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19 be considered out of date, even if they do not exist (previously only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 * New command line option: --eval=STRING causes STRING to be evaluated as
41 makefile syntax (akin to using the $(eval ...) function). The evaluation is
42 performed after all default rules and variables are defined, but before any
45 * New special variable: .RECIPEPREFIX allows you to reset the recipe
46 introduction character from the default (TAB) to something else. The first
47 character of this variable value is the new recipe introduction character.
48 If the variable is set to the empty string, TAB is used again. It can be
49 set and reset at will; recipes will use the value active when they were
50 first parsed. To detect this feature check the value of $(.RECIPEPREFIX).
52 * New variable modifier 'private': prefixing a variable assignment with the
53 modifier 'private' suppresses inheritance of that variable by
54 prerequisites. This is most useful for target- and pattern-specific
57 * New make directive: 'undefine' allows you to undefine a variable so
58 that it appears as if it was never set. Both $(flavor) and $(origin)
59 functions will return 'undefined' for such a variable. To detect this
60 feature search for 'undefine in the .FEATURES special variable.
62 * The parser for variable assignments has been enhanced to allow multiple
63 modifiers ('export', 'override', 'private') on the same line as variables,
64 including define/endef variables, and in any order. Also, it is possible
65 to create variables and targets named as these modifiers.
70 * GNU make is ported to OS/2.
72 * GNU make is ported to MinGW. The MinGW build is only supported by
73 the build_w32.bat batch file; see the file README.W32 for more
76 * WARNING: Future backward-incompatibility!
77 Up to and including this release, the '$?' variable does not contain
78 any prerequisite that does not exist, even though that prerequisite
79 might have caused the target to rebuild. Starting with the _next_
80 release of GNU make, '$?' will contain all prerequisites that caused
81 the target to be considered out of date. See this Savannah bug:
82 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
84 * WARNING: Backward-incompatibility!
85 GNU make now implements a generic "second expansion" feature on the
86 prerequisites of both explicit and implicit (pattern) rules. In order
87 to enable this feature, the special target '.SECONDEXPANSION' must be
88 defined before the first target which takes advantage of it. If this
89 feature is enabled then after all rules have been parsed the
90 prerequisites are expanded again, this time with all the automatic
91 variables in scope. This means that in addition to using standard
92 SysV $$@ in prerequisites lists, you can also use complex functions
93 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
94 as well, where the second expansion occurs when the rule is matched.
95 However, this means that when '.SECONDEXPANSION' is enabled you must
96 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
97 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
98 which used to be available by default, is now ONLY available when the
99 .SECONDEXPANSION target is defined. If your makefiles take advantage
100 of this SysV feature you will need to update them.
102 * WARNING: Backward-incompatibility!
104 In order to comply with POSIX, the way in which GNU make processes
105 backslash-newline sequences in recipes has changed. If your makefiles
106 use backslash-newline sequences inside of single-quoted strings in
107 recipes you will be impacted by this change. See the GNU make manual
108 subsection "Splitting Recipe Lines" (node "Splitting Lines"), in
109 section "Recipe Syntax", chapter "Writing Recipe in Rules", for
112 * WARNING: Backward-incompatibility!
113 Some previous versions of GNU make had a bug where "#" in a function
114 invocation such as $(shell ...) was treated as a make comment. A
115 workaround was to escape these with backslashes. This bug has been
116 fixed: if your makefile uses "\#" in a function invocation the
117 backslash is now preserved, so you'll need to remove it.
119 * New command line option: -L (--check-symlink-times). On systems that
120 support symbolic links, if this option is given then GNU make will
121 use the most recent modification time of any symbolic links that are
122 used to resolve target files. The default behavior remains as it
123 always has: use the modification time of the actual target file only.
125 * The "else" conditional line can now be followed by any other valid
126 conditional on the same line: this does not increase the depth of the
127 conditional nesting, so only one "endif" is required to close the
130 * All pattern-specific variables that match a given target are now used
131 (previously only the first match was used).
133 * Target-specific variables can be marked as exportable using the
136 * In a recursive $(call ...) context, any extra arguments from the outer
137 call are now masked in the context of the inner call.
139 * Implemented a solution for the "thundering herd" problem with "-j -l".
140 This version of GNU make uses an algorithm suggested by Thomas Riedl
141 <thomas.riedl@siemens.com> to track the number of jobs started in the
142 last second and artificially adjust GNU make's view of the system's
143 load average accordingly.
145 * New special variables available in this release:
146 - .INCLUDE_DIRS: Expands to a list of directories that make searches
147 for included makefiles.
148 - .FEATURES: Contains a list of special features available in this
150 - .DEFAULT_GOAL: Set the name of the default goal make will
151 use if no goals are provided on the command line.
152 - MAKE_RESTARTS: If set, then this is the number of times this
153 instance of make has been restarted (see "How Makefiles Are Remade"
155 - New automatic variable: $| (added in 3.80, actually): contains all
156 the order-only prerequisites defined for the target.
158 * New functions available in this release:
159 - $(lastword ...) returns the last word in the list. This gives
160 identical results as $(word $(words ...) ...), but is much faster.
161 - $(abspath ...) returns the absolute path (all "." and ".."
162 directories resolved, and any duplicate "/" characters removed) for
164 - $(realpath ...) returns the canonical pathname for each path
165 provided. The canonical pathname is the absolute pathname, with
166 all symbolic links resolved as well.
167 - $(info ...) prints its arguments to stdout. No makefile name or
168 line number info, etc. is printed.
169 - $(flavor ...) returns the flavor of a variable.
170 - $(or ...) provides a short-circuiting OR conditional: each argument
171 is expanded. The first true (non-empty) argument is returned; no
172 further arguments are expanded. Expands to empty if there are no
174 - $(and ...) provides a short-circuiting AND conditional: each
175 argument is expanded. The first false (empty) argument is
176 returned; no further arguments are expanded. Expands to the last
177 argument if all arguments are true.
179 * Changes made for POSIX compatibility:
180 - Only touch targets (under -t) if they have a recipe.
181 - Setting the SHELL make variable does NOT change the value of the
182 SHELL environment variable given to programs invoked by make. As
183 an enhancement to POSIX, if you export the make variable SHELL then
184 it will be set in the environment, just as before.
186 * On MS Windows systems, explicitly setting SHELL to a pathname ending
187 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
188 the DOS command interpreter in batch mode even if a UNIX-like shell
189 could be found on the system.
191 * On VMS there is now support for case-sensitive filesystems such as ODS5.
192 See the readme.vms file for information.
194 * Parallel builds (-jN) no longer require a working Bourne shell on
195 Windows platforms. They work even with the stock Windows shells, such
196 as cmd.exe and command.com.
198 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
199 should not be impacted.
201 * New translations for Swedish, Chinese (simplified), Ukrainian,
202 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
205 A complete list of bugs fixed in this version is available here:
207 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
212 * A new feature exists: order-only prerequisites. These prerequisites
213 affect the order in which targets are built, but they do not impact
214 the rebuild/no-rebuild decision of their dependents. That is to say,
215 they allow you to require target B be built before target A, without
216 requiring that target A will always be rebuilt if target B is updated.
217 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
219 * For compatibility with SysV make, GNU make now supports the peculiar
220 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
221 This syntax is only valid within explicit and static pattern rules: it
222 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
223 <egp@free.fr> provided a patch implementing this feature; however, I
224 decided to implement it in a different way.
226 * The argument to the "ifdef" conditional is now expanded before it's
227 tested, so it can be a constructed variable name.
229 Similarly, the arguments to "export" (when not used in a variable
230 definition context) and "unexport" are also now expanded.
232 * A new function is defined: $(value ...). The argument to this
233 function is the _name_ of a variable. The result of the function is
234 the value of the variable, without having been expanded.
236 * A new function is defined: $(eval ...). The arguments to this
237 function should expand to makefile commands, which will then be
238 evaluated as if they had appeared in the makefile. In combination
239 with define/endef multiline variable definitions this is an extremely
240 powerful capability. The $(value ...) function is also sometimes
243 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
244 list of each makefile GNU make has read, or started to read, in the
245 order in which they were encountered. So, the last filename in the
246 list when a makefile is just being read (before any includes) is the
247 name of the current makefile.
249 * A new built-in variable is defined: $(.VARIABLES). When it is
250 expanded it returns a complete list of variable names defined by all
251 makefiles at that moment.
253 * A new command line option is defined, -B or --always-make. If
254 specified GNU make will consider all targets out-of-date even if they
255 would otherwise not be.
257 * The arguments to $(call ...) functions were being stored in $1, $2,
258 etc. as recursive variables, even though they are fully expanded
259 before assignment. This means that escaped dollar signs ($$ etc.)
260 were not behaving properly. Now the arguments are stored as simple
261 variables. This may mean that if you added extra escaping to your
262 $(call ...) function arguments you will need to undo it now.
264 * The variable invoked by $(call ...) can now be recursive: unlike other
265 variables it can reference itself and this will not produce an error
266 when it is used as the first argument to $(call ...) (but only then).
268 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
269 option --disable-nsec-timestamps. You might need this if your build
270 process depends on tools like "cp -p" preserving time stamps, since
271 "cp -p" (right now) doesn't preserve the subsecond portion of a time
274 * Updated translations for French, Galician, German, Japanese, Korean,
275 and Russian. New translations for Croatian, Danish, Hebrew, and
278 * Updated internationalization support to Gettext 0.11.5.
279 GNU make now uses Gettext's "external" feature, and does not include
280 any internationalization code itself. Configure will search your
281 system for an existing implementation of GNU Gettext (only GNU Gettext
282 is acceptable) and use it if it exists. If not, NLS will be disabled.
283 See ABOUT-NLS for more information.
285 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
287 A complete list of bugs fixed in this version is available here:
289 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
294 * .SECONDARY with no prerequisites now prevents any target from being
295 removed because make thinks it's an intermediate file, not just those
296 listed in the makefile.
298 * New configure option --disable-nsec-timestamps, but this was
299 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
303 * GNU make optionally supports internationalization and locales via the
304 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
305 file for more information on configuring GNU make for NLS.
307 * Previously, GNU make quoted variables such as MAKEFLAGS and
308 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
309 be used within make build scripts. However, using them there is not
310 proper behavior: they are meant to be passed to subshells via the
311 environment. Unfortunately the values were not quoted properly to be
312 passed through the environment. This meant that make didn't properly
313 pass some types of command line values to submakes.
315 With this version we change that behavior: now these variables are
316 quoted properly for passing through the environment, which is the
317 correct way to do it. If you previously used these variables
318 explicitly within a make rule you may need to re-examine your use for
319 correctness given this change.
321 * A new pseudo-target .NOTPARALLEL is available. If defined, the
322 current makefile is run serially regardless of the value of -j.
323 However, submakes are still eligible for parallel execution.
325 * The --debug option has changed: it now allows optional flags
326 controlling the amount and type of debugging output. By default only
327 a minimal amount information is generated, displaying the names of
328 "normal" targets (not makefiles) that were deemed out of date and in
329 need of being rebuilt.
331 Note that the -d option behaves as before: it takes no arguments and
332 all debugging information is generated.
334 * The `-p' (print database) output now includes filename and linenumber
335 information for variable definitions, to aid debugging.
337 * The wordlist function no longer reverses its arguments if the "start"
338 value is greater than the "end" value. If that's true, nothing is
341 * Hartmut Becker provided many updates for the VMS port of GNU make.
342 See the readme.vms file for more details.
346 * Two new functions, $(error ...) and $(warning ...) are available. The
347 former will cause make to fail and exit immediately upon expansion of
348 the function, with the text provided as the error message. The latter
349 causes the text provided to be printed as a warning message, but make
352 * A new function $(call ...) is available. This allows users to create
353 their own parameterized macros and invoke them later. Original
354 implementation of this function was provided by Han-Wen Nienhuys
357 * A new function $(if ...) is available. It provides if-then-else
358 capabilities in a builtin function. Original implementation of this
359 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
361 * Make defines a new variable, .LIBPATTERNS. This variable controls how
362 library dependency expansion (dependencies like ``-lfoo'') is performed.
364 * Make accepts CRLF sequences as well as traditional LF, for
365 compatibility with makefiles created on other operating systems.
367 * Make accepts a new option: -R, or --no-builtin-variables. This option
368 disables the definition of the rule-specific builtin variables (CC,
369 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
372 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
374 On systems that support POSIX pipe(2) semantics, GNU make can now pass
375 -jN options to submakes rather than forcing them all to use -j1. The
376 top make and all its sub-make processes use a pipe to communicate with
377 each other to ensure that no more than N jobs are started across all
378 makes. To get the old behavior of -j back, you can configure make
379 with the --disable-job-server option.
381 * The confusing term "dependency" has been replaced by the more accurate
382 and standard term "prerequisite", both in the manual and in all GNU make
385 * GNU make supports the "big archive" library format introduced in AIX 4.3.
387 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
388 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
389 support for Solaris and Linux was introduced in 3.77, but the
390 configuration had issues: these have also been resolved).
392 * The Windows 95/98/NT (W32) version of GNU make now has native support
393 for the Cygnus Cygwin release B20.1 shell (bash).
395 * The GNU make regression test suite, long available separately "under
396 the table", has been integrated into the release. You can invoke it
397 by running "make check" in the distribution. Note that it requires
398 Perl (either Perl 4 or Perl 5) to run.
402 * Implement BSD make's "?=" variable assignment operator. The variable
403 is assigned the specified value only if that variable is not already
406 * Make defines a new variable, "CURDIR", to contain the current working
407 directory (after the -C option, if any, has been processed).
408 Modifying this variable has no effect on the operation of make.
410 * Make defines a new default RCS rule, for new-style master file
411 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
413 Make defines new default rules for DOS-style C++ file naming
414 conventions, with ``.cpp'' suffixes. All the same rules as for
415 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
416 COMPILE.cpp macros (which default to the same value as LINK.cc and
417 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
418 use CXXFLAGS to change C++ compiler flags.
420 * A new feature, "target-specific variable values", has been added.
421 This is a large change so please see the appropriate sections of the
422 manual for full details. Briefly, syntax like this:
424 TARGET: VARIABLE = VALUE
426 defines VARIABLE as VALUE within the context of TARGET. This is
427 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
428 that the assignment may be of any type, not just recursive, and that
429 the override keyword is available.
431 COMPATIBILITY: This new syntax means that if you have any rules where
432 the first or second dependency has an equal sign (=) in its name,
433 you'll have to escape them with a backslash: "foo : bar\=baz".
434 Further, if you have any dependencies which already contain "\=",
435 you'll have to escape both of them: "foo : bar\\\=baz".
437 * A new appendix listing the most common error and warning messages
438 generated by GNU make, with some explanation, has been added to the
439 GNU make User's Manual.
441 * Updates to the GNU make Customs library support (see README.customs).
443 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
444 and to the DOS port from Eli Zaretski (see README.DOS).
448 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
452 * GNU make now uses automake to control Makefile.in generation. This
453 should make it more consistent with the GNU standards.
455 * VPATH functionality has been changed to incorporate the VPATH+ patch,
456 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
459 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
460 were specified on the command line, if any. Modifying this variable
461 has no effect on the operation of make.
463 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
464 list of words from number S to number E (inclusive) of TEXT.
466 * Instead of an error, detection of future modification times gives a
467 warning and continues. The warning is repeated just before GNU make
468 exits, so it is less likely to be lost.
470 * Fix the $(basename) and $(suffix) functions so they only operate on
471 the last filename, not the entire string:
473 Command Old Result New Result
474 ------- ---------- ----------
476 $(basename a.b/c) a a.b/c
478 $(suffix a.b/c) b/c <empty>
480 * The $(strip) function now removes newlines as well as TABs and spaces.
482 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
485 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
487 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
488 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
489 and utilities. See README.DOS for details, and direct all questions
490 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
491 Delorie <dj@delorie.com>.
493 * John W. Eaton has updated the VMS port to support libraries and VPATH.
497 * The directory messages printed by `-w' and implicitly in sub-makes,
498 are now omitted if Make runs no commands and has no other messages to print.
500 * Make now detects files that for whatever reason have modification times
501 in the future and gives an error. Files with such impossible timestamps
502 can result from unsynchronized clocks, or archived distributions
503 containing bogus timestamps; they confuse Make's dependency engine
506 * The new directive `sinclude' is now recognized as another name for
507 `-include', for compatibility with some other Makes.
509 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
510 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
512 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
513 See README.W32 for details, and direct all Windows-related questions to
514 <rob_tulloh@tivoli.com>.
518 * Converted to use Autoconf version 2, so `configure' has some new options.
519 See INSTALL for details.
521 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
522 output enabled by -d, at any time during the run.
526 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
527 He is maintaining the DOS port, not the GNU Make maintainer;
528 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
529 MS-DOS binaries are available for FTP from ftp.simtel.net in
530 /pub/simtelnet/gnu/djgpp/.
532 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
533 contain variable definitions itself; these are treated just like
534 command line variable definitions. Make will automatically insert any
535 variable definitions from the environment value of `MAKEFLAGS' or from
536 the command line, into the `MAKEFLAGS' value exported to children. The
537 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
538 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
539 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
540 in the environment when its size is limited.
542 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
543 a rule if it has changed when its recipe exits with a nonzero status,
544 just as when the recipe gets a signal.
546 * The automatic variable `$+' is new. It lists all the dependencies like
547 `$^', but preserves duplicates listed in the makefile. This is useful
548 for linking rules, where library files sometimes need to be listed twice
551 * You can now specify the `.IGNORE' and `.SILENT' special targets with
552 dependencies to limit their effects to those files. If a file appears as
553 a dependency of `.IGNORE', then errors will be ignored while running the
554 recipe to update that file. Likewise if a file appears as a dependency
555 of `.SILENT', then the recipe to update that file will not be printed
556 before it is run. (This change was made to conform to POSIX.2.)
560 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
561 `$(^D)' now omit the trailing slash from the directory name. (This change
562 was made to comply with POSIX.2.)
564 * The source distribution now includes the Info files for the Make manual.
565 There is no longer a separate distribution containing Info and DVI files.
567 * You can now set the variables `binprefix' and/or `manprefix' in
568 Makefile.in (or on the command line when installing) to install GNU make
569 under a name other than `make' (i.e., ``make binprefix=g install''
570 installs GNU make as `gmake').
572 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
573 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
576 * The exit status of Make when it runs into errors is now 2 instead of 1.
577 The exit status is 1 only when using -q and some target is not up to date.
578 (This change was made to comply with POSIX.2.)
582 * It is no longer a fatal error to have a NUL character in a makefile.
583 You should never put a NUL in a makefile because it can have strange
584 results, but otherwise empty lines full of NULs (such as produced by
585 the `xmkmf' program) will always work fine.
587 * The error messages for nonexistent included makefiles now refer to the
588 makefile name and line number where the `include' appeared, so Emacs's
589 C-x ` command takes you there (in case it's a typo you need to fix).
593 * Implicit rule search for archive member references is now done in the
594 opposite order from previous versions: the whole target name `LIB(MEM)'
595 first, and just the member name and parentheses `(MEM)' second.
597 * Make now gives an error for an unterminated variable or function reference.
598 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
600 * The new default variable `MAKE_VERSION' gives the version number of
601 Make, and a string describing the remote job support compiled in (if any).
602 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
604 * Commands in an invocation of the `shell' function are no longer run
605 with a modified environment like recipes are. As in versions before
606 3.68, they now run with the environment that `make' started with. We
607 have reversed the change made in version 3.68 because it turned out to
608 cause a paradoxical situation in cases like:
610 export variable = $(shell echo value)
612 When Make attempted to put this variable in the environment for a
613 recipe, it would try expand the value by running the shell command
614 `echo value'. In version 3.68, because it constructed an environment
615 for that shell command in the same way, Make would begin to go into an
616 infinite loop and then get a fatal error when it detected the loop.
618 * The recipe given for `.DEFAULT' is now used for phony targets with no
623 * You can list several archive member names inside parenthesis:
624 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
626 * You can use wildcards inside archive member references. For example,
627 `lib(*.o)' expands to all existing members of `lib' whose names end in
628 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
629 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
630 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
632 * A suffix rule `.X.a' now produces two pattern rules:
633 (%.o): %.X # Previous versions produced only this.
634 %.a: %.X # Now produces this as well, just like other suffixes.
636 * The new flag `--warn-undefined-variables' says to issue a warning message
637 whenever Make expands a reference to an undefined variable.
639 * The new `-include' directive is just like `include' except that there is
640 no error (not even a warning) for a nonexistent makefile.
642 * Commands in an invocation of the `shell' function are now run with a
643 modified environment like recipes are, so you can use `export' et al
644 to set up variables for them. They used to run with the environment
645 that `make' started with.
649 * `make --version' (or `make -v') now exits immediately after printing
654 * Make now supports long-named members in `ar' archive files.
658 * Make now supports the `+=' syntax for a variable definition which appends
659 to the variable's previous value. See the section `Appending More Text
660 to Variables' in the manual for full details.
662 * The new option `--no-print-directory' inhibits the `-w' or
663 `--print-directory' feature. Make turns on `--print-directory'
664 automatically if you use `-C' or `--directory', and in sub-makes; some
665 users have found this behavior undesirable.
667 * The built-in implicit rules now support the alternative extension
668 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
672 * Make now uses a standard GNU `configure' script. See the new file
673 INSTALL for the new (and much simpler) installation procedure.
675 * There is now a shell script to build Make the first time, if you have no
676 other `make' program. `build.sh' is created by `configure'; see README.
678 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
680 * Elements of the `$^' and `$?' automatic variables that are archive
681 member references now list only the member name, as in Unix and POSIX.2.
683 * You should no longer ever need to specify the `-w' switch, which prints
684 the current directory before and after Make runs. The `-C' switch to
685 change directory, and recursive use of Make, now set `-w' automatically.
687 * Multiple double-colon rules for the same target will no longer have their
688 recipes run simultaneously under -j, as this could result in the two
689 recipes trying to change the file at the same time and interfering with
692 * The `SHELL' variable is now never taken from the environment.
693 Each makefile that wants a shell other than the default (/bin/sh) must
694 set SHELL itself. SHELL is always exported to child processes.
695 This change was made for compatibility with POSIX.2.
697 * Make now accepts long options. There is now an informative usage message
698 that tells you what all the options are and what they do. Try `make --help'.
700 * There are two new directives: `export' and `unexport'. All variables are
701 no longer automatically put into the environments of the recipe lines that
702 Make runs. Instead, only variables specified on the command line or in
703 the environment are exported by default. To export others, use:
705 or you can define variables with:
706 export VARIABLE = VALUE
708 export VARIABLE := VALUE
712 .EXPORT_ALL_VARIABLES:
713 to get the old behavior. See the node `Variables/Recursion' in the manual
714 for a full description.
716 * The recipe from the `.DEFAULT' special target is only applied to
717 targets which have no rules at all, not all targets with no recipe.
718 This change was made for compatibility with Unix make.
720 * All fatal error messages now contain `***', so they are easy to find in
723 * Dependency file names like `-lNAME' are now replaced with the actual file
724 name found, as with files found by normal directory search (VPATH).
725 The library file `libNAME.a' may now be found in the current directory,
726 which is checked before VPATH; the standard set of directories (/lib,
727 /usr/lib, /usr/local/lib) is now checked last.
728 See the node `Libraries/Search' in the manual for full details.
730 * A single `include' directive can now specify more than one makefile to
733 You can also use shell file name patterns in an `include' directive:
736 * The default directories to search for included makefiles, and for
737 libraries specified with `-lNAME', are now set by configuration.
739 * You can now use blanks as well as colons to separate the directories in a
740 search path for the `vpath' directive or the `VPATH' variable.
742 * You can now use variables and functions in the left hand side of a
743 variable assignment, as in "$(foo)bar = value".
745 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
746 The `MAKE_COMMAND' variable is now defined to the name with which make
749 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
750 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
751 problems with shells that cannot have `+' in environment variable names.
753 * The value of a recursively expanded variable is now expanded when putting
754 it into the environment for child processes. This change was made for
755 compatibility with Unix make.
757 * A rule with no targets before the `:' is now accepted and ignored.
758 This change was made for compatibility with SunOS 4 make.
759 We do not recommend that you write your makefiles to take advantage of this.
761 * The `-I' switch can now be used in MAKEFLAGS, and are put there
762 automatically just like other switches.
766 * Built-in rules for C++ source files with the `.C' suffix.
767 We still recommend that you use `.cc' instead.
769 * If a recipe is given too many times for a single target, the last one
770 given is used, and a warning message is printed.
772 * Error messages about makefiles are in standard GNU error format,
773 so C-x ` in Emacs works on them.
775 * Dependencies of pattern rules which contain no % need not actually exist
776 if they can be created (just like dependencies which do have a %).
780 * A message is always printed when Make decides there is nothing to be done.
781 It used to be that no message was printed for top-level phony targets
782 (because "`phony' is up to date" isn't quite right). Now a different
783 message "Nothing to be done for `phony'" is printed in that case.
785 * Archives on AIX now supposedly work.
787 * When the recipes specified for .DEFAULT are used to update a target,
788 the $< automatic variable is given the same value as $@ for that target.
789 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
793 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
794 variables while remaking makefiles, so recursive makes done while remaking
795 makefiles will behave properly.
797 * If the special target `.NOEXPORT' is specified in a makefile,
798 only variables that came from the environment and variables
799 defined on the command line are exported.
803 * Suffix rules may have dependencies (which are ignored).
807 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
808 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
812 * There is now a Unix man page for GNU Make. It is certainly not a
813 replacement for the Texinfo manual, but it documents the basic
814 functionality and the switches. For full documentation, you should
815 still read the Texinfo manual. Thanks to Dennis Morse of Stanford
816 University for contributing the initial version of this.
818 * Variables which are defined by default (e.g., `CC') will no longer be
819 put into the environment for child processes. (If these variables are
820 reset by the environment, makefiles, or the command line, they will
821 still go into the environment.)
823 * Makefiles which have recipes but no dependencies (and thus are always
824 considered out of date and in need of remaking), will not be remade (if they
825 were being remade only because they were makefiles). This means that GNU
826 Make will no longer go into an infinite loop when fed the makefiles that
827 `imake' (necessary to build X Windows) produces.
829 * There is no longer a warning for using the `vpath' directive with an explicit
830 pathname (instead of a `%' pattern).
834 * When removing intermediate files, only one `rm' command line is printed,
835 listing all file names.
837 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
838 These are the directory-only and file-only versions of `$^' and `$?'.
840 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
841 directory if it exists.
843 * The automatic variable `$($/)' is no longer defined.
845 * Leading `+' characters on a recipe line make that line be executed even
846 under -n, -t, or -q (as if the line contained `$(MAKE)').
848 * For recipe lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
849 only those lines are executed, not the entire recipe.
850 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
854 * Filenames in rules will now have ~ and ~USER expanded.
856 * The `-p' output has been changed so it can be used as a makefile.
857 (All information that isn't specified by makefiles is prefaced with comment
862 * The % character can be quoted with backslash in implicit pattern rules,
863 static pattern rules, `vpath' directives, and `patsubst', `filter', and
864 `filter-out' functions. A warning is issued if a `vpath' directive's
865 pattern contains no %.
867 * The `wildcard' variable expansion function now expands ~ and ~USER.
869 * Messages indicating failed recipe lines now contain the target name:
870 make: *** [target] Error 1
872 * The `-p' output format has been changed somewhat to look more like
873 makefile rules and to give all information that Make has about files.
879 * The `-l' switch with no argument removes any previous load-average limit.
881 * When the `-w' switch is in effect, and Make has updated makefiles,
882 it will write a `Leaving directory' message before re-executing itself.
883 This makes the `directory change tracking' changes to Emacs's compilation
884 commands work properly.
888 * The automatic variable `$*' is now defined for explicit rules,
889 as it is in Unix make.
893 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
894 specified without an argument (indicating infinite jobs).
895 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
897 * Make no longer checks hashed directories after running recipes.
898 The behavior implemented in 3.41 caused too much slowdown.
902 * A dependency is NOT considered newer than its dependent if
903 they have the same modification time. The behavior implemented
904 in 3.43 conflicts with RCS.
908 * Dependency loops are no longer fatal errors.
910 * A dependency is considered newer than its dependent if
911 they have the same modification time.
915 * The variables F77 and F77FLAGS are now set by default to $(FC) and
916 $(FFLAGS). Makefiles designed for System V make may use these variables in
917 explicit rules and expect them to be set. Unfortunately, there is no way to
918 make setting these affect the Fortran implicit rules unless FC and FFLAGS
919 are not used (and these are used by BSD make).
923 * Make now checks to see if its hashed directories are changed by recipes.
924 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
928 * The `shell' function no longer captures standard error output.
932 * A file beginning with a dot can be the default target if it also contains
933 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
937 * Archive member names are truncated to 15 characters.
939 * Yet more USG stuff.
941 * Minimal support for Microport System V (a 16-bit machine and a
942 brain-damaged compiler). This has even lower priority than other USG
943 support, so if it gets beyond trivial, I will take it out completely.
945 * Revamped default implicit rules (not much visible change).
947 * The -d and -p options can come from the environment.
951 * Improved support for USG and HPUX (hopefully).
953 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
954 equivalent to `$(patsubst a,b,$(foo))'.
956 * Defining .DEFAULT with no deps or recipe clears its recipe.
958 * New default implicit rules for .S (cpp, then as), and .sh (copy and
959 make executable). All default implicit rules that use cpp (even
960 indirectly), use $(CPPFLAGS).
964 * Giving the -j option with no arguments gives you infinite jobs.
968 * New option: "-l LOAD" says not to start any new jobs while others are
969 running if the load average is not below LOAD (a floating-point number).
971 * There is support in place for implementations of remote command execution
972 in Make. See the file remote.c.
976 * No more than 10 directories will be kept open at once.
977 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
981 * Archive files will have their modification times recorded before doing
982 anything that might change their modification times by updating an archive
987 * The `MAKELEVEL' variable is defined for use by makefiles.
991 * The recursion level indications in error messages are much shorter than
992 they were in version 3.14.
996 * Leading spaces before directives are ignored (as documented).
998 * Included makefiles can determine the default goal target.
999 (System V Make does it this way, so we are being compatible).
1003 * Variables that are defaults built into Make will not be put in the
1004 environment for children. This just saves some environment space and,
1005 except under -e, will be transparent to sub-makes.
1007 * Error messages from sub-makes will indicate the level of recursion.
1009 * Hopefully some speed-up for large directories due to a change in the
1010 directory hashing scheme.
1012 * One child will always get a standard input that is usable.
1014 * Default makefiles that don't exist will be remade and read in.
1018 * Count parentheses inside expansion function calls so you can
1019 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
1023 * Several bug fixes, including USG and Sun386i support.
1025 * `shell' function to expand shell commands a la `
1027 * If the `-d' flag is given, version information will be printed.
1029 * The `-c' option has been renamed to `-C' for compatibility with tar.
1031 * The `-p' option no longer inhibits other normal operation.
1033 * Makefiles will be updated and re-read if necessary.
1035 * Can now run several recipes at once (parallelism), -j option.
1037 * Error messages will contain the level of Make recursion, if any.
1039 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
1042 * A double-colon rule with no dependencies will always have its recipe run.
1043 (This is how both the BSD and System V versions of Make do it.)
1047 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
1049 -------------------------------------------------------------------------------
1050 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1051 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free
1052 Software Foundation, Inc. This file is part of GNU Make.
1054 GNU Make is free software; you can redistribute it and/or modify it under the
1055 terms of the GNU General Public License as published by the Free Software
1056 Foundation; either version 3 of the License, or (at your option) any later
1059 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1060 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1061 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1063 You should have received a copy of the GNU General Public License along with
1064 this program. If not, see <http://www.gnu.org/licenses/>.