From 3f1d7622a9a4c818d5d0b20d8a52c09754806d99 Mon Sep 17 00:00:00 2001 From: Stefano Lattarini Date: Wed, 19 Jun 2013 13:22:33 +0200 Subject: NEWS: improve and update wording Signed-off-by: Stefano Lattarini --- NEWS | 150 +++++++++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 87 insertions(+), 63 deletions(-) diff --git a/NEWS b/NEWS index 1cc00a48c..1f74571b1 100644 --- a/NEWS +++ b/NEWS @@ -1,23 +1,24 @@ * WARNING: New versioning scheme for Automake. - - Starting with this version onward, Automake will use an update and - more rational versioning scheme, one that will allow users to know - which kind of changes can be expected from a new version, based on - its version number. - - + Micro versions (e.g., 1.13.3, 2.0.1, 3.2.8) will introduce only - documentation updates and bug and regression fixes; they will - not introduce new features, nor any backward-incompatibility (any + - Beginning with the release 1.13.2, Automake has started to use a + more rational versioning scheme, that should allow users to know + which kind of changes can be expected from a new version, based + on its version number. + + + Micro releases (e.g., 1.13.3, 2.0.1, 3.2.8) introduce only bug + and regression fixes and documentation updates; they should not + introduce new features, nor any backward-incompatibility (any such incompatibility would be considered a bug, to be fixed with a further micro release). - + Minor versions (e.g., 1.14, 2.1) can introduce new backward + + Minor releases (e.g., 1.14, 2.1) can introduce new backward compatible features; the only backward-incompatibilities allowed in such a release are new *non-fatal* deprecations and warnings, and possibly fixes for old or non-trivial bugs (or even inefficient - behaviours) that could unfortunately have been seen, and used, by - some developers as "corner case features". Possible disruptions - caused by this kind of fixes should hopefully be quite rare. + behaviours) that could unfortunately have been seen and used by + some as "corner case features". Possible disruptions caused by + this kind of fixes should hopefully be quite rare, and their + effects limited in scope. + Major versions (now expected to be released every 18 or 24 months, and not more often) can introduce new big features (possibly with @@ -29,26 +30,36 @@ should be duly implemented in the preceding minor releases. - According to this new scheme, the next major version of Automake - (the one that has until now been labelled as '1.14') will actually - become "Automake 2.0". Automake 1.14 will be the next minor version, - which will introduce new features, deprecations and bug fixes, but - no serious backward incompatibility. + (the one that had previously been labelled as "1.14") will actually + become "Automake 2.0". Automake 1.14 is *this* release (which is + a minor one). It introduces new features, deprecations and bug + fixes, but no serious backward incompatibility. A partial exception + is given by the behavioural changes in the AM_PROG_CC_C_O macro + (described in details below) but such changes can also be seen as a + fix for the old suboptimal and somewhat confusing behaviour. - See discussion about automake bug#13578 for more details and background: +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * WARNING: Future backward-incompatibilities! - Makefile recipes generated by Automake 2.0 will expect to use an 'rm' program that doesn't complain when called without any non-option argument if the '-f' option is given (so that commands like "rm -f" and "rm -rf" will act as a no-op, instead of raising usage errors). - Accordingly, AM_INIT_AUTOMAKE will expand new shell code checking - that the default 'rm' program in PATH satisfies this requirement, and - aborting the configure process if this is not the case. This behavior - of 'rm' is very widespread in the wild, and it will be required in the - next POSIX version: - + This behavior of 'rm' is very widespread in the wild, and it will be + required in the next POSIX version: + + + + Accordingly, AM_INIT_AUTOMAKE now expands some shell code that checks + that the default 'rm' program in PATH satisfies this requirement, + aborting the configure process if this is not the case. For the + moment, it's still possible to force the configuration process to + succeed even with a broken 'rm', that that will no longer be the case + for Automake 2.0. - Automake 2.0 will require Autoconf 2.70 or later (which is still unreleased at the moment of writing, but is planned to be released @@ -58,11 +69,12 @@ name for the Autoconf input file. You are advised to start using the recommended name 'configure.ac' instead, ASAP. - - The ACLOCAL_AMFLAGS special make variable will be fully deprecated - in Automake 2.0 (where it will raise warnings in the "obsolete" - category). You are advised to start relying on the new Automake - support for AC_CONFIG_MACRO_DIRS instead (which was introduced in - Automake 1.13). + - The ACLOCAL_AMFLAGS special make variable will be fully deprecated in + Automake 2.0: it will raise warnings in the "obsolete" category (but + still no hard error of course, for compatibilities with the many, many + packages that still relies on that variable). You are advised to + start relying on the new Automake support for AC_CONFIG_MACRO_DIRS + instead (which was introduced in Automake 1.13). - Automake 2.0 will remove support for automatic dependency tracking with the SGI C/C++ compilers on IRIX. The SGI depmode has been @@ -78,7 +90,11 @@ versions will continue to be fully supported. - Automake-provided scripts and makefile recipes might (finally!) - start assuming a POSIX shell in Automake 2.0. + start assuming a POSIX shell in Automake 2.0. There still is no + certainty about this though: we'd first like to wait and see + whether future Autoconf versions will be enhanced to guarantee + that such a shell is always found and provided by the checks in + ./configure. - Starting from Automake 2.0, third-party m4 files located in the system-wide aclocal directory, as well as in any directory listed @@ -95,45 +111,46 @@ New in 1.14: * C compilation, and the AC_PROG_CC and AM_PROG_CC_C_O macros: - - The 'compile' script is now unconditionally required for all - packages that perform C compilation (note that if you are using - the '--add-missing' option, automake will fetch that script for - you, so you shouldn't need any explicit adjustment). - This new behaviour is needed to avoid obscure errors when the - 'subdir-objects' option is used, and the compiler is an inferior - one that doesn't grasp the combined use of both the "-c -o" - options; see discussion about automake bug#13378 for more details: + - The 'compile' script is now unconditionally required for all packages + that perform C compilation (if you are using the '--add-missing' + option, automake will fetch that script for you, so you shouldn't + need any explicit adjustment). This new behaviour is needed to avoid + obscure errors when the 'subdir-objects' option is used, and the + compiler is an inferior one that doesn't grasp the combined use of + both the "-c -o" options; see discussion about automake bug#13378 for + more details: - - The next major Automake version (2.0) will unconditionally turn on + - The next major Automake version (2.0) will unconditionally activate the 'subdir-objects' option. In order to smooth out the transition, we now give a warning (in the category 'unsupported') whenever a source file is present in a subdirectory but the 'subdir-object' is not enabled. For example, the following usage will trigger such a - warning (of course, assuming the 'subdir-objects' option is off): + warning: bin_PROGRAMS = sub/foo sub_foo_SOURCES = sub/main.c sub/bar.c - - Automake will automatically enhance the AC_PROG_CC autoconf macro - to make it check, at configure time, that the C compiler supports - the combined use of both the "-c -o" options. The result of this - check is saved in the cache variable 'am_cv_prog_cc_c_o', and said - result can be overridden by pre-defining that variable. + - Automake will automatically enhance the autoconf-provided macro + AC_PROG_CC to force it to check, at configure time, that the + C compiler supports the combined use of both the '-c' and '-o' + options. The result of this check is saved in the cache variable + 'am_cv_prog_cc_c_o', and said result can be overridden by + pre-defining that variable. - - The AM_PROG_CC_C_O can still be called, but that should no longer - be necessary. This macro is now just a thin wrapper around the + - The AM_PROG_CC_C_O macro can still be called, albeit that should no + longer be necessary. This macro is now just a thin wrapper around the Automake-enhanced AC_PROG_CC. This means, among the other things, that its behaviour is changed in three ways: 1. It no longer invokes the Autoconf-provided AC_PROG_CC_C_O - macros behind the scenes. + macro behind the scenes. - 2. It caches the check result in the 'am_cv_prog_cc_c_o'variable, + 2. It caches the check result in the 'am_cv_prog_cc_c_o' variable, and not in a 'ac_cv_prog_cc_*_c_o' variable whose exact name - in only dynamically computed at configure runtime (sic!) from - the content of the '$CC' variable. + in only dynamically computed *at configure runtime* from the + content of the '$CC' variable. 3. It no longer automatically AC_DEFINE the C preprocessor symbol 'NO_MINUS_C_MINUS_O'. @@ -149,10 +166,10 @@ New in 1.14: - For quite a long time, Automake has been implementing an undocumented hack which ensured that '.info' files which appeared to be cleaned - (by e.g. being listed in the CLEANFILES or DISTCLEANFILES variables) - were built in the builddir rather than in the srcdir; this hack was - introduced to ensure better backward-compatibility with packages such - as Texinfo, which did things like: + (by being listed in the CLEANFILES or DISTCLEANFILES variables) were + built in the builddir rather than in the srcdir; this hack was + introduced to ensure better backward-compatibility with package + such as Texinfo, which do things like: info_TEXINFOS = texinfo.txi info-stnd.texi info.texi DISTCLEANFILES = texinfo texinfo-* info*.info* @@ -172,19 +189,27 @@ New in 1.14: - The special Automake-time substitutions '%reldir%' and '%canon_reldir%' (and their short versions, '%D%' and '%C%' respectively) can now be used in an included Makefile fragment. The former is substituted with the - relative directory of the included fragment (compared to the top level + relative directory of the included fragment (compared to the top-level including Makefile), and the latter with the canonicalized version of - the same relative directory: + the same relative directory. + + # in 'Makefile.am': + bin_PROGRAMS = # will be updated by included Makefile fragments + include src/Makefile.inc + # in 'src/Makefile.inc': bin_PROGRAMS += %reldir%/foo %canon_reldir%_foo_SOURCES = %reldir%/bar.c + This should be especially useful for packages using a non-recursive + build system. + * Deprecated distribution formats: - The 'shar' and 'compress' distribution formats are deprecated, and scheduled for removal in Automake 2.0. Accordingly, the use of the 'dist-shar' and 'dist-tarZ' will cause warnings at automake runtime - (in the 'obsolete' category), and the recipes for the Automake-generated + (in the 'obsolete' category), and the recipes of the Automake-generated targets 'dist-shar' and 'dist-tarZ' will unconditionally display (non-fatal) warnings at make runtime. @@ -193,13 +218,12 @@ New in 1.14: - To simplify transition to Automake 2.0, the shell code expanded by AM_INIT_AUTOMAKE now checks (at configure runtime) that the default 'rm' program in PATH doesn't complain when called without any - non-option argument if the '-f' option is given (so that commands - like "rm -f" and "rm -rf" act as a no-op, instead of raising usage - error). If this is not the case, - the configure script is aborted, to call the attention of the user - on the issue, and invite him to fix his PATH. The checked 'rm' - behavior is very widespread in the wild, and will be required by - future POSIX version: + non-option argument if the '-f' option is given (so that commands like + "rm -f" and "rm -rf" act as a no-op, instead of raising usage errors). + If this is not the case, the configure script is aborted, to call the + attention of the user on the issue, and invite him to fix his PATH. + The checked 'rm' behavior is very widespread in the wild, and will be + required by future POSIX versions: -- cgit v1.2.1