GNU make NEWS -*-indented-text-*- History of user-visible changes. 25 Oct 2009 See the end of this file for copyrights and conditions. All changes mentioned here are more fully described in the GNU make manual, which is contained in this distribution as the file doc/make.texi. See the README file and the GNU make manual for instructions for reporting bugs. Version 3.81.90 * Compiling GNU make now requires a conforming ISO C 1989 compiler and standard runtime library. * WARNING: Backward-incompatibility! The POSIX standard for make was changed in the 2008 version in a fundamentally incompatible way: make is required to invoke the shell as if the '-e' flag were provided. Because this would break many makefiles that have been written to conform to the original text of the standard, the default behavior of GNU make remains to invoke the shell with simply '-c'. However, any makefile specifying the .POSIX special target will follow the new POSIX standard and pass '-e' to the shell. See also .SHELLFLAGS below. * WARNING: Backward-incompatibility! The '$?' variable now contains all prerequisites that caused the target to be considered out of date, even if they do not exist (previously only existing targets were provided in $?). * WARNING: Backward-incompatibility! As a result of parser enhancements, three backward-compatibility issues exist: first, a prerequisite containing an "=" cannot be escaped with a backslash any longer. You must create a variable containing an "=" and use that variable in the prerequisite. Second, variable names can no longer contain whitespace, unless you put the whitespace in a variable and use the variable. Third, in previous versions of make it was sometimes not flagged as an error for explicit and pattern targets to appear in the same rule. Now this is always reported as an error. * WARNING: Backward-incompatibility! The pattern-specific variables and pattern rules are now applied in the shortest stem first order instead of the definition order (variables and rules with the same stem length are still applied in the definition order). This produces the usually-desired behavior where more specific patterns are preferred. To detect this feature search for 'shortest-stem' in the .FEATURES special variable. * WARNING: Backward-incompatibility! The library search behavior has changed to be compatible with the standard linker behavior. Prior to this version for prerequisites specified using the -lfoo syntax make fist searched for libfoo.so in the current directory, vpath directories, and system directories. If that didn't yield a match, make then searched for libfoo.a in these directories. Starting with this version make searches first for libfoo.so and then for libfoo.a in each of these directories in order. * New command line option: --eval=STRING causes STRING to be evaluated as makefile syntax (akin to using the $(eval ...) function). The evaluation is performed after all default rules and variables are defined, but before any makefiles are read. * New special variable: .RECIPEPREFIX allows you to reset the recipe introduction character from the default (TAB) to something else. The first character of this variable value is the new recipe introduction character. If the variable is set to the empty string, TAB is used again. It can be set and reset at will; recipes will use the value active when they were first parsed. To detect this feature check the value of $(.RECIPEPREFIX). * New special variable: .SHELLFLAGS allows you to change the options passed to the shell when it invokes recipes. By default the value will be "-c" (or "-ec" if .POSIX is set). * New special target: .ONESHELL instructs make to invoke a single instance of the shell and provide it with the entire recipe, regardless of how many lines it contains. As a special feature to allow more straightforward conversion of makefiles to use .ONESHELL, any recipe line control characters ('@', '+', or '-') will be removed from the second and subsequent recipe lines. This happens _only_ if the SHELL value is deemed to be a standard POSIX-style shell. If not, then no interior line control characters are removed (as they may be part of the scripting language used with the alternate SHELL). * New variable modifier 'private': prefixing a variable assignment with the modifier 'private' suppresses inheritance of that variable by prerequisites. This is most useful for target- and pattern-specific variables. * New make directive: 'undefine' allows you to undefine a variable so that it appears as if it was never set. Both $(flavor) and $(origin) functions will return 'undefined' for such a variable. To detect this feature search for 'undefine' in the .FEATURES special variable. * The parser for variable assignments has been enhanced to allow multiple modifiers ('export', 'override', 'private') on the same line as variables, including define/endef variables, and in any order. Also, it is possible to create variables and targets named as these modifiers. * The 'define' make directive now allows a variable assignment operator after the variable name, to allow for simple, conditional, or appending multi-line variable assignment. Version 3.81 * GNU make is ported to OS/2. * GNU make is ported to MinGW. The MinGW build is only supported by the build_w32.bat batch file; see the file README.W32 for more details. * WARNING: Future backward-incompatibility! Up to and including this release, the '$?' variable does not contain any prerequisite that does not exist, even though that prerequisite might have caused the target to rebuild. Starting with the _next_ release of GNU make, '$?' will contain all prerequisites that caused the target to be considered out of date. See this Savannah bug: http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=16051 * WARNING: Backward-incompatibility! GNU make now implements a generic "second expansion" feature on the prerequisites of both explicit and implicit (pattern) rules. In order to enable this feature, the special target '.SECONDEXPANSION' must be defined before the first target which takes advantage of it. If this feature is enabled then after all rules have been parsed the prerequisites are expanded again, this time with all the automatic variables in scope. This means that in addition to using standard SysV $$@ in prerequisites lists, you can also use complex functions such as $$(notdir $$@) etc. This behavior applies to implicit rules, as well, where the second expansion occurs when the rule is matched. However, this means that when '.SECONDEXPANSION' is enabled you must double-quote any "$" in your filenames; instead of "foo: boo$$bar" you now must write "foo: foo$$$$bar". Note that the SysV $$@ etc. feature, which used to be available by default, is now ONLY available when the .SECONDEXPANSION target is defined. If your makefiles take advantage of this SysV feature you will need to update them. * WARNING: Backward-incompatibility! In order to comply with POSIX, the way in which GNU make processes backslash-newline sequences in recipes has changed. If your makefiles use backslash-newline sequences inside of single-quoted strings in recipes you will be impacted by this change. See the GNU make manual subsection "Splitting Recipe Lines" (node "Splitting Lines"), in section "Recipe Syntax", chapter "Writing Recipe in Rules", for details. * WARNING: Backward-incompatibility! Some previous versions of GNU make had a bug where "#" in a function invocation such as $(shell ...) was treated as a make comment. A workaround was to escape these with backslashes. This bug has been fixed: if your makefile uses "\#" in a function invocation the backslash is now preserved, so you'll need to remove it. * New command line option: -L (--check-symlink-times). On systems that support symbolic links, if this option is given then GNU make will use the most recent modification time of any symbolic links that are used to resolve target files. The default behavior remains as it always has: use the modification time of the actual target file only. * The "else" conditional line can now be followed by any other valid conditional on the same line: this does not increase the depth of the conditional nesting, so only one "endif" is required to close the conditional. * All pattern-specific variables that match a given target are now used (previously only the first match was used). * Target-specific variables can be marked as exportable using the "export" keyword. * In a recursive $(call ...) context, any extra arguments from the outer call are now masked in the context of the inner call. * Implemented a solution for the "thundering herd" problem with "-j -l". This version of GNU make uses an algorithm suggested by Thomas Riedl to track the number of jobs started in the last second and artificially adjust GNU make's view of the system's load average accordingly. * New special variables available in this release: - .INCLUDE_DIRS: Expands to a list of directories that make searches for included makefiles. - .FEATURES: Contains a list of special features available in this version of GNU make. - .DEFAULT_GOAL: Set the name of the default goal make will use if no goals are provided on the command line. - MAKE_RESTARTS: If set, then this is the number of times this instance of make has been restarted (see "How Makefiles Are Remade" in the manual). - New automatic variable: $| (added in 3.80, actually): contains all the order-only prerequisites defined for the target. * New functions available in this release: - $(lastword ...) returns the last word in the list. This gives identical results as $(word $(words ...) ...), but is much faster. - $(abspath ...) returns the absolute path (all "." and ".." directories resolved, and any duplicate "/" characters removed) for each path provided. - $(realpath ...) returns the canonical pathname for each path provided. The canonical pathname is the absolute pathname, with all symbolic links resolved as well. - $(info ...) prints its arguments to stdout. No makefile name or line number info, etc. is printed. - $(flavor ...) returns the flavor of a variable. - $(or ...) provides a short-circuiting OR conditional: each argument is expanded. The first true (non-empty) argument is returned; no further arguments are expanded. Expands to empty if there are no true arguments. - $(and ...) provides a short-circuiting AND conditional: each argument is expanded. The first false (empty) argument is returned; no further arguments are expanded. Expands to the last argument if all arguments are true. * Changes made for POSIX compatibility: - Only touch targets (under -t) if they have a recipe. - Setting the SHELL make variable does NOT change the value of the SHELL environment variable given to programs invoked by make. As an enhancement to POSIX, if you export the make variable SHELL then it will be set in the environment, just as before. * On MS Windows systems, explicitly setting SHELL to a pathname ending in "cmd" or "cmd.exe" (case-insensitive) will force GNU make to use the DOS command interpreter in batch mode even if a UNIX-like shell could be found on the system. * On VMS there is now support for case-sensitive filesystems such as ODS5. See the readme.vms file for information. * Parallel builds (-jN) no longer require a working Bourne shell on Windows platforms. They work even with the stock Windows shells, such as cmd.exe and command.com. * Updated to autoconf 2.59, automake 1.9.5, and gettext 0.14.1. Users should not be impacted. * New translations for Swedish, Chinese (simplified), Ukrainian, Belarusian, Finnish, Kinyarwandan, and Irish. Many updated translations. A complete list of bugs fixed in this version is available here: http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=103 Version 3.80 * A new feature exists: order-only prerequisites. These prerequisites affect the order in which targets are built, but they do not impact the rebuild/no-rebuild decision of their dependents. That is to say, they allow you to require target B be built before target A, without requiring that target A will always be rebuilt if target B is updated. Patch for this feature provided by Greg McGary . * For compatibility with SysV make, GNU make now supports the peculiar syntax $$@, $$(@D), and $$(@F) in the prerequisites list of a rule. This syntax is only valid within explicit and static pattern rules: it cannot be used in implicit (suffix or pattern) rules. Edouard G. Parmelan provided a patch implementing this feature; however, I decided to implement it in a different way. * The argument to the "ifdef" conditional is now expanded before it's tested, so it can be a constructed variable name. Similarly, the arguments to "export" (when not used in a variable definition context) and "unexport" are also now expanded. * A new function is defined: $(value ...). The argument to this function is the _name_ of a variable. The result of the function is the value of the variable, without having been expanded. * A new function is defined: $(eval ...). The arguments to this function should expand to makefile commands, which will then be evaluated as if they had appeared in the makefile. In combination with define/endef multiline variable definitions this is an extremely powerful capability. The $(value ...) function is also sometimes useful here. * A new built-in variable is defined, $(MAKEFILE_LIST). It contains a list of each makefile GNU make has read, or started to read, in the order in which they were encountered. So, the last filename in the list when a makefile is just being read (before any includes) is the name of the current makefile. * A new built-in variable is defined: $(.VARIABLES). When it is expanded it returns a complete list of variable names defined by all makefiles at that moment. * A new command line option is defined, -B or --always-make. If specified GNU make will consider all targets out-of-date even if they would otherwise not be. * The arguments to $(call ...) functions were being stored in $1, $2, etc. as recursive variables, even though they are fully expanded before assignment. This means that escaped dollar signs ($$ etc.) were not behaving properly. Now the arguments are stored as simple variables. This may mean that if you added extra escaping to your $(call ...) function arguments you will need to undo it now. * The variable invoked by $(call ...) can now be recursive: unlike other variables it can reference itself and this will not produce an error when it is used as the first argument to $(call ...) (but only then). * New pseudo-target .LOW_RESOLUTION_TIME, superseding the configure option --disable-nsec-timestamps. You might need this if your build process depends on tools like "cp -p" preserving time stamps, since "cp -p" (right now) doesn't preserve the subsecond portion of a time stamp. * Updated translations for French, Galician, German, Japanese, Korean, and Russian. New translations for Croatian, Danish, Hebrew, and Turkish. * Updated internationalization support to Gettext 0.11.5. GNU make now uses Gettext's "external" feature, and does not include any internationalization code itself. Configure will search your system for an existing implementation of GNU Gettext (only GNU Gettext is acceptable) and use it if it exists. If not, NLS will be disabled. See ABOUT-NLS for more information. * Updated to autoconf 2.54 and automake 1.7. Users should not be impacted. A complete list of bugs fixed in this version is available here: http://savannah.gnu.org/bugs/index.php?group=make&report_id=111&fix_release_id=102 Version 3.79.1 * .SECONDARY with no prerequisites now prevents any target from being removed because make thinks it's an intermediate file, not just those listed in the makefile. * New configure option --disable-nsec-timestamps, but this was superseded in later versions by the .LOW_RESOLUTION_TIME pseudo-target. Version 3.79 * GNU make optionally supports internationalization and locales via the GNU gettext (or local gettext if suitable) package. See the ABOUT-NLS file for more information on configuring GNU make for NLS. * Previously, GNU make quoted variables such as MAKEFLAGS and MAKEOVERRIDES for proper parsing by the shell. This allowed them to be used within make build scripts. However, using them there is not proper behavior: they are meant to be passed to subshells via the environment. Unfortunately the values were not quoted properly to be passed through the environment. This meant that make didn't properly pass some types of command line values to submakes. With this version we change that behavior: now these variables are quoted properly for passing through the environment, which is the correct way to do it. If you previously used these variables explicitly within a make rule you may need to re-examine your use for correctness given this change. * A new pseudo-target .NOTPARALLEL is available. If defined, the current makefile is run serially regardless of the value of -j. However, submakes are still eligible for parallel execution. * The --debug option has changed: it now allows optional flags controlling the amount and type of debugging output. By default only a minimal amount information is generated, displaying the names of "normal" targets (not makefiles) that were deemed out of date and in need of being rebuilt. Note that the -d option behaves as before: it takes no arguments and all debugging information is generated. * The `-p' (print database) output now includes filename and linenumber information for variable definitions, to aid debugging. * The wordlist function no longer reverses its arguments if the "start" value is greater than the "end" value. If that's true, nothing is returned. * Hartmut Becker provided many updates for the VMS port of GNU make. See the readme.vms file for more details. Version 3.78 * Two new functions, $(error ...) and $(warning ...) are available. The former will cause make to fail and exit immediately upon expansion of the function, with the text provided as the error message. The latter causes the text provided to be printed as a warning message, but make proceeds normally. * A new function $(call ...) is available. This allows users to create their own parameterized macros and invoke them later. Original implementation of this function was provided by Han-Wen Nienhuys . * A new function $(if ...) is available. It provides if-then-else capabilities in a builtin function. Original implementation of this function was provided by Han-Wen Nienhuys . * Make defines a new variable, .LIBPATTERNS. This variable controls how library dependency expansion (dependencies like ``-lfoo'') is performed. * Make accepts CRLF sequences as well as traditional LF, for compatibility with makefiles created on other operating systems. * Make accepts a new option: -R, or --no-builtin-variables. This option disables the definition of the rule-specific builtin variables (CC, LD, AR, etc.). Specifying this option forces -r (--no-builtin-rules) as well. * A "job server" feature, suggested by Howard Chu . On systems that support POSIX pipe(2) semantics, GNU make can now pass -jN options to submakes rather than forcing them all to use -j1. The top make and all its sub-make processes use a pipe to communicate with each other to ensure that no more than N jobs are started across all makes. To get the old behavior of -j back, you can configure make with the --disable-job-server option. * The confusing term "dependency" has been replaced by the more accurate and standard term "prerequisite", both in the manual and in all GNU make output. * GNU make supports the "big archive" library format introduced in AIX 4.3. * GNU make supports large files on AIX, HP-UX, and IRIX. These changes were provided by Paul Eggert . (Large file support for Solaris and Linux was introduced in 3.77, but the configuration had issues: these have also been resolved). * The Windows 95/98/NT (W32) version of GNU make now has native support for the Cygnus Cygwin release B20.1 shell (bash). * The GNU make regression test suite, long available separately "under the table", has been integrated into the release. You can invoke it by running "make check" in the distribution. Note that it requires Perl (either Perl 4 or Perl 5) to run. Version 3.77 * Implement BSD make's "?=" variable assignment operator. The variable is assigned the specified value only if that variable is not already defined. * Make defines a new variable, "CURDIR", to contain the current working directory (after the -C option, if any, has been processed). Modifying this variable has no effect on the operation of make. * Make defines a new default RCS rule, for new-style master file storage: ``% :: RCS/%'' (note no ``,v'' suffix). Make defines new default rules for DOS-style C++ file naming conventions, with ``.cpp'' suffixes. All the same rules as for ``.cc'' and ``.C'' suffixes are provided, along with LINK.cpp and COMPILE.cpp macros (which default to the same value as LINK.cc and COMPILE.cc). Note CPPFLAGS is still C preprocessor flags! You should use CXXFLAGS to change C++ compiler flags. * A new feature, "target-specific variable values", has been added. This is a large change so please see the appropriate sections of the manual for full details. Briefly, syntax like this: TARGET: VARIABLE = VALUE defines VARIABLE as VALUE within the context of TARGET. This is similar to SunOS make's "TARGET := VARIABLE = VALUE" feature. Note that the assignment may be of any type, not just recursive, and that the override keyword is available. COMPATIBILITY: This new syntax means that if you have any rules where the first or second dependency has an equal sign (=) in its name, you'll have to escape them with a backslash: "foo : bar\=baz". Further, if you have any dependencies which already contain "\=", you'll have to escape both of them: "foo : bar\\\=baz". * A new appendix listing the most common error and warning messages generated by GNU make, with some explanation, has been added to the GNU make User's Manual. * Updates to the GNU make Customs library support (see README.customs). * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32), and to the DOS port from Eli Zaretski (see README.DOS). Version 3.76.1 * Small (but serious) bug fix. Quick rollout to get into the GNU source CD. Version 3.76 * GNU make now uses automake to control Makefile.in generation. This should make it more consistent with the GNU standards. * VPATH functionality has been changed to incorporate the VPATH+ patch, previously maintained by Paul Smith . See the manual. * Make defines a new variable, `MAKECMDGOALS', to contain the goals that were specified on the command line, if any. Modifying this variable has no effect on the operation of make. * A new function, `$(wordlist S,E,TEXT)', is available: it returns a list of words from number S to number E (inclusive) of TEXT. * Instead of an error, detection of future modification times gives a warning and continues. The warning is repeated just before GNU make exits, so it is less likely to be lost. * Fix the $(basename) and $(suffix) functions so they only operate on the last filename, not the entire string: Command Old Result New Result ------- ---------- ---------- $(basename a.b) a a $(basename a.b/c) a a.b/c $(suffix a.b) b b $(suffix a.b/c) b/c * The $(strip) function now removes newlines as well as TABs and spaces. * The $(shell) function now changes CRLF (\r\n) pairs to a space as well as newlines (\n). * Updates to the Windows 95/NT port from Rob Tulloh (see README.W32). * Eli Zaretskii has updated the port to 32-bit protected mode on MSDOS and MS-Windows, building with the DJGPP v2 port of GNU C/C++ compiler and utilities. See README.DOS for details, and direct all questions concerning this port to Eli Zaretskii or DJ Delorie . * John W. Eaton has updated the VMS port to support libraries and VPATH. Version 3.75 * The directory messages printed by `-w' and implicitly in sub-makes, are now omitted if Make runs no commands and has no other messages to print. * Make now detects files that for whatever reason have modification times in the future and gives an error. Files with such impossible timestamps can result from unsynchronized clocks, or archived distributions containing bogus timestamps; they confuse Make's dependency engine thoroughly. * The new directive `sinclude' is now recognized as another name for `-include', for compatibility with some other Makes. * Aaron Digulla has contributed a port to AmigaDOS. See README.Amiga for details, and direct all Amiga-related questions to . * Rob Tulloh of Tivoli Systems has contributed a port to Windows NT or 95. See README.W32 for details, and direct all Windows-related questions to . Version 3.73 * Converted to use Autoconf version 2, so `configure' has some new options. See INSTALL for details. * You can now send a SIGUSR1 signal to Make to toggle printing of debugging output enabled by -d, at any time during the run. Version 3.72 * DJ Delorie has ported Make to MS-DOS using the GO32 extender. He is maintaining the DOS port, not the GNU Make maintainer; please direct bugs and questions for DOS to . MS-DOS binaries are available for FTP from ftp.simtel.net in /pub/simtelnet/gnu/djgpp/. * The `MAKEFLAGS' variable (in the environment or in a makefile) can now contain variable definitions itself; these are treated just like command line variable definitions. Make will automatically insert any variable definitions from the environment value of `MAKEFLAGS' or from the command line, into the `MAKEFLAGS' value exported to children. The `MAKEOVERRIDES' variable previously included in the value of `$(MAKE)' for sub-makes is now included in `MAKEFLAGS' instead. As before, you can reset `MAKEOVERRIDES' in your makefile to avoid putting all the variables in the environment when its size is limited. * If `.DELETE_ON_ERROR' appears as a target, Make will delete the target of a rule if it has changed when its recipe exits with a nonzero status, just as when the recipe gets a signal. * The automatic variable `$+' is new. It lists all the dependencies like `$^', but preserves duplicates listed in the makefile. This is useful for linking rules, where library files sometimes need to be listed twice in the link order. * You can now specify the `.IGNORE' and `.SILENT' special targets with dependencies to limit their effects to those files. If a file appears as a dependency of `.IGNORE', then errors will be ignored while running the recipe to update that file. Likewise if a file appears as a dependency of `.SILENT', then the recipe to update that file will not be printed before it is run. (This change was made to conform to POSIX.2.) Version 3.71 * The automatic variables `$(@D)', `$(%D)', `$(*D)', `$(.