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.
98 - $(or ...) provides a short-circuiting OR conditional: each argument
99 is expanded. The first true (non-empty) argument is returned; no
100 further arguments are expanded. Expands to empty if there are no
102 - $(and ...) provides a short-circuiting AND conditional: each
103 argument is expanded. The first false (empty) argument is
104 returned; no further arguments are expanded. Expands to the last
105 argument if all arguments are true.
107 * Changes made for POSIX compatibility:
108 - Only touch targets (under -t) if they have at least one command.
109 - Setting the SHELL make variable does NOT change the value of the
110 SHELL environment variable given to programs invoked by make. As
111 an enhancement to POSIX, if you export the make variable SHELL then
112 it will be set in the environment, just as before.
114 * On MS Windows systems, explicitly setting SHELL to a pathname ending
115 in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use
116 the DOS command interpreter in batch mode even if a UNIX-like shell
117 could be found on the system.
119 * On VMS there is now support for case-sensitive filesystems such as ODS5.
120 See the readme.vms file for information.
122 * Parallel builds (-jN) no longer require a working Bourne shell on
123 Windows platforms. They work even with the stock Windows shells, such
124 as cmd.exe and command.com.
126 * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users
127 should not be impacted.
129 * New translations for Swedish, Chinese (simplified), Ukrainian,
130 Belarusian, Finnish, Kinyarwandan, and Irish. Many updated
133 A complete list of bugs fixed in this version is available here:
135 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=101
140 * A new feature exists: order-only prerequisites. These prerequisites
141 affect the order in which targets are built, but they do not impact
142 the rebuild/no-rebuild decision of their dependents. That is to say,
143 they allow you to require target B be built before target A, without
144 requiring that target A will always be rebuilt if target B is updated.
145 Patch for this feature provided by Greg McGary <greg@mcgary.org>.
147 * For compatibility with SysV make, GNU make now supports the peculiar
148 syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule.
149 This syntax is only valid within explicit and static pattern rules: it
150 cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan
151 <egp@free.fr> provided a patch implementing this feature; however, I
152 decided to implement it in a different way.
154 * The argument to the "ifdef" conditional is now expanded before it's
155 tested, so it can be a constructed variable name.
157 Similarly, the arguments to "export" (when not used in a variable
158 definition context) and "unexport" are also now expanded.
160 * A new function is defined: $(value ...). The argument to this
161 function is the _name_ of a variable. The result of the function is
162 the value of the variable, without having been expanded.
164 * A new function is defined: $(eval ...). The arguments to this
165 function should expand to makefile commands, which will then be
166 evaluated as if they had appeared in the makefile. In combination
167 with define/endef multiline variable definitions this is an extremely
168 powerful capability. The $(value ...) function is also sometimes
171 * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a
172 list of each makefile GNU make has read, or started to read, in the
173 order in which they were encountered. So, the last filename in the
174 list when a makefile is just being read (before any includes) is the
175 name of the current makefile.
177 * A new built-in variable is defined: $(.VARIABLES). When it is
178 expanded it returns a complete list of variable names defined by all
179 makefiles at that moment.
181 * A new command-line option is defined, -B or --always-make. If
182 specified GNU make will consider all targets out-of-date even if they
183 would otherwise not be.
185 * The arguments to $(call ...) functions were being stored in $1, $2,
186 etc. as recursive variables, even though they are fully expanded
187 before assignment. This means that escaped dollar signs ($$ etc.)
188 were not behaving properly. Now the arguments are stored as simple
189 variables. This may mean that if you added extra escaping to your
190 $(call ...) function arguments you will need to undo it now.
192 * The variable invoked by $(call ...) can now be recursive: unlike other
193 variables it can reference itself and this will not produce an error
194 when it is used as the first argument to $(call ...) (but only then).
196 * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure
197 option --disable-nsec-timestamps. You might need this if your build
198 process depends on tools like "cp -p" preserving time stamps, since
199 "cp -p" (right now) doesn't preserve the subsecond portion of a time
202 * Updated translations for French, Galician, German, Japanese, Korean,
203 and Russian. New translations for Croatian, Danish, Hebrew, and
206 * Updated internationalization support to Gettext 0.11.5.
207 GNU make now uses Gettext's "external" feature, and does not include
208 any internationalization code itself. Configure will search your
209 system for an existing implementation of GNU Gettext (only GNU Gettext
210 is acceptable) and use it if it exists. If not, NLS will be disabled.
211 See ABOUT-NLS for more information.
213 * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted.
215 A complete list of bugs fixed in this version is available here:
217 http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102
222 * .SECONDARY with no prerequisites now prevents any target from being
223 removed because make thinks it's an intermediate file, not just those
224 listed in the makefile.
226 * New configure option --disable-nsec-timestamps, but this was
227 superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target.
231 * GNU make optionally supports internationalization and locales via the
232 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
233 file for more information on configuring GNU make for NLS.
235 * Previously, GNU make quoted variables such as MAKEFLAGS and
236 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
237 be used within make build scripts. However, using them there is not
238 proper behavior: they are meant to be passed to subshells via the
239 environment. Unfortunately the values were not quoted properly to be
240 passed through the environment. This meant that make didn't properly
241 pass some types of command line values to submakes.
243 With this version we change that behavior: now these variables are
244 quoted properly for passing through the environment, which is the
245 correct way to do it. If you previously used these variables
246 explicitly within a make rule you may need to re-examine your use for
247 correctness given this change.
249 * A new pseudo-target .NOTPARALLEL is available. If defined, the
250 current makefile is run serially regardless of the value of -j.
251 However, submakes are still eligible for parallel execution.
253 * The --debug option has changed: it now allows optional flags
254 controlling the amount and type of debugging output. By default only
255 a minimal amount information is generated, displaying the names of
256 "normal" targets (not makefiles) that were deemed out of date and in
257 need of being rebuilt.
259 Note that the -d option behaves as before: it takes no arguments and
260 all debugging information is generated.
262 * The `-p' (print database) output now includes filename and linenumber
263 information for variable definitions, to aid debugging.
265 * The wordlist function no longer reverses its arguments if the "start"
266 value is greater than the "end" value. If that's true, nothing is
269 * Hartmut Becker provided many updates for the VMS port of GNU make.
270 See the readme.vms file for more details.
274 * Two new functions, $(error ...) and $(warning ...) are available. The
275 former will cause make to fail and exit immediately upon expansion of
276 the function, with the text provided as the error message. The latter
277 causes the text provided to be printed as a warning message, but make
280 * A new function $(call ...) is available. This allows users to create
281 their own parameterized macros and invoke them later. Original
282 implementation of this function was provided by Han-Wen Nienhuys
285 * A new function $(if ...) is available. It provides if-then-else
286 capabilities in a builtin function. Original implementation of this
287 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
289 * Make defines a new variable, .LIBPATTERNS. This variable controls how
290 library dependency expansion (dependencies like ``-lfoo'') is performed.
292 * Make accepts CRLF sequences as well as traditional LF, for
293 compatibility with makefiles created on other operating systems.
295 * Make accepts a new option: -R, or --no-builtin-variables. This option
296 disables the definition of the rule-specific builtin variables (CC,
297 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
300 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
302 On systems that support POSIX pipe(2) semantics, GNU make can now pass
303 -jN options to submakes rather than forcing them all to use -j1. The
304 top make and all its sub-make processes use a pipe to communicate with
305 each other to ensure that no more than N jobs are started across all
306 makes. To get the old behavior of -j back, you can configure make
307 with the --disable-job-server option.
309 * The confusing term "dependency" has been replaced by the more accurate
310 and standard term "prerequisite", both in the manual and in all GNU make
313 * GNU make supports the "big archive" library format introduced in AIX 4.3.
315 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
316 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
317 support for Solaris and Linux was introduced in 3.77, but the
318 configuration had issues: these have also been resolved).
320 * The Windows 95/98/NT (W32) version of GNU make now has native support
321 for the Cygnus Cygwin release B20.1 shell (bash).
323 * The GNU make regression test suite, long available separately "under
324 the table", has been integrated into the release. You can invoke it
325 by running "make check" in the distribution. Note that it requires
326 Perl (either Perl 4 or Perl 5) to run.
330 * Implement BSD make's "?=" variable assignment operator. The variable
331 is assigned the specified value only if that variable is not already
334 * Make defines a new variable, "CURDIR", to contain the current working
335 directory (after the -C option, if any, has been processed).
336 Modifying this variable has no effect on the operation of make.
338 * Make defines a new default RCS rule, for new-style master file
339 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
341 Make defines new default rules for DOS-style C++ file naming
342 conventions, with ``.cpp'' suffixes. All the same rules as for
343 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
344 COMPILE.cpp macros (which default to the same value as LINK.cc and
345 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
346 use CXXFLAGS to change C++ compiler flags.
348 * A new feature, "target-specific variable values", has been added.
349 This is a large change so please see the appropriate sections of the
350 manual for full details. Briefly, syntax like this:
352 TARGET: VARIABLE = VALUE
354 defines VARIABLE as VALUE within the context of TARGET. This is
355 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
356 that the assignment may be of any type, not just recursive, and that
357 the override keyword is available.
359 COMPATIBILITY: This new syntax means that if you have any rules where
360 the first or second dependency has an equal sign (=) in its name,
361 you'll have to escape them with a backslash: "foo : bar\=baz".
362 Further, if you have any dependencies which already contain "\=",
363 you'll have to escape both of them: "foo : bar\\\=baz".
365 * A new appendix listing the most common error and warning messages
366 generated by GNU make, with some explanation, has been added to the
367 GNU make User's Manual.
369 * Updates to the GNU make Customs library support (see README.customs).
371 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
372 and to the DOS port from Eli Zaretski (see README.DOS).
376 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
380 * GNU make now uses automake to control Makefile.in generation. This
381 should make it more consistent with the GNU standards.
383 * VPATH functionality has been changed to incorporate the VPATH+ patch,
384 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
387 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
388 were specified on the command line, if any. Modifying this variable
389 has no effect on the operation of make.
391 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
392 list of words from number S to number E (inclusive) of TEXT.
394 * Instead of an error, detection of future modification times gives a
395 warning and continues. The warning is repeated just before GNU make
396 exits, so it is less likely to be lost.
398 * Fix the $(basename) and $(suffix) functions so they only operate on
399 the last filename, not the entire string:
401 Command Old Result New Result
402 ------- ---------- ----------
404 $(basename a.b/c) a a.b/c
406 $(suffix a.b/c) b/c <empty>
408 * The $(strip) function now removes newlines as well as TABs and spaces.
410 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
413 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
415 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
416 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
417 and utilities. See README.DOS for details, and direct all questions
418 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
419 Delorie <dj@delorie.com>.
421 * John W. Eaton has updated the VMS port to support libraries and VPATH.
425 * The directory messages printed by `-w' and implicitly in sub-makes,
426 are now omitted if Make runs no commands and has no other messages to print.
428 * Make now detects files that for whatever reason have modification times
429 in the future and gives an error. Files with such impossible timestamps
430 can result from unsynchronized clocks, or archived distributions
431 containing bogus timestamps; they confuse Make's dependency engine
434 * The new directive `sinclude' is now recognized as another name for
435 `-include', for compatibility with some other Makes.
437 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
438 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
440 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
441 See README.W32 for details, and direct all Windows-related questions to
442 <rob_tulloh@tivoli.com>.
446 * Converted to use Autoconf version 2, so `configure' has some new options.
447 See INSTALL for details.
449 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
450 output enabled by -d, at any time during the run.
454 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
455 He is maintaining the DOS port, not the GNU Make maintainer;
456 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
457 MS-DOS binaries are available for FTP from ftp.simtel.net in
458 /pub/simtelnet/gnu/djgpp/.
460 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
461 contain variable definitions itself; these are treated just like
462 command-line variable definitions. Make will automatically insert any
463 variable definitions from the environment value of `MAKEFLAGS' or from
464 the command line, into the `MAKEFLAGS' value exported to children. The
465 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
466 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
467 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
468 in the environment when its size is limited.
470 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
471 a rule if it has changed when its commands exit with a nonzero status,
472 just as when the commands get a signal.
474 * The automatic variable `$+' is new. It lists all the dependencies like
475 `$^', but preserves duplicates listed in the makefile. This is useful
476 for linking rules, where library files sometimes need to be listed twice
479 * You can now specify the `.IGNORE' and `.SILENT' special targets with
480 dependencies to limit their effects to those files. If a file appears as
481 a dependency of `.IGNORE', then errors will be ignored while running the
482 commands to update that file. Likewise if a file appears as a dependency
483 of `.SILENT', then the commands to update that file will not be printed
484 before they are run. (This change was made to conform to POSIX.2.)
488 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
489 `$(^D)' now omit the trailing slash from the directory name. (This change
490 was made to comply with POSIX.2.)
492 * The source distribution now includes the Info files for the Make manual.
493 There is no longer a separate distribution containing Info and DVI files.
495 * You can now set the variables `binprefix' and/or `manprefix' in
496 Makefile.in (or on the command line when installing) to install GNU make
497 under a name other than `make' (i.e., ``make binprefix=g install''
498 installs GNU make as `gmake').
500 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
501 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
504 * The exit status of Make when it runs into errors is now 2 instead of 1.
505 The exit status is 1 only when using -q and some target is not up to date.
506 (This change was made to comply with POSIX.2.)
510 * It is no longer a fatal error to have a NUL character in a makefile.
511 You should never put a NUL in a makefile because it can have strange
512 results, but otherwise empty lines full of NULs (such as produced by
513 the `xmkmf' program) will always work fine.
515 * The error messages for nonexistent included makefiles now refer to the
516 makefile name and line number where the `include' appeared, so Emacs's
517 C-x ` command takes you there (in case it's a typo you need to fix).
521 * Implicit rule search for archive member references is now done in the
522 opposite order from previous versions: the whole target name `LIB(MEM)'
523 first, and just the member name and parentheses `(MEM)' second.
525 * Make now gives an error for an unterminated variable or function reference.
526 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
528 * The new default variable `MAKE_VERSION' gives the version number of
529 Make, and a string describing the remote job support compiled in (if any).
530 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
532 * Commands in an invocation of the `shell' function are no longer run with
533 a modified environment like target commands are. As in versions before
534 3.68, they now run with the environment that `make' started with. We
535 have reversed the change made in version 3.68 because it turned out to
536 cause a paradoxical situation in cases like:
538 export variable = $(shell echo value)
540 When Make attempted to put this variable in the environment for a target
541 command, it would try expand the value by running the shell command
542 `echo value'. In version 3.68, because it constructed an environment
543 for that shell command in the same way, Make would begin to go into an
544 infinite loop and then get a fatal error when it detected the loop.
546 * The commands given for `.DEFAULT' are now used for phony targets with no
551 * You can list several archive member names inside parenthesis:
552 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
554 * You can use wildcards inside archive member references. For example,
555 `lib(*.o)' expands to all existing members of `lib' whose names end in
556 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
557 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
558 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
560 * A suffix rule `.X.a' now produces two pattern rules:
561 (%.o): %.X # Previous versions produced only this.
562 %.a: %.X # Now produces this as well, just like other suffixes.
564 * The new flag `--warn-undefined-variables' says to issue a warning message
565 whenever Make expands a reference to an undefined variable.
567 * The new `-include' directive is just like `include' except that there is
568 no error (not even a warning) for a nonexistent makefile.
570 * Commands in an invocation of the `shell' function are now run with a
571 modified environment like target commands are, so you can use `export' et
572 al to set up variables for them. They used to run with the environment
573 that `make' started with.
577 * `make --version' (or `make -v') now exits immediately after printing
582 * Make now supports long-named members in `ar' archive files.
586 * Make now supports the `+=' syntax for a variable definition which appends
587 to the variable's previous value. See the section `Appending More Text
588 to Variables' in the manual for full details.
590 * The new option `--no-print-directory' inhibits the `-w' or
591 `--print-directory' feature. Make turns on `--print-directory'
592 automatically if you use `-C' or `--directory', and in sub-makes; some
593 users have found this behavior undesirable.
595 * The built-in implicit rules now support the alternative extension
596 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
600 * Make now uses a standard GNU `configure' script. See the new file
601 INSTALL for the new (and much simpler) installation procedure.
603 * There is now a shell script to build Make the first time, if you have no
604 other `make' program. `build.sh' is created by `configure'; see README.
606 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
608 * Elements of the `$^' and `$?' automatic variables that are archive
609 member references now list only the member name, as in Unix and POSIX.2.
611 * You should no longer ever need to specify the `-w' switch, which prints
612 the current directory before and after Make runs. The `-C' switch to
613 change directory, and recursive use of Make, now set `-w' automatically.
615 * Multiple double-colon rules for the same target will no longer have their
616 commands run simultaneously under -j, as this could result in the two
617 commands trying to change the file at the same time and interfering with
620 * The `SHELL' variable is now never taken from the environment.
621 Each makefile that wants a shell other than the default (/bin/sh) must
622 set SHELL itself. SHELL is always exported to child processes.
623 This change was made for compatibility with POSIX.2.
625 * Make now accepts long options. There is now an informative usage message
626 that tells you what all the options are and what they do. Try `make --help'.
628 * There are two new directives: `export' and `unexport'. All variables are
629 no longer automatically put into the environments of the commands that
630 Make runs. Instead, only variables specified on the command line or in
631 the environment are exported by default. To export others, use:
633 or you can define variables with:
634 export VARIABLE = VALUE
636 export VARIABLE := VALUE
640 .EXPORT_ALL_VARIABLES:
641 to get the old behavior. See the node `Variables/Recursion' in the manual
642 for a full description.
644 * The commands from the `.DEFAULT' special target are only applied to
645 targets which have no rules at all, not all targets with no commands.
646 This change was made for compatibility with Unix make.
648 * All fatal error messages now contain `***', so they are easy to find in
651 * Dependency file names like `-lNAME' are now replaced with the actual file
652 name found, as with files found by normal directory search (VPATH).
653 The library file `libNAME.a' may now be found in the current directory,
654 which is checked before VPATH; the standard set of directories (/lib,
655 /usr/lib, /usr/local/lib) is now checked last.
656 See the node `Libraries/Search' in the manual for full details.
658 * A single `include' directive can now specify more than one makefile to
661 You can also use shell file name patterns in an `include' directive:
664 * The default directories to search for included makefiles, and for
665 libraries specified with `-lNAME', are now set by configuration.
667 * You can now use blanks as well as colons to separate the directories in a
668 search path for the `vpath' directive or the `VPATH' variable.
670 * You can now use variables and functions in the left hand side of a
671 variable assignment, as in "$(foo)bar = value".
673 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
674 The `MAKE_COMMAND' variable is now defined to the name with which make
677 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
678 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
679 problems with shells that cannot have `+' in environment variable names.
681 * The value of a recursively expanded variable is now expanded when putting
682 it into the environment for child processes. This change was made for
683 compatibility with Unix make.
685 * A rule with no targets before the `:' is now accepted and ignored.
686 This change was made for compatibility with SunOS 4 make.
687 We do not recommend that you write your makefiles to take advantage of this.
689 * The `-I' switch can now be used in MAKEFLAGS, and are put there
690 automatically just like other switches.
694 * Built-in rules for C++ source files with the `.C' suffix.
695 We still recommend that you use `.cc' instead.
697 * If commands are given too many times for a single target,
698 the last set given is used, and a warning message is printed.
700 * Error messages about makefiles are in standard GNU error format,
701 so C-x ` in Emacs works on them.
703 * Dependencies of pattern rules which contain no % need not actually exist
704 if they can be created (just like dependencies which do have a %).
708 * A message is always printed when Make decides there is nothing to be done.
709 It used to be that no message was printed for top-level phony targets
710 (because "`phony' is up to date" isn't quite right). Now a different
711 message "Nothing to be done for `phony'" is printed in that case.
713 * Archives on AIX now supposedly work.
715 * When the commands specified for .DEFAULT are used to update a target,
716 the $< automatic variable is given the same value as $@ for that target.
717 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
721 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
722 variables while remaking makefiles, so recursive makes done while remaking
723 makefiles will behave properly.
725 * If the special target `.NOEXPORT' is specified in a makefile,
726 only variables that came from the environment and variables
727 defined on the command line are exported.
731 * Suffix rules may have dependencies (which are ignored).
735 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
736 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
740 * There is now a Unix man page for GNU Make. It is certainly not a replacement
741 for the Texinfo manual, but it documents the basic functionality and the
742 switches. For full documentation, you should still read the Texinfo manual.
743 Thanks to Dennis Morse of Stanford University for contributing the initial
746 * Variables which are defined by default (e.g., `CC') will no longer be put
747 into the environment for child processes. (If these variables are reset by the
748 environment, makefiles, or the command line, they will still go into the
751 * Makefiles which have commands but no dependencies (and thus are always
752 considered out of date and in need of remaking), will not be remade (if they
753 were being remade only because they were makefiles). This means that GNU
754 Make will no longer go into an infinite loop when fed the makefiles that
755 `imake' (necessary to build X Windows) produces.
757 * There is no longer a warning for using the `vpath' directive with an explicit
758 pathname (instead of a `%' pattern).
762 * When removing intermediate files, only one `rm' command line is printed,
763 listing all file names.
765 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
766 These are the directory-only and file-only versions of `$^' and `$?'.
768 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
769 directory if it exists.
771 * The automatic variable `$($/)' is no longer defined.
773 * Leading `+' characters on a command line make that line be executed even
774 under -n, -t, or -q (as if the line contained `$(MAKE)').
776 * For command lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
777 only those lines are executed, not their entire rules.
778 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
782 * Filenames in rules will now have ~ and ~USER expanded.
784 * The `-p' output has been changed so it can be used as a makefile.
785 (All information that isn't specified by makefiles is prefaced with comment
790 * The % character can be quoted with backslash in implicit pattern rules,
791 static pattern rules, `vpath' directives, and `patsubst', `filter', and
792 `filter-out' functions. A warning is issued if a `vpath' directive's
793 pattern contains no %.
795 * The `wildcard' variable expansion function now expands ~ and ~USER.
797 * Messages indicating failed commands now contain the target name:
798 make: *** [target] Error 1
800 * The `-p' output format has been changed somewhat to look more like
801 makefile rules and to give all information that Make has about files.
807 * The `-l' switch with no argument removes any previous load-average limit.
809 * When the `-w' switch is in effect, and Make has updated makefiles,
810 it will write a `Leaving directory' messagfe before re-executing itself.
811 This makes the `directory change tracking' changes to Emacs's compilation
812 commands work properly.
816 * The automatic variable `$*' is now defined for explicit rules,
817 as it is in Unix make.
821 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
822 specified without an argument (indicating infinite jobs).
823 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
825 * Make no longer checks hashed directories after running commands.
826 The behavior implemented in 3.41 caused too much slowdown.
830 * A dependency is NOT considered newer than its dependent if
831 they have the same modification time. The behavior implemented
832 in 3.43 conflicts with RCS.
836 * Dependency loops are no longer fatal errors.
838 * A dependency is considered newer than its dependent if
839 they have the same modification time.
843 * The variables F77 and F77FLAGS are now set by default to $(FC) and
844 $(FFLAGS). Makefiles designed for System V make may use these variables in
845 explicit rules and expect them to be set. Unfortunately, there is no way to
846 make setting these affect the Fortran implicit rules unless FC and FFLAGS
847 are not used (and these are used by BSD make).
851 * Make now checks to see if its hashed directories are changed by commands.
852 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
856 * The `shell' function no longer captures standard error output.
860 * A file beginning with a dot can be the default target if it also contains
861 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
865 * Archive member names are truncated to 15 characters.
867 * Yet more USG stuff.
869 * Minimal support for Microport System V (a 16-bit machine and a
870 brain-damaged compiler). This has even lower priority than other USG
871 support, so if it gets beyond trivial, I will take it out completely.
873 * Revamped default implicit rules (not much visible change).
875 * The -d and -p options can come from the environment.
879 * Improved support for USG and HPUX (hopefully).
881 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
882 equivalent to `$(patsubst a,b,$(foo))'.
884 * Defining .DEFAULT with no deps or commands clears its commands.
886 * New default implicit rules for .S (cpp, then as), and .sh (copy and make
887 executable). All default implicit rules that use cpp (even indirectly), use
892 * Giving the -j option with no arguments gives you infinite jobs.
896 * New option: "-l LOAD" says not to start any new jobs while others are
897 running if the load average is not below LOAD (a floating-point number).
899 * There is support in place for implementations of remote command execution
900 in Make. See the file remote.c.
904 * No more than 10 directories will be kept open at once.
905 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
909 * Archive files will have their modification times recorded before doing
910 anything that might change their modification times by updating an archive
915 * The `MAKELEVEL' variable is defined for use by makefiles.
919 * The recursion level indications in error messages are much shorter than
920 they were in version 3.14.
924 * Leading spaces before directives are ignored (as documented).
926 * Included makefiles can determine the default goal target.
927 (System V Make does it this way, so we are being compatible).
931 * Variables that are defaults built into Make will not be put in the
932 environment for children. This just saves some environment space and,
933 except under -e, will be transparent to sub-makes.
935 * Error messages from sub-makes will indicate the level of recursion.
937 * Hopefully some speed-up for large directories due to a change in the
938 directory hashing scheme.
940 * One child will always get a standard input that is usable.
942 * Default makefiles that don't exist will be remade and read in.
946 * Count parentheses inside expansion function calls so you can
947 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
951 * Several bug fixes, including USG and Sun386i support.
953 * `shell' function to expand shell commands a la `
955 * If the `-d' flag is given, version information will be printed.
957 * The `-c' option has been renamed to `-C' for compatibility with tar.
959 * The `-p' option no longer inhibits other normal operation.
961 * Makefiles will be updated and re-read if necessary.
963 * Can now run several commands at once (parallelism), -j option.
965 * Error messages will contain the level of Make recursion, if any.
967 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
970 * A double-colon rule with no dependencies will always have its commands run.
971 (This is how both the BSD and System V versions of Make do it.)
975 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
977 ----------------------------------------------------------------------
978 Copyright information:
980 Permission is granted to anyone to make or distribute verbatim copies
981 of this document as received, in any medium, provided that the
982 copyright notice and this permission notice are preserved, thus
983 giving the recipient permission to redistribute in turn.
985 Permission is granted to distribute modified versions of this
986 document, or of portions of it, under the above conditions, provided
987 also that they carry prominent notices stating who last changed them.