1 GNU make NEWS -*-indented-text-*-
2 History of user-visible changes.
5 See the end of this file for copyrights and conditions.
7 All changes mentioned here are more fully described in the GNU make
8 manual, which is contained in this distribution as the file doc/make.texi.
9 See the README file and the GNU make manual for instructions for
14 A complete list of bugs fixed in this version is available here:
16 http://sv.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=101&set=custom
18 * New command line option: --trace enables tracing of targets. When enabled
19 the recipe to be invoked is printed even if it would otherwise be suppressed
20 by .SILENT or a "@" prefix character. Also before each recipe is run the
21 makefile name and linenumber where it was defined are shown as well as the
22 prerequisites that caused the target to be considered out of date.
24 * On failure, the makefile name and linenumber of the recipe that failed are
30 A complete list of bugs fixed in this version is available here:
32 http://sv.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=104&set=custom
34 * Compiling GNU make now requires a conforming ISO C 1989 compiler and
35 standard runtime library.
37 * WARNING: Backward-incompatibility!
38 The POSIX standard for make was changed in the 2008 version in a
39 fundamentally incompatible way: make is required to invoke the shell as if
40 the '-e' flag were provided. Because this would break many makefiles that
41 have been written to conform to the original text of the standard, the
42 default behavior of GNU make remains to invoke the shell with simply '-c'.
43 However, any makefile specifying the .POSIX special target will follow the
44 new POSIX standard and pass '-e' to the shell. See also .SHELLFLAGS
47 * WARNING: Backward-incompatibility!
48 The '$?' variable now contains all prerequisites that caused the target to
49 be considered out of date, even if they do not exist (previously only
50 existing targets were provided in $?).
52 * WARNING: Backward-incompatibility!
53 Wildcards were not documented as returning sorted values, but the results
54 have been sorted up until this release.. If your makefiles require sorted
55 results from wildcard expansions, use the $(sort ...) function to request
58 * WARNING: Backward-incompatibility!
59 In previous versions of make it was acceptable to list one or more explicit
60 targets followed by one or more pattern targets in the same rule and it
61 worked "as expected". However, this was not documented as acceptable and if
62 you listed any explicit targets AFTER the pattern targets, the entire rule
63 would be mis-parsed. This release removes this ability completely: make
64 will generate an error message if you mix explicit and pattern targets in
67 * WARNING: Backward-incompatibility!
68 As a result of parser enhancements, three backward-compatibility issues
69 exist: first, a prerequisite containing an "=" cannot be escaped with a
70 backslash any longer. You must create a variable containing an "=" and
71 use that variable in the prerequisite. Second, variable names can no
72 longer contain whitespace, unless you put the whitespace in a variable and
73 use the variable. Third, in previous versions of make it was sometimes
74 not flagged as an error for explicit and pattern targets to appear in the
75 same rule. Now this is always reported as an error.
77 * WARNING: Backward-incompatibility!
78 The pattern-specific variables and pattern rules are now applied in the
79 shortest stem first order instead of the definition order (variables
80 and rules with the same stem length are still applied in the definition
81 order). This produces the usually-desired behavior where more specific
82 patterns are preferred. To detect this feature search for 'shortest-stem'
83 in the .FEATURES special variable.
85 * WARNING: Backward-incompatibility!
86 The library search behavior has changed to be compatible with the standard
87 linker behavior. Prior to this version for prerequisites specified using
88 the -lfoo syntax make first searched for libfoo.so in the current
89 directory, vpath directories, and system directories. If that didn't yield
90 a match, make then searched for libfoo.a in these directories. Starting
91 with this version make searches first for libfoo.so and then for libfoo.a
92 in each of these directories in order.
94 * New command line option: --eval=STRING causes STRING to be evaluated as
95 makefile syntax (akin to using the $(eval ...) function). The evaluation
96 is performed after all default rules and variables are defined, but before
97 any makefiles are read.
99 * New special variable: .RECIPEPREFIX allows you to reset the recipe
100 introduction character from the default (TAB) to something else. The
101 first character of this variable value is the new recipe introduction
102 character. If the variable is set to the empty string, TAB is used again.
103 It can be set and reset at will; recipes will use the value active when
104 they were first parsed. To detect this feature check the value of
107 * New special variable: .SHELLFLAGS allows you to change the options passed
108 to the shell when it invokes recipes. By default the value will be "-c"
109 (or "-ec" if .POSIX is set).
111 * New special target: .ONESHELL instructs make to invoke a single instance
112 of the shell and provide it with the entire recipe, regardless of how many
113 lines it contains. As a special feature to allow more straightforward
114 conversion of makefiles to use .ONESHELL, any recipe line control
115 characters ('@', '+', or '-') will be removed from the second and
116 subsequent recipe lines. This happens _only_ if the SHELL value is deemed
117 to be a standard POSIX-style shell. If not, then no interior line control
118 characters are removed (as they may be part of the scripting language used
119 with the alternate SHELL).
121 * New variable modifier 'private': prefixing a variable assignment with the
122 modifier 'private' suppresses inheritance of that variable by
123 prerequisites. This is most useful for target- and pattern-specific
126 * New make directive: 'undefine' allows you to undefine a variable so that
127 it appears as if it was never set. Both $(flavor) and $(origin) functions
128 will return 'undefined' for such a variable. To detect this feature search
129 for 'undefine' in the .FEATURES special variable.
131 * The parser for variable assignments has been enhanced to allow multiple
132 modifiers ('export', 'override', 'private') on the same line as variables,
133 including define/endef variables, and in any order. Also, it is possible
134 to create variables and targets named as these modifiers.
136 * The 'define' make directive now allows a variable assignment operator
137 after the variable name, to allow for simple, conditional, or appending
138 multi-line variable assignment.
143 * GNU make is ported to OS/2.
145 * GNU make is ported to MinGW. The MinGW build is only supported by
146 the build_w32.bat batch file; see the file README.W32 for more
149 * WARNING: Future backward-incompatibility!
150 Up to and including this release, the '$?' variable does not contain
151 any prerequisite that does not exist, even though that prerequisite
152 might have caused the target to rebuild. Starting with the _next_
153 release of GNU make, '$?' will contain all prerequisites that caused
154 the target to be considered out of date. See this Savannah bug:
155 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
157 * WARNING: Backward-incompatibility!
158 GNU make now implements a generic "second expansion" feature on the
159 prerequisites of both explicit and implicit (pattern) rules. In order
160 to enable this feature, the special target '.SECONDEXPANSION' must be
161 defined before the first target which takes advantage of it. If this
162 feature is enabled then after all rules have been parsed the
163 prerequisites are expanded again, this time with all the automatic
164 variables in scope. This means that in addition to using standard
165 SysV $$@ in prerequisites lists, you can also use complex functions
166 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
167 as well, where the second expansion occurs when the rule is matched.
168 However, this means that when '.SECONDEXPANSION' is enabled you must
169 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
170 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
171 which used to be available by default, is now ONLY available when the
172 .SECONDEXPANSION target is defined. If your makefiles take advantage
173 of this SysV feature you will need to update them.
175 * WARNING: Backward-incompatibility!
176 In order to comply with POSIX, the way in which GNU make processes
177 backslash-newline sequences in recipes has changed. If your makefiles
178 use backslash-newline sequences inside of single-quoted strings in
179 recipes you will be impacted by this change. See the GNU make manual
180 subsection "Splitting Recipe Lines" (node "Splitting Lines"), in
181 section "Recipe Syntax", chapter "Writing Recipe in Rules", for
184 * WARNING: Backward-incompatibility!
185 Some previous versions of GNU make had a bug where "#" in a function
186 invocation such as $(shell ...) was treated as a make comment. A
187 workaround was to escape these with backslashes. This bug has been
188 fixed: if your makefile uses "\#" in a function invocation the
189 backslash is now preserved, so you'll need to remove it.
191 * New command line option: -L (--check-symlink-times). On systems that
192 support symbolic links, if this option is given then GNU make will
193 use the most recent modification time of any symbolic links that are
194 used to resolve target files. The default behavior remains as it
195 always has: use the modification time of the actual target file only.
197 * The "else" conditional line can now be followed by any other valid
198 conditional on the same line: this does not increase the depth of the
199 conditional nesting, so only one "endif" is required to close the
202 * All pattern-specific variables that match a given target are now used
203 (previously only the first match was used).
205 * Target-specific variables can be marked as exportable using the
208 * In a recursive $(call ...) context, any extra arguments from the outer
209 call are now masked in the context of the inner call.
211 * Implemented a solution for the "thundering herd" problem with "-j -l".
212 This version of GNU make uses an algorithm suggested by Thomas Riedl
213 <thomas.riedl@siemens.com> to track the number of jobs started in the
214 last second and artificially adjust GNU make's view of the system's
215 load average accordingly.
217 * New special variables available in this release:
218 - .INCLUDE_DIRS: Expands to a list of directories that make searches
219 for included makefiles.
220 - .FEATURES: Contains a list of special features available in this
222 - .DEFAULT_GOAL: Set the name of the default goal make will
223 use if no goals are provided on the command line.
224 - MAKE_RESTARTS: If set, then this is the number of times this
225 instance of make has been restarted (see "How Makefiles Are Remade"
227 - New automatic variable: $| (added in 3.80, actually): contains all
228 the order-only prerequisites defined for the target.
230 * New functions available in this release:
231 - $(lastword ...) returns the last word in the list. This gives
232 identical results as $(word $(words ...) ...), but is much faster.
233 - $(abspath ...) returns the absolute path (all "." and ".."
234 directories resolved, and any duplicate "/" characters removed) for
236 - $(realpath ...) returns the canonical pathname for each path
237 provided. The canonical pathname is the absolute pathname, with
238 all symbolic links resolved as well.
239 - $(info ...) prints its arguments to stdout. No makefile name or
240 line number info, etc. is printed.
241 - $(flavor ...) returns the flavor of a variable.
242 - $(or ...) provides a short-circuiting OR conditional: each argument
243 is expanded. The first true (non-empty) argument is returned; no
244 further arguments are expanded. Expands to empty if there are no
246 - $(and ...) provides a short-circuiting AND conditional: each
247 argument is expanded. The first false (empty) argument is
248 returned; no further arguments are expanded. Expands to the last
249 argument if all arguments are true.
251 * Changes made for POSIX compatibility:
252 - Only touch targets (under -t) if they have a recipe.
253 - Setting the SHELL make variable does NOT change the value of the
254 SHELL environment variable given to programs invoked by make. As
255 an enhancement to POSIX, if you export the make variable SHELL then
256 it will be set in the environment, just as before.
258 * On MS Windows systems, explicitly setting SHELL to a pathname ending
259 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
260 the DOS command interpreter in batch mode even if a UNIX-like shell
261 could be found on the system.
263 * On VMS there is now support for case-sensitive filesystems such as ODS5.
264 See the readme.vms file for information.
266 * Parallel builds (-jN) no longer require a working Bourne shell on
267 Windows platforms. They work even with the stock Windows shells, such
268 as cmd.exe and command.com.
270 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
271 should not be impacted.
273 * New translations for Swedish, Chinese (simplified), Ukrainian,
274 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
277 A complete list of bugs fixed in this version is available here:
279 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
284 * A new feature exists: order-only prerequisites. These prerequisites
285 affect the order in which targets are built, but they do not impact
286 the rebuild/no-rebuild decision of their dependents. That is to say,
287 they allow you to require target B be built before target A, without
288 requiring that target A will always be rebuilt if target B is updated.
289 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
291 * For compatibility with SysV make, GNU make now supports the peculiar
292 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
293 This syntax is only valid within explicit and static pattern rules: it
294 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
295 <egp@free.fr> provided a patch implementing this feature; however, I
296 decided to implement it in a different way.
298 * The argument to the "ifdef" conditional is now expanded before it's
299 tested, so it can be a constructed variable name.
301 Similarly, the arguments to "export" (when not used in a variable
302 definition context) and "unexport" are also now expanded.
304 * A new function is defined: $(value ...). The argument to this
305 function is the _name_ of a variable. The result of the function is
306 the value of the variable, without having been expanded.
308 * A new function is defined: $(eval ...). The arguments to this
309 function should expand to makefile commands, which will then be
310 evaluated as if they had appeared in the makefile. In combination
311 with define/endef multiline variable definitions this is an extremely
312 powerful capability. The $(value ...) function is also sometimes
315 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
316 list of each makefile GNU make has read, or started to read, in the
317 order in which they were encountered. So, the last filename in the
318 list when a makefile is just being read (before any includes) is the
319 name of the current makefile.
321 * A new built-in variable is defined: $(.VARIABLES). When it is
322 expanded it returns a complete list of variable names defined by all
323 makefiles at that moment.
325 * A new command line option is defined, -B or --always-make. If
326 specified GNU make will consider all targets out-of-date even if they
327 would otherwise not be.
329 * The arguments to $(call ...) functions were being stored in $1, $2,
330 etc. as recursive variables, even though they are fully expanded
331 before assignment. This means that escaped dollar signs ($$ etc.)
332 were not behaving properly. Now the arguments are stored as simple
333 variables. This may mean that if you added extra escaping to your
334 $(call ...) function arguments you will need to undo it now.
336 * The variable invoked by $(call ...) can now be recursive: unlike other
337 variables it can reference itself and this will not produce an error
338 when it is used as the first argument to $(call ...) (but only then).
340 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
341 option --disable-nsec-timestamps. You might need this if your build
342 process depends on tools like "cp -p" preserving time stamps, since
343 "cp -p" (right now) doesn't preserve the subsecond portion of a time
346 * Updated translations for French, Galician, German, Japanese, Korean,
347 and Russian. New translations for Croatian, Danish, Hebrew, and
350 * Updated internationalization support to Gettext 0.11.5.
351 GNU make now uses Gettext's "external" feature, and does not include
352 any internationalization code itself. Configure will search your
353 system for an existing implementation of GNU Gettext (only GNU Gettext
354 is acceptable) and use it if it exists. If not, NLS will be disabled.
355 See ABOUT-NLS for more information.
357 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
359 A complete list of bugs fixed in this version is available here:
361 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
366 * .SECONDARY with no prerequisites now prevents any target from being
367 removed because make thinks it's an intermediate file, not just those
368 listed in the makefile.
370 * New configure option --disable-nsec-timestamps, but this was
371 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
375 * GNU make optionally supports internationalization and locales via the
376 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
377 file for more information on configuring GNU make for NLS.
379 * Previously, GNU make quoted variables such as MAKEFLAGS and
380 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
381 be used within make build scripts. However, using them there is not
382 proper behavior: they are meant to be passed to subshells via the
383 environment. Unfortunately the values were not quoted properly to be
384 passed through the environment. This meant that make didn't properly
385 pass some types of command line values to submakes.
387 With this version we change that behavior: now these variables are
388 quoted properly for passing through the environment, which is the
389 correct way to do it. If you previously used these variables
390 explicitly within a make rule you may need to re-examine your use for
391 correctness given this change.
393 * A new pseudo-target .NOTPARALLEL is available. If defined, the
394 current makefile is run serially regardless of the value of -j.
395 However, submakes are still eligible for parallel execution.
397 * The --debug option has changed: it now allows optional flags
398 controlling the amount and type of debugging output. By default only
399 a minimal amount information is generated, displaying the names of
400 "normal" targets (not makefiles) that were deemed out of date and in
401 need of being rebuilt.
403 Note that the -d option behaves as before: it takes no arguments and
404 all debugging information is generated.
406 * The `-p' (print database) output now includes filename and linenumber
407 information for variable definitions, to aid debugging.
409 * The wordlist function no longer reverses its arguments if the "start"
410 value is greater than the "end" value. If that's true, nothing is
413 * Hartmut Becker provided many updates for the VMS port of GNU make.
414 See the readme.vms file for more details.
418 * Two new functions, $(error ...) and $(warning ...) are available. The
419 former will cause make to fail and exit immediately upon expansion of
420 the function, with the text provided as the error message. The latter
421 causes the text provided to be printed as a warning message, but make
424 * A new function $(call ...) is available. This allows users to create
425 their own parameterized macros and invoke them later. Original
426 implementation of this function was provided by Han-Wen Nienhuys
429 * A new function $(if ...) is available. It provides if-then-else
430 capabilities in a builtin function. Original implementation of this
431 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
433 * Make defines a new variable, .LIBPATTERNS. This variable controls how
434 library dependency expansion (dependencies like ``-lfoo'') is performed.
436 * Make accepts CRLF sequences as well as traditional LF, for
437 compatibility with makefiles created on other operating systems.
439 * Make accepts a new option: -R, or --no-builtin-variables. This option
440 disables the definition of the rule-specific builtin variables (CC,
441 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
444 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
446 On systems that support POSIX pipe(2) semantics, GNU make can now pass
447 -jN options to submakes rather than forcing them all to use -j1. The
448 top make and all its sub-make processes use a pipe to communicate with
449 each other to ensure that no more than N jobs are started across all
450 makes. To get the old behavior of -j back, you can configure make
451 with the --disable-job-server option.
453 * The confusing term "dependency" has been replaced by the more accurate
454 and standard term "prerequisite", both in the manual and in all GNU make
457 * GNU make supports the "big archive" library format introduced in AIX 4.3.
459 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
460 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
461 support for Solaris and Linux was introduced in 3.77, but the
462 configuration had issues: these have also been resolved).
464 * The Windows 95/98/NT (W32) version of GNU make now has native support
465 for the Cygnus Cygwin release B20.1 shell (bash).
467 * The GNU make regression test suite, long available separately "under
468 the table", has been integrated into the release. You can invoke it
469 by running "make check" in the distribution. Note that it requires
470 Perl (either Perl 4 or Perl 5) to run.
474 * Implement BSD make's "?=" variable assignment operator. The variable
475 is assigned the specified value only if that variable is not already
478 * Make defines a new variable, "CURDIR", to contain the current working
479 directory (after the -C option, if any, has been processed).
480 Modifying this variable has no effect on the operation of make.
482 * Make defines a new default RCS rule, for new-style master file
483 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
485 Make defines new default rules for DOS-style C++ file naming
486 conventions, with ``.cpp'' suffixes. All the same rules as for
487 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
488 COMPILE.cpp macros (which default to the same value as LINK.cc and
489 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
490 use CXXFLAGS to change C++ compiler flags.
492 * A new feature, "target-specific variable values", has been added.
493 This is a large change so please see the appropriate sections of the
494 manual for full details. Briefly, syntax like this:
496 TARGET: VARIABLE = VALUE
498 defines VARIABLE as VALUE within the context of TARGET. This is
499 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
500 that the assignment may be of any type, not just recursive, and that
501 the override keyword is available.
503 COMPATIBILITY: This new syntax means that if you have any rules where
504 the first or second dependency has an equal sign (=) in its name,
505 you'll have to escape them with a backslash: "foo : bar\=baz".
506 Further, if you have any dependencies which already contain "\=",
507 you'll have to escape both of them: "foo : bar\\\=baz".
509 * A new appendix listing the most common error and warning messages
510 generated by GNU make, with some explanation, has been added to the
511 GNU make User's Manual.
513 * Updates to the GNU make Customs library support (see README.customs).
515 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
516 and to the DOS port from Eli Zaretski (see README.DOS).
520 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
524 * GNU make now uses automake to control Makefile.in generation. This
525 should make it more consistent with the GNU standards.
527 * VPATH functionality has been changed to incorporate the VPATH+ patch,
528 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
531 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
532 were specified on the command line, if any. Modifying this variable
533 has no effect on the operation of make.
535 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
536 list of words from number S to number E (inclusive) of TEXT.
538 * Instead of an error, detection of future modification times gives a
539 warning and continues. The warning is repeated just before GNU make
540 exits, so it is less likely to be lost.
542 * Fix the $(basename) and $(suffix) functions so they only operate on
543 the last filename, not the entire string:
545 Command Old Result New Result
546 ------- ---------- ----------
548 $(basename a.b/c) a a.b/c
550 $(suffix a.b/c) b/c <empty>
552 * The $(strip) function now removes newlines as well as TABs and spaces.
554 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
557 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
559 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
560 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
561 and utilities. See README.DOS for details, and direct all questions
562 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
563 Delorie <dj@delorie.com>.
565 * John W. Eaton has updated the VMS port to support libraries and VPATH.
569 * The directory messages printed by `-w' and implicitly in sub-makes,
570 are now omitted if Make runs no commands and has no other messages to print.
572 * Make now detects files that for whatever reason have modification times
573 in the future and gives an error. Files with such impossible timestamps
574 can result from unsynchronized clocks, or archived distributions
575 containing bogus timestamps; they confuse Make's dependency engine
578 * The new directive `sinclude' is now recognized as another name for
579 `-include', for compatibility with some other Makes.
581 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
582 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
584 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
585 See README.W32 for details, and direct all Windows-related questions to
586 <rob_tulloh@tivoli.com>.
590 * Converted to use Autoconf version 2, so `configure' has some new options.
591 See INSTALL for details.
593 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
594 output enabled by -d, at any time during the run.
598 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
599 He is maintaining the DOS port, not the GNU Make maintainer;
600 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
601 MS-DOS binaries are available for FTP from ftp.simtel.net in
602 /pub/simtelnet/gnu/djgpp/.
604 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
605 contain variable definitions itself; these are treated just like
606 command line variable definitions. Make will automatically insert any
607 variable definitions from the environment value of `MAKEFLAGS' or from
608 the command line, into the `MAKEFLAGS' value exported to children. The
609 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
610 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
611 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
612 in the environment when its size is limited.
614 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
615 a rule if it has changed when its recipe exits with a nonzero status,
616 just as when the recipe gets a signal.
618 * The automatic variable `$+' is new. It lists all the dependencies like
619 `$^', but preserves duplicates listed in the makefile. This is useful
620 for linking rules, where library files sometimes need to be listed twice
623 * You can now specify the `.IGNORE' and `.SILENT' special targets with
624 dependencies to limit their effects to those files. If a file appears as
625 a dependency of `.IGNORE', then errors will be ignored while running the
626 recipe to update that file. Likewise if a file appears as a dependency
627 of `.SILENT', then the recipe to update that file will not be printed
628 before it is run. (This change was made to conform to POSIX.2.)
632 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
633 `$(^D)' now omit the trailing slash from the directory name. (This change
634 was made to comply with POSIX.2.)
636 * The source distribution now includes the Info files for the Make manual.
637 There is no longer a separate distribution containing Info and DVI files.
639 * You can now set the variables `binprefix' and/or `manprefix' in
640 Makefile.in (or on the command line when installing) to install GNU make
641 under a name other than `make' (i.e., ``make binprefix=g install''
642 installs GNU make as `gmake').
644 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
645 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
648 * The exit status of Make when it runs into errors is now 2 instead of 1.
649 The exit status is 1 only when using -q and some target is not up to date.
650 (This change was made to comply with POSIX.2.)
654 * It is no longer a fatal error to have a NUL character in a makefile.
655 You should never put a NUL in a makefile because it can have strange
656 results, but otherwise empty lines full of NULs (such as produced by
657 the `xmkmf' program) will always work fine.
659 * The error messages for nonexistent included makefiles now refer to the
660 makefile name and line number where the `include' appeared, so Emacs's
661 C-x ` command takes you there (in case it's a typo you need to fix).
665 * Implicit rule search for archive member references is now done in the
666 opposite order from previous versions: the whole target name `LIB(MEM)'
667 first, and just the member name and parentheses `(MEM)' second.
669 * Make now gives an error for an unterminated variable or function reference.
670 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
672 * The new default variable `MAKE_VERSION' gives the version number of
673 Make, and a string describing the remote job support compiled in (if any).
674 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
676 * Commands in an invocation of the `shell' function are no longer run
677 with a modified environment like recipes are. As in versions before
678 3.68, they now run with the environment that `make' started with. We
679 have reversed the change made in version 3.68 because it turned out to
680 cause a paradoxical situation in cases like:
682 export variable = $(shell echo value)
684 When Make attempted to put this variable in the environment for a
685 recipe, it would try expand the value by running the shell command
686 `echo value'. In version 3.68, because it constructed an environment
687 for that shell command in the same way, Make would begin to go into an
688 infinite loop and then get a fatal error when it detected the loop.
690 * The recipe given for `.DEFAULT' is now used for phony targets with no
695 * You can list several archive member names inside parenthesis:
696 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
698 * You can use wildcards inside archive member references. For example,
699 `lib(*.o)' expands to all existing members of `lib' whose names end in
700 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
701 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
702 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
704 * A suffix rule `.X.a' now produces two pattern rules:
705 (%.o): %.X # Previous versions produced only this.
706 %.a: %.X # Now produces this as well, just like other suffixes.
708 * The new flag `--warn-undefined-variables' says to issue a warning message
709 whenever Make expands a reference to an undefined variable.
711 * The new `-include' directive is just like `include' except that there is
712 no error (not even a warning) for a nonexistent makefile.
714 * Commands in an invocation of the `shell' function are now run with a
715 modified environment like recipes are, so you can use `export' et al
716 to set up variables for them. They used to run with the environment
717 that `make' started with.
721 * `make --version' (or `make -v') now exits immediately after printing
726 * Make now supports long-named members in `ar' archive files.
730 * Make now supports the `+=' syntax for a variable definition which appends
731 to the variable's previous value. See the section `Appending More Text
732 to Variables' in the manual for full details.
734 * The new option `--no-print-directory' inhibits the `-w' or
735 `--print-directory' feature. Make turns on `--print-directory'
736 automatically if you use `-C' or `--directory', and in sub-makes; some
737 users have found this behavior undesirable.
739 * The built-in implicit rules now support the alternative extension
740 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
744 * Make now uses a standard GNU `configure' script. See the new file
745 INSTALL for the new (and much simpler) installation procedure.
747 * There is now a shell script to build Make the first time, if you have no
748 other `make' program. `build.sh' is created by `configure'; see README.
750 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
752 * Elements of the `$^' and `$?' automatic variables that are archive
753 member references now list only the member name, as in Unix and POSIX.2.
755 * You should no longer ever need to specify the `-w' switch, which prints
756 the current directory before and after Make runs. The `-C' switch to
757 change directory, and recursive use of Make, now set `-w' automatically.
759 * Multiple double-colon rules for the same target will no longer have their
760 recipes run simultaneously under -j, as this could result in the two
761 recipes trying to change the file at the same time and interfering with
764 * The `SHELL' variable is now never taken from the environment.
765 Each makefile that wants a shell other than the default (/bin/sh) must
766 set SHELL itself. SHELL is always exported to child processes.
767 This change was made for compatibility with POSIX.2.
769 * Make now accepts long options. There is now an informative usage message
770 that tells you what all the options are and what they do. Try `make --help'.
772 * There are two new directives: `export' and `unexport'. All variables are
773 no longer automatically put into the environments of the recipe lines that
774 Make runs. Instead, only variables specified on the command line or in
775 the environment are exported by default. To export others, use:
777 or you can define variables with:
778 export VARIABLE = VALUE
780 export VARIABLE := VALUE
784 .EXPORT_ALL_VARIABLES:
785 to get the old behavior. See the node `Variables/Recursion' in the manual
786 for a full description.
788 * The recipe from the `.DEFAULT' special target is only applied to
789 targets which have no rules at all, not all targets with no recipe.
790 This change was made for compatibility with Unix make.
792 * All fatal error messages now contain `***', so they are easy to find in
795 * Dependency file names like `-lNAME' are now replaced with the actual file
796 name found, as with files found by normal directory search (VPATH).
797 The library file `libNAME.a' may now be found in the current directory,
798 which is checked before VPATH; the standard set of directories (/lib,
799 /usr/lib, /usr/local/lib) is now checked last.
800 See the node `Libraries/Search' in the manual for full details.
802 * A single `include' directive can now specify more than one makefile to
805 You can also use shell file name patterns in an `include' directive:
808 * The default directories to search for included makefiles, and for
809 libraries specified with `-lNAME', are now set by configuration.
811 * You can now use blanks as well as colons to separate the directories in a
812 search path for the `vpath' directive or the `VPATH' variable.
814 * You can now use variables and functions in the left hand side of a
815 variable assignment, as in "$(foo)bar = value".
817 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
818 The `MAKE_COMMAND' variable is now defined to the name with which make
821 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
822 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
823 problems with shells that cannot have `+' in environment variable names.
825 * The value of a recursively expanded variable is now expanded when putting
826 it into the environment for child processes. This change was made for
827 compatibility with Unix make.
829 * A rule with no targets before the `:' is now accepted and ignored.
830 This change was made for compatibility with SunOS 4 make.
831 We do not recommend that you write your makefiles to take advantage of this.
833 * The `-I' switch can now be used in MAKEFLAGS, and are put there
834 automatically just like other switches.
838 * Built-in rules for C++ source files with the `.C' suffix.
839 We still recommend that you use `.cc' instead.
841 * If a recipe is given too many times for a single target, the last one
842 given is used, and a warning message is printed.
844 * Error messages about makefiles are in standard GNU error format,
845 so C-x ` in Emacs works on them.
847 * Dependencies of pattern rules which contain no % need not actually exist
848 if they can be created (just like dependencies which do have a %).
852 * A message is always printed when Make decides there is nothing to be done.
853 It used to be that no message was printed for top-level phony targets
854 (because "`phony' is up to date" isn't quite right). Now a different
855 message "Nothing to be done for `phony'" is printed in that case.
857 * Archives on AIX now supposedly work.
859 * When the recipes specified for .DEFAULT are used to update a target,
860 the $< automatic variable is given the same value as $@ for that target.
861 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
865 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
866 variables while remaking makefiles, so recursive makes done while remaking
867 makefiles will behave properly.
869 * If the special target `.NOEXPORT' is specified in a makefile,
870 only variables that came from the environment and variables
871 defined on the command line are exported.
875 * Suffix rules may have dependencies (which are ignored).
879 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
880 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
884 * There is now a Unix man page for GNU Make. It is certainly not a
885 replacement for the Texinfo manual, but it documents the basic
886 functionality and the switches. For full documentation, you should
887 still read the Texinfo manual. Thanks to Dennis Morse of Stanford
888 University for contributing the initial version of this.
890 * Variables which are defined by default (e.g., `CC') will no longer be
891 put into the environment for child processes. (If these variables are
892 reset by the environment, makefiles, or the command line, they will
893 still go into the environment.)
895 * Makefiles which have recipes but no dependencies (and thus are always
896 considered out of date and in need of remaking), will not be remade (if they
897 were being remade only because they were makefiles). This means that GNU
898 Make will no longer go into an infinite loop when fed the makefiles that
899 `imake' (necessary to build X Windows) produces.
901 * There is no longer a warning for using the `vpath' directive with an explicit
902 pathname (instead of a `%' pattern).
906 * When removing intermediate files, only one `rm' command line is printed,
907 listing all file names.
909 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
910 These are the directory-only and file-only versions of `$^' and `$?'.
912 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
913 directory if it exists.
915 * The automatic variable `$($/)' is no longer defined.
917 * Leading `+' characters on a recipe line make that line be executed even
918 under -n, -t, or -q (as if the line contained `$(MAKE)').
920 * For recipe lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
921 only those lines are executed, not the entire recipe.
922 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
926 * Filenames in rules will now have ~ and ~USER expanded.
928 * The `-p' output has been changed so it can be used as a makefile.
929 (All information that isn't specified by makefiles is prefaced with comment
934 * The % character can be quoted with backslash in implicit pattern rules,
935 static pattern rules, `vpath' directives, and `patsubst', `filter', and
936 `filter-out' functions. A warning is issued if a `vpath' directive's
937 pattern contains no %.
939 * The `wildcard' variable expansion function now expands ~ and ~USER.
941 * Messages indicating failed recipe lines now contain the target name:
942 make: *** [target] Error 1
944 * The `-p' output format has been changed somewhat to look more like
945 makefile rules and to give all information that Make has about files.
951 * The `-l' switch with no argument removes any previous load-average limit.
953 * When the `-w' switch is in effect, and Make has updated makefiles,
954 it will write a `Leaving directory' message before re-executing itself.
955 This makes the `directory change tracking' changes to Emacs's compilation
956 commands work properly.
960 * The automatic variable `$*' is now defined for explicit rules,
961 as it is in Unix make.
965 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
966 specified without an argument (indicating infinite jobs).
967 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
969 * Make no longer checks hashed directories after running recipes.
970 The behavior implemented in 3.41 caused too much slowdown.
974 * A dependency is NOT considered newer than its dependent if
975 they have the same modification time. The behavior implemented
976 in 3.43 conflicts with RCS.
980 * Dependency loops are no longer fatal errors.
982 * A dependency is considered newer than its dependent if
983 they have the same modification time.
987 * The variables F77 and F77FLAGS are now set by default to $(FC) and
988 $(FFLAGS). Makefiles designed for System V make may use these variables in
989 explicit rules and expect them to be set. Unfortunately, there is no way to
990 make setting these affect the Fortran implicit rules unless FC and FFLAGS
991 are not used (and these are used by BSD make).
995 * Make now checks to see if its hashed directories are changed by recipes.
996 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
1000 * The `shell' function no longer captures standard error output.
1004 * A file beginning with a dot can be the default target if it also contains
1005 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
1009 * Archive member names are truncated to 15 characters.
1011 * Yet more USG stuff.
1013 * Minimal support for Microport System V (a 16-bit machine and a
1014 brain-damaged compiler). This has even lower priority than other USG
1015 support, so if it gets beyond trivial, I will take it out completely.
1017 * Revamped default implicit rules (not much visible change).
1019 * The -d and -p options can come from the environment.
1023 * Improved support for USG and HPUX (hopefully).
1025 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
1026 equivalent to `$(patsubst a,b,$(foo))'.
1028 * Defining .DEFAULT with no deps or recipe clears its recipe.
1030 * New default implicit rules for .S (cpp, then as), and .sh (copy and
1031 make executable). All default implicit rules that use cpp (even
1032 indirectly), use $(CPPFLAGS).
1036 * Giving the -j option with no arguments gives you infinite jobs.
1040 * New option: "-l LOAD" says not to start any new jobs while others are
1041 running if the load average is not below LOAD (a floating-point number).
1043 * There is support in place for implementations of remote command execution
1044 in Make. See the file remote.c.
1048 * No more than 10 directories will be kept open at once.
1049 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
1053 * Archive files will have their modification times recorded before doing
1054 anything that might change their modification times by updating an archive
1059 * The `MAKELEVEL' variable is defined for use by makefiles.
1063 * The recursion level indications in error messages are much shorter than
1064 they were in version 3.14.
1068 * Leading spaces before directives are ignored (as documented).
1070 * Included makefiles can determine the default goal target.
1071 (System V Make does it this way, so we are being compatible).
1075 * Variables that are defaults built into Make will not be put in the
1076 environment for children. This just saves some environment space and,
1077 except under -e, will be transparent to sub-makes.
1079 * Error messages from sub-makes will indicate the level of recursion.
1081 * Hopefully some speed-up for large directories due to a change in the
1082 directory hashing scheme.
1084 * One child will always get a standard input that is usable.
1086 * Default makefiles that don't exist will be remade and read in.
1090 * Count parentheses inside expansion function calls so you can
1091 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
1095 * Several bug fixes, including USG and Sun386i support.
1097 * `shell' function to expand shell commands a la `
1099 * If the `-d' flag is given, version information will be printed.
1101 * The `-c' option has been renamed to `-C' for compatibility with tar.
1103 * The `-p' option no longer inhibits other normal operation.
1105 * Makefiles will be updated and re-read if necessary.
1107 * Can now run several recipes at once (parallelism), -j option.
1109 * Error messages will contain the level of Make recursion, if any.
1111 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
1114 * A double-colon rule with no dependencies will always have its recipe run.
1115 (This is how both the BSD and System V versions of Make do it.)
1119 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
1121 -------------------------------------------------------------------------------
1122 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1123 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
1124 2010 Free Software Foundation, Inc. This file is part of GNU Make.
1126 GNU Make is free software; you can redistribute it and/or modify it under the
1127 terms of the GNU General Public License as published by the Free Software
1128 Foundation; either version 3 of the License, or (at your option) any later
1131 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1132 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1133 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1135 You should have received a copy of the GNU General Public License along with
1136 this program. If not, see <http://www.gnu.org/licenses/>.