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 POSIX standard for make was changed in the 2008 version in a
19 fundamentally incompatible way: make is required to invoke the shell as if
20 the '-e' flag were provided. Because this would break many makefiles that
21 have been written to conform to the original text of the standard, the
22 default behavior of GNU make remains to invoke the shell with simply '-c'.
23 However, any makefile specifying the .POSIX special target will follow the
24 new POSIX standard and pass '-e' to the shell. See also .SHELLFLAGS below.
26 * WARNING: Backward-incompatibility!
27 The '$?' variable now contains all prerequisites that caused the target to
28 be considered out of date, even if they do not exist (previously only
29 existing targets were provided in $?).
31 * WARNING: Backward-incompatibility!
32 As a result of parser enhancements, three backward-compatibility issues
33 exist: first, a prerequisite containing an "=" cannot be escaped with a
34 backslash any longer. You must create a variable containing an "=" and use
35 that variable in the prerequisite. Second, variable names can no longer
36 contain whitespace, unless you put the whitespace in a variable and use the
37 variable. Third, in previous versions of make it was sometimes not flagged
38 as an error for explicit and pattern targets to appear in the same rule.
39 Now this is always reported as an error.
41 * WARNING: Backward-incompatibility!
42 The pattern-specific variables and pattern rules are now applied in the
43 shortest stem first order instead of the definition order (variables
44 and rules with the same stem length are still applied in the definition
45 order). This produces the usually-desired behavior where more specific
46 patterns are preferred. To detect this feature search for 'shortest-stem'
47 in the .FEATURES special variable.
49 * WARNING: Backward-incompatibility!
50 The library search behavior has changed to be compatible with the standard
51 linker behavior. Prior to this version for prerequisites specified using
52 the -lfoo syntax make fist searched for libfoo.so in the current directory,
53 vpath directories, and system directories. If that didn't yield a match,
54 make then searched for libfoo.a in these directories. Starting with this
55 version make searches first for libfoo.so and then for libfoo.a in each
56 of these directories in order.
58 * New command line option: --eval=STRING causes STRING to be evaluated as
59 makefile syntax (akin to using the $(eval ...) function). The evaluation is
60 performed after all default rules and variables are defined, but before any
63 * New special variable: .RECIPEPREFIX allows you to reset the recipe
64 introduction character from the default (TAB) to something else. The first
65 character of this variable value is the new recipe introduction character.
66 If the variable is set to the empty string, TAB is used again. It can be
67 set and reset at will; recipes will use the value active when they were
68 first parsed. To detect this feature check the value of $(.RECIPEPREFIX).
70 * New special variable: .SHELLFLAGS allows you to change the options passed to
71 the shell when it invokes recipes. By default the value will be "-c" (or
72 "-ec" if .POSIX is set).
74 * New special target: .ONESHELL instructs make to invoke a single instance of
75 the shell and provide it with the entire recipe, regardless of how many
76 lines it contains. As a special feature to allow more straightforward
77 conversion of makefiles to use .ONESHELL, any recipe line control characters
78 ('@', '+', or '-') will be removed from the second and subsequent recipe
79 lines. This happens _only_ if the SHELL value is deemed to be a standard
80 POSIX-style shell. If not, then no interior line control characters are
81 removed (as they may be part of the scripting language used with the
84 * New variable modifier 'private': prefixing a variable assignment with the
85 modifier 'private' suppresses inheritance of that variable by
86 prerequisites. This is most useful for target- and pattern-specific
89 * New make directive: 'undefine' allows you to undefine a variable so
90 that it appears as if it was never set. Both $(flavor) and $(origin)
91 functions will return 'undefined' for such a variable. To detect this
92 feature search for 'undefine' in the .FEATURES special variable.
94 * The parser for variable assignments has been enhanced to allow multiple
95 modifiers ('export', 'override', 'private') on the same line as variables,
96 including define/endef variables, and in any order. Also, it is possible
97 to create variables and targets named as these modifiers.
99 * The 'define' make directive now allows a variable assignment operator after
100 the variable name, to allow for simple, conditional, or appending multi-line
106 * GNU make is ported to OS/2.
108 * GNU make is ported to MinGW. The MinGW build is only supported by
109 the build_w32.bat batch file; see the file README.W32 for more
112 * WARNING: Future backward-incompatibility!
113 Up to and including this release, the '$?' variable does not contain
114 any prerequisite that does not exist, even though that prerequisite
115 might have caused the target to rebuild. Starting with the _next_
116 release of GNU make, '$?' will contain all prerequisites that caused
117 the target to be considered out of date. See this Savannah bug:
118 http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051
120 * WARNING: Backward-incompatibility!
121 GNU make now implements a generic "second expansion" feature on the
122 prerequisites of both explicit and implicit (pattern) rules. In order
123 to enable this feature, the special target '.SECONDEXPANSION' must be
124 defined before the first target which takes advantage of it. If this
125 feature is enabled then after all rules have been parsed the
126 prerequisites are expanded again, this time with all the automatic
127 variables in scope. This means that in addition to using standard
128 SysV $$@ in prerequisites lists, you can also use complex functions
129 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
130 as well, where the second expansion occurs when the rule is matched.
131 However, this means that when '.SECONDEXPANSION' is enabled you must
132 double-quote any "$" in your filenames; instead of "foo: boo$$bar" you
133 now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature,
134 which used to be available by default, is now ONLY available when the
135 .SECONDEXPANSION target is defined. If your makefiles take advantage
136 of this SysV feature you will need to update them.
138 * WARNING: Backward-incompatibility!
139 In order to comply with POSIX, the way in which GNU make processes
140 backslash-newline sequences in recipes has changed. If your makefiles
141 use backslash-newline sequences inside of single-quoted strings in
142 recipes you will be impacted by this change. See the GNU make manual
143 subsection "Splitting Recipe Lines" (node "Splitting Lines"), in
144 section "Recipe Syntax", chapter "Writing Recipe in Rules", for
147 * WARNING: Backward-incompatibility!
148 Some previous versions of GNU make had a bug where "#" in a function
149 invocation such as $(shell ...) was treated as a make comment. A
150 workaround was to escape these with backslashes. This bug has been
151 fixed: if your makefile uses "\#" in a function invocation the
152 backslash is now preserved, so you'll need to remove it.
154 * New command line option: -L (--check-symlink-times). On systems that
155 support symbolic links, if this option is given then GNU make will
156 use the most recent modification time of any symbolic links that are
157 used to resolve target files. The default behavior remains as it
158 always has: use the modification time of the actual target file only.
160 * The "else" conditional line can now be followed by any other valid
161 conditional on the same line: this does not increase the depth of the
162 conditional nesting, so only one "endif" is required to close the
165 * All pattern-specific variables that match a given target are now used
166 (previously only the first match was used).
168 * Target-specific variables can be marked as exportable using the
171 * In a recursive $(call ...) context, any extra arguments from the outer
172 call are now masked in the context of the inner call.
174 * Implemented a solution for the "thundering herd" problem with "-j -l".
175 This version of GNU make uses an algorithm suggested by Thomas Riedl
176 <thomas.riedl@siemens.com> to track the number of jobs started in the
177 last second and artificially adjust GNU make's view of the system's
178 load average accordingly.
180 * New special variables available in this release:
181 - .INCLUDE_DIRS: Expands to a list of directories that make searches
182 for included makefiles.
183 - .FEATURES: Contains a list of special features available in this
185 - .DEFAULT_GOAL: Set the name of the default goal make will
186 use if no goals are provided on the command line.
187 - MAKE_RESTARTS: If set, then this is the number of times this
188 instance of make has been restarted (see "How Makefiles Are Remade"
190 - New automatic variable: $| (added in 3.80, actually): contains all
191 the order-only prerequisites defined for the target.
193 * New functions available in this release:
194 - $(lastword ...) returns the last word in the list. This gives
195 identical results as $(word $(words ...) ...), but is much faster.
196 - $(abspath ...) returns the absolute path (all "." and ".."
197 directories resolved, and any duplicate "/" characters removed) for
199 - $(realpath ...) returns the canonical pathname for each path
200 provided. The canonical pathname is the absolute pathname, with
201 all symbolic links resolved as well.
202 - $(info ...) prints its arguments to stdout. No makefile name or
203 line number info, etc. is printed.
204 - $(flavor ...) returns the flavor of a variable.
205 - $(or ...) provides a short-circuiting OR conditional: each argument
206 is expanded. The first true (non-empty) argument is returned; no
207 further arguments are expanded. Expands to empty if there are no
209 - $(and ...) provides a short-circuiting AND conditional: each
210 argument is expanded. The first false (empty) argument is
211 returned; no further arguments are expanded. Expands to the last
212 argument if all arguments are true.
214 * Changes made for POSIX compatibility:
215 - Only touch targets (under -t) if they have a recipe.
216 - Setting the SHELL make variable does NOT change the value of the
217 SHELL environment variable given to programs invoked by make. As
218 an enhancement to POSIX, if you export the make variable SHELL then
219 it will be set in the environment, just as before.
221 * On MS Windows systems, explicitly setting SHELL to a pathname ending
222 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
223 the DOS command interpreter in batch mode even if a UNIX-like shell
224 could be found on the system.
226 * On VMS there is now support for case-sensitive filesystems such as ODS5.
227 See the readme.vms file for information.
229 * Parallel builds (-jN) no longer require a working Bourne shell on
230 Windows platforms. They work even with the stock Windows shells, such
231 as cmd.exe and command.com.
233 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
234 should not be impacted.
236 * New translations for Swedish, Chinese (simplified), Ukrainian,
237 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
240 A complete list of bugs fixed in this version is available here:
242 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103
247 * A new feature exists: order-only prerequisites. These prerequisites
248 affect the order in which targets are built, but they do not impact
249 the rebuild/no-rebuild decision of their dependents. That is to say,
250 they allow you to require target B be built before target A, without
251 requiring that target A will always be rebuilt if target B is updated.
252 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
254 * For compatibility with SysV make, GNU make now supports the peculiar
255 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
256 This syntax is only valid within explicit and static pattern rules: it
257 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
258 <egp@free.fr> provided a patch implementing this feature; however, I
259 decided to implement it in a different way.
261 * The argument to the "ifdef" conditional is now expanded before it's
262 tested, so it can be a constructed variable name.
264 Similarly, the arguments to "export" (when not used in a variable
265 definition context) and "unexport" are also now expanded.
267 * A new function is defined: $(value ...). The argument to this
268 function is the _name_ of a variable. The result of the function is
269 the value of the variable, without having been expanded.
271 * A new function is defined: $(eval ...). The arguments to this
272 function should expand to makefile commands, which will then be
273 evaluated as if they had appeared in the makefile. In combination
274 with define/endef multiline variable definitions this is an extremely
275 powerful capability. The $(value ...) function is also sometimes
278 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
279 list of each makefile GNU make has read, or started to read, in the
280 order in which they were encountered. So, the last filename in the
281 list when a makefile is just being read (before any includes) is the
282 name of the current makefile.
284 * A new built-in variable is defined: $(.VARIABLES). When it is
285 expanded it returns a complete list of variable names defined by all
286 makefiles at that moment.
288 * A new command line option is defined, -B or --always-make. If
289 specified GNU make will consider all targets out-of-date even if they
290 would otherwise not be.
292 * The arguments to $(call ...) functions were being stored in $1, $2,
293 etc. as recursive variables, even though they are fully expanded
294 before assignment. This means that escaped dollar signs ($$ etc.)
295 were not behaving properly. Now the arguments are stored as simple
296 variables. This may mean that if you added extra escaping to your
297 $(call ...) function arguments you will need to undo it now.
299 * The variable invoked by $(call ...) can now be recursive: unlike other
300 variables it can reference itself and this will not produce an error
301 when it is used as the first argument to $(call ...) (but only then).
303 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
304 option --disable-nsec-timestamps. You might need this if your build
305 process depends on tools like "cp -p" preserving time stamps, since
306 "cp -p" (right now) doesn't preserve the subsecond portion of a time
309 * Updated translations for French, Galician, German, Japanese, Korean,
310 and Russian. New translations for Croatian, Danish, Hebrew, and
313 * Updated internationalization support to Gettext 0.11.5.
314 GNU make now uses Gettext's "external" feature, and does not include
315 any internationalization code itself. Configure will search your
316 system for an existing implementation of GNU Gettext (only GNU Gettext
317 is acceptable) and use it if it exists. If not, NLS will be disabled.
318 See ABOUT-NLS for more information.
320 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
322 A complete list of bugs fixed in this version is available here:
324 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
329 * .SECONDARY with no prerequisites now prevents any target from being
330 removed because make thinks it's an intermediate file, not just those
331 listed in the makefile.
333 * New configure option --disable-nsec-timestamps, but this was
334 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
338 * GNU make optionally supports internationalization and locales via the
339 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
340 file for more information on configuring GNU make for NLS.
342 * Previously, GNU make quoted variables such as MAKEFLAGS and
343 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
344 be used within make build scripts. However, using them there is not
345 proper behavior: they are meant to be passed to subshells via the
346 environment. Unfortunately the values were not quoted properly to be
347 passed through the environment. This meant that make didn't properly
348 pass some types of command line values to submakes.
350 With this version we change that behavior: now these variables are
351 quoted properly for passing through the environment, which is the
352 correct way to do it. If you previously used these variables
353 explicitly within a make rule you may need to re-examine your use for
354 correctness given this change.
356 * A new pseudo-target .NOTPARALLEL is available. If defined, the
357 current makefile is run serially regardless of the value of -j.
358 However, submakes are still eligible for parallel execution.
360 * The --debug option has changed: it now allows optional flags
361 controlling the amount and type of debugging output. By default only
362 a minimal amount information is generated, displaying the names of
363 "normal" targets (not makefiles) that were deemed out of date and in
364 need of being rebuilt.
366 Note that the -d option behaves as before: it takes no arguments and
367 all debugging information is generated.
369 * The `-p' (print database) output now includes filename and linenumber
370 information for variable definitions, to aid debugging.
372 * The wordlist function no longer reverses its arguments if the "start"
373 value is greater than the "end" value. If that's true, nothing is
376 * Hartmut Becker provided many updates for the VMS port of GNU make.
377 See the readme.vms file for more details.
381 * Two new functions, $(error ...) and $(warning ...) are available. The
382 former will cause make to fail and exit immediately upon expansion of
383 the function, with the text provided as the error message. The latter
384 causes the text provided to be printed as a warning message, but make
387 * A new function $(call ...) is available. This allows users to create
388 their own parameterized macros and invoke them later. Original
389 implementation of this function was provided by Han-Wen Nienhuys
392 * A new function $(if ...) is available. It provides if-then-else
393 capabilities in a builtin function. Original implementation of this
394 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
396 * Make defines a new variable, .LIBPATTERNS. This variable controls how
397 library dependency expansion (dependencies like ``-lfoo'') is performed.
399 * Make accepts CRLF sequences as well as traditional LF, for
400 compatibility with makefiles created on other operating systems.
402 * Make accepts a new option: -R, or --no-builtin-variables. This option
403 disables the definition of the rule-specific builtin variables (CC,
404 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
407 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
409 On systems that support POSIX pipe(2) semantics, GNU make can now pass
410 -jN options to submakes rather than forcing them all to use -j1. The
411 top make and all its sub-make processes use a pipe to communicate with
412 each other to ensure that no more than N jobs are started across all
413 makes. To get the old behavior of -j back, you can configure make
414 with the --disable-job-server option.
416 * The confusing term "dependency" has been replaced by the more accurate
417 and standard term "prerequisite", both in the manual and in all GNU make
420 * GNU make supports the "big archive" library format introduced in AIX 4.3.
422 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
423 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
424 support for Solaris and Linux was introduced in 3.77, but the
425 configuration had issues: these have also been resolved).
427 * The Windows 95/98/NT (W32) version of GNU make now has native support
428 for the Cygnus Cygwin release B20.1 shell (bash).
430 * The GNU make regression test suite, long available separately "under
431 the table", has been integrated into the release. You can invoke it
432 by running "make check" in the distribution. Note that it requires
433 Perl (either Perl 4 or Perl 5) to run.
437 * Implement BSD make's "?=" variable assignment operator. The variable
438 is assigned the specified value only if that variable is not already
441 * Make defines a new variable, "CURDIR", to contain the current working
442 directory (after the -C option, if any, has been processed).
443 Modifying this variable has no effect on the operation of make.
445 * Make defines a new default RCS rule, for new-style master file
446 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
448 Make defines new default rules for DOS-style C++ file naming
449 conventions, with ``.cpp'' suffixes. All the same rules as for
450 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
451 COMPILE.cpp macros (which default to the same value as LINK.cc and
452 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
453 use CXXFLAGS to change C++ compiler flags.
455 * A new feature, "target-specific variable values", has been added.
456 This is a large change so please see the appropriate sections of the
457 manual for full details. Briefly, syntax like this:
459 TARGET: VARIABLE = VALUE
461 defines VARIABLE as VALUE within the context of TARGET. This is
462 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
463 that the assignment may be of any type, not just recursive, and that
464 the override keyword is available.
466 COMPATIBILITY: This new syntax means that if you have any rules where
467 the first or second dependency has an equal sign (=) in its name,
468 you'll have to escape them with a backslash: "foo : bar\=baz".
469 Further, if you have any dependencies which already contain "\=",
470 you'll have to escape both of them: "foo : bar\\\=baz".
472 * A new appendix listing the most common error and warning messages
473 generated by GNU make, with some explanation, has been added to the
474 GNU make User's Manual.
476 * Updates to the GNU make Customs library support (see README.customs).
478 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
479 and to the DOS port from Eli Zaretski (see README.DOS).
483 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
487 * GNU make now uses automake to control Makefile.in generation. This
488 should make it more consistent with the GNU standards.
490 * VPATH functionality has been changed to incorporate the VPATH+ patch,
491 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
494 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
495 were specified on the command line, if any. Modifying this variable
496 has no effect on the operation of make.
498 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
499 list of words from number S to number E (inclusive) of TEXT.
501 * Instead of an error, detection of future modification times gives a
502 warning and continues. The warning is repeated just before GNU make
503 exits, so it is less likely to be lost.
505 * Fix the $(basename) and $(suffix) functions so they only operate on
506 the last filename, not the entire string:
508 Command Old Result New Result
509 ------- ---------- ----------
511 $(basename a.b/c) a a.b/c
513 $(suffix a.b/c) b/c <empty>
515 * The $(strip) function now removes newlines as well as TABs and spaces.
517 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
520 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
522 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
523 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
524 and utilities. See README.DOS for details, and direct all questions
525 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
526 Delorie <dj@delorie.com>.
528 * John W. Eaton has updated the VMS port to support libraries and VPATH.
532 * The directory messages printed by `-w' and implicitly in sub-makes,
533 are now omitted if Make runs no commands and has no other messages to print.
535 * Make now detects files that for whatever reason have modification times
536 in the future and gives an error. Files with such impossible timestamps
537 can result from unsynchronized clocks, or archived distributions
538 containing bogus timestamps; they confuse Make's dependency engine
541 * The new directive `sinclude' is now recognized as another name for
542 `-include', for compatibility with some other Makes.
544 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
545 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
547 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
548 See README.W32 for details, and direct all Windows-related questions to
549 <rob_tulloh@tivoli.com>.
553 * Converted to use Autoconf version 2, so `configure' has some new options.
554 See INSTALL for details.
556 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
557 output enabled by -d, at any time during the run.
561 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
562 He is maintaining the DOS port, not the GNU Make maintainer;
563 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
564 MS-DOS binaries are available for FTP from ftp.simtel.net in
565 /pub/simtelnet/gnu/djgpp/.
567 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
568 contain variable definitions itself; these are treated just like
569 command line variable definitions. Make will automatically insert any
570 variable definitions from the environment value of `MAKEFLAGS' or from
571 the command line, into the `MAKEFLAGS' value exported to children. The
572 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
573 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
574 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
575 in the environment when its size is limited.
577 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
578 a rule if it has changed when its recipe exits with a nonzero status,
579 just as when the recipe gets a signal.
581 * The automatic variable `$+' is new. It lists all the dependencies like
582 `$^', but preserves duplicates listed in the makefile. This is useful
583 for linking rules, where library files sometimes need to be listed twice
586 * You can now specify the `.IGNORE' and `.SILENT' special targets with
587 dependencies to limit their effects to those files. If a file appears as
588 a dependency of `.IGNORE', then errors will be ignored while running the
589 recipe to update that file. Likewise if a file appears as a dependency
590 of `.SILENT', then the recipe to update that file will not be printed
591 before it is run. (This change was made to conform to POSIX.2.)
595 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
596 `$(^D)' now omit the trailing slash from the directory name. (This change
597 was made to comply with POSIX.2.)
599 * The source distribution now includes the Info files for the Make manual.
600 There is no longer a separate distribution containing Info and DVI files.
602 * You can now set the variables `binprefix' and/or `manprefix' in
603 Makefile.in (or on the command line when installing) to install GNU make
604 under a name other than `make' (i.e., ``make binprefix=g install''
605 installs GNU make as `gmake').
607 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
608 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
611 * The exit status of Make when it runs into errors is now 2 instead of 1.
612 The exit status is 1 only when using -q and some target is not up to date.
613 (This change was made to comply with POSIX.2.)
617 * It is no longer a fatal error to have a NUL character in a makefile.
618 You should never put a NUL in a makefile because it can have strange
619 results, but otherwise empty lines full of NULs (such as produced by
620 the `xmkmf' program) will always work fine.
622 * The error messages for nonexistent included makefiles now refer to the
623 makefile name and line number where the `include' appeared, so Emacs's
624 C-x ` command takes you there (in case it's a typo you need to fix).
628 * Implicit rule search for archive member references is now done in the
629 opposite order from previous versions: the whole target name `LIB(MEM)'
630 first, and just the member name and parentheses `(MEM)' second.
632 * Make now gives an error for an unterminated variable or function reference.
633 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
635 * The new default variable `MAKE_VERSION' gives the version number of
636 Make, and a string describing the remote job support compiled in (if any).
637 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
639 * Commands in an invocation of the `shell' function are no longer run
640 with a modified environment like recipes are. As in versions before
641 3.68, they now run with the environment that `make' started with. We
642 have reversed the change made in version 3.68 because it turned out to
643 cause a paradoxical situation in cases like:
645 export variable = $(shell echo value)
647 When Make attempted to put this variable in the environment for a
648 recipe, it would try expand the value by running the shell command
649 `echo value'. In version 3.68, because it constructed an environment
650 for that shell command in the same way, Make would begin to go into an
651 infinite loop and then get a fatal error when it detected the loop.
653 * The recipe given for `.DEFAULT' is now used for phony targets with no
658 * You can list several archive member names inside parenthesis:
659 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
661 * You can use wildcards inside archive member references. For example,
662 `lib(*.o)' expands to all existing members of `lib' whose names end in
663 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
664 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
665 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
667 * A suffix rule `.X.a' now produces two pattern rules:
668 (%.o): %.X # Previous versions produced only this.
669 %.a: %.X # Now produces this as well, just like other suffixes.
671 * The new flag `--warn-undefined-variables' says to issue a warning message
672 whenever Make expands a reference to an undefined variable.
674 * The new `-include' directive is just like `include' except that there is
675 no error (not even a warning) for a nonexistent makefile.
677 * Commands in an invocation of the `shell' function are now run with a
678 modified environment like recipes are, so you can use `export' et al
679 to set up variables for them. They used to run with the environment
680 that `make' started with.
684 * `make --version' (or `make -v') now exits immediately after printing
689 * Make now supports long-named members in `ar' archive files.
693 * Make now supports the `+=' syntax for a variable definition which appends
694 to the variable's previous value. See the section `Appending More Text
695 to Variables' in the manual for full details.
697 * The new option `--no-print-directory' inhibits the `-w' or
698 `--print-directory' feature. Make turns on `--print-directory'
699 automatically if you use `-C' or `--directory', and in sub-makes; some
700 users have found this behavior undesirable.
702 * The built-in implicit rules now support the alternative extension
703 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
707 * Make now uses a standard GNU `configure' script. See the new file
708 INSTALL for the new (and much simpler) installation procedure.
710 * There is now a shell script to build Make the first time, if you have no
711 other `make' program. `build.sh' is created by `configure'; see README.
713 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
715 * Elements of the `$^' and `$?' automatic variables that are archive
716 member references now list only the member name, as in Unix and POSIX.2.
718 * You should no longer ever need to specify the `-w' switch, which prints
719 the current directory before and after Make runs. The `-C' switch to
720 change directory, and recursive use of Make, now set `-w' automatically.
722 * Multiple double-colon rules for the same target will no longer have their
723 recipes run simultaneously under -j, as this could result in the two
724 recipes trying to change the file at the same time and interfering with
727 * The `SHELL' variable is now never taken from the environment.
728 Each makefile that wants a shell other than the default (/bin/sh) must
729 set SHELL itself. SHELL is always exported to child processes.
730 This change was made for compatibility with POSIX.2.
732 * Make now accepts long options. There is now an informative usage message
733 that tells you what all the options are and what they do. Try `make --help'.
735 * There are two new directives: `export' and `unexport'. All variables are
736 no longer automatically put into the environments of the recipe lines that
737 Make runs. Instead, only variables specified on the command line or in
738 the environment are exported by default. To export others, use:
740 or you can define variables with:
741 export VARIABLE = VALUE
743 export VARIABLE := VALUE
747 .EXPORT_ALL_VARIABLES:
748 to get the old behavior. See the node `Variables/Recursion' in the manual
749 for a full description.
751 * The recipe from the `.DEFAULT' special target is only applied to
752 targets which have no rules at all, not all targets with no recipe.
753 This change was made for compatibility with Unix make.
755 * All fatal error messages now contain `***', so they are easy to find in
758 * Dependency file names like `-lNAME' are now replaced with the actual file
759 name found, as with files found by normal directory search (VPATH).
760 The library file `libNAME.a' may now be found in the current directory,
761 which is checked before VPATH; the standard set of directories (/lib,
762 /usr/lib, /usr/local/lib) is now checked last.
763 See the node `Libraries/Search' in the manual for full details.
765 * A single `include' directive can now specify more than one makefile to
768 You can also use shell file name patterns in an `include' directive:
771 * The default directories to search for included makefiles, and for
772 libraries specified with `-lNAME', are now set by configuration.
774 * You can now use blanks as well as colons to separate the directories in a
775 search path for the `vpath' directive or the `VPATH' variable.
777 * You can now use variables and functions in the left hand side of a
778 variable assignment, as in "$(foo)bar = value".
780 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
781 The `MAKE_COMMAND' variable is now defined to the name with which make
784 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
785 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
786 problems with shells that cannot have `+' in environment variable names.
788 * The value of a recursively expanded variable is now expanded when putting
789 it into the environment for child processes. This change was made for
790 compatibility with Unix make.
792 * A rule with no targets before the `:' is now accepted and ignored.
793 This change was made for compatibility with SunOS 4 make.
794 We do not recommend that you write your makefiles to take advantage of this.
796 * The `-I' switch can now be used in MAKEFLAGS, and are put there
797 automatically just like other switches.
801 * Built-in rules for C++ source files with the `.C' suffix.
802 We still recommend that you use `.cc' instead.
804 * If a recipe is given too many times for a single target, the last one
805 given is used, and a warning message is printed.
807 * Error messages about makefiles are in standard GNU error format,
808 so C-x ` in Emacs works on them.
810 * Dependencies of pattern rules which contain no % need not actually exist
811 if they can be created (just like dependencies which do have a %).
815 * A message is always printed when Make decides there is nothing to be done.
816 It used to be that no message was printed for top-level phony targets
817 (because "`phony' is up to date" isn't quite right). Now a different
818 message "Nothing to be done for `phony'" is printed in that case.
820 * Archives on AIX now supposedly work.
822 * When the recipes specified for .DEFAULT are used to update a target,
823 the $< automatic variable is given the same value as $@ for that target.
824 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
828 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
829 variables while remaking makefiles, so recursive makes done while remaking
830 makefiles will behave properly.
832 * If the special target `.NOEXPORT' is specified in a makefile,
833 only variables that came from the environment and variables
834 defined on the command line are exported.
838 * Suffix rules may have dependencies (which are ignored).
842 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
843 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
847 * There is now a Unix man page for GNU Make. It is certainly not a
848 replacement for the Texinfo manual, but it documents the basic
849 functionality and the switches. For full documentation, you should
850 still read the Texinfo manual. Thanks to Dennis Morse of Stanford
851 University for contributing the initial version of this.
853 * Variables which are defined by default (e.g., `CC') will no longer be
854 put into the environment for child processes. (If these variables are
855 reset by the environment, makefiles, or the command line, they will
856 still go into the environment.)
858 * Makefiles which have recipes but no dependencies (and thus are always
859 considered out of date and in need of remaking), will not be remade (if they
860 were being remade only because they were makefiles). This means that GNU
861 Make will no longer go into an infinite loop when fed the makefiles that
862 `imake' (necessary to build X Windows) produces.
864 * There is no longer a warning for using the `vpath' directive with an explicit
865 pathname (instead of a `%' pattern).
869 * When removing intermediate files, only one `rm' command line is printed,
870 listing all file names.
872 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
873 These are the directory-only and file-only versions of `$^' and `$?'.
875 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
876 directory if it exists.
878 * The automatic variable `$($/)' is no longer defined.
880 * Leading `+' characters on a recipe line make that line be executed even
881 under -n, -t, or -q (as if the line contained `$(MAKE)').
883 * For recipe lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
884 only those lines are executed, not the entire recipe.
885 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
889 * Filenames in rules will now have ~ and ~USER expanded.
891 * The `-p' output has been changed so it can be used as a makefile.
892 (All information that isn't specified by makefiles is prefaced with comment
897 * The % character can be quoted with backslash in implicit pattern rules,
898 static pattern rules, `vpath' directives, and `patsubst', `filter', and
899 `filter-out' functions. A warning is issued if a `vpath' directive's
900 pattern contains no %.
902 * The `wildcard' variable expansion function now expands ~ and ~USER.
904 * Messages indicating failed recipe lines now contain the target name:
905 make: *** [target] Error 1
907 * The `-p' output format has been changed somewhat to look more like
908 makefile rules and to give all information that Make has about files.
914 * The `-l' switch with no argument removes any previous load-average limit.
916 * When the `-w' switch is in effect, and Make has updated makefiles,
917 it will write a `Leaving directory' message before re-executing itself.
918 This makes the `directory change tracking' changes to Emacs's compilation
919 commands work properly.
923 * The automatic variable `$*' is now defined for explicit rules,
924 as it is in Unix make.
928 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
929 specified without an argument (indicating infinite jobs).
930 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
932 * Make no longer checks hashed directories after running recipes.
933 The behavior implemented in 3.41 caused too much slowdown.
937 * A dependency is NOT considered newer than its dependent if
938 they have the same modification time. The behavior implemented
939 in 3.43 conflicts with RCS.
943 * Dependency loops are no longer fatal errors.
945 * A dependency is considered newer than its dependent if
946 they have the same modification time.
950 * The variables F77 and F77FLAGS are now set by default to $(FC) and
951 $(FFLAGS). Makefiles designed for System V make may use these variables in
952 explicit rules and expect them to be set. Unfortunately, there is no way to
953 make setting these affect the Fortran implicit rules unless FC and FFLAGS
954 are not used (and these are used by BSD make).
958 * Make now checks to see if its hashed directories are changed by recipes.
959 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
963 * The `shell' function no longer captures standard error output.
967 * A file beginning with a dot can be the default target if it also contains
968 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
972 * Archive member names are truncated to 15 characters.
974 * Yet more USG stuff.
976 * Minimal support for Microport System V (a 16-bit machine and a
977 brain-damaged compiler). This has even lower priority than other USG
978 support, so if it gets beyond trivial, I will take it out completely.
980 * Revamped default implicit rules (not much visible change).
982 * The -d and -p options can come from the environment.
986 * Improved support for USG and HPUX (hopefully).
988 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
989 equivalent to `$(patsubst a,b,$(foo))'.
991 * Defining .DEFAULT with no deps or recipe clears its recipe.
993 * New default implicit rules for .S (cpp, then as), and .sh (copy and
994 make executable). All default implicit rules that use cpp (even
995 indirectly), use $(CPPFLAGS).
999 * Giving the -j option with no arguments gives you infinite jobs.
1003 * New option: "-l LOAD" says not to start any new jobs while others are
1004 running if the load average is not below LOAD (a floating-point number).
1006 * There is support in place for implementations of remote command execution
1007 in Make. See the file remote.c.
1011 * No more than 10 directories will be kept open at once.
1012 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
1016 * Archive files will have their modification times recorded before doing
1017 anything that might change their modification times by updating an archive
1022 * The `MAKELEVEL' variable is defined for use by makefiles.
1026 * The recursion level indications in error messages are much shorter than
1027 they were in version 3.14.
1031 * Leading spaces before directives are ignored (as documented).
1033 * Included makefiles can determine the default goal target.
1034 (System V Make does it this way, so we are being compatible).
1038 * Variables that are defaults built into Make will not be put in the
1039 environment for children. This just saves some environment space and,
1040 except under -e, will be transparent to sub-makes.
1042 * Error messages from sub-makes will indicate the level of recursion.
1044 * Hopefully some speed-up for large directories due to a change in the
1045 directory hashing scheme.
1047 * One child will always get a standard input that is usable.
1049 * Default makefiles that don't exist will be remade and read in.
1053 * Count parentheses inside expansion function calls so you can
1054 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
1058 * Several bug fixes, including USG and Sun386i support.
1060 * `shell' function to expand shell commands a la `
1062 * If the `-d' flag is given, version information will be printed.
1064 * The `-c' option has been renamed to `-C' for compatibility with tar.
1066 * The `-p' option no longer inhibits other normal operation.
1068 * Makefiles will be updated and re-read if necessary.
1070 * Can now run several recipes at once (parallelism), -j option.
1072 * Error messages will contain the level of Make recursion, if any.
1074 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
1077 * A double-colon rule with no dependencies will always have its recipe run.
1078 (This is how both the BSD and System V versions of Make do it.)
1082 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
1084 -------------------------------------------------------------------------------
1085 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1086 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free
1087 Software Foundation, Inc. This file is part of GNU Make.
1089 GNU Make is free software; you can redistribute it and/or modify it under the
1090 terms of the GNU General Public License as published by the Free Software
1091 Foundation; either version 3 of the License, or (at your option) any later
1094 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
1095 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
1096 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
1098 You should have received a copy of the GNU General Public License along with
1099 this program. If not, see <http://www.gnu.org/licenses/>.