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.
20 * GNU make is ported to OS/2.
22 * GNU make is ported to MinGW. The MinGW build is only supported by
23 the build_w32.bat batch file; see the file README.W32 for more
26 * WARNING: Future backward-incompatibility!
27 Up to and including this release, the '$?' variable does not contain
28 any prerequisite that does not exist, even though that prerequisite
29 might have caused the target to rebuild. Starting with the _next_
30 release of GNU make, '$?' will contain all prerequisites that caused
31 the target to be considered out of date. See this Savannah bug:
32 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
34 * WARNING: Backward-incompatibility!
35 GNU make now implements a generic "second expansion" feature on the
36 prerequisites of both explicit and implicit (pattern) rules. In order
37 to enable this feature, the special target '.SECONDEXPANSION' must be
38 defined before the first target which takes advantage of it. If this
39 feature is enabled then after all rules have been parsed the
40 prerequisites are expanded again, this time with all the automatic
41 variables in scope. This means that in addition to using standard
42 SysV $$@ in prerequisites lists, you can also use complex functions
43 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
44 as well, where the second expansion occurs when the rule is matched.
45 However, this means that when '.SECONDEXPANSION' is enabled you must
46 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
47 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
48 which used to be available by default, is now ONLY available when the
49 .SECONDEXPANSION target is defined. If your makefiles take advantage
50 of this SysV feature you will need to update them.
52 * WARNING: Backward-incompatibility!
53 In order to comply with POSIX, the way in which GNU make processes
54 backslash-newline sequences in command strings has changed. If your
55 makefiles use backslash-newline sequences inside of single-quoted
56 strings in command scripts you will be impacted by this change. See
57 the GNU make manual subsection "Splitting Command Lines" (node
58 "Splitting Lines"), in section "Command Syntax", chapter "Writing the
59 Commands in Rules", for details.
61 * WARNING: Backward-incompatibility!
62 Some previous versions of GNU make had a bug where "#" in a function
63 invocation such as $(shell ...) was treated as a make comment. A
64 workaround was to escape these with backslashes. This bug has been
65 fixed: if your makefile uses "\#" in a function invocation the
66 backslash is now preserved, so you'll need to remove it.
68 * New command-line option: -L (--check-symlink-times). On systems that
69 support symbolic links, if this option is given then GNU make will
70 use the most recent modification time of any symbolic links that are
71 used to resolve target files. The default behavior remains as it
72 always has: use the modification time of the actual target file only.
74 * The "else" conditional line can now be followed by any other valid
75 conditional on the same line: this does not increase the depth of the
76 conditional nesting, so only one "endif" is required to close the
79 * All pattern-specific variables that match a given target are now used
80 (previously only the first match was used).
82 * Target-specific variables can be marked as exportable using the
85 * In a recursive $(call ...) context, any extra arguments from the outer
86 call are now masked in the context of the inner call.
88 * Implemented a solution for the "thundering herd" problem with "-j -l".
89 This version of GNU make uses an algorithm suggested by Thomas Riedl
90 <thomas.riedl@siemens.com> to track the number of jobs started in the
91 last second and artificially adjust GNU make's view of the system's
92 load average accordingly.
94 * New special variables available in this release:
95 - .INCLUDE_DIRS: Expands to a list of directories that make searches
96 for included makefiles.
97 - .FEATURES: Contains a list of special features available in this
99 - .DEFAULT_GOAL: Set the name of the default goal make will
100 use if no goals are provided on the command line.
101 - MAKE_RESTARTS: If set, then this is the number of times this
102 instance of make has been restarted (see "How Makefiles Are Remade"
104 - New automatic variable: $| (added in 3.80, actually): contains all
105 the order-only prerequisites defined for the target.
107 * New functions available in this release:
108 - $(lastword ...) returns the last word in the list. This gives
109 identical results as $(word $(words ...) ...), but is much faster.
110 - $(abspath ...) returns the absolute path (all "." and ".."
111 directories resolved, and any duplicate "/" characters removed) for
113 - $(realpath ...) returns the canonical pathname for each path
114 provided. The canonical pathname is the absolute pathname, with
115 all symbolic links resolved as well.
116 - $(info ...) prints its arguments to stdout. No makefile name or
117 line number info, etc. is printed.
118 - $(flavor ...) returns the flavor of a variable.
119 - $(or ...) provides a short-circuiting OR conditional: each argument
120 is expanded. The first true (non-empty) argument is returned; no
121 further arguments are expanded. Expands to empty if there are no
123 - $(and ...) provides a short-circuiting AND conditional: each
124 argument is expanded. The first false (empty) argument is
125 returned; no further arguments are expanded. Expands to the last
126 argument if all arguments are true.
128 * Changes made for POSIX compatibility:
129 - Only touch targets (under -t) if they have at least one command.
130 - Setting the SHELL make variable does NOT change the value of the
131 SHELL environment variable given to programs invoked by make. As
132 an enhancement to POSIX, if you export the make variable SHELL then
133 it will be set in the environment, just as before.
135 * On MS Windows systems, explicitly setting SHELL to a pathname ending
136 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
137 the DOS command interpreter in batch mode even if a UNIX-like shell
138 could be found on the system.
140 * On VMS there is now support for case-sensitive filesystems such as ODS5.
141 See the readme.vms file for information.
143 * Parallel builds (-jN) no longer require a working Bourne shell on
144 Windows platforms. They work even with the stock Windows shells, such
145 as cmd.exe and command.com.
147 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
148 should not be impacted.
150 * New translations for Swedish, Chinese (simplified), Ukrainian,
151 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
154 A complete list of bugs fixed in this version is available here:
156 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
161 * A new feature exists: order-only prerequisites. These prerequisites
162 affect the order in which targets are built, but they do not impact
163 the rebuild/no-rebuild decision of their dependents. That is to say,
164 they allow you to require target B be built before target A, without
165 requiring that target A will always be rebuilt if target B is updated.
166 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
168 * For compatibility with SysV make, GNU make now supports the peculiar
169 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
170 This syntax is only valid within explicit and static pattern rules: it
171 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
172 <egp@free.fr> provided a patch implementing this feature; however, I
173 decided to implement it in a different way.
175 * The argument to the "ifdef" conditional is now expanded before it's
176 tested, so it can be a constructed variable name.
178 Similarly, the arguments to "export" (when not used in a variable
179 definition context) and "unexport" are also now expanded.
181 * A new function is defined: $(value ...). The argument to this
182 function is the _name_ of a variable. The result of the function is
183 the value of the variable, without having been expanded.
185 * A new function is defined: $(eval ...). The arguments to this
186 function should expand to makefile commands, which will then be
187 evaluated as if they had appeared in the makefile. In combination
188 with define/endef multiline variable definitions this is an extremely
189 powerful capability. The $(value ...) function is also sometimes
192 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
193 list of each makefile GNU make has read, or started to read, in the
194 order in which they were encountered. So, the last filename in the
195 list when a makefile is just being read (before any includes) is the
196 name of the current makefile.
198 * A new built-in variable is defined: $(.VARIABLES). When it is
199 expanded it returns a complete list of variable names defined by all
200 makefiles at that moment.
202 * A new command-line option is defined, -B or --always-make. If
203 specified GNU make will consider all targets out-of-date even if they
204 would otherwise not be.
206 * The arguments to $(call ...) functions were being stored in $1, $2,
207 etc. as recursive variables, even though they are fully expanded
208 before assignment. This means that escaped dollar signs ($$ etc.)
209 were not behaving properly. Now the arguments are stored as simple
210 variables. This may mean that if you added extra escaping to your
211 $(call ...) function arguments you will need to undo it now.
213 * The variable invoked by $(call ...) can now be recursive: unlike other
214 variables it can reference itself and this will not produce an error
215 when it is used as the first argument to $(call ...) (but only then).
217 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
218 option --disable-nsec-timestamps. You might need this if your build
219 process depends on tools like "cp -p" preserving time stamps, since
220 "cp -p" (right now) doesn't preserve the subsecond portion of a time
223 * Updated translations for French, Galician, German, Japanese, Korean,
224 and Russian. New translations for Croatian, Danish, Hebrew, and
227 * Updated internationalization support to Gettext 0.11.5.
228 GNU make now uses Gettext's "external" feature, and does not include
229 any internationalization code itself. Configure will search your
230 system for an existing implementation of GNU Gettext (only GNU Gettext
231 is acceptable) and use it if it exists. If not, NLS will be disabled.
232 See ABOUT-NLS for more information.
234 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
236 A complete list of bugs fixed in this version is available here:
238 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
243 * .SECONDARY with no prerequisites now prevents any target from being
244 removed because make thinks it's an intermediate file, not just those
245 listed in the makefile.
247 * New configure option --disable-nsec-timestamps, but this was
248 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
252 * GNU make optionally supports internationalization and locales via the
253 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
254 file for more information on configuring GNU make for NLS.
256 * Previously, GNU make quoted variables such as MAKEFLAGS and
257 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
258 be used within make build scripts. However, using them there is not
259 proper behavior: they are meant to be passed to subshells via the
260 environment. Unfortunately the values were not quoted properly to be
261 passed through the environment. This meant that make didn't properly
262 pass some types of command line values to submakes.
264 With this version we change that behavior: now these variables are
265 quoted properly for passing through the environment, which is the
266 correct way to do it. If you previously used these variables
267 explicitly within a make rule you may need to re-examine your use for
268 correctness given this change.
270 * A new pseudo-target .NOTPARALLEL is available. If defined, the
271 current makefile is run serially regardless of the value of -j.
272 However, submakes are still eligible for parallel execution.
274 * The --debug option has changed: it now allows optional flags
275 controlling the amount and type of debugging output. By default only
276 a minimal amount information is generated, displaying the names of
277 "normal" targets (not makefiles) that were deemed out of date and in
278 need of being rebuilt.
280 Note that the -d option behaves as before: it takes no arguments and
281 all debugging information is generated.
283 * The `-p' (print database) output now includes filename and linenumber
284 information for variable definitions, to aid debugging.
286 * The wordlist function no longer reverses its arguments if the "start"
287 value is greater than the "end" value. If that's true, nothing is
290 * Hartmut Becker provided many updates for the VMS port of GNU make.
291 See the readme.vms file for more details.
295 * Two new functions, $(error ...) and $(warning ...) are available. The
296 former will cause make to fail and exit immediately upon expansion of
297 the function, with the text provided as the error message. The latter
298 causes the text provided to be printed as a warning message, but make
301 * A new function $(call ...) is available. This allows users to create
302 their own parameterized macros and invoke them later. Original
303 implementation of this function was provided by Han-Wen Nienhuys
306 * A new function $(if ...) is available. It provides if-then-else
307 capabilities in a builtin function. Original implementation of this
308 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
310 * Make defines a new variable, .LIBPATTERNS. This variable controls how
311 library dependency expansion (dependencies like ``-lfoo'') is performed.
313 * Make accepts CRLF sequences as well as traditional LF, for
314 compatibility with makefiles created on other operating systems.
316 * Make accepts a new option: -R, or --no-builtin-variables. This option
317 disables the definition of the rule-specific builtin variables (CC,
318 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
321 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
323 On systems that support POSIX pipe(2) semantics, GNU make can now pass
324 -jN options to submakes rather than forcing them all to use -j1. The
325 top make and all its sub-make processes use a pipe to communicate with
326 each other to ensure that no more than N jobs are started across all
327 makes. To get the old behavior of -j back, you can configure make
328 with the --disable-job-server option.
330 * The confusing term "dependency" has been replaced by the more accurate
331 and standard term "prerequisite", both in the manual and in all GNU make
334 * GNU make supports the "big archive" library format introduced in AIX 4.3.
336 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
337 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
338 support for Solaris and Linux was introduced in 3.77, but the
339 configuration had issues: these have also been resolved).
341 * The Windows 95/98/NT (W32) version of GNU make now has native support
342 for the Cygnus Cygwin release B20.1 shell (bash).
344 * The GNU make regression test suite, long available separately "under
345 the table", has been integrated into the release. You can invoke it
346 by running "make check" in the distribution. Note that it requires
347 Perl (either Perl 4 or Perl 5) to run.
351 * Implement BSD make's "?=" variable assignment operator. The variable
352 is assigned the specified value only if that variable is not already
355 * Make defines a new variable, "CURDIR", to contain the current working
356 directory (after the -C option, if any, has been processed).
357 Modifying this variable has no effect on the operation of make.
359 * Make defines a new default RCS rule, for new-style master file
360 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
362 Make defines new default rules for DOS-style C++ file naming
363 conventions, with ``.cpp'' suffixes. All the same rules as for
364 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
365 COMPILE.cpp macros (which default to the same value as LINK.cc and
366 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
367 use CXXFLAGS to change C++ compiler flags.
369 * A new feature, "target-specific variable values", has been added.
370 This is a large change so please see the appropriate sections of the
371 manual for full details. Briefly, syntax like this:
373 TARGET: VARIABLE = VALUE
375 defines VARIABLE as VALUE within the context of TARGET. This is
376 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
377 that the assignment may be of any type, not just recursive, and that
378 the override keyword is available.
380 COMPATIBILITY: This new syntax means that if you have any rules where
381 the first or second dependency has an equal sign (=) in its name,
382 you'll have to escape them with a backslash: "foo : bar\=baz".
383 Further, if you have any dependencies which already contain "\=",
384 you'll have to escape both of them: "foo : bar\\\=baz".
386 * A new appendix listing the most common error and warning messages
387 generated by GNU make, with some explanation, has been added to the
388 GNU make User's Manual.
390 * Updates to the GNU make Customs library support (see README.customs).
392 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
393 and to the DOS port from Eli Zaretski (see README.DOS).
397 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
401 * GNU make now uses automake to control Makefile.in generation. This
402 should make it more consistent with the GNU standards.
404 * VPATH functionality has been changed to incorporate the VPATH+ patch,
405 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
408 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
409 were specified on the command line, if any. Modifying this variable
410 has no effect on the operation of make.
412 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
413 list of words from number S to number E (inclusive) of TEXT.
415 * Instead of an error, detection of future modification times gives a
416 warning and continues. The warning is repeated just before GNU make
417 exits, so it is less likely to be lost.
419 * Fix the $(basename) and $(suffix) functions so they only operate on
420 the last filename, not the entire string:
422 Command Old Result New Result
423 ------- ---------- ----------
425 $(basename a.b/c) a a.b/c
427 $(suffix a.b/c) b/c <empty>
429 * The $(strip) function now removes newlines as well as TABs and spaces.
431 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
434 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
436 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
437 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
438 and utilities. See README.DOS for details, and direct all questions
439 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
440 Delorie <dj@delorie.com>.
442 * John W. Eaton has updated the VMS port to support libraries and VPATH.
446 * The directory messages printed by `-w' and implicitly in sub-makes,
447 are now omitted if Make runs no commands and has no other messages to print.
449 * Make now detects files that for whatever reason have modification times
450 in the future and gives an error. Files with such impossible timestamps
451 can result from unsynchronized clocks, or archived distributions
452 containing bogus timestamps; they confuse Make's dependency engine
455 * The new directive `sinclude' is now recognized as another name for
456 `-include', for compatibility with some other Makes.
458 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
459 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
461 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
462 See README.W32 for details, and direct all Windows-related questions to
463 <rob_tulloh@tivoli.com>.
467 * Converted to use Autoconf version 2, so `configure' has some new options.
468 See INSTALL for details.
470 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
471 output enabled by -d, at any time during the run.
475 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
476 He is maintaining the DOS port, not the GNU Make maintainer;
477 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
478 MS-DOS binaries are available for FTP from ftp.simtel.net in
479 /pub/simtelnet/gnu/djgpp/.
481 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
482 contain variable definitions itself; these are treated just like
483 command-line variable definitions. Make will automatically insert any
484 variable definitions from the environment value of `MAKEFLAGS' or from
485 the command line, into the `MAKEFLAGS' value exported to children. The
486 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
487 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
488 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
489 in the environment when its size is limited.
491 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
492 a rule if it has changed when its commands exit with a nonzero status,
493 just as when the commands get a signal.
495 * The automatic variable `$+' is new. It lists all the dependencies like
496 `$^', but preserves duplicates listed in the makefile. This is useful
497 for linking rules, where library files sometimes need to be listed twice
500 * You can now specify the `.IGNORE' and `.SILENT' special targets with
501 dependencies to limit their effects to those files. If a file appears as
502 a dependency of `.IGNORE', then errors will be ignored while running the
503 commands to update that file. Likewise if a file appears as a dependency
504 of `.SILENT', then the commands to update that file will not be printed
505 before they are run. (This change was made to conform to POSIX.2.)
509 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
510 `$(^D)' now omit the trailing slash from the directory name. (This change
511 was made to comply with POSIX.2.)
513 * The source distribution now includes the Info files for the Make manual.
514 There is no longer a separate distribution containing Info and DVI files.
516 * You can now set the variables `binprefix' and/or `manprefix' in
517 Makefile.in (or on the command line when installing) to install GNU make
518 under a name other than `make' (i.e., ``make binprefix=g install''
519 installs GNU make as `gmake').
521 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
522 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
525 * The exit status of Make when it runs into errors is now 2 instead of 1.
526 The exit status is 1 only when using -q and some target is not up to date.
527 (This change was made to comply with POSIX.2.)
531 * It is no longer a fatal error to have a NUL character in a makefile.
532 You should never put a NUL in a makefile because it can have strange
533 results, but otherwise empty lines full of NULs (such as produced by
534 the `xmkmf' program) will always work fine.
536 * The error messages for nonexistent included makefiles now refer to the
537 makefile name and line number where the `include' appeared, so Emacs's
538 C-x ` command takes you there (in case it's a typo you need to fix).
542 * Implicit rule search for archive member references is now done in the
543 opposite order from previous versions: the whole target name `LIB(MEM)'
544 first, and just the member name and parentheses `(MEM)' second.
546 * Make now gives an error for an unterminated variable or function reference.
547 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
549 * The new default variable `MAKE_VERSION' gives the version number of
550 Make, and a string describing the remote job support compiled in (if any).
551 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
553 * Commands in an invocation of the `shell' function are no longer run with
554 a modified environment like target commands are. As in versions before
555 3.68, they now run with the environment that `make' started with. We
556 have reversed the change made in version 3.68 because it turned out to
557 cause a paradoxical situation in cases like:
559 export variable = $(shell echo value)
561 When Make attempted to put this variable in the environment for a target
562 command, it would try expand the value by running the shell command
563 `echo value'. In version 3.68, because it constructed an environment
564 for that shell command in the same way, Make would begin to go into an
565 infinite loop and then get a fatal error when it detected the loop.
567 * The commands given for `.DEFAULT' are now used for phony targets with no
572 * You can list several archive member names inside parenthesis:
573 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
575 * You can use wildcards inside archive member references. For example,
576 `lib(*.o)' expands to all existing members of `lib' whose names end in
577 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
578 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
579 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
581 * A suffix rule `.X.a' now produces two pattern rules:
582 (%.o): %.X # Previous versions produced only this.
583 %.a: %.X # Now produces this as well, just like other suffixes.
585 * The new flag `--warn-undefined-variables' says to issue a warning message
586 whenever Make expands a reference to an undefined variable.
588 * The new `-include' directive is just like `include' except that there is
589 no error (not even a warning) for a nonexistent makefile.
591 * Commands in an invocation of the `shell' function are now run with a
592 modified environment like target commands are, so you can use `export' et
593 al to set up variables for them. They used to run with the environment
594 that `make' started with.
598 * `make --version' (or `make -v') now exits immediately after printing
603 * Make now supports long-named members in `ar' archive files.
607 * Make now supports the `+=' syntax for a variable definition which appends
608 to the variable's previous value. See the section `Appending More Text
609 to Variables' in the manual for full details.
611 * The new option `--no-print-directory' inhibits the `-w' or
612 `--print-directory' feature. Make turns on `--print-directory'
613 automatically if you use `-C' or `--directory', and in sub-makes; some
614 users have found this behavior undesirable.
616 * The built-in implicit rules now support the alternative extension
617 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
621 * Make now uses a standard GNU `configure' script. See the new file
622 INSTALL for the new (and much simpler) installation procedure.
624 * There is now a shell script to build Make the first time, if you have no
625 other `make' program. `build.sh' is created by `configure'; see README.
627 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
629 * Elements of the `$^' and `$?' automatic variables that are archive
630 member references now list only the member name, as in Unix and POSIX.2.
632 * You should no longer ever need to specify the `-w' switch, which prints
633 the current directory before and after Make runs. The `-C' switch to
634 change directory, and recursive use of Make, now set `-w' automatically.
636 * Multiple double-colon rules for the same target will no longer have their
637 commands run simultaneously under -j, as this could result in the two
638 commands trying to change the file at the same time and interfering with
641 * The `SHELL' variable is now never taken from the environment.
642 Each makefile that wants a shell other than the default (/bin/sh) must
643 set SHELL itself. SHELL is always exported to child processes.
644 This change was made for compatibility with POSIX.2.
646 * Make now accepts long options. There is now an informative usage message
647 that tells you what all the options are and what they do. Try `make --help'.
649 * There are two new directives: `export' and `unexport'. All variables are
650 no longer automatically put into the environments of the commands that
651 Make runs. Instead, only variables specified on the command line or in
652 the environment are exported by default. To export others, use:
654 or you can define variables with:
655 export VARIABLE = VALUE
657 export VARIABLE := VALUE
661 .EXPORT_ALL_VARIABLES:
662 to get the old behavior. See the node `Variables/Recursion' in the manual
663 for a full description.
665 * The commands from the `.DEFAULT' special target are only applied to
666 targets which have no rules at all, not all targets with no commands.
667 This change was made for compatibility with Unix make.
669 * All fatal error messages now contain `***', so they are easy to find in
672 * Dependency file names like `-lNAME' are now replaced with the actual file
673 name found, as with files found by normal directory search (VPATH).
674 The library file `libNAME.a' may now be found in the current directory,
675 which is checked before VPATH; the standard set of directories (/lib,
676 /usr/lib, /usr/local/lib) is now checked last.
677 See the node `Libraries/Search' in the manual for full details.
679 * A single `include' directive can now specify more than one makefile to
682 You can also use shell file name patterns in an `include' directive:
685 * The default directories to search for included makefiles, and for
686 libraries specified with `-lNAME', are now set by configuration.
688 * You can now use blanks as well as colons to separate the directories in a
689 search path for the `vpath' directive or the `VPATH' variable.
691 * You can now use variables and functions in the left hand side of a
692 variable assignment, as in "$(foo)bar = value".
694 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
695 The `MAKE_COMMAND' variable is now defined to the name with which make
698 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
699 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
700 problems with shells that cannot have `+' in environment variable names.
702 * The value of a recursively expanded variable is now expanded when putting
703 it into the environment for child processes. This change was made for
704 compatibility with Unix make.
706 * A rule with no targets before the `:' is now accepted and ignored.
707 This change was made for compatibility with SunOS 4 make.
708 We do not recommend that you write your makefiles to take advantage of this.
710 * The `-I' switch can now be used in MAKEFLAGS, and are put there
711 automatically just like other switches.
715 * Built-in rules for C++ source files with the `.C' suffix.
716 We still recommend that you use `.cc' instead.
718 * If commands are given too many times for a single target,
719 the last set given is used, and a warning message is printed.
721 * Error messages about makefiles are in standard GNU error format,
722 so C-x ` in Emacs works on them.
724 * Dependencies of pattern rules which contain no % need not actually exist
725 if they can be created (just like dependencies which do have a %).
729 * A message is always printed when Make decides there is nothing to be done.
730 It used to be that no message was printed for top-level phony targets
731 (because "`phony' is up to date" isn't quite right). Now a different
732 message "Nothing to be done for `phony'" is printed in that case.
734 * Archives on AIX now supposedly work.
736 * When the commands specified for .DEFAULT are used to update a target,
737 the $< automatic variable is given the same value as $@ for that target.
738 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
742 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
743 variables while remaking makefiles, so recursive makes done while remaking
744 makefiles will behave properly.
746 * If the special target `.NOEXPORT' is specified in a makefile,
747 only variables that came from the environment and variables
748 defined on the command line are exported.
752 * Suffix rules may have dependencies (which are ignored).
756 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
757 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
761 * There is now a Unix man page for GNU Make. It is certainly not a replacement
762 for the Texinfo manual, but it documents the basic functionality and the
763 switches. For full documentation, you should still read the Texinfo manual.
764 Thanks to Dennis Morse of Stanford University for contributing the initial
767 * Variables which are defined by default (e.g., `CC') will no longer be put
768 into the environment for child processes. (If these variables are reset by the
769 environment, makefiles, or the command line, they will still go into the
772 * Makefiles which have commands but no dependencies (and thus are always
773 considered out of date and in need of remaking), will not be remade (if they
774 were being remade only because they were makefiles). This means that GNU
775 Make will no longer go into an infinite loop when fed the makefiles that
776 `imake' (necessary to build X Windows) produces.
778 * There is no longer a warning for using the `vpath' directive with an explicit
779 pathname (instead of a `%' pattern).
783 * When removing intermediate files, only one `rm' command line is printed,
784 listing all file names.
786 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
787 These are the directory-only and file-only versions of `$^' and `$?'.
789 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
790 directory if it exists.
792 * The automatic variable `$($/)' is no longer defined.
794 * Leading `+' characters on a command line make that line be executed even
795 under -n, -t, or -q (as if the line contained `$(MAKE)').
797 * For command lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
798 only those lines are executed, not their entire rules.
799 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
803 * Filenames in rules will now have ~ and ~USER expanded.
805 * The `-p' output has been changed so it can be used as a makefile.
806 (All information that isn't specified by makefiles is prefaced with comment
811 * The % character can be quoted with backslash in implicit pattern rules,
812 static pattern rules, `vpath' directives, and `patsubst', `filter', and
813 `filter-out' functions. A warning is issued if a `vpath' directive's
814 pattern contains no %.
816 * The `wildcard' variable expansion function now expands ~ and ~USER.
818 * Messages indicating failed commands now contain the target name:
819 make: *** [target] Error 1
821 * The `-p' output format has been changed somewhat to look more like
822 makefile rules and to give all information that Make has about files.
828 * The `-l' switch with no argument removes any previous load-average limit.
830 * When the `-w' switch is in effect, and Make has updated makefiles,
831 it will write a `Leaving directory' messagfe before re-executing itself.
832 This makes the `directory change tracking' changes to Emacs's compilation
833 commands work properly.
837 * The automatic variable `$*' is now defined for explicit rules,
838 as it is in Unix make.
842 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
843 specified without an argument (indicating infinite jobs).
844 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
846 * Make no longer checks hashed directories after running commands.
847 The behavior implemented in 3.41 caused too much slowdown.
851 * A dependency is NOT considered newer than its dependent if
852 they have the same modification time. The behavior implemented
853 in 3.43 conflicts with RCS.
857 * Dependency loops are no longer fatal errors.
859 * A dependency is considered newer than its dependent if
860 they have the same modification time.
864 * The variables F77 and F77FLAGS are now set by default to $(FC) and
865 $(FFLAGS). Makefiles designed for System V make may use these variables in
866 explicit rules and expect them to be set. Unfortunately, there is no way to
867 make setting these affect the Fortran implicit rules unless FC and FFLAGS
868 are not used (and these are used by BSD make).
872 * Make now checks to see if its hashed directories are changed by commands.
873 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
877 * The `shell' function no longer captures standard error output.
881 * A file beginning with a dot can be the default target if it also contains
882 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
886 * Archive member names are truncated to 15 characters.
888 * Yet more USG stuff.
890 * Minimal support for Microport System V (a 16-bit machine and a
891 brain-damaged compiler). This has even lower priority than other USG
892 support, so if it gets beyond trivial, I will take it out completely.
894 * Revamped default implicit rules (not much visible change).
896 * The -d and -p options can come from the environment.
900 * Improved support for USG and HPUX (hopefully).
902 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
903 equivalent to `$(patsubst a,b,$(foo))'.
905 * Defining .DEFAULT with no deps or commands clears its commands.
907 * New default implicit rules for .S (cpp, then as), and .sh (copy and make
908 executable). All default implicit rules that use cpp (even indirectly), use
913 * Giving the -j option with no arguments gives you infinite jobs.
917 * New option: "-l LOAD" says not to start any new jobs while others are
918 running if the load average is not below LOAD (a floating-point number).
920 * There is support in place for implementations of remote command execution
921 in Make. See the file remote.c.
925 * No more than 10 directories will be kept open at once.
926 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
930 * Archive files will have their modification times recorded before doing
931 anything that might change their modification times by updating an archive
936 * The `MAKELEVEL' variable is defined for use by makefiles.
940 * The recursion level indications in error messages are much shorter than
941 they were in version 3.14.
945 * Leading spaces before directives are ignored (as documented).
947 * Included makefiles can determine the default goal target.
948 (System V Make does it this way, so we are being compatible).
952 * Variables that are defaults built into Make will not be put in the
953 environment for children. This just saves some environment space and,
954 except under -e, will be transparent to sub-makes.
956 * Error messages from sub-makes will indicate the level of recursion.
958 * Hopefully some speed-up for large directories due to a change in the
959 directory hashing scheme.
961 * One child will always get a standard input that is usable.
963 * Default makefiles that don't exist will be remade and read in.
967 * Count parentheses inside expansion function calls so you can
968 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
972 * Several bug fixes, including USG and Sun386i support.
974 * `shell' function to expand shell commands a la `
976 * If the `-d' flag is given, version information will be printed.
978 * The `-c' option has been renamed to `-C' for compatibility with tar.
980 * The `-p' option no longer inhibits other normal operation.
982 * Makefiles will be updated and re-read if necessary.
984 * Can now run several commands at once (parallelism), -j option.
986 * Error messages will contain the level of Make recursion, if any.
988 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
991 * A double-colon rule with no dependencies will always have its commands run.
992 (This is how both the BSD and System V versions of Make do it.)
996 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
998 -------------------------------------------------------------------------------
999 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1000 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
1002 This file is part of GNU Make.
1004 GNU Make is free software; you can redistribute it and/or modify it under the
1005 terms of the GNU General Public License as published by the Free Software
1006 Foundation; either version 2, or (at your option) any later version.
1008 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1009 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1010 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1012 You should have received a copy of the GNU General Public License along with
1013 GNU Make; see the file COPYING. If not, write to the Free Software
1014 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.