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 * Compiling GNU make now requires a conforming ISO C 1989 compiler and
15 standard runtime library.
17 * WARNING: Backward-incompatibility!
18 The '$?' variable now contains all prerequisites that caused the target to
19 be considered out of date, even if they do not exist (previously only
20 existing targets were provided in $?).
22 * WARNING: Backward-incompatibility!
23 As a result of parser enhancements, three backward-compatibility issues
24 exist: first, a prerequisite containing an "=" cannot be escaped with a
25 backslash any longer. You must create a variable containing an "=" and use
26 that variable in the prerequisite. Second, variable names can no longer
27 contain whitespace, unless you put the whitespace in a variable and use the
28 variable. Third, in previous versions of make it was sometimes not flagged
29 as an error for explicit and pattern targets to appear in the same rule.
30 Now this is always reported as an error.
32 * WARNING: Backward-incompatibility!
33 The pattern-specific variables and pattern rules are now applied in the
34 shortest stem first order instead of the definition order (variables
35 and rules with the same stem length are still applied in the definition
36 order). This produces the usually-desired behavior where more specific
37 patterns are preferred. To detect this feature search for 'shortest-stem'
38 in the .FEATURES special variable.
40 * WARNING: Backward-incompatibility!
41 The library search behavior has changed to be compatible with the standard
42 linker behavior. Prior to this version for prerequisites specified using
43 the -lfoo syntax make fist searched for libfoo.so in the current directory,
44 vpath directories, and system directories. If that didn't yield a match,
45 make then searched for libfoo.a in these directories. Starting with this
46 version make searches first for libfoo.so and then for libfoo.a in each
47 of these directories in order.
49 * New command line option: --eval=STRING causes STRING to be evaluated as
50 makefile syntax (akin to using the $(eval ...) function). The evaluation is
51 performed after all default rules and variables are defined, but before any
54 * New special variable: .RECIPEPREFIX allows you to reset the recipe
55 introduction character from the default (TAB) to something else. The first
56 character of this variable value is the new recipe introduction character.
57 If the variable is set to the empty string, TAB is used again. It can be
58 set and reset at will; recipes will use the value active when they were
59 first parsed. To detect this feature check the value of $(.RECIPEPREFIX).
61 * New variable modifier 'private': prefixing a variable assignment with the
62 modifier 'private' suppresses inheritance of that variable by
63 prerequisites. This is most useful for target- and pattern-specific
66 * New make directive: 'undefine' allows you to undefine a variable so
67 that it appears as if it was never set. Both $(flavor) and $(origin)
68 functions will return 'undefined' for such a variable. To detect this
69 feature search for 'undefine in the .FEATURES special variable.
71 * The parser for variable assignments has been enhanced to allow multiple
72 modifiers ('export', 'override', 'private') on the same line as variables,
73 including define/endef variables, and in any order. Also, it is possible
74 to create variables and targets named as these modifiers.
79 * GNU make is ported to OS/2.
81 * GNU make is ported to MinGW. The MinGW build is only supported by
82 the build_w32.bat batch file; see the file README.W32 for more
85 * WARNING: Future backward-incompatibility!
86 Up to and including this release, the '$?' variable does not contain
87 any prerequisite that does not exist, even though that prerequisite
88 might have caused the target to rebuild. Starting with the _next_
89 release of GNU make, '$?' will contain all prerequisites that caused
90 the target to be considered out of date. See this Savannah bug:
91 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
93 * WARNING: Backward-incompatibility!
94 GNU make now implements a generic "second expansion" feature on the
95 prerequisites of both explicit and implicit (pattern) rules. In order
96 to enable this feature, the special target '.SECONDEXPANSION' must be
97 defined before the first target which takes advantage of it. If this
98 feature is enabled then after all rules have been parsed the
99 prerequisites are expanded again, this time with all the automatic
100 variables in scope. This means that in addition to using standard
101 SysV $$@ in prerequisites lists, you can also use complex functions
102 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
103 as well, where the second expansion occurs when the rule is matched.
104 However, this means that when '.SECONDEXPANSION' is enabled you must
105 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
106 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
107 which used to be available by default, is now ONLY available when the
108 .SECONDEXPANSION target is defined. If your makefiles take advantage
109 of this SysV feature you will need to update them.
111 * WARNING: Backward-incompatibility!
113 In order to comply with POSIX, the way in which GNU make processes
114 backslash-newline sequences in recipes has changed. If your makefiles
115 use backslash-newline sequences inside of single-quoted strings in
116 recipes you will be impacted by this change. See the GNU make manual
117 subsection "Splitting Recipe Lines" (node "Splitting Lines"), in
118 section "Recipe Syntax", chapter "Writing Recipe in Rules", for
121 * WARNING: Backward-incompatibility!
122 Some previous versions of GNU make had a bug where "#" in a function
123 invocation such as $(shell ...) was treated as a make comment. A
124 workaround was to escape these with backslashes. This bug has been
125 fixed: if your makefile uses "\#" in a function invocation the
126 backslash is now preserved, so you'll need to remove it.
128 * New command line option: -L (--check-symlink-times). On systems that
129 support symbolic links, if this option is given then GNU make will
130 use the most recent modification time of any symbolic links that are
131 used to resolve target files. The default behavior remains as it
132 always has: use the modification time of the actual target file only.
134 * The "else" conditional line can now be followed by any other valid
135 conditional on the same line: this does not increase the depth of the
136 conditional nesting, so only one "endif" is required to close the
139 * All pattern-specific variables that match a given target are now used
140 (previously only the first match was used).
142 * Target-specific variables can be marked as exportable using the
145 * In a recursive $(call ...) context, any extra arguments from the outer
146 call are now masked in the context of the inner call.
148 * Implemented a solution for the "thundering herd" problem with "-j -l".
149 This version of GNU make uses an algorithm suggested by Thomas Riedl
150 <thomas.riedl@siemens.com> to track the number of jobs started in the
151 last second and artificially adjust GNU make's view of the system's
152 load average accordingly.
154 * New special variables available in this release:
155 - .INCLUDE_DIRS: Expands to a list of directories that make searches
156 for included makefiles.
157 - .FEATURES: Contains a list of special features available in this
159 - .DEFAULT_GOAL: Set the name of the default goal make will
160 use if no goals are provided on the command line.
161 - MAKE_RESTARTS: If set, then this is the number of times this
162 instance of make has been restarted (see "How Makefiles Are Remade"
164 - New automatic variable: $| (added in 3.80, actually): contains all
165 the order-only prerequisites defined for the target.
167 * New functions available in this release:
168 - $(lastword ...) returns the last word in the list. This gives
169 identical results as $(word $(words ...) ...), but is much faster.
170 - $(abspath ...) returns the absolute path (all "." and ".."
171 directories resolved, and any duplicate "/" characters removed) for
173 - $(realpath ...) returns the canonical pathname for each path
174 provided. The canonical pathname is the absolute pathname, with
175 all symbolic links resolved as well.
176 - $(info ...) prints its arguments to stdout. No makefile name or
177 line number info, etc. is printed.
178 - $(flavor ...) returns the flavor of a variable.
179 - $(or ...) provides a short-circuiting OR conditional: each argument
180 is expanded. The first true (non-empty) argument is returned; no
181 further arguments are expanded. Expands to empty if there are no
183 - $(and ...) provides a short-circuiting AND conditional: each
184 argument is expanded. The first false (empty) argument is
185 returned; no further arguments are expanded. Expands to the last
186 argument if all arguments are true.
188 * Changes made for POSIX compatibility:
189 - Only touch targets (under -t) if they have a recipe.
190 - Setting the SHELL make variable does NOT change the value of the
191 SHELL environment variable given to programs invoked by make. As
192 an enhancement to POSIX, if you export the make variable SHELL then
193 it will be set in the environment, just as before.
195 * On MS Windows systems, explicitly setting SHELL to a pathname ending
196 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
197 the DOS command interpreter in batch mode even if a UNIX-like shell
198 could be found on the system.
200 * On VMS there is now support for case-sensitive filesystems such as ODS5.
201 See the readme.vms file for information.
203 * Parallel builds (-jN) no longer require a working Bourne shell on
204 Windows platforms. They work even with the stock Windows shells, such
205 as cmd.exe and command.com.
207 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
208 should not be impacted.
210 * New translations for Swedish, Chinese (simplified), Ukrainian,
211 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
214 A complete list of bugs fixed in this version is available here:
216 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
221 * A new feature exists: order-only prerequisites. These prerequisites
222 affect the order in which targets are built, but they do not impact
223 the rebuild/no-rebuild decision of their dependents. That is to say,
224 they allow you to require target B be built before target A, without
225 requiring that target A will always be rebuilt if target B is updated.
226 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
228 * For compatibility with SysV make, GNU make now supports the peculiar
229 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
230 This syntax is only valid within explicit and static pattern rules: it
231 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
232 <egp@free.fr> provided a patch implementing this feature; however, I
233 decided to implement it in a different way.
235 * The argument to the "ifdef" conditional is now expanded before it's
236 tested, so it can be a constructed variable name.
238 Similarly, the arguments to "export" (when not used in a variable
239 definition context) and "unexport" are also now expanded.
241 * A new function is defined: $(value ...). The argument to this
242 function is the _name_ of a variable. The result of the function is
243 the value of the variable, without having been expanded.
245 * A new function is defined: $(eval ...). The arguments to this
246 function should expand to makefile commands, which will then be
247 evaluated as if they had appeared in the makefile. In combination
248 with define/endef multiline variable definitions this is an extremely
249 powerful capability. The $(value ...) function is also sometimes
252 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
253 list of each makefile GNU make has read, or started to read, in the
254 order in which they were encountered. So, the last filename in the
255 list when a makefile is just being read (before any includes) is the
256 name of the current makefile.
258 * A new built-in variable is defined: $(.VARIABLES). When it is
259 expanded it returns a complete list of variable names defined by all
260 makefiles at that moment.
262 * A new command line option is defined, -B or --always-make. If
263 specified GNU make will consider all targets out-of-date even if they
264 would otherwise not be.
266 * The arguments to $(call ...) functions were being stored in $1, $2,
267 etc. as recursive variables, even though they are fully expanded
268 before assignment. This means that escaped dollar signs ($$ etc.)
269 were not behaving properly. Now the arguments are stored as simple
270 variables. This may mean that if you added extra escaping to your
271 $(call ...) function arguments you will need to undo it now.
273 * The variable invoked by $(call ...) can now be recursive: unlike other
274 variables it can reference itself and this will not produce an error
275 when it is used as the first argument to $(call ...) (but only then).
277 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
278 option --disable-nsec-timestamps. You might need this if your build
279 process depends on tools like "cp -p" preserving time stamps, since
280 "cp -p" (right now) doesn't preserve the subsecond portion of a time
283 * Updated translations for French, Galician, German, Japanese, Korean,
284 and Russian. New translations for Croatian, Danish, Hebrew, and
287 * Updated internationalization support to Gettext 0.11.5.
288 GNU make now uses Gettext's "external" feature, and does not include
289 any internationalization code itself. Configure will search your
290 system for an existing implementation of GNU Gettext (only GNU Gettext
291 is acceptable) and use it if it exists. If not, NLS will be disabled.
292 See ABOUT-NLS for more information.
294 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
296 A complete list of bugs fixed in this version is available here:
298 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
303 * .SECONDARY with no prerequisites now prevents any target from being
304 removed because make thinks it's an intermediate file, not just those
305 listed in the makefile.
307 * New configure option --disable-nsec-timestamps, but this was
308 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
312 * GNU make optionally supports internationalization and locales via the
313 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
314 file for more information on configuring GNU make for NLS.
316 * Previously, GNU make quoted variables such as MAKEFLAGS and
317 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
318 be used within make build scripts. However, using them there is not
319 proper behavior: they are meant to be passed to subshells via the
320 environment. Unfortunately the values were not quoted properly to be
321 passed through the environment. This meant that make didn't properly
322 pass some types of command line values to submakes.
324 With this version we change that behavior: now these variables are
325 quoted properly for passing through the environment, which is the
326 correct way to do it. If you previously used these variables
327 explicitly within a make rule you may need to re-examine your use for
328 correctness given this change.
330 * A new pseudo-target .NOTPARALLEL is available. If defined, the
331 current makefile is run serially regardless of the value of -j.
332 However, submakes are still eligible for parallel execution.
334 * The --debug option has changed: it now allows optional flags
335 controlling the amount and type of debugging output. By default only
336 a minimal amount information is generated, displaying the names of
337 "normal" targets (not makefiles) that were deemed out of date and in
338 need of being rebuilt.
340 Note that the -d option behaves as before: it takes no arguments and
341 all debugging information is generated.
343 * The `-p' (print database) output now includes filename and linenumber
344 information for variable definitions, to aid debugging.
346 * The wordlist function no longer reverses its arguments if the "start"
347 value is greater than the "end" value. If that's true, nothing is
350 * Hartmut Becker provided many updates for the VMS port of GNU make.
351 See the readme.vms file for more details.
355 * Two new functions, $(error ...) and $(warning ...) are available. The
356 former will cause make to fail and exit immediately upon expansion of
357 the function, with the text provided as the error message. The latter
358 causes the text provided to be printed as a warning message, but make
361 * A new function $(call ...) is available. This allows users to create
362 their own parameterized macros and invoke them later. Original
363 implementation of this function was provided by Han-Wen Nienhuys
366 * A new function $(if ...) is available. It provides if-then-else
367 capabilities in a builtin function. Original implementation of this
368 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
370 * Make defines a new variable, .LIBPATTERNS. This variable controls how
371 library dependency expansion (dependencies like ``-lfoo'') is performed.
373 * Make accepts CRLF sequences as well as traditional LF, for
374 compatibility with makefiles created on other operating systems.
376 * Make accepts a new option: -R, or --no-builtin-variables. This option
377 disables the definition of the rule-specific builtin variables (CC,
378 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
381 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
383 On systems that support POSIX pipe(2) semantics, GNU make can now pass
384 -jN options to submakes rather than forcing them all to use -j1. The
385 top make and all its sub-make processes use a pipe to communicate with
386 each other to ensure that no more than N jobs are started across all
387 makes. To get the old behavior of -j back, you can configure make
388 with the --disable-job-server option.
390 * The confusing term "dependency" has been replaced by the more accurate
391 and standard term "prerequisite", both in the manual and in all GNU make
394 * GNU make supports the "big archive" library format introduced in AIX 4.3.
396 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
397 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
398 support for Solaris and Linux was introduced in 3.77, but the
399 configuration had issues: these have also been resolved).
401 * The Windows 95/98/NT (W32) version of GNU make now has native support
402 for the Cygnus Cygwin release B20.1 shell (bash).
404 * The GNU make regression test suite, long available separately "under
405 the table", has been integrated into the release. You can invoke it
406 by running "make check" in the distribution. Note that it requires
407 Perl (either Perl 4 or Perl 5) to run.
411 * Implement BSD make's "?=" variable assignment operator. The variable
412 is assigned the specified value only if that variable is not already
415 * Make defines a new variable, "CURDIR", to contain the current working
416 directory (after the -C option, if any, has been processed).
417 Modifying this variable has no effect on the operation of make.
419 * Make defines a new default RCS rule, for new-style master file
420 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
422 Make defines new default rules for DOS-style C++ file naming
423 conventions, with ``.cpp'' suffixes. All the same rules as for
424 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
425 COMPILE.cpp macros (which default to the same value as LINK.cc and
426 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
427 use CXXFLAGS to change C++ compiler flags.
429 * A new feature, "target-specific variable values", has been added.
430 This is a large change so please see the appropriate sections of the
431 manual for full details. Briefly, syntax like this:
433 TARGET: VARIABLE = VALUE
435 defines VARIABLE as VALUE within the context of TARGET. This is
436 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
437 that the assignment may be of any type, not just recursive, and that
438 the override keyword is available.
440 COMPATIBILITY: This new syntax means that if you have any rules where
441 the first or second dependency has an equal sign (=) in its name,
442 you'll have to escape them with a backslash: "foo : bar\=baz".
443 Further, if you have any dependencies which already contain "\=",
444 you'll have to escape both of them: "foo : bar\\\=baz".
446 * A new appendix listing the most common error and warning messages
447 generated by GNU make, with some explanation, has been added to the
448 GNU make User's Manual.
450 * Updates to the GNU make Customs library support (see README.customs).
452 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
453 and to the DOS port from Eli Zaretski (see README.DOS).
457 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
461 * GNU make now uses automake to control Makefile.in generation. This
462 should make it more consistent with the GNU standards.
464 * VPATH functionality has been changed to incorporate the VPATH+ patch,
465 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
468 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
469 were specified on the command line, if any. Modifying this variable
470 has no effect on the operation of make.
472 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
473 list of words from number S to number E (inclusive) of TEXT.
475 * Instead of an error, detection of future modification times gives a
476 warning and continues. The warning is repeated just before GNU make
477 exits, so it is less likely to be lost.
479 * Fix the $(basename) and $(suffix) functions so they only operate on
480 the last filename, not the entire string:
482 Command Old Result New Result
483 ------- ---------- ----------
485 $(basename a.b/c) a a.b/c
487 $(suffix a.b/c) b/c <empty>
489 * The $(strip) function now removes newlines as well as TABs and spaces.
491 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
494 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
496 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
497 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
498 and utilities. See README.DOS for details, and direct all questions
499 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
500 Delorie <dj@delorie.com>.
502 * John W. Eaton has updated the VMS port to support libraries and VPATH.
506 * The directory messages printed by `-w' and implicitly in sub-makes,
507 are now omitted if Make runs no commands and has no other messages to print.
509 * Make now detects files that for whatever reason have modification times
510 in the future and gives an error. Files with such impossible timestamps
511 can result from unsynchronized clocks, or archived distributions
512 containing bogus timestamps; they confuse Make's dependency engine
515 * The new directive `sinclude' is now recognized as another name for
516 `-include', for compatibility with some other Makes.
518 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
519 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
521 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
522 See README.W32 for details, and direct all Windows-related questions to
523 <rob_tulloh@tivoli.com>.
527 * Converted to use Autoconf version 2, so `configure' has some new options.
528 See INSTALL for details.
530 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
531 output enabled by -d, at any time during the run.
535 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
536 He is maintaining the DOS port, not the GNU Make maintainer;
537 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
538 MS-DOS binaries are available for FTP from ftp.simtel.net in
539 /pub/simtelnet/gnu/djgpp/.
541 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
542 contain variable definitions itself; these are treated just like
543 command line variable definitions. Make will automatically insert any
544 variable definitions from the environment value of `MAKEFLAGS' or from
545 the command line, into the `MAKEFLAGS' value exported to children. The
546 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
547 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
548 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
549 in the environment when its size is limited.
551 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
552 a rule if it has changed when its recipe exits with a nonzero status,
553 just as when the recipe gets a signal.
555 * The automatic variable `$+' is new. It lists all the dependencies like
556 `$^', but preserves duplicates listed in the makefile. This is useful
557 for linking rules, where library files sometimes need to be listed twice
560 * You can now specify the `.IGNORE' and `.SILENT' special targets with
561 dependencies to limit their effects to those files. If a file appears as
562 a dependency of `.IGNORE', then errors will be ignored while running the
563 recipe to update that file. Likewise if a file appears as a dependency
564 of `.SILENT', then the recipe to update that file will not be printed
565 before it is run. (This change was made to conform to POSIX.2.)
569 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
570 `$(^D)' now omit the trailing slash from the directory name. (This change
571 was made to comply with POSIX.2.)
573 * The source distribution now includes the Info files for the Make manual.
574 There is no longer a separate distribution containing Info and DVI files.
576 * You can now set the variables `binprefix' and/or `manprefix' in
577 Makefile.in (or on the command line when installing) to install GNU make
578 under a name other than `make' (i.e., ``make binprefix=g install''
579 installs GNU make as `gmake').
581 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
582 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
585 * The exit status of Make when it runs into errors is now 2 instead of 1.
586 The exit status is 1 only when using -q and some target is not up to date.
587 (This change was made to comply with POSIX.2.)
591 * It is no longer a fatal error to have a NUL character in a makefile.
592 You should never put a NUL in a makefile because it can have strange
593 results, but otherwise empty lines full of NULs (such as produced by
594 the `xmkmf' program) will always work fine.
596 * The error messages for nonexistent included makefiles now refer to the
597 makefile name and line number where the `include' appeared, so Emacs's
598 C-x ` command takes you there (in case it's a typo you need to fix).
602 * Implicit rule search for archive member references is now done in the
603 opposite order from previous versions: the whole target name `LIB(MEM)'
604 first, and just the member name and parentheses `(MEM)' second.
606 * Make now gives an error for an unterminated variable or function reference.
607 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
609 * The new default variable `MAKE_VERSION' gives the version number of
610 Make, and a string describing the remote job support compiled in (if any).
611 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
613 * Commands in an invocation of the `shell' function are no longer run
614 with a modified environment like recipes are. As in versions before
615 3.68, they now run with the environment that `make' started with. We
616 have reversed the change made in version 3.68 because it turned out to
617 cause a paradoxical situation in cases like:
619 export variable = $(shell echo value)
621 When Make attempted to put this variable in the environment for a
622 recipe, it would try expand the value by running the shell command
623 `echo value'. In version 3.68, because it constructed an environment
624 for that shell command in the same way, Make would begin to go into an
625 infinite loop and then get a fatal error when it detected the loop.
627 * The recipe given for `.DEFAULT' is now used for phony targets with no
632 * You can list several archive member names inside parenthesis:
633 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
635 * You can use wildcards inside archive member references. For example,
636 `lib(*.o)' expands to all existing members of `lib' whose names end in
637 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
638 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
639 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
641 * A suffix rule `.X.a' now produces two pattern rules:
642 (%.o): %.X # Previous versions produced only this.
643 %.a: %.X # Now produces this as well, just like other suffixes.
645 * The new flag `--warn-undefined-variables' says to issue a warning message
646 whenever Make expands a reference to an undefined variable.
648 * The new `-include' directive is just like `include' except that there is
649 no error (not even a warning) for a nonexistent makefile.
651 * Commands in an invocation of the `shell' function are now run with a
652 modified environment like recipes are, so you can use `export' et al
653 to set up variables for them. They used to run with the environment
654 that `make' started with.
658 * `make --version' (or `make -v') now exits immediately after printing
663 * Make now supports long-named members in `ar' archive files.
667 * Make now supports the `+=' syntax for a variable definition which appends
668 to the variable's previous value. See the section `Appending More Text
669 to Variables' in the manual for full details.
671 * The new option `--no-print-directory' inhibits the `-w' or
672 `--print-directory' feature. Make turns on `--print-directory'
673 automatically if you use `-C' or `--directory', and in sub-makes; some
674 users have found this behavior undesirable.
676 * The built-in implicit rules now support the alternative extension
677 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
681 * Make now uses a standard GNU `configure' script. See the new file
682 INSTALL for the new (and much simpler) installation procedure.
684 * There is now a shell script to build Make the first time, if you have no
685 other `make' program. `build.sh' is created by `configure'; see README.
687 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
689 * Elements of the `$^' and `$?' automatic variables that are archive
690 member references now list only the member name, as in Unix and POSIX.2.
692 * You should no longer ever need to specify the `-w' switch, which prints
693 the current directory before and after Make runs. The `-C' switch to
694 change directory, and recursive use of Make, now set `-w' automatically.
696 * Multiple double-colon rules for the same target will no longer have their
697 recipes run simultaneously under -j, as this could result in the two
698 recipes trying to change the file at the same time and interfering with
701 * The `SHELL' variable is now never taken from the environment.
702 Each makefile that wants a shell other than the default (/bin/sh) must
703 set SHELL itself. SHELL is always exported to child processes.
704 This change was made for compatibility with POSIX.2.
706 * Make now accepts long options. There is now an informative usage message
707 that tells you what all the options are and what they do. Try `make --help'.
709 * There are two new directives: `export' and `unexport'. All variables are
710 no longer automatically put into the environments of the recipe lines that
711 Make runs. Instead, only variables specified on the command line or in
712 the environment are exported by default. To export others, use:
714 or you can define variables with:
715 export VARIABLE = VALUE
717 export VARIABLE := VALUE
721 .EXPORT_ALL_VARIABLES:
722 to get the old behavior. See the node `Variables/Recursion' in the manual
723 for a full description.
725 * The recipe from the `.DEFAULT' special target is only applied to
726 targets which have no rules at all, not all targets with no recipe.
727 This change was made for compatibility with Unix make.
729 * All fatal error messages now contain `***', so they are easy to find in
732 * Dependency file names like `-lNAME' are now replaced with the actual file
733 name found, as with files found by normal directory search (VPATH).
734 The library file `libNAME.a' may now be found in the current directory,
735 which is checked before VPATH; the standard set of directories (/lib,
736 /usr/lib, /usr/local/lib) is now checked last.
737 See the node `Libraries/Search' in the manual for full details.
739 * A single `include' directive can now specify more than one makefile to
742 You can also use shell file name patterns in an `include' directive:
745 * The default directories to search for included makefiles, and for
746 libraries specified with `-lNAME', are now set by configuration.
748 * You can now use blanks as well as colons to separate the directories in a
749 search path for the `vpath' directive or the `VPATH' variable.
751 * You can now use variables and functions in the left hand side of a
752 variable assignment, as in "$(foo)bar = value".
754 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
755 The `MAKE_COMMAND' variable is now defined to the name with which make
758 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
759 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
760 problems with shells that cannot have `+' in environment variable names.
762 * The value of a recursively expanded variable is now expanded when putting
763 it into the environment for child processes. This change was made for
764 compatibility with Unix make.
766 * A rule with no targets before the `:' is now accepted and ignored.
767 This change was made for compatibility with SunOS 4 make.
768 We do not recommend that you write your makefiles to take advantage of this.
770 * The `-I' switch can now be used in MAKEFLAGS, and are put there
771 automatically just like other switches.
775 * Built-in rules for C++ source files with the `.C' suffix.
776 We still recommend that you use `.cc' instead.
778 * If a recipe is given too many times for a single target, the last one
779 given is used, and a warning message is printed.
781 * Error messages about makefiles are in standard GNU error format,
782 so C-x ` in Emacs works on them.
784 * Dependencies of pattern rules which contain no % need not actually exist
785 if they can be created (just like dependencies which do have a %).
789 * A message is always printed when Make decides there is nothing to be done.
790 It used to be that no message was printed for top-level phony targets
791 (because "`phony' is up to date" isn't quite right). Now a different
792 message "Nothing to be done for `phony'" is printed in that case.
794 * Archives on AIX now supposedly work.
796 * When the recipes specified for .DEFAULT are used to update a target,
797 the $< automatic variable is given the same value as $@ for that target.
798 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
802 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
803 variables while remaking makefiles, so recursive makes done while remaking
804 makefiles will behave properly.
806 * If the special target `.NOEXPORT' is specified in a makefile,
807 only variables that came from the environment and variables
808 defined on the command line are exported.
812 * Suffix rules may have dependencies (which are ignored).
816 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
817 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
821 * There is now a Unix man page for GNU Make. It is certainly not a
822 replacement for the Texinfo manual, but it documents the basic
823 functionality and the switches. For full documentation, you should
824 still read the Texinfo manual. Thanks to Dennis Morse of Stanford
825 University for contributing the initial version of this.
827 * Variables which are defined by default (e.g., `CC') will no longer be
828 put into the environment for child processes. (If these variables are
829 reset by the environment, makefiles, or the command line, they will
830 still go into the environment.)
832 * Makefiles which have recipes but no dependencies (and thus are always
833 considered out of date and in need of remaking), will not be remade (if they
834 were being remade only because they were makefiles). This means that GNU
835 Make will no longer go into an infinite loop when fed the makefiles that
836 `imake' (necessary to build X Windows) produces.
838 * There is no longer a warning for using the `vpath' directive with an explicit
839 pathname (instead of a `%' pattern).
843 * When removing intermediate files, only one `rm' command line is printed,
844 listing all file names.
846 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
847 These are the directory-only and file-only versions of `$^' and `$?'.
849 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
850 directory if it exists.
852 * The automatic variable `$($/)' is no longer defined.
854 * Leading `+' characters on a recipe line make that line be executed even
855 under -n, -t, or -q (as if the line contained `$(MAKE)').
857 * For recipe lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
858 only those lines are executed, not the entire recipe.
859 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
863 * Filenames in rules will now have ~ and ~USER expanded.
865 * The `-p' output has been changed so it can be used as a makefile.
866 (All information that isn't specified by makefiles is prefaced with comment
871 * The % character can be quoted with backslash in implicit pattern rules,
872 static pattern rules, `vpath' directives, and `patsubst', `filter', and
873 `filter-out' functions. A warning is issued if a `vpath' directive's
874 pattern contains no %.
876 * The `wildcard' variable expansion function now expands ~ and ~USER.
878 * Messages indicating failed recipe lines now contain the target name:
879 make: *** [target] Error 1
881 * The `-p' output format has been changed somewhat to look more like
882 makefile rules and to give all information that Make has about files.
888 * The `-l' switch with no argument removes any previous load-average limit.
890 * When the `-w' switch is in effect, and Make has updated makefiles,
891 it will write a `Leaving directory' message before re-executing itself.
892 This makes the `directory change tracking' changes to Emacs's compilation
893 commands work properly.
897 * The automatic variable `$*' is now defined for explicit rules,
898 as it is in Unix make.
902 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
903 specified without an argument (indicating infinite jobs).
904 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
906 * Make no longer checks hashed directories after running recipes.
907 The behavior implemented in 3.41 caused too much slowdown.
911 * A dependency is NOT considered newer than its dependent if
912 they have the same modification time. The behavior implemented
913 in 3.43 conflicts with RCS.
917 * Dependency loops are no longer fatal errors.
919 * A dependency is considered newer than its dependent if
920 they have the same modification time.
924 * The variables F77 and F77FLAGS are now set by default to $(FC) and
925 $(FFLAGS). Makefiles designed for System V make may use these variables in
926 explicit rules and expect them to be set. Unfortunately, there is no way to
927 make setting these affect the Fortran implicit rules unless FC and FFLAGS
928 are not used (and these are used by BSD make).
932 * Make now checks to see if its hashed directories are changed by recipes.
933 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
937 * The `shell' function no longer captures standard error output.
941 * A file beginning with a dot can be the default target if it also contains
942 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
946 * Archive member names are truncated to 15 characters.
948 * Yet more USG stuff.
950 * Minimal support for Microport System V (a 16-bit machine and a
951 brain-damaged compiler). This has even lower priority than other USG
952 support, so if it gets beyond trivial, I will take it out completely.
954 * Revamped default implicit rules (not much visible change).
956 * The -d and -p options can come from the environment.
960 * Improved support for USG and HPUX (hopefully).
962 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
963 equivalent to `$(patsubst a,b,$(foo))'.
965 * Defining .DEFAULT with no deps or recipe clears its recipe.
967 * New default implicit rules for .S (cpp, then as), and .sh (copy and
968 make executable). All default implicit rules that use cpp (even
969 indirectly), use $(CPPFLAGS).
973 * Giving the -j option with no arguments gives you infinite jobs.
977 * New option: "-l LOAD" says not to start any new jobs while others are
978 running if the load average is not below LOAD (a floating-point number).
980 * There is support in place for implementations of remote command execution
981 in Make. See the file remote.c.
985 * No more than 10 directories will be kept open at once.
986 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
990 * Archive files will have their modification times recorded before doing
991 anything that might change their modification times by updating an archive
996 * The `MAKELEVEL' variable is defined for use by makefiles.
1000 * The recursion level indications in error messages are much shorter than
1001 they were in version 3.14.
1005 * Leading spaces before directives are ignored (as documented).
1007 * Included makefiles can determine the default goal target.
1008 (System V Make does it this way, so we are being compatible).
1012 * Variables that are defaults built into Make will not be put in the
1013 environment for children. This just saves some environment space and,
1014 except under -e, will be transparent to sub-makes.
1016 * Error messages from sub-makes will indicate the level of recursion.
1018 * Hopefully some speed-up for large directories due to a change in the
1019 directory hashing scheme.
1021 * One child will always get a standard input that is usable.
1023 * Default makefiles that don't exist will be remade and read in.
1027 * Count parentheses inside expansion function calls so you can
1028 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
1032 * Several bug fixes, including USG and Sun386i support.
1034 * `shell' function to expand shell commands a la `
1036 * If the `-d' flag is given, version information will be printed.
1038 * The `-c' option has been renamed to `-C' for compatibility with tar.
1040 * The `-p' option no longer inhibits other normal operation.
1042 * Makefiles will be updated and re-read if necessary.
1044 * Can now run several recipes at once (parallelism), -j option.
1046 * Error messages will contain the level of Make recursion, if any.
1048 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
1051 * A double-colon rule with no dependencies will always have its recipe run.
1052 (This is how both the BSD and System V versions of Make do it.)
1056 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
1058 -------------------------------------------------------------------------------
1059 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1060 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free
1061 Software Foundation, Inc. This file is part of GNU Make.
1063 GNU Make is free software; you can redistribute it and/or modify it under the
1064 terms of the GNU General Public License as published by the Free Software
1065 Foundation; either version 3 of the License, or (at your option) any later
1068 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1069 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1070 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1072 You should have received a copy of the GNU General Public License along with
1073 this program. If not, see <http://www.gnu.org/licenses/>.