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[PATCH 4/5] Documentation of specific and general cache variables.
|
From: |
Ralf Wildenhues |
|
Subject: |
[PATCH 4/5] Documentation of specific and general cache variables. |
|
Date: |
Sun, 13 Sep 2009 10:36:16 +0200 |
|
User-agent: |
Mutt/1.5.20 (2009-08-09) |
* doc/autoconf.texi (Default Includes, Alternative Programs)
(Particular Programs, Generic Programs, Files, Libraries)
(Function Portability, Particular Functions, Generic Functions)
(Particular Headers, Generic Headers, Declarations)
(Generic Declarations, Particular Structures, Particular Types)
(Specific Compiler Characteristics)
(Generic Compiler Characteristics, C Compiler, System Services):
Document lots of cache variables.
* NEWS: Update.
Suggested by Bruno Haible.
---
Here is a list of macros that are listed in the non-obsolete part of
the manual but whose cache variables I have not documented, including
rationale:
1) Complex semantics and/or contents of the cache variables:
AC_*TOOL*
AC_FUNC_SELECT_ARGTYPES
AC_HEADER_MAJOR
AC_HEADER_RESOLV
AC_HEADER_TIOCGWINSZ
AC_PROG_CPP
AC_C_BIGENDIAN
AC_STRUCT_DIRENT_D_INO
AC_STRUCT_TIMEZONE
AC_TYPE_INTMAX_T
AC_TYPE_UINTMAX_T
2) It's likely that the test might (need to) evolve further (we might
find new bugs in systems or similar), requiring changes in cache
variabls semantics:
AC_FUNC_MMAP
AC_OPENMP
3) Obsolescence:
AC_FUNC_STRFTIME
AC_C_BACKSLASH_A
AC_STRUCT_TM
some more (most of the obsolete ones)
4) Both (1) and (2):
AC_FUNC_VPRITNF
AC_HEADER_DIRENT
AS_HEADER_STAT
AC_C_LONG_DOUBLE
5) Complex semantics; also, on some systems these macros requires a
compile test even with a fully populated cache (which defeats at least
one purpose of cache variables: overriding a bogus test result):
AC_TYPE_INTPTR_T
AC_TYPE_UINTPTR_T
6) AC_PROG_LN_S has no cache override; this used to be different, and
in fact can be a problem on lesser common systems like DJGPP.
Cheers,
Ralf
NEWS | 2 +
doc/autoconf.texi | 318 +++++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 310 insertions(+), 10 deletions(-)
diff --git a/NEWS b/NEWS
index 262be0c..3fdea30 100644
--- a/NEWS
+++ b/NEWS
@@ -26,6 +26,8 @@ GNU Autoconf NEWS - User visible changes.
** config.status now provides a --config option to produce the configuration.
+** Many cache variables used by Autoconf's macros are documented now.
+
* Major changes in Autoconf 2.64 (2009-07-26) [stable]
Released by Eric Blake, based on git versions 2.63b.*.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 0b0cbee..9206475 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -3859,36 +3859,44 @@ Particular Programs
@defmac AC_PROG_AWK
@acindex{PROG_AWK}
@ovindex AWK
address@hidden 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
address@hidden 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
address@hidden prog_EGREP
Check whether @code{$GREP -E} works, or else look for the best available
@code{egrep} or @code{gegrep} that accepts the longest input lines possible.
-Set the output variable @code{EGREP} to whatever is chosen.
+Set the output variable @code{EGREP} to whatever is chosen. The result
+is cached in the @code{ac_cv_path_EGREP} variable.
@end defmac
@defmac AC_PROG_FGREP
@acindex{PROG_FGREP}
@ovindex FGREP
address@hidden prog_FGREP
Check whether @code{$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
@@ -3897,6 +3905,7 @@ Particular Programs
@ovindex INSTALL_PROGRAM
@ovindex INSTALL_DATA
@ovindex INSTALL_SCRIPT
address@hidden 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 @address@hidden/install-sh -c},
@@ -3929,11 +3938,15 @@ Particular Programs
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
address@hidden 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
@@ -3964,6 +3977,9 @@ Particular Programs
@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}
@@ -3973,6 +3989,7 @@ Particular Programs
@ovindex LEXLIB
@cvindex YYTEXT_POINTER
@ovindex LEX_OUTPUT_ROOT
address@hidden 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
@@ -4022,6 +4039,8 @@ Particular Programs
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}
@@ -4054,6 +4073,8 @@ Particular Programs
@defmac AC_PROG_RANLIB
@acindex{PROG_RANLIB}
@ovindex RANLIB
address@hidden @caindex prog_RANLIB
address@hidden @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
@@ -4061,10 +4082,13 @@ Particular Programs
@defmac AC_PROG_SED
@acindex{PROG_SED}
@ovindex SED
address@hidden 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
@@ -4072,9 +4096,11 @@ Particular Programs
@evindex YACC
@evindex YFLAGS
@ovindex YACC
address@hidden 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
@@ -4103,6 +4129,7 @@ Generic Programs
@var{value-if-found}, @ovar{value-if-not-found}, @dvar{path, $PATH}, @
@ovar{reject})
@acindex{CHECK_PROG}
address@hidden address@hidden
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
@@ -4110,20 +4137,23 @@ Generic Programs
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
address@hidden
address@hidden The result of this test is cached in the
address@hidden@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}
address@hidden address@hidden
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 @address@hidden variable.
@end defmac
@defmac AC_CHECK_TARGET_TOOL (@var{variable}, @var{prog-to-check-for}, @
@@ -4147,6 +4177,8 @@ Generic Programs
@defmac AC_CHECK_TOOL (@var{variable}, @var{prog-to-check-for}, @
@ovar{value-if-not-found}, @dvar{path, $PATH})
@acindex{CHECK_TOOL}
address@hidden @caindex address@hidden
address@hidden @caindex address@hidden
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
@@ -4201,14 +4233,17 @@ Generic Programs
@defmac AC_PATH_PROG (@var{variable}, @var{prog-to-check-for}, @
@ovar{value-if-not-found}, @dvar{path, $PATH})
@acindex{PATH_PROG}
address@hidden address@hidden
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 @address@hidden 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}
address@hidden address@hidden
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.
@@ -4218,6 +4253,7 @@ Generic Programs
@var{progs-to-check-for}, @var{feature-test}, @
@ovar{action-if-not-found}, @dvar{path, $PATH})
@acindex{PATH_PROGS_FEATURE_CHECK}
address@hidden address@hidden
This macro was introduced in Autoconf 2.62. If @var{variable} is not
empty, then set the cache variable @address@hidden to
its value. Otherwise, check for each program in the blank-separated
@@ -4288,17 +4324,23 @@ Files
@defmac AC_CHECK_FILE (@var{file}, @ovar{action-if-found}, @
@ovar{action-if-not-found})
@acindex{CHECK_FILE}
address@hidden address@hidden
Check whether file @var{file} exists on the native system. If it is
found, execute @var{action-if-found}, otherwise do
address@hidden, if given.
address@hidden, if given. The result of this test is cached
+in the @address@hidden 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}
address@hidden address@hidden
Executes @code{AC_CHECK_FILE} once for each file listed in @var{files}.
Additionally, defines @address@hidden (@pxref{Standard Symbols})
-for each file found.
+for each file found. The results of each test are cached in the
address@hidden@var{file}} variable, with characters not suitable for
+a variable name mapped to underscores.
@end defmac
@@ -4313,6 +4355,7 @@ Libraries
@defmac AC_CHECK_LIB (@var{library}, @var{function}, @
@ovar{action-if-found}, @ovar{action-if-not-found}, @ovar{other-libraries})
@acindex{CHECK_LIB}
address@hidden address@hidden@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.
@@ -4348,12 +4391,16 @@ Libraries
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
address@hidden@address@hidden 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}
address@hidden address@hidden
Search for a library defining @var{function} if it's not already
available. This equates to calling
@samp{AC_LINK_IFELSE([AC_LANG_CALL([], address@hidden)])} first with
@@ -4369,6 +4416,11 @@ Libraries
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
address@hidden@var{function}} variable as @samp{no}, if no library
+containing @var{function} was found, otherwise as the
address@hidden@var{library}} option that needs to be added to @code{LIBS}.
@end defmac
@@ -4668,6 +4720,7 @@ Particular Functions
@c @fuindex alloca
@prindex @code{alloca}
@hdrindex{alloca.h}
address@hidden 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},
@@ -4714,6 +4767,9 @@ Particular Functions
#endif
@end group
@end example
+
+The result of this macro is cached in the @code{ac_cv_working_alloca_h}
+variable.
@end defmac
@defmac AC_FUNC_CHOWN
@@ -4721,9 +4777,11 @@ Particular Functions
@cvindex HAVE_CHOWN
@c @fuindex chown
@prindex @code{chown}
address@hidden 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
address@hidden
address@hidden The result of this macro is cached in the
address@hidden variable.
@end defmac
@anchor{AC_FUNC_CLOSEDIR_VOID}
@@ -4732,6 +4790,7 @@ Particular Functions
@cvindex CLOSEDIR_VOID
@c @fuindex closedir
@prindex @code{closedir}
address@hidden 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.
@@ -4740,6 +4799,9 @@ Particular Functions
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
@@ -4748,14 +4810,19 @@ Particular Functions
@acindex{FUNC_ERROR_AT_LINE}
@c @fuindex error_at_line
@prindex @code{error_at_line}
address@hidden 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}
address@hidden 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.
@@ -4765,6 +4832,9 @@ Particular Functions
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
@@ -4773,11 +4843,15 @@ Particular Functions
@acindex{FUNC_FNMATCH_GNU}
@c @fuindex fnmatch
@prindex @code{fnmatch}
address@hidden 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
@@ -4794,6 +4868,8 @@ Particular Functions
@c @fuindex vfork
@prindex @code{vfork}
@hdrindex{vfork.h}
address@hidden @caindex func_fork
address@hidden @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.
@@ -4828,6 +4904,7 @@ Particular Functions
@prindex @code{fseeko}
@c @fuindex ftello
@prindex @code{ftello}
address@hidden @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
@@ -4842,6 +4919,7 @@ Particular Functions
@ovindex GETGROUPS_LIBS
@c @fuindex getgroups
@prindex @code{getgroups}
address@hidden 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
@@ -4915,10 +4993,14 @@ Particular Functions
@cvindex HAVE_GETMNTENT
@c @fuindex getmntent
@prindex @code{getmntent}
address@hidden 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
@@ -4928,6 +5010,7 @@ Particular Functions
@c @fuindex getpgrp
@prindex @code{getpgid}
@prindex @code{getpgrp}
address@hidden 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
@@ -4945,6 +5028,9 @@ Particular Functions
@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
@@ -4954,6 +5040,7 @@ Particular Functions
@cvindex LSTAT_FOLLOWS_SLASHED_SYMLINK
@c @fuindex lstat
@prindex @code{lstat}
address@hidden 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.
@@ -4965,6 +5052,9 @@ Particular Functions
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
address@hidden variable.
@end defmac
@defmac AC_FUNC_MALLOC
@@ -4973,6 +5063,7 @@ Particular Functions
@cvindex malloc
@c @fuindex malloc
@prindex @code{malloc}
address@hidden 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
@@ -5002,6 +5093,9 @@ Particular Functions
return malloc (n);
}
@end verbatim
+
+The result of this macro is cached in the
address@hidden variable.
@end defmac
@defmac AC_FUNC_MEMCMP
@@ -5009,12 +5103,16 @@ Particular Functions
@ovindex LIBOBJS
@c @fuindex memcmp
@prindex @code{memcmp}
address@hidden 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
address@hidden variable.
+
This macro is obsolescent, as current systems have a working
@code{memcmp}. New programs need not use this macro.
@end defmac
@@ -5024,8 +5122,12 @@ Particular Functions
@cvindex HAVE_MBRTOWC
@c @fuindex mbrtowc
@prindex @code{mbrtowc}
address@hidden 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
@@ -5033,11 +5135,15 @@ Particular Functions
@ovindex LIBOBJS
@c @fuindex mktime
@prindex @code{mktime}
address@hidden 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
address@hidden variable.
@end defmac
@anchor{AC_FUNC_MMAP}
@@ -5046,17 +5152,25 @@ Particular Functions
@cvindex HAVE_MMAP
@c @fuindex mmap
@prindex @code{mmap}
address@hidden 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
address@hidden variable.
@end defmac
@defmac AC_FUNC_OBSTACK
@acindex{FUNC_OBSTACK}
@cvindex HAVE_OBSTACK
@cindex obstack
address@hidden 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
@@ -5065,6 +5179,7 @@ Particular Functions
@cvindex realloc
@c @fuindex realloc
@prindex @code{realloc}
address@hidden 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
@@ -5072,6 +5187,9 @@ Particular Functions
@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
address@hidden variable.
@end defmac
@defmac AC_FUNC_SELECT_ARGTYPES
@@ -5081,6 +5199,7 @@ Particular Functions
@cvindex SELECT_TYPE_ARG5
@c @fuindex select
@prindex @code{select}
address@hidden @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
@@ -5097,12 +5216,16 @@ Particular Functions
@cvindex SETPGRP_VOID
@c @fuindex setpgrp
@prindex @code{setpgrp}
address@hidden 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
@@ -5117,6 +5240,8 @@ Particular Functions
@prindex @code{stat}
@c @fuindex lstat
@prindex @code{lstat}
address@hidden func_stat_empty_string_bug
address@hidden 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
@@ -5126,6 +5251,10 @@ Particular Functions
@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
address@hidden and the
address@hidden variables, respectively.
+
These macros are obsolescent, as no current systems have the bug.
New programs need not use these macros.
@end defmac
@@ -5136,10 +5265,14 @@ Particular Functions
@cvindex HAVE_STRCOLL
@c @fuindex strcoll
@prindex @code{strcoll}
address@hidden 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
@@ -5148,6 +5281,7 @@ Particular Functions
@cvindex HAVE_DECL_STRERROR_R
@cvindex STRERROR_R_CHAR_P
@c @fuindex strerror_r
address@hidden 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
@@ -5157,6 +5291,9 @@ Particular Functions
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
address@hidden variable.
@end defmac
@anchor{AC_FUNC_STRFTIME}
@@ -5177,18 +5314,26 @@ Particular Functions
@ovindex POW_LIB
@c @fuindex strtod
@prindex @code{strtod}
address@hidden func_strtod
address@hidden 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}
address@hidden 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
@@ -5196,8 +5341,12 @@ Particular Functions
@cvindex HAVE_STRNLEN
@c @fuindex strnlen
@prindex @code{strnlen}
address@hidden 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}
@@ -5206,9 +5355,13 @@ Particular Functions
@cvindex HAVE_UTIME_NULL
@c @fuindex utime
@prindex @code{utime}
address@hidden 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
@@ -5236,6 +5389,7 @@ Particular Functions
@c @fuindex fnmatch
@prindex @code{fnmatch}
@hdrindex{fnmatch.h}
address@hidden 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.
@@ -5246,6 +5400,9 @@ Particular Functions
@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}.
@@ -5267,6 +5424,7 @@ Generic Functions
@defmac AC_CHECK_FUNC (@var{function}, @ovar{action-if-found}, @
@ovar{action-if-not-found})
@acindex{CHECK_FUNC}
address@hidden address@hidden
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
@@ -5274,6 +5432,9 @@ Generic Functions
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 @address@hidden
+variable.
@end defmac
@anchor{AC_CHECK_FUNCS}
@@ -5288,6 +5449,8 @@ Generic Functions
@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 (@address@hidden)
@@ -5665,6 +5828,7 @@ Particular Headers
@cvindex HAVE__BOOL
@hdrindex{stdbool.h}
@hdrindex{system.h}
address@hidden 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
@@ -5692,6 +5856,8 @@ Particular Headers
(@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}
@@ -5703,6 +5869,7 @@ Particular Headers
@hdrindex{string.h}
@hdrindex{float.h}
@hdrindex{ctype.h}
address@hidden 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},
@@ -5718,6 +5885,8 @@ Particular Headers
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.
@@ -5786,6 +5955,7 @@ Particular Headers
@acindex{HEADER_SYS_WAIT}
@cvindex HAVE_SYS_WAIT_H
@hdrindex{sys/wait.h}
address@hidden 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
@@ -5810,6 +5980,9 @@ Particular Headers
@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
@@ -5842,6 +6015,7 @@ Particular Headers
@cvindex TIME_WITH_SYS_TIME
@hdrindex{time.h}
@hdrindex{sys/time.h}
address@hidden 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
@@ -5868,6 +6042,8 @@ Particular Headers
@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
@@ -5910,6 +6086,7 @@ Generic Headers
@defmac AC_CHECK_HEADER (@var{header-file}, @ovar{action-if-found}, @
@ovar{action-if-not-found}, @ovar{includes})
@acindex{CHECK_HEADER}
address@hidden address@hidden
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
@@ -5936,6 +6113,10 @@ Generic Headers
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 @address@hidden
+variable, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
@anchor{AC_CHECK_HEADERS}
@@ -5944,6 +6125,7 @@ Generic Headers
@ovar{includes})
@acindex{CHECK_HEADERS}
@cvindex address@hidden
address@hidden address@hidden
For each given system header file @var{header-file} in the
blank-separated argument list that exists, define
@address@hidden (in all capitals). If @var{action-if-found}
@@ -5955,6 +6137,10 @@ Generic Headers
@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 @address@hidden
+variable, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
Previous versions of Autoconf merely checked whether the header was
@@ -6028,6 +6214,7 @@ Generic Declarations
@defmac AC_CHECK_DECL (@var{symbol}, @ovar{action-if-found}, @
@ovar{action-if-not-found}, @dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_DECL}
address@hidden address@hidden
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}.
@@ -6039,6 +6226,10 @@ Generic Declarations
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 @address@hidden
+variable, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
@anchor{AC_CHECK_DECLS}
@@ -6046,6 +6237,7 @@ Generic Declarations
@ovar{action-if-not-found}, @dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_DECLS}
@cvindex address@hidden
address@hidden address@hidden
For each of the @var{symbols} (@emph{comma}-separated list), define
@address@hidden (in all capitals) to @samp{1} if
@var{symbol} is declared, otherwise to @samp{0}. If
@@ -6092,6 +6284,10 @@ Generic Declarations
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 @address@hidden
+variables, with characters not suitable for a variable name mapped to
+underscores.
@end defmac
@defmac AC_CHECK_DECLS_ONCE (@var{symbols})
@@ -6130,6 +6326,8 @@ Particular Structures
@defmac AC_STRUCT_DIRENT_D_INO
@acindex{STRUCT_DIRENT_D_INO}
@cvindex HAVE_STRUCT_DIRENT_D_INO
address@hidden @caindex header_dirent_dirent_h
address@hidden @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}.
@@ -6146,6 +6344,8 @@ Particular Structures
@defmac AC_STRUCT_DIRENT_D_TYPE
@acindex{STRUCT_DIRENT_D_TYPE}
@cvindex HAVE_STRUCT_DIRENT_D_TYPE
address@hidden @caindex header_dirent_dirent_h
address@hidden @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}.
@@ -6157,11 +6357,15 @@ Particular Structures
@cvindex HAVE_STRUCT_STAT_ST_BLOCKS
@cvindex HAVE_ST_BLOCKS
@ovindex LIBOBJS
address@hidden 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
@@ -6184,6 +6388,8 @@ Particular Structures
@cvindex HAVE_STRUCT_TM_TM_ZONE
@cvindex HAVE_TM_ZONE
@cvindex HAVE_TZNAME
address@hidden @caindex member_struct_tm_tm_zone
address@hidden @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
@@ -6201,6 +6407,7 @@ Generic Structures
@ovar{action-if-found}, @ovar{action-if-not-found}, @
@dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_MEMBER}
address@hidden address@hidden@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}).
@@ -6216,6 +6423,10 @@ Generic Structures
@example
AC_CHECK_MEMBER(struct top.middle.bot)
@end example
+
+This macro caches its result in the
address@hidden@address@hidden variable, with characters not
+suitable for a variable name mapped to underscores.
@end defmac
@anchor{AC_CHECK_MEMBERS}
@@ -6276,14 +6487,19 @@ Particular Types
@defmac AC_TYPE_GETGROUPS
@acindex{TYPE_GETGROUPS}
@cvindex GETGROUPS_T
address@hidden 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
address@hidden 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
@@ -6301,12 +6517,15 @@ Particular Types
@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
address@hidden c_int16_t
This is like @code{AC_TYPE_INT8_T}, except for 16-bit integers.
@end defmac
@@ -6314,6 +6533,7 @@ Particular Types
@acindex{TYPE_INT32_T}
@cvindex HAVE_INT32_T
@cvindex int32_t
address@hidden c_int32_t
This is like @code{AC_TYPE_INT8_T}, except for 32-bit integers.
@end defmac
@@ -6321,6 +6541,7 @@ Particular Types
@acindex{TYPE_INT64_T}
@cvindex HAVE_INT64_T
@cvindex int64_t
address@hidden c_int64_t
This is like @code{AC_TYPE_INT8_T}, except for 64-bit integers.
@end defmac
@@ -6328,6 +6549,7 @@ Particular Types
@acindex{TYPE_INTMAX_T}
@cvindex HAVE_INTMAX_T
@cvindex intmax_t
address@hidden @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.
@@ -6337,6 +6559,7 @@ Particular Types
@acindex{TYPE_INTPTR_T}
@cvindex HAVE_INTPTR_T
@cvindex intptr_t
address@hidden @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
@@ -6346,10 +6569,14 @@ Particular Types
@defmac AC_TYPE_LONG_DOUBLE
@acindex{TYPE_LONG_DOUBLE}
@cvindex HAVE_LONG_DOUBLE
address@hidden 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
@@ -6357,67 +6584,94 @@ Particular Types
@defmac AC_TYPE_LONG_DOUBLE_WIDER
@acindex{TYPE_LONG_DOUBLE_WIDER}
@cvindex HAVE_LONG_DOUBLE_WIDER
address@hidden 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
address@hidden 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}
address@hidden 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
address@hidden 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
address@hidden 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
address@hidden 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
address@hidden 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
address@hidden 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}
@@ -6425,14 +6679,18 @@ Particular Types
@acindex{TYPE_UID_T}
@cvindex uid_t
@cvindex gid_t
address@hidden 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
address@hidden 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
@@ -6444,6 +6702,7 @@ Particular Types
@acindex{TYPE_UINT16_T}
@cvindex HAVE_UINT16_T
@cvindex uint16_t
address@hidden c_uint16_t
This is like @code{AC_TYPE_UINT8_T}, except for 16-bit integers.
@end defmac
@@ -6451,6 +6710,7 @@ Particular Types
@acindex{TYPE_UINT32_T}
@cvindex HAVE_UINT32_T
@cvindex uint32_t
address@hidden c_uint32_t
This is like @code{AC_TYPE_UINT8_T}, except for 32-bit integers.
@end defmac
@@ -6458,6 +6718,7 @@ Particular Types
@acindex{TYPE_UINT64_T}
@cvindex HAVE_UINT64_T
@cvindex uint64_t
address@hidden c_uint64_t
This is like @code{AC_TYPE_UINT8_T}, except for 64-bit integers.
@end defmac
@@ -6465,6 +6726,7 @@ Particular Types
@acindex{TYPE_UINTMAX_T}
@cvindex HAVE_UINTMAX_T
@cvindex uintmax_t
address@hidden @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.
@@ -6474,6 +6736,7 @@ Particular Types
@acindex{TYPE_UINTPTR_T}
@cvindex HAVE_UINTPTR_T
@cvindex uintptr_t
address@hidden @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
@@ -6483,11 +6746,15 @@ Particular Types
@defmac AC_TYPE_UNSIGNED_LONG_LONG_INT
@acindex{TYPE_UNSIGNED_LONG_LONG_INT}
@cvindex HAVE_UNSIGNED_LONG_LONG_INT
address@hidden 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
@@ -6499,6 +6766,7 @@ 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}
address@hidden address@hidden
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
@@ -6509,6 +6777,10 @@ Generic Types
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 @address@hidden
+variable, with @samp{*} mapped to @samp{p} and other characters not
+suitable for a variable name mapped to underscores.
@end defmac
@@ -6607,6 +6879,7 @@ Generic Compiler Characteristics
@dvar{includes, AC_INCLUDES_DEFAULT})
@acindex{CHECK_SIZEOF}
@cvindex address@hidden
address@hidden address@hidden
Define @address@hidden (@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
@@ -6626,16 +6899,25 @@ Generic Compiler Characteristics
@noindent
defines @code{SIZEOF_INT_P} to be 8 on DEC Alpha AXP systems.
+
+This macro caches its result in the @address@hidden
+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 address@hidden
address@hidden address@hidden
Define @address@hidden (@pxref{Standard Symbols}) to be the
alignment in bytes of @var{type}. @address@hidden 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 @address@hidden
+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}, @
@@ -6783,6 +7065,7 @@ C Compiler
@evindex CFLAGS
@ovindex CC
@ovindex CFLAGS
address@hidden 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
@@ -6830,12 +7113,16 @@ C Compiler
@defmac AC_PROG_CC_C_O
@acindex{PROG_CC_C_O}
@cvindex NO_MINUS_C_MINUS_O
address@hidden address@hidden
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
address@hidden@var{compiler}_c_o} variable.
@end defmac
@@ -6873,6 +7160,7 @@ C Compiler
@defmac AC_PROG_CC_STDC
@acindex{PROG_CC_STDC}
address@hidden 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
@@ -6885,6 +7173,7 @@ C Compiler
@defmac AC_PROG_CC_C89
@acindex{PROG_CC_C89}
address@hidden 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
@@ -6901,6 +7190,7 @@ C Compiler
@defmac AC_PROG_CC_C99
@acindex{PROG_CC_C99}
address@hidden 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
@@ -6970,6 +7260,7 @@ C Compiler
@defmac AC_C_CONST
@acindex{C_CONST}
@cvindex const
address@hidden 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
@@ -6996,6 +7287,8 @@ C Compiler
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
@@ -7003,6 +7296,7 @@ C Compiler
@defmac AC_C_RESTRICT
@acindex{C_RESTRICT}
@cvindex restrict
address@hidden 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
@@ -7017,6 +7311,9 @@ C Compiler
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
@@ -7802,6 +8099,7 @@ System Services
@acindex{SYS_POSIX_TERMIOS}
@cindex Posix termios headers
@cindex termios Posix headers
address@hidden 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}.
--
1.6.3.2.388.gb7132
- [PATCH 1/5] Document AM_MAKEFLAGS workaround to the macro override problem., (continued)
- [PATCH 3/5] New cache variable index in the manual., Ralf Wildenhues, 2009/09/13
- [PATCH 4/5] Documentation of specific and general cache variables.,
Ralf Wildenhues <=
[PATCH 5/5] Use consistent notation for cache variables., Ralf Wildenhues, 2009/09/13