1 GNU make NEWS -*-indented-text-*-
2 History of user-visible changes.
5 Copyright (C) 2002,2003,2004,2005 Free Software Foundation, Inc.
6 See the end for copying conditions.
8 All changes mentioned here are more fully described in the GNU make
9 manual, which is contained in this distribution as the file doc/make.texi.
10 See the README file and the GNU make manual for instructions for
15 * GNU make is ported to OS/2.
17 * GNU make is ported to MinGW. The MinGW build is only supported by
18 the build_w32.bat batch file; see the file README.W32 for more
21 * WARNING: Backward-incompatibility!
22 GNU make now implements a generic "second expansion" feature on the
23 prerequisites of both explicit and implicit (pattern) rules. In order
24 to enable this feature, the special target '.SECONDEXPANSION' must be
25 defined before the first target which takes advantage of it. If this
26 feature is enabled then after all rules have been parsed the
27 prerequisites are expanded again, this time with all the automatic
28 variables in scope. This means that in addition to using standard
29 SysV $$@ in prerequisites lists, you can also use complex functions
30 such as $$(notdir $$@) etc. This behavior applies to implicit rules,
31 as well, where the second expansion occurs when the rule is matched.
32 However, this means that you need to double-quote any "$" in your
33 filenames; instead of "foo: boo$$bar" you now must write "foo:
34 foo$$$$bar". Note that the SysV $$@ etc. feature, which used to be
35 available by default, is now ONLY available when the .SECONDEXPANSION
36 target is defined. If your makefiles take advantage of this SysV
37 feature you will need to update them.
39 * WARNING: Backward-incompatibility!
40 In order to comply with POSIX, the way in which GNU make processes
41 backslash-newline sequences in command strings has changed. If your
42 makefiles use backslash-newline sequences inside of single-quoted
43 strings in command scripts you will be impacted by this change. See
44 the GNU make manual section "Command Execution" (node "Execution") for
47 * New command-line option: -L (--check-symlink-times). On systems that
48 support symbolic links, if this option is given then GNU make will
49 use the most recent modification time of any symbolic links that are
50 used to resolve target files. The default behavior remains as it
51 always has: use the modification time of the actual target file only.
53 * The "else" conditional line can now be followed by any other valid
54 conditional on the same line: this does not increase the depth of the
55 conditional nesting, so only one "endif" is required to close the
58 * All pattern-specific variables that match a given target are now used
59 (previously only the first match was used).
61 * Target-specific variables can be marked as exportable using the
64 * In a recursive $(call ...) context, any extra arguments from the outer
65 call are now masked in the context of the inner call.
67 * Implemented a solution for the "thundering herd" problem with "-j -l".
68 This version of GNU make uses an algorithm suggested by Thomas Riedl
69 <thomas.riedl@siemens.com> to track the number of jobs started in the
70 last second and artificially adjust GNU make's view of the system's
71 load average accordingly.
73 * New special variables available in this release:
74 - .INCLUDE_DIRS: Expands to a list of directories that make searches
75 for included makefiles.
76 - .FEATURES: Contains a list of special features available in this
78 - .DEFAULT_GOAL: Set the name of the default goal make will
79 use if no goals are provided on the command line.
80 - MAKE_RESTARTS: If set, then this is the number of times this
81 instance of make has been restarted (see "How Makefiles Are Remade"
83 - New automatic variable: $| (added in 3.80, actually): contains all
84 the order-only prerequisites defined for the target.
86 * New functions available in this release:
87 - $(lastword ...) returns the last word in the list. This gives
88 identical results as $(word $(words ...) ...), but is much faster.
89 - $(abspath ...) returns the absolute path (all "." and ".."
90 directories resolved, and any duplicate "/" characters removed) for
92 - $(realpath ...) returns the canonical pathname for each path
93 provided. The canonical pathname is the absolute pathname, with
94 all symbolic links resolved as well.
95 - $(info ...) prints its arguments to stdout. No makefile name or
96 line number info, etc. is printed.
97 - $(flavor ...) returns the flavor of a variable.
99 * Changes made for POSIX compatibility:
100 - Only touch targets (under -t) if they have at least one command.
101 - Setting the SHELL make variable does NOT change the value of the
102 SHELL environment variable given to programs invoked by make. As
103 an enhancement to POSIX, if you export the make variable SHELL then
104 it will be set in the environment, just as before.
106 * On MS Windows systems, explicitly setting SHELL to a pathname ending
107 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
108 the DOS command interpreter in batch mode even if a UNIX-like shell
109 could be found on the system.
111 * On VMS there is now support for case-sensitive filesystems such as ODS5.
112 See the readme.vms file for information.
114 * Parallel builds (-jN) no longer require a working Bourne shell on
115 Windows platforms. They work even with the stock Windows shells, such
116 as cmd.exe and command.com.
118 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
119 should not be impacted.
121 * New translations for Swedish, Chinese (simplified), Ukrainian,
122 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
125 A complete list of bugs fixed in this version is available here:
127 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=101
132 * A new feature exists: order-only prerequisites. These prerequisites
133 affect the order in which targets are built, but they do not impact
134 the rebuild/no-rebuild decision of their dependents. That is to say,
135 they allow you to require target B be built before target A, without
136 requiring that target A will always be rebuilt if target B is updated.
137 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
139 * For compatibility with SysV make, GNU make now supports the peculiar
140 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
141 This syntax is only valid within explicit and static pattern rules: it
142 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
143 <egp@free.fr> provided a patch implementing this feature; however, I
144 decided to implement it in a different way.
146 * The argument to the "ifdef" conditional is now expanded before it's
147 tested, so it can be a constructed variable name.
149 Similarly, the arguments to "export" (when not used in a variable
150 definition context) and "unexport" are also now expanded.
152 * A new function is defined: $(value ...). The argument to this
153 function is the _name_ of a variable. The result of the function is
154 the value of the variable, without having been expanded.
156 * A new function is defined: $(eval ...). The arguments to this
157 function should expand to makefile commands, which will then be
158 evaluated as if they had appeared in the makefile. In combination
159 with define/endef multiline variable definitions this is an extremely
160 powerful capability. The $(value ...) function is also sometimes
163 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
164 list of each makefile GNU make has read, or started to read, in the
165 order in which they were encountered. So, the last filename in the
166 list when a makefile is just being read (before any includes) is the
167 name of the current makefile.
169 * A new built-in variable is defined: $(.VARIABLES). When it is
170 expanded it returns a complete list of variable names defined by all
171 makefiles at that moment.
173 * A new command-line option is defined, -B or --always-make. If
174 specified GNU make will consider all targets out-of-date even if they
175 would otherwise not be.
177 * The arguments to $(call ...) functions were being stored in $1, $2,
178 etc. as recursive variables, even though they are fully expanded
179 before assignment. This means that escaped dollar signs ($$ etc.)
180 were not behaving properly. Now the arguments are stored as simple
181 variables. This may mean that if you added extra escaping to your
182 $(call ...) function arguments you will need to undo it now.
184 * The variable invoked by $(call ...) can now be recursive: unlike other
185 variables it can reference itself and this will not produce an error
186 when it is used as the first argument to $(call ...) (but only then).
188 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
189 option --disable-nsec-timestamps. You might need this if your build
190 process depends on tools like "cp -p" preserving time stamps, since
191 "cp -p" (right now) doesn't preserve the subsecond portion of a time
194 * Updated translations for French, Galician, German, Japanese, Korean,
195 and Russian. New translations for Croatian, Danish, Hebrew, and
198 * Updated internationalization support to Gettext 0.11.5.
199 GNU make now uses Gettext's "external" feature, and does not include
200 any internationalization code itself. Configure will search your
201 system for an existing implementation of GNU Gettext (only GNU Gettext
202 is acceptable) and use it if it exists. If not, NLS will be disabled.
203 See ABOUT-NLS for more information.
205 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
207 A complete list of bugs fixed in this version is available here:
209 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
214 * .SECONDARY with no prerequisites now prevents any target from being
215 removed because make thinks it's an intermediate file, not just those
216 listed in the makefile.
218 * New configure option --disable-nsec-timestamps, but this was
219 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
223 * GNU make optionally supports internationalization and locales via the
224 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
225 file for more information on configuring GNU make for NLS.
227 * Previously, GNU make quoted variables such as MAKEFLAGS and
228 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
229 be used within make build scripts. However, using them there is not
230 proper behavior: they are meant to be passed to subshells via the
231 environment. Unfortunately the values were not quoted properly to be
232 passed through the environment. This meant that make didn't properly
233 pass some types of command line values to submakes.
235 With this version we change that behavior: now these variables are
236 quoted properly for passing through the environment, which is the
237 correct way to do it. If you previously used these variables
238 explicitly within a make rule you may need to re-examine your use for
239 correctness given this change.
241 * A new pseudo-target .NOTPARALLEL is available. If defined, the
242 current makefile is run serially regardless of the value of -j.
243 However, submakes are still eligible for parallel execution.
245 * The --debug option has changed: it now allows optional flags
246 controlling the amount and type of debugging output. By default only
247 a minimal amount information is generated, displaying the names of
248 "normal" targets (not makefiles) that were deemed out of date and in
249 need of being rebuilt.
251 Note that the -d option behaves as before: it takes no arguments and
252 all debugging information is generated.
254 * The `-p' (print database) output now includes filename and linenumber
255 information for variable definitions, to aid debugging.
257 * The wordlist function no longer reverses its arguments if the "start"
258 value is greater than the "end" value. If that's true, nothing is
261 * Hartmut Becker provided many updates for the VMS port of GNU make.
262 See the readme.vms file for more details.
266 * Two new functions, $(error ...) and $(warning ...) are available. The
267 former will cause make to fail and exit immediately upon expansion of
268 the function, with the text provided as the error message. The latter
269 causes the text provided to be printed as a warning message, but make
272 * A new function $(call ...) is available. This allows users to create
273 their own parameterized macros and invoke them later. Original
274 implementation of this function was provided by Han-Wen Nienhuys
277 * A new function $(if ...) is available. It provides if-then-else
278 capabilities in a builtin function. Original implementation of this
279 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
281 * Make defines a new variable, .LIBPATTERNS. This variable controls how
282 library dependency expansion (dependencies like ``-lfoo'') is performed.
284 * Make accepts CRLF sequences as well as traditional LF, for
285 compatibility with makefiles created on other operating systems.
287 * Make accepts a new option: -R, or --no-builtin-variables. This option
288 disables the definition of the rule-specific builtin variables (CC,
289 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
292 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
294 On systems that support POSIX pipe(2) semantics, GNU make can now pass
295 -jN options to submakes rather than forcing them all to use -j1. The
296 top make and all its sub-make processes use a pipe to communicate with
297 each other to ensure that no more than N jobs are started across all
298 makes. To get the old behavior of -j back, you can configure make
299 with the --disable-job-server option.
301 * The confusing term "dependency" has been replaced by the more accurate
302 and standard term "prerequisite", both in the manual and in all GNU make
305 * GNU make supports the "big archive" library format introduced in AIX 4.3.
307 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
308 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
309 support for Solaris and Linux was introduced in 3.77, but the
310 configuration had issues: these have also been resolved).
312 * The Windows 95/98/NT (W32) version of GNU make now has native support
313 for the Cygnus Cygwin release B20.1 shell (bash).
315 * The GNU make regression test suite, long available separately "under
316 the table", has been integrated into the release. You can invoke it
317 by running "make check" in the distribution. Note that it requires
318 Perl (either Perl 4 or Perl 5) to run.
322 * Implement BSD make's "?=" variable assignment operator. The variable
323 is assigned the specified value only if that variable is not already
326 * Make defines a new variable, "CURDIR", to contain the current working
327 directory (after the -C option, if any, has been processed).
328 Modifying this variable has no effect on the operation of make.
330 * Make defines a new default RCS rule, for new-style master file
331 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
333 Make defines new default rules for DOS-style C++ file naming
334 conventions, with ``.cpp'' suffixes. All the same rules as for
335 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
336 COMPILE.cpp macros (which default to the same value as LINK.cc and
337 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
338 use CXXFLAGS to change C++ compiler flags.
340 * A new feature, "target-specific variable values", has been added.
341 This is a large change so please see the appropriate sections of the
342 manual for full details. Briefly, syntax like this:
344 TARGET: VARIABLE = VALUE
346 defines VARIABLE as VALUE within the context of TARGET. This is
347 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
348 that the assignment may be of any type, not just recursive, and that
349 the override keyword is available.
351 COMPATIBILITY: This new syntax means that if you have any rules where
352 the first or second dependency has an equal sign (=) in its name,
353 you'll have to escape them with a backslash: "foo : bar\=baz".
354 Further, if you have any dependencies which already contain "\=",
355 you'll have to escape both of them: "foo : bar\\\=baz".
357 * A new appendix listing the most common error and warning messages
358 generated by GNU make, with some explanation, has been added to the
359 GNU make User's Manual.
361 * Updates to the GNU make Customs library support (see README.customs).
363 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
364 and to the DOS port from Eli Zaretski (see README.DOS).
368 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
372 * GNU make now uses automake to control Makefile.in generation. This
373 should make it more consistent with the GNU standards.
375 * VPATH functionality has been changed to incorporate the VPATH+ patch,
376 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
379 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
380 were specified on the command line, if any. Modifying this variable
381 has no effect on the operation of make.
383 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
384 list of words from number S to number E (inclusive) of TEXT.
386 * Instead of an error, detection of future modification times gives a
387 warning and continues. The warning is repeated just before GNU make
388 exits, so it is less likely to be lost.
390 * Fix the $(basename) and $(suffix) functions so they only operate on
391 the last filename, not the entire string:
393 Command Old Result New Result
394 ------- ---------- ----------
396 $(basename a.b/c) a a.b/c
398 $(suffix a.b/c) b/c <empty>
400 * The $(strip) function now removes newlines as well as TABs and spaces.
402 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
405 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
407 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
408 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
409 and utilities. See README.DOS for details, and direct all questions
410 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
411 Delorie <dj@delorie.com>.
413 * John W. Eaton has updated the VMS port to support libraries and VPATH.
417 * The directory messages printed by `-w' and implicitly in sub-makes,
418 are now omitted if Make runs no commands and has no other messages to print.
420 * Make now detects files that for whatever reason have modification times
421 in the future and gives an error. Files with such impossible timestamps
422 can result from unsynchronized clocks, or archived distributions
423 containing bogus timestamps; they confuse Make's dependency engine
426 * The new directive `sinclude' is now recognized as another name for
427 `-include', for compatibility with some other Makes.
429 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
430 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
432 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
433 See README.W32 for details, and direct all Windows-related questions to
434 <rob_tulloh@tivoli.com>.
438 * Converted to use Autoconf version 2, so `configure' has some new options.
439 See INSTALL for details.
441 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
442 output enabled by -d, at any time during the run.
446 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
447 He is maintaining the DOS port, not the GNU Make maintainer;
448 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
449 MS-DOS binaries are available for FTP from ftp.simtel.net in
450 /pub/simtelnet/gnu/djgpp/.
452 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
453 contain variable definitions itself; these are treated just like
454 command-line variable definitions. Make will automatically insert any
455 variable definitions from the environment value of `MAKEFLAGS' or from
456 the command line, into the `MAKEFLAGS' value exported to children. The
457 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
458 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
459 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
460 in the environment when its size is limited.
462 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
463 a rule if it has changed when its commands exit with a nonzero status,
464 just as when the commands get a signal.
466 * The automatic variable `$+' is new. It lists all the dependencies like
467 `$^', but preserves duplicates listed in the makefile. This is useful
468 for linking rules, where library files sometimes need to be listed twice
471 * You can now specify the `.IGNORE' and `.SILENT' special targets with
472 dependencies to limit their effects to those files. If a file appears as
473 a dependency of `.IGNORE', then errors will be ignored while running the
474 commands to update that file. Likewise if a file appears as a dependency
475 of `.SILENT', then the commands to update that file will not be printed
476 before they are run. (This change was made to conform to POSIX.2.)
480 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
481 `$(^D)' now omit the trailing slash from the directory name. (This change
482 was made to comply with POSIX.2.)
484 * The source distribution now includes the Info files for the Make manual.
485 There is no longer a separate distribution containing Info and DVI files.
487 * You can now set the variables `binprefix' and/or `manprefix' in
488 Makefile.in (or on the command line when installing) to install GNU make
489 under a name other than `make' (i.e., ``make binprefix=g install''
490 installs GNU make as `gmake').
492 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
493 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
496 * The exit status of Make when it runs into errors is now 2 instead of 1.
497 The exit status is 1 only when using -q and some target is not up to date.
498 (This change was made to comply with POSIX.2.)
502 * It is no longer a fatal error to have a NUL character in a makefile.
503 You should never put a NUL in a makefile because it can have strange
504 results, but otherwise empty lines full of NULs (such as produced by
505 the `xmkmf' program) will always work fine.
507 * The error messages for nonexistent included makefiles now refer to the
508 makefile name and line number where the `include' appeared, so Emacs's
509 C-x ` command takes you there (in case it's a typo you need to fix).
513 * Implicit rule search for archive member references is now done in the
514 opposite order from previous versions: the whole target name `LIB(MEM)'
515 first, and just the member name and parentheses `(MEM)' second.
517 * Make now gives an error for an unterminated variable or function reference.
518 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
520 * The new default variable `MAKE_VERSION' gives the version number of
521 Make, and a string describing the remote job support compiled in (if any).
522 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
524 * Commands in an invocation of the `shell' function are no longer run with
525 a modified environment like target commands are. As in versions before
526 3.68, they now run with the environment that `make' started with. We
527 have reversed the change made in version 3.68 because it turned out to
528 cause a paradoxical situation in cases like:
530 export variable = $(shell echo value)
532 When Make attempted to put this variable in the environment for a target
533 command, it would try expand the value by running the shell command
534 `echo value'. In version 3.68, because it constructed an environment
535 for that shell command in the same way, Make would begin to go into an
536 infinite loop and then get a fatal error when it detected the loop.
538 * The commands given for `.DEFAULT' are now used for phony targets with no
543 * You can list several archive member names inside parenthesis:
544 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
546 * You can use wildcards inside archive member references. For example,
547 `lib(*.o)' expands to all existing members of `lib' whose names end in
548 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
549 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
550 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
552 * A suffix rule `.X.a' now produces two pattern rules:
553 (%.o): %.X # Previous versions produced only this.
554 %.a: %.X # Now produces this as well, just like other suffixes.
556 * The new flag `--warn-undefined-variables' says to issue a warning message
557 whenever Make expands a reference to an undefined variable.
559 * The new `-include' directive is just like `include' except that there is
560 no error (not even a warning) for a nonexistent makefile.
562 * Commands in an invocation of the `shell' function are now run with a
563 modified environment like target commands are, so you can use `export' et
564 al to set up variables for them. They used to run with the environment
565 that `make' started with.
569 * `make --version' (or `make -v') now exits immediately after printing
574 * Make now supports long-named members in `ar' archive files.
578 * Make now supports the `+=' syntax for a variable definition which appends
579 to the variable's previous value. See the section `Appending More Text
580 to Variables' in the manual for full details.
582 * The new option `--no-print-directory' inhibits the `-w' or
583 `--print-directory' feature. Make turns on `--print-directory'
584 automatically if you use `-C' or `--directory', and in sub-makes; some
585 users have found this behavior undesirable.
587 * The built-in implicit rules now support the alternative extension
588 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
592 * Make now uses a standard GNU `configure' script. See the new file
593 INSTALL for the new (and much simpler) installation procedure.
595 * There is now a shell script to build Make the first time, if you have no
596 other `make' program. `build.sh' is created by `configure'; see README.
598 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
600 * Elements of the `$^' and `$?' automatic variables that are archive
601 member references now list only the member name, as in Unix and POSIX.2.
603 * You should no longer ever need to specify the `-w' switch, which prints
604 the current directory before and after Make runs. The `-C' switch to
605 change directory, and recursive use of Make, now set `-w' automatically.
607 * Multiple double-colon rules for the same target will no longer have their
608 commands run simultaneously under -j, as this could result in the two
609 commands trying to change the file at the same time and interfering with
612 * The `SHELL' variable is now never taken from the environment.
613 Each makefile that wants a shell other than the default (/bin/sh) must
614 set SHELL itself. SHELL is always exported to child processes.
615 This change was made for compatibility with POSIX.2.
617 * Make now accepts long options. There is now an informative usage message
618 that tells you what all the options are and what they do. Try `make --help'.
620 * There are two new directives: `export' and `unexport'. All variables are
621 no longer automatically put into the environments of the commands that
622 Make runs. Instead, only variables specified on the command line or in
623 the environment are exported by default. To export others, use:
625 or you can define variables with:
626 export VARIABLE = VALUE
628 export VARIABLE := VALUE
632 .EXPORT_ALL_VARIABLES:
633 to get the old behavior. See the node `Variables/Recursion' in the manual
634 for a full description.
636 * The commands from the `.DEFAULT' special target are only applied to
637 targets which have no rules at all, not all targets with no commands.
638 This change was made for compatibility with Unix make.
640 * All fatal error messages now contain `***', so they are easy to find in
643 * Dependency file names like `-lNAME' are now replaced with the actual file
644 name found, as with files found by normal directory search (VPATH).
645 The library file `libNAME.a' may now be found in the current directory,
646 which is checked before VPATH; the standard set of directories (/lib,
647 /usr/lib, /usr/local/lib) is now checked last.
648 See the node `Libraries/Search' in the manual for full details.
650 * A single `include' directive can now specify more than one makefile to
653 You can also use shell file name patterns in an `include' directive:
656 * The default directories to search for included makefiles, and for
657 libraries specified with `-lNAME', are now set by configuration.
659 * You can now use blanks as well as colons to separate the directories in a
660 search path for the `vpath' directive or the `VPATH' variable.
662 * You can now use variables and functions in the left hand side of a
663 variable assignment, as in "$(foo)bar = value".
665 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
666 The `MAKE_COMMAND' variable is now defined to the name with which make
669 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
670 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
671 problems with shells that cannot have `+' in environment variable names.
673 * The value of a recursively expanded variable is now expanded when putting
674 it into the environment for child processes. This change was made for
675 compatibility with Unix make.
677 * A rule with no targets before the `:' is now accepted and ignored.
678 This change was made for compatibility with SunOS 4 make.
679 We do not recommend that you write your makefiles to take advantage of this.
681 * The `-I' switch can now be used in MAKEFLAGS, and are put there
682 automatically just like other switches.
686 * Built-in rules for C++ source files with the `.C' suffix.
687 We still recommend that you use `.cc' instead.
689 * If commands are given too many times for a single target,
690 the last set given is used, and a warning message is printed.
692 * Error messages about makefiles are in standard GNU error format,
693 so C-x ` in Emacs works on them.
695 * Dependencies of pattern rules which contain no % need not actually exist
696 if they can be created (just like dependencies which do have a %).
700 * A message is always printed when Make decides there is nothing to be done.
701 It used to be that no message was printed for top-level phony targets
702 (because "`phony' is up to date" isn't quite right). Now a different
703 message "Nothing to be done for `phony'" is printed in that case.
705 * Archives on AIX now supposedly work.
707 * When the commands specified for .DEFAULT are used to update a target,
708 the $< automatic variable is given the same value as $@ for that target.
709 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
713 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
714 variables while remaking makefiles, so recursive makes done while remaking
715 makefiles will behave properly.
717 * If the special target `.NOEXPORT' is specified in a makefile,
718 only variables that came from the environment and variables
719 defined on the command line are exported.
723 * Suffix rules may have dependencies (which are ignored).
727 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
728 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
732 * There is now a Unix man page for GNU Make. It is certainly not a replacement
733 for the Texinfo manual, but it documents the basic functionality and the
734 switches. For full documentation, you should still read the Texinfo manual.
735 Thanks to Dennis Morse of Stanford University for contributing the initial
738 * Variables which are defined by default (e.g., `CC') will no longer be put
739 into the environment for child processes. (If these variables are reset by the
740 environment, makefiles, or the command line, they will still go into the
743 * Makefiles which have commands but no dependencies (and thus are always
744 considered out of date and in need of remaking), will not be remade (if they
745 were being remade only because they were makefiles). This means that GNU
746 Make will no longer go into an infinite loop when fed the makefiles that
747 `imake' (necessary to build X Windows) produces.
749 * There is no longer a warning for using the `vpath' directive with an explicit
750 pathname (instead of a `%' pattern).
754 * When removing intermediate files, only one `rm' command line is printed,
755 listing all file names.
757 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
758 These are the directory-only and file-only versions of `$^' and `$?'.
760 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
761 directory if it exists.
763 * The automatic variable `$($/)' is no longer defined.
765 * Leading `+' characters on a command line make that line be executed even
766 under -n, -t, or -q (as if the line contained `$(MAKE)').
768 * For command lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
769 only those lines are executed, not their entire rules.
770 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
774 * Filenames in rules will now have ~ and ~USER expanded.
776 * The `-p' output has been changed so it can be used as a makefile.
777 (All information that isn't specified by makefiles is prefaced with comment
782 * The % character can be quoted with backslash in implicit pattern rules,
783 static pattern rules, `vpath' directives, and `patsubst', `filter', and
784 `filter-out' functions. A warning is issued if a `vpath' directive's
785 pattern contains no %.
787 * The `wildcard' variable expansion function now expands ~ and ~USER.
789 * Messages indicating failed commands now contain the target name:
790 make: *** [target] Error 1
792 * The `-p' output format has been changed somewhat to look more like
793 makefile rules and to give all information that Make has about files.
799 * The `-l' switch with no argument removes any previous load-average limit.
801 * When the `-w' switch is in effect, and Make has updated makefiles,
802 it will write a `Leaving directory' messagfe before re-executing itself.
803 This makes the `directory change tracking' changes to Emacs's compilation
804 commands work properly.
808 * The automatic variable `$*' is now defined for explicit rules,
809 as it is in Unix make.
813 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
814 specified without an argument (indicating infinite jobs).
815 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
817 * Make no longer checks hashed directories after running commands.
818 The behavior implemented in 3.41 caused too much slowdown.
822 * A dependency is NOT considered newer than its dependent if
823 they have the same modification time. The behavior implemented
824 in 3.43 conflicts with RCS.
828 * Dependency loops are no longer fatal errors.
830 * A dependency is considered newer than its dependent if
831 they have the same modification time.
835 * The variables F77 and F77FLAGS are now set by default to $(FC) and
836 $(FFLAGS). Makefiles designed for System V make may use these variables in
837 explicit rules and expect them to be set. Unfortunately, there is no way to
838 make setting these affect the Fortran implicit rules unless FC and FFLAGS
839 are not used (and these are used by BSD make).
843 * Make now checks to see if its hashed directories are changed by commands.
844 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
848 * The `shell' function no longer captures standard error output.
852 * A file beginning with a dot can be the default target if it also contains
853 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
857 * Archive member names are truncated to 15 characters.
859 * Yet more USG stuff.
861 * Minimal support for Microport System V (a 16-bit machine and a
862 brain-damaged compiler). This has even lower priority than other USG
863 support, so if it gets beyond trivial, I will take it out completely.
865 * Revamped default implicit rules (not much visible change).
867 * The -d and -p options can come from the environment.
871 * Improved support for USG and HPUX (hopefully).
873 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
874 equivalent to `$(patsubst a,b,$(foo))'.
876 * Defining .DEFAULT with no deps or commands clears its commands.
878 * New default implicit rules for .S (cpp, then as), and .sh (copy and make
879 executable). All default implicit rules that use cpp (even indirectly), use
884 * Giving the -j option with no arguments gives you infinite jobs.
888 * New option: "-l LOAD" says not to start any new jobs while others are
889 running if the load average is not below LOAD (a floating-point number).
891 * There is support in place for implementations of remote command execution
892 in Make. See the file remote.c.
896 * No more than 10 directories will be kept open at once.
897 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
901 * Archive files will have their modification times recorded before doing
902 anything that might change their modification times by updating an archive
907 * The `MAKELEVEL' variable is defined for use by makefiles.
911 * The recursion level indications in error messages are much shorter than
912 they were in version 3.14.
916 * Leading spaces before directives are ignored (as documented).
918 * Included makefiles can determine the default goal target.
919 (System V Make does it this way, so we are being compatible).
923 * Variables that are defaults built into Make will not be put in the
924 environment for children. This just saves some environment space and,
925 except under -e, will be transparent to sub-makes.
927 * Error messages from sub-makes will indicate the level of recursion.
929 * Hopefully some speed-up for large directories due to a change in the
930 directory hashing scheme.
932 * One child will always get a standard input that is usable.
934 * Default makefiles that don't exist will be remade and read in.
938 * Count parentheses inside expansion function calls so you can
939 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
943 * Several bug fixes, including USG and Sun386i support.
945 * `shell' function to expand shell commands a la `
947 * If the `-d' flag is given, version information will be printed.
949 * The `-c' option has been renamed to `-C' for compatibility with tar.
951 * The `-p' option no longer inhibits other normal operation.
953 * Makefiles will be updated and re-read if necessary.
955 * Can now run several commands at once (parallelism), -j option.
957 * Error messages will contain the level of Make recursion, if any.
959 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
962 * A double-colon rule with no dependencies will always have its commands run.
963 (This is how both the BSD and System V versions of Make do it.)
967 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
969 ----------------------------------------------------------------------
970 Copyright information:
972 Permission is granted to anyone to make or distribute verbatim copies
973 of this document as received, in any medium, provided that the
974 copyright notice and this permission notice are preserved, thus
975 giving the recipient permission to redistribute in turn.
977 Permission is granted to distribute modified versions of this
978 document, or of portions of it, under the above conditions, provided
979 also that they carry prominent notices stating who last changed them.