NAME
gpt-undefines - Generate a list of preprocessor macros that are not
defined.
SYNOPSIS
gpt-undefines [-srcdir=PATH -config -disable-undefs -verbose -help]
headers containing defines
DESCRIPTION
gpt-undefines Generates a list of preprocessor macros that are not
defined internally in the source code. Macros that are defined in the
header files listed during gpt-undefines’s invocation will also be
excluded.
OPTIONS
-srcdir=PATH
Use PATH as the directory containing the source code. Source code
in the entire directory tree will be scanned. Default PATH is the
directory gpt-undefines was invoked in.
-config
Prints the list out in a format that can be pasted into an
installable header file.
-disable-undefs
Do not count commented out undefines as a define. This technique is
used by autoconf to indicate a negative test result. Example:
/* #undef HAVE_TCP_FASTACK */
Managing Autoconf defines.
By default the defines tested for by the configure script are stored in
a file called config.h. This file should never be installed. to add
autoconf defines to config.h simply add the define in the following
format to the file acconfig.h:
#undef AUTOCONF_DEFINE
acconfig.h is tranformed into a config.h.in by the script autoheader.
Then the configure script transform it into config.h.
A problem occurs when the autoconf defines are used in installed header
files. In this case the defines should be put in an installable header
file using the following format:
#ifndef AUTOCONF_DEFINE
#undef AUTOCONF_DEFINE
#endif
SEE ALSO
autoconf(1) autoheader(1)
AUTHOR
Michael Bletzinger <mbletzin.ncsa.uiuc.edu> and Eric Blau
<eblau.ncsa.uiuc.edu>