@cindex Back trace
@cindex Macro invocation stack
-@command{autoconf} displays a back trace for errors, but not for
-warnings; if you want them, just pass @option{-W error}. For instance,
-on this @file{configure.ac}:
-
-@example
-AC_DEFUN([INNER],
-[AC_TRY_RUN([exit (0)])])
-
-AC_DEFUN([OUTER],
-[INNER])
-
-AC_INIT
-OUTER
-@end example
-
-@noindent
-you get:
-
-@example
-$ @kbd{autoconf -Wcross}
-configure.ac:8: warning: AC_TRY_RUN called without default \
-to allow cross compiling
-$ @kbd{autoconf -Wcross,error}
-configure.ac:8: error: AC_TRY_RUN called without default \
-to allow cross compiling
-acgeneral.m4:3044: AC_TRY_RUN is expanded from...
-configure.ac:2: INNER is expanded from...
-configure.ac:5: OUTER is expanded from...
-configure.ac:8: the top level
-@end example
+Because @command{autoconf} uses @command{autom4te} behind the scenes, it
+displays a back trace for errors, but not for warnings; if you want
+them, just pass @option{-W error}. @xref{Invoking autom4te}, for some
+examples.
@item --trace=@var{macro}[:@var{format}]
@itemx -t @var{macro}[:@var{format}]
The @var{format} is a regular string, with newlines if desired, and
several special escape codes. It defaults to @samp{$f:$l:$n:$%}; see
-below for details on the @var{format}.
+@ref{Invoking autom4te}, for details on the @var{format}.
@item --initialization
@itemx -i
It is often necessary to check the content of a @file{configure.ac}
file, but parsing it yourself is extremely fragile and error-prone. It
is suggested that you rely upon @option{--trace} to scan
-@file{configure.ac}.
-
-The @var{format} of @option{--trace} can use the following special
-escapes:
-
-@table @samp
-@item $$
-The character @samp{$}.
-
-@item $f
-The filename from which @var{macro} is called.
-
-@item $l
-The line number from which @var{macro} is called.
-
-@item $d
-The depth of the @var{macro} call. This is an M4 technical detail that
-you probably don't want to know about.
-
-@item $n
-The name of the @var{macro}.
-
-@item $@var{num}
-The @var{num}th argument of the call to @var{macro}.
-
-@item $@@
-@itemx $@var{sep}@@
-@itemx $@{@var{separator}@}@@
-All the arguments passed to @var{macro}, separated by the character
-@var{sep} or the string @var{separator} (@samp{,} by default). Each
-argument is quoted, i.e., enclosed in a pair of square brackets.
-
-@item $*
-@itemx $@var{sep}*
-@itemx $@{@var{separator}@}*
-As above, but the arguments are not quoted.
-
-@item $%
-@itemx $@var{sep}%
-@itemx $@{@var{separator}@}%
-As above, but the arguments are not quoted, all new line characters in
-the arguments are smashed, and the default separator is @samp{:}.
-
-The escape @samp{$%} produces single-line trace outputs (unless you put
-newlines in the @samp{separator}), while @samp{$@@} and @samp{$*} do
-not.
-@end table
-
-For instance, to find the list of variables that are substituted, use:
+@file{configure.ac}. For instance, to find the list of variables that
+are substituted, use:
@example
@group
@defmac AC_SEARCH_LIBS (@var{function}, @var{search-libs}, @ovar{action-if-found}, @ovar{action-if-not-found}, @ovar{other-libraries})
@acindex SEARCH_LIBS
Search for a library defining @var{function} if it's not already
-available. This equates to calling @code{AC_TRY_LINK_FUNC} first
-with no libraries, then for each library listed in @var{search-libs}.
+available. This equates to calling
+@samp{AC_LINK_IFELSE([AC_LANG_CALL([@var{function}])])} first with no
+libraries, then for each library listed in @var{search-libs}.
Add @option{-l@var{library}} to @code{LIBS} for the first library found
to contain @var{function}, and run @var{action-if-found}. If the
The following macros check for C compiler or machine architecture
features. To check for characteristics not listed here, use
@code{AC_COMPILE_IFELSE} (@pxref{Running the Compiler}) or
-@code{AC_TRY_RUN} (@pxref{Run Time})
+@code{AC_RUN_IFELSE} (@pxref{Run Time}).
@defmac AC_C_BACKSLASH_A
@acindex HAVE_C_BACKSLASH_A
The following macros check for Fortran 77 compiler characteristics. To
check for characteristics not listed here, use @code{AC_COMPILE_IFELSE}
-(@pxref{Running the Compiler}) or @code{AC_TRY_RUN} (@pxref{Run Time}),
-making sure to first set the current language to Fortran 77
+(@pxref{Running the Compiler}) or @code{AC_RUN_IFELSE} (@pxref{Run
+Time}), making sure to first set the current language to Fortran 77
@code{AC_LANG(Fortran 77)} (@pxref{Language Choice}).
If you really need to test for a run-time behavior while configuring,
you can write a test program to determine the result, and compile and
-run it using @code{AC_TRY_RUN}. Avoid running test programs if
+run it using @code{AC_RUN_IFELSE}. Avoid running test programs if
possible, because this prevents people from configuring your package for
cross-compiling.
-@defmac AC_TRY_RUN (@var{program}, @ovar{action-if-true}, @ovar{action-if-false}, @ovar{action-if-cross-compiling})
-@acindex TRY_RUN
+@defmac AC_RUN_IFELSE (@var{input}, @ovar{action-if-found}, @ovar{action-if-not-found}, @ovar{action-if-cross-compiling})
+@acindex RUN_IFELSE
If @var{program} compiles and links successfully and returns an exit
status of 0 when executed, run shell commands @var{action-if-true}.
Otherwise, run shell commands @var{action-if-false}.
-This macro double quotes @var{program}, the text of a program in the
-current language (@pxref{Language Choice}), on which shell variable and
-back quote substitutions are performed. This macro uses @code{CFLAGS}
-or @code{CXXFLAGS}, @code{CPPFLAGS}, @code{LDFLAGS}, and @code{LIBS}
-when compiling.
+The @var{input} can be made by @code{AC_LANG_PROGRAM} and friends. This
+macro uses @code{CFLAGS} or @code{CXXFLAGS}, @code{CPPFLAGS},
+@code{LDFLAGS}, and @code{LIBS}
-If the C compiler being used does not produce executables that run on
-the system where @command{configure} is being run, then the test program is
+If the compiler being used does not produce executables that run on the
+system where @command{configure} is being run, then the test program is
not run. If the optional shell commands @var{action-if-cross-compiling}
are given, they are run instead. Otherwise, @command{configure} prints
an error message and exits.
Try to provide a pessimistic default value to use when cross-compiling
makes run-time tests impossible. You do this by passing the optional
-last argument to @code{AC_TRY_RUN}. @command{autoconf} prints a warning
-message when creating @command{configure} each time it encounters a call to
-@code{AC_TRY_RUN} with no @var{action-if-cross-compiling} argument
-given. You may ignore the warning, though users will not be able to
-configure your package for cross-compiling. A few of the macros
-distributed with Autoconf produce this warning message.
+last argument to @code{AC_RUN_IFELSE}. @command{autoconf} prints a
+warning message when creating @command{configure} each time it
+encounters a call to @code{AC_RUN_IFELSE} with no
+@var{action-if-cross-compiling} argument given. You may ignore the
+warning, though users will not be able to configure your package for
+cross-compiling. A few of the macros distributed with Autoconf produce
+this warning message.
To configure for cross-compiling you can also choose a value for those
parameters based on the canonical system name (@pxref{Manual
Configuration}). Alternatively, set up a test results cache file with
the correct values for the host system (@pxref{Caching Results}).
-To provide a default for calls of @code{AC_TRY_RUN} that are embedded in
-other macros, including a few of the ones that come with Autoconf, you
-can call @code{AC_PROG_CC} before running them. Then, if the shell
-variable @code{cross_compiling} is set to @samp{yes}, use an alternate
-method to get the results instead of calling the macros.
-
+To provide a default for calls of @code{AC_RUN_IFELSE} that are embedded
+in other macros, including a few of the ones that come with Autoconf,
+you can test whether the shell variable @code{cross_compiling} is set to
+@samp{yes}, and then use an alternate method to get the results instead
+of calling the macros.
@node Systemology
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])
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/statvfs.h>
+#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_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/statfs.h>
+#include <sys/fstyp.h>]])],
+ [AC_DEFINE(FSTYPE_USG_STATFS) fstype=SVR3])
fi
if test $fstype = no; then
- AC_TRY_CPP([#include <sys/statfs.h>
-#include <sys/vmount.h>],
- [AC_DEFINE(FSTYPE_AIX_STATFS) fstype=AIX])
+ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/statfs.h>
+#include <sys/vmount.h>]])]),
+ [AC_DEFINE(FSTYPE_AIX_STATFS) fstype=AIX])
fi
# (more cases omitted here)
AC_MSG_RESULT([$fstype])
@example
AC_DEFUN([INNER],
-[AC_TRY_RUN([exit (0)])])
+[AC_RUN_IFELSE([AC_LANG_PROGRAM([exit (0)])])])
AC_DEFUN([OUTER],
[INNER])
@example
$ @kbd{autom4te -l autoconf -Wcross}
-configure.ac:8: warning: AC_TRY_RUN called without default \
+configure.ac:8: warning: AC_RUN_IFELSE called without default \
to allow cross compiling
-$ @kbd{autom4te -l autoconf -Wcross,error}
-configure.ac:8: error: AC_TRY_RUN called without default \
+$ @kbd{autom4te -l autoconf -Wcross,error -f}
+configure.ac:8: error: AC_RUN_IFELSE called without default \
to allow cross compiling
-acgeneral.m4:3044: AC_TRY_RUN is expanded from...
+acgeneral.m4:3044: AC_RUN_IFELSE is expanded from...
configure.ac:2: INNER is expanded from...
configure.ac:5: OUTER is expanded from...
configure.ac:8: the top level
@end example
+
@item --melt
@itemx -m
Do not use frozen files. Any argument @code{@var{file}.m4f} will be
[ac_cv_emxos2=no])])
@end example
-When using @code{AC_TRY_RUN} or any macro that cannot work when
+When using @code{AC_RUN_IFELSE} or any macro that cannot work when
cross-compiling, provide a pessimistic value (typically @samp{no}).
Feel free to use various tricks to prevent auxiliary tools, such as
@defmac AC_COMPILE_CHECK (@var{echo-text}, @var{includes}, @var{function-body}, @var{action-if-found}, @ovar{action-if-not-found})
@acindex COMPILE_CHECK
-This is an obsolete version of @code{AC_TRY_COMPILE} (@pxref{Running the
-Compiler}), with the addition that it prints @samp{checking for
-@var{echo-text}} to the standard output first, if @var{echo-text} is
-non-empty. Use @code{AC_MSG_CHECKING} and @code{AC_MSG_RESULT} instead
-to print messages (@pxref{Printing Messages}).
+This is an obsolete version of @code{AC_TRY_COMPILE} itself replaced by
+@code{AC_COMPILE_IFELSE} (@pxref{Running the Compiler}), with the
+addition that it prints @samp{checking for @var{echo-text}} to the
+standard output first, if @var{echo-text} is non-empty. Use
+@code{AC_MSG_CHECKING} and @code{AC_MSG_RESULT} instead to print
+messages (@pxref{Printing Messages}).
@end defmac
@defmac AC_CONST
@defmac AC_TEST_PROGRAM
@acindex TEST_PROGRAM
-@code{AC_TRY_RUN}
+@code{AC_TRY_RUN}, replaced with @code{AC_RUN_IFELSE}.
@end defmac
@defmac AC_TIMEZONE
[@var{action-if-false}])}.
@end defmac
+@defmac AC_TRY_RUN (@var{program}, @ovar{action-if-true}, @ovar{action-if-false}, @ovar{action-if-cross-compiling})
+@acindex TRY_RUN
+Same as @samp{AC_RUN_IFELSE([AC_LANG_SOURCE([[@var{program}]],
+[@var{action-if-true}], [@var{action-if-false}],
+[@var{action-if-cross-compiling}])} (@pxref{Run Time}).
+@end defmac
+
+
@defmac AC_UID_T
@acindex UID_T
@code{AC_TYPE_UID_T}
projects / thirdparty / autoconf.git / commitdiff
