-*- outline -*-

Things it might be nice to do someday:

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* Make AC_CHECK_LIB check whether the function is already available
  before checking for the library.  This might involve adding another
  kind of cache variable to indicate whether a given function needs a
  given library.  The current ac_cv_func_ variables are intended to
  indicate whether the function is in the default libraries, but
  actually also take into account whatever value LIBS had when they
  were checked for.

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* Add AC_PROG_CC_POSIX to replace the current ad-hoc macros for AIX,
  Minix, ISC, etc.

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* Use AC_EGREP_CPP instead of AC_TRY_LINK to detect structures and members.

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* Make AC_CHECK_FUNC[S] automatically use any particular macros for the
  listed functions.

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* Select the right CONFIG_SHELL automatically (for Ultrix, Lynx especially.)

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* Doc: Add index of concepts.

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* Doc: Centralize information on POSIX, MS-DOS, cross-compiling, and
  other important topics.

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* Doc: Discuss what Autoconf doesn't do: Makefile rules and
  boilerplate, providing replacement C headers and library functions
  (a consistent ANSI C/POSIX.1 environment).  Lessons learned.
  Advantages to not requiring special external libraries or config
  files or programs.

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* Split up AC_SUBST substitutions using a loop to accomodate shells
  with severely limited here document sizes, if it turns out to be a problem.
  I'm not sure whether the limit is on lines or bytes; if bytes, it
  will be less of a problem than it was with the long lines used for
  creating a header file.

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* Allow [ and ] in egrep patterns and AC_DEFINE args.

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* Supply a template Makefile.in that people can adapt (what GNU hello
  was going to be).

** Have CC, DEFS, etc. substitutions.

** Support all of the GNU standard targets.

** Parameterize with make variables to require as little modification
as necessary.  Maybe via m4?  (Eww, sounds like imake.)

** Make it usable both with and without a header file.

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* Mike Haertel's suggestions.

** Provide a file containing decls for alloca, strings, etc.  acdecls.h?

** Cross compiling:

*** Error messages include instructions for overriding defaults using
config.site.

*** Distribute a config.site corresponding to a hypothetical bare POSIX system with c89.

*** Cache consistency checking: ignore cache if environment
(CC or PATH) differs.

** Site defaults:

*** Convention for consistency checking of env vars and options in config.site so config.site can print obnoxious messages if it doesn't like options or env vars that users use.

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* autoscan: Tell the files that caused inclusion of each macro,
in a dnl comment.  (Seems to be hard.)

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* Look at user contributed macros: prototypes, IEEE double precision math, 
shared libraries, various other things.

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* Test suite: more things to test:
** That the shell scripts produce correct output on some simple data.
** Configuration header files.  That autoheader does the right thing,
   and so does AC_CONFIG_HEADER when autoconf is run.

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