| |
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
Defining 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 defined via AC_DEFINE.
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.])
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_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.
|
|
