1 GNU make NEWS -*-indented-text-*-
2 History of user-visible changes.
5 Copyright (C) 1992,93,94,95,96,97,98,99,2000 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 make.texinfo.
11 Please send GNU make bug reports to <bug-make@gnu.org>.
12 See the README file and the GNU make manual for details on sending bug
17 * .SECONDARY with no prerequisites now prevents any target from being
18 removed because make thinks it's an intermediate file, not just those
19 listed in the makefile.
21 * New configure option --disable-nsec-timestamps will keep make from
22 using sub-second timestamps on systems which support it. If your
23 build process depends on proper timestamp-preserving behavior of tools
24 like "cp -p" you might need this option, since "cp -p" (right now)
25 doesn't preserve the sub-second portion of the timestamp.
29 * GNU make optionally supports internationalization and locales via the
30 GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS
31 file for more information on configuring GNU make for NLS.
33 * Previously, GNU make quoted variables such as MAKEFLAGS and
34 MAKEOVERRIDES for proper parsing by the shell. This allowed them to
35 be used within make build scripts. However, using them there is not
36 proper behavior: they are meant to be passed to subshells via the
37 environment. Unfortunately the values were not quoted properly to be
38 passed through the environment. This meant that make didn't properly
39 pass some types of command line values to submakes.
41 With this version we change that behavior: now these variables are
42 quoted properly for passing through the environment, which is the
43 correct way to do it. If you previously used these variables
44 explicitly within a make rule you may need to re-examine your use for
45 correctness given this change.
47 * A new psuedo-target .NOTPARALLEL is available. If defined, the
48 current makefile is run serially regardless of the value of -j.
49 However, submakes are still eligible for parallel execution.
51 * The --debug option has changed: it now allows optional flags
52 controlling the amount and type of debugging output. By default only
53 a minimal amount information is generated, displaying the names of
54 "normal" targets (not makefiles) that were deemed out of date and in
55 need of being rebuilt.
57 Note that the -d option behaves as before: it takes no arguments and
58 all debugging information is generated.
60 * The `-p' (print database) output now includes filename and linenumber
61 information for variable definitions, to aid debugging.
63 * The wordlist function no longer reverses its arguments if the "start"
64 value is greater than the "end" value. If that's true, nothing is
67 * Hartmut Becker provided many updates for the VMS port of GNU make.
68 See the readme.vms file for more details.
72 * Two new functions, $(error ...) and $(warning ...) are available. The
73 former will cause make to fail and exit immediately upon expansion of
74 the function, with the text provided as the error message. The latter
75 causes the text provided to be printed as a warning message, but make
78 * A new function $(call ...) is available. This allows users to create
79 their own parameterized macros and invoke them later. Original
80 implementation of this function was provided by Han-Wen Nienhuys
83 * A new function $(if ...) is available. It provides if-then-else
84 capabilities in a builtin function. Original implementation of this
85 function was provided by Han-Wen Nienhuys <hanwen@cs.uu.nl>.
87 * Make defines a new variable, .LIBPATTERNS. This variable controls how
88 library dependency expansion (dependencies like ``-lfoo'') is performed.
90 * Make accepts CRLF sequences as well as traditional LF, for
91 compatibility with makefiles created on other operating systems.
93 * Make accepts a new option: -R, or --no-builtin-variables. This option
94 disables the definition of the rule-specific builtin variables (CC,
95 LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules)
98 * A "job server" feature, suggested by Howard Chu <hyc@highlandsun.com>.
100 On systems that support POSIX pipe(2) semantics, GNU make can now pass
101 -jN options to submakes rather than forcing them all to use -j1. The
102 top make and all its sub-make processes use a pipe to communicate with
103 each other to ensure that no more than N jobs are started across all
104 makes. To get the old behavior of -j back, you can configure make
105 with the --disable-job-server option.
107 * The confusing term "dependency" has been replaced by the more accurate
108 and standard term "prerequisite", both in the manual and in all GNU make
111 * GNU make supports the "big archive" library format introduced in AIX 4.3.
113 * GNU make supports large files on AIX, HP-UX, and IRIX. These changes
114 were provided by Paul Eggert <eggert@twinsun.com>. (Large file
115 support for Solaris and Linux was introduced in 3.77, but the
116 configuration had issues: these have also been resolved).
118 * The Windows 95/98/NT (W32) version of GNU make now has native support
119 for the Cygnus Cygwin release B20.1 shell (bash).
121 * The GNU make regression test suite, long available separately "under
122 the table", has been integrated into the release. You can invoke it
123 by running "make check" in the distribution. Note that it requires
124 Perl (either Perl 4 or Perl 5) to run.
128 * Implement BSD make's "?=" variable assignment operator. The variable
129 is assigned the specified value only if that variable is not already
132 * Make defines a new variable, "CURDIR", to contain the current working
133 directory (after the -C option, if any, has been processed).
134 Modifying this variable has no effect on the operation of make.
136 * Make defines a new default RCS rule, for new-style master file
137 storage: ``% :: RCS/%'' (note no ``,v'' suffix).
139 Make defines new default rules for DOS-style C++ file naming
140 conventions, with ``.cpp'' suffixes. All the same rules as for
141 ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and
142 COMPILE.cpp macros (which default to the same value as LINK.cc and
143 COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should
144 use CXXFLAGS to change C++ compiler flags.
146 * A new feature, "target-specific variable values", has been added.
147 This is a large change so please see the appropriate sections of the
148 manual for full details. Briefly, syntax like this:
150 TARGET: VARIABLE = VALUE
152 defines VARIABLE as VALUE within the context of TARGET. This is
153 similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note
154 that the assignment may be of any type, not just recursive, and that
155 the override keyword is available.
157 COMPATIBILITY: This new syntax means that if you have any rules where
158 the first or second dependency has an equal sign (=) in its name,
159 you'll have to escape them with a backslash: "foo : bar\=baz".
160 Further, if you have any dependencies which already contain "\=",
161 you'll have to escape both of them: "foo : bar\\\=baz".
163 * A new appendix listing the most common error and warning messages
164 generated by GNU make, with some explanation, has been added to the
165 GNU make User's Manual.
167 * Updates to the GNU make Customs library support (see README.customs).
169 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32),
170 and to the DOS port from Eli Zaretski (see README.DOS).
174 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD.
178 * GNU make now uses automake to control Makefile.in generation. This
179 should make it more consistent with the GNU standards.
181 * VPATH functionality has been changed to incorporate the VPATH+ patch,
182 previously maintained by Paul Smith <psmith@baynetworks.com>. See the
185 * Make defines a new variable, `MAKECMDGOALS', to contain the goals that
186 were specified on the command line, if any. Modifying this variable
187 has no effect on the operation of make.
189 * A new function, `$(wordlist S,E,TEXT)', is available: it returns a
190 list of words from number S to number E (inclusive) of TEXT.
192 * Instead of an error, detection of future modification times gives a
193 warning and continues. The warning is repeated just before GNU make
194 exits, so it is less likely to be lost.
196 * Fix the $(basename) and $(suffix) functions so they only operate on
197 the last filename, not the entire string:
199 Command Old Result New Result
200 ------- ---------- ----------
202 $(basename a.b/c) a a.b/c
204 $(suffix a.b/c) b/c <empty>
206 * The $(strip) function now removes newlines as well as TABs and spaces.
208 * The $(shell) function now changes CRLF (\r\n) pairs to a space as well
211 * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32).
213 * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS
214 and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler
215 and utilities. See README.DOS for details, and direct all questions
216 concerning this port to Eli Zaretskii <eliz@is.elta.co.il> or DJ
217 Delorie <dj@delorie.com>.
219 * John W. Eaton has updated the VMS port to support libraries and VPATH.
223 * The directory messages printed by `-w' and implicitly in sub-makes,
224 are now omitted if Make runs no commands and has no other messages to print.
226 * Make now detects files that for whatever reason have modification times
227 in the future and gives an error. Files with such impossible timestamps
228 can result from unsynchronized clocks, or archived distributions
229 containing bogus timestamps; they confuse Make's dependency engine
232 * The new directive `sinclude' is now recognized as another name for
233 `-include', for compatibility with some other Makes.
235 * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for
236 details, and direct all Amiga-related questions to <digulla@fh-konstanz.de>.
238 * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95.
239 See README.W32 for details, and direct all Windows-related questions to
240 <rob_tulloh@tivoli.com>.
244 * Converted to use Autoconf version 2, so `configure' has some new options.
245 See INSTALL for details.
247 * You can now send a SIGUSR1 signal to Make to toggle printing of debugging
248 output enabled by -d, at any time during the run.
252 * DJ Delorie has ported Make to MS-DOS using the GO32 extender.
253 He is maintaining the DOS port, not the GNU Make maintainer;
254 please direct bugs and questions for DOS to <djgpp@sun.soe.clarkson.edu>.
255 MS-DOS binaries are available for FTP from ftp.simtel.net in
256 /pub/simtelnet/gnu/djgpp/.
258 * The `MAKEFLAGS' variable (in the environment or in a makefile) can now
259 contain variable definitions itself; these are treated just like
260 command-line variable definitions. Make will automatically insert any
261 variable definitions from the environment value of `MAKEFLAGS' or from
262 the command line, into the `MAKEFLAGS' value exported to children. The
263 `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)'
264 for sub-makes is now included in `MAKEFLAGS' instead. As before, you can
265 reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables
266 in the environment when its size is limited.
268 * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of
269 a rule if it has changed when its commands exit with a nonzero status,
270 just as when the commands get a signal.
272 * The automatic variable `$+' is new. It lists all the dependencies like
273 `$^', but preserves duplicates listed in the makefile. This is useful
274 for linking rules, where library files sometimes need to be listed twice
277 * You can now specify the `.IGNORE' and `.SILENT' special targets with
278 dependencies to limit their effects to those files. If a file appears as
279 a dependency of `.IGNORE', then errors will be ignored while running the
280 commands to update that file. Likewise if a file appears as a dependency
281 of `.SILENT', then the commands to update that file will not be printed
282 before they are run. (This change was made to conform to POSIX.2.)
286 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(<D)', `$(?D)', and
287 `$(^D)' now omit the trailing slash from the directory name. (This change
288 was made to comply with POSIX.2.)
290 * The source distribution now includes the Info files for the Make manual.
291 There is no longer a separate distribution containing Info and DVI files.
293 * You can now set the variables `binprefix' and/or `manprefix' in
294 Makefile.in (or on the command line when installing) to install GNU make
295 under a name other than `make' (i.e., ``make binprefix=g install''
296 installs GNU make as `gmake').
298 * The built-in Texinfo rules use the new variables `TEXI2DVI_FLAGS' for
299 flags to the `texi2dvi' script, and `MAKEINFO_FLAGS' for flags to the
302 * The exit status of Make when it runs into errors is now 2 instead of 1.
303 The exit status is 1 only when using -q and some target is not up to date.
304 (This change was made to comply with POSIX.2.)
308 * It is no longer a fatal error to have a NUL character in a makefile.
309 You should never put a NUL in a makefile because it can have strange
310 results, but otherwise empty lines full of NULs (such as produced by
311 the `xmkmf' program) will always work fine.
313 * The error messages for nonexistent included makefiles now refer to the
314 makefile name and line number where the `include' appeared, so Emacs's
315 C-x ` command takes you there (in case it's a typo you need to fix).
319 * Implicit rule search for archive member references is now done in the
320 opposite order from previous versions: the whole target name `LIB(MEM)'
321 first, and just the member name and parentheses `(MEM)' second.
323 * Make now gives an error for an unterminated variable or function reference.
324 For example, `$(foo' with no matching `)' or `${bar' with no matching `}'.
326 * The new default variable `MAKE_VERSION' gives the version number of
327 Make, and a string describing the remote job support compiled in (if any).
328 Thus the value (in this release) is something like `3.69' or `3.69-Customs'.
330 * Commands in an invocation of the `shell' function are no longer run with
331 a modified environment like target commands are. As in versions before
332 3.68, they now run with the environment that `make' started with. We
333 have reversed the change made in version 3.68 because it turned out to
334 cause a paradoxical situation in cases like:
336 export variable = $(shell echo value)
338 When Make attempted to put this variable in the environment for a target
339 command, it would try expand the value by running the shell command
340 `echo value'. In version 3.68, because it constructed an environment
341 for that shell command in the same way, Make would begin to go into an
342 infinite loop and then get a fatal error when it detected the loop.
344 * The commands given for `.DEFAULT' are now used for phony targets with no
349 * You can list several archive member names inside parenthesis:
350 `lib(mem1 mem2 mem3)' is equivalent to `lib(mem1) lib(mem2) lib(mem3)'.
352 * You can use wildcards inside archive member references. For example,
353 `lib(*.o)' expands to all existing members of `lib' whose names end in
354 `.o' (e.g. `lib(a.o) lib(b.o)'); `*.a(*.o)' expands to all such members
355 of all existing files whose names end in `.a' (e.g. `foo.a(a.o)
356 foo.a(b.o) bar.a(c.o) bar.a(d.o)'.
358 * A suffix rule `.X.a' now produces two pattern rules:
359 (%.o): %.X # Previous versions produced only this.
360 %.a: %.X # Now produces this as well, just like other suffixes.
362 * The new flag `--warn-undefined-variables' says to issue a warning message
363 whenever Make expands a reference to an undefined variable.
365 * The new `-include' directive is just like `include' except that there is
366 no error (not even a warning) for a nonexistent makefile.
368 * Commands in an invocation of the `shell' function are now run with a
369 modified environment like target commands are, so you can use `export' et
370 al to set up variables for them. They used to run with the environment
371 that `make' started with.
375 * `make --version' (or `make -v') now exits immediately after printing
380 * Make now supports long-named members in `ar' archive files.
384 * Make now supports the `+=' syntax for a variable definition which appends
385 to the variable's previous value. See the section `Appending More Text
386 to Variables' in the manual for full details.
388 * The new option `--no-print-directory' inhibits the `-w' or
389 `--print-directory' feature. Make turns on `--print-directory'
390 automatically if you use `-C' or `--directory', and in sub-makes; some
391 users have found this behavior undesirable.
393 * The built-in implicit rules now support the alternative extension
394 `.txinfo' for Texinfo files, just like `.texinfo' and `.texi'.
398 * Make now uses a standard GNU `configure' script. See the new file
399 INSTALL for the new (and much simpler) installation procedure.
401 * There is now a shell script to build Make the first time, if you have no
402 other `make' program. `build.sh' is created by `configure'; see README.
404 * GNU Make now completely conforms to the POSIX.2 specification for `make'.
406 * Elements of the `$^' and `$?' automatic variables that are archive
407 member references now list only the member name, as in Unix and POSIX.2.
409 * You should no longer ever need to specify the `-w' switch, which prints
410 the current directory before and after Make runs. The `-C' switch to
411 change directory, and recursive use of Make, now set `-w' automatically.
413 * Multiple double-colon rules for the same target will no longer have their
414 commands run simultaneously under -j, as this could result in the two
415 commands trying to change the file at the same time and interfering with
418 * The `SHELL' variable is now never taken from the environment.
419 Each makefile that wants a shell other than the default (/bin/sh) must
420 set SHELL itself. SHELL is always exported to child processes.
421 This change was made for compatibility with POSIX.2.
423 * Make now accepts long options. There is now an informative usage message
424 that tells you what all the options are and what they do. Try `make --help'.
426 * There are two new directives: `export' and `unexport'. All variables are
427 no longer automatically put into the environments of the commands that
428 Make runs. Instead, only variables specified on the command line or in
429 the environment are exported by default. To export others, use:
431 or you can define variables with:
432 export VARIABLE = VALUE
434 export VARIABLE := VALUE
438 .EXPORT_ALL_VARIABLES:
439 to get the old behavior. See the node `Variables/Recursion' in the manual
440 for a full description.
442 * The commands from the `.DEFAULT' special target are only applied to
443 targets which have no rules at all, not all targets with no commands.
444 This change was made for compatibility with Unix make.
446 * All fatal error messages now contain `***', so they are easy to find in
449 * Dependency file names like `-lNAME' are now replaced with the actual file
450 name found, as with files found by normal directory search (VPATH).
451 The library file `libNAME.a' may now be found in the current directory,
452 which is checked before VPATH; the standard set of directories (/lib,
453 /usr/lib, /usr/local/lib) is now checked last.
454 See the node `Libraries/Search' in the manual for full details.
456 * A single `include' directive can now specify more than one makefile to
459 You can also use shell file name patterns in an `include' directive:
462 * The default directories to search for included makefiles, and for
463 libraries specified with `-lNAME', are now set by configuration.
465 * You can now use blanks as well as colons to separate the directories in a
466 search path for the `vpath' directive or the `VPATH' variable.
468 * You can now use variables and functions in the left hand side of a
469 variable assignment, as in "$(foo)bar = value".
471 * The `MAKE' variable is always defined as `$(MAKE_COMMAND) $(MAKEOVERRIDES)'.
472 The `MAKE_COMMAND' variable is now defined to the name with which make
475 * The built-in rules for C++ compilation now use the variables `$(CXX)' and
476 `$(CXXFLAGS)' instead of `$(C++)' and `$(C++FLAGS)'. The old names had
477 problems with shells that cannot have `+' in environment variable names.
479 * The value of a recursively expanded variable is now expanded when putting
480 it into the environment for child processes. This change was made for
481 compatibility with Unix make.
483 * A rule with no targets before the `:' is now accepted and ignored.
484 This change was made for compatibility with SunOS 4 make.
485 We do not recommend that you write your makefiles to take advantage of this.
487 * The `-I' switch can now be used in MAKEFLAGS, and are put there
488 automatically just like other switches.
492 * Built-in rules for C++ source files with the `.C' suffix.
493 We still recommend that you use `.cc' instead.
495 * If commands are given too many times for a single target,
496 the last set given is used, and a warning message is printed.
498 * Error messages about makefiles are in standard GNU error format,
499 so C-x ` in Emacs works on them.
501 * Dependencies of pattern rules which contain no % need not actually exist
502 if they can be created (just like dependencies which do have a %).
506 * A message is always printed when Make decides there is nothing to be done.
507 It used to be that no message was printed for top-level phony targets
508 (because "`phony' is up to date" isn't quite right). Now a different
509 message "Nothing to be done for `phony'" is printed in that case.
511 * Archives on AIX now supposedly work.
513 * When the commands specified for .DEFAULT are used to update a target,
514 the $< automatic variable is given the same value as $@ for that target.
515 This is how Unix make behaves, and this behavior is mandated by POSIX.2.
519 * The -n, -q, and -t options are not put in the `MAKEFLAGS' and `MFLAG'
520 variables while remaking makefiles, so recursive makes done while remaking
521 makefiles will behave properly.
523 * If the special target `.NOEXPORT' is specified in a makefile,
524 only variables that came from the environment and variables
525 defined on the command line are exported.
529 * Suffix rules may have dependencies (which are ignored).
533 * Dependencies of the form `-lLIB' are searched for as /usr/local/lib/libLIB.a
534 as well as libLIB.a in /usr/lib, /lib, the current directory, and VPATH.
538 * There is now a Unix man page for GNU Make. It is certainly not a replacement
539 for the Texinfo manual, but it documents the basic functionality and the
540 switches. For full documentation, you should still read the Texinfo manual.
541 Thanks to Dennis Morse of Stanford University for contributing the initial
544 * Variables which are defined by default (e.g., `CC') will no longer be put
545 into the environment for child processes. (If these variables are reset by the
546 environment, makefiles, or the command line, they will still go into the
549 * Makefiles which have commands but no dependencies (and thus are always
550 considered out of date and in need of remaking), will not be remade (if they
551 were being remade only because they were makefiles). This means that GNU
552 Make will no longer go into an infinite loop when fed the makefiles that
553 `imake' (necessary to build X Windows) produces.
555 * There is no longer a warning for using the `vpath' directive with an explicit
556 pathname (instead of a `%' pattern).
560 * When removing intermediate files, only one `rm' command line is printed,
561 listing all file names.
563 * There are now automatic variables `$(^D)', `$(^F)', `$(?D)', and `$(?F)'.
564 These are the directory-only and file-only versions of `$^' and `$?'.
566 * Library dependencies given as `-lNAME' will use "libNAME.a" in the current
567 directory if it exists.
569 * The automatic variable `$($/)' is no longer defined.
571 * Leading `+' characters on a command line make that line be executed even
572 under -n, -t, or -q (as if the line contained `$(MAKE)').
574 * For command lines containing `$(MAKE)', `${MAKE}', or leading `+' characters,
575 only those lines are executed, not their entire rules.
576 (This is how Unix make behaves for lines containing `$(MAKE)' or `${MAKE}'.)
580 * Filenames in rules will now have ~ and ~USER expanded.
582 * The `-p' output has been changed so it can be used as a makefile.
583 (All information that isn't specified by makefiles is prefaced with comment
588 * The % character can be quoted with backslash in implicit pattern rules,
589 static pattern rules, `vpath' directives, and `patsubst', `filter', and
590 `filter-out' functions. A warning is issued if a `vpath' directive's
591 pattern contains no %.
593 * The `wildcard' variable expansion function now expands ~ and ~USER.
595 * Messages indicating failed commands now contain the target name:
596 make: *** [target] Error 1
598 * The `-p' output format has been changed somewhat to look more like
599 makefile rules and to give all information that Make has about files.
605 * The `-l' switch with no argument removes any previous load-average limit.
607 * When the `-w' switch is in effect, and Make has updated makefiles,
608 it will write a `Leaving directory' messagfe before re-executing itself.
609 This makes the `directory change tracking' changes to Emacs's compilation
610 commands work properly.
614 * The automatic variable `$*' is now defined for explicit rules,
615 as it is in Unix make.
619 * The `-j' switch is now put in the MAKEFLAGS and MFLAGS variables when
620 specified without an argument (indicating infinite jobs).
621 The `-l' switch is not always put in the MAKEFLAGS and MFLAGS variables.
623 * Make no longer checks hashed directories after running commands.
624 The behavior implemented in 3.41 caused too much slowdown.
628 * A dependency is NOT considered newer than its dependent if
629 they have the same modification time. The behavior implemented
630 in 3.43 conflicts with RCS.
634 * Dependency loops are no longer fatal errors.
636 * A dependency is considered newer than its dependent if
637 they have the same modification time.
641 * The variables F77 and F77FLAGS are now set by default to $(FC) and
642 $(FFLAGS). Makefiles designed for System V make may use these variables in
643 explicit rules and expect them to be set. Unfortunately, there is no way to
644 make setting these affect the Fortran implicit rules unless FC and FFLAGS
645 are not used (and these are used by BSD make).
649 * Make now checks to see if its hashed directories are changed by commands.
650 Other makes that hash directories (Sun, 4.3 BSD) don't do this.
654 * The `shell' function no longer captures standard error output.
658 * A file beginning with a dot can be the default target if it also contains
659 a slash (e.g., `../bin/foo'). (Unix make allows this as well.)
663 * Archive member names are truncated to 15 characters.
665 * Yet more USG stuff.
667 * Minimal support for Microport System V (a 16-bit machine and a
668 brain-damaged compiler). This has even lower priority than other USG
669 support, so if it gets beyond trivial, I will take it out completely.
671 * Revamped default implicit rules (not much visible change).
673 * The -d and -p options can come from the environment.
677 * Improved support for USG and HPUX (hopefully).
679 * A variable reference like `$(foo:a=b)', if `a' contains a `%', is
680 equivalent to `$(patsubst a,b,$(foo))'.
682 * Defining .DEFAULT with no deps or commands clears its commands.
684 * New default implicit rules for .S (cpp, then as), and .sh (copy and make
685 executable). All default implicit rules that use cpp (even indirectly), use
690 * Giving the -j option with no arguments gives you infinite jobs.
694 * New option: "-l LOAD" says not to start any new jobs while others are
695 running if the load average is not below LOAD (a floating-point number).
697 * There is support in place for implementations of remote command execution
698 in Make. See the file remote.c.
702 * No more than 10 directories will be kept open at once.
703 (This number can be changed by redefining MAX_OPEN_DIRECTORIES in dir.c.)
707 * Archive files will have their modification times recorded before doing
708 anything that might change their modification times by updating an archive
713 * The `MAKELEVEL' variable is defined for use by makefiles.
717 * The recursion level indications in error messages are much shorter than
718 they were in version 3.14.
722 * Leading spaces before directives are ignored (as documented).
724 * Included makefiles can determine the default goal target.
725 (System V Make does it this way, so we are being compatible).
729 * Variables that are defaults built into Make will not be put in the
730 environment for children. This just saves some environment space and,
731 except under -e, will be transparent to sub-makes.
733 * Error messages from sub-makes will indicate the level of recursion.
735 * Hopefully some speed-up for large directories due to a change in the
736 directory hashing scheme.
738 * One child will always get a standard input that is usable.
740 * Default makefiles that don't exist will be remade and read in.
744 * Count parentheses inside expansion function calls so you can
745 have nested calls: `$(sort $(foreach x,a b,$(x)))'.
749 * Several bug fixes, including USG and Sun386i support.
751 * `shell' function to expand shell commands a la `
753 * If the `-d' flag is given, version information will be printed.
755 * The `-c' option has been renamed to `-C' for compatibility with tar.
757 * The `-p' option no longer inhibits other normal operation.
759 * Makefiles will be updated and re-read if necessary.
761 * Can now run several commands at once (parallelism), -j option.
763 * Error messages will contain the level of Make recursion, if any.
765 * The `MAKEFLAGS' and `MFLAGS' variables will be scanned for options after
768 * A double-colon rule with no dependencies will always have its commands run.
769 (This is how both the BSD and System V versions of Make do it.)
773 (Changes from versions 1 through 3.05 were never recorded. Sorry.)
775 ----------------------------------------------------------------------
776 Copyright information:
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780 copyright notice and this permission notice are preserved, thus
781 giving the recipient permission to redistribute in turn.
783 Permission is granted to distribute modified versions of this
784 document, or of portions of it, under the above conditions, provided
785 also that they carry prominent notices stating who last changed them.