AC_PREREQ(2.65)
dnl Note this is parsed by (at least) make-dist and lisp/cedet/ede/emacs.el.
-AC_INIT(GNU Emacs, 25.0.92, bug-gnu-emacs@gnu.org)
+AC_INIT(GNU Emacs, 25.1.50, bug-gnu-emacs@gnu.org)
dnl Set emacs_config_options to the options of 'configure', quoted for the shell,
dnl and then quoted again for a C string. Separate options with spaces.
OPTION_DEFAULT_ON([gif],[don't compile with GIF image support])
OPTION_DEFAULT_ON([png],[don't compile with PNG image support])
OPTION_DEFAULT_ON([rsvg],[don't compile with SVG image support])
+OPTION_DEFAULT_ON([libsystemd],[don't compile with libsystemd support])
OPTION_DEFAULT_OFF([cairo],[compile with Cairo drawing (experimental)])
OPTION_DEFAULT_ON([xml2],[don't compile with XML parsing support])
OPTION_DEFAULT_ON([imagemagick],[don't compile with ImageMagick image support])
[Show Gtk+/Gdk deprecation warnings for Gtk+ >= 3.0])],
[ac_enable_gtk_deprecation_warnings="${enableval}"],[])
+BUILD_DETAILS=
+AC_ARG_ENABLE([build-details],
+ [AS_HELP_STRING([--disable-build-details],
+ [Make the build more deterministic by omitting host
+ names, time stamps, etc. from the output.])],
+ [test "$enableval" = no && BUILD_DETAILS=--no-build-details])
+AC_SUBST([BUILD_DETAILS])
+
dnl This used to use changequote, but, apart from 'changequote is evil'
dnl per the autoconf manual, we can speed up autoconf somewhat by quoting
dnl the great gob of text. Thus it's not processed for possible expansion.
* ) unported=yes ;;
esac
opsys=darwin
- ## Use fink packages if available.
- ## FIXME find a better way to do this: http://debbugs.gnu.org/11507
-## if test -d /sw/include && test -d /sw/lib; then
-## GCC_TEST_OPTIONS="-I/sw/include -L/sw/lib"
-## NON_GCC_TEST_OPTIONS=${GCC_TEST_OPTIONS}
-## fi
+ ## FIXME: Find a way to use Fink if available (Bug#11507).
;;
## Chromium Native Client
opsys=aix4-2
;;
- ## Silicon Graphics machines
- ## Iris 4D
- mips-sgi-irix6.5 )
- opsys=irix6-5
- # Without defining _LANGUAGE_C, things get masked out in the headers
- # so that, for instance, grepping for 'free' in stdlib.h fails and
- # AC_HEADER_STD_C fails. (MIPSPro 7.2.1.2m compilers, Irix 6.5.3m).
- NON_GCC_TEST_OPTIONS="-D_LANGUAGE_C"
- ;;
-
## Suns
*-sun-solaris* \
| i[3456]86-*-solaris2* | i[3456]86-*-sunos5* \
if test x$GCC = xyes; then
test "x$GCC_TEST_OPTIONS" != x && CC="$CC $GCC_TEST_OPTIONS"
-else
- test "x$NON_GCC_TEST_OPTIONS" != x && CC="$CC $NON_GCC_TEST_OPTIONS"
fi
dnl This is used in lib/Makefile.am to use nt/gnulib.mk, the
esac
fi
+# gl_GCC_VERSION_IFELSE([major], [minor], [run-if-found], [run-if-not-found])
+# ---------------------------------------------------------------------------
+# If $CPP is gcc-MAJOR.MINOR or newer, then run RUN-IF-FOUND.
+# Otherwise, run RUN-IF-NOT-FOUND.
+AC_DEFUN([gl_GCC_VERSION_IFELSE],
+ [AC_PREPROC_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[
+#if ($1) < __GNUC__ || (($1) == __GNUC__ && ($2) <= __GNUC_MINOR__)
+/* ok */
+#else
+# error "your version of gcc is older than $1.$2"
+#endif
+ ]]),
+ ], [$3], [$4])
+ ]
+)
+
AC_ARG_ENABLE([gcc-warnings],
- [AS_HELP_STRING([--enable-gcc-warnings],
- [turn on lots of GCC warnings/errors. This is intended for
- developers, and may generate false alarms when used
- with older or non-GNU development tools.])],
+ [AS_HELP_STRING([--enable-gcc-warnings@<:@=TYPE@:>@],
+ [control generation of GCC warnings. The TYPE 'yes'
+ means to fail if any warnings are issued; 'warn-only'
+ means issue warnings without failing (default for
+ developer builds); 'no' means disable warnings
+ (default for non-developer builds).])],
[case $enableval in
- yes|no) ;;
+ yes|no|warn-only) ;;
*) AC_MSG_ERROR([bad value $enableval for gcc-warnings option]) ;;
esac
gl_gcc_warnings=$enableval],
- [gl_gcc_warnings=no]
+ [# By default, use 'warn-only' if it looks like the invoker of 'configure'
+ # is a developer as opposed to a builder. This is most likely true
+ # if GCC is recent enough and there is a .git directory or file;
+ # however, if there is also a .tarball-version file it is probably
+ # just a release imported into Git for patch management.
+ gl_gcc_warnings=no
+ test -e "$srcdir"/.git && test ! -f "$srcdir"/.tarball-version &&
+ gl_GCC_VERSION_IFELSE([5], [3], [gl_gcc_warnings=warn-only])]
)
# clang is unduly picky about some things.
# When compiling with GCC, prefer -isystem to -I when including system
# include files, to avoid generating useless diagnostics for the files.
-AS_IF([test "$gl_gcc_warnings" != yes],
+AS_IF([test $gl_gcc_warnings = no],
[
isystem='-I'
AS_IF([test "$emacs_cv_clang" = yes],
nw="$nw -Wwrite-strings"
;;
esac
- AS_IF([test -z "$nw"],
+ AS_IF([test $gl_gcc_warnings = yes],
[gl_WARN_ADD([-Werror], [WERROR_CFLAGS])])
AC_SUBST([WERROR_CFLAGS])
nw="$nw -Wvla" # Emacs uses <vla.h>.
nw="$nw -Wswitch-default" # Too many warnings for now
nw="$nw -Winline" # OK to ignore 'inline'
- nw="$nw -Wjump-misses-init" # We sometimes safely jump over init.
nw="$nw -Wstrict-overflow" # OK to optimize assuming that
# signed overflow has undefined behavior
nw="$nw -Wsync-nand" # irrelevant here, and provokes ObjC warning
dnl We need -znocombreloc if we're using a relatively recent GNU ld.
dnl If we can link with the flag, it shouldn't do any harm anyhow.
-dnl (Don't use '-z nocombreloc' as -z takes no arg on Irix.)
dnl Treat GCC specially since it just gives a non-fatal 'unrecognized option'
dnl if not built to support GNU ld.
dnl Current possibilities handled by sed (aix4-2 -> aix,
dnl gnu-linux -> gnu/linux, etc.):
-dnl gnu, gnu/linux, gnu/kfreebsd, aix, cygwin, darwin, hpux, irix.
+dnl gnu, gnu/linux, gnu/kfreebsd, aix, cygwin, darwin, hpux.
dnl And special cases: berkeley-unix, usg-unix-v, ms-dos, windows-nt.
SYSTEM_TYPE=`echo $opsys | sed -e 's/[[0-9]].*//' -e 's|-|/|'`
dnl checks for header files
AC_CHECK_HEADERS_ONCE(
+ malloc.h
sys/systeminfo.h
sys/sysinfo.h
coff.h pty.h
## $window_system is now set to the window system we will
## ultimately use.
-if test "$window_system" = none && test "$gl_gcc_warnings" = yes; then
- # Too many warnings for now.
- nw=
- nw="$nw -Wsuggest-attribute=noreturn"
- gl_MANYWARN_COMPLEMENT([WARN_CFLAGS], [$WARN_CFLAGS], [$nw])
-
- gl_WARN_ADD([-Wno-unused-variable])
- gl_WARN_ADD([-Wno-unused-but-set-variable])
- gl_WARN_ADD([-Wno-unused-but-set-parameter])
-fi
-
term_header=
HAVE_X_WINDOWS=no
HAVE_X11=no
cygwin) hybrid_malloc=yes;;
esac
+if test "${system_malloc}" != yes && test "${doug_lea_malloc}" != yes \
+ && test "${UNEXEC_OBJ}" = unexelf.o; then
+ hybrid_malloc=yes
+fi
+
GMALLOC_OBJ=
+HYBRID_MALLOC=
if test "${system_malloc}" = "yes"; then
AC_DEFINE([SYSTEM_MALLOC], 1,
[Define to 1 to use the system memory allocator, even if it is not
elif test "$hybrid_malloc" = yes; then
AC_DEFINE(HYBRID_MALLOC, 1,
[Define to use gmalloc before dumping and the system malloc after.])
+ HYBRID_MALLOC=1
GNU_MALLOC=
GNU_MALLOC_reason="only before dumping"
GMALLOC_OBJ=gmalloc.o
of the main data segment.])
fi
fi
+AC_SUBST([HYBRID_MALLOC])
+AM_CONDITIONAL([HYBRID_MALLOC_LIB], [test -n "$HYBRID_MALLOC"])
AC_SUBST(GMALLOC_OBJ)
AC_SUBST(VMLIMIT_OBJ)
-if test "$doug_lea_malloc" = "yes" ; then
+if test "$doug_lea_malloc" = "yes" && test "$hybrid_malloc" != yes; then
if test "$GNU_MALLOC" = yes ; then
GNU_MALLOC_reason="
(Using Doug Lea's new malloc from the GNU C Library.)"
use_mmap_for_buffers=no
case "$opsys" in
- cygwin|mingw32|freebsd|irix6-5) use_mmap_for_buffers=yes ;;
+ cygwin|mingw32) use_mmap_for_buffers=yes ;;
esac
AC_FUNC_MMAP
OLD_LIBS=$LIBS
CFLAGS="$CFLAGS $IMAGEMAGICK_CFLAGS"
LIBS="$IMAGEMAGICK_LIBS $LIBS"
- AC_CHECK_FUNCS(MagickExportImagePixels MagickMergeImageLayers)
+ AC_CHECK_FUNCS(MagickExportImagePixels MagickMergeImageLayers MagickAutoOrientImage)
CFLAGS=$OLD_CFLAGS
LIBS=$OLD_LIBS
fi
fi
fi
+AC_CHECK_LIB(anl, getaddrinfo_a, HAVE_GETADDRINFO_A=yes)
+if test "${HAVE_GETADDRINFO_A}" = "yes"; then
+ AC_DEFINE(HAVE_GETADDRINFO_A, 1,
+[Define to 1 if you have getaddrinfo_a for asynchronous DNS resolution.])
+ GETADDRINFO_A_LIBS="-lanl"
+ AC_SUBST(GETADDRINFO_A_LIBS)
+fi
HAVE_GTK=no
GTK_OBJ=
AC_SUBST(LIBGNUTLS_LIBS)
AC_SUBST(LIBGNUTLS_CFLAGS)
+HAVE_LIBSYSTEMD=no
+if test "${with_libsystemd}" = "yes" ; then
+ dnl This code has been tested with libsystemd 222 and later.
+ dnl FIXME: Find the earliest version number for which Emacs should work,
+ dnl and change '222' to that number.
+ EMACS_CHECK_MODULES([LIBSYSTEMD], [libsystemd >= 222],
+ [HAVE_LIBSYSTEMD=yes], [HAVE_LIBSYSTEMD=no])
+ if test "${HAVE_LIBSYSTEMD}" = "yes"; then
+ AC_DEFINE(HAVE_LIBSYSTEMD, 1, [Define if using libsystemd.])
+ fi
+fi
+
+AC_SUBST(LIBSYSTEMD_LIBS)
+AC_SUBST(LIBSYSTEMD_CFLAGS)
+
NOTIFY_OBJ=
NOTIFY_SUMMARY=no
MODULES_OBJ=
MODULES_SUFFIX=
if test "${with_modules}" != "no"; then
- if test "$opsys" = "gnu-linux"; then
- LIBMODULES="-ldl"
- MODULES_SUFFIX=".so"
- HAVE_MODULES=yes
- elif test "$opsys" = "cygwin"; then
- MODULES_SUFFIX=".dll"
- HAVE_MODULES=yes
- elif test "$opsys" = "darwin"; then
- MODULES_SUFFIX=".so"
- HAVE_MODULES=yes
- elif test "$opsys" = "mingw32"; then
- MODULES_SUFFIX=".dll"
- HAVE_MODULES=yes
- else
- # BSD system have dlopen in the libc
- AC_CHECK_FUNC(dlopen, [MODULES_SUFFIX=".so"]
- [HAVE_MODULES=yes], [])
- fi
+ case $opsys in
+ gnu|gnu-linux)
+ LIBMODULES="-ldl"
+ MODULES_SUFFIX=".so"
+ HAVE_MODULES=yes
+ ;;
+ cygwin|mingw32)
+ MODULES_SUFFIX=".dll"
+ HAVE_MODULES=yes
+ ;;
+ darwin)
+ MODULES_SUFFIX=".so"
+ HAVE_MODULES=yes
+ ;;
+ *)
+ # BSD system have dlopen in the libc
+ AC_CHECK_FUNC(dlopen, [MODULES_SUFFIX=".so"]
+ [HAVE_MODULES=yes], [])
+ ;;
+ esac
if test "${HAVE_MODULES}" = no; then
AC_MSG_ERROR([Dynamic modules are not supported on your system])
AC_SUBST(LIBXML2_LIBS)
AC_SUBST(LIBXML2_CFLAGS)
-# If netdb.h doesn't declare h_errno, we must declare it by hand.
-# On MinGW, that is provided by nt/inc/sys/socket.h and w32.c.
-if test "${opsys}" = "mingw32"; then
- emacs_cv_netdb_declares_h_errno=yes
-fi
-AC_CACHE_CHECK(whether netdb declares h_errno,
- emacs_cv_netdb_declares_h_errno,
-[AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <netdb.h>]],
- [[return h_errno;]])],
- emacs_cv_netdb_declares_h_errno=yes, emacs_cv_netdb_declares_h_errno=no)])
-if test $emacs_cv_netdb_declares_h_errno = yes; then
- AC_DEFINE(HAVE_H_ERRNO, 1, [Define to 1 if netdb.h declares h_errno.])
-fi
-
# Check for mail-locking functions in a "mail" library. Probably this should
# have the same check as for liblockfile below.
AC_CHECK_LIB(mail, maillock, have_mail=yes, have_mail=no)
case "$opsys" in
aix4-2) mail_lock="lockf" ;;
- gnu|freebsd|dragonfly|netbsd|openbsd|darwin|irix6-5) mail_lock="flock" ;;
+ gnu|freebsd|dragonfly|netbsd|openbsd|darwin) mail_lock="flock" ;;
## On GNU/Linux systems, both methods are used by various mail programs.
## I assume most people are using newer mailers that have heard of flock.
getrusage get_current_dir_name \
lrand48 random rint \
select getpagesize setlocale newlocale \
-getrlimit setrlimit shutdown getaddrinfo \
+getrlimit setrlimit shutdown \
pthread_sigmask strsignal setitimer \
sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \
gai_strerror sync \
dnl No need to check for posix_memalign if aligned_alloc works.
AC_CHECK_FUNCS([aligned_alloc posix_memalign], [break])
+AC_CHECK_DECLS([aligned_alloc], [], [], [[#include <stdlib.h>]])
dnl Cannot use AC_CHECK_FUNCS
AC_CACHE_CHECK([for __builtin_unwind_init],
[emacs_cv_alternate_stack=yes],
[emacs_cv_alternate_stack=no])])
-# Do we have res_init, for detecting changes in /etc/resolv.conf?
-# On Darwin, res_init appears not to be useful: see bug#562 and
-# http://lists.gnu.org/archive/html/emacs-devel/2007-11/msg01467.html
-resolv=no
-
-if test $opsys != darwin; then
-
- AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <netinet/in.h>
-#include <arpa/nameser.h>
-#include <resolv.h>]],
- [[return res_init();]])],
- have_res_init=yes, have_res_init=no)
- if test "$have_res_init" = no; then
- OLIBS="$LIBS"
- LIBS="$LIBS -lresolv"
- AC_MSG_CHECKING(for res_init with -lresolv)
- AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <netinet/in.h>
-#include <arpa/nameser.h>
-#include <resolv.h>]],
- [[return res_init();]])],
- have_res_init=yes, have_res_init=no)
- AC_MSG_RESULT($have_res_init)
- if test "$have_res_init" = yes ; then
- resolv=yes
- fi
- LIBS="$OLIBS"
- fi
-
- if test "$have_res_init" = yes; then
- AC_DEFINE(HAVE_RES_INIT, 1, [Define to 1 if res_init is available.])
- fi
-fi dnl !darwin
-
# Do we need the Hesiod library to provide the support routines?
dnl FIXME? Should we be skipping this on Darwin too?
LIBHESIOD=
+LIBRESOLV=
if test "$with_hesiod" != no ; then
# Don't set $LIBS here -- see comments above. FIXME which comments?
+ resolv=no
AC_CHECK_FUNC(res_send, , [AC_CHECK_FUNC(__res_send, ,
[AC_CHECK_LIB(resolv, res_send, resolv=yes,
[AC_CHECK_LIB(resolv, __res_send, resolv=yes)])])])
else
RESOLVLIB=
fi
+ hesiod=no
AC_CHECK_FUNC(hes_getmailhost, , [AC_CHECK_LIB(hesiod, hes_getmailhost,
hesiod=yes, :, $RESOLVLIB)])
if test x"$hesiod" = xyes; then
LIBHESIOD=-lhesiod
+ LIBRESOLV=$RESOLVLIB
fi
fi
AC_SUBST(LIBHESIOD)
-
-# Do we need libresolv (due to res_init or Hesiod)?
-if test "$resolv" = yes && test $opsys != darwin; then
- LIBRESOLV=-lresolv
-else
- LIBRESOLV=
-fi
AC_SUBST(LIBRESOLV)
# These tell us which Kerberos-related libraries to use.
SEPCHAR=':'
fi
AC_DEFINE_UNQUOTED(SEPCHAR, ['$SEPCHAR'], [Character that separates PATH elements.])
-dnl This is for MinGW, and is used in test/automated/Makefile.in.
+dnl This is for MinGW, and is used in test/Makefile.in.
dnl The MSYS Bash has heuristics for replacing ':' with ';' when it
dnl decides that a command-line argument to be passed to a MinGW program
dnl is a PATH-style list of directories. But that heuristics plays it
case $opsys in
- irix6-5 | sol2* | unixware )
+ sol2* | unixware )
dnl Some SVr4s don't define NSIG in sys/signal.h for ANSI environments;
dnl instead, there's a system variable _sys_nsig. Unfortunately, we
dnl need the constant to dimension an array. So wire in the appropriate
case $opsys in
dnl SIGIO exists, but the feature doesn't work in the way Emacs needs.
dnl See eg <http://article.gmane.org/gmane.os.openbsd.ports/46831>.
- hpux* | irix6-5 | nacl | openbsd | sol2* | unixware )
+ hpux* | nacl | openbsd | sol2* | unixware )
emacs_broken_SIGIO=yes
;;
dnl NARROWPROTO, we will see the wrong function prototypes for X functions
dnl taking float or double parameters.
case $opsys in
- cygwin|gnu|gnu-linux|gnu-kfreebsd|irix6-5|freebsd|netbsd|openbsd)
+ cygwin|gnu|gnu-linux|gnu-kfreebsd|freebsd|netbsd|openbsd)
AC_DEFINE(NARROWPROTO, 1, [Define if system's imake configuration
file defines 'NeedWidePrototypes' as 'NO'.])
;;
dnl Used in process.c, this must be a loop, even if it only runs once.
-dnl (Except on SGI; see below. Take that, clarity and consistency!)
AH_TEMPLATE(PTY_ITERATION, [How to iterate over PTYs.])
dnl Only used if !PTY_ITERATION. Iterate from FIRST_PTY_LETTER to z,
dnl trying suffixes 0-16.
AC_DEFINE(PTY_TTY_NAME_SPRINTF, [sprintf (pty_name, "/dev/pty/tty%c%x", c, i);])
;;
- irix6-5 )
- dnl It looks like this cannot be right, because it is not a loop.
- dnl However, process.c actually does this:
- dnl # ifndef __sgi
- dnl continue;
- dnl # else
- dnl return -1;
- dnl # endif
- dnl which presumably makes it OK, since irix == sgi (?).
- dnl FIXME it seems like this special treatment is unnecessary?
- dnl Why can't irix use a single-trip loop like eg cygwin?
- AC_DEFINE(PTY_ITERATION, [])
- dnl Not used, because PTY_ITERATION is defined.
- AC_DEFINE(FIRST_PTY_LETTER, ['q'])
- AC_DEFINE(PTY_OPEN, [ { struct sigaction ocstat, cstat; struct stat stb; char * name; sigemptyset(&cstat.sa_mask); cstat.sa_handler = SIG_DFL; cstat.sa_flags = 0; sigaction(SIGCHLD, &cstat, &ocstat); name = _getpty (&fd, O_RDWR | O_NDELAY, 0600, 0); sigaction(SIGCHLD, &ocstat, (struct sigaction *)0); if (name == 0) return -1; if (fd < 0) return -1; if (fstat (fd, &stb) < 0) return -1; strcpy (pty_name, name); }])
- dnl No need to get the pty name at all.
- AC_DEFINE(PTY_NAME_SPRINTF, [])
- dnl No need to use sprintf to get the tty name--we get that from _getpty.
- AC_DEFINE(PTY_TTY_NAME_SPRINTF, [])
- ;;
-
sol2* )
dnl On SysVr4, grantpt(3) forks a subprocess, so do not use
dnl O_CLOEXEC when opening the pty, and keep the SIGCHLD handler
case $opsys in
dnl Perry Smith <pedz@ddivt1.austin.ibm.com> says this is correct for AIX.
- dnl thomas@mathematik.uni-bremen.de says this is needed for IRIX.
- aix4-2 | cygwin | gnu | irix6-5 | dragonfly | freebsd | netbsd | openbsd | darwin )
+ aix4-2 | cygwin | gnu | dragonfly | freebsd | netbsd | openbsd | darwin )
AC_DEFINE(SIGNALS_VIA_CHARACTERS, 1)
;;
AC_DEFINE(GC_SETJMP_WORKS, 1)
else
case $opsys in
- dnl irix: Tested on Irix 6.5. SCM worked on earlier versions.
- aix* | dragonfly | freebsd | netbsd | openbsd | irix6-5 | sol2* )
+ aix* | dragonfly | freebsd | netbsd | openbsd | sol2* )
AC_DEFINE(GC_SETJMP_WORKS, 1)
;;
esac
AC_DEFINE(HPUX, [], [Define if the system is HPUX.])
;;
- irix6-5)
- AC_DEFINE(USG, [])
- AC_DEFINE(USG5_4, [])
- AC_DEFINE(IRIX6_5, [], [Define if the system is IRIX.])
- ;;
-
mingw32)
AC_DEFINE(DOS_NT, [])
AC_DEFINE(WINDOWSNT, 1, [Define if compiling for native MS Windows.])
reopen it in the child.])
;;
- irix6-5)
- AC_DEFINE(PREFER_VSUSP, 1, [Define if process_send_signal should
- use VSUSP instead of VSWTCH.])
- ;;
-
sol2-10)
AC_DEFINE(_STRUCTURED_PROC, 1, [Needed for system_process_attributes
on Solaris.])
AC_SUBST(RALLOC_OBJ)
if test "$opsys" = "cygwin"; then
- CYGWIN_OBJ="sheap.o cygw32.o"
+ CYGWIN_OBJ="cygw32.o"
## Cygwin differs because of its unexec().
PRE_ALLOC_OBJ=
POST_ALLOC_OBJ=lastfile.o
leim/Makefile nextstep/Makefile nt/Makefile])
dnl test/ is not present in release tarfiles.
-opt_makefile=test/automated/Makefile
+opt_makefile=test/Makefile
if test -f "$srcdir/$opt_makefile.in"; then
SUBDIR_MAKEFILES="$SUBDIR_MAKEFILES $opt_makefile"
dnl Again, it's best not to use a variable. Though you can add
dnl ", [], [opt_makefile='$opt_makefile']" and it should work.
- AC_CONFIG_FILES([test/automated/Makefile])
+ AC_CONFIG_FILES([test/Makefile])
fi
children.
@end defun
+@defun window-pixel-height-before-size-change &optional Lisp_Object &optional window
+This function returns the height of window @var{window} in pixels at the
+time @code{window-size-change-functions} was run for the last time on
+@var{window}'s frame (@pxref{Window Hooks}).
+@end defun
+
@cindex window pixel width
@cindex pixel width of a window
@cindex total pixel width of a window
the screen areas spanned by its children.
@end defun
+@defun window-pixel-width-before-size-change &optional Lisp_Object &optional window
+This function returns the width of window @var{window} in pixels at the
+time @code{window-size-change-functions} was run for the last time on
+@var{window}'s frame (@pxref{Window Hooks}).
+@end defun
+
@cindex full-width window
@cindex full-height window
The following functions can be used to determine whether a given
@cindex body width of a window
The @dfn{body width} of a window is the width of its text area, which
does not include the scroll bar, fringes, margins or a right divider.
+ Note that when one or both fringes are removed (by setting their width
+ to zero), the display engine reserves two character cells, one on each
+ side of the window, for displaying the continuation and truncation
+ glyphs, which leaves 2 columns less for text display. (The function
+ @code{window-max-chars-per-line}, described below, takes this
+ peculiarity into account.)
@defun window-body-width &optional window pixelwise
This function returns the width, in columns, of the body of window
entry (@pxref{Choosing Window Options}), raises that frame if necessary.
@end defun
+@defun display-buffer-reuse-mode-window buffer alist
+This function tries to display @var{buffer} by finding a window
+that is displaying a buffer in a given mode.
+
+If @var{alist} contains a @code{mode} entry, its value is a major mode
+(a symbol) or a list of major modes. If @var{alist} contains no
+@code{mode} entry, the current major mode of @var{buffer} is used. A
+window is a candidate if it displays a buffer that derives from one of
+the given modes.
+
+The behaviour is also controlled by entries for
+@code{inhibit-same-window}, @code{reusable-frames} and
+@code{inhibit-switch-frame} as is done in the function
+@code{display-buffer-reuse-window}.
+
+@end defun
+
@defun display-buffer-pop-up-frame buffer alist
This function creates a new frame, and displays the buffer in that
frame's window. It actually performs the frame creation by calling
The argument @var{configuration} must be a value that was previously
returned by @code{current-window-configuration}. The configuration is
restored in the frame from which @var{configuration} was made, whether
-that frame is selected or not. This always counts as a window size
-change and triggers execution of the @code{window-size-change-functions}
-(@pxref{Window Hooks}), because @code{set-window-configuration} doesn't
-know how to tell whether the new configuration actually differs from the
-old one.
+that frame is selected or not. In some rare cases this may trigger
+execution of the @code{window-size-change-functions} (@pxref{Window
+Hooks}) even if the size of windows did not change at all. The
+@code{window-configuration-change-hook} functions will be called if and
+only if at least one window was added to or deleted from the frame.
If the frame from which @var{configuration} was saved is dead, all this
function does is restore the three variables @code{window-min-height},
@end defvar
@defvar window-size-change-functions
-This variable holds a list of functions to be called if the size of
-any window changes for any reason. The functions are called at the
-beginning of a redisplay cycle, and just once for each frame on which
-size changes have occurred.
-
-Each function receives the frame as its sole argument. There is no
-direct way to find out which windows on that frame have changed size, or
-precisely how. However, if a size-change function records, at each
-call, the existing windows and their sizes, it can also compare the
-present sizes and the previous sizes.
-
-Creating or deleting windows counts as a size change, and therefore
-causes these functions to be called. Changing the frame size also
-counts, because it changes the sizes of the existing windows.
+This variable holds a list of functions to be called if the size of any
+window changes for any reason. The functions are called once per
+redisplay, and once for each frame on which size changes have occurred.
+
+Each function receives the frame as its sole argument. To find out
+whether a specific window has changed size, compare the return values of
+@code{window-pixel-width-before-size-change} and
+@code{window-pixel-width} respectively
+@code{window-pixel-height-before-size-change} and
+@code{window-pixel-height} for that window (@pxref{Window Sizes}).
+
+These function are usually only called when at least one window was
+added or has changed size since the last time this hook was run for the
+associated frame. In some rare cases this hook also runs when a window
+that was added intermittently has been deleted afterwards. In these
+cases none of the windows on the frame will appear to have changed its
+size.
You may use @code{save-selected-window} in these functions
(@pxref{Selecting Windows}). However, do not use
@code{save-window-excursion} (@pxref{Window Configurations}); exiting
-that macro counts as a size change, which would cause these functions
-to be called over and over.
+that macro counts as a size change, which would cause these functions to
+be called again.
@end defvar
@defvar window-configuration-change-hook
-A normal hook that is run every time you change the window configuration
-of an existing frame. This includes splitting or deleting windows,
-changing the sizes of windows, or displaying a different buffer in a
-window.
+A normal hook that is run every time the window configuration of a frame
+changes. Window configuration changes include splitting and deleting
+windows and the display of a different buffer in a window. Resizing the
+frame or individual windows do not count as configuration changes. Use
+@code{window-size-change-functions}, see above, when you want to track
+size changes that are not caused by the deletion or creation of windows.
The buffer-local part of this hook is run once for each window on the
affected frame, with the relevant window selected and its buffer