This is Info file autoconf.info, produced by Makeinfo-1.55 from the
input file autoconf.texi.

START-INFO-DIR-ENTRY
* Autoconf: (autoconf).         Create source code configuration scripts.
END-INFO-DIR-ENTRY

   Autoconf: Creating Automatic Configuration Scripts, by David
MacKenzie.

   This file documents the GNU Autoconf package for creating scripts to
configure source code packages using templates and an `m4' macro
package.

   Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Foundation.


File: autoconf.info,  Node: Numbers,  Next: Deuteronomy,  Prev: Leviticus,  Up: History

Numbers
=======

   In July 1992, after months of alpha testing, I released Autoconf 1.0,
and converted many GNU packages to use it.  I was surprised by how
positive the reaction to it was.  More people started using it than I
could keep track of, including people working on software that wasn't
part of the GNU Project (such as TCL, FSP, and Kerberos V5).  Autoconf
continued to improve rapidly, as many people using the `configure'
scripts reported problems they encountered.

   Autoconf turned out to be a good torture test for `m4'
implementations.  UNIX `m4' started to dump core because of the length
of the macros that Autoconf defined, and several bugs showed up in GNU
`m4' as well.  Eventually, we realized that we needed to use some
features that only GNU `m4' has.  4.3BSD `m4', in particular, has an
impoverished set of builtin macros; the System V version is better, but
still doesn't provide everything we need.

   More development occurred as people put Autoconf under more stresses
(and to uses I hadn't anticipated).  Karl Berry added checks for X11.
david zuhn contributed C++ support.  Franc,ois Pinard made it diagnose
invalid arguments.  Jim Blandy bravely coerced it into configuring GNU
Emacs, laying the groundwork for several later improvements.  Roland
McGrath got it to configure the GNU C Library, wrote the `autoheader'
script to automate the creation of C header file templates, and added a
`--verbose' option to `configure'.  Noah Friedman added the
`--macrodir' option and `AC_MACRODIR' environment variable.  (He also
coined the term "autoconfiscate" to mean "adapt a software package to
use Autoconf".)  Roland and Noah improved the quoting protection in
`AC_DEFINE' and fixed many bugs, especially when I got sick of dealing
with portability problems from February through June, 1993.


File: autoconf.info,  Node: Deuteronomy,  Prev: Numbers,  Up: History

Deuteronomy
===========

   A long wish list for major features had accumulated, and the effect
of several years of patching by various people had left some residual
cruft.  In April 1994, while working for Cygnus Support, I began a major
revision of Autoconf.  I added most of the features of the Cygnus
`configure' that Autoconf had lacked, largely by adapting the relevant
parts of Cygnus `configure' with the help of david zuhn and Ken
Raeburn.  These features include support for using `config.sub',
`config.guess', `--host', and `--target'; making links to files; and
running `configure' scripts in subdirectories.  Adding these features
enabled Ken to convert GNU `as', and Rob Savoye to convert DejaGNU, to
using Autoconf.

   I added more features in response to other peoples' requests.  Many
people had asked for `configure' scripts to share the results of the
checks between runs, because (particularly when configuring a large
source tree, like Cygnus does) they were frustratingly slow.  Mike
Haertel suggested adding site-specific initialization scripts.  People
distributing software that had to unpack on MS-DOS asked for a way to
override the `.in' extension on the file names, which produced file
names like `config.h.in' containing two dots.  Jim Avera did an
extensive examination of the problems with quoting in `AC_DEFINE' and
`AC_SUBST'; his insights led to significant improvements.  Richard
Stallman asked that compiler output be sent to `config.log' instead of
`/dev/null', to help people debug the Emacs `configure' script.

   I made some other changes because of my dissatisfaction with the
quality of the program.  I made the messages showing results of the
checks less ambiguous, always printing a result.  I regularized the
names of the macros and cleaned up coding style inconsistencies.  I
added some auxiliary utilities that I had developed to help convert
source code packages to use Autoconf.  With the help of Franc,ois
Pinard, I made the macros not interrupt each others' messages.  (That
feature revealed some performance bottlenecks in GNU `m4', which he
hastily corrected!) I reorganized the documentation around problems
people want to solve.  And I began a testsuite, because experience had
shown that Autoconf has a pronounced tendency to regress when we change
it.

   Again, several alpha testers gave invaluable feedback, especially
Franc,ois Pinard, Jim Meyering, Karl Berry, Rob Savoye, Ken Raeburn,
and Mark Eichin.

   Finally, version 2.0 was ready.  And there was much rejoicing.  (And
I have free time again.  I think.  Yeah, right.)


File: autoconf.info,  Node: Old Macro Names,  Next: Environment Variable Index,  Prev: History,  Up: Top

Old Macro Names
***************

   In version 2 of Autoconf, most of the macros were renamed to use a
more uniform and descriptive naming scheme.  Here are the old names of
the macros that were renamed, followed by the current names of those
macros.  Although the old names are still accepted by the `autoconf'
program for backward compatibility, the old names are considered
obsolete.  *Note Macro Names::, for a description of the new naming
scheme.

`AC_ALLOCA'
     `AC_FUNC_ALLOCA'

`AC_ARG_ARRAY'
     removed because of limited usefulness

`AC_CHAR_UNSIGNED'
     `AC_C_CHAR_UNSIGNED'

`AC_CONST'
     `AC_C_CONST'

`AC_CROSS_CHECK'
     `AC_C_CROSS'

`AC_ERROR'
     `AC_MSG_ERROR'

`AC_FIND_X'
     `AC_PATH_X'

`AC_FIND_XTRA'
     `AC_PATH_XTRA'

`AC_FUNC_CHECK'
     `AC_CHECK_FUNC'

`AC_GCC_TRADITIONAL'
     `AC_PROG_GCC_TRADITIONAL'

`AC_GETGROUPS_T'
     `AC_TYPE_GETGROUPS'

`AC_GETLOADAVG'
     `AC_FUNC_GETLOADAVG'

`AC_HAVE_FUNCS'
     `AC_CHECK_FUNCS'

`AC_HAVE_HEADERS'
     `AC_CHECK_HEADERS'

`AC_HAVE_POUNDBANG'
     `AC_SYS_INTERPRETER' (different calling convention)

`AC_HEADER_CHECK'
     `AC_CHECK_HEADER'

`AC_HEADER_EGREP'
     `AC_EGREP_HEADER'

`AC_INLINE'
     `AC_C_INLINE'

`AC_LN_S'
     `AC_PROG_LN_S'

`AC_LONG_DOUBLE'
     `AC_C_LONG_DOUBLE'

`AC_LONG_FILE_NAMES'
     `AC_SYS_LONG_FILE_NAMES'

`AC_MAJOR_HEADER'
     `AC_HEADER_MAJOR'

`AC_MINUS_C_MINUS_O'
     `AC_PROG_CC_C_O'

`AC_MMAP'
     `AC_FUNC_MMAP'

`AC_MODE_T'
     `AC_TYPE_MODE_T'

`AC_OFF_T'
     `AC_TYPE_OFF_T'

`AC_PID_T'
     `AC_TYPE_PID_T'

`AC_PREFIX'
     `AC_PREFIX_PROGRAM'

`AC_PROGRAMS_CHECK'
     `AC_CHECK_PROGS'

`AC_PROGRAMS_PATH'
     `AC_PATH_PROGS'

`AC_PROGRAM_CHECK'
     `AC_CHECK_PROG'

`AC_PROGRAM_EGREP'
     `AC_EGREP_CPP'

`AC_PROGRAM_PATH'
     `AC_PATH_PROG'

`AC_REMOTE_TAPE'
     removed because of limited usefulness

`AC_RESTARTABLE_SYSCALLS'
     `AC_SYS_RESTARTABLE_SYSCALLS'

`AC_RETSIGTYPE'
     `AC_TYPE_SIGNAL'

`AC_RSH'
     removed because of limited usefulness

`AC_SETVBUF_REVERSED'
     `AC_FUNC_SETVBUF_REVERSED'

`AC_SET_MAKE'
     `AC_PROG_MAKE_SET'

`AC_SIZEOF_TYPE'
     `AC_CHECK_SIZEOF'

`AC_SIZE_T'
     `AC_TYPE_SIZE_T'

`AC_STAT_MACROS_BROKEN'
     `AC_HEADER_STAT'

`AC_STDC_HEADERS'
     `AC_HEADER_STDC'

`AC_STRCOLL'
     `AC_FUNC_STRCOLL'

`AC_ST_BLKSIZE'
     `AC_STRUCT_ST_BLKSIZE'

`AC_ST_BLOCKS'
     `AC_STRUCT_ST_BLOCKS'

`AC_ST_RDEV'
     `AC_STRUCT_ST_RDEV'

`AC_SYS_SIGLIST_DECLARED'
     `AC_DECL_SYS_SIGLIST'

`AC_TEST_CPP'
     `AC_TRY_CPP'

`AC_TEST_PROGRAM'
     `AC_TRY_RUN'

`AC_TIMEZONE'
     `AC_STRUCT_TIMEZONE'

`AC_TIME_WITH_SYS_TIME'
     `AC_HEADER_TIME'

`AC_UID_T'
     `AC_TYPE_UID_T'

`AC_UTIME_NULL'
     `AC_FUNC_UTIME_NULL'

`AC_VFORK'
     `AC_FUNC_VFORK'

`AC_VPRINTF'
     `AC_FUNC_VPRINTF'

`AC_WAIT3'
     `AC_FUNC_WAIT3'

`AC_WARN'
     `AC_MSG_WARN'

`AC_WORDS_BIGENDIAN'
     `AC_C_BIGENDIAN'

`AC_YYTEXT_POINTER'
     `AC_DECL_YYTEXT'


File: autoconf.info,  Node: Environment Variable Index,  Next: Output Variable Index,  Prev: Old Macro Names,  Up: Top

Environment Variable Index
**************************

   This is an alphabetical list of the environment variables that
Autoconf checks.

* Menu:

* AC_MACRODIR:                          Invoking autoupdate.
* AC_MACRODIR:                          Invoking autoheader.
* AC_MACRODIR:                          Invoking autoreconf.
* AC_MACRODIR:                          Invoking autoconf.
* AC_MACRODIR:                          Invoking ifnames.
* AC_MACRODIR:                          Invoking autoscan.
* CONFIG_FILES:                         Invoking config.status.
* CONFIG_HEADERS:                       Invoking config.status.
* CONFIG_SHELL:                         Invoking config.status.
* CONFIG_SITE:                          Site Defaults.
* CONFIG_STATUS:                        Invoking config.status.
* SIMPLE_BACKUP_SUFFIX:                 Invoking autoupdate.


File: autoconf.info,  Node: Output Variable Index,  Next: Preprocessor Symbol Index,  Prev: Environment Variable Index,  Up: Top

Output Variable Index
*********************

   This is an alphabetical list of the variables that Autoconf can
substitute into files that it creates, typically one or more
`Makefile's.  *Note Setting Output Variables::, for more information on
how this is done.

* Menu:

* ALLOCA:                               Particular Functions.
* AWK:                                  Particular Programs.
* build:                                System Type Variables.
* build_alias:                          System Type Variables.
* build_cpu:                            System Type Variables.
* build_os:                             System Type Variables.
* build_vendor:                         System Type Variables.
* CC:                                   UNIX Variants.
* CC:                                   Particular Programs.
* CC:                                   Particular Programs.
* CFLAGS:                               Particular Programs.
* CFLAGS:                               Preset Output Variables.
* configure_input:                      Preset Output Variables.
* CPP:                                  Particular Programs.
* CPPFLAGS:                             Preset Output Variables.
* CXX:                                  Particular Programs.
* CXXCPP:                               Particular Programs.
* CXXFLAGS:                             Particular Programs.
* CXXFLAGS:                             Preset Output Variables.
* DEFS:                                 Preset Output Variables.
* exec_prefix:                          Preset Output Variables.
* host:                                 System Type Variables.
* host_alias:                           System Type Variables.
* host_cpu:                             System Type Variables.
* host_os:                              System Type Variables.
* host_vendor:                          System Type Variables.
* INSTALL:                              Particular Programs.
* INSTALL_DATA:                         Particular Programs.
* INSTALL_PROGRAM:                      Particular Programs.
* KMEM_GROUP:                           Particular Functions.
* LDFLAGS:                              Preset Output Variables.
* LEX:                                  Particular Programs.
* LEXLIB:                               Particular Programs.
* LEX_OUTPUT_ROOT:                      Particular Programs.
* LIBOBJS:                              Structures.
* LIBOBJS:                              Generic Functions.
* LIBOBJS:                              Particular Functions.
* LIBOBJS:                              Particular Functions.
* LIBS:                                 UNIX Variants.
* LIBS:                                 UNIX Variants.
* LIBS:                                 Preset Output Variables.
* LN_S:                                 Particular Programs.
* NEED_SETGID:                          Particular Functions.
* prefix:                               Preset Output Variables.
* program_transform_name:               Transforming Names.
* RANLIB:                               Particular Programs.
* SET_MAKE:                             Output.
* srcdir:                               Preset Output Variables.
* subdirs:                              Subdirectories.
* target:                               System Type Variables.
* target_alias:                         System Type Variables.
* target_cpu:                           System Type Variables.
* target_os:                            System Type Variables.
* target_vendor:                        System Type Variables.
* top_srcdir:                           Preset Output Variables.
* X_CFLAGS:                             System Services.
* X_EXTRA_LIBS:                         System Services.
* X_LIBS:                               System Services.
* X_PRE_LIBS:                           System Services.
* YACC:                                 Particular Programs.


File: autoconf.info,  Node: Preprocessor Symbol Index,  Next: Macro Index,  Prev: Output Variable Index,  Up: Top

Preprocessor Symbol Index
*************************

   This is an alphabetical list of the C preprocessor symbols that the
Autoconf macros define.  To work with Autoconf, C source code needs to
use these names in `#if' directives.

* Menu:

* CLOSEDIR_VOID:                        Particular Functions.
* const:                                Compiler Characteristics.
* C_ALLOCA:                             Particular Functions.
* DGUX:                                 Particular Functions.
* DIRENT:                               Particular Headers.
* GETGROUPS_T:                          Particular Typedefs.
* GETLODAVG_PRIVILEGED:                 Particular Functions.
* GETPGRP_VOID:                         Particular Functions.
* gid_t:                                Particular Typedefs.
* HAVE_FUNCTION:                        Generic Functions.
* HAVE_HEADER:                          Generic Headers.
* HAVE_ALLOCA_H:                        Particular Functions.
* HAVE_CONFIG_H:                        Configuration Headers.
* HAVE_DIRENT_H:                        Particular Headers.
* HAVE_DOPRNT:                          Particular Functions.
* HAVE_GETMNTENT:                       Particular Functions.
* HAVE_LONG_DOUBLE:                     Compiler Characteristics.
* HAVE_LONG_FILE_NAMES:                 System Services.
* HAVE_MMAP:                            Particular Functions.
* HAVE_NDIR_H:                          Particular Headers.
* HAVE_RESTARTABLE_SYSCALLS:            System Services.
* HAVE_STRCOLL:                         Particular Functions.
* HAVE_STRFTIME:                        Particular Functions.
* HAVE_ST_BLKSIZE:                      Structures.
* HAVE_ST_BLOCKS:                       Structures.
* HAVE_ST_RDEV:                         Structures.
* HAVE_SYS_DIR_H:                       Particular Headers.
* HAVE_SYS_NDIR_H:                      Particular Headers.
* HAVE_SYS_WAIT_H:                      Particular Headers.
* HAVE_TM_ZONE:                         Structures.
* HAVE_TZNAME:                          Structures.
* HAVE_UNISTD_H:                        Particular Headers.
* HAVE_UTIME_NULL:                      Particular Functions.
* HAVE_VFORK_H:                         Particular Functions.
* HAVE_VPRINTF:                         Particular Functions.
* HAVE_WAIT3:                           Particular Functions.
* inline:                               Compiler Characteristics.
* INT_16_BITS:                          Compiler Characteristics.
* LONG_64_BITS:                         Compiler Characteristics.
* MAJOR_IN_MKDEV:                       Particular Headers.
* MAJOR_IN_SYSMACROS:                   Particular Headers.
* mode_t:                               Particular Typedefs.
* NDIR:                                 Particular Headers.
* NEED_MEMORY_H:                        Particular Headers.
* NEED_SETGID:                          Particular Functions.
* NLIST_NAME_UNION:                     Particular Functions.
* NLIST_STRUCT:                         Particular Functions.
* NO_MINUS_C_MINUS_O:                   Particular Programs.
* off_t:                                Particular Typedefs.
* pid_t:                                Particular Typedefs.
* RETSIGTYPE:                           Particular Typedefs.
* SETVBUF_REVERSED:                     Particular Functions.
* size_t:                               Particular Typedefs.
* STDC_HEADERS:                         Particular Headers.
* SVR4:                                 Particular Functions.
* SYSDIR:                               Particular Headers.
* SYSNDIR:                              Particular Headers.
* SYS_SIGLIST_DECLARED:                 Particular Headers.
* TIME_WITH_SYS_TIME:                   Structures.
* TM_IN_SYS_TIME:                       Structures.
* uid_t:                                Particular Typedefs.
* UMAX:                                 Particular Functions.
* UMAX4_3:                              Particular Functions.
* USG:                                  Particular Headers.
* vfork:                                Particular Functions.
* VOID_CLOSEDIR:                        Particular Headers.
* WORDS_BIGENDIAN:                      Compiler Characteristics.
* YYTEXT_POINTER:                       Particular Programs.
* _ALL_SOURCE:                          UNIX Variants.
* _MINIX:                               UNIX Variants.
* _POSIX_1_SOURCE:                      UNIX Variants.
* _POSIX_SOURCE:                        UNIX Variants.
* _POSIX_SOURCE:                        UNIX Variants.
* _POSIX_VERSION:                       Particular Headers.
* __CHAR_UNSIGNED__:                    Compiler Characteristics.


File: autoconf.info,  Node: Macro Index,  Prev: Preprocessor Symbol Index,  Up: Top

Macro Index
***********

   This is an alphabetical list of the Autoconf macros.  To make the
list easier to use, the macros are listed without their preceding `AC_'.

* Menu:

* AIX:                                  UNIX Variants.
* ALLOCA:                               Old Macro Names.
* ARG_ARRAY:                            Old Macro Names.
* ARG_ENABLE:                           Package Options.
* ARG_PROGRAM:                          Transforming Names.
* ARG_WITH:                             External Software.
* BEFORE:                               Suggested Ordering.
* CACHE_VAL:                            Caching Results.
* CANONICAL_HOST:                       Canonicalizing.
* CANONICAL_SYSTEM:                     Canonicalizing.
* CHAR_UNSIGNED:                        Old Macro Names.
* CHECKING:                             Printing Messages.
* CHECK_FUNC:                           Generic Functions.
* CHECK_FUNCS:                          Generic Functions.
* CHECK_HEADER:                         Generic Headers.
* CHECK_HEADERS:                        Generic Headers.
* CHECK_LIB:                            Libraries.
* CHECK_PROG:                           Generic Programs.
* CHECK_PROGS:                          Generic Programs.
* CHECK_SIZEOF:                         Compiler Characteristics.
* CHECK_TOOL:                           Generic Programs.
* CHECK_TYPE:                           Generic Typedefs.
* COMPILE_CHECK:                        Examining Libraries.
* CONFIG_AUX_DIR:                       Input.
* CONFIG_HEADER:                        Configuration Headers.
* CONFIG_SUBDIRS:                       Subdirectories.
* CONST:                                Old Macro Names.
* CROSS_CHECK:                          Old Macro Names.
* C_BIGENDIAN:                          Compiler Characteristics.
* C_CHAR_UNSIGNED:                      Compiler Characteristics.
* C_CONST:                              Compiler Characteristics.
* C_CROSS:                              Test Programs.
* C_INLINE:                             Compiler Characteristics.
* C_LONG_DOUBLE:                        Compiler Characteristics.
* DECL_SYS_SIGLIST:                     Particular Headers.
* DECL_YYTEXT:                          Particular Programs.
* DEFINE:                               Defining Symbols.
* DEFINE_UNQUOTED:                      Defining Symbols.
* DEFUN:                                Macro Definitions.
* DIR_HEADER:                           Particular Headers.
* DYNIX_SEQ:                            UNIX Variants.
* EGREP_CPP:                            Examining Declarations.
* EGREP_HEADER:                         Examining Declarations.
* ENABLE:                               Package Options.
* ERROR:                                Old Macro Names.
* FIND_X:                               Old Macro Names.
* FIND_XTRA:                            Old Macro Names.
* FUNC_ALLOCA:                          Particular Functions.
* FUNC_CHECK:                           Old Macro Names.
* FUNC_CLOSEDIR_VOID:                   Particular Functions.
* FUNC_GETLOADAVG:                      Particular Functions.
* FUNC_GETMNTENT:                       Particular Functions.
* FUNC_GETPGRP:                         Particular Functions.
* FUNC_MEMCMP:                          Particular Functions.
* FUNC_MMAP:                            Particular Functions.
* FUNC_SETVBUF_REVERSED:                Particular Functions.
* FUNC_STRCOLL:                         Particular Functions.
* FUNC_STRFTIME:                        Particular Functions.
* FUNC_UTIME_NULL:                      Particular Functions.
* FUNC_VFORK:                           Particular Functions.
* FUNC_VPRINTF:                         Particular Functions.
* FUNC_WAIT3:                           Particular Functions.
* GCC_TRADITIONAL:                      Old Macro Names.
* GETGROUPS_T:                          Old Macro Names.
* GETLOADAVG:                           Old Macro Names.
* HAVE_FUNCS:                           Old Macro Names.
* HAVE_HEADERS:                         Old Macro Names.
* HAVE_LIBRARY:                         Libraries.
* HAVE_POUNDBANG:                       Old Macro Names.
* HEADER_CHECK:                         Old Macro Names.
* HEADER_DIRENT:                        Particular Headers.
* HEADER_EGREP:                         Old Macro Names.
* HEADER_MAJOR:                         Particular Headers.
* HEADER_STAT:                          Structures.
* HEADER_STDC:                          Particular Headers.
* HEADER_SYS_WAIT:                      Particular Headers.
* HEADER_TIME:                          Structures.
* INIT:                                 Input.
* INLINE:                               Old Macro Names.
* INT_16_BITS:                          Compiler Characteristics.
* IRIX_SUN:                             UNIX Variants.
* ISC_POSIX:                            UNIX Variants.
* LANG_C:                               Language Choice.
* LANG_CPLUSPLUS:                       Language Choice.
* LANG_RESTORE:                         Language Choice.
* LANG_SAVE:                            Language Choice.
* LINK_FILES:                           Using System Type.
* LN_S:                                 Old Macro Names.
* LONG_64_BITS:                         Compiler Characteristics.
* LONG_DOUBLE:                          Old Macro Names.
* LONG_FILE_NAMES:                      Old Macro Names.
* MAJOR_HEADER:                         Old Macro Names.
* MEMORY_H:                             Particular Headers.
* MINIX:                                UNIX Variants.
* MINUS_C_MINUS_O:                      Old Macro Names.
* MMAP:                                 Old Macro Names.
* MODE_T:                               Old Macro Names.
* MSG_CHECKING:                         Printing Messages.
* MSG_ERROR:                            Printing Messages.
* MSG_RESULT:                           Printing Messages.
* MSG_WARN:                             Printing Messages.
* OBSOLETE:                             Obsolete Macros.
* OFF_T:                                Old Macro Names.
* OUTPUT:                               Output.
* PATH_PROG:                            Generic Programs.
* PATH_PROGS:                           Generic Programs.
* PATH_X:                               System Services.
* PATH_XTRA:                            System Services.
* PID_T:                                Old Macro Names.
* PREFIX:                               Old Macro Names.
* PREFIX_PROGRAM:                       Default Prefix.
* PREREQ:                               Versions.
* PROGRAMS_CHECK:                       Old Macro Names.
* PROGRAMS_PATH:                        Old Macro Names.
* PROGRAM_CHECK:                        Old Macro Names.
* PROGRAM_EGREP:                        Old Macro Names.
* PROGRAM_PATH:                         Old Macro Names.
* PROG_AWK:                             Particular Programs.
* PROG_CC:                              Particular Programs.
* PROG_CC_C_O:                          Particular Programs.
* PROG_CPP:                             Particular Programs.
* PROG_CXX:                             Particular Programs.
* PROG_CXXCPP:                          Particular Programs.
* PROG_GCC_TRADITIONAL:                 Particular Programs.
* PROG_INSTALL:                         Particular Programs.
* PROG_LEX:                             Particular Programs.
* PROG_LN_S:                            Particular Programs.
* PROG_MAKE_SET:                        Output.
* PROG_RANLIB:                          Particular Programs.
* PROG_YACC:                            Particular Programs.
* PROVIDE:                              Prerequisite Macros.
* REMOTE_TAPE:                          Old Macro Names.
* REPLACE_FUNCS:                        Generic Functions.
* REQUIRE:                              Prerequisite Macros.
* REQUIRE_CPP:                          Language Choice.
* RESTARTABLE_SYSCALLS:                 Old Macro Names.
* RETSIGTYPE:                           Old Macro Names.
* REVISION:                             Versions.
* RSH:                                  Old Macro Names.
* SCO_INTL:                             UNIX Variants.
* SETVBUF_REVERSED:                     Old Macro Names.
* SET_MAKE:                             Old Macro Names.
* SIZEOF_TYPE:                          Old Macro Names.
* SIZE_T:                               Old Macro Names.
* STAT_MACROS_BROKEN:                   Old Macro Names.
* STAT_MACROS_BROKEN:                   Structures.
* STDC_HEADERS:                         Old Macro Names.
* STRCOLL:                              Old Macro Names.
* STRUCT_ST_BLKSIZE:                    Structures.
* STRUCT_ST_BLOCKS:                     Structures.
* STRUCT_ST_RDEV:                       Structures.
* STRUCT_TIMEZONE:                      Structures.
* STRUCT_TM:                            Structures.
* ST_BLKSIZE:                           Old Macro Names.
* ST_BLOCKS:                            Old Macro Names.
* ST_RDEV:                              Old Macro Names.
* SUBST:                                Setting Output Variables.
* SUBST_FILE:                           Setting Output Variables.
* SYS_INTERPRETER:                      System Services.
* SYS_LONG_FILE_NAMES:                  System Services.
* SYS_RESTARTABLE_SYSCALLS:             System Services.
* SYS_SIGLIST_DECLARED:                 Old Macro Names.
* TEST_CPP:                             Old Macro Names.
* TEST_PROGRAM:                         Old Macro Names.
* TIMEZONE:                             Old Macro Names.
* TIME_WITH_SYS_TIME:                   Old Macro Names.
* TRY_COMPILE:                          Examining Syntax.
* TRY_CPP:                              Examining Declarations.
* TRY_LINK:                             Examining Libraries.
* TRY_RUN:                              Test Programs.
* TYPE_GETGROUPS:                       Particular Typedefs.
* TYPE_MODE_T:                          Particular Typedefs.
* TYPE_OFF_T:                           Particular Typedefs.
* TYPE_PID_T:                           Particular Typedefs.
* TYPE_SIGNAL:                          Particular Typedefs.
* TYPE_SIZE_T:                          Particular Typedefs.
* TYPE_UID_T:                           Particular Typedefs.
* UID_T:                                Old Macro Names.
* UNISTD_H:                             Particular Headers.
* USG:                                  Particular Headers.
* UTIME_NULL:                           Old Macro Names.
* VERBOSE:                              Printing Messages.
* VFORK:                                Old Macro Names.
* VPRINTF:                              Old Macro Names.
* WAIT3:                                Old Macro Names.
* WARN:                                 Old Macro Names.
* WITH:                                 External Software.
* WORDS_BIGENDIAN:                      Old Macro Names.
* XENIX_DIR:                            UNIX Variants.
* YYTEXT_POINTER:                       Old Macro Names.