@defmac AC_PROG_AWK
@acindex{PROG_AWK}
@ovindex AWK
+@caindex prog_AWK
Check for @code{gawk}, @code{mawk}, @code{nawk}, and @code{awk}, in that
order, and set output variable @code{AWK} to the first one that is found.
It tries @code{gawk} first because that is reported to be the
-best implementation.
+best implementation. The result is cached in the @code{ac_cv_prog_AWK}
+variable.
@end defmac
@defmac AC_PROG_GREP
@acindex{PROG_GREP}
@ovindex GREP
+@caindex prog_GREP
Look for the best available @code{grep} or @code{ggrep} that accepts the
longest input lines possible, and that supports multiple @option{-e} options.
Set the output variable @code{GREP} to whatever is chosen.
@xref{grep, , Limitations of Usual Tools}, for more information about
-portability problems with the @command{grep} command family.
+portability problems with the @command{grep} command family. The result
+is cached in the @code{ac_cv_path_GREP} variable.
@end defmac
@defmac AC_PROG_EGREP
@acindex{PROG_EGREP}
@ovindex EGREP
+@caindex prog_EGREP
Check whether @code{$GREP -E} works, or else look for the best available
@code{egrep} or @code{gegrep} that accepts the longest input lines possible.
-Set the output variable @code{EGREP} to whatever is chosen.
+Set the output variable @code{EGREP} to whatever is chosen. The result
+is cached in the @code{ac_cv_path_EGREP} variable.
@end defmac
@defmac AC_PROG_FGREP
@acindex{PROG_FGREP}
@ovindex FGREP
+@caindex prog_FGREP
Check whether @code{$GREP -F} works, or else look for the best available
@code{fgrep} or @code{gfgrep} that accepts the longest input lines possible.
-Set the output variable @code{FGREP} to whatever is chosen.
+Set the output variable @code{FGREP} to whatever is chosen. The result
+is cached in the @code{ac_cv_path_FGREP} variable.
@end defmac
@defmac AC_PROG_INSTALL
@ovindex INSTALL_PROGRAM
@ovindex INSTALL_DATA
@ovindex INSTALL_SCRIPT
+@caindex path_install
Set output variable @code{INSTALL} to the name of a @acronym{BSD}-compatible
@command{install} program, if one is found in the current @env{PATH}.
Otherwise, set @code{INSTALL} to @samp{@var{dir}/install-sh -c},
not found in standard @command{install} programs, there is no reason to use
@code{AC_PROG_INSTALL}; just put the file name of your program into your
@file{Makefile.in} files.
+
+The result of the test is cached in the @code{ac_cv_path_install} variable,
+if an @command{install} program other than the in-tree script is found.
@end defmac
@defmac AC_PROG_MKDIR_P
@acindex{PROG_MKDIR_P}
@ovindex MKDIR_P
+@caindex path_mkdir
Set output variable @code{MKDIR_P} to a program that ensures that for
each argument, a directory named by this argument exists, creating it
and its parent directories if needed, and without race conditions when
@samp{@@MKDIR_P@@} is special, as its value may vary for different
configuration files.
+
+The result of the test is cached in the @code{ac_cv_path_mkdir} variable,
+if a @command{mkdir} program other than an in-tree script is found.
@end defmac
@anchor{AC_PROG_LEX}
@ovindex LEXLIB
@cvindex YYTEXT_POINTER
@ovindex LEX_OUTPUT_ROOT
+@caindex prog_LEX
If @code{flex} is found, set output variable @code{LEX} to @samp{flex}
and @code{LEXLIB} to @option{-lfl}, if that library is in a standard
place. Otherwise set @code{LEX} to @samp{lex} and @code{LEXLIB} to
As part of running the test, this macro may delete any file in the
configuration directory named @file{lex.yy.c} or @file{lexyy.c}.
+
+The result of this test is cached in the @code{ac_cv_prog_LEX} variable.
@end defmac
@anchor{AC_PROG_LN_S}
@defmac AC_PROG_RANLIB
@acindex{PROG_RANLIB}
@ovindex RANLIB
+@c @caindex prog_RANLIB
+@c @caindex prog_ac_ct_RANLIB
Set output variable @code{RANLIB} to @samp{ranlib} if @code{ranlib}
is found, and otherwise to @samp{:} (do nothing).
@end defmac
@defmac AC_PROG_SED
@acindex{PROG_SED}
@ovindex SED
+@caindex prog_SED
Set output variable @code{SED} to a Sed implementation that conforms to
Posix and does not have arbitrary length limits. Report an error if no
acceptable Sed is found. @xref{sed, , Limitations of Usual Tools}, for more
information about portability problems with Sed.
+
+The result of this test is cached in the @code{ac_cv_prog_SED} variable.
@end defmac
@defmac AC_PROG_YACC
@evindex YACC
@evindex YFLAGS
@ovindex YACC
+@caindex prog_YACC
If @code{bison} is found, set output variable @code{YACC} to @samp{bison
-y}. Otherwise, if @code{byacc} is found, set @code{YACC} to
@samp{byacc}. Otherwise set @code{YACC} to @samp{yacc}.
+The result of this test is cached in the @code{ac_cv_prog_YACC} variable.
@end defmac
@node Generic Programs
@var{value-if-found}, @ovar{value-if-not-found}, @dvar{path, $PATH}, @
@ovar{reject})
@acindex{CHECK_PROG}
+@caindex prog_@var{variable}
Check whether program @var{prog-to-check-for} exists in @var{path}. If
it is found, set @var{variable} to @var{value-if-found}, otherwise to
@var{value-if-not-found}, if given. Always pass over @var{reject} (an
that case, set @var{variable} using the absolute file name of the
@var{prog-to-check-for} found that is not @var{reject}. If
@var{variable} was already set, do nothing. Calls @code{AC_SUBST} for
-@var{variable}.
+@var{variable}. The result of this test is cached in the
+@code{ac_cv_prog_@var{variable}} variable.
@end defmac
@anchor{AC_CHECK_PROGS}
@defmac AC_CHECK_PROGS (@var{variable}, @var{progs-to-check-for}, @
@ovar{value-if-not-found}, @dvar{path, $PATH})
@acindex{CHECK_PROGS}
+@caindex prog_@var{variable}
Check for each program in the blank-separated list
@var{progs-to-check-for} existing in the @var{path}. If one is found, set
@var{variable} to the name of that program. Otherwise, continue
checking the next program in the list. If none of the programs in the
list are found, set @var{variable} to @var{value-if-not-found}; if
@var{value-if-not-found} is not specified, the value of @var{variable}
-is not changed. Calls @code{AC_SUBST} for @var{variable}.
+is not changed. Calls @code{AC_SUBST} for @var{variable}. The result of
+this test is cached in the @code{ac_cv_prog_@var{variable}} variable.
@end defmac
@defmac AC_CHECK_TARGET_TOOL (@var{variable}, @var{prog-to-check-for}, @
@defmac AC_CHECK_TOOL (@var{variable}, @var{prog-to-check-for}, @
@ovar{value-if-not-found}, @dvar{path, $PATH})
@acindex{CHECK_TOOL}
+@c @caindex prog_@var{VARIABLE}
+@c @caindex prog_ac_ct_@var{VARIABLE}
Like @code{AC_CHECK_PROG}, but first looks for @var{prog-to-check-for}
with a prefix of the host type as specified by @option{--host}, followed by a
dash. For example, if the user runs
@defmac AC_PATH_PROG (@var{variable}, @var{prog-to-check-for}, @
@ovar{value-if-not-found}, @dvar{path, $PATH})
@acindex{PATH_PROG}
+@caindex path_@var{variable}
Like @code{AC_CHECK_PROG}, but set @var{variable} to the absolute
-name of @var{prog-to-check-for} if found.
+name of @var{prog-to-check-for} if found. A positive result of this
+test is cached in the @code{ac_cv_path_@var{variable}} variable.
@end defmac
@anchor{AC_PATH_PROGS}
@defmac AC_PATH_PROGS (@var{variable}, @var{progs-to-check-for}, @
@ovar{value-if-not-found}, @dvar{path, $PATH})
@acindex{PATH_PROGS}
+@caindex path_@var{variable}
Like @code{AC_CHECK_PROGS}, but if any of @var{progs-to-check-for}
are found, set @var{variable} to the absolute name of the program
found.
@var{progs-to-check-for}, @var{feature-test}, @
@ovar{action-if-not-found}, @dvar{path, $PATH})
@acindex{PATH_PROGS_FEATURE_CHECK}
+@caindex path_@var{variable}
This macro was introduced in Autoconf 2.62. If @var{variable} is not
empty, then set the cache variable @code{$ac_cv_path_@var{variable}} to
its value. Otherwise, check for each program in the blank-separated
@defmac AC_CHECK_FILE (@var{file}, @ovar{action-if-found}, @
@ovar{action-if-not-found})
@acindex{CHECK_FILE}
+@caindex file_@var{file}
Check whether file @var{file} exists on the native system. If it is
found, execute @var{action-if-found}, otherwise do
-@var{action-if-not-found}, if given.
+@var{action-if-not-found}, if given. The result of this test is cached
+in the @code{ac_cv_file_@var{file}} variable, with characters not
+suitable for a variable name mapped to underscores.
@end defmac
@defmac AC_CHECK_FILES (@var{files}, @ovar{action-if-found}, @
@ovar{action-if-not-found})
@acindex{CHECK_FILES}
+@caindex file_@var{file}
Executes @code{AC_CHECK_FILE} once for each file listed in @var{files}.
Additionally, defines @samp{HAVE_@var{file}} (@pxref{Standard Symbols})
-for each file found.
+for each file found. The results of each test are cached in the
+@code{ac_cv_file_@var{file}} variable, with characters not suitable for
+a variable name mapped to underscores.
@end defmac
@defmac AC_CHECK_LIB (@var{library}, @var{function}, @
@ovar{action-if-found}, @ovar{action-if-not-found}, @ovar{other-libraries})
@acindex{CHECK_LIB}
+@caindex lib_@var{library}_@var{function}
Test whether the library @var{library} is available by trying to link
a test program that calls function @var{function} with the library.
@var{function} should be a function provided by the library.
contain variant implementations that you may not want to use. These
days it is normally better to use @code{AC_SEARCH_LIBS([gethostbyname],
[nsl])} instead of @code{AC_CHECK_LIB([nsl], [gethostbyname])}.
+
+The result of this test is cached in the
+@code{ac_cv_lib_@var{library}_@var{function}} variable.
@end defmac
@anchor{AC_SEARCH_LIBS}
@defmac AC_SEARCH_LIBS (@var{function}, @var{search-libs}, @
@ovar{action-if-found}, @ovar{action-if-not-found}, @ovar{other-libraries})
@acindex{SEARCH_LIBS}
+@caindex search_@var{function}
Search for a library defining @var{function} if it's not already
available. This equates to calling
@samp{AC_LINK_IFELSE([AC_LANG_CALL([], [@var{function}])])} first with
e.g., @option{-lXt -lX11}. Otherwise, this macro fails to detect
that @var{function} is present, because linking the test program
always fails with unresolved symbols.
+
+The result of this test is cached in the
+@code{ac_cv_search_@var{function}} variable as @samp{no}, if no library
+containing @var{function} was found, otherwise as the
+@option{-l@var{library}} option that needs to be added to @code{LIBS}.
@end defmac
@c @fuindex alloca
@prindex @code{alloca}
@hdrindex{alloca.h}
+@c @caindex working_alloca_h
Check how to get @code{alloca}. Tries to get a builtin version by
checking for @file{alloca.h} or the predefined C preprocessor macros
@code{__GNUC__} and @code{_AIX}. If this macro finds @file{alloca.h},
@cvindex HAVE_CHOWN
@c @fuindex chown
@prindex @code{chown}
+@caindex func_chown_works
If the @code{chown} function is available and works (in particular, it
should accept @option{-1} for @code{uid} and @code{gid}), define
-@code{HAVE_CHOWN}.
+@code{HAVE_CHOWN}. The result of this macro is cached in the
+@code{ac_cv_func_chown_works} variable.
@end defmac
@anchor{AC_FUNC_CLOSEDIR_VOID}
@cvindex CLOSEDIR_VOID
@c @fuindex closedir
@prindex @code{closedir}
+@caindex func_closedir_void
If the @code{closedir} function does not return a meaningful value,
define @code{CLOSEDIR_VOID}. Otherwise, callers ought to check its
return value for an error indicator.
cross compiling the pessimistic assumption that @code{closedir} does not
return a meaningful value is made.
+The result of this macro is cached in the @code{ac_cv_func_closedir_void}
+variable.
+
This macro is obsolescent, as @code{closedir} returns a meaningful value
on current systems. New programs need not use this macro.
@end defmac
@acindex{FUNC_ERROR_AT_LINE}
@c @fuindex error_at_line
@prindex @code{error_at_line}
+@caindex lib_error_at_line
If the @code{error_at_line} function is not found, require an
@code{AC_LIBOBJ} replacement of @samp{error}.
+
+The result of this macro is cached in the @code{ac_cv_lib_error_at_line}
+variable.
@end defmac
@defmac AC_FUNC_FNMATCH
@acindex{FUNC_FNMATCH}
@c @fuindex fnmatch
@prindex @code{fnmatch}
+@caindex func_fnmatch_works
If the @code{fnmatch} function conforms to Posix, define
@code{HAVE_FNMATCH}. Detect common implementation bugs, for example,
the bugs in Solaris 2.4.
broken/missing @code{fnmatch}. This is for historical reasons.
See @code{AC_REPLACE_FNMATCH} below.
+The result of this macro is cached in the @code{ac_cv_func_fnmatch_works}
+variable.
+
This macro is obsolescent. New programs should use Gnulib's
@code{fnmatch-posix} module. @xref{Gnulib}.
@end defmac
@acindex{FUNC_FNMATCH_GNU}
@c @fuindex fnmatch
@prindex @code{fnmatch}
+@caindex func_fnmatch_gnu
Behave like @code{AC_REPLACE_FNMATCH} (@emph{replace}) but also test
whether @code{fnmatch} supports @acronym{GNU} extensions. Detect common
implementation bugs, for example, the bugs in the @acronym{GNU} C
Library 2.1.
+The result of this macro is cached in the @code{ac_cv_func_fnmatch_gnu}
+variable.
+
This macro is obsolescent. New programs should use Gnulib's
@code{fnmatch-gnu} module. @xref{Gnulib}.
@end defmac
@c @fuindex vfork
@prindex @code{vfork}
@hdrindex{vfork.h}
+@c @caindex func_fork
+@c @caindex func_fork_works
This macro checks for the @code{fork} and @code{vfork} functions. If a
working @code{fork} is found, define @code{HAVE_WORKING_FORK}. This macro
checks whether @code{fork} is just a stub by trying to run it.
@prindex @code{fseeko}
@c @fuindex ftello
@prindex @code{ftello}
+@c @caindex sys_largefile_source
If the @code{fseeko} function is available, define @code{HAVE_FSEEKO}.
Define @code{_LARGEFILE_SOURCE} if necessary to make the prototype
visible on some systems (e.g., glibc 2.2). Otherwise linkage problems
@ovindex GETGROUPS_LIBS
@c @fuindex getgroups
@prindex @code{getgroups}
+@caindex func_getgroups_works
If the @code{getgroups} function is available and works (unlike on
Ultrix 4.3, where @samp{getgroups (0, 0)} always fails), define
@code{HAVE_GETGROUPS}. Set @code{GETGROUPS_LIBS} to any libraries
@cvindex HAVE_GETMNTENT
@c @fuindex getmntent
@prindex @code{getmntent}
+@caindex func_getmntent
Check for @code{getmntent} in the standard C library, and then in the
@file{sun}, @file{seq}, and @file{gen} libraries, for @sc{unicos},
@sc{irix} 4, @sc{ptx}, and UnixWare, respectively. Then, if
@code{getmntent} is available, define @code{HAVE_GETMNTENT}.
+
+The result of this macro is cached in the @code{ac_cv_func_getmntent}
+variable.
@end defmac
@defmac AC_FUNC_GETPGRP
@c @fuindex getpgrp
@prindex @code{getpgid}
@prindex @code{getpgrp}
+@caindex func_getpgrp_void
Define @code{GETPGRP_VOID} if it is an error to pass 0 to
@code{getpgrp}; this is the Posix behavior. On older @acronym{BSD}
systems, you must pass 0 to @code{getpgrp}, as it takes an argument and
@code{getpgrp} exists at all; if you need to work in that situation,
first call @code{AC_CHECK_FUNC} for @code{getpgrp}.
+The result of this macro is cached in the @code{ac_cv_func_getpgrp_void}
+variable.
+
This macro is obsolescent, as current systems have a @code{getpgrp}
whose signature conforms to Posix. New programs need not use this macro.
@end defmac
@cvindex LSTAT_FOLLOWS_SLASHED_SYMLINK
@c @fuindex lstat
@prindex @code{lstat}
+@caindex func_lstat_dereferences_slashed_symlink
If @file{link} is a symbolic link, then @code{lstat} should treat
@file{link/} the same as @file{link/.}. However, many older
@code{lstat} implementations incorrectly ignore trailing slashes.
If @code{lstat} behaves properly, define
@code{LSTAT_FOLLOWS_SLASHED_SYMLINK}, otherwise require an
@code{AC_LIBOBJ} replacement of @code{lstat}.
+
+The result of this macro is cached in the
+@code{ac_cv_func_lstat_dereferences_slashed_symlink} variable.
@end defmac
@defmac AC_FUNC_MALLOC
@cvindex malloc
@c @fuindex malloc
@prindex @code{malloc}
+@caindex func_malloc_0_nonnull
If the @code{malloc} function is compatible with the @acronym{GNU} C
library @code{malloc} (i.e., @samp{malloc (0)} returns a valid
pointer), define @code{HAVE_MALLOC} to 1. Otherwise define
return malloc (n);
}
@end verbatim
+
+The result of this macro is cached in the
+@code{ac_cv_func_malloc_0_nonnull} variable.
@end defmac
@defmac AC_FUNC_MEMCMP
@ovindex LIBOBJS
@c @fuindex memcmp
@prindex @code{memcmp}
+@caindex func_memcmp_working
If the @code{memcmp} function is not available, or does not work on
8-bit data (like the one on SunOS 4.1.3), or fails when comparing 16
bytes or more and with at least one buffer not starting on a 4-byte
boundary (such as the one on NeXT x86 OpenStep), require an
@code{AC_LIBOBJ} replacement for @samp{memcmp}.
+The result of this macro is cached in the
+@code{ac_cv_func_memcmp_working} variable.
+
This macro is obsolescent, as current systems have a working
@code{memcmp}. New programs need not use this macro.
@end defmac
@cvindex HAVE_MBRTOWC
@c @fuindex mbrtowc
@prindex @code{mbrtowc}
+@caindex func_mbrtowc
Define @code{HAVE_MBRTOWC} to 1 if the function @code{mbrtowc} and the
type @code{mbstate_t} are properly declared.
+
+The result of this macro is cached in the @code{ac_cv_func_mbrtowc}
+variable.
@end defmac
@defmac AC_FUNC_MKTIME
@ovindex LIBOBJS
@c @fuindex mktime
@prindex @code{mktime}
+@caindex func_working_mktime
If the @code{mktime} function is not available, or does not work
correctly, require an @code{AC_LIBOBJ} replacement for @samp{mktime}.
For the purposes of this test, @code{mktime} should conform to the
Posix standard and should be the inverse of
@code{localtime}.
+
+The result of this macro is cached in the
+@code{ac_cv_func_working_mktime} variable.
@end defmac
@anchor{AC_FUNC_MMAP}
@cvindex HAVE_MMAP
@c @fuindex mmap
@prindex @code{mmap}
+@caindex func_mmap_fixed_mapped
If the @code{mmap} function exists and works correctly, define
@code{HAVE_MMAP}. This checks only private fixed mapping of already-mapped
memory.
+
+The result of this macro is cached in the
+@code{ac_cv_func_mmap_fixed_mapped} variable.
@end defmac
@defmac AC_FUNC_OBSTACK
@acindex{FUNC_OBSTACK}
@cvindex HAVE_OBSTACK
@cindex obstack
+@caindex func_obstack
If the obstacks are found, define @code{HAVE_OBSTACK}, else require an
@code{AC_LIBOBJ} replacement for @samp{obstack}.
+
+The result of this macro is cached in the @code{ac_cv_func_obstack}
+variable.
@end defmac
@defmac AC_FUNC_REALLOC
@cvindex realloc
@c @fuindex realloc
@prindex @code{realloc}
+@caindex func_realloc_0_nonnull
If the @code{realloc} function is compatible with the @acronym{GNU} C
library @code{realloc} (i.e., @samp{realloc (NULL, 0)} returns a
valid pointer), define @code{HAVE_REALLOC} to 1. Otherwise define
@samp{realloc}, and define @code{realloc} to @code{rpl_realloc} so that
the native @code{realloc} is not used in the main project. See
@code{AC_FUNC_MALLOC} for details.
+
+The result of this macro is cached in the
+@code{ac_cv_func_realloc_0_nonnull} variable.
@end defmac
@defmac AC_FUNC_SELECT_ARGTYPES
@cvindex SELECT_TYPE_ARG5
@c @fuindex select
@prindex @code{select}
+@c @caindex func_select_args
Determines the correct type to be passed for each of the
@code{select} function's arguments, and defines those types
in @code{SELECT_TYPE_ARG1}, @code{SELECT_TYPE_ARG234}, and
@cvindex SETPGRP_VOID
@c @fuindex setpgrp
@prindex @code{setpgrp}
+@caindex func_setpgrp_void
If @code{setpgrp} takes no argument (the Posix version), define
@code{SETPGRP_VOID}. Otherwise, it is the @acronym{BSD} version, which takes
two process IDs as arguments. This macro does not check whether
@code{setpgrp} exists at all; if you need to work in that situation,
first call @code{AC_CHECK_FUNC} for @code{setpgrp}.
+The result of this macro is cached in the @code{ac_cv_func_setpgrp_void}
+variable.
+
This macro is obsolescent, as current systems have a @code{setpgrp}
whose signature conforms to Posix. New programs need not use this macro.
@end defmac
@prindex @code{stat}
@c @fuindex lstat
@prindex @code{lstat}
+@caindex func_stat_empty_string_bug
+@caindex func_lstat_empty_string_bug
Determine whether @code{stat} or @code{lstat} have the bug that it
succeeds when given the zero-length file name as argument. The @code{stat}
and @code{lstat} from SunOS 4.1.4 and the Hurd (as of 1998-11-01) do
@code{HAVE_LSTAT_EMPTY_STRING_BUG}) and ask for an @code{AC_LIBOBJ}
replacement of it.
+The results of these macros are cached in the
+@code{ac_cv_func_stat_empty_string_bug} and the
+@code{ac_cv_func_stat_empty_string_bug} variables, respectively.
+
These macros are obsolescent, as no current systems have the bug.
New programs need not use these macros.
@end defmac
@cvindex HAVE_STRCOLL
@c @fuindex strcoll
@prindex @code{strcoll}
+@caindex func_strcoll_works
If the @code{strcoll} function exists and works correctly, define
@code{HAVE_STRCOLL}. This does a bit more than
@samp{AC_CHECK_FUNCS(strcoll)}, because some systems have incorrect
definitions of @code{strcoll} that should not be used.
+
+The result of this macro is cached in the @code{ac_cv_func_strcoll_works}
+variable.
@end defmac
@defmac AC_FUNC_STRERROR_R
@cvindex HAVE_DECL_STRERROR_R
@cvindex STRERROR_R_CHAR_P
@c @fuindex strerror_r
+@caindex func_strerror_r_char_p
@prindex @code{strerror_r}
If @code{strerror_r} is available, define @code{HAVE_STRERROR_R}, and if
it is declared, define @code{HAVE_DECL_STRERROR_R}. If it returns a
many systems (including, for example, version 2.2.4 of the @acronym{GNU} C
Library) return a @code{char *} value that is not necessarily equal to
the buffer argument.
+
+The result of this macro is cached in the
+@code{ac_cv_func_strerror_r_char_p} variable.
@end defmac
@anchor{AC_FUNC_STRFTIME}
@ovindex POW_LIB
@c @fuindex strtod
@prindex @code{strtod}
+@caindex func_strtod
+@caindex func_pow
If the @code{strtod} function does not exist or doesn't work correctly,
ask for an @code{AC_LIBOBJ} replacement of @samp{strtod}. In this case,
because @file{strtod.c} is likely to need @samp{pow}, set the output
variable @code{POW_LIB} to the extra library needed.
+
+This macro caches its result in the @code{ac_cv_func_strtod} variable
+and depends upon the result in the @code{ac_cv_func_pow} variable.
@end defmac
@defmac AC_FUNC_STRTOLD
@acindex{FUNC_STRTOLD}
@cvindex HAVE_STRTOLD
@prindex @code{strtold}
+@caindex func_strtold
If the @code{strtold} function exists and conforms to C99, define
@code{HAVE_STRTOLD}.
+
+This macro caches its result in the @code{ac_cv_func_strtold} variable.
@end defmac
@defmac AC_FUNC_STRNLEN
@cvindex HAVE_STRNLEN
@c @fuindex strnlen
@prindex @code{strnlen}
+@caindex func_strnlen_working
If the @code{strnlen} function is not available, or is buggy (like the one
from @acronym{AIX} 4.3), require an @code{AC_LIBOBJ} replacement for it.
+
+This macro caches its result in the @code{ac_cv_func_strnlen_working}
+variable.
@end defmac
@anchor{AC_FUNC_UTIME_NULL}
@cvindex HAVE_UTIME_NULL
@c @fuindex utime
@prindex @code{utime}
+@caindex func_utime_null
If @samp{utime (@var{file}, NULL)} sets @var{file}'s timestamp to
the present, define @code{HAVE_UTIME_NULL}.
+This macro caches its result in the @code{ac_cv_func_utime_null}
+variable.
+
This macro is obsolescent, as all current systems have a @code{utime}
that behaves this way. New programs need not use this macro.
@end defmac
@c @fuindex fnmatch
@prindex @code{fnmatch}
@hdrindex{fnmatch.h}
+@caindex func_fnmatch_works
If the @code{fnmatch} function does not conform to Posix (see
@code{AC_FUNC_FNMATCH}), ask for its @code{AC_LIBOBJ} replacement.
@file{fnmatch_.h} file is linked to @file{fnmatch.h} so that it can be
included in place of the system @code{<fnmatch.h>}.
+This macro caches its result in the @code{ac_cv_func_fnmatch_works}
+variable.
+
This macro is obsolescent, as it assumes the use of particular source
files. New programs should use Gnulib's @code{fnmatch-posix} module,
which provides this macro along with the source files. @xref{Gnulib}.
@defmac AC_CHECK_FUNC (@var{function}, @ovar{action-if-found}, @
@ovar{action-if-not-found})
@acindex{CHECK_FUNC}
+@caindex func_@var{function}
If C function @var{function} is available, run shell commands
@var{action-if-found}, otherwise @var{action-if-not-found}. If you just
want to define a symbol if the function is available, consider using
linkage even when @code{AC_LANG(C++)} has been called, since C is more
standardized than C++. (@pxref{Language Choice}, for more information
about selecting the language for checks.)
+
+This macro caches its result in the @code{ac_cv_func_@var{function}}
+variable.
@end defmac
@anchor{AC_CHECK_FUNCS}
@samp{break} to break out of the loop on the first match. If
@var{action-if-not-found} is given, it is executed when one of the
functions is not found.
+
+Results are cached for each @var{function} as in @code{AC_CHECK_FUNC}.
@end defmac
@defmac AC_CHECK_FUNCS_ONCE (@var{function}@dots{})
@cvindex HAVE__BOOL
@hdrindex{stdbool.h}
@hdrindex{system.h}
+@caindex header_stdbool_h
If @file{stdbool.h} exists and conforms to C99, define
@code{HAVE_STDBOOL_H} to 1; if the type @code{_Bool} is defined, define
@code{HAVE__BOOL} to 1. To fulfill the C99 requirements, your
(@pxref{Gnulib}); it packages the above code into a replacement header
and contains a few other bells and whistles.
+This macro caches its result in the @code{ac_cv_header_stdbool_h}
+variable.
@end defmac
@anchor{AC_HEADER_STDC}
@hdrindex{string.h}
@hdrindex{float.h}
@hdrindex{ctype.h}
+@caindex header_stdc
Define @code{STDC_HEADERS} if the system has C header files
conforming to @acronym{ANSI} C89 (@acronym{ISO} C90).
Specifically, this macro checks for @file{stdlib.h}, @file{stdarg.h},
determine whether the system has conforming header files (and probably C
library functions).
+This macro caches its results in the @code{ac_cv_header_stdc} variable.
+
This macro is obsolescent, as current systems have conforming header
files. New programs need not use this macro.
@acindex{HEADER_SYS_WAIT}
@cvindex HAVE_SYS_WAIT_H
@hdrindex{sys/wait.h}
+@caindex header_sys_wait_h
If @file{sys/wait.h} exists and is compatible with Posix, define
@code{HAVE_SYS_WAIT_H}. Incompatibility can occur if @file{sys/wait.h}
does not exist, or if it uses the old @acronym{BSD} @code{union wait} instead
@end example
@noindent
+This macro caches its result in the @code{ac_cv_header_sys_wait_h}
+variable.
+
This macro is obsolescent, as current systems are compatible with Posix.
New programs need not use this macro.
@end defmac
@cvindex TIME_WITH_SYS_TIME
@hdrindex{time.h}
@hdrindex{sys/time.h}
+@caindex header_time
If a program may include both @file{time.h} and @file{sys/time.h},
define @code{TIME_WITH_SYS_TIME}. On some ancient systems,
@file{sys/time.h} included @file{time.h}, but @file{time.h} was not
@end example
@noindent
+This macro caches its result in the @code{ac_cv_header_time} variable.
+
This macro is obsolescent, as current systems can include both files
when they exist. New programs need not use this macro.
@end defmac
@defmac AC_CHECK_HEADER (@var{header-file}, @ovar{action-if-found}, @
@ovar{action-if-not-found}, @ovar{includes})
@acindex{CHECK_HEADER}
+@caindex header_@var{header-file}
If the system header file @var{header-file} is compilable, execute shell
commands @var{action-if-found}, otherwise execute
@var{action-if-not-found}. If you just want to define a symbol if the
a last resort (it is safer to determine the actual prerequisites and
perform a compiler check, or else use @code{AC_PREPROC_IFELSE} to make
it obvious that only a preprocessor check is desired).
+
+This macro caches its result in the @code{ac_cv_header_@var{header-file}}
+variable, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
@anchor{AC_CHECK_HEADERS}
@ovar{includes})
@acindex{CHECK_HEADERS}
@cvindex HAVE_@var{header}
+@caindex header_@var{header-file}
For each given system header file @var{header-file} in the
blank-separated argument list that exists, define
@code{HAVE_@var{header-file}} (in all capitals). If @var{action-if-found}
@var{includes} is interpreted as in @code{AC_CHECK_HEADER}, in order to
choose the set of preprocessor directives supplied before the header
under test.
+
+This macro caches its result in the @code{ac_cv_header_@var{header-file}}
+variable, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
Previous versions of Autoconf merely checked whether the header was
@defmac AC_CHECK_DECL (@var{symbol}, @ovar{action-if-found}, @
@ovar{action-if-not-found}, @dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_DECL}
+@caindex have_decl_@var{symbol}
If @var{symbol} (a function, variable, or constant) is not declared in
@var{includes} and a declaration is needed, run the shell commands
@var{action-if-not-found}, otherwise @var{action-if-found}.
can be used as an r-value, not whether it is really declared, because it
is much safer to avoid
introducing extra declarations when they are not needed.
+
+This macro caches its result in the @code{ac_cv_have_decl_@var{symbol}}
+variable, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
@anchor{AC_CHECK_DECLS}
@ovar{action-if-not-found}, @dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_DECLS}
@cvindex HAVE_DECL_@var{symbol}
+@caindex have_decl_@var{symbol}
For each of the @var{symbols} (@emph{comma}-separated list), define
@code{HAVE_DECL_@var{symbol}} (in all capitals) to @samp{1} if
@var{symbol} is declared, otherwise to @samp{0}. If
You fall into the second category only in extreme situations: either
your files may be used without being configured, or they are used during
the configuration. In most cases the traditional approach is enough.
+
+This macro caches its results in @code{ac_cv_have_decl_@var{symbol}}
+variables, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
@defmac AC_CHECK_DECLS_ONCE (@var{symbols})
@defmac AC_STRUCT_DIRENT_D_INO
@acindex{STRUCT_DIRENT_D_INO}
@cvindex HAVE_STRUCT_DIRENT_D_INO
+@c @caindex header_dirent_dirent_h
+@c @caindex member_struct_dirent_d_ino
Perform all the actions of @code{AC_HEADER_DIRENT} (@pxref{Particular
Headers}). Then, if @code{struct dirent} contains a @code{d_ino}
member, define @code{HAVE_STRUCT_DIRENT_D_INO}.
@defmac AC_STRUCT_DIRENT_D_TYPE
@acindex{STRUCT_DIRENT_D_TYPE}
@cvindex HAVE_STRUCT_DIRENT_D_TYPE
+@c @caindex header_dirent_dirent_h
+@c @caindex member_struct_dirent_d_type
Perform all the actions of @code{AC_HEADER_DIRENT} (@pxref{Particular
Headers}). Then, if @code{struct dirent} contains a @code{d_type}
member, define @code{HAVE_STRUCT_DIRENT_D_TYPE}.
@cvindex HAVE_STRUCT_STAT_ST_BLOCKS
@cvindex HAVE_ST_BLOCKS
@ovindex LIBOBJS
+@caindex member_struct_stat_st_blocks
If @code{struct stat} contains an @code{st_blocks} member, define
@code{HAVE_STRUCT_STAT_ST_BLOCKS}. Otherwise, require an
@code{AC_LIBOBJ} replacement of @samp{fileblocks}. The former name,
@code{HAVE_ST_BLOCKS} is to be avoided, as its support will cease in the
future.
+
+This macro caches its result in the @code{ac_cv_member_struct_stat_st_blocks}
+variable.
@end defmac
@defmac AC_STRUCT_TM
@cvindex HAVE_STRUCT_TM_TM_ZONE
@cvindex HAVE_TM_ZONE
@cvindex HAVE_TZNAME
+@c @caindex member_struct_tm_tm_zone
+@c @caindex struct_tm
Figure out how to get the current timezone. If @code{struct tm} has a
@code{tm_zone} member, define @code{HAVE_STRUCT_TM_TM_ZONE} (and the
obsoleted @code{HAVE_TM_ZONE}). Otherwise, if the external array
@ovar{action-if-found}, @ovar{action-if-not-found}, @
@dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_MEMBER}
+@caindex member_@var{aggregate}_@var{member}
Check whether @var{member} is a member of the aggregate @var{aggregate}.
If no @var{includes} are specified, the default includes are used
(@pxref{Default Includes}).
@example
AC_CHECK_MEMBER(struct top.middle.bot)
@end example
+
+This macro caches its result in the
+@code{av_cv_member_@var{aggregate}_@var{member}} variable, with
+characters not suitable for a variable name mapped to underscores.
@end defmac
@anchor{AC_CHECK_MEMBERS}
@defmac AC_TYPE_GETGROUPS
@acindex{TYPE_GETGROUPS}
@cvindex GETGROUPS_T
+@caindex type_getgroups
Define @code{GETGROUPS_T} to be whichever of @code{gid_t} or @code{int}
is the base type of the array argument to @code{getgroups}.
+
+This macro caches the base type in the @code{ac_cv_type_getgroups}
+variable.
@end defmac
@defmac AC_TYPE_INT8_T
@acindex{TYPE_INT8_T}
@cvindex HAVE_INT8_T
@cvindex int8_t
+@caindex c_int8_t
If @file{stdint.h} or @file{inttypes.h} does not define the type
@code{int8_t}, define @code{int8_t} to a signed
integer type that is exactly 8 bits wide and that uses two's complement
@emph{complicated alternative using >8-bit 'signed char'}
#endif
@end example
+
+This macro caches the type in the @code{ac_cv_c_int8_t} variable.
@end defmac
@defmac AC_TYPE_INT16_T
@acindex{TYPE_INT16_T}
@cvindex HAVE_INT16_T
@cvindex int16_t
+@caindex c_int16_t
This is like @code{AC_TYPE_INT8_T}, except for 16-bit integers.
@end defmac
@acindex{TYPE_INT32_T}
@cvindex HAVE_INT32_T
@cvindex int32_t
+@caindex c_int32_t
This is like @code{AC_TYPE_INT8_T}, except for 32-bit integers.
@end defmac
@acindex{TYPE_INT64_T}
@cvindex HAVE_INT64_T
@cvindex int64_t
+@caindex c_int64_t
This is like @code{AC_TYPE_INT8_T}, except for 64-bit integers.
@end defmac
@acindex{TYPE_INTMAX_T}
@cvindex HAVE_INTMAX_T
@cvindex intmax_t
+@c @caindex type_intmax_t
If @file{stdint.h} or @file{inttypes.h} defines the type @code{intmax_t},
define @code{HAVE_INTMAX_T}. Otherwise, define @code{intmax_t} to the
widest signed integer type.
@acindex{TYPE_INTPTR_T}
@cvindex HAVE_INTPTR_T
@cvindex intptr_t
+@c @caindex type_intptr_t
If @file{stdint.h} or @file{inttypes.h} defines the type @code{intptr_t},
define @code{HAVE_INTPTR_T}. Otherwise, define @code{intptr_t} to a
signed integer type wide enough to hold a pointer, if such a type
@defmac AC_TYPE_LONG_DOUBLE
@acindex{TYPE_LONG_DOUBLE}
@cvindex HAVE_LONG_DOUBLE
+@caindex type_long_double
If the C compiler supports a working @code{long double} type, define
@code{HAVE_LONG_DOUBLE}. The @code{long double} type might have the
same range and precision as @code{double}.
+This macro caches its result in the @code{ac_cv_type_long_double}
+variable.
+
This macro is obsolescent, as current C compilers support @code{long
double}. New programs need not use this macro.
@end defmac
@defmac AC_TYPE_LONG_DOUBLE_WIDER
@acindex{TYPE_LONG_DOUBLE_WIDER}
@cvindex HAVE_LONG_DOUBLE_WIDER
+@caindex type_long_double_wider
If the C compiler supports a working @code{long double} type with more
range or precision than the @code{double} type, define
@code{HAVE_LONG_DOUBLE_WIDER}.
+
+This macro caches its result in the @code{ac_cv_type_long_double_wider}
+variable.
@end defmac
@defmac AC_TYPE_LONG_LONG_INT
@acindex{TYPE_LONG_LONG_INT}
@cvindex HAVE_LONG_LONG_INT
+@caindex type_long_long_int
If the C compiler supports a working @code{long long int} type, define
@code{HAVE_LONG_LONG_INT}. However, this test does not test
@code{long long int} values in preprocessor @code{#if} expressions,
because too many compilers mishandle such expressions.
@xref{Preprocessor Arithmetic}.
+
+This macro caches its result in the @code{ac_cv_type_long_long_int}
+variable.
@end defmac
@defmac AC_TYPE_MBSTATE_T
@acindex{TYPE_MBSTATE_T}
@cvindex mbstate_t
@hdrindex{wchar.h}
+@caindex type_mbstate_t
Define @code{HAVE_MBSTATE_T} if @code{<wchar.h>} declares the
@code{mbstate_t} type. Also, define @code{mbstate_t} to be a type if
@code{<wchar.h>} does not declare it.
+
+This macro caches its result in the @code{ac_cv_type_mbstate_t}
+variable.
@end defmac
@anchor{AC_TYPE_MODE_T}
@defmac AC_TYPE_MODE_T
@acindex{TYPE_MODE_T}
@cvindex mode_t
+@caindex type_mode_t
Define @code{mode_t} to a suitable type, if standard headers do not
define it.
+
+This macro caches its result in the @code{ac_cv_type_mode_t} variable.
@end defmac
@anchor{AC_TYPE_OFF_T}
@defmac AC_TYPE_OFF_T
@acindex{TYPE_OFF_T}
@cvindex off_t
+@caindex type_off_t
Define @code{off_t} to a suitable type, if standard headers do not
define it.
+
+This macro caches its result in the @code{ac_cv_type_off_t} variable.
@end defmac
@anchor{AC_TYPE_PID_T}
@defmac AC_TYPE_PID_T
@acindex{TYPE_PID_T}
@cvindex pid_t
+@caindex type_pid_t
Define @code{pid_t} to a suitable type, if standard headers do not
define it.
+
+This macro caches its result in the @code{ac_cv_type_pid_t} variable.
@end defmac
@anchor{AC_TYPE_SIZE_T}
@defmac AC_TYPE_SIZE_T
@acindex{TYPE_SIZE_T}
@cvindex size_t
+@caindex type_size_t
Define @code{size_t} to a suitable type, if standard headers do not
define it.
+
+This macro caches its result in the @code{ac_cv_type_size_t} variable.
@end defmac
@defmac AC_TYPE_SSIZE_T
@acindex{TYPE_SSIZE_T}
@cvindex ssize_t
+@caindex type_ssize_t
Define @code{ssize_t} to a suitable type, if standard headers do not
define it.
+
+This macro caches its result in the @code{ac_cv_type_ssize_t} variable.
@end defmac
@anchor{AC_TYPE_UID_T}
@acindex{TYPE_UID_T}
@cvindex uid_t
@cvindex gid_t
+@caindex type_uid_t
Define @code{uid_t} and @code{gid_t} to suitable types, if standard
headers do not define them.
+
+This macro caches its result in the @code{ac_cv_type_uid_t} variable.
@end defmac
@defmac AC_TYPE_UINT8_T
@acindex{TYPE_UINT8_T}
@cvindex HAVE_UINT8_T
@cvindex uint8_t
+@caindex c_uint8_t
If @file{stdint.h} or @file{inttypes.h} does not define the type
@code{uint8_t}, define @code{uint8_t} to an
unsigned integer type that is exactly 8 bits wide, if such a type
@acindex{TYPE_UINT16_T}
@cvindex HAVE_UINT16_T
@cvindex uint16_t
+@caindex c_uint16_t
This is like @code{AC_TYPE_UINT8_T}, except for 16-bit integers.
@end defmac
@acindex{TYPE_UINT32_T}
@cvindex HAVE_UINT32_T
@cvindex uint32_t
+@caindex c_uint32_t
This is like @code{AC_TYPE_UINT8_T}, except for 32-bit integers.
@end defmac
@acindex{TYPE_UINT64_T}
@cvindex HAVE_UINT64_T
@cvindex uint64_t
+@caindex c_uint64_t
This is like @code{AC_TYPE_UINT8_T}, except for 64-bit integers.
@end defmac
@acindex{TYPE_UINTMAX_T}
@cvindex HAVE_UINTMAX_T
@cvindex uintmax_t
+@c @caindex type_uintmax_t
If @file{stdint.h} or @file{inttypes.h} defines the type @code{uintmax_t},
define @code{HAVE_UINTMAX_T}. Otherwise, define @code{uintmax_t} to the
widest unsigned integer type.
@acindex{TYPE_UINTPTR_T}
@cvindex HAVE_UINTPTR_T
@cvindex uintptr_t
+@c @caindex type_uintptr_t
If @file{stdint.h} or @file{inttypes.h} defines the type @code{uintptr_t},
define @code{HAVE_UINTPTR_T}. Otherwise, define @code{uintptr_t} to an
unsigned integer type wide enough to hold a pointer, if such a type
@defmac AC_TYPE_UNSIGNED_LONG_LONG_INT
@acindex{TYPE_UNSIGNED_LONG_LONG_INT}
@cvindex HAVE_UNSIGNED_LONG_LONG_INT
+@caindex type_unsigned_long_long_int
If the C compiler supports a working @code{unsigned long long int} type,
define @code{HAVE_UNSIGNED_LONG_LONG_INT}. However, this test does not test
@code{unsigned long long int} values in preprocessor @code{#if} expressions,
because too many compilers mishandle such expressions.
@xref{Preprocessor Arithmetic}.
+
+This macro caches its result in the @code{ac_cv_type_unsigned_long_long_int}
+variable.
@end defmac
@node Generic Types
@defmac AC_CHECK_TYPE (@var{type}, @ovar{action-if-found}, @
@ovar{action-if-not-found}, @dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_TYPE}
+@caindex type_@var{type}
Check whether @var{type} is defined. It may be a compiler builtin type
or defined by the @var{includes}. @var{includes} is a series of include
directives, defaulting to @code{AC_INCLUDES_DEFAULT} (@pxref{Default
same test is applied when compiling for C++, which means that in C++
@var{type} should be a type-id and should not be an anonymous
@samp{struct} or @samp{union}.
+
+This macro caches its result in the @code{ac_cv_type_@var{type}}
+variable, with @samp{*} mapped to @samp{p} and other characters not
+suitable for a variable name mapped to underscores.
@end defmac
@dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_SIZEOF}
@cvindex SIZEOF_@var{type-or-expr}
+@caindex sizeof_@var{type-or-expr}
Define @code{SIZEOF_@var{type-or-expr}} (@pxref{Standard Symbols}) to be
the size in bytes of @var{type-or-expr}, which may be either a type or
an expression returning a value that has a size. If the expression
@noindent
defines @code{SIZEOF_INT_P} to be 8 on DEC Alpha AXP systems.
+
+This macro caches its result in the @code{ac_cv_sizeof_@var{type-or-expr}}
+variable, with @samp{*} mapped to @samp{p} and other characters not
+suitable for a variable name mapped to underscores.
@end defmac
@defmac AC_CHECK_ALIGNOF (@var{type}, @dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_ALIGNOF}
@cvindex ALIGNOF_@var{type}
+@caindex alignof_@var{type-or-expr}
Define @code{ALIGNOF_@var{type}} (@pxref{Standard Symbols}) to be the
alignment in bytes of @var{type}. @samp{@var{type} y;} must be valid as
a structure member declaration. If @samp{type} is unknown, the result
is 0. If no @var{includes} are specified, the default includes are used
(@pxref{Default Includes}).
+
+This macro caches its result in the @code{ac_cv_alignof_@var{type-or-expr}}
+variable, with @samp{*} mapped to @samp{p} and other characters not
+suitable for a variable name mapped to underscores.
@end defmac
@defmac AC_COMPUTE_INT (@var{var}, @var{expression}, @
@evindex CFLAGS
@ovindex CC
@ovindex CFLAGS
+@caindex prog_cc_c89
Determine a C compiler to use. If @code{CC} is not already set in the
environment, check for @code{gcc} and @code{cc}, then for other C
compilers. Set output variable @code{CC} to the name of the compiler
@defmac AC_PROG_CC_C_O
@acindex{PROG_CC_C_O}
@cvindex NO_MINUS_C_MINUS_O
+@caindex prog_cc_@var{compiler}_c_o
If the C compiler does not accept the @option{-c} and @option{-o} options
simultaneously, define @code{NO_MINUS_C_MINUS_O}. This macro actually
tests both the compiler found by @code{AC_PROG_CC}, and, if different,
the first @code{cc} in the path. The test fails if one fails. This
macro was created for @acronym{GNU} Make to choose the default C compilation
rule.
+
+For the compiler @var{compiler}, this macro caches its result in the
+@code{ac_cv_prog_cc_@var{compiler}_c_o} variable.
@end defmac
@defmac AC_PROG_CC_STDC
@acindex{PROG_CC_STDC}
+@caindex prog_cc_stdc
If the C compiler cannot compile @acronym{ISO} Standard C (currently
C99), try to add an option to output variable @code{CC} to make it work.
If the compiler does not support C99, fall back to supporting
@defmac AC_PROG_CC_C89
@acindex{PROG_CC_C89}
+@caindex prog_cc_c89
If the C compiler is not in @acronym{ANSI} C89 (@acronym{ISO} C90) mode by
default, try to add an option to output variable @code{CC} to make it
so. This macro tries various options that select @acronym{ANSI} C89 on
@defmac AC_PROG_CC_C99
@acindex{PROG_CC_C99}
+@caindex prog_cc_c99
If the C compiler is not in C99 mode by default, try to add an
option to output variable @code{CC} to make it so. This macro tries
various options that select C99 on some system or another, preferring
@defmac AC_C_CONST
@acindex{C_CONST}
@cvindex const
+@caindex c_const
If the C compiler does not fully support the @code{const} keyword,
define @code{const} to be empty. Some C compilers that do
not define @code{__STDC__} do support @code{const}; some compilers that
installers who run into trouble in this area should get a C compiler
like @acronym{GCC} to compile their C code.
+This macro caches its result in the @code{ac_cv_c_const} variable.
+
This macro is obsolescent, as current C compilers support @code{const}.
New programs need not use this macro.
@end defmac
@defmac AC_C_RESTRICT
@acindex{C_RESTRICT}
@cvindex restrict
+@caindex c_restrict
If the C compiler recognizes a variant spelling for the @code{restrict}
keyword (@code{__restrict}, @code{__restrict__}, or @code{_Restrict}),
then define @code{restrict} to that; this is more likely to do the right
Although support in C++ for the @code{restrict} keyword is not
required, several C++ compilers do accept the keyword.
This macro works for them, too.
+
+This macro caches @samp{no} in the @code{ac_cv_c_restrict} variable
+if @code{restrict} is not supported, and a supported spelling otherwise.
@end defmac
@defmac AC_C_VOLATILE
@acindex{SYS_POSIX_TERMIOS}
@cindex Posix termios headers
@cindex termios Posix headers
+@caindex sys_posix_termios
Check to see if the Posix termios headers and functions are available on the
system. If so, set the shell variable @code{ac_cv_sys_posix_termios} to
@samp{yes}. If not, set the variable to @samp{no}.
projects / thirdparty / autoconf.git / commitdiff
