Modified the code that parses the --cflags and --ldflags options to support parameter...
[bpt/emacs.git] / nt / INSTALL
1 Building and Installing Emacs on Windows
2 (from 95 to 7 and beyond)
3
4 Copyright (C) 2001-2011 Free Software Foundation, Inc.
5 See the end of the file for license conditions.
6
7 * For the impatient
8
9 Here are the concise instructions for configuring and building the
10 native Windows binary of Emacs, for those who want to skip the
11 complex explanations and ``just do it'':
12
13 Do not use this recipe with Cygwin. For building on Cygwin,
14 use the normal installation instructions, ../INSTALL.
15
16 1. Change to the `nt' directory (the directory of this file):
17
18 cd nt
19
20 2. Run configure.bat. From the COMMAND.COM/CMD.EXE command prompt:
21
22 configure
23
24 from a Unixy shell prompt:
25
26 cmd /c configure.bat
27 or
28 command.com /c configure.bat
29
30 3. Run the Make utility suitable for your environment. If you build
31 with the Microsoft's Visual C compiler (but see notes about using
32 VC++ 8.0 and later below):
33
34 nmake
35
36 For the development environments based on GNU GCC (MinGW, MSYS,
37 Cygwin - but see notes about Cygwin make below), depending on how
38 Make is called, it could be:
39
40 make
41 or
42 mingw32-make
43 or
44 gnumake
45 or
46 gmake
47
48 (If you are building from Bazaar, say "make bootstrap" or "nmake
49 bootstrap" instead, and avoid using Cygwin make.)
50
51 With GNU Make, you can use the -j command-line option to have
52 Make execute several commands at once, like this:
53
54 gmake -j 2 XMFLAGS="-j 2"
55
56 The XMFLAGS variable overrides the default behavior of GNU Make
57 on Windows, whereby recursive Make invocations reset the maximum
58 number of simultaneous commands to 1. The above command allows
59 up to 4 simultaneous commands at once in the top-level Make, and
60 up to 3 in each one of the recursive Make's.
61
62 4. Generate the Info manuals (only if you are building out of Bazaar,
63 and if you have makeinfo.exe installed):
64
65 make info
66
67 (change "make" to "nmake" if you use MSVC).
68
69 5. Install the produced binaries:
70
71 make install
72
73 That's it!
74
75 If these short instructions somehow fail, read the rest of this
76 file.
77
78 * Preliminaries
79
80 If you want to build a Cygwin port of Emacs, use the instructions in
81 the INSTALL file in the main Emacs directory (the parent of this
82 directory). These instructions are for building a native Windows
83 binary of Emacs.
84
85 If you used WinZip to unpack the distribution, we suggest to
86 remove the files and unpack again with a different program!
87 WinZip is known to create some subtle and hard to debug problems,
88 such as converting files to DOS CR-LF format, not creating empty
89 directories, etc. We suggest to use djtarnt.exe from the GNU FTP
90 site.
91
92 In addition to this file, you should also read INSTALL.BZR in the
93 parent directory, and make sure that you have a version of
94 "touch.exe" in your path, and that it will create files that do not
95 yet exist.
96
97 * Supported development environments
98
99 To compile Emacs, you will need either Microsoft Visual C++ 2.0, or
100 later up to 7.0, and nmake, or a Windows port of GCC 2.95 or later
101 with MinGW and W32 API support and a port of GNU Make. You can use
102 the Cygwin ports of GCC, but Emacs requires the MinGW headers and
103 libraries to build (latest versions of the Cygwin toolkit, at least
104 since v1.3.3, include the MinGW headers and libraries as an integral
105 part).
106
107 Note that building Emacs with Visual Studio 2005 (VC++ 8.0) and
108 later is not supported at this time, due to changes introduced by
109 Microsoft into the libraries shipped with the compiler.
110
111 The rest of this file assumes you have a working development
112 environment. If you just installed such an environment, try
113 building a trivial C "Hello world" program, and see if it works. If
114 it doesn't work, resolve that problem first! If you use Microsoft
115 Visual Studio .NET 2003, don't forget to run the VCVARS32.BAT batch
116 file from the `Bin' subdirectory of the directory where you have
117 installed VS.NET.
118
119 If you use the MinGW port of GCC and GNU Make to build Emacs, there
120 are some compatibility issues wrt Make and the shell that is run by
121 Make, either the standard COMMAND.COM/CMD.EXE supplied with Windows
122 or sh.exe, a port of a Unixy shell. For reference, below is a list
123 of which builds of GNU Make are known to work or not, and whether
124 they work in the presence and/or absence of sh.exe, the Cygwin port
125 of Bash. Note that any version of Make that is compiled with Cygwin
126 will only work with Cygwin tools, due to the use of Cygwin style
127 paths. This means Cygwin Make is unsuitable for building parts of
128 Emacs that need to invoke Emacs itself (leim and "make bootstrap",
129 for example). Also see the Trouble-shooting section below if you
130 decide to go ahead and use Cygwin make.
131
132 In addition, using 4NT or TCC as your shell is known to fail the build
133 process, at least since 4NT version 3.01. Use CMD.EXE, the default
134 Windows shell, instead. MSYS sh.exe also appears to cause various
135 problems. If you have MSYS installed, try "make SHELL=cmd.exe" to
136 force the use of cmd.exe instead of sh.exe.
137
138 sh exists no sh
139
140 cygwin b20.1 make (3.75): fails[1, 5] fails[2, 5]
141 MSVC compiled gmake 3.77: okay okay
142 MSVC compiled gmake 3.78.1: okay okay
143 MSVC compiled gmake 3.79.1: okay okay
144 mingw32/gcc-2.92.2 make (3.77): okay okay[4]
145 cygwin compiled gmake 3.77: fails[1, 5] fails[2, 5]
146 cygwin compiled make 3.78.1: fails[5] fails[2, 5]
147 cygwin compiled make 3.79.1: fails[3, 5] fails[2?, 5]
148 cygwin compiled make 3.80: okay[6] fails?[7]
149 cygwin compiled make 3.81: fails fails?[7]
150 mingw32 compiled make 3.79.1: okay okay
151 mingw32 compiled make 3.80: okay okay[7]
152 mingw32 compiled make 3.81: okay okay[8]
153
154 Notes:
155
156 [1] doesn't cope with makefiles with DOS line endings, so must mount
157 emacs source with text!=binary.
158 [2] fails when needs to invoke shell commands; okay invoking gcc etc.
159 [3] requires LC_MESSAGES support to build; cannot build with early
160 versions of Cygwin.
161 [4] may fail on Windows 9X and Windows ME; if so, install Bash.
162 [5] fails when building leim due to the use of cygwin style paths.
163 May work if building emacs without leim.
164 [6] need to uncomment 3 lines in nt/gmake.defs that invoke `cygpath'
165 (look for "cygpath" near line 85 of gmake.defs).
166 [7] not recommended; please report if you try this combination.
167 [8] tested only on Windows XP.
168
169 Other compilers may work, but specific reports from people that have
170 tried suggest that the Intel C compiler (for example) may produce an
171 Emacs executable with strange filename completion behavior. Unless
172 you would like to assist by finding and fixing the cause of any bugs
173 like this, we recommend the use of the supported compilers mentioned
174 in the previous paragraph.
175
176 You will also need a copy of the POSIX cp, rm and mv programs. These
177 and other useful POSIX utilities can be obtained from one of several
178 projects:
179
180 * http://gnuwin32.sourceforge.net/ ( GnuWin32 )
181 * http://www.mingw.org/ ( MinGW )
182 * http://www.cygwin.com/ ( Cygwin )
183 * http://unxutils.sourceforge.net/ ( UnxUtils )
184
185 If you build Emacs on 16-bit versions of Windows (9X or ME), we
186 suggest to install the Cygwin port of Bash. That is because the
187 native Windows shell COMMAND.COM is too limited; the Emacs build
188 procedure tries very hard to support even such limited shells, but
189 as none of the Windows developers of Emacs work on Windows 9X, we
190 cannot guarantee that it works without a more powerful shell.
191
192 Additional instructions and help for building Emacs on Windows can be
193 found at the Emacs Wiki:
194
195 http://www.emacswiki.org/cgi-bin/wiki/WThirtyTwoInstallationKit
196
197 and on these URLs:
198
199 http://ourcomments.org/Emacs/w32-build-emacs.html
200 http://derekslager.com/blog/posts/2007/01/emacs-hack-3-compile-emacs-from-cvs-on-windows.ashx
201
202 Both of those pages were written before Emacs switched from CVS to
203 Bazaar, but the parts about building Emacs still apply in Bazaar.
204 The second URL has instructions for building with MSVC, as well as
205 with MinGW, while the first URL covers only MinGW, but has more
206 details about it.
207
208 * Configuring
209
210 Configuration of Emacs is now handled by running configure.bat in the
211 `nt' subdirectory. It will detect which compiler you have available,
212 and generate makefiles accordingly. You can override the compiler
213 detection, and control optimization and debug settings, by specifying
214 options on the command line when invoking configure.
215
216 To configure Emacs to build with GCC or MSVC, whichever is available,
217 simply change to the `nt' subdirectory and run `configure.bat' with no
218 options. To see what options are available, run `configure --help'.
219 Do NOT use the --no-debug option to configure.bat unless you are
220 absolutely sure the produced binaries will never need to be run under
221 a debugger.
222
223 Because of limitations of the stock Windows command shells, special
224 care is needed to pass some characters in the arguments of the
225 --cflags and --ldflags options. Backslashes should not be used in
226 file names passed to the compiler and linker via these options. Use
227 forward slashes instead. If the arguments to these two options
228 include the `=' character, like when passing a -DFOO=bar preprocessor
229 option, the argument with the `=' character should be enclosed in
230 quotes, like this:
231
232 configure --cflags "-DFOO=bar"
233
234 Support for options that include the `=' character require "command
235 extensions" to be enabled. (They are enabled by default, but your
236 system administrator could have changed that. See "cmd /?" for
237 details.) If command extensions are disabled, a warning message might
238 be displayed informing you that "using parameters that include the =
239 character by enclosing them in quotes will not be supported."
240
241 N.B. It is normal to see a few error messages output while configure
242 is running, when gcc support is being tested. These cannot be
243 suppressed because of limitations in the Windows 9X command.com shell.
244
245 You are encouraged to look at the file config.log which shows details
246 for failed tests, after configure.bat finishes. Any unexplained failure
247 should be investigated and perhaps reported as a bug (see the section
248 about reporting bugs in the file README in this directory and in the
249 Emacs manual).
250
251 * Optional image library support
252
253 In addition to its "native" image formats (pbm and xbm), Emacs can
254 handle other image types: xpm, tiff, gif, png, jpeg and experimental
255 support for svg.
256
257 To build Emacs with support for them, the corresponding headers must
258 be in the include path when the configure script is run. This can
259 be setup using environment variables, or by specifying --cflags
260 -I... options on the command-line to configure.bat. The configure
261 script will report whether it was able to detect the headers. If
262 the results of this testing appear to be incorrect, please look for
263 details in the file config.log: it will show the failed test
264 programs and compiler error messages that should explain what is
265 wrong. (Usually, any such failures happen because some headers are
266 missing due to bad packaging of the image support libraries.)
267
268 Note that any file path passed to the compiler or linker must use
269 forward slashes; using backslashes will cause compiler warnings or
270 errors about unrecognized escape sequences.
271
272 To use the external image support, the DLLs implementing the
273 functionality must be found when Emacs first needs them, either on the
274 PATH, or in the same directory as emacs.exe. Failure to find a
275 library is not an error; the associated image format will simply be
276 unavailable. Note that once Emacs has determined that a library can
277 not be found, there's no way to force it to try again, other than
278 restarting. See the variable `dynamic-library-alist' to configure the
279 expected names of the libraries.
280
281 Some image libraries have dependencies on one another, or on zlib.
282 For example, tiff support depends on the jpeg library. If you did not
283 compile the libraries yourself, you must make sure that any dependency
284 is in the PATH or otherwise accessible and that the binaries are
285 compatible (for example, that they were built with the same compiler).
286
287 Binaries for the image libraries (among many others) can be found at
288 the GnuWin32 project. PNG, JPEG and TIFF libraries are also
289 included with GTK, which is installed along with other Free Software
290 that requires it. These are built with MinGW, but they can be used
291 with both GCC/MinGW and MSVC builds of Emacs. See the info on
292 http://ourcomments.org/Emacs/w32-build-emacs.html, under "How to Get
293 Images Support", for more details about installing image support
294 libraries. Note specifically that, due to some packaging snafus in
295 the GnuWin32-supplied image libraries, you will need to download
296 _source_ packages for some of the libraries in order to get the
297 header files necessary for building Emacs with image support.
298
299 If GTK 2.0 is installed, addpm will arrange for its image libraries
300 to be on the DLL search path for Emacs.
301
302 For PNG images, we recommend to use versions 1.4.x and later of
303 libpng, because previous versions had security issues. You can find
304 precompiled libraries and headers on the GTK download page for
305 Windows (http://www.gtk.org/download-windows.html).
306
307 Versions 1.4.0 and later of libpng are binary incompatible with
308 earlier versions, so Emacs will only look for libpng libraries which
309 are compatible with the version it was compiled against. That
310 version is given by the value of the Lisp variable `libpng-version';
311 e.g., 10403 means version 1.4.3. The variable `dynamic-library-alist'
312 is automatically set to name only those DLL names that are known to
313 be compatible with the version given by `libpng-version'. If PNG
314 support does not work for you even though you have the support DLL
315 installed, check the name of the installed DLL against
316 `dynamic-library-alist' and the value of `libpng-version', and
317 download compatible DLLs if needed.
318
319 * Experimental SVG support
320
321 SVG support is currently experimental, and not built by default.
322 Specify --with-svg and ensure you have all the dependencies in your
323 include path. Unless you have built a minimalist librsvg yourself
324 (untested), librsvg depends on a significant chunk of GTK+ to build,
325 plus a few Gnome libraries, libxml2, libbz2 and zlib at runtime. The
326 easiest way to obtain the dependencies required for building is to
327 download a pre-bundled GTK+ development environment for Windows.
328 GTK puts its header files all over the place, so you will need to
329 run pkgconfig to list the include path you will need (either passed
330 to configure.bat as --cflags options, or set in the environment).
331
332 To use librsvg at runtime, ensure that librsvg and its dependencies
333 are on your PATH. If you didn't build librsvg yourself, you will
334 need to check with where you downloaded it from for the
335 dependencies, as there are different build options. If it is a
336 short list, then it most likely only lists the immediate
337 dependencies of librsvg, but the dependencies themselves have
338 dependencies - so don't download individual libraries from GTK+,
339 download and install the whole thing. If you think you've got all
340 the dependencies and SVG support is still not working, check your
341 PATH for other libraries that shadow the ones you downloaded.
342 Libraries of the same name from different sources may not be
343 compatible, this problem was encountered with libbzip2 from GnuWin32
344 with libcroco from gnome.org.
345
346 If you can see etc/images/splash.svg, then you have managed to get
347 SVG support working. Congratulations for making it through DLL hell
348 to this point. You'll probably find that some SVG images crash
349 Emacs. Problems have been observed in some images that contain
350 text, they seem to be a problem in the Windows port of Pango, or
351 maybe a problem with the way Cairo or librsvg is using it that
352 doesn't show up on other platforms.
353
354 * Building
355
356 After running configure, simply run the appropriate `make' program for
357 your compiler to build Emacs. For MSVC, this is nmake; for GCC, it is
358 GNU make. (If you are building out of Bazaar, say "make bootstrap" or
359 "nmake bootstrap" instead.)
360
361 As the files are compiled, you will see some warning messages
362 declaring that some functions don't return a value, or that some data
363 conversions will be lossy, etc. You can safely ignore these messages.
364 The warnings may be fixed in the main FSF source at some point, but
365 until then we will just live with them.
366
367 With GNU Make, you can use the -j command-line option to have Make
368 execute several commands at once, like this:
369
370 gmake -j 4 XMFLAGS="-j 3"
371
372 The XMFLAGS variable overrides the default behavior of GNU Make on
373 Windows, whereby recursive Make invocations reset the maximum number
374 of simultaneous commands to 1. The above command allows up to 4
375 simultaneous commands at once in the top-level Make, and up to 3 in
376 each one of the recursive Make's; you can use other numbers of jobs,
377 if you wish.
378
379 If you are building from Bazaar, the following commands will produce
380 the Info manuals (which are not part of the Bazaar sources):
381
382 make info
383 or
384 nmake info
385
386 Note that you will need makeinfo.exe (from the GNU Texinfo package)
387 in order for this command to succeed.
388
389 * Installing
390
391 To install Emacs after it has compiled, simply run `nmake install'
392 or `make install', depending on which version of the Make utility
393 do you have.
394
395 By default, Emacs will be installed in the location where it was
396 built, but a different location can be specified either using the
397 --prefix option to configure, or by setting INSTALL_DIR when running
398 make, like so:
399
400 make install INSTALL_DIR=D:/emacs
401
402 (for `nmake', type "nmake install INSTALL_DIR=D:/emacs" instead).
403
404 The install process will run addpm to setup the registry entries, and
405 to create a Start menu icon for Emacs.
406
407 * Make targets
408
409 The following make targets may be used by users building the source
410 distribution, or users who have checked out of Bazaar after
411 an initial bootstrapping.
412
413 make
414 Builds Emacs from the available sources and pre-compiled lisp files.
415
416 make install
417 Installs programs to the bin directory, and runs addpm to create
418 Start Menu icons.
419
420 make clean
421 Removes object and executable files produced by the build process in
422 the current configuration. After make clean, you can rebuild with
423 the same configuration using make.
424
425 make distclean
426 In addition to the files removed by make clean, this also removes
427 Makefiles and other generated files to get back to the state of a
428 freshly unpacked source distribution. Note that this will not remove
429 installed files, or the results of builds performed with different
430 compiler or optimization options than the current configuration.
431 After make distclean, it is necessary to run configure.bat followed
432 by make to rebuild.
433
434 make cleanall
435 Removes object and executable files that may have been created by
436 previous builds with different configure options, in addition to
437 the files produced by the current configuration.
438
439 make realclean
440 Removes the installed files in the bin subdirectory in addition to
441 the files removed by make cleanall.
442
443 make dist
444 Builds Emacs from the available sources and pre-compiled lisp files.
445 Packages Emacs binaries as full distribution and barebin distribution.
446
447 The following targets are intended only for use with the Bazaar sources.
448
449 make bootstrap
450 Creates a temporary emacs binary with lisp source files and
451 uses it to compile the lisp files. Once the lisp files are built,
452 emacs is redumped with the compiled lisp.
453
454 make recompile
455 Recompiles any changed lisp files after an update. This saves
456 doing a full bootstrap after every update. If this or a subsequent
457 make fail, you probably need to perform a full bootstrap, though
458 running this target multiple times may eventually sort out the
459 interdependencies.
460
461 make maintainer-clean
462 Removes everything that can be recreated, including compiled lisp
463 files, to get back to the state of a fresh Bazaar tree. After make
464 maintainer-clean, it is necessary to run configure.bat and make
465 bootstrap to rebuild. Occasionally it may be necessary to run this
466 target after an update.
467
468 * Creating binary distributions
469
470 Binary distributions (full and barebin distributions) can be
471 automatically built and packaged from source tarballs or a bzr
472 checkout.
473
474 When building Emacs binary distributions, the --distfiles argument
475 to configure.bat specifies files to be included in the bin directory
476 of the binary distributions. This is intended for libraries that are
477 not built as part of Emacs, e.g. image libraries.
478
479 For example, specifying
480
481 --distfiles D:\distfiles\libXpm.dll
482
483 results in libXpm.dll being copied from D:\distfiles to the
484 bin directory before packaging starts.
485
486 Multiple files can be specified using multiple --distfiles arguments:
487
488 --distfiles D:\distfiles\libXpm.dll --distfiles C:\jpeglib\jpeg.dll
489
490 For packaging the binary distributions, the 'dist' make target uses
491 7-Zip (http://www.7-zip.org), which must be installed and available
492 on the Windows Path.
493
494
495 * Trouble-shooting
496
497 The main problems that are likely to be encountered when building
498 Emacs stem from using an old version of GCC, or old MinGW or W32 API
499 headers. Additionally, Cygwin ports of GNU make may require the Emacs
500 source tree to be mounted with text!=binary, because the makefiles
501 generated by configure.bat necessarily use DOS line endings. Also,
502 Cygwin ports of make must run in UNIX mode, either by specifying
503 --unix on the command line, or MAKE_MODE=UNIX in the environment.
504
505 When configure runs, it attempts to detect when GCC itself, or the
506 headers it is using, are not suitable for building Emacs. GCC version
507 2.95 or later is needed, because that is when the Windows port gained
508 sufficient support for anonymous structs and unions to cope with some
509 definitions from winnt.h that are used by addsection.c.
510 Older versions of the W32 API headers that come with Cygwin and MinGW
511 may be missing some definitions required by Emacs, or broken in other
512 ways. In particular, uniscribe APIs were added to MinGW CVS only on
513 2006-03-26, so releases from before then cannot be used.
514
515 When in doubt about correctness of what configure did, look at the file
516 config.log, which shows all the failed test programs and compiler
517 messages associated with the failures. If that doesn't give a clue,
518 please report the problems, together with the relevant fragments from
519 config.log, as bugs.
520
521 If configure succeeds, but make fails, install the Cygwin port of
522 Bash, even if the table above indicates that Emacs should be able to
523 build without sh.exe. (Some versions of Windows shells are too dumb
524 for Makefile's used by Emacs.)
525
526 If you are using certain Cygwin builds of GCC, such as Cygwin version
527 1.1.8, you may need to specify some extra compiler flags like so:
528
529 configure --with-gcc --cflags -mwin32 --cflags -D__MSVCRT__
530 --ldflags -mwin32
531
532 However, the latest Cygwin versions, such as 1.3.3, don't need those
533 switches; you can simply use "configure --with-gcc".
534
535 We will attempt to auto-detect the need for these flags in a future
536 release.
537
538 * Debugging
539
540 You should be able to debug Emacs using the debugger that is
541 appropriate for the compiler you used, namely DevStudio or Windbg if
542 compiled with MSVC, or GDB if compiled with GCC. (GDB for Windows
543 is available from the MinGW site, http://www.mingw.org/download.shtml.)
544
545 When Emacs aborts due to a fatal internal error, Emacs on Windows
546 pops up an Emacs Abort Dialog asking you whether you want to debug
547 Emacs or terminate it. If Emacs was built with MSVC, click YES
548 twice, and Windbg or the DevStudio debugger will start up
549 automatically. If Emacs was built with GCC, first start GDB and
550 attach it to the Emacs process with the "gdb -p EMACS-PID" command,
551 where EMACS-PID is the Emacs process ID (which you can see in the
552 Windows Task Manager), type the "continue" command inside GDB, and
553 only then click YES on the abort dialog. This will pass control to
554 the debugger, and you will be able to debug the cause of the fatal
555 error.
556
557 Emacs functions implemented in C use a naming convention that reflects
558 their names in lisp. The names of the C routines are the lisp names
559 prefixed with 'F', and with dashes converted to underscores. For
560 example, the function call-process is implemented in C by
561 Fcall_process. Similarly, lisp variables are prefixed with 'V', again
562 with dashes converted to underscores. These conventions enable you to
563 easily set breakpoints or examine familiar lisp variables by name.
564
565 Since Emacs data is often in the form of a lisp object, and the
566 Lisp_Object type is difficult to examine manually in a debugger,
567 Emacs provides a helper routine called debug_print that prints out a
568 readable representation of a Lisp_Object. If you are using GDB,
569 there is a .gdbinit file in the src directory which provides
570 definitions that are useful for examining lisp objects. Therefore,
571 the following tips are mainly of interest when using MSVC.
572
573 The output from debug_print is sent to stderr, and to the debugger
574 via the OutputDebugString routine. The output sent to stderr should
575 be displayed in the console window that was opened when the
576 emacs.exe executable was started. The output sent to the debugger
577 should be displayed in its "Debug" output window.
578
579 When you are in the process of debugging Emacs and you would like to
580 examine the contents of a Lisp_Object variable, pop up the QuickWatch
581 window (QuickWatch has an eyeglass symbol on its button in the
582 toolbar). In the text field at the top of the window, enter
583 debug_print(<variable>) and hit return. For example, start and run
584 Emacs in the debugger until it is waiting for user input. Then click
585 on the Break button in the debugger to halt execution. Emacs should
586 halt in ZwUserGetMessage waiting for an input event. Use the Call
587 Stack window to select the procedure w32_msp_pump up the call stack
588 (see below for why you have to do this). Open the QuickWatch window
589 and enter debug_print(Vexec_path). Evaluating this expression will
590 then print out the contents of the lisp variable exec-path.
591
592 If QuickWatch reports that the symbol is unknown, then check the call
593 stack in the Call Stack window. If the selected frame in the call
594 stack is not an Emacs procedure, then the debugger won't recognize
595 Emacs symbols. Instead, select a frame that is inside an Emacs
596 procedure and try using debug_print again.
597
598 If QuickWatch invokes debug_print but nothing happens, then check the
599 thread that is selected in the debugger. If the selected thread is
600 not the last thread to run (the "current" thread), then it cannot be
601 used to execute debug_print. Use the Debug menu to select the current
602 thread and try using debug_print again. Note that the debugger halts
603 execution (e.g., due to a breakpoint) in the context of the current
604 thread, so this should only be a problem if you've explicitly switched
605 threads.
606
607 \f
608 This file is part of GNU Emacs.
609
610 GNU Emacs is free software: you can redistribute it and/or modify
611 it under the terms of the GNU General Public License as published by
612 the Free Software Foundation, either version 3 of the License, or
613 (at your option) any later version.
614
615 GNU Emacs is distributed in the hope that it will be useful,
616 but WITHOUT ANY WARRANTY; without even the implied warranty of
617 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
618 GNU General Public License for more details.
619
620 You should have received a copy of the GNU General Public License
621 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.