.11)...
 308      ok
 309      Your system has the required tools, running autoreconf...
 310      You can now run `./configure'.
 311
 312 * Configuring Emacs for MinGW:
 313
 314   Now it's time to run the configure script.  You can do that either
 315   from a separate build directory that is outside of the Emacs source
 316   tree (recommended), or from inside the source tree.  The former is
 317   recommended because it allows you to have several different builds,
 318   e.g., an optimized build and an unoptimized one, of the same
 319   revision of the source tree; the source tree will be left in its
 320   pristine state, without any build products.
 321
 322   You invoke the configure script like this:
 323
 324      /PATH/TO/EMACS/SOURCE/TREE/nt/msysconfig.sh --prefix=PREFIX ...
 325
 326   or, if you are building in-place, i.e. inside the source tree:
 327
 328      ./nt/msysconfig.sh --prefix=PREFIX ...
 329
 330   Here PREFIX is the place where you eventually want to install Emacs
 331   once built, e.g. /d/usr.  We recommend to always use --prefix when
 332   building Emacs on Windows, because the default '/usr/local' is not
 333   appropriate for Windows: it will be mapped by MSYS to something like
 334   C:\MSYS\local, and it will defeat the purpose of PREFIX, which is to
 335   install programs in a single coherent tree resembling Posix systems.
 336   Such a single-tree installation makes sure all the other programs
 337   and packages ported from GNU or Unix systems will work seamlessly
 338   together.  Where exactly is the root of that tree on your system is
 339   something only you, the user who builds Emacs, can know, and the
 340   Emacs build process cannot guess, because usually there's no
 341   '/usr/local' directory on any drive on Windows systems.
 342
 343   Do NOT use Windows-style x:/foo/bar file names on the configure
 344   script command line; use the MSYS-style /x/foo/bar instead.  Using
 345   Windows-style file names was reported to cause subtle and hard to
 346   figure out problems during the build.  This applies both to the
 347   command switches, such as --prefix=, and to the absolute file name
 348   of msysconfig.sh, if you are building outside of the source tree.
 349
 350   You can pass additional options to the configure script, for the
 351   full list type
 352
 353      ./nt/msysconfig.sh --help
 354
 355   As explained in the help text, you may need to tell the script what
 356   are the optional flags to invoke the compiler.  This is needed if
 357   some of your headers and libraries, e.g., those belonging to
 358   optional image libraries, are installed in places where the compiler
 359   normally doesn't look for them.  (Remember that advice above to
 360   avoid such situations? here's is where you will start paying for
 361   disregarding that recommendation.)  For example, if you have libpng
 362   headers in C:\emacs\libs\libpng-1.2.37-lib\include and jpeg library
 363   headers in C:\emacs\libs\jpeg-6b-4-lib\include, you will need to say
 364   something like this:
 365
 366     CPPFLAGS='-I/c/emacs/libs/libpng-1.2.37-lib/include -I/c/emacs/libs/jpeg-6b-4-lib/include' ./nt/msysconfig.sh --prefix=PREFIX
 367
 368   which is quite a mouth-full, especially if you have more directories
 369   to specify...  Perhaps you may wish to revisit your installation
 370   decisions now.
 371
 372   If you have a global site-lisp directory from previous Emacs
 373   installation, and you want Emacs to continue using it, specify it
 374   via the --enable-locallisppath switch to msysconfig.sh, like this:
 375
 376    ./nt/msysconfig.sh --prefix=PREFIX --enable-locallisppath="/d/usr/share/emacs/VERSION/site-lisp:/d/wherever/site-lisp"
 377
 378   Use the normal MSYS /d/foo/bar style to specify directories by their
 379   absolute file names.
 380
 381   A few frequently used options are needed when you want to produce an
 382   unoptimized binary with runtime checks enabled:
 383
 384      CPPFLAGS='-DGLYPH_DEBUG=1' CFLAGS='-O0 -g3' ./nt/msysconfig.sh --prefix=PREFIX --enable-checking
 385
 386   Once invoked, the configure script will run for some time, and, if
 387   successful, will eventually produce a summary of the configuration
 388   like this:
 389
 390      Configured for `i686-pc-mingw32'.
 391
 392        Where should the build process find the source code?    /path/to/emacs/sources
 393        What compiler should emacs be built with?               gcc  -std=gnu99 -O0 -g3
 394        Should Emacs use the GNU version of malloc?             yes
 395        Should Emacs use a relocating allocator for buffers?    yes
 396        Should Emacs use mmap(2) for buffer allocation?         no
 397        What window system should Emacs use?                    w32
 398        What toolkit should Emacs use?                          none
 399        Where do we find X Windows header files?                NONE
 400        Where do we find X Windows libraries?                   NONE
 401        Does Emacs use -lXaw3d?                                 no
 402        Does Emacs use -lXpm?                                   yes
 403        Does Emacs use -ljpeg?                                  yes
 404        Does Emacs use -ltiff?                                  yes
 405        Does Emacs use a gif library?                           yes
 406        Does Emacs use -lpng?                                   yes
 407        Does Emacs use -lrsvg-2?                                no
 408        Does Emacs use imagemagick?                             no
 409        Does Emacs use -lgpm?                                   no
 410        Does Emacs use -ldbus?                                  no
 411        Does Emacs use -lgconf?                                 no
 412        Does Emacs use GSettings?                               no
 413        Does Emacs use -lselinux?                               no
 414        Does Emacs use -lgnutls?                                yes
 415        Does Emacs use -lxml2?                                  yes
 416        Does Emacs use -lfreetype?                              no
 417        Does Emacs use -lm17n-flt?                              no
 418        Does Emacs use -lotf?                                   no
 419        Does Emacs use -lxft?                                   no
 420        Does Emacs use toolkit scroll bars?                     yes
 421
 422   You are almost there, hang on.
 423
 424   If the output is significantly different, or if configure finishes
 425   prematurely and displays some error message, you should examine the
 426   configuration log in config.log and find the reason for the failure.
 427
 428   Once you succeeded in configuring Emacs, and just want to rebuild it
 429   after updating your local repository from the main repository, you
 430   don't need to re-run the configure script manually, unless you want
 431   to change the configure-time options.  Just typing "make" will
 432   re-run configure if necessary with the exact same options you
 433   specified originally, and then go on to invoking Make, described
 434   below.
 435
 436 * Running Make.
 437
 438   This is simple: just type "make" and sit back, watching the fun.
 439
 440   If you  installed a snapshot build  of Make, the build  will be much
 441   faster if  you type "make  -j N" instead, where  N is the  number of
 442   independent processing  units on your  machine.  E.g., on a  core i7
 443   system try using  N of 6 or  even 8.  (If this hangs,  see the notes
 444   above about downgrading to MSYS 1.0.17.)
 445
 446   When Make finishes, you can install the produced binaries:
 447
 448     make install
 449
 450   or, if you want the installed tree to go in a place different from
 451   the configured one, type
 452
 453     make install prefix=WHEREVER
 454
 455   Congrats!  You have built and installed your own Emacs!
 456
 457 * Make targets
 458
 459   The following make targets may be used by users building the source
 460   distribution, or users who have checked out of Bazaar after
 461   an initial bootstrapping.
 462
 463   make
 464   Builds Emacs from the available sources and pre-compiled lisp files.
 465
 466   make install
 467   Installs the built programs and the auxiliary files.
 468
 469   make clean
 470   Removes object and executable files produced by the build process in
 471   the current configuration.  After "make clean", you can rebuild with
 472   the same configuration using make.  useful when you want to be sure
 473   that all of the products are built from coherent sources.
 474
 475   make distclean
 476   In addition to the files removed by make clean, this also removes
 477   Makefiles and other generated files to get back to the state of a
 478   freshly unpacked source distribution.  After make distclean, it is
 479   necessary to run the configure script followed by "make", in order
 480   to rebuild.
 481
 482   The following targets are intended only for use with the Bazaar sources.
 483
 484   make bootstrap
 485   Removes all the auto-generated files and all the *.elc byte-compiled
 486   files, and builds Emacs from scratch.  Useful when some change in
 487   basic Emacs functionality makes byte compilation of updated files
 488   fail.
 489
 490   make maintainer-clean
 491   Removes everything that can be recreated, including compiled Lisp
 492   files, to get back to the state of a fresh Bazaar tree.  After make
 493   maintainer-clean, it is necessary to run configure and "make" or
 494   "make bootstrap" to rebuild.  Occasionally it may be necessary to
 495   run this target after an update.
 496
 497 * Optional image library support
 498
 499   In addition to its "native" image formats (pbm and xbm), Emacs can
 500   handle other image types: xpm, tiff, gif, png, jpeg and experimental
 501   support for svg.
 502
 503   To build Emacs with support for them, the corresponding headers must
 504   be in the include path and libraries should be where the linker
 505   looks for them, when the configure script is run.  If needed, this
 506   can be set up using the CPPFLAGS and CFLAGS variable specified on
 507   the configure command line.  The configure script will report
 508   whether it was able to detect the headers and libraries.  If the
 509   results of this testing appear to be incorrect, please look for
 510   details in the file config.log: it will show the failed test
 511   programs and compiler error messages that should explain what is
 512   wrong.  (Usually, any such failures happen because some headers are
 513   missing due to bad packaging of the image support libraries.)
 514
 515   Note that any file path passed to the compiler or linker must use
 516   forward slashes, or double each backslash, as that is how Bash
 517   works.
 518
 519   If the configure script finds the necessary headers and libraries,
 520   but they are for some reason incompatible, or if you want to omit
 521   support for some image library that is installed on your system for
 522   some other reason, use the --without-PACKAGE option to configure,
 523   such as --without-gif to omit GIF, --without-tiff to omit TIFF, etc.
 524   Passing the --help option to the configure script displays all of
 525   the supported --without-PACKAGE options.
 526
 527   To use the external image support, the DLLs implementing the
 528   functionality must be found when Emacs first needs them, either on the
 529   PATH, or in the same directory as emacs.exe.  Failure to find a
 530   library is not an error; the associated image format will simply be
 531   unavailable.  Note that once Emacs has determined that a library can
 532   not be found, there's no way to force it to try again, other than
 533   restarting.  See the variable `dynamic-library-alist' to configure the
 534   expected names of the libraries.
 535
 536   Some image libraries have dependencies on one another, or on zlib.
 537   For example, tiff support depends on the jpeg library.  If you did not
 538   compile the libraries yourself, you must make sure that any dependency
 539   is in the PATH or otherwise accessible and that the binaries are
 540   compatible (for example, that they were built with the same compiler).
 541
 542   Binaries for the image libraries (among many others) can be found at
 543   the GnuWin32 project.  The PNG libraries are also included with GTK,
 544   which is installed along with other Free Software that requires it.
 545   Note specifically that, due to some packaging snafus in the
 546   GnuWin32-supplied image libraries, you will need to download
 547   _source_ packages for some of the libraries in order to get the
 548   header files necessary for building Emacs with image support.
 549
 550   For PNG images, we recommend to use versions 1.4.x and later of
 551   libpng, because previous versions had security issues.  You can find
 552   precompiled libraries and headers on the GTK download page for
 553   Windows (http://www.gtk.org/download/win32.php).
 554
 555   Versions 1.4.0 and later of libpng are binary incompatible with
 556   earlier versions, so Emacs will only look for libpng libraries which
 557   are compatible with the version it was compiled against.  That
 558   version is given by the value of the Lisp variable `libpng-version';
 559   e.g., 10403 means version 1.4.3.  The variable `dynamic-library-alist'
 560   is automatically set to name only those DLL names that are known to
 561   be compatible with the version given by `libpng-version'.  If PNG
 562   support does not work for you even though you have the support DLL
 563   installed, check the name of the installed DLL against
 564   `dynamic-library-alist' and the value of `libpng-version', and
 565   download compatible DLLs if needed.
 566
 567 * Optional GnuTLS support
 568
 569   To compile with GnuTLS, you will need pkg-config to be installed, as
 570   the configure script invokes pkg-config to find out which compiler
 571   switches to use for GnuTLS.  See above for the URL where you can
 572   find pkg-config for Windows.
 573
 574   You will also need to install the p11-kit package, which is a
 575   dependency of GnuTLS, and its header files are needed for
 576   compilation of programs that use GnuTLS.  You can find p11-kit on
 577   the same site as GnuTLS, see the URL below.
 578
 579   If the configure script finds the GnuTLS header files and libraries
 580   on your system, Emacs is built with GnuTLS support by default; to
 581   avoid that you can pass the argument --without-gnutls.
 582
 583   In order to support GnuTLS at runtime, a GnuTLS-enabled Emacs must
 584   be able to find the relevant DLLs during startup; failure to do so
 585   is not an error, but GnuTLS won't be available to the running
 586   session.
 587
 588   You can get pre-built binaries (including any required DLL and the
 589   header files) at http://sourceforge.net/projects/ezwinports/files/.
 590
 591 * Optional libxml2 support
 592
 593   To compile with libxml2, you will need pkg-config to be installed,
 594   as the configure script invokes pkg-config to find out which
 595   compiler switches to use for libxml2.  See above for the URL where
 596   you can find pkg-config for Windows.
 597
 598   If the configure script finds the libxml2 header files and libraries
 599   on your system, Emacs is built with libxml2 support by default; to
 600   avoid that you can pass the argument --without-libxml2.
 601
 602   In order to support libxml2 at runtime, a libxml2-enabled Emacs must
 603   be able to find the relevant DLLs during startup; failure to do so
 604   is not an error, but libxml2 features won't be available to the
 605   running session.
 606
 607   One place where you can get pre-built Windows binaries of libxml2
 608   (including any required DLL and the header files) is here:
 609
 610      http://sourceforge.net/projects/ezwinports/files/
 611
 612   For runtime support of libxml2, you will also need to install the
 613   libiconv "development" tarball, because the libiconv headers need to
 614   be available to the compiler when you compile with libxml2 support.
 615   A MinGW port of libiconv can be found on the MinGW site:
 616
 617    http://sourceforge.net/projects/mingw/files/MinGW/Base/libiconv/
 618
 619   You need the libiconv-X.Y.Z-N-mingw32-dev.tar.lzma tarball from that
 620   site.
 621
 622 * Experimental SVG support
 623
 624   To compile with SVG, you will need pkg-config to be installed, as
 625   the configure script invokes pkg-config to find out which compiler
 626   switches to use for SVG.  See above for the URL where you can find
 627   pkg-config for Windows.
 628
 629   SVG support is currently experimental, and not built by default.
 630   Specify --with-rsvg and ensure you have all the dependencies in your
 631   include path.  Unless you have built a minimalist librsvg yourself
 632   (untested), librsvg depends on a significant chunk of GTK+ to build,
 633   plus a few Gnome libraries, libxml2, libbz2 and zlib at runtime.  The
 634   easiest way to obtain the dependencies required for building is to
 635   download a pre-bundled GTK+ development environment for Windows.
 636
 637   To use librsvg at runtime, ensure that librsvg and its dependencies
 638   are on your PATH.  If you didn't build librsvg yourself, you will
 639   need to check with where you downloaded it from for the
 640   dependencies, as there are different build options.  If it is a
 641   short list, then it most likely only lists the immediate
 642   dependencies of librsvg, but the dependencies themselves have
 643   dependencies - so don't download individual libraries from GTK+,
 644   download and install the whole thing.  If you think you've got all
 645   the dependencies and SVG support is still not working, check your
 646   PATH for other libraries that shadow the ones you downloaded.
 647   Libraries of the same name from different sources may not be
 648   compatible, this problem was encountered with libbzip2 from GnuWin32
 649   with libcroco from gnome.org.
 650
 651   If you can see etc/images/splash.svg, then you have managed to get
 652   SVG support working.  Congratulations for making it through DLL hell
 653   to this point.  You'll probably find that some SVG images crash
 654   Emacs.  Problems have been observed in some images that contain
 655   text, they seem to be a problem in the Windows port of Pango, or
 656   maybe a problem with the way Cairo or librsvg is using it that
 657   doesn't show up on other platforms.
 658
 659 \f
 660 This file is part of GNU Emacs.
 661
 662 GNU Emacs is free software: you can redistribute it and/or modify
 663 it under the terms of the GNU General Public License as published by
 664 the Free Software Foundation, either version 3 of the License, or
 665 (at your option) any later version.
 666
 667 GNU Emacs is distributed in the hope that it will be useful,
 668 but WITHOUT ANY WARRANTY; without even the implied warranty of
 669 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 670 GNU General Public License for more details.
 671
 672 You should have received a copy of the GNU General Public License
 673 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.