Fix bug #7716 with PNG image support libraries on Windows.
[bpt/emacs.git] / nt / INSTALL
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a4a9692d 1 Building and Installing Emacs
3dfbc6d8 2 on Windows NT/2K/XP and Windows 95/98/ME
a4a9692d 3
114f9c96 4 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
0939da72 5 Free Software Foundation, Inc.
7f6d64f8 6 See the end of the file for license conditions.
4b994b84 7
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8* For the impatient
9
10 Here are the concise instructions for configuring and building the
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11 native Windows binary of Emacs, for those who want to skip the
12 complex explanations and ``just do it'':
0939da72 13
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14 Do not use this recipe with Cygwin. For building on Cygwin,
15 use the normal installation instructions, ../INSTALL.
16
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17 1. Change to the `nt' directory (the directory of this file):
18
19 cd nt
20
21 2. Run configure.bat. From the COMMAND.COM/CMD.EXE command prompt:
22
23 configure
24
25 from a Unixy shell prompt:
26
27 cmd /c configure.bat
28 or
29 command.com /c configure.bat
30
31 3. Run the Make utility suitable for your environment. If you build
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32 with the Microsoft's Visual C compiler (but see notes about using
33 VC++ 8.0 and later below):
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34
35 nmake
36
37 For the development environments based on GNU GCC (MinGW, MSYS,
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38 Cygwin - but see notes about Cygwin make below), depending on how
39 Make is called, it could be:
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40
41 make
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42 or
43 mingw32-make
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44 or
45 gnumake
46 or
47 gmake
48
ee6f37f2 49 (If you are building from Bazaar, say "make bootstrap" or "nmake
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50 bootstrap" instead, and avoid using Cygwin make.)
51
52 With GNU Make, you can use the -j command-line option to have
53 Make execute several commands at once, like this:
54
ecfd8ceb 55 gmake -j 2 XMFLAGS="-j 2"
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56
57 The XMFLAGS variable overrides the default behavior of GNU Make
58 on Windows, whereby recursive Make invocations reset the maximum
59 number of simultaneous commands to 1. The above command allows
60 up to 4 simultaneous commands at once in the top-level Make, and
61 up to 3 in each one of the recursive Make's.
0939da72 62
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63 4. Generate the Info manuals (only if you are building out of Bazaar,
64 and if you have makeinfo.exe installed):
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65
66 make info
67
68 (change "make" to "nmake" if you use MSVC).
69
70 5. Install the produced binaries:
71
72 make install
73
74 That's it!
75
76 If these short instructions somehow fail, read the rest of this
77 file.
78
79* Preliminaries
80
195e32b7 81 If you want to build a Cygwin port of Emacs, use the instructions in
0d801288 82 the INSTALL file in the main Emacs directory (the parent of this
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83 directory). These instructions are for building a native Windows
84 binary of Emacs.
85
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86 If you used WinZip to unpack the distribution, we suggest to
87 remove the files and unpack again with a different program!
88 WinZip is known to create some subtle and hard to debug problems,
177c0ea7 89 such as converting files to DOS CR-LF format, not creating empty
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90 directories, etc. We suggest to use djtarnt.exe from the GNU FTP
91 site.
92
ee6f37f2 93 In addition to this file, you should also read INSTALL.BZR in the
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94 parent directory, and make sure that you have a version of
95 "touch.exe" in your path, and that it will create files that do not
96 yet exist.
589a591b 97
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98* Supported development environments
99
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100 To compile Emacs, you will need either Microsoft Visual C++ 2.0, or
101 later up to 7.0, and nmake, or a Windows port of GCC 2.95 or later
102 with MinGW and W32 API support and a port of GNU Make. You can use
103 the Cygwin ports of GCC, but Emacs requires the MinGW headers and
104 libraries to build (latest versions of the Cygwin toolkit, at least
105 since v1.3.3, include the MinGW headers and libraries as an integral
106 part).
107
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108 Note that building Emacs with Visual Studio 2005 (VC++ 8.0) and
109 later is not supported at this time, due to changes introduced by
110 Microsoft into the libraries shipped with the compiler.
ecfd8ceb 111
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112 The rest of this file assumes you have a working development
113 environment. If you just installed such an environment, try
114 building a trivial C "Hello world" program, and see if it works. If
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115 it doesn't work, resolve that problem first! If you use Microsoft
116 Visual Studio .NET 2003, don't forget to run the VCVARS32.BAT batch
117 file from the `Bin' subdirectory of the directory where you have
118 installed VS.NET.
0939da72 119
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120 If you use the MinGW port of GCC and GNU Make to build Emacs, there
121 are some compatibility issues wrt Make and the shell that is run by
122 Make, either the standard COMMAND.COM/CMD.EXE supplied with Windows
6d96d18f 123 or sh.exe, a port of a Unixy shell. For reference, below is a list
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124 of which builds of GNU Make are known to work or not, and whether
125 they work in the presence and/or absence of sh.exe, the Cygwin port
1640b452 126 of Bash. Note that any version of Make that is compiled with Cygwin
6d96d18f 127 will only work with Cygwin tools, due to the use of Cygwin style
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128 paths. This means Cygwin Make is unsuitable for building parts of
129 Emacs that need to invoke Emacs itself (leim and "make bootstrap",
130 for example). Also see the Trouble-shooting section below if you
131 decide to go ahead and use Cygwin make.
b147d297 132
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133 In addition, using 4NT or TCC as your shell is known to fail the build
134 process, at least since 4NT version 3.01. Use CMD.EXE, the default
135 Windows shell, instead. MSYS sh.exe also appears to cause various
136 problems. If you have MSYS installed, try "make SHELL=cmd.exe" to
137 force the use of cmd.exe instead of sh.exe.
177c0ea7 138
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139 sh exists no sh
140
fc813ef6 141 cygwin b20.1 make (3.75): fails[1, 5] fails[2, 5]
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142 MSVC compiled gmake 3.77: okay okay
143 MSVC compiled gmake 3.78.1: okay okay
144 MSVC compiled gmake 3.79.1: okay okay
bf95665f 145 mingw32/gcc-2.92.2 make (3.77): okay okay[4]
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146 cygwin compiled gmake 3.77: fails[1, 5] fails[2, 5]
147 cygwin compiled make 3.78.1: fails[5] fails[2, 5]
148 cygwin compiled make 3.79.1: fails[3, 5] fails[2?, 5]
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149 cygwin compiled make 3.80: okay[6] fails?[7]
150 cygwin compiled make 3.81: fails fails?[7]
177c0ea7 151 mingw32 compiled make 3.79.1: okay okay
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152 mingw32 compiled make 3.80: okay okay[7]
153 mingw32 compiled make 3.81: okay okay[8]
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154
155 Notes:
156
157 [1] doesn't cope with makefiles with DOS line endings, so must mount
158 emacs source with text!=binary.
159 [2] fails when needs to invoke shell commands; okay invoking gcc etc.
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160 [3] requires LC_MESSAGES support to build; cannot build with early
161 versions of cygwin.
4bcec9a2 162 [4] may fail on Windows 9X and Windows ME; if so, install Bash.
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163 [5] fails when building leim due to the use of cygwin style paths.
164 May work if building emacs without leim.
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165 [6] need to uncomment 3 lines in nt/gmake.defs that invoke `cygpath'
166 (look for "cygpath" near line 85 of gmake.defs).
167 [7] not recommended; please report if you try this combination.
168 [8] tested only on Windows XP.
4bcec9a2 169
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170 Other compilers may work, but specific reports from people that have
171 tried suggest that the Intel C compiler (for example) may produce an
5739d6f8 172 Emacs executable with strange filename completion behavior. Unless
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173 you would like to assist by finding and fixing the cause of any bugs
174 like this, we recommend the use of the supported compilers mentioned
175 in the previous paragraph.
176
177 You will also need a copy of the Posix cp, rm and mv programs. These
178 and other useful Posix utilities can be obtained from one of several
179 projects:
180
0939da72 181 * http://gnuwin32.sourceforge.net/ ( GnuWin32 )
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182 * http://www.mingw.org/ ( MinGW )
183 * http://www.cygwin.com/ ( Cygwin )
184 * http://unxutils.sourceforge.net/ ( UnxUtils )
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185
186 If you build Emacs on Windows 9X or ME, not on Windows 2K/XP or
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187 Windows NT, we suggest to install the Cygwin port of Bash. That is
188 because the native Windows shell COMMAND.COM is too limited; the
189 Emacs build procedure tries very hard to support even such limited
190 shells, but as none of the Windows developers of Emacs work on
191 Windows 9x, we cannot guarantee that it works without a more
192 powerful shell.
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193
194 Additional instructions and help for building Emacs on Windows can be
195 found at the Emacs Wiki:
196
0939da72 197 http://www.emacswiki.org/cgi-bin/wiki/WThirtyTwoInstallationKit
6c72c0c7 198
309c91ff 199 and on these URLs:
6c72c0c7 200
0939da72 201 http://ourcomments.org/Emacs/w32-build-emacs.html
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202 http://derekslager.com/blog/posts/2007/01/emacs-hack-3-compile-emacs-from-cvs-on-windows.ashx
203
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204 Both of those pages were written before Emacs switched from CVS to
205 Bazaar, but the parts about building Emacs still apply in Bazaar.
206 The second URL has instructions for building with MSVC, as well as
207 with MinGW, while the first URL covers only MinGW, but has more
208 details about it.
6c72c0c7 209
6d76a603 210* Configuring
a4a9692d 211
da179dd0 212 Configuration of Emacs is now handled by running configure.bat in the
0939da72 213 `nt' subdirectory. It will detect which compiler you have available,
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214 and generate makefiles accordingly. You can override the compiler
215 detection, and control optimization and debug settings, by specifying
216 options on the command line when invoking configure.
a4a9692d 217
da179dd0 218 To configure Emacs to build with GCC or MSVC, whichever is available,
0939da72 219 simply change to the `nt' subdirectory and run `configure.bat' with no
da179dd0 220 options. To see what options are available, run `configure --help'.
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221 Do NOT use the --no-debug option to configure.bat unless you are
222 absolutely sure the produced binaries will never need to be run under
223 a debugger.
a4a9692d 224
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225 N.B. It is normal to see a few error messages output while configure
226 is running, when gcc support is being tested. These cannot be
5739d6f8 227 suppressed because of limitations in the Windows 9x command.com shell.
17d4e22c 228
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229 You are encouraged to look at the file config.log which shows details
230 for failed tests, after configure.bat finishes. Any unexplained failure
231 should be investigated and perhaps reported as a bug (see the section
232 about reporting bugs in the file README in this directory and in the
233 Emacs manual).
234
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235* Optional image library support
236
3dfbc6d8 237 In addition to its "native" image formats (pbm and xbm), Emacs can
8bc63b1a 238 handle other image types: xpm, tiff, gif, png, jpeg and experimental
707a78b2 239 support for svg.
6d96d18f 240
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241 To build Emacs with support for them, the corresponding headers must
242 be in the include path when the configure script is run. This can
243 be setup using environment variables, or by specifying --cflags
244 -I... options on the command-line to configure.bat. The configure
245 script will report whether it was able to detect the headers. If
246 the results of this testing appear to be incorrect, please look for
247 details in the file config.log: it will show the failed test
248 programs and compiler error messages that should explain what is
249 wrong. (Usually, any such failures happen because some headers are
250 missing due to bad packaging of the image support libraries.)
bfd889ed 251
3dfbc6d8 252 To use the external image support, the DLLs implementing the
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253 functionality must be found when Emacs first needs them, either on the
254 PATH, or in the same directory as emacs.exe. Failure to find a
255 library is not an error; the associated image format will simply be
256 unavailable. Note that once Emacs has determined that a library can
257 not be found, there's no way to force it to try again, other than
258 restarting. See the variable `image-library-alist' to configure the
259 expected names of the libraries.
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260
261 Some image libraries have dependencies on one another, or on zlib.
262 For example, tiff support depends on the jpeg library. If you did not
263 compile the libraries yourself, you must make sure that any dependency
5739d6f8 264 is in the PATH or otherwise accessible and that the binaries are
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265 compatible (for example, that they were built with the same compiler).
266
267 Binaries for the image libraries (among many others) can be found at
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268 the GnuWin32 project. PNG, JPEG and TIFF libraries are also
269 included with GTK, which is installed along with other Free Software
270 that requires it. These are built with MinGW, but they can be used
271 with both GCC/MinGW and MSVC builds of Emacs. See the info on
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272 http://ourcomments.org/Emacs/w32-build-emacs.html, under "How to Get
273 Images Support", for more details about installing image support
274 libraries. Note specifically that, due to some packaging snafus in
275 the GnuWin32-supplied image libraries, you will need to download
276 _source_ packages for some of the libraries in order to get the
277 header files necessary for building Emacs with image support.
bfd889ed 278
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279 If GTK 2.0 is installed, addpm will arrange for its image libraries
280 to be on the DLL search path for Emacs.
281
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282 For PNG images, we recommend to use versions 1.4.x and later of
283 libpng, because previous versions had security issues. You can find
284 precompiled libraries and headers on the GTK download page for
285 Windows (http://www.gtk.org/download-windows.html).
286
287 Versions 1.4.0 and later of libpng are binary incompatible with
288 earlier versions, so Emacs will only look for libpng libraries which
289 are compatible with the version it was compiled against. That
290 version is given by the value of the Lisp variable `libpng-version';
291 e.g., 10403 means version 1.4.3. The variable `image-library-alist'
292 is automatically set to name only those DLL names that are known to
293 be compatible with the version given by `libpng-version'. If PNG
294 support does not work for you even though you have the support DLL
295 installed, check the name of the installed DLL against
296 `image-library-alist' and the value of `libpng-version', and
297 download compatible DLLs if needed.
298
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299* Experimental SVG support
300
301 SVG support is currently experimental, and not built by default.
302 Specify --with-svg and ensure you have all the dependencies in your
1640b452 303 include path. Unless you have built a minimalist librsvg yourself
8bc63b1a 304 (untested), librsvg depends on a significant chunk of GTK+ to build,
1640b452 305 plus a few Gnome libraries, libxml2, libbz2 and zlib at runtime. The
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306 easiest way to obtain the dependencies required for building is to
307 download a pre-bundled GTK+ development environment for Windows.
308 GTK puts its header files all over the place, so you will need to
309 run pkgconfig to list the include path you will need (either passed
310 to configure.bat as --cflags options, or set in the environment).
311
312 To use librsvg at runtime, ensure that librsvg and its dependencies
313 are on your PATH. If you didn't build librsvg yourself, you will
314 need to check with where you downloaded it from for the
315 dependencies, as there are different build options. If it is a
316 short list, then it most likely only lists the immediate
317 dependencies of librsvg, but the dependencies themselves have
318 dependencies - so don't download individual libraries from GTK+,
1640b452 319 download and install the whole thing. If you think you've got all
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320 the dependencies and SVG support is still not working, check your
321 PATH for other libraries that shadow the ones you downloaded.
322 Libraries of the same name from different sources may not be
323 compatible, this problem was encountered with libbzip2 from GnuWin32
324 with libcroco from gnome.org.
325
326 If you can see etc/images/splash.svg, then you have managed to get
327 SVG support working. Congratulations for making it through DLL hell
1640b452 328 to this point. You'll probably find that some SVG images crash
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329 Emacs. Problems have been observed in some images that contain
330 text, they seem to be a problem in the Windows port of Pango, or
331 maybe a problem with the way Cairo or librsvg is using it that
332 doesn't show up on other platforms.
333
6d76a603 334* Building
a4a9692d 335
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336 After running configure, simply run the appropriate `make' program for
337 your compiler to build Emacs. For MSVC, this is nmake; for GCC, it is
ee6f37f2 338 GNU make. (If you are building out of Bazaar, say "make bootstrap" or
0939da72 339 "nmake bootstrap" instead.)
a4a9692d 340
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341 As the files are compiled, you will see some warning messages
342 declaring that some functions don't return a value, or that some data
343 conversions will be lossy, etc. You can safely ignore these messages.
344 The warnings may be fixed in the main FSF source at some point, but
345 until then we will just live with them.
a4a9692d 346
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347 With GNU Make, you can use the -j command-line option to have Make
348 execute several commands at once, like this:
349
350 gmake -j 4 XMFLAGS="-j 3"
351
352 The XMFLAGS variable overrides the default behavior of GNU Make on
353 Windows, whereby recursive Make invocations reset the maximum number
354 of simultaneous commands to 1. The above command allows up to 4
355 simultaneous commands at once in the top-level Make, and up to 3 in
356 each one of the recursive Make's; you can use other numbers of jobs,
357 if you wish.
358
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359 If you are building from Bazaar, the following commands will produce
360 the Info manuals (which are not part of the Bazaar sources):
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361
362 make info
363 or
364 nmake info
365
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366 Note that you will need makeinfo.exe (from the GNU Texinfo package)
367 in order for this command to succeed.
368
6d76a603 369* Installing
a4a9692d 370
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371 To install Emacs after it has compiled, simply run `nmake install'
372 or `make install', depending on which version of the Make utility
373 do you have.
a4a9692d 374
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375 By default, Emacs will be installed in the location where it was
376 built, but a different location can be specified either using the
377 --prefix option to configure, or by setting INSTALL_DIR when running
378 make, like so:
a4a9692d 379
da179dd0 380 make install INSTALL_DIR=D:/emacs
a4a9692d 381
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382 (for `nmake', type "nmake install INSTALL_DIR=D:/emacs" instead).
383
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384 The install process will run addpm to setup the registry entries, and
385 to create a Start menu icon for Emacs.
a4a9692d 386
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387* Make targets
388
389 The following make targets may be used by users building the source
ee6f37f2 390 distribution, or users who have checked out of Bazaar after
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391 an initial bootstrapping.
392
393 make
394 Builds Emacs from the available sources and pre-compiled lisp files.
395
396 make install
397 Installs programs to the bin directory, and runs addpm to create
398 Start Menu icons.
399
400 make clean
401 Removes object and executable files produced by the build process in
402 the current configuration. After make clean, you can rebuild with
403 the same configuration using make.
404
405 make distclean
406 In addition to the files removed by make clean, this also removes
407 Makefiles and other generated files to get back to the state of a
1640b452 408 freshly unpacked source distribution. Note that this will not remove
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409 installed files, or the results of builds performed with different
410 compiler or optimization options than the current configuration.
411 After make distclean, it is necessary to run configure.bat followed
412 by make to rebuild.
413
414 make cleanall
415 Removes object and executable files that may have been created by
416 previous builds with different configure options, in addition to
417 the files produced by the current configuration.
418
419 make realclean
420 Removes the installed files in the bin subdirectory in addition to
421 the files removed by make cleanall.
422
423
ee6f37f2 424 The following targets are intended only for use with the Bazaar sources.
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425
426 make bootstrap
427 Creates a temporary emacs binary with lisp source files and
428 uses it to compile the lisp files. Once the lisp files are built,
429 emacs is redumped with the compiled lisp.
430
431 make recompile
ee6f37f2 432 Recompiles any changed lisp files after an update. This saves
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433 doing a full bootstrap after every update. If this or a subsequent
434 make fail, you probably need to perform a full bootstrap, though
435 running this target multiple times may eventually sort out the
436 interdependencies.
437
438 make maintainer-clean
439 Removes everything that can be recreated, including compiled lisp
ee6f37f2 440 files, to get back to the state of a fresh Bazaar tree. After make
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441 maintainer-clean, it is necessary to run configure.bat and make
442 bootstrap to rebuild. Occasionally it may be necessary to run this
ee6f37f2 443 target after an update.
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444
445
6d76a603 446* Trouble-shooting
a4a9692d 447
da179dd0 448 The main problems that are likely to be encountered when building
bd7bdff8 449 Emacs stem from using an old version of GCC, or old MinGW or W32 API
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450 headers. Additionally, cygwin ports of GNU make may require the Emacs
451 source tree to be mounted with text!=binary, because the makefiles
452 generated by configure.bat necessarily use DOS line endings. Also,
453 cygwin ports of make must run in UNIX mode, either by specifying
454 --unix on the command line, or MAKE_MODE=UNIX in the environment.
a4a9692d 455
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456 When configure runs, it attempts to detect when GCC itself, or the
457 headers it is using, are not suitable for building Emacs. GCC version
458 2.95 or later is needed, because that is when the Windows port gained
459 sufficient support for anonymous structs and unions to cope with some
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460 definitions from winnt.h that are used by addsection.c.
461 Older versions of the W32 API headers that come with Cygwin and MinGW
462 may be missing some definitions required by Emacs, or broken in other
4a00b4b3 463 ways. In particular, uniscribe APIs were added to MinGW CVS only on
a25fe288 464 2006-03-26, so releases from before then cannot be used.
a4a9692d 465
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466 When in doubt about correctness of what configure did, look at the file
467 config.log, which shows all the failed test programs and compiler
468 messages associated with the failures. If that doesn't give a clue,
469 please report the problems, together with the relevant fragments from
470 config.log, as bugs.
471
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472 If configure succeeds, but make fails, install the Cygwin port of
473 Bash, even if the table above indicates that Emacs should be able to
474 build without sh.exe. (Some versions of Windows shells are too dumb
475 for Makefile's used by Emacs.)
476
8481e41e 477 If you are using certain Cygwin builds of GCC, such as Cygwin version
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478 1.1.8, you may need to specify some extra compiler flags like so:
479
480 configure --with-gcc --cflags -mwin32 --cflags -D__MSVCRT__
315746cc 481 --ldflags -mwin32
6d76a603 482
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483 However, the latest Cygwin versions, such as 1.3.3, don't need those
484 switches; you can simply use "configure --with-gcc".
485
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486 We will attempt to auto-detect the need for these flags in a future
487 release.
488
489* Debugging
a4a9692d 490
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491 You should be able to debug Emacs using the debugger that is
492 appropriate for the compiler you used, namely DevStudio or Windbg if
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493 compiled with MSVC, or GDB if compiled with GCC. (GDB for Windows
494 is available from the MinGW site, http://www.mingw.org/download.shtml.)
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495
496 When Emacs aborts due to a fatal internal error, Emacs on Windows
497 pops up an Emacs Abort Dialog asking you whether you want to debug
498 Emacs or terminate it. If Emacs was built with MSVC, click YES
499 twice, and Windbg or the DevStudio debugger will start up
500 automatically. If Emacs was built with GCC, first start GDB and
501 attach it to the Emacs process with the "gdb -p EMACS-PID" command,
502 where EMACS-PID is the Emacs process ID (which you can see in the
503 Windows Task Manager), type the "continue" command inside GDB, and
504 only then click YES on the abort dialog. This will pass control to
505 the debugger, and you will be able to debug the cause of the fatal
506 error.
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507
508 Emacs functions implemented in C use a naming convention that reflects
509 their names in lisp. The names of the C routines are the lisp names
510 prefixed with 'F', and with dashes converted to underscores. For
511 example, the function call-process is implemented in C by
512 Fcall_process. Similarly, lisp variables are prefixed with 'V', again
513 with dashes converted to underscores. These conventions enable you to
514 easily set breakpoints or examine familiar lisp variables by name.
515
516 Since Emacs data is often in the form of a lisp object, and the
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517 Lisp_Object type is difficult to examine manually in a debugger,
518 Emacs provides a helper routine called debug_print that prints out a
519 readable representation of a Lisp_Object. If you are using GDB,
520 there is a .gdbinit file in the src directory which provides
521 definitions that are useful for examining lisp objects. Therefore,
522 the following tips are mainly of interest when using MSVC.
523
524 The output from debug_print is sent to stderr, and to the debugger
525 via the OutputDebugString routine. The output sent to stderr should
526 be displayed in the console window that was opened when the
527 emacs.exe executable was started. The output sent to the debugger
528 should be displayed in its "Debug" output window.
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529
530 When you are in the process of debugging Emacs and you would like to
5739d6f8 531 examine the contents of a Lisp_Object variable, pop up the QuickWatch
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532 window (QuickWatch has an eyeglass symbol on its button in the
533 toolbar). In the text field at the top of the window, enter
534 debug_print(<variable>) and hit return. For example, start and run
535 Emacs in the debugger until it is waiting for user input. Then click
536 on the Break button in the debugger to halt execution. Emacs should
537 halt in ZwUserGetMessage waiting for an input event. Use the Call
538 Stack window to select the procedure w32_msp_pump up the call stack
539 (see below for why you have to do this). Open the QuickWatch window
540 and enter debug_print(Vexec_path). Evaluating this expression will
541 then print out the contents of the lisp variable exec-path.
542
543 If QuickWatch reports that the symbol is unknown, then check the call
544 stack in the Call Stack window. If the selected frame in the call
545 stack is not an Emacs procedure, then the debugger won't recognize
546 Emacs symbols. Instead, select a frame that is inside an Emacs
547 procedure and try using debug_print again.
548
549 If QuickWatch invokes debug_print but nothing happens, then check the
550 thread that is selected in the debugger. If the selected thread is
551 not the last thread to run (the "current" thread), then it cannot be
552 used to execute debug_print. Use the Debug menu to select the current
553 thread and try using debug_print again. Note that the debugger halts
554 execution (e.g., due to a breakpoint) in the context of the current
555 thread, so this should only be a problem if you've explicitly switched
556 threads.
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558\f
559This file is part of GNU Emacs.
4b994b84 560
eef0be9e 561GNU Emacs is free software: you can redistribute it and/or modify
7f6d64f8 562it under the terms of the GNU General Public License as published by
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563the Free Software Foundation, either version 3 of the License, or
564(at your option) any later version.
4b994b84 565
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566GNU Emacs is distributed in the hope that it will be useful,
567but WITHOUT ANY WARRANTY; without even the implied warranty of
568MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
569GNU General Public License for more details.
570
571You should have received a copy of the GNU General Public License
eef0be9e 572along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.