There are two errors caught by make syntax-check currently.
First, the recent make update-copyright
(d78a7dd95f) missed autoconf.texi, I
think because there are a bunch of .texi files in doc/ whose copyright
years should *not* be updated (e.g. standards.texi, fdl.texi) and the
exclusion pattern is too broad. I can't actually *find* the exclusion
pattern in the twisty maze of .mk files, all alike, so I just manually
updated autoconf.texi.
Second, it objects to an edit to an old section of NEWS. This is
because of d3dcd5895d, which is a
legitimate change (replacing http:// with https:// in a URL) so the
correct action is to change old_NEWS_hash to match.
* doc/autoconf.texi: Update copyright year.
* cfg.mk (old_NEWS_hash): Update to acknowledge commit
d3dcd5895d.
* doc/autoconf.texi (C and Posix Variants, System Services):
Remind user to include config.h first.
(Configuration Headers): Give another reason why config.h must be
first, and mention that only .c files need it.
Based on discussion on bugs.debian.org/158969
Signed-off-by: Eric Blake <eblake@redhat.com>
Several projects have a bootstrap script that invokes
'autoreconf -fi' as part of a fresh version control checkout,
in order to avoid storing common files in version control,
while also allowing contributors to rerun bootstrap to pick
up the benefits of any upgrade of one of the autotools.
However, the documentation did not make it obvious that such
a setup will overwrite any customizations to files like
INSTALL, if those files are stored in version control, when
automake still considers that file to be standard based on
AM_INIT_AUTOMAKE settings. In such a case, a mere
'autoreconf -i' is good for the bootstrap script, while a
separate 'autoreconf -f' is good for picking up on an upgrade
of any autotools.
* bin/autoreconf.in (help): Mention standard files.
* doc/autoconf.texi (autoreconf Invocation): Add more text, including
warning that mixing --force and --install may undo customizations,
and that the set of files impacted is controlled by automake.
Reported by Emil Laine <laine.emil@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The example text regarding a desired literal AC_DC in output
claimed that the result would trigger a warning if one does
not use creative quoting; but in reality, autoconf's use of
m4_pattern_forbid to reserve the entire AC_ namespace makes
it a hard error. Reword the section to mention the use of
m4_pattern_allow() as the fix, and beef up the example to
better demonstrate the problem.
* doc/autoconf.texi (Autoconf Language): Improve AC_DC example.
Reported by Gavin Smith <gavinsmith0123@gmail.com>.
Signed-off-by: Eric Blake <eblake@redhat.com>
The "single" macro infinitely recurses because its expansion contains
the unquoted text " single-". The "double" macro almost has the same
problem, but it is protected by extra quotes. In any case, the macro
names being repeated in the macro definitions is not necessary.
This commit changes the macro names to "foo" and "bar", which are taken
from a very similar example in the GNU M4 1.4.17 manual. See lines 1971
to 1980 of v1.4.17:doc/m4.texi in the GNU M4 Git repository.
* doc/autoconf.texi (Quoting and Parameters): Fix broken example.
* doc/autoconf.texi (C and Posix Variants): Rename from "Posix
Variants", and document updated behavior.
* lib/autoconf/specific.m4 (AC_USE_SYSTEM_EXTENSIONS): Also define
__STDC_WANT_IEC_60559_ATTRIBS_EXT__,
__STDC_WANT_IEC_60559_DFP_EXT__,
__STDC_WANT_IEC_60559_TYPES_EXT__, and
__STDC_WANT_MATH_SPEC_FUNCS__. From a suggestion by Joseph Myers in:
http://lists.gnu.org/archive/html/autoconf-patches/2016-09/msg00011.html
glibc 2.25 is deprecating the namespace pollution of <sys/types.h>
injecting major(), minor(), and makedev() into the compilation
environment, with a warning that insists that users include
<sys/sysmacros.h> instead. However, because the expansion of
AC_HEADER_MAJOR didn't bother checking sys/sysmacros.h until
after probing whether sys/types.h pollutes the namespace, it was
not defining MAJOR_IN_SYSMACROS, with the result that code
compiled with -Werror chokes on the deprecation warnings because
it was not including sysmacros.h.
In addition to fixing autoconf (which only benefits projects
that rebuild configure after this fix is released), we can also
give a hint to distros on how they can populate config.site with
a cache variable to force pre-existing configure scripts without
the updated macro to behave sanely in the presence of glibc 2.25
(the documentation is especially useful since that cache variable
is no longer present in autoconf after this patch).
Note that mingw lacks major/minor/makedev in any of its standard
headers; for that platform, the behavior of this macro is unchanged
(code using the recommended include formula will get a compile error
when trying to use major(), whether before or after this patch); but
for now, it is assumed that programs actually concerned with
creating devices are not worried about portability to mingw. If
desired, a later patch could tighten AC_HEADER_MAJOR to fail at
configure time if the macros are unavailable in any of the three
system headers, but that semantic change is not worth mixing into
this patch.
* lib/autoconf/headers.m4 (AC_HEADER_MAJOR): Drop check for
major within sys/types.h; it interferes with the need to check
sysmacros.h first.
* doc/autoconf.texi (Particular Headers) <AC_HEADER_MAJOR>: Expand
details on usage, and on workarounds for non-updated projects.
Signed-off-by: Eric Blake <eblake@redhat.com>
* lib/autoconf/specific.m4 (AC_USE_SYSTEM_EXTENSIONS):
Also define __STDC_WANT_IEC_60559_BFP_EXT__,
__STDC_WANT_IEC_60559_FUNCS_EXT__, and __STDC_WANT_LIB_EXT2__.
* NEWS, doc/autoconf.texi (Posix Variants):
Document this. Also, document other changes in this area
that were not properly documented before.
Silences this warning from new-enough texinfo:
./doc/autoconf.texi:14236: warning: @xref node name should not contain `.'
* doc/autoconf.texi (Macro Definitions): No need for .info.
Signed-off-by: Eric Blake <eblake@redhat.com>
Based on a report by Michael Felt, via Paul Eggert on the
coreutils list.
* doc/autoconf.texi (Limitations of Builtins) <for>: Document
problem with 'for var in ;'.
Signed-off-by: Eric Blake <eblake@redhat.com>
* lib/autoconf/general.m4 (_AC_UNDECLARED_WARNING): New macro.
(_AC_CHECK_DECL_BODY): Call it once per language; treat warnings as
errors when its verdict indicates that.
* tests/semantics.at (AC_CHECK_DECLS): Add a macro call that relies on
the new semantics. Avoid -Wmissing-variable-declarations warnings.
* doc/autoconf.texi (Generic Declarations): Document the implications.
* NEWS: Mention this change.
Give a more concrete description of what the m4_pattern_forbid
thingy that pretends it is a macro accepts as an argument.
Copyright-paper-exempt: Yes
Signed-off-by: Eric Blake <eblake@redhat.com>
Based on an idea by Bernhard Reutner-Fischer.
We frequently used the idiom of 'test "${var+set}" = set' to
test if $var was set to a non-empty string, but this can portably
be trimmed to a more compact 'test ${var+y}' for a smaller
configure file. Testing that a variable is not set can be done
with '${var+false} :' (although the value of $? is not reliably
1 when the variable is set).
The code for AS_VAR_TEST_SET already used the form '${var+:} false',
but it is slightly longer, and does not guarantee $? of 1.
Tested on coreutils, where the resulting configure file is about
1k smaller.
* doc/autoconf.texi (Shell Substitutions): Prefer shorter sequence
for testing if a variable is set.
(Limitations of Builtins) <test (strings)>: Document it.
* configure.ac: Use it.
* lib/autoconf/c.m4 (_AC_PROG_CC_G, _AC_PROG_CXX_G)
(_AC_PROG_OBJC_G, _AC_PROG_OBJCXX_G): Likewise.
* lib/autoconf/fortran.m4 (_AC_PROG_FC_G): Likewise.
* lib/autoconf/general.m4 (_AC_ENABLE_IF_ACTION, AC_CACHE_SAVE):
Likewise.
* lib/autoconf/lang.m4 (_AC_COMPILER_EXEEXT_DEFAULT): Likewise.
* lib/autoconf/programs.m4 (AC_PROG_INSTALL, AC_PROG_MKDIR_P)
(_AC_PROG_LEX_YYTEXT_DECL): Likewise.
* lib/autoconf/status.m4 (_AC_OUTPUT_MAIN_LOOP): Likewise.
* lib/autotest/general.m4 (AT_INIT): Likewise.
* tests/base.at (AC_CACHE_CHECK): Likewise.
* tests/m4sh.at (LINENO): Likewise.
* lib/m4sugar/m4sh.m4 (_AS_BOURNE_COMPATIBLE)
(_AS_DETECT_BETTER_SHELL, _AS_SHELL_SANITIZE)
(_AS_PATH_SEPARATOR_PREPARE): Likewise.
(AS_VAR_TEST_SET): Use shorter sequence.
Signed-off-by: Eric Blake <eblake@redhat.com>
This follows up on a comment by Glenn Morris in:
http://lists.gnu.org/archive/html/emacs-devel/2015-01/msg00011.html
* doc/autoconf.texi (Limitations of Usual Tools):
Remove circa-1990 advice about avoiding cp -f and ln -f.
Although that advice was reasonable for the early 1990s, the -f
option is portable for both cp and ln nowadays. These options
were standardized in POSIX 1003.2-1992, and pre-POSIX systems such
as SunOS 4 are no longer of practical concern.
There has been a LOT of news about bash's Shell Shock bug lately.
Document some of the ramifications it has on portable scripting.
* doc/autoconf.texi (Limitations of Builtins) <export>: Add some
details about Shell Shock CVE-2014-6271.
Signed-off-by: Eric Blake <eblake@redhat.com>
* doc/autoconf.texi (C Compiler, Objective C Compiler)
(Objective C++ Compiler, Fortran Compiler): Be more careful about
distinguishing GNU C from GCC, and similarly for other languages.
Problem reported by Marko Lindqvist in:
http://lists.gnu.org/archive/html/autoconf/2014-09/msg00027.html
* lib/autoconf/c.m4 (AC_C_VARARRAYS): Define __STDC_NO_VLA__ if
VLAs are not supported, as this is what C11 does. The old macro
HAVE_C_VARARRAYS is still defined if they are supported, but is
now obsolescent. Also, check for VLA bug in GCC 3.4.3.
* doc/autoconf.texi (C Compiler), NEWS: Document the above.
* doc/autoconf.texi: Specify @documentencoding UTF-8. Don't abuse
'`' to mean open quote, unless Texinfo already interprets it that
way. Be more careful about hyphen versus minus versus endash
versus emdash.
This patch changes "main ()" to "main (void)" for C/C++.
See: http://lists.gnu.org/archive/html/bug-autoconf/2014-01/msg00005.html
On my machine, before this patch, 3 tests were failing:
38: tools.at:1329 autom4te cache locking
218: autotest.at:1893 C unit tests
ac_config_testdir at_tested autotest
219: autotest.at:1948 C unit tests (EXEEXT)
ac_config_testdir at_tested autotest
With this patch, 2 tests were failing:
218: autotest.at:1893 C unit tests
ac_config_testdir at_tested autotest
219: autotest.at:1948 C unit tests (EXEEXT)
ac_config_testdir at_tested autotest
(I suspect that 38 is unrelated.)
Signed-off-by: Vincent Lefevre <vincent@vinc17.net>
Copyright-paperwork-exempt: Yes
The autoconf manual doesn't mention any examples of actually
using m4_pattern_forbid. Yet this is the perfect macro for
avoiding the all-too-common failure mode of configure dying with:
checking if libxml2 is present... ./configure: line 11586: syntax
error
near unexpected token `LIBXML2,'
./configure: line 11586: `PKG_CHECK_MODULES(LIBXML2, libxml-2.0>=
2.6.19,'
for developers that forgot to install pkg-config. While we don't
necessarily advertise the use of PKG_CHECK_MODULES, it is a
common enough situation that the manual should make it easier to
help developers learn about missing third-party macros.
Based on a mailing list report by Daniel Pocock:
http://lists.gnu.org/archive/html/autoconf/2014-01/msg00030.html
* doc/autoconf.texi (Forbidden Patterns): Add examples.
Signed-off-by: Eric Blake <eblake@redhat.com>
Done via 'make update-copyright', since all files are effectively
modified and distributed this year via public version control.
* all files: Update copyright year.
* lib/autoconf/headers.m4 (_AC_INCLUDES_DEFAULT_REQUIREMENTS):
Include stddef.h, stdlib.h, and string.h unconditionally.
Don't include memory.h at all.
Don't use AC_HEADER_STDC.
Don't check for stddef.h, stdlib.h, string.h, or memory.h.
For compatibility, unconditionally define STDC_HEADERS,
HAVE_STDLIB_H, and HAVE_STRING_H.
(AN_HEADER list): Remove C89 headers, and memory.h from list.
(AC_HEADER_STDC, AC_UNISTD_H): AU_DEFUN to trigger
_AC_INCLUDES_DEFAULT_REQUIREMENTS if it hasn't already happened,
and do nothing else.
(AC_HEADER_TIME): AU_DEFUN, and define TIME_WITH_SYS_TIME unconditionally
as long as sys/time.h is present.
(AC_USG, AC_MEMORY_H): Assume existence of string.h.
* lib/autoconf/functions.m4 (_AC_FUNC_MALLOC_IF, _AC_FUNC_REALLOC_IF):
Don't use AC_HEADER_STDC. Assume stdlib.h exists.
(AC_FUNC_MKTIME): Don't use AC_HEADER_TIME. Assume time.h exists.
(AC_FUNC_ALLOCA): Assume stdlib.h exists.
(_AC_LIBOBJ_FNMATCH): Assume wchar.h and wctype.h exist.
(_AC_LIBOBJ_GETLOADAVG): Assume locale.h exists.
(AC_FUNC_MMAP): Assume stdlib.h exists.
* tests/tools.at: Use AC_WORDS_BIGENDIAN instead of AC_STDC_HEADERS in
autoupdate test.
* NEWS, doc/autoconf.texi: Document changes. Remove obsolete advice.
* lib/autoconf/headers.m4 (AC_CHECK_HEADER): Use _AC_CHECK_HEADER_COMPILE
by default. Continue to use _AC_CHECK_HEADER_PREPROC if fourth arg is '-'.
(_AC_CHECK_HEADER_PREPROC): Issue a deprecation warning.
(_AC_CHECK_HEADER_MONGREL, _AC_CHECK_HEADER_MONGREL_BODY): Remove.
* tests/c.at, tests/semantics.at: Update uses of AC_CHECK_HEADER(S).
* doc/autoconf.texi, NEWS: Document change.
http://lwn.net/Articles/436012/ documents that many distros
are now preferring to use /run rather than /var/run for
storage of pid files and other per-process temporary files
that must not be cleaned out during arbitrary TMPDIR sweeps.
As such, the GNU Coding Standards were recently changed to
recommend a new configure option to make it easy to choose
this directory at configure time. This patch adds support
for the option to all configure scripts built by autoconf.
* general.m4 (_AC_INIT_PARSE_ARGS): Add new directory option.
(_AC_INIT_HELP): Document it.
* doc/autoconf.texi (Installation Directory Variables): Document
new option.
(Site Defaults): Mention typical use within a distro.
* NEWS: Mention the addition.
Signed-off-by: Eric Blake <eblake@redhat.com>
Jonathan Lebon reported an issue to me off-list about a regression
in libvirt's configure script, which I traced to a patch that
rearranged code that was checking $with_library compared to the
AC_ARG_WITH that actually set $with_library [1]. As the whole point
of the libvirt patch was to refactor code to make maintenance
easier by hiding the AC_ARG_WITH in a helper macro for a net
reduction in lines, it makes sense to actually document how to
check what value a variable has prior to the AC_ARG_WITH usage.
Alas, although the functionality for this has been present in
autoconf for ages, the documentation has been lacking.
[1] libvirt.org/git/?p=libvirt.git;a=commitdiff;h=654c709
* doc/autoconf.texi (Diversion support) <m4_divert_text>: Add
anchor.
(External Software) <AC_ARG_WITH>: Demonstrate how to use DEFAULTS
diversion, for earlier defaults.
(Package Options) <AC_ARG_ENABLE>: Likewise.
* THANKS: Add Jonathan Lebon.
Signed-off-by: Eric Blake <eblake@redhat.com>
