Rather than perform a sed script on each element of the
$ac_func_c_list to compute the corresponding CPP name, we can
make the list store a series of pairs of function names and
CPP names all computed at m4 time.
The resulting configure script is slightly larger based on
how many function names are checked once, but also performs
slightly faster.
There is still a sed call in AC_CHECK_FUNC for computing the
cache variable name; that will be dealt with next.
* lib/autoconf/functions.m4 (_AC_CHECK_FUNC_ONCE): Track the CPP
name in the list...
(_AC_FUNCS_EXPANSION): ...and rewrite the list walk to parse off
pairs of arguments, for fewer sed calls.
Signed-off-by: Eric Blake <eblake@redhat.com>
Previously, AC_CHECK_HEADERS_ONCE collected a list of header names
to check, but ran the checks using the AC_LANG that was active
during the first encounter of the macro. In practice, this is
usually the C language, and we haven't had actual reports of projects
attempting to use AC_CHECK_HEADERS_ONCE across multiple languages,
rather this was discovered by code inspection.
With this patch, the code now tracks a separate per-language list of
names to check. Note, however, that it is only possible to check for
a given header name in one language; attempting to add a name again
under AC_CHECK_HEADERS_ONCE while a different language is active is a
no-op (this still makes sense because the side-effect of defining
the CPP macro HAVE_HEADER does not include a language prefix).
* lib/autoconf/headers.m4 (_AC_CHECK_HEADER_ONCE)
(_AC_HEADERS_EXPANSION):
* NEWS: Mention it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Previously, AC_CHECK_FUNCS_ONCE collected a list of function names
to check, but ran the checks using the AC_LANG that was active
during the first encounter of the macro. In practice, this is
usually the C language, and we haven't had actual reports of projects
attempting to use AC_CHECK_FUNCS_ONCE across multiple languages,
rather this was discovered by code inspection.
With this patch, the code now tracks a separate per-language list of
names to check. Note, however, that it is only possible to check for
a given function name in one language; attempting to add a name again
under AC_CHECK_FUNCS_ONCE while a different language is active is a
no-op (this still makes sense because the side-effect of defining
the CPP macro HAVE_FUNC does not include a language prefix).
* lib/autoconf/functions.m4 (_AC_CHECK_FUNC_ONCE)
(_AC_FUNCS_EXPANSION):
* NEWS: Mention it.
Signed-off-by: Eric Blake <eblake@redhat.com>
It is a very common case that a quadrigraph appears in the argument of
_AC_DEFINE_UNQUOTED, because "#define" is expanded through a quadrigraph.
Therefore, restrict the quadrigraph tests to "$" (for "$(" and "${")
and "(" (for "$(").
At the same time, "#" should not be used inside AC_ECHO because it confuses
m4's comment parsing. This pre-existing latent bug is caught by test 251:
AC_DEFINE_UNQUOTED([bar], [[%!_!# X]])
Previously the quadrigraph in "@%:@define bar %!_!# X" made Autoconf fall back
to cat anyway. Now that Autoconf is not fooled by the quadrigraph, the test
catches that "#" is not special-cased. Kudos to Eric for coming up with it!
* lib/autoconf/general (_AC_DEFINE_UNQUOTED): Do not blindly
use cat on all quadrigraphs.
Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
Message-Id: <1477933688-4884-4-git-send-email-bonzini@gnu.org>
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>
* bin/autom4te.in (handle_traces): When $output is '-', use
stdout rather than creating a file named '-'. This fixes a problem
introduced by the recent port to the new Autom4te::XFile API.
Problem reported by Václav Zeman in:
http://lists.gnu.org/archive/html/autoconf/2012-10/msg00000.html
* lib/autoconf/c.m4 (AC_PROG_CC, AC_PROG_OBJC): Also try clang.
(AC_PROG_CXX): Also try clang++.
These are at the end of the existing lists, to avoid compatibility
issues in older installations.
Based on a report by Michael Felt, via Paul Eggert on the
coreutils list.
* doc/autoconf.texi (Limitations of Builtins) <for>: Document
problem with 'for var in ;'.
Signed-off-by: Eric Blake <eblake@redhat.com>
* lib/autoconf/general.m4 (_AC_UNDECLARED_WARNING): New macro.
(_AC_CHECK_DECL_BODY): Call it once per language; treat warnings as
errors when its verdict indicates that.
* tests/semantics.at (AC_CHECK_DECLS): Add a macro call that relies on
the new semantics. Avoid -Wmissing-variable-declarations warnings.
* doc/autoconf.texi (Generic Declarations): Document the implications.
* NEWS: Mention this change.
Give a more concrete description of what the m4_pattern_forbid
thingy that pretends it is a macro accepts as an argument.
Copyright-paper-exempt: Yes
Signed-off-by: Eric Blake <eblake@redhat.com>
Based on an idea by Bernhard Reutner-Fischer.
We frequently used the idiom of 'test "${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>
As a minor optimization, most macros in m4sugar.m4 try to avoid
output of 'dnl' in the expansion, to reduce the number of macros
that must be expanded at each call site.
* lib/m4sugar/m4sugar.m4 (m4_set_foreach): Don't expand dnl in all
callers.
Signed-off-by: Eric Blake <eblake@redhat.com>
Merging two case globs into one gives slightly smaller files and
less time spent in shell globbing on systems that lack GNU mkdir.
* lib/autoconf/programs.m4 (AC_PROG_MKDIR_P): Combine two GNU cases.
Signed-off-by: Eric Blake <eblake@redhat.com>
* tests/local.mk (check-local): Add a leading "+",
to void false-positive test failures when running
them in parallel. Before this change, running e.g.,
"make check TESTSUITEFLAGS=--jobs=15" would always
fail the two "make"-invoking tests: "C unit tests"
and "C unit tests (EXEEXT)".
(installcheck-local): Likewise for "installcheck".
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.
The testsuite used slightly different logic in the code employed to
decide whether a test should be skipped due to a limitation of the
selected shell, and in the code running the test itself.
* tests/autotest.at (Syntax error): Adjust.
(parallel syntax error): Likewise.
Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>
Based on a report by Bruce Dubbs.
* tests/foreign.at (Libtool): Be tolerant of 'quote' replacing the
older `quote'.
Signed-off-by: Eric Blake <eblake@redhat.com>
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
