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 * WARNING: Backward-incompatibility!
19 If .POSIX is specified, then make adheres to the POSIX backslash/newline
20 handling requirements, which introduces the following changes to the
21 standard backslash/newline handling in non-recipe lines:
22 * Any trailing space before the backslash is preserved
23 * Each backslash/newline (plus subsequent whitespace) is converted to a
26 * New command line option: --trace enables tracing of targets. When enabled
27 the recipe to be invoked is printed even if it would otherwise be suppressed
28 by .SILENT or a "@" prefix character. Also before each recipe is run the
29 makefile name and linenumber where it was defined are shown as well as the
30 prerequisites that caused the target to be considered out of date.
32 * New feature: The "job server" capability is now supported on Windows.
33 Implementation contributed by Troy Runkel <Troy.Runkel@mathworks.com>
35 * New feature: "!=" shell assignment operator as an alternative to the
36 $(shell ...) function. Implemented for compatibility with BSD makefiles.
37 WARNING: Backward-incompatibility!
38 Variables ending in "!" previously defined as "variable!= value" will now be
39 interpreted as shell assignment. Change your assignment to add whitespace
40 between the "!" and "=": "variable! = value"
42 * New feature: "::=" simple assignment operator as defined by POSIX in 2012.
43 This operator has identical functionality to ":=" in GNU make, but will be
44 portable to any implementation of make conforming to a sufficiently new
45 version of POSIX (see http://austingroupbugs.net/view.php?id=330). It is
46 not necessary to define the .POSIX target to access this operator.
48 * New feature: GNU Guile integration
49 This version of GNU make can be compiled with GNU Guile integration.
50 GNU Guile serves as an embedded extension language for make.
51 See the "Guile Function" section in the GNU Make manual for details.
53 * New function: $(file ...) writes to a file.
55 * On failure, the makefile name and linenumber of the recipe that failed are
58 * A .RECIPEPREFIX setting is remembered per-recipe and variables expanded
59 in that recipe also use that recipe prefix setting.
61 * In -p output, .RECIPEPREFIX settings are shown and all target-specific
62 variables are output as if in a makefile, instead of as comments.
67 A complete list of bugs fixed in this version is available here:
69 http://sv.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=104&set=custom
71 * Compiling GNU make now requires a conforming ISO C 1989 compiler and
72 standard runtime library.
74 * WARNING: Backward-incompatibility!
75 The POSIX standard for make was changed in the 2008 version in a
76 fundamentally incompatible way: make is required to invoke the shell as if
77 the '-e' flag were provided. Because this would break many makefiles that
78 have been written to conform to the original text of the standard, the
79 default behavior of GNU make remains to invoke the shell with simply '-c'.
80 However, any makefile specifying the .POSIX special target will follow the
81 new POSIX standard and pass '-e' to the shell. See also .SHELLFLAGS
84 * WARNING: Backward-incompatibility!
85 The '$?' variable now contains all prerequisites that caused the target to
86 be considered out of date, even if they do not exist (previously only
87 existing targets were provided in $?).
89 * WARNING: Backward-incompatibility!
90 Wildcards were not documented as returning sorted values, but the results
91 have been sorted up until this release.. If your makefiles require sorted
92 results from wildcard expansions, use the $(sort ...) function to request
95 * WARNING: Backward-incompatibility!
96 In previous versions of make it was acceptable to list one or more explicit
97 targets followed by one or more pattern targets in the same rule and it
98 worked "as expected". However, this was not documented as acceptable and if
99 you listed any explicit targets AFTER the pattern targets, the entire rule
100 would be mis-parsed. This release removes this ability completely: make
101 will generate an error message if you mix explicit and pattern targets in
104 * WARNING: Backward-incompatibility!
105 As a result of parser enhancements, three backward-compatibility issues
106 exist: first, a prerequisite containing an "=" cannot be escaped with a
107 backslash any longer. You must create a variable containing an "=" and
108 use that variable in the prerequisite. Second, variable names can no
109 longer contain whitespace, unless you put the whitespace in a variable and
110 use the variable. Third, in previous versions of make it was sometimes
111 not flagged as an error for explicit and pattern targets to appear in the
112 same rule. Now this is always reported as an error.
114 * WARNING: Backward-incompatibility!
115 The pattern-specific variables and pattern rules are now applied in the
116 shortest stem first order instead of the definition order (variables
117 and rules with the same stem length are still applied in the definition
118 order). This produces the usually-desired behavior where more specific
119 patterns are preferred. To detect this feature search for 'shortest-stem'
120 in the .FEATURES special variable.
122 * WARNING: Backward-incompatibility!
123 The library search behavior has changed to be compatible with the standard
124 linker behavior. Prior to this version for prerequisites specified using
125 the -lfoo syntax make first searched for libfoo.so in the current
126 directory, vpath directories, and system directories. If that didn't yield
127 a match, make then searched for libfoo.a in these directories. Starting
128 with this version make searches first for libfoo.so and then for libfoo.a
129 in each of these directories in order.
131 * New command line option: --eval=STRING causes STRING to be evaluated as
132 makefile syntax (akin to using the $(eval ...) function). The evaluation
133 is performed after all default rules and variables are defined, but before
134 any makefiles are read.
136 * New special variable: .RECIPEPREFIX allows you to reset the recipe
137 introduction character from the default (TAB) to something else. The
138 first character of this variable value is the new recipe introduction
139 character. If the variable is set to the empty string, TAB is used again.
140 It can be set and reset at will; recipes will use the value active when
141 they were first parsed. To detect this feature check the value of
144 * New special variable: .SHELLFLAGS allows you to change the options passed
145 to the shell when it invokes recipes. By default the value will be "-c"
146 (or "-ec" if .POSIX is set).
148 * New special target: .ONESHELL instructs make to invoke a single instance
149 of the shell and provide it with the entire recipe, regardless of how many
150 lines it contains. As a special feature to allow more straightforward
151 conversion of makefiles to use .ONESHELL, any recipe line control
152 characters ('@', '+', or '-') will be removed from the second and
153 subsequent recipe lines. This happens _only_ if the SHELL value is deemed
154 to be a standard POSIX-style shell. If not, then no interior line control
155 characters are removed (as they may be part of the scripting language used
156 with the alternate SHELL).
158 * New variable modifier 'private': prefixing a variable assignment with the
159 modifier 'private' suppresses inheritance of that variable by
160 prerequisites. This is most useful for target- and pattern-specific
163 * New make directive: 'undefine' allows you to undefine a variable so that
164 it appears as if it was never set. Both $(flavor) and $(origin) functions
165 will return 'undefined' for such a variable. To detect this feature search
166 for 'undefine' in the .FEATURES special variable.
168 * The parser for variable assignments has been enhanced to allow multiple
169 modifiers ('export', 'override', 'private') on the same line as variables,
170 including define/endef variables, and in any order. Also, it is possible
171 to create variables and targets named as these modifiers.
173 * The 'define' make directive now allows a variable assignment operator
174 after the variable name, to allow for simple, conditional, or appending
175 multi-line variable assignment.
180 * GNU make is ported to OS/2.
182 * GNU make is ported to MinGW. The MinGW build is only supported by
183 the build_w32.bat batch file; see the file README.W32 for more
186 * WARNING: Future backward-incompatibility!
187 Up to and including this release, the '$?' variable does not contain
188 any prerequisite that does not exist, even though that prerequisite
189 might have caused the target to rebuild. Starting with the _next_
190 release of GNU make, '$?' will contain all prerequisites that caused
191 the target to be considered out of date. See this Savannah bug:
192 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
194 * WARNING: Backward-incompatibility!
195 GNU make now implements a generic "second expansion" feature on the
196 prerequisites of both explicit and implicit (pattern) rules. In order
197 to enable this feature, the special target '.SECONDEXPANSION' must be
198 defined before the first target which takes advantage of it. If this
199 feature is enabled then after all rules have been parsed the
200 prerequisites are expanded again, this time with all the automatic
201 variables in scope. This means that in addition to using standard
202 SysV $$@ in prerequisites lists, you can also use complex functions
203 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
204 as well, where the second expansion occurs when the rule is matched.
205 However, this means that when '.SECONDEXPANSION' is enabled you must
206 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
207 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
208 which used to be available by default, is now ONLY available when the
209 .SECONDEXPANSION target is defined. If your makefiles take advantage
210 of this SysV feature you will need to update them.
212 * WARNING: Backward-incompatibility!
213 In order to comply with POSIX, the way in which GNU make processes
214 backslash-newline sequences in recipes has changed. If your makefiles
215 use backslash-newline sequences inside of single-quoted strings in
216 recipes you will be impacted by this change. See the GNU make manual
217 subsection "Splitting Recipe Lines" (node "Splitting Lines"), in
218 section "Recipe Syntax", chapter "Writing Recipe in Rules", for
221 * WARNING: Backward-incompatibility!
222 Some previous versions of GNU make had a bug where "#" in a function
223 invocation such as $(shell ...) was treated as a make comment. A
224 workaround was to escape these with backslashes. This bug has been
225 fixed: if your makefile uses "\#" in a function invocation the
226 backslash is now preserved, so you'll need to remove it.
228 * New command line option: -L (--check-symlink-times). On systems that
229 support symbolic links, if this option is given then GNU make will
230 use the most recent modification time of any symbolic links that are
231 used to resolve target files. The default behavior remains as it
232 always has: use the modification time of the actual target file only.
234 * The "else" conditional line can now be followed by any other valid
235 conditional on the same line: this does not increase the depth of the
236 conditional nesting, so only one "endif" is required to close the
239 * All pattern-specific variables that match a given target are now used
240 (previously only the first match was used).
242 * Target-specific variables can be marked as exportable using the
245 * In a recursive $(call ...) context, any extra arguments from the outer
246 call are now masked in the context of the inner call.
248 * Implemented a solution for the "thundering herd" problem with "-j -l".
249 This version of GNU make uses an algorithm suggested by Thomas Riedl
250 <thomas.riedl@siemens.com> to track the number of jobs started in the
251 last second and artificially adjust GNU make's view of the system's
252 load average accordingly.
254 * New special variables available in this release:
255 - .INCLUDE_DIRS: Expands to a list of directories that make searches
256 for included makefiles.
257 - .FEATURES: Contains a list of special features available in this
259 - .DEFAULT_GOAL: Set the name of the default goal make will
260 use if no goals are provided on the command line.
261 - MAKE_RESTARTS: If set, then this is the number of times this
262 instance of make has been restarted (see "How Makefiles Are Remade"
264 - New automatic variable: $| (added in 3.80, actually): contains all
265 the order-only prerequisites defined for the target.
267 * New functions available in this release:
268 - $(lastword ...) returns the last word in the list. This gives
269 identical results as $(word $(words ...) ...), but is much faster.
270 - $(abspath ...) returns the absolute path (all "." and ".."
271 directories resolved, and any duplicate "/" characters removed) for
273 - $(realpath ...) returns the canonical pathname for each path
274 provided. The canonical pathname is the absolute pathname, with
275 all symbolic links resolved as well.
276 - $(info ...) prints its arguments to stdout. No makefile name or
277 line number info, etc. is printed.
278 - $(flavor ...) returns the flavor of a variable.
279 - $(or ...) provides a short-circuiting OR conditional: each argument
280 is expanded. The first true (non-empty) argument is returned; no
281 further arguments are expanded. Expands to empty if there are no
283 - $(and ...) provides a short-circuiting AND conditional: each
284 argument is expanded. The first false (empty) argument is
285 returned; no further arguments are expanded. Expands to the last
286 argument if all arguments are true.
288 * Changes made for POSIX compatibility:
289 - Only touch targets (under -t) if they have a recipe.
290 - Setting the SHELL make variable does NOT change the value of the
291 SHELL environment variable given to programs invoked by make. As
292 an enhancement to POSIX, if you export the make variable SHELL then
293 it will be set in the environment, just as before.
295 * On MS Windows systems, explicitly setting SHELL to a pathname ending
296 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
297 the DOS command interpreter in batch mode even if a UNIX-like shell
298 could be found on the system.
300 * On VMS there is now support for case-sensitive filesystems such as ODS5.
301 See the readme.vms file for information.
303 * Parallel builds (-jN) no longer require a working Bourne shell on
304 Windows platforms. They work even with the stock Windows shells, such
305 as cmd.exe and command.com.
307 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
308 should not be impacted.
310 * New translations for Swedish, Chinese (simplified), Ukrainian,
311 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
314 A complete list of bugs fixed in this version is available here:
316 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
321 * A new feature exists: order-only prerequisites. These prerequisites
322 affect the order in which targets are built, but they do not impact
323 the rebuild/no-rebuild decision of their dependents. That is to say,
324 they allow you to require target B be built before target A, without
325 requiring that target A will always be rebuilt if target B is updated.
326 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
328 * For compatibility with SysV make, GNU make now supports the peculiar
329 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
330 This syntax is only valid within explicit and static pattern rules: it
331 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
332 <egp@free.fr> provided a patch implementing this feature; however, I
333 decided to implement it in a different way.
335 * The argument to the "ifdef" conditional is now expanded before it's
336 tested, so it can be a constructed variable name.
338 Similarly, the arguments to "export" (when not used in a variable
339 definition context) and "unexport" are also now expanded.
341 * A new function is defined: $(value ...). The argument to this
342 function is the _name_ of a variable. The result of the function is
343 the value of the variable, without having been expanded.
345 * A new function is defined: $(eval ...). The arguments to this
346 function should expand to makefile commands, which will then be
347 evaluated as if they had appeared in the makefile. In combination
348 with define/endef multiline variable definitions this is an extremely
349 powerful capability. The $(value ...) function is also sometimes
352 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
353 list of each makefile GNU make has read, or started to read, in the
354 order in which they were encountered. So, the last filename in the
355 list when a makefile is just being read (before any includes) is the
356 name of the current makefile.
358 * A new built-in variable is defined: $(.VARIABLES). When it is
359 expanded it returns a complete list of variable names defined by all
360 makefiles at that moment.
362 * A new command line option is defined, -B or --always-make. If
363 specified GNU make will consider all targets out-of-date even if they
364 would otherwise not be.
366 * The arguments to $(call ...) functions were being stored in $1, $2,
367 etc. as recursive variables, even though they are fully expanded
368 before assignment. This means that escaped dollar signs ($$ etc.)
369 were not behaving properly. Now the arguments are stored as simple
370 variables. This may mean that if you added extra escaping to your
371 $(call ...) function arguments you will need to undo it now.
373 * The variable invoked by $(call ...) can now be recursive: unlike other
374 variables it can reference itself and this will not produce an error
375 when it is used as the first argument to $(call ...) (but only then).
377 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
378 option --disable-nsec-timestamps. You might need this if your build
379 process depends on tools like "cp -p" preserving time stamps, since
380 "cp -p" (right now) doesn't preserve the subsecond portion of a time
383 * Updated translations for French, Galician, German, Japanese, Korean,
384 and Russian. New translations for Croatian, Danish, Hebrew, and
387 * Updated internationalization support to Gettext 0.11.5.
388 GNU make now uses Gettext's "external" feature, and does not include
389 any internationalization code itself. Configure will search your
390 system for an existing implementation of GNU Gettext (only GNU Gettext
391 is acceptable) and use it if it exists. If not, NLS will be disabled.
392 See ABOUT-NLS for more information.
394 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
396 A complete list of bugs fixed in this version is available here:
398 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
403 * .SECONDARY with no prerequisites now prevents any target from being
404 removed because make thinks it's an intermediate file, not just those
405 listed in the makefile.
407 * New configure option --disable-nsec-timestamps, but this was
408 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
412 * GNU make optionally supports internationalization and locales via the
413 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
414 file for more information on configuring GNU make for NLS.
416 * Previously, GNU make quoted variables such as MAKEFLAGS and
417 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
418 be used within make build scripts. However, using them there is not
419 proper behavior: they are meant to be passed to subshells via the
420 environment. Unfortunately the values were not quoted properly to be
421 passed through the environment. This meant that make didn't properly
422 pass some types of command line values to submakes.
424 With this version we change that behavior: now these variables are
425 quoted properly for passing through the environment, which is the
426 correct way to do it. If you previously used these variables
427 explicitly within a make rule you may need to re-examine your use for
428 correctness given this change.
430 * A new pseudo-target .NOTPARALLEL is available. If defined, the
431 current makefile is run serially regardless of the value of -j.
432 However, submakes are still eligible for parallel execution.
434 * The --debug option has changed: it now allows optional flags
435 controlling the amount and type of debugging output. By default only
436 a minimal amount information is generated, displaying the names of
437 "normal" targets (not makefiles) that were deemed out of date and in
438 need of being rebuilt.
440 Note that the -d option behaves as before: it takes no arguments and
441 all debugging information is generated.
443 * The `-p' (print database) output now includes filename and linenumber
444 information for variable definitions, to aid debugging.
446 * The wordlist function no longer reverses its arguments if the "start"
447 value is greater than the "end" value. If that's true, nothing is
450 * Hartmut Becker provided many updates for the VMS port of GNU make.
451 See the readme.vms file for more details.
455 * Two new functions, $(error ...) and $(warning ...) are available. The
456 former will cause make to fail and exit immediately upon expansion of
457 the function, with the text provided as the error message. The latter
458 causes the text provided to be printed as a warning message, but make
461 * A new function $(call ...) is available. This allows users to create
462 their own parameterized macros and invoke them later. Original
463 implementation of this function was provided by Han-Wen Nienhuys
466 * A new function $(if ...) is available. It provides if-then-else
467 capabilities in a builtin function. Original implementation of this
468 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
470 * Make defines a new variable, .LIBPATTERNS. This variable controls how
471 library dependency expansion (dependencies like ``-lfoo'') is performed.
473 * Make accepts CRLF sequences as well as traditional LF, for
474 compatibility with makefiles created on other operating systems.
476 * Make accepts a new option: -R, or --no-builtin-variables. This option
477 disables the definition of the rule-specific builtin variables (CC,
478 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
481 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
483 On systems that support POSIX pipe(2) semantics, GNU make can now pass
484 -jN options to submakes rather than forcing them all to use -j1. The
485 top make and all its sub-make processes use a pipe to communicate with
486 each other to ensure that no more than N jobs are started across all
487 makes. To get the old behavior of -j back, you can configure make
488 with the --disable-job-server option.
490 * The confusing term "dependency" has been replaced by the more accurate
491 and standard term "prerequisite", both in the manual and in all GNU make
494 * GNU make supports the "big archive" library format introduced in AIX 4.3.
496 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
497 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
498 support for Solaris and Linux was introduced in 3.77, but the
499 configuration had issues: these have also been resolved).
501 * The Windows 95/98/NT (W32) version of GNU make now has native support
502 for the Cygnus Cygwin release B20.1 shell (bash).
504 * The GNU make regression test suite, long available separately "under
505 the table", has been integrated into the release. You can invoke it
506 by running "make check" in the distribution. Note that it requires
507 Perl (either Perl 4 or Perl 5) to run.
511 * Implement BSD make's "?=" variable assignment operator. The variable
512 is assigned the specified value only if that variable is not already
515 * Make defines a new variable, "CURDIR", to contain the current working
516 directory (after the -C option, if any, has been processed).
517 Modifying this variable has no effect on the operation of make.
519 * Make defines a new default RCS rule, for new-style master file
520 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
522 Make defines new default rules for DOS-style C++ file naming
523 conventions, with ``.cpp'' suffixes. All the same rules as for
524 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
525 COMPILE.cpp macros (which default to the same value as LINK.cc and
526 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
527 use CXXFLAGS to change C++ compiler flags.
529 * A new feature, "target-specific variable values", has been added.
530 This is a large change so please see the appropriate sections of the
531 manual for full details. Briefly, syntax like this:
533 TARGET: VARIABLE = VALUE
535 defines VARIABLE as VALUE within the context of TARGET. This is
536 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
537 that the assignment may be of any type, not just recursive, and that
538 the override keyword is available.
540 COMPATIBILITY: This new syntax means that if you have any rules where
541 the first or second dependency has an equal sign (=) in its name,
542 you'll have to escape them with a backslash: "foo : bar\=baz".
543 Further, if you have any dependencies which already contain "\=",
544 you'll have to escape both of them: "foo : bar\\\=baz".
546 * A new appendix listing the most common error and warning messages
547 generated by GNU make, with some explanation, has been added to the
548 GNU make User's Manual.
550 * Updates to the GNU make Customs library support (see README.customs).
552 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
553 and to the DOS port from Eli Zaretski (see README.DOS).
557 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
561 * GNU make now uses automake to control Makefile.in generation. This
562 should make it more consistent with the GNU standards.
564 * VPATH functionality has been changed to incorporate the VPATH+ patch,
565 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
568 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
569 were specified on the command line, if any. Modifying this variable
570 has no effect on the operation of make.
572 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
573 list of words from number S to number E (inclusive) of TEXT.
575 * Instead of an error, detection of future modification times gives a
576 warning and continues. The warning is repeated just before GNU make
577 exits, so it is less likely to be lost.
579 * Fix the $(basename) and $(suffix) functions so they only operate on
580 the last filename, not the entire string:
582 Command Old Result New Result
583 ------- ---------- ----------
585 $(basename a.b/c) a a.b/c
587 $(suffix a.b/c) b/c <empty>
589 * The $(strip) function now removes newlines as well as TABs and spaces.
591 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
594 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
596 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
597 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
598 and utilities. See README.DOS for details, and direct all questions
599 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
600 Delorie <dj@delorie.com>.
602 * John W. Eaton has updated the VMS port to support libraries and VPATH.
606 * The directory messages printed by `-w' and implicitly in sub-makes,
607 are now omitted if Make runs no commands and has no other messages to print.
609 * Make now detects files that for whatever reason have modification times
610 in the future and gives an error. Files with such impossible timestamps
611 can result from unsynchronized clocks, or archived distributions
612 containing bogus timestamps; they confuse Make's dependency engine
615 * The new directive `sinclude' is now recognized as another name for
616 `-include', for compatibility with some other Makes.
618 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
619 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
621 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
622 See README.W32 for details, and direct all Windows-related questions to
623 <rob_tulloh@tivoli.com>.
627 * Converted to use Autoconf version 2, so `configure' has some new options.
628 See INSTALL for details.
630 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
631 output enabled by -d, at any time during the run.
635 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
636 He is maintaining the DOS port, not the GNU Make maintainer;
637 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
638 MS-DOS binaries are available for FTP from ftp.simtel.net in
639 /pub/simtelnet/gnu/djgpp/.
641 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
642 contain variable definitions itself; these are treated just like
643 command line variable definitions. Make will automatically insert any
644 variable definitions from the environment value of `MAKEFLAGS' or from
645 the command line, into the `MAKEFLAGS' value exported to children. The
646 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
647 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
648 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
649 in the environment when its size is limited.
651 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
652 a rule if it has changed when its recipe exits with a nonzero status,
653 just as when the recipe gets a signal.
655 * The automatic variable `$+' is new. It lists all the dependencies like
656 `$^', but preserves duplicates listed in the makefile. This is useful
657 for linking rules, where library files sometimes need to be listed twice
660 * You can now specify the `.IGNORE' and `.SILENT' special targets with
661 dependencies to limit their effects to those files. If a file appears as
662 a dependency of `.IGNORE', then errors will be ignored while running the
663 recipe to update that file. Likewise if a file appears as a dependency
664 of `.SILENT', then the recipe to update that file will not be printed
665 before it is run. (This change was made to conform to POSIX.2.)
669 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
670 `$(^D)' now omit the trailing slash from the directory name. (This change
671 was made to comply with POSIX.2.)
673 * The source distribution now includes the Info files for the Make manual.
674 There is no longer a separate distribution containing Info and DVI files.
676 * You can now set the variables `binprefix' and/or `manprefix' in
677 Makefile.in (or on the command line when installing) to install GNU make
678 under a name other than `make' (i.e., ``make binprefix=g install''
679 installs GNU make as `gmake').
681 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
682 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
685 * The exit status of Make when it runs into errors is now 2 instead of 1.
686 The exit status is 1 only when using -q and some target is not up to date.
687 (This change was made to comply with POSIX.2.)
691 * It is no longer a fatal error to have a NUL character in a makefile.
692 You should never put a NUL in a makefile because it can have strange
693 results, but otherwise empty lines full of NULs (such as produced by
694 the `xmkmf' program) will always work fine.
696 * The error messages for nonexistent included makefiles now refer to the
697 makefile name and line number where the `include' appeared, so Emacs's
698 C-x ` command takes you there (in case it's a typo you need to fix).
702 * Implicit rule search for archive member references is now done in the
703 opposite order from previous versions: the whole target name `LIB(MEM)'
704 first, and just the member name and parentheses `(MEM)' second.
706 * Make now gives an error for an unterminated variable or function reference.
707 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
709 * The new default variable `MAKE_VERSION' gives the version number of
710 Make, and a string describing the remote job support compiled in (if any).
711 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
713 * Commands in an invocation of the `shell' function are no longer run
714 with a modified environment like recipes are. As in versions before
715 3.68, they now run with the environment that `make' started with. We
716 have reversed the change made in version 3.68 because it turned out to
717 cause a paradoxical situation in cases like:
719 export variable = $(shell echo value)
721 When Make attempted to put this variable in the environment for a
722 recipe, it would try expand the value by running the shell command
723 `echo value'. In version 3.68, because it constructed an environment
724 for that shell command in the same way, Make would begin to go into an
725 infinite loop and then get a fatal error when it detected the loop.
727 * The recipe given for `.DEFAULT' is now used for phony targets with no
732 * You can list several archive member names inside parenthesis:
733 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
735 * You can use wildcards inside archive member references. For example,
736 `lib(*.o)' expands to all existing members of `lib' whose names end in
737 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
738 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
739 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
741 * A suffix rule `.X.a' now produces two pattern rules:
742 (%.o): %.X # Previous versions produced only this.
743 %.a: %.X # Now produces this as well, just like other suffixes.
745 * The new flag `--warn-undefined-variables' says to issue a warning message
746 whenever Make expands a reference to an undefined variable.
748 * The new `-include' directive is just like `include' except that there is
749 no error (not even a warning) for a nonexistent makefile.
751 * Commands in an invocation of the `shell' function are now run with a
752 modified environment like recipes are, so you can use `export' et al
753 to set up variables for them. They used to run with the environment
754 that `make' started with.
758 * `make --version' (or `make -v') now exits immediately after printing
763 * Make now supports long-named members in `ar' archive files.
767 * Make now supports the `+=' syntax for a variable definition which appends
768 to the variable's previous value. See the section `Appending More Text
769 to Variables' in the manual for full details.
771 * The new option `--no-print-directory' inhibits the `-w' or
772 `--print-directory' feature. Make turns on `--print-directory'
773 automatically if you use `-C' or `--directory', and in sub-makes; some
774 users have found this behavior undesirable.
776 * The built-in implicit rules now support the alternative extension
777 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
781 * Make now uses a standard GNU `configure' script. See the new file
782 INSTALL for the new (and much simpler) installation procedure.
784 * There is now a shell script to build Make the first time, if you have no
785 other `make' program. `build.sh' is created by `configure'; see README.
787 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
789 * Elements of the `$^' and `$?' automatic variables that are archive
790 member references now list only the member name, as in Unix and POSIX.2.
792 * You should no longer ever need to specify the `-w' switch, which prints
793 the current directory before and after Make runs. The `-C' switch to
794 change directory, and recursive use of Make, now set `-w' automatically.
796 * Multiple double-colon rules for the same target will no longer have their
797 recipes run simultaneously under -j, as this could result in the two
798 recipes trying to change the file at the same time and interfering with
801 * The `SHELL' variable is now never taken from the environment.
802 Each makefile that wants a shell other than the default (/bin/sh) must
803 set SHELL itself. SHELL is always exported to child processes.
804 This change was made for compatibility with POSIX.2.
806 * Make now accepts long options. There is now an informative usage message
807 that tells you what all the options are and what they do. Try `make --help'.
809 * There are two new directives: `export' and `unexport'. All variables are
810 no longer automatically put into the environments of the recipe lines that
811 Make runs. Instead, only variables specified on the command line or in
812 the environment are exported by default. To export others, use:
814 or you can define variables with:
815 export VARIABLE = VALUE
817 export VARIABLE := VALUE
821 .EXPORT_ALL_VARIABLES:
822 to get the old behavior. See the node `Variables/Recursion' in the manual
823 for a full description.
825 * The recipe from the `.DEFAULT' special target is only applied to
826 targets which have no rules at all, not all targets with no recipe.
827 This change was made for compatibility with Unix make.
829 * All fatal error messages now contain `***', so they are easy to find in
832 * Dependency file names like `-lNAME' are now replaced with the actual file
833 name found, as with files found by normal directory search (VPATH).
834 The library file `libNAME.a' may now be found in the current directory,
835 which is checked before VPATH; the standard set of directories (/lib,
836 /usr/lib, /usr/local/lib) is now checked last.
837 See the node `Libraries/Search' in the manual for full details.
839 * A single `include' directive can now specify more than one makefile to
842 You can also use shell file name patterns in an `include' directive:
845 * The default directories to search for included makefiles, and for
846 libraries specified with `-lNAME', are now set by configuration.
848 * You can now use blanks as well as colons to separate the directories in a
849 search path for the `vpath' directive or the `VPATH' variable.
851 * You can now use variables and functions in the left hand side of a
852 variable assignment, as in "$(foo)bar = value".
854 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
855 The `MAKE_COMMAND' variable is now defined to the name with which make
858 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
859 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
860 problems with shells that cannot have `+' in environment variable names.
862 * The value of a recursively expanded variable is now expanded when putting
863 it into the environment for child processes. This change was made for
864 compatibility with Unix make.
866 * A rule with no targets before the `:' is now accepted and ignored.
867 This change was made for compatibility with SunOS 4 make.
868 We do not recommend that you write your makefiles to take advantage of this.
870 * The `-I' switch can now be used in MAKEFLAGS, and are put there
871 automatically just like other switches.
875 * Built-in rules for C++ source files with the `.C' suffix.
876 We still recommend that you use `.cc' instead.
878 * If a recipe is given too many times for a single target, the last one
879 given is used, and a warning message is printed.
881 * Error messages about makefiles are in standard GNU error format,
882 so C-x ` in Emacs works on them.
884 * Dependencies of pattern rules which contain no % need not actually exist
885 if they can be created (just like dependencies which do have a %).
889 * A message is always printed when Make decides there is nothing to be done.
890 It used to be that no message was printed for top-level phony targets
891 (because "`phony' is up to date" isn't quite right). Now a different
892 message "Nothing to be done for `phony'" is printed in that case.
894 * Archives on AIX now supposedly work.
896 * When the recipes specified for .DEFAULT are used to update a target,
897 the $< automatic variable is given the same value as $@ for that target.
898 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
902 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
903 variables while remaking makefiles, so recursive makes done while remaking
904 makefiles will behave properly.
906 * If the special target `.NOEXPORT' is specified in a makefile,
907 only variables that came from the environment and variables
908 defined on the command line are exported.
912 * Suffix rules may have dependencies (which are ignored).
916 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
917 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
921 * There is now a Unix man page for GNU Make. It is certainly not a
922 replacement for the Texinfo manual, but it documents the basic
923 functionality and the switches. For full documentation, you should
924 still read the Texinfo manual. Thanks to Dennis Morse of Stanford
925 University for contributing the initial version of this.
927 * Variables which are defined by default (e.g., `CC') will no longer be
928 put into the environment for child processes. (If these variables are
929 reset by the environment, makefiles, or the command line, they will
930 still go into the environment.)
932 * Makefiles which have recipes but no dependencies (and thus are always
933 considered out of date and in need of remaking), will not be remade (if they
934 were being remade only because they were makefiles). This means that GNU
935 Make will no longer go into an infinite loop when fed the makefiles that
936 `imake' (necessary to build X Windows) produces.
938 * There is no longer a warning for using the `vpath' directive with an explicit
939 pathname (instead of a `%' pattern).
943 * When removing intermediate files, only one `rm' command line is printed,
944 listing all file names.
946 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
947 These are the directory-only and file-only versions of `$^' and `$?'.
949 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
950 directory if it exists.
952 * The automatic variable `$($/)' is no longer defined.
954 * Leading `+' characters on a recipe line make that line be executed even
955 under -n, -t, or -q (as if the line contained `$(MAKE)').
957 * For recipe lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
958 only those lines are executed, not the entire recipe.
959 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
963 * Filenames in rules will now have ~ and ~USER expanded.
965 * The `-p' output has been changed so it can be used as a makefile.
966 (All information that isn't specified by makefiles is prefaced with comment
971 * The % character can be quoted with backslash in implicit pattern rules,
972 static pattern rules, `vpath' directives, and `patsubst', `filter', and
973 `filter-out' functions. A warning is issued if a `vpath' directive's
974 pattern contains no %.
976 * The `wildcard' variable expansion function now expands ~ and ~USER.
978 * Messages indicating failed recipe lines now contain the target name:
979 make: *** [target] Error 1
981 * The `-p' output format has been changed somewhat to look more like
982 makefile rules and to give all information that Make has about files.
988 * The `-l' switch with no argument removes any previous load-average limit.
990 * When the `-w' switch is in effect, and Make has updated makefiles,
991 it will write a `Leaving directory' message before re-executing itself.
992 This makes the `directory change tracking' changes to Emacs's compilation
993 commands work properly.
997 * The automatic variable `$*' is now defined for explicit rules,
998 as it is in Unix make.
1002 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
1003 specified without an argument (indicating infinite jobs).
1004 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
1006 * Make no longer checks hashed directories after running recipes.
1007 The behavior implemented in 3.41 caused too much slowdown.
1011 * A dependency is NOT considered newer than its dependent if
1012 they have the same modification time. The behavior implemented
1013 in 3.43 conflicts with RCS.
1017 * Dependency loops are no longer fatal errors.
1019 * A dependency is considered newer than its dependent if
1020 they have the same modification time.
1024 * The variables F77 and F77FLAGS are now set by default to $(FC) and
1025 $(FFLAGS). Makefiles designed for System V make may use these variables in
1026 explicit rules and expect them to be set. Unfortunately, there is no way to
1027 make setting these affect the Fortran implicit rules unless FC and FFLAGS
1028 are not used (and these are used by BSD make).
1032 * Make now checks to see if its hashed directories are changed by recipes.
1033 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
1037 * The `shell' function no longer captures standard error output.
1041 * A file beginning with a dot can be the default target if it also contains
1042 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
1046 * Archive member names are truncated to 15 characters.
1048 * Yet more USG stuff.
1050 * Minimal support for Microport System V (a 16-bit machine and a
1051 brain-damaged compiler). This has even lower priority than other USG
1052 support, so if it gets beyond trivial, I will take it out completely.
1054 * Revamped default implicit rules (not much visible change).
1056 * The -d and -p options can come from the environment.
1060 * Improved support for USG and HPUX (hopefully).
1062 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
1063 equivalent to `$(patsubst a,b,$(foo))'.
1065 * Defining .DEFAULT with no deps or recipe clears its recipe.
1067 * New default implicit rules for .S (cpp, then as), and .sh (copy and
1068 make executable). All default implicit rules that use cpp (even
1069 indirectly), use $(CPPFLAGS).
1073 * Giving the -j option with no arguments gives you infinite jobs.
1077 * New option: "-l LOAD" says not to start any new jobs while others are
1078 running if the load average is not below LOAD (a floating-point number).
1080 * There is support in place for implementations of remote command execution
1081 in Make. See the file remote.c.
1085 * No more than 10 directories will be kept open at once.
1086 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
1090 * Archive files will have their modification times recorded before doing
1091 anything that might change their modification times by updating an archive
1096 * The `MAKELEVEL' variable is defined for use by makefiles.
1100 * The recursion level indications in error messages are much shorter than
1101 they were in version 3.14.
1105 * Leading spaces before directives are ignored (as documented).
1107 * Included makefiles can determine the default goal target.
1108 (System V Make does it this way, so we are being compatible).
1112 * Variables that are defaults built into Make will not be put in the
1113 environment for children. This just saves some environment space and,
1114 except under -e, will be transparent to sub-makes.
1116 * Error messages from sub-makes will indicate the level of recursion.
1118 * Hopefully some speed-up for large directories due to a change in the
1119 directory hashing scheme.
1121 * One child will always get a standard input that is usable.
1123 * Default makefiles that don't exist will be remade and read in.
1127 * Count parentheses inside expansion function calls so you can
1128 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
1132 * Several bug fixes, including USG and Sun386i support.
1134 * `shell' function to expand shell commands a la `
1136 * If the `-d' flag is given, version information will be printed.
1138 * The `-c' option has been renamed to `-C' for compatibility with tar.
1140 * The `-p' option no longer inhibits other normal operation.
1142 * Makefiles will be updated and re-read if necessary.
1144 * Can now run several recipes at once (parallelism), -j option.
1146 * Error messages will contain the level of Make recursion, if any.
1148 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
1151 * A double-colon rule with no dependencies will always have its recipe run.
1152 (This is how both the BSD and System V versions of Make do it.)
1156 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
1158 -------------------------------------------------------------------------------
1159 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1160 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
1161 2012 Free Software Foundation, Inc.
1162 This file is part of GNU Make.
1164 GNU Make is free software; you can redistribute it and/or modify it under the
1165 terms of the GNU General Public License as published by the Free Software
1166 Foundation; either version 3 of the License, or (at your option) any later
1169 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1170 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1171 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1173 You should have received a copy of the GNU General Public License along with
1174 this program. If not, see <http://www.gnu.org/licenses/>.