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 This version of make adheres to the POSIX backslash/newline handling,
20 introducing the following differences:
21 * Each backslash/newline in a variable value is replaced with a space;
22 multiple consecutive backslash/newlines do not condense into one space.
23 * In recipes, a recipe prefix following a backslash-newlines is removed.
25 * New feature: "!=" shell assignment operator as an alternative to the
26 $(shell ...) function. Implemented for portability of BSD makefiles.
27 WARNING: Backward-incompatibility!
28 Variables ending in "!" previously defined as "variable!= value" will now be
29 interpreted as shell assignment. Change your assignment to add whitespace
30 between the "!" and "=": "variable! = value"
32 * New command line option: --trace enables tracing of targets. When enabled
33 the recipe to be invoked is printed even if it would otherwise be suppressed
34 by .SILENT or a "@" prefix character. Also before each recipe is run the
35 makefile name and linenumber where it was defined are shown as well as the
36 prerequisites that caused the target to be considered out of date.
38 * On failure, the makefile name and linenumber of the recipe that failed are
41 * A .RECIPEPREFIX setting is remembered per-recipe and variables expanded
42 in that recipe also use that recipe prefix setting.
44 * In -p output, .RECIPEPREFIX settings are shown and all target-specific
45 variables are output as if in a makefile, instead of as comments.
50 A complete list of bugs fixed in this version is available here:
52 http://sv.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=104&set=custom
54 * Compiling GNU make now requires a conforming ISO C 1989 compiler and
55 standard runtime library.
57 * WARNING: Backward-incompatibility!
58 The POSIX standard for make was changed in the 2008 version in a
59 fundamentally incompatible way: make is required to invoke the shell as if
60 the '-e' flag were provided. Because this would break many makefiles that
61 have been written to conform to the original text of the standard, the
62 default behavior of GNU make remains to invoke the shell with simply '-c'.
63 However, any makefile specifying the .POSIX special target will follow the
64 new POSIX standard and pass '-e' to the shell. See also .SHELLFLAGS
67 * WARNING: Backward-incompatibility!
68 The '$?' variable now contains all prerequisites that caused the target to
69 be considered out of date, even if they do not exist (previously only
70 existing targets were provided in $?).
72 * WARNING: Backward-incompatibility!
73 Wildcards were not documented as returning sorted values, but the results
74 have been sorted up until this release.. If your makefiles require sorted
75 results from wildcard expansions, use the $(sort ...) function to request
78 * WARNING: Backward-incompatibility!
79 In previous versions of make it was acceptable to list one or more explicit
80 targets followed by one or more pattern targets in the same rule and it
81 worked "as expected". However, this was not documented as acceptable and if
82 you listed any explicit targets AFTER the pattern targets, the entire rule
83 would be mis-parsed. This release removes this ability completely: make
84 will generate an error message if you mix explicit and pattern targets in
87 * WARNING: Backward-incompatibility!
88 As a result of parser enhancements, three backward-compatibility issues
89 exist: first, a prerequisite containing an "=" cannot be escaped with a
90 backslash any longer. You must create a variable containing an "=" and
91 use that variable in the prerequisite. Second, variable names can no
92 longer contain whitespace, unless you put the whitespace in a variable and
93 use the variable. Third, in previous versions of make it was sometimes
94 not flagged as an error for explicit and pattern targets to appear in the
95 same rule. Now this is always reported as an error.
97 * WARNING: Backward-incompatibility!
98 The pattern-specific variables and pattern rules are now applied in the
99 shortest stem first order instead of the definition order (variables
100 and rules with the same stem length are still applied in the definition
101 order). This produces the usually-desired behavior where more specific
102 patterns are preferred. To detect this feature search for 'shortest-stem'
103 in the .FEATURES special variable.
105 * WARNING: Backward-incompatibility!
106 The library search behavior has changed to be compatible with the standard
107 linker behavior. Prior to this version for prerequisites specified using
108 the -lfoo syntax make first searched for libfoo.so in the current
109 directory, vpath directories, and system directories. If that didn't yield
110 a match, make then searched for libfoo.a in these directories. Starting
111 with this version make searches first for libfoo.so and then for libfoo.a
112 in each of these directories in order.
114 * New command line option: --eval=STRING causes STRING to be evaluated as
115 makefile syntax (akin to using the $(eval ...) function). The evaluation
116 is performed after all default rules and variables are defined, but before
117 any makefiles are read.
119 * New special variable: .RECIPEPREFIX allows you to reset the recipe
120 introduction character from the default (TAB) to something else. The
121 first character of this variable value is the new recipe introduction
122 character. If the variable is set to the empty string, TAB is used again.
123 It can be set and reset at will; recipes will use the value active when
124 they were first parsed. To detect this feature check the value of
127 * New special variable: .SHELLFLAGS allows you to change the options passed
128 to the shell when it invokes recipes. By default the value will be "-c"
129 (or "-ec" if .POSIX is set).
131 * New special target: .ONESHELL instructs make to invoke a single instance
132 of the shell and provide it with the entire recipe, regardless of how many
133 lines it contains. As a special feature to allow more straightforward
134 conversion of makefiles to use .ONESHELL, any recipe line control
135 characters ('@', '+', or '-') will be removed from the second and
136 subsequent recipe lines. This happens _only_ if the SHELL value is deemed
137 to be a standard POSIX-style shell. If not, then no interior line control
138 characters are removed (as they may be part of the scripting language used
139 with the alternate SHELL).
141 * New variable modifier 'private': prefixing a variable assignment with the
142 modifier 'private' suppresses inheritance of that variable by
143 prerequisites. This is most useful for target- and pattern-specific
146 * New make directive: 'undefine' allows you to undefine a variable so that
147 it appears as if it was never set. Both $(flavor) and $(origin) functions
148 will return 'undefined' for such a variable. To detect this feature search
149 for 'undefine' in the .FEATURES special variable.
151 * The parser for variable assignments has been enhanced to allow multiple
152 modifiers ('export', 'override', 'private') on the same line as variables,
153 including define/endef variables, and in any order. Also, it is possible
154 to create variables and targets named as these modifiers.
156 * The 'define' make directive now allows a variable assignment operator
157 after the variable name, to allow for simple, conditional, or appending
158 multi-line variable assignment.
163 * GNU make is ported to OS/2.
165 * GNU make is ported to MinGW. The MinGW build is only supported by
166 the build_w32.bat batch file; see the file README.W32 for more
169 * WARNING: Future backward-incompatibility!
170 Up to and including this release, the '$?' variable does not contain
171 any prerequisite that does not exist, even though that prerequisite
172 might have caused the target to rebuild. Starting with the _next_
173 release of GNU make, '$?' will contain all prerequisites that caused
174 the target to be considered out of date. See this Savannah bug:
175 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
177 * WARNING: Backward-incompatibility!
178 GNU make now implements a generic "second expansion" feature on the
179 prerequisites of both explicit and implicit (pattern) rules. In order
180 to enable this feature, the special target '.SECONDEXPANSION' must be
181 defined before the first target which takes advantage of it. If this
182 feature is enabled then after all rules have been parsed the
183 prerequisites are expanded again, this time with all the automatic
184 variables in scope. This means that in addition to using standard
185 SysV $$@ in prerequisites lists, you can also use complex functions
186 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
187 as well, where the second expansion occurs when the rule is matched.
188 However, this means that when '.SECONDEXPANSION' is enabled you must
189 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
190 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
191 which used to be available by default, is now ONLY available when the
192 .SECONDEXPANSION target is defined. If your makefiles take advantage
193 of this SysV feature you will need to update them.
195 * WARNING: Backward-incompatibility!
196 In order to comply with POSIX, the way in which GNU make processes
197 backslash-newline sequences in recipes has changed. If your makefiles
198 use backslash-newline sequences inside of single-quoted strings in
199 recipes you will be impacted by this change. See the GNU make manual
200 subsection "Splitting Recipe Lines" (node "Splitting Lines"), in
201 section "Recipe Syntax", chapter "Writing Recipe in Rules", for
204 * WARNING: Backward-incompatibility!
205 Some previous versions of GNU make had a bug where "#" in a function
206 invocation such as $(shell ...) was treated as a make comment. A
207 workaround was to escape these with backslashes. This bug has been
208 fixed: if your makefile uses "\#" in a function invocation the
209 backslash is now preserved, so you'll need to remove it.
211 * New command line option: -L (--check-symlink-times). On systems that
212 support symbolic links, if this option is given then GNU make will
213 use the most recent modification time of any symbolic links that are
214 used to resolve target files. The default behavior remains as it
215 always has: use the modification time of the actual target file only.
217 * The "else" conditional line can now be followed by any other valid
218 conditional on the same line: this does not increase the depth of the
219 conditional nesting, so only one "endif" is required to close the
222 * All pattern-specific variables that match a given target are now used
223 (previously only the first match was used).
225 * Target-specific variables can be marked as exportable using the
228 * In a recursive $(call ...) context, any extra arguments from the outer
229 call are now masked in the context of the inner call.
231 * Implemented a solution for the "thundering herd" problem with "-j -l".
232 This version of GNU make uses an algorithm suggested by Thomas Riedl
233 <thomas.riedl@siemens.com> to track the number of jobs started in the
234 last second and artificially adjust GNU make's view of the system's
235 load average accordingly.
237 * New special variables available in this release:
238 - .INCLUDE_DIRS: Expands to a list of directories that make searches
239 for included makefiles.
240 - .FEATURES: Contains a list of special features available in this
242 - .DEFAULT_GOAL: Set the name of the default goal make will
243 use if no goals are provided on the command line.
244 - MAKE_RESTARTS: If set, then this is the number of times this
245 instance of make has been restarted (see "How Makefiles Are Remade"
247 - New automatic variable: $| (added in 3.80, actually): contains all
248 the order-only prerequisites defined for the target.
250 * New functions available in this release:
251 - $(lastword ...) returns the last word in the list. This gives
252 identical results as $(word $(words ...) ...), but is much faster.
253 - $(abspath ...) returns the absolute path (all "." and ".."
254 directories resolved, and any duplicate "/" characters removed) for
256 - $(realpath ...) returns the canonical pathname for each path
257 provided. The canonical pathname is the absolute pathname, with
258 all symbolic links resolved as well.
259 - $(info ...) prints its arguments to stdout. No makefile name or
260 line number info, etc. is printed.
261 - $(flavor ...) returns the flavor of a variable.
262 - $(or ...) provides a short-circuiting OR conditional: each argument
263 is expanded. The first true (non-empty) argument is returned; no
264 further arguments are expanded. Expands to empty if there are no
266 - $(and ...) provides a short-circuiting AND conditional: each
267 argument is expanded. The first false (empty) argument is
268 returned; no further arguments are expanded. Expands to the last
269 argument if all arguments are true.
271 * Changes made for POSIX compatibility:
272 - Only touch targets (under -t) if they have a recipe.
273 - Setting the SHELL make variable does NOT change the value of the
274 SHELL environment variable given to programs invoked by make. As
275 an enhancement to POSIX, if you export the make variable SHELL then
276 it will be set in the environment, just as before.
278 * On MS Windows systems, explicitly setting SHELL to a pathname ending
279 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
280 the DOS command interpreter in batch mode even if a UNIX-like shell
281 could be found on the system.
283 * On VMS there is now support for case-sensitive filesystems such as ODS5.
284 See the readme.vms file for information.
286 * Parallel builds (-jN) no longer require a working Bourne shell on
287 Windows platforms. They work even with the stock Windows shells, such
288 as cmd.exe and command.com.
290 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
291 should not be impacted.
293 * New translations for Swedish, Chinese (simplified), Ukrainian,
294 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
297 A complete list of bugs fixed in this version is available here:
299 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
304 * A new feature exists: order-only prerequisites. These prerequisites
305 affect the order in which targets are built, but they do not impact
306 the rebuild/no-rebuild decision of their dependents. That is to say,
307 they allow you to require target B be built before target A, without
308 requiring that target A will always be rebuilt if target B is updated.
309 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
311 * For compatibility with SysV make, GNU make now supports the peculiar
312 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
313 This syntax is only valid within explicit and static pattern rules: it
314 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
315 <egp@free.fr> provided a patch implementing this feature; however, I
316 decided to implement it in a different way.
318 * The argument to the "ifdef" conditional is now expanded before it's
319 tested, so it can be a constructed variable name.
321 Similarly, the arguments to "export" (when not used in a variable
322 definition context) and "unexport" are also now expanded.
324 * A new function is defined: $(value ...). The argument to this
325 function is the _name_ of a variable. The result of the function is
326 the value of the variable, without having been expanded.
328 * A new function is defined: $(eval ...). The arguments to this
329 function should expand to makefile commands, which will then be
330 evaluated as if they had appeared in the makefile. In combination
331 with define/endef multiline variable definitions this is an extremely
332 powerful capability. The $(value ...) function is also sometimes
335 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
336 list of each makefile GNU make has read, or started to read, in the
337 order in which they were encountered. So, the last filename in the
338 list when a makefile is just being read (before any includes) is the
339 name of the current makefile.
341 * A new built-in variable is defined: $(.VARIABLES). When it is
342 expanded it returns a complete list of variable names defined by all
343 makefiles at that moment.
345 * A new command line option is defined, -B or --always-make. If
346 specified GNU make will consider all targets out-of-date even if they
347 would otherwise not be.
349 * The arguments to $(call ...) functions were being stored in $1, $2,
350 etc. as recursive variables, even though they are fully expanded
351 before assignment. This means that escaped dollar signs ($$ etc.)
352 were not behaving properly. Now the arguments are stored as simple
353 variables. This may mean that if you added extra escaping to your
354 $(call ...) function arguments you will need to undo it now.
356 * The variable invoked by $(call ...) can now be recursive: unlike other
357 variables it can reference itself and this will not produce an error
358 when it is used as the first argument to $(call ...) (but only then).
360 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
361 option --disable-nsec-timestamps. You might need this if your build
362 process depends on tools like "cp -p" preserving time stamps, since
363 "cp -p" (right now) doesn't preserve the subsecond portion of a time
366 * Updated translations for French, Galician, German, Japanese, Korean,
367 and Russian. New translations for Croatian, Danish, Hebrew, and
370 * Updated internationalization support to Gettext 0.11.5.
371 GNU make now uses Gettext's "external" feature, and does not include
372 any internationalization code itself. Configure will search your
373 system for an existing implementation of GNU Gettext (only GNU Gettext
374 is acceptable) and use it if it exists. If not, NLS will be disabled.
375 See ABOUT-NLS for more information.
377 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
379 A complete list of bugs fixed in this version is available here:
381 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
386 * .SECONDARY with no prerequisites now prevents any target from being
387 removed because make thinks it's an intermediate file, not just those
388 listed in the makefile.
390 * New configure option --disable-nsec-timestamps, but this was
391 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
395 * GNU make optionally supports internationalization and locales via the
396 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
397 file for more information on configuring GNU make for NLS.
399 * Previously, GNU make quoted variables such as MAKEFLAGS and
400 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
401 be used within make build scripts. However, using them there is not
402 proper behavior: they are meant to be passed to subshells via the
403 environment. Unfortunately the values were not quoted properly to be
404 passed through the environment. This meant that make didn't properly
405 pass some types of command line values to submakes.
407 With this version we change that behavior: now these variables are
408 quoted properly for passing through the environment, which is the
409 correct way to do it. If you previously used these variables
410 explicitly within a make rule you may need to re-examine your use for
411 correctness given this change.
413 * A new pseudo-target .NOTPARALLEL is available. If defined, the
414 current makefile is run serially regardless of the value of -j.
415 However, submakes are still eligible for parallel execution.
417 * The --debug option has changed: it now allows optional flags
418 controlling the amount and type of debugging output. By default only
419 a minimal amount information is generated, displaying the names of
420 "normal" targets (not makefiles) that were deemed out of date and in
421 need of being rebuilt.
423 Note that the -d option behaves as before: it takes no arguments and
424 all debugging information is generated.
426 * The `-p' (print database) output now includes filename and linenumber
427 information for variable definitions, to aid debugging.
429 * The wordlist function no longer reverses its arguments if the "start"
430 value is greater than the "end" value. If that's true, nothing is
433 * Hartmut Becker provided many updates for the VMS port of GNU make.
434 See the readme.vms file for more details.
438 * Two new functions, $(error ...) and $(warning ...) are available. The
439 former will cause make to fail and exit immediately upon expansion of
440 the function, with the text provided as the error message. The latter
441 causes the text provided to be printed as a warning message, but make
444 * A new function $(call ...) is available. This allows users to create
445 their own parameterized macros and invoke them later. Original
446 implementation of this function was provided by Han-Wen Nienhuys
449 * A new function $(if ...) is available. It provides if-then-else
450 capabilities in a builtin function. Original implementation of this
451 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
453 * Make defines a new variable, .LIBPATTERNS. This variable controls how
454 library dependency expansion (dependencies like ``-lfoo'') is performed.
456 * Make accepts CRLF sequences as well as traditional LF, for
457 compatibility with makefiles created on other operating systems.
459 * Make accepts a new option: -R, or --no-builtin-variables. This option
460 disables the definition of the rule-specific builtin variables (CC,
461 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
464 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
466 On systems that support POSIX pipe(2) semantics, GNU make can now pass
467 -jN options to submakes rather than forcing them all to use -j1. The
468 top make and all its sub-make processes use a pipe to communicate with
469 each other to ensure that no more than N jobs are started across all
470 makes. To get the old behavior of -j back, you can configure make
471 with the --disable-job-server option.
473 * The confusing term "dependency" has been replaced by the more accurate
474 and standard term "prerequisite", both in the manual and in all GNU make
477 * GNU make supports the "big archive" library format introduced in AIX 4.3.
479 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
480 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
481 support for Solaris and Linux was introduced in 3.77, but the
482 configuration had issues: these have also been resolved).
484 * The Windows 95/98/NT (W32) version of GNU make now has native support
485 for the Cygnus Cygwin release B20.1 shell (bash).
487 * The GNU make regression test suite, long available separately "under
488 the table", has been integrated into the release. You can invoke it
489 by running "make check" in the distribution. Note that it requires
490 Perl (either Perl 4 or Perl 5) to run.
494 * Implement BSD make's "?=" variable assignment operator. The variable
495 is assigned the specified value only if that variable is not already
498 * Make defines a new variable, "CURDIR", to contain the current working
499 directory (after the -C option, if any, has been processed).
500 Modifying this variable has no effect on the operation of make.
502 * Make defines a new default RCS rule, for new-style master file
503 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
505 Make defines new default rules for DOS-style C++ file naming
506 conventions, with ``.cpp'' suffixes. All the same rules as for
507 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
508 COMPILE.cpp macros (which default to the same value as LINK.cc and
509 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
510 use CXXFLAGS to change C++ compiler flags.
512 * A new feature, "target-specific variable values", has been added.
513 This is a large change so please see the appropriate sections of the
514 manual for full details. Briefly, syntax like this:
516 TARGET: VARIABLE = VALUE
518 defines VARIABLE as VALUE within the context of TARGET. This is
519 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
520 that the assignment may be of any type, not just recursive, and that
521 the override keyword is available.
523 COMPATIBILITY: This new syntax means that if you have any rules where
524 the first or second dependency has an equal sign (=) in its name,
525 you'll have to escape them with a backslash: "foo : bar\=baz".
526 Further, if you have any dependencies which already contain "\=",
527 you'll have to escape both of them: "foo : bar\\\=baz".
529 * A new appendix listing the most common error and warning messages
530 generated by GNU make, with some explanation, has been added to the
531 GNU make User's Manual.
533 * Updates to the GNU make Customs library support (see README.customs).
535 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
536 and to the DOS port from Eli Zaretski (see README.DOS).
540 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
544 * GNU make now uses automake to control Makefile.in generation. This
545 should make it more consistent with the GNU standards.
547 * VPATH functionality has been changed to incorporate the VPATH+ patch,
548 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
551 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
552 were specified on the command line, if any. Modifying this variable
553 has no effect on the operation of make.
555 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
556 list of words from number S to number E (inclusive) of TEXT.
558 * Instead of an error, detection of future modification times gives a
559 warning and continues. The warning is repeated just before GNU make
560 exits, so it is less likely to be lost.
562 * Fix the $(basename) and $(suffix) functions so they only operate on
563 the last filename, not the entire string:
565 Command Old Result New Result
566 ------- ---------- ----------
568 $(basename a.b/c) a a.b/c
570 $(suffix a.b/c) b/c <empty>
572 * The $(strip) function now removes newlines as well as TABs and spaces.
574 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
577 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
579 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
580 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
581 and utilities. See README.DOS for details, and direct all questions
582 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
583 Delorie <dj@delorie.com>.
585 * John W. Eaton has updated the VMS port to support libraries and VPATH.
589 * The directory messages printed by `-w' and implicitly in sub-makes,
590 are now omitted if Make runs no commands and has no other messages to print.
592 * Make now detects files that for whatever reason have modification times
593 in the future and gives an error. Files with such impossible timestamps
594 can result from unsynchronized clocks, or archived distributions
595 containing bogus timestamps; they confuse Make's dependency engine
598 * The new directive `sinclude' is now recognized as another name for
599 `-include', for compatibility with some other Makes.
601 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
602 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
604 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
605 See README.W32 for details, and direct all Windows-related questions to
606 <rob_tulloh@tivoli.com>.
610 * Converted to use Autoconf version 2, so `configure' has some new options.
611 See INSTALL for details.
613 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
614 output enabled by -d, at any time during the run.
618 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
619 He is maintaining the DOS port, not the GNU Make maintainer;
620 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
621 MS-DOS binaries are available for FTP from ftp.simtel.net in
622 /pub/simtelnet/gnu/djgpp/.
624 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
625 contain variable definitions itself; these are treated just like
626 command line variable definitions. Make will automatically insert any
627 variable definitions from the environment value of `MAKEFLAGS' or from
628 the command line, into the `MAKEFLAGS' value exported to children. The
629 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
630 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
631 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
632 in the environment when its size is limited.
634 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
635 a rule if it has changed when its recipe exits with a nonzero status,
636 just as when the recipe gets a signal.
638 * The automatic variable `$+' is new. It lists all the dependencies like
639 `$^', but preserves duplicates listed in the makefile. This is useful
640 for linking rules, where library files sometimes need to be listed twice
643 * You can now specify the `.IGNORE' and `.SILENT' special targets with
644 dependencies to limit their effects to those files. If a file appears as
645 a dependency of `.IGNORE', then errors will be ignored while running the
646 recipe to update that file. Likewise if a file appears as a dependency
647 of `.SILENT', then the recipe to update that file will not be printed
648 before it is run. (This change was made to conform to POSIX.2.)
652 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
653 `$(^D)' now omit the trailing slash from the directory name. (This change
654 was made to comply with POSIX.2.)
656 * The source distribution now includes the Info files for the Make manual.
657 There is no longer a separate distribution containing Info and DVI files.
659 * You can now set the variables `binprefix' and/or `manprefix' in
660 Makefile.in (or on the command line when installing) to install GNU make
661 under a name other than `make' (i.e., ``make binprefix=g install''
662 installs GNU make as `gmake').
664 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
665 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
668 * The exit status of Make when it runs into errors is now 2 instead of 1.
669 The exit status is 1 only when using -q and some target is not up to date.
670 (This change was made to comply with POSIX.2.)
674 * It is no longer a fatal error to have a NUL character in a makefile.
675 You should never put a NUL in a makefile because it can have strange
676 results, but otherwise empty lines full of NULs (such as produced by
677 the `xmkmf' program) will always work fine.
679 * The error messages for nonexistent included makefiles now refer to the
680 makefile name and line number where the `include' appeared, so Emacs's
681 C-x ` command takes you there (in case it's a typo you need to fix).
685 * Implicit rule search for archive member references is now done in the
686 opposite order from previous versions: the whole target name `LIB(MEM)'
687 first, and just the member name and parentheses `(MEM)' second.
689 * Make now gives an error for an unterminated variable or function reference.
690 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
692 * The new default variable `MAKE_VERSION' gives the version number of
693 Make, and a string describing the remote job support compiled in (if any).
694 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
696 * Commands in an invocation of the `shell' function are no longer run
697 with a modified environment like recipes are. As in versions before
698 3.68, they now run with the environment that `make' started with. We
699 have reversed the change made in version 3.68 because it turned out to
700 cause a paradoxical situation in cases like:
702 export variable = $(shell echo value)
704 When Make attempted to put this variable in the environment for a
705 recipe, it would try expand the value by running the shell command
706 `echo value'. In version 3.68, because it constructed an environment
707 for that shell command in the same way, Make would begin to go into an
708 infinite loop and then get a fatal error when it detected the loop.
710 * The recipe given for `.DEFAULT' is now used for phony targets with no
715 * You can list several archive member names inside parenthesis:
716 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
718 * You can use wildcards inside archive member references. For example,
719 `lib(*.o)' expands to all existing members of `lib' whose names end in
720 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
721 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
722 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
724 * A suffix rule `.X.a' now produces two pattern rules:
725 (%.o): %.X # Previous versions produced only this.
726 %.a: %.X # Now produces this as well, just like other suffixes.
728 * The new flag `--warn-undefined-variables' says to issue a warning message
729 whenever Make expands a reference to an undefined variable.
731 * The new `-include' directive is just like `include' except that there is
732 no error (not even a warning) for a nonexistent makefile.
734 * Commands in an invocation of the `shell' function are now run with a
735 modified environment like recipes are, so you can use `export' et al
736 to set up variables for them. They used to run with the environment
737 that `make' started with.
741 * `make --version' (or `make -v') now exits immediately after printing
746 * Make now supports long-named members in `ar' archive files.
750 * Make now supports the `+=' syntax for a variable definition which appends
751 to the variable's previous value. See the section `Appending More Text
752 to Variables' in the manual for full details.
754 * The new option `--no-print-directory' inhibits the `-w' or
755 `--print-directory' feature. Make turns on `--print-directory'
756 automatically if you use `-C' or `--directory', and in sub-makes; some
757 users have found this behavior undesirable.
759 * The built-in implicit rules now support the alternative extension
760 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
764 * Make now uses a standard GNU `configure' script. See the new file
765 INSTALL for the new (and much simpler) installation procedure.
767 * There is now a shell script to build Make the first time, if you have no
768 other `make' program. `build.sh' is created by `configure'; see README.
770 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
772 * Elements of the `$^' and `$?' automatic variables that are archive
773 member references now list only the member name, as in Unix and POSIX.2.
775 * You should no longer ever need to specify the `-w' switch, which prints
776 the current directory before and after Make runs. The `-C' switch to
777 change directory, and recursive use of Make, now set `-w' automatically.
779 * Multiple double-colon rules for the same target will no longer have their
780 recipes run simultaneously under -j, as this could result in the two
781 recipes trying to change the file at the same time and interfering with
784 * The `SHELL' variable is now never taken from the environment.
785 Each makefile that wants a shell other than the default (/bin/sh) must
786 set SHELL itself. SHELL is always exported to child processes.
787 This change was made for compatibility with POSIX.2.
789 * Make now accepts long options. There is now an informative usage message
790 that tells you what all the options are and what they do. Try `make --help'.
792 * There are two new directives: `export' and `unexport'. All variables are
793 no longer automatically put into the environments of the recipe lines that
794 Make runs. Instead, only variables specified on the command line or in
795 the environment are exported by default. To export others, use:
797 or you can define variables with:
798 export VARIABLE = VALUE
800 export VARIABLE := VALUE
804 .EXPORT_ALL_VARIABLES:
805 to get the old behavior. See the node `Variables/Recursion' in the manual
806 for a full description.
808 * The recipe from the `.DEFAULT' special target is only applied to
809 targets which have no rules at all, not all targets with no recipe.
810 This change was made for compatibility with Unix make.
812 * All fatal error messages now contain `***', so they are easy to find in
815 * Dependency file names like `-lNAME' are now replaced with the actual file
816 name found, as with files found by normal directory search (VPATH).
817 The library file `libNAME.a' may now be found in the current directory,
818 which is checked before VPATH; the standard set of directories (/lib,
819 /usr/lib, /usr/local/lib) is now checked last.
820 See the node `Libraries/Search' in the manual for full details.
822 * A single `include' directive can now specify more than one makefile to
825 You can also use shell file name patterns in an `include' directive:
828 * The default directories to search for included makefiles, and for
829 libraries specified with `-lNAME', are now set by configuration.
831 * You can now use blanks as well as colons to separate the directories in a
832 search path for the `vpath' directive or the `VPATH' variable.
834 * You can now use variables and functions in the left hand side of a
835 variable assignment, as in "$(foo)bar = value".
837 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
838 The `MAKE_COMMAND' variable is now defined to the name with which make
841 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
842 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
843 problems with shells that cannot have `+' in environment variable names.
845 * The value of a recursively expanded variable is now expanded when putting
846 it into the environment for child processes. This change was made for
847 compatibility with Unix make.
849 * A rule with no targets before the `:' is now accepted and ignored.
850 This change was made for compatibility with SunOS 4 make.
851 We do not recommend that you write your makefiles to take advantage of this.
853 * The `-I' switch can now be used in MAKEFLAGS, and are put there
854 automatically just like other switches.
858 * Built-in rules for C++ source files with the `.C' suffix.
859 We still recommend that you use `.cc' instead.
861 * If a recipe is given too many times for a single target, the last one
862 given is used, and a warning message is printed.
864 * Error messages about makefiles are in standard GNU error format,
865 so C-x ` in Emacs works on them.
867 * Dependencies of pattern rules which contain no % need not actually exist
868 if they can be created (just like dependencies which do have a %).
872 * A message is always printed when Make decides there is nothing to be done.
873 It used to be that no message was printed for top-level phony targets
874 (because "`phony' is up to date" isn't quite right). Now a different
875 message "Nothing to be done for `phony'" is printed in that case.
877 * Archives on AIX now supposedly work.
879 * When the recipes specified for .DEFAULT are used to update a target,
880 the $< automatic variable is given the same value as $@ for that target.
881 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
885 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
886 variables while remaking makefiles, so recursive makes done while remaking
887 makefiles will behave properly.
889 * If the special target `.NOEXPORT' is specified in a makefile,
890 only variables that came from the environment and variables
891 defined on the command line are exported.
895 * Suffix rules may have dependencies (which are ignored).
899 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
900 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
904 * There is now a Unix man page for GNU Make. It is certainly not a
905 replacement for the Texinfo manual, but it documents the basic
906 functionality and the switches. For full documentation, you should
907 still read the Texinfo manual. Thanks to Dennis Morse of Stanford
908 University for contributing the initial version of this.
910 * Variables which are defined by default (e.g., `CC') will no longer be
911 put into the environment for child processes. (If these variables are
912 reset by the environment, makefiles, or the command line, they will
913 still go into the environment.)
915 * Makefiles which have recipes but no dependencies (and thus are always
916 considered out of date and in need of remaking), will not be remade (if they
917 were being remade only because they were makefiles). This means that GNU
918 Make will no longer go into an infinite loop when fed the makefiles that
919 `imake' (necessary to build X Windows) produces.
921 * There is no longer a warning for using the `vpath' directive with an explicit
922 pathname (instead of a `%' pattern).
926 * When removing intermediate files, only one `rm' command line is printed,
927 listing all file names.
929 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
930 These are the directory-only and file-only versions of `$^' and `$?'.
932 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
933 directory if it exists.
935 * The automatic variable `$($/)' is no longer defined.
937 * Leading `+' characters on a recipe line make that line be executed even
938 under -n, -t, or -q (as if the line contained `$(MAKE)').
940 * For recipe lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
941 only those lines are executed, not the entire recipe.
942 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
946 * Filenames in rules will now have ~ and ~USER expanded.
948 * The `-p' output has been changed so it can be used as a makefile.
949 (All information that isn't specified by makefiles is prefaced with comment
954 * The % character can be quoted with backslash in implicit pattern rules,
955 static pattern rules, `vpath' directives, and `patsubst', `filter', and
956 `filter-out' functions. A warning is issued if a `vpath' directive's
957 pattern contains no %.
959 * The `wildcard' variable expansion function now expands ~ and ~USER.
961 * Messages indicating failed recipe lines now contain the target name:
962 make: *** [target] Error 1
964 * The `-p' output format has been changed somewhat to look more like
965 makefile rules and to give all information that Make has about files.
971 * The `-l' switch with no argument removes any previous load-average limit.
973 * When the `-w' switch is in effect, and Make has updated makefiles,
974 it will write a `Leaving directory' message before re-executing itself.
975 This makes the `directory change tracking' changes to Emacs's compilation
976 commands work properly.
980 * The automatic variable `$*' is now defined for explicit rules,
981 as it is in Unix make.
985 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
986 specified without an argument (indicating infinite jobs).
987 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
989 * Make no longer checks hashed directories after running recipes.
990 The behavior implemented in 3.41 caused too much slowdown.
994 * A dependency is NOT considered newer than its dependent if
995 they have the same modification time. The behavior implemented
996 in 3.43 conflicts with RCS.
1000 * Dependency loops are no longer fatal errors.
1002 * A dependency is considered newer than its dependent if
1003 they have the same modification time.
1007 * The variables F77 and F77FLAGS are now set by default to $(FC) and
1008 $(FFLAGS). Makefiles designed for System V make may use these variables in
1009 explicit rules and expect them to be set. Unfortunately, there is no way to
1010 make setting these affect the Fortran implicit rules unless FC and FFLAGS
1011 are not used (and these are used by BSD make).
1015 * Make now checks to see if its hashed directories are changed by recipes.
1016 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
1020 * The `shell' function no longer captures standard error output.
1024 * A file beginning with a dot can be the default target if it also contains
1025 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
1029 * Archive member names are truncated to 15 characters.
1031 * Yet more USG stuff.
1033 * Minimal support for Microport System V (a 16-bit machine and a
1034 brain-damaged compiler). This has even lower priority than other USG
1035 support, so if it gets beyond trivial, I will take it out completely.
1037 * Revamped default implicit rules (not much visible change).
1039 * The -d and -p options can come from the environment.
1043 * Improved support for USG and HPUX (hopefully).
1045 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
1046 equivalent to `$(patsubst a,b,$(foo))'.
1048 * Defining .DEFAULT with no deps or recipe clears its recipe.
1050 * New default implicit rules for .S (cpp, then as), and .sh (copy and
1051 make executable). All default implicit rules that use cpp (even
1052 indirectly), use $(CPPFLAGS).
1056 * Giving the -j option with no arguments gives you infinite jobs.
1060 * New option: "-l LOAD" says not to start any new jobs while others are
1061 running if the load average is not below LOAD (a floating-point number).
1063 * There is support in place for implementations of remote command execution
1064 in Make. See the file remote.c.
1068 * No more than 10 directories will be kept open at once.
1069 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
1073 * Archive files will have their modification times recorded before doing
1074 anything that might change their modification times by updating an archive
1079 * The `MAKELEVEL' variable is defined for use by makefiles.
1083 * The recursion level indications in error messages are much shorter than
1084 they were in version 3.14.
1088 * Leading spaces before directives are ignored (as documented).
1090 * Included makefiles can determine the default goal target.
1091 (System V Make does it this way, so we are being compatible).
1095 * Variables that are defaults built into Make will not be put in the
1096 environment for children. This just saves some environment space and,
1097 except under -e, will be transparent to sub-makes.
1099 * Error messages from sub-makes will indicate the level of recursion.
1101 * Hopefully some speed-up for large directories due to a change in the
1102 directory hashing scheme.
1104 * One child will always get a standard input that is usable.
1106 * Default makefiles that don't exist will be remade and read in.
1110 * Count parentheses inside expansion function calls so you can
1111 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
1115 * Several bug fixes, including USG and Sun386i support.
1117 * `shell' function to expand shell commands a la `
1119 * If the `-d' flag is given, version information will be printed.
1121 * The `-c' option has been renamed to `-C' for compatibility with tar.
1123 * The `-p' option no longer inhibits other normal operation.
1125 * Makefiles will be updated and re-read if necessary.
1127 * Can now run several recipes at once (parallelism), -j option.
1129 * Error messages will contain the level of Make recursion, if any.
1131 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
1134 * A double-colon rule with no dependencies will always have its recipe run.
1135 (This is how both the BSD and System V versions of Make do it.)
1139 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
1141 -------------------------------------------------------------------------------
1142 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1143 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
1144 2010 Free Software Foundation, Inc. This file is part of GNU Make.
1146 GNU Make is free software; you can redistribute it and/or modify it under the
1147 terms of the GNU General Public License as published by the Free Software
1148 Foundation; either version 3 of the License, or (at your option) any later
1151 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1152 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1153 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1155 You should have received a copy of the GNU General Public License along with
1156 this program. If not, see <http://www.gnu.org/licenses/>.