@itemx -m @var{dir}
@evindex AC_MACRODIR
Look for the Autoconf macro files in directory @var{dir} instead of the
-default installation directory.
-You can also set the @code{AC_MACRODIR}
+default installation directory. You can also set the @code{AC_MACRODIR}
environment variable to a directory; this option overrides the
environment variable.
are honored.
@end defmac
-@c FIXME: Currently there is no equivalent to init-cmds, so it is
-@c not really obsolete.
Actually, the full @code{AC_OUTPUT} interface is given below. This use
is strongly discouraged.
You can override an input file name by appending to @var{file} a
colon-separated list of input files. Examples:
-@c FIXME: Hm, this example seem to mean we can use the two lines
-@c together, while obviously it would be wrong. Clarify?
@example
-AC_CONFIG_FILES(Makefile:boiler/top.mk lib/Makefile:boiler/lib.mk)
-AC_CONFIG_FILES(Makefile:boiler/vars.mk:Makefile.in:boiler/rules.mk)
+AC_CONFIG_FILES(Makefile:boiler/top.mk:boiler/bot.mk
+ lib/Makefile:boiler/lib.mk)
@end example
Doing this allows you to keep your file names acceptable to MS-DOS, or
to prepend and/or append boilerplate to the file.
Usually the input file is named @file{@var{header}.in}; however, you can
override the input file name by appending to @var{header}, a
colon-separated list of input files. Examples:
+
@example
-AC_CONFIG_HEADERS(defines.h:defines.hin)
+AC_CONFIG_HEADERS(config.h:config.hin)
AC_CONFIG_HEADERS(defines.h:defs.pre:defines.h.in:defs.post)
@end example
+
@noindent
Doing this allows you to keep your file names acceptable to MS-DOS, or
to prepend and/or append boilerplate to the file.
@defmac AC_PREREQ (@var{version})
@maindex PREREQ
+@cindex Version
Ensure that a recent enough version of Autoconf is being used. If the
version of Autoconf being used to create @code{configure} is earlier
than @var{version}, print an error message on the standard error output
and do not create @code{configure}. For example:
@example
-AC_PREREQ(1.8)
+AC_PREREQ(@value{VERSION})
@end example
This macro is useful if your @file{configure.in} relies on non-obvious
@defmac AC_PROG_YACC
@maindex PROG_YACC
@ovindex YACC
-If @code{bison} is found, set output variable @code{YACC} to
-@samp{bison -y}. Otherwise, if @code{byacc} is found, set @code{YACC}
-to @samp{byacc}. Otherwise set @code{YACC} to @samp{yacc}.
+If @code{bison} is found, set output variable @code{YACC} to @samp{bison
+-y}. Otherwise, if @code{byacc} is found, set @code{YACC} to
+@samp{byacc}. Otherwise set @code{YACC} to @samp{yacc}.
@end defmac
@node Generic Programs, , Particular Programs, Alternative Programs
@defmac AC_CHECK_FILE (@var{file}, @ovar{action-if-found}, @ovar{action-if-not-found})
@maindex CHECK_FILE
-Check whether file @var{file} exists on the native system.
-If it is found, execute @var{action-if-found}, otherwise do
+Check whether file @var{file} exists on the native system. If it is
+found, execute @var{action-if-found}, otherwise do
@var{action-if-not-found}, if given.
@end defmac
Like calling @code{AC_CHECK_FUNCS} using an @var{action-if-not-found}
that adds @samp{@var{function}.o} to the value of the output variable
@code{LIBOBJS}. You can declare a function for which your replacement
-version is used by enclosing the prototype in @samp{#ifndef
-HAVE_@var{function}}. If the system has the function, it probably
+version is used by enclosing the prototype in @samp{#if
+!HAVE_@var{function}}. If the system has the function, it probably
declares it in a header file you should be including, so you shouldn't
redeclare it, lest your declaration conflict.
@end defmac
#if STDC_HEADERS
# include <string.h>
#else
-# ifndef HAVE_STRCHR
+# if !HAVE_STRCHR
# define strchr index
# define strrchr rindex
# endif
char *strchr (), *strrchr ();
-# ifndef HAVE_MEMCPY
+# if !HAVE_MEMCPY
# define memcpy(d, s, n) bcopy ((s), (d), (n))
# define memmove(d, s, n) bcopy ((s), (d), (n))
# endif
Occasionally installers use a C++ compiler to compile C code, typically
because they lack a C compiler. This causes problems with @code{const},
because C and C++ treat @code{const} differently. For example:
+
@example
const int foo;
@end example
+
+@noindent
is valid in C but not in C++. These differences unfortunately cannot be
papered over by defining @code{const} to be empty.
prototypes, you should use @code{ansi2knr}, which comes with the
Ghostscript distribution, to unprotoize function definitions. For
function prototypes, you should first define @code{PARAMS}:
+
@example
#ifndef PARAMS
# if PROTOTYPES
# endif /* no PROTOTYPES */
#endif
@end example
+
+@noindent
then use it this way:
+
@example
size_t my_strlen PARAMS ((const char *));
@end example
@c FIXME: What the heck is this macro doing here? Move it out of
@c the way, in its proper section!!!
-@c FIXME: Explain once for all how the CPP names are built, not everywhere.
@defmac AC_CHECK_SIZEOF (@var{type}, @ovar{cross-size}, @ovar{includes})
@maindex CHECK_SIZEOF
-Define @code{SIZEOF_@var{uctype}} to be the size in bytes of the C (or
-C++) type @var{type} (e.g. @samp{int}, @samp{char *} etc.). If
-@samp{type} is unknown, it gets a size of 0. If no @var{includes} are
-specified, the default includes are used (@pxref{Default Includes}). If
-you provide @var{include}, make sure to include @file{stdio.h} which is
-required for this macro to run.
-
-@var{uctype} is @var{type}, with lowercase converted to uppercase,
-spaces changed to underscores, and asterisks changed to @samp{P}. If
-cross-compiling, the value @var{cross-size} is used if given, otherwise
-@code{configure} exits with an error message.
+Define @code{SIZEOF_@var{type}} (@pxref{Standard Symbols}) to be the
+size in bytes of @var{type}. If @samp{type} is unknown, it gets a size
+of 0. If no @var{includes} are specified, the default includes are used
+(@pxref{Default Includes}). If you provide @var{include}, make sure to
+include @file{stdio.h} which is required for this macro to run.
+
+If cross-compiling, the value @var{cross-size} is used if given,
+otherwise @code{configure} exits with an error message.
For example, the call
+
@example
AC_CHECK_SIZEOF(int *)
@end example
+
@noindent
defines @code{SIZEOF_INT_P} to be 8 on DEC Alpha AXP systems.
@end defmac
@example
#ifdef F77_FUNC
-# define FOOBAR_F77 F77_FUNC(foobar,FOOBAR)
+# define FOOBAR_F77 F77_FUNC(foobar,FOOBAR)
#endif
#ifdef __cplusplus
extern "C" /* prevent C++ name mangling */
restrict yourself to the lowest common denominator. Even @code{unset}
is not supported by all shells! Also, include a space after the
exclamation point in interpreter specifications, like this:
+
@example
#! /usr/bin/perl
@end example
+
+@noindent
If you omit the space before the path, then 4.2BSD based systems (such
as Sequent DYNIX) will ignore the line, because they interpret @samp{#! /}
as a 4-byte magic number.
it.
Another nonportable shell programming construction is
+
@example
@var{var}=$@{@var{var}:-@var{value}@}
@end example
+
@noindent
The intent is to set @var{var} to @var{value} only if it is not already
set, but if @var{var} has any value, even the empty string, to leave it
alone. Old BSD shells, including the Ultrix @code{sh}, don't accept
the colon, and complain and die. A portable equivalent is
+
@example
: $@{@var{var}=@var{value}@}
@end example
Here is an example that uses the shell variable @code{fstype} to keep
track of whether the remaining cases need to be checked.
-@c FIXME: I hate this example, because it does not use the quotes
-@c properly, but it would be terrible to use quotes here. So? Should
-@c I just shut up, or advocate the right uses of (useless) quotes?
@example
@group
AC_MSG_CHECKING(how to get file system type)
fstype=no
# The order of these tests is important.
AC_TRY_CPP([#include <sys/statvfs.h>
-#include <sys/fstyp.h>], AC_DEFINE(FSTYPE_STATVFS) fstype=SVR4)
+#include <sys/fstyp.h>], [AC_DEFINE(FSTYPE_STATVFS) fstype=SVR4])
if test $fstype = no; then
-AC_TRY_CPP([#include <sys/statfs.h>
-#include <sys/fstyp.h>], AC_DEFINE(FSTYPE_USG_STATFS) fstype=SVR3)
+ AC_TRY_CPP([#include <sys/statfs.h>
+#include <sys/fstyp.h>], [AC_DEFINE(FSTYPE_USG_STATFS) fstype=SVR3])
fi
if test $fstype = no; then
-AC_TRY_CPP([#include <sys/statfs.h>
-#include <sys/vmount.h>], AC_DEFINE(FSTYPE_AIX_STATFS) fstype=AIX)
+ AC_TRY_CPP([#include <sys/statfs.h>
+#include <sys/vmount.h>], [AC_DEFINE(FSTYPE_AIX_STATFS) fstype=AIX])
fi
# (more cases omitted here)
AC_MSG_RESULT($fstype)
@example
AC_CHECK_FUNC(vprintf, [AC_DEFINE(HAVE_VPRINTF)])
if test "$ac_cv_func_vprintf" != yes; then
-AC_CHECK_FUNC(_doprnt, [AC_DEFINE(HAVE_DOPRNT)])
+ AC_CHECK_FUNC(_doprnt, [AC_DEFINE(HAVE_DOPRNT)])
fi
@end example
anything, they disable quoting entirely instead by setting the quote
characters to empty strings.) Here is an example:
+@c FIXME: Oh no, please, no, not that crap again. Well, a new section
+@c on quoting is needed since below the bad thing is advocated.
@example
AC_TRY_LINK(
changequote(<<, >>)dnl
projects / thirdparty / autoconf.git / commitdiff
