www.delorie.com/gnu/docs/autoconf/autoconf_30.html   search  
 
Buy the book!


Autoconf

[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

4.8.3 Autoheader Macros

autoheader scans `configure.ac' and figures out which C preprocessor symbols it might define. It knows how to generate templates for symbols defined by AC_CHECK_HEADERS, AC_CHECK_FUNCS etc., but if you AC_DEFINE any additional symbol, you must define a template for it. If there are missing templates, autoheader fails with an error message.

The simplest way to create a template for a symbol is to supply the description argument to an `AC_DEFINE(symbol)'; see 7.1 Defining C Preprocessor Symbols. You may also use one of the following macros.

Macro: AH_VERBATIM (key, template)
Tell autoheader to include the template as-is in the header template file. This template is associated with the key, which is used to sort all the different templates and guarantee their uniqueness. It should be a symbol that can be AC_DEFINE'd.

For example:

 
AH_VERBATIM([_GNU_SOURCE],
[/* Enable GNU extensions on systems that have them.  */
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif])

Macro: AH_TEMPLATE (key, description)
Tell autoheader to generate a template for key. This macro generates standard templates just like AC_DEFINE when a description is given.

For example:

 
AH_TEMPLATE([CRAY_STACKSEG_END],
            [Define to one of _getb67, GETB67, getb67
             for Cray-2 and Cray-YMP systems.  This
             function is required for alloca.c support
             on those systems.])

will generate the following template, with the description properly justified.

 
/* Define to one of _getb67, GETB67, getb67 for Cray-2 and
   Cray-YMP systems.  This function is required for alloca.c
   support on those systems.  */
#undef CRAY_STACKSEG_END

Macro: AH_TOP (text)
Include text at the top of the header template file.

Macro: AH_BOTTOM (text)
Include text at the bottom of the header template file.


[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

  webmaster   donations   bookstore     delorie software   privacy  
  Copyright 2003   by The Free Software Foundation     Updated Jun 2003