(autoconf.info)Autoheader Macros


Prev: autoheader Invocation Up: Configuration Headers

4.9.3 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 template for a SYMBOL is created by `autoheader' from the
DESCRIPTION argument to an `AC_DEFINE'; see Note: Defining Symbols.

   For special needs, you can use the following macros.

 -- 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.])

     generates 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_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 defined via
     `AC_DEFINE'.

 -- 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.

   Please note that TEXT gets included "verbatim" to the template file,
not to the resulting config header, so it can easily get mangled when
the template is processed.  There is rarely a need for something other
than

     AH_BOTTOM([#include <custom.h>])


automatically generated by info2www