Paul Eggert [Mon, 11 Dec 2006 06:40:13 +0000 (06:40 +0000)]
* BUGS: Remove mention of VPATH problem, since it's now documented
not to be a bug in the Autoconf build procedure itself, but rather
a problem with the proprietary `make' programs.
* doc/autoconf.texi (Build Directories): Add a cross reference
to VPATH and Make.
* build-aux/config.guess, build-aux/config.sub, build-aux/texinfo.tex:
* doc/standards.texi: Sync from gnulib.
Paul Eggert [Thu, 7 Dec 2006 06:39:40 +0000 (06:39 +0000)]
* lib/autoconf/c.m4 (_AC_PROG_CC_C89): Also try -xc99=all, for Sun
C 5.8 on Solaris 10. Using -xc99=all rather than -xc99 bypasses
the buggy -xc99 option of Forte Developer 7 C on Solaris 9.
Ralf Wildenhues [Thu, 7 Dec 2006 05:16:59 +0000 (05:16 +0000)]
* lib/autoconf/status.m4 (_AC_OUTPUT_FILES_PREPARE): Drop the
`CEOF$ac_eof' special marker, the awk script cannot contain a
line matching `^CEOF', so this is not needed any more.
* tests/torture.at (Substitute a newline): Expose the `%!_!# '
special marker in the test.
Ralf Wildenhues [Tue, 5 Dec 2006 21:36:25 +0000 (21:36 +0000)]
* lib/autoconf/status.m4 (_AC_OUTPUT_FILES_PREPARE): When
creating the awk substitution script, handle one input line at a
time, so that the maximum length of a substituted (multi-line)
value is not limited by the size of the sed pattern space.
The trade-off is a slightly repetitive sed script.
* doc/autoconf.texi (Limitations of Usual Tools): Branch labels
can only have up to 7 characters, due to Solaris 10 /bin/sed.
* tests/torture.at (Substitute a 2000-byte string): Increase the
test with several long lines, they should not be caught by sed
limits any more.
Ralf Wildenhues [Tue, 5 Dec 2006 18:57:06 +0000 (18:57 +0000)]
* tests/torture.at (Substitute a 2000-byte string): Actually use
AC_PROG_AWK, so the last change works as intended.
(Substitute and define special characters): Likewise.
(Substitute a newline): Likewise.
Ralf Wildenhues [Tue, 5 Dec 2006 06:00:42 +0000 (06:00 +0000)]
* lib/autoconf/status.m4 (_AC_OUTPUT_FILES_PREPARE): Use `$AWK'
instead of `awk' consistently.
(_AC_OUTPUT_CONFIG_STATUS): Initialize $AWK.
* tests/torture.at (Torturing config.status): Test both the
result of AC_PROG_AWK and plain awk.
(Substitute a 2000-byte string): Likewise.
(Substitute and define special characters): Likewise.
(Substitute a newline): Likewise.
Paul Eggert [Mon, 4 Dec 2006 23:54:25 +0000 (23:54 +0000)]
* lib/autoconf/functions.m4 (AC_FUNC_FSEEKO): Check that fseeko
can be assigned to a function pointer. Problem reported by
Peter Palfrader in <http://bugs.debian.org/401377>. Based on
part of a patch by Ralf Wildenhues in that same bug report.
Paul Eggert [Fri, 1 Dec 2006 19:21:03 +0000 (19:21 +0000)]
* lib/autoconf/c.m4 (AC_LANG_INT_SAVE): Avoid newline, to aid in
cross-compiling from cygwin to mingw.
Reported by Bob Rossi. This resurrects the 2000-11-30 patch to
aclang.m4, which was mistakenly removed in the 2001-09-17 patch
to lib/autoconf/c.m4.
Paul Eggert [Fri, 1 Dec 2006 18:32:34 +0000 (18:32 +0000)]
* lib/m4sugar/m4sh.m4 (_AS_ECHO_PREPARE): Use a longer test
string for more reliable failure. Wrap the entire test that
causes the broken Solaris printf to dump core, in a subshell,
so the segmentation fault message is reliably suppressed.
Fix shell expansion errors by using /usr/ucb/echo always;
avoid an error on systems without it by another subshell.
Avoid m4 expansion of `$1'. Set the zeroth argument of the
subshell-$as_echo to `as_echo', for better error message.
Paul Eggert [Tue, 28 Nov 2006 03:29:47 +0000 (03:29 +0000)]
Turn AC_FUNC_SETVBUF_REVERSED into a noop. It's been obsolete for
years and is too hard to maintain now. The last straw was
reported by Jerker Baeck in
<http://lists.gnu.org/archive/html/autoconf/2006-11/msg00102.html>.
* NEWS: AC_FUNC_SETVBUF_REVERSED is now obsolete.
* doc/autoconf.texi (Particular Functions): Move
AC_FUNC_SETVBUF_REVERSED from here...
(Obsolete Macros): ... to here. Say that it does nothing now.
* lib/autoconf/functions.m4 (AC_FUNC_SETVBUF_REVERSED):
Turn into (almost) a no-op.
Paul Eggert [Mon, 27 Nov 2006 22:47:33 +0000 (22:47 +0000)]
* doc/autoconf.texi (Setting Output Variables): Mention that
@VAR1@VAR2 has unspecified behavior. Problem reported by
Ralf Wildenhues.
* NEWS: Mention this.
Paul Eggert [Mon, 27 Nov 2006 21:35:37 +0000 (21:35 +0000)]
* Makefile.am: Put only a single '#' into the copyright notice,
so that it's also present in the output file. Standardize wording
in makefile copyright notices to match GNU coding standards.
* bin/Makefile.am: Likewise.
* doc/Makefile.am: Likewise.
* lib/Makefile.am: Likewise.
* lib/freeze.mk: Likewise.
* lib/autoconf/Makefile.am: Likewise.
* lib/autoscan/Makefile.am: Likewise.
* lib/autotest/Makefile.am: Likewise.
* lib/m4sugar/Makefile.am: Likewise.
* man/Makefile.am: Likewise.
* tests/Makefile.am: Likewise.
* lib/emacs/Makefile.am: Remove copyright notice; it's just a
one-line file.
Ralf Wildenhues [Mon, 27 Nov 2006 18:59:43 +0000 (18:59 +0000)]
* lib/autoconf/status.m4 (_AC_OUTPUT_FILES_PREPARE): Fix error
in the sed script that mangles the awk script: delete up to the
first exclamation mark only.
* tests/torture.at (Substitute and define special characters):
Test '!' too.
Paul Eggert [Sun, 26 Nov 2006 17:53:10 +0000 (17:53 +0000)]
Rewrite config files generation: avoid quadratic growth in
the number of substituted variables by using awk instead of sed
for the bulk of the substitutions.
* NEWS: Mention this.
* doc/autoconf.texi (Setting Output Variables): `|#_!!_#|' is also
forbidden in the output (and thus input) file.
* lib/autoconf/status.m4 (_AC_AWK_LITERAL_LIMIT): New macro.
(_AC_OUTPUT_FILES_PREPARE): Instead of several sed scripts,
generate just one large awk script for substitutions,
eliminating much of the earlier complexity, while adding some
new complexity. Only expand the substitution templates at
configure time, for smaller configure script size. If
_AC_SUBST_FILES are used, test 'awk' for working getline support
at config.status time. If absent, interpolate through the
shell. The awk script was written with much help
from Paolo Bonzini and Paul Eggert.
(_AC_SED_CMD_NUM, _AC_SED_DELIM_NUM, _AC_SED_FRAG): Removed.
(_AC_SED_FRAG_NUM): Likewise.
(_AC_SUBST_CMDS): Renamed from...
(_AC_SED_CMDS): ...this.
(_AC_OUTPUT_FILE): Use _AC_SUBST_CMDS.
* tests/torture.at (Substitute a 2000-byte string): Also
substitute a line with 1000 words, and a variable with several
long lines.
(Substitute and define special characters): Test awk special
characters, and put substitution input strings `@foo@' in the
output, to test that no recursion happens; test several other
combinations from Paolo Bonzini.
Paul Eggert [Sat, 25 Nov 2006 09:57:34 +0000 (09:57 +0000)]
* lib/autotest/general.m4 (AT_INIT): Undo recent changes
that replaced echo with AS_ECHO where this wasn't necessary.
Problem reportd by Ralf Wildenhues.
* lib/m4sugar/m4sh.m4 (_AS_ECHO_PREPARE): Port to Solaris 7,
where "/usr/bin/printf '%s\n' S" dumps core if S is long.
This is Sun bug 4206210. Problem reportd by Ralf Wildenhues.
Paul Eggert [Tue, 21 Nov 2006 17:29:01 +0000 (17:29 +0000)]
* doc/autoconf.texi (Limitations of Usual Tools): Don't claim
that traditional Awk lacks 3-arg "split". It has it.
Mention that FS must be a single character, and a few other
99-byte limits of traditional Awk.
Paul Eggert [Sun, 19 Nov 2006 01:14:34 +0000 (01:14 +0000)]
* tests/autotest.at (BSx641-newline in command):
(BS-BS-newline in command, BSx640-newline in command):
(Newline-CODE-BS-newline in command):
(Single-quote-BS-newline in command):
(Single-quote-newline-BS-newline in command):
Use printf '%s\n' instead of echo, for portability to hosts
where echo interprets backslashes. This will break on hosts
that lack printf, but for now let's assume all such hosts
are dead (if not, we should get reports of test failures).
Paul Eggert [Fri, 17 Nov 2006 21:04:54 +0000 (21:04 +0000)]
'echo' has some portability problems, when given a first argument
with a leading '-', or when given any argument containing '\'.
Avoid using 'echo' in these cases.
* bin/Makefile.am $(bin_SCRIPTS): Rewrite to avoid 'echo' entirely.
* lib/autoconf/c.m4 (AC_PROG_CC, AC_PROG_CXX, AC_PROG_OBJC): Likewise.
* lib/autoconf/fortran.m4 (_AC_PROG_FC): Likewise.
* lib/autotest/general.m4 (AT_INIT): Likewise.
* bin/autoconf.as: Use AS_ECHO rather than plain echo, when the
argument might be unportable.
* lib/autoconf/c.m4 (AC_PROG_CC_C_O): Likewise.
* lib/autoconf/erlang.m4 (AC_LANG(Erlang)): Likewise.
* lib/autoconf/fortran.m4 (_AC_PROG_FC_V_OUTPUT):
(_AC_FC_LIBRARY_LDFLAGS): Likewise.
* lib/autoconf/functions.m4 (AC_FUNC_GETLOADAVG): Likewise.
* lib/autoconf/general.m4 (_AC_INIT_PARSE_ENABLE, _AC_INIT_PREPARE):
(_AC_ARG_VAR_VALIDATE, AC_ARG_PROGRAM, _AC_MSG_LOG_CONFTEST):
(AC_RUN_LOG, _AC_RUN_IFELSE, _AC_LIBOBJS_NORMALIZE): Likewise.
* lib/autoconf/lang.m4 (_AC_COMPILER_EXEEXT_DEFAULT): Likewise.
* lib/autoconf/libs.m4 (_AC_PATH_X_DIRECT): Likewise.
* lib/autoconf/programs.m4 (_AC_FEATURE_CHECK_LENGTH):
(AC_PROG_MAKE_SET): Likewise.
* lib/autoconf/status.m4 (_AC_SRCDIRS, _AC_OUTPUT_HEADER):
(_AC_OUTPUT_SUBDIRS, _AC_OUTPUT_CONFIG_STATUS): Likewise.
* lib/autotest/general.m4 (_AT_CREATE_DEBUGGING_SCRIPT, AT_INIT):
(AT_CLEANUP, _AT_DECIDE_TRACEABLE, _AT_CHECK): Likewise.
* lib/m4sugar/m4sh.m4 (AS_SHELL_SANITIZE, _AS_ECHO_UNQUOTED):
(_AS_BASENAME_SED, _AS_DIRNAME_SED, AS_MKDIR_P, AS_TMPDIR, AS_UNAME):
(AS_TR_SH, AS_TR_CPP, AS_VAR_GET): Likewise.
* bin/autoconf.as: Redo verbose flag implementation, as the old
scheme wouldn't work with AS_ECHO.
* lib/autotest/general.m4 (AT_INIT): Likewise.
* lib/autoconf/general.m4 (AC_MSG_RESULT, AC_MSG_RESULT_UNQUOTED):
Don't use ECHO_T, since ECHO_N is now reliable.
* lib/autotest/general.m4 (AT_INIT): Likewise.
* lib/autoconf/general.m4 (AC_ARG_PROGRAM): Use sed "$script"
rather than using a here-document to put the script into a file.
(_AC_DO_ECHO): Hoist the eval out of the echo, so that we can
use AS_ECHO.
* lib/m4sugar/m4sh.m4 (AS_VAR_GET): Likewise.
* lib/autoconf/programs.m4 (_AC_FEATURE_CHECK_LENGTH): Use
AS_ECHO_N rather than ECHO_N and ECHO_C. This doesn't fix any
bug, but we might as well stop using ECHO_N and ECHO_C internally.
* lib/autotest/general.m4 (AT_SETUP): Likewise.
* lib/m4sugar/m4sh.m4 (_AS_ECHO_N): Likewise.
* lib/autoconf/status.m4 (_AC_OUTPUT_CONFIG_STATUS):
(_AC_OUTPUT_MAIN_LOOP): Rework echo so that it has just one
operand, as AS_ECHO requires. Avoid double file name expansion.
* lib/m4sugar/m4sh.m4 (AS_SHELL_SANITIZE): Invoke _AS_ECHO_PREPARE.
Don't set as_nl, since _AS_ECHO_PREPARE does that now.
(_AS_PREPARE): Comment that _AS_ECHO_N_PREPARE is just for user code.
(AS_ECHO, AS_ECHO_N, _AS_ECHO_PREPARE): New macros.
* tests/c.at (AC_PROG_CPP without warnings, AC_PROG_CPP via CC):
Double-quote strings that would otherwise contain M4 comments.
* tests/m4sh.at (AS_ECHO and AS_ECHO_N): New test.
Paul Eggert [Fri, 17 Nov 2006 09:17:38 +0000 (09:17 +0000)]
* tests/autotest.at (Macro with backslash in a test title):
Comment out for now, as this tests neither fails nor passes
reliably. Problem reported by Ralf Wildenhues.
Paul Eggert [Fri, 17 Nov 2006 00:16:27 +0000 (00:16 +0000)]
* lib/autoconf/general.m4 (_AC_INIT_PARSE_ARGS): Factor out
code for --enable, --disable, --with, and --without to...
(_AC_INIT_PARSE_ENABLE): ... a new macro.
* doc/autoconf.texi (Package Options):
* NEWS: Document that AC_ARG_ENABLE allows dots, too.
Paul Eggert [Mon, 13 Nov 2006 20:40:06 +0000 (20:40 +0000)]
* NEWS: Document the AC_ARG_WITH change.
2006-11-13 Bruno Haible <bruno@clisp.org>
* lib/autoconf/general.m4 (_AC_INIT_PARSE_ARGS): For --with, --without
options, transliterate also dots to underscores.
(_AC_ENABLE_IF): Transliterate also dots to underscores.
* doc/autoconf.texi (External Software): Document that AC_ARG_WITH's
first argument may also contain dots.
Paul Eggert [Thu, 9 Nov 2006 21:03:54 +0000 (21:03 +0000)]
* tests/mktests.sh (ac_exclude_list): Exclude AC_PROG_CXX_C_O, for
benefit of platforms like Solaris+GCC where it is common to have a
non-working g++ installation.
Paul Eggert [Wed, 8 Nov 2006 21:44:32 +0000 (21:44 +0000)]
* lib/autoconf/types.m4 (AC_TYPE_LONG_LONG_INT): Set
ac_cv_type_long_long_int to 'yes' instead of 'cross-compiling'.
Imported from a similar patch to gnulib by Bruno Haible.
Paul Eggert [Fri, 27 Oct 2006 23:05:33 +0000 (23:05 +0000)]
Handle special characters in test case titles correctly.
* lib/autotest/general.m4 (AT_INIT): M4-quote and AS_ESCAPE AT_help_all
properly.
(AT_SETUP): M4-quote and AS_ESCAPE the title properly everywhere.
* tests/autotest.at (AT_CHECK_AT_TITLE): Add EXPANDED-TITLE-TO-TEST
argument. Extend to check titles printed by ./micro-suite and
./micro-suite -l and the title in micro-suite.log.
(Backquote in a test title,
Single-quote in a test title,
Double-quote in a test title): Don't expect failure anymore.
(Backslash in a test title): Put a non-whitespace character after the
backslash so that Bourne shells might actually see it as an escape
sequence.
(Brackets in a test title,
Pound in a test title,
Comma in a test title,
Quoted Macro in a test title,
Macro in a test title,
Macro with single-quote in a test title): New tests.
(Macro with backquote in a test title,
Macro with double-quote in a test title,
Macro with backslash in a test title): New tests expected to fail.
* tests/torture.at (#define header templates): M4-quote this title in
AT_SETUP call so that no M4 code is commented inadvertently somewhere.
The visible effect was a stray [] in the testsuite output.
Paul Eggert [Thu, 26 Oct 2006 19:30:32 +0000 (19:30 +0000)]
* tests/base.at (AC_COMPUTE_INT): Test **0** rather than 1 / 0,
since powerpc-apple-darwin8-gcc-4.0.1 (Apple Computer, Inc. build
5363) simply issues a warning when dividing by zero at compile
time. Problem reported by Elias Pipping.
Eric Blake [Thu, 26 Oct 2006 16:32:11 +0000 (16:32 +0000)]
* THANKS: Update.
* doc/autoconf.texi (Evaluation Macros): Improve the example to
show effect on macros that expand with commas.
Reported by Joel E. Denny.
Eric Blake [Thu, 26 Oct 2006 16:32:11 +0000 (16:32 +0000)]
* THANKS: Update.
* doc/autoconf.texi (Evaluation Macros): Improve the example to
show effect on macros that expand with commas.
Reported by Joel E. Denny.
Paul Eggert [Tue, 24 Oct 2006 19:34:09 +0000 (19:34 +0000)]
* lib/autoconf/specific.m4 (_AC_SYS_LARGEFILE_MACRO_VALUE):
If FUNCTION-BODY is nonempty, use AC_LINK_IFELSE rather than
AC_COMPILE_IFELSE, to work around problem with OSF/1 4.0F fseeko
reported by Nelson H. F. Beebe for Coreutils 6.4.
Paul Eggert [Mon, 23 Oct 2006 06:12:40 +0000 (06:12 +0000)]
* NEWS: Remove AC_CACHE_CHECK_INT.
* doc/autoconf.texi (Caching Results): Likewise.
* lib/autoconf/general.m4 (_AC_CACHE_CHECK_INT): Renamed from
AC_CACHE_CHECK_INT, since it's no longer public.
* lib/autoconf/types.m4: All uses of AC_CACHE_CHECK_INT changed.
* tests/base.at (AC_COMPUTE_INT): Test this, not AC_CACHE_CHECK_INT.
Paul Eggert [Sun, 15 Oct 2006 01:12:02 +0000 (01:12 +0000)]
* lib/m4sugar/m4sh.m4 (AS_LITERAL_IF): Expand $1 before
looking for special shell characters.
* lib/autoconf/functions.m4 (AC_CHECK_FUNC): Do not expand the
macro defined by AS_VAR_PUSHDEF before passing it as a
parameter.
* lib/autoconf/general.m4 (AC_CHECK_FILE, AC_CHECK_DECL):
* lib/autoconf/libs.m4 (AC_SEARCH_LIBS, AC_CHECK_LIB):
* lib/autoconf/types.m4 (_AC_CHECK_TYPE_NEW, AC_CHECK_MEMBER):
* lib/autoconf/headers.m4 (_AC_CHECK_HEADER_MONGREL):
(_AC_CHECK_HEADER_NEW, _AC_CHECK_HEADER_OLD, _AC_CHECK_HEADER_DIRENT):
Likewise.
* lib/autotest/general.m4 (AT_INIT): Quote parameters of
AS_VAR_* properly.
* tests/m4sh.at (AS_LITERAL_IF): New test.
Paul Eggert [Sun, 15 Oct 2006 00:58:25 +0000 (00:58 +0000)]
(Imported from Automake.)
* build-aux/install-sh (posix_mkdir): Reject FreeBSD 6.1 mkdir -p -m,
which incorrectly sets the mode of an existing destination
directory. In some cases the unpatched install-sh could do the
equivalent of "chmod 777 /" or "chmod 0 /" on a buggy FreeBSD
system. We hope this is rare in practice, but it's clearly worth
fixing. Problem reported by Alex Unleashed in
<http://lists.gnu.org/archive/html/bug-autoconf/2006-10/msg00012.html>.
Also, don't bother to check for -m bugs unless we're using -m;
suggested by Stepan Kasal.
2006-10-14 Paul Eggert <eggert@cs.ucla.edu>
Import this change from Automake:
2006-08-23 Alexandre Duret-Lutz <adl@gnu.org>
* lib/Autom4te/ChannelDefs.pm (usage): Mention that -Wportability
is enabled by default with gnu and gnits strictness.
Report from Bruno Haible.
2006-03-10 Alexandre Duret-Lutz <adl@gnu.org>
* lib/Autom4te/ChannelDefs.pm: Make -Wportability the default in
gnu and gnits modes.
Import this change from Config:
2006-09-20 Ben Elliston <bje@gnu.org>
* build-aux/config.sub (score, score-*): New.
Import this change from Gnulib:
2006-09-16 Karl Berry <karl@gnu.org>
* doc/fdl.texi (ADDENDUM): switch to @heading from @appendixsubsec,
to avoid sectioning errors.
Import these changes from Texinfo:
2006-10-04 Karl Berry <karl@gnu.org>
* build-aux/texinfo.tex (\singlequotechar): rename to \codequoteright.
(\quoteexpand): rename to \rquoteexpand.
(\codequoteleft): new def, to look for @set codequotebacktick.
(\lquoteexpand, \quoteexpand): new defs.
(\lquoteChar, \rquoteChar, \dashChar, \underChar: new \chardef's.
(\code): must use new \...Char values, since now ` is active.
2006-08-26 Karl Berry <karl@gnu.org>
* build-aux/texinfo.tex (\textdegree): New command.
2006-08-12 Karl Berry <karl@gnu.org>
* build-aux/texinfo.tex (error \box0): smaller font.
Ralf Wildenhues [Fri, 13 Oct 2006 05:19:20 +0000 (05:19 +0000)]
* lib/autoconf/functions.m4 (AC_FUNC_OBSTACK): In the test,
include the default headers, and redefine obstack_chunk_alloc
and obstack_chunk_free. Fixes false failure with glibc.
Paul Eggert [Wed, 11 Oct 2006 21:50:57 +0000 (21:50 +0000)]
* lib/m4sugar/m4sh.m4 (AS_TEST_X): New macro.
(AS_EXECUTABLE_P): Use as_test_x rather than as_executable_p.
(_AS_TEST_PREPARE): Set as_test_x rather than as_executable_p.
Use a better substitute, by inspecting the output of "ls"
rather than just using ":".
* lib/autoconf/general.m4 (_AC_LINK_IFELSE): Use AS_TEST_X
rather than AS_EXECUTABLE_P, since we needn't worry about
non-regular files here.
Paul Eggert [Wed, 11 Oct 2006 19:35:57 +0000 (19:35 +0000)]
* NEWS: Autoconf-generated shell scripts no longer export BIN_SH,
due to configuration hassles with this. See Tonya Underwood's report
<http://lists.gnu.org/archive/html/bug-autoconf/2006-10/msg00003.html>.
* doc/autoconf.texi (Special Shell Variables): Likewise.
2006-10-11 Paul Eggert <eggert@cs.ucla.edu>
Stepan Kasal <kasal@ucw.cz>
* lib/m4sugar/m4sh.m4 (AS_BOURNE_COMPATIBLE): Don't set BIN_SH.
(_AS_DETECT_BETTER_SHELL): Don't look in /usr/bin/posix.
2006-10-11 Stepan Kasal <kasal@ucw.cz>
* lib/m4sugar/m4sh.m4 (AS_BOURNE_COMPATIBLE): Move the
initialization which is not inherited through the environment
(_AS_BOURNE_COMPATIBLE): ... to this new macro.
(_AS_RUN): Call _AS_BOURNE_COMPATIBLE, not AS_BOURNE_COMPATIBLE.
Paul Eggert [Fri, 6 Oct 2006 17:43:55 +0000 (17:43 +0000)]
* lib/autoconf/c.m4 (_AC_PROG_PREPROC_WORKS_IFELSE): Remove
comment about ac_cpp_err; it was incorrect, and anyway
ac_cpp_err is being removed below.
* lib/autoconf/general.m4 (_AC_PREPROC_IFELSE): Don't
set ac_cpp_err to 'yesyes' if preproc_warn_flag and werror_flag
are both 'yes'. In fact, don't bother setting ac_cpp_err at all;
nobody uses it.
(_AC_COMPILE_IFELSE, _AC_LINK_IFELSE): Don't log our funky tests
with werror_flag and conftest.err and so forth. This is more
compatible with how _AC_PROG_PREPROC_WORKS_IFELSE behaves,
and anyway the user shouldn't normally want to see this gorp logged.
Problem reported by Ralf Wildenhues.
* lib/autoconf/lang.m4 (AC_LANG_WERROR): werror_flag's default is
empty, not 'no', since the rest of the code uses 'test -z'.