Allow --with-dri-drivers={,no} to disable DRI drivers build.

Signed-off-by: Florent Thoumie <flz@FreeBSD.org>
Signed-off-by: Robert Noland <rnoland@2hip.net>

Add an --enable-motif option, which will enable the Motif widgets in
libGLw and link it with libXm. The Motif installation information will
be gathered from the motif-config script (this comes with LessTif) or
fallback to the standard autoconf checks.

To allow the location of the Motif headers to be set from configure, the
default setting of -I/usr/include/Motif1.2 has been moved into
configs/default and then passed to the Makefile through the MOTIF_CFLAGS
variable.

Establish the shell that make will use from configure. This is exactly
how autoconf/automake operate, with the environment variable
CONFIG_SHELL respected to override the autoconf checks. In the usual
case where the user just executes `./configure', autoconf will pick a
shell from the current shell, sh, bash, ksh or sh5 that meets its base
criteria.

The special Solaris case of looking for a POSIX shell has been changed
to just set the SHELL variable since autoconf substitutes this already.
The EXTRA_CONFIG_LINES substitution is dropped as it should no longer be
needed.

Try to tell the user that the --x-* options are only used when the X
libraries can't be found by pkg-config.

The documentation in autoconf.html is much more explicit about how the
different configure options control the build. This adds a notice at the
end of the `./configure --help' output to tell the user about it.

Explicitly allow the argument to --with-dri-drivers to contain
comma-separated or space-separated drivers. A space-separated driver
list worked by chance before.

Currently the installation directories for libraries and headers are
resolved within the install commands. For instance, the libraries will
be installed to $(INSTALL_DIR)/$(LIB_DIR). This limits the flexibility
of the installation, such as when the libraries should be installed to a
subdirectory like /usr/lib/tls.

This adds the make variables $(INSTALL_LIB_DIR) and $(INSTALL_INC_DIR)
to define the locations that the libraries and headers are installed.
For the static configs, this resolves exactly as before to
$(INSTALL_DIR)/include and $(INSTALL_DIR)/$(LIB_DIR). For autoconf, they
are derived directly from the --libdir and --includedir settings.

Improve the --with-dri-drivers help text so that users are aware that
they should install the swrast DRI driver.

Rather than just defining HAVE_POSIX_MEMALIGN on Linux, check whether
the function exists on all platforms and define the macro if it is.

Signed-off-by: Brian Paul <brian.paul@tungstengraphics.com>

The architecture- and platorm-specific settings were scattered
throughout the configure script. This moves them near the beginning
before any of the driver-specific settings.

I'll release a libdrm 2.3.1 without TTM apis included from a special
drm branch that should allow mesa 7.1 to build against it.

I've had to turn off DRI2 stuff.

Adds an --enable-xcb switch to use XCB in GLX. This only has an effect
when the driver is DRI.

Since the only valid consumer of the DRI drivers is the X.Org xserver,
this changes the default DRI driver directory to match xorg-server:
${libdir}/dri. The old default of /usr/X11R6/modules/dri was wrong for
nearly all current systems.

This commit adds an autoconf macro, MESA_PIC_FLAGS, which sets the
PIC flags according to platform and static/shared setting. The platform
specifics are taken straight from libtool.m4 and stripped down to just
the flags and platforms we cover in Mesa. This should hopefully make it
possible to use autoconf on non-GCC platforms.

The macro is added external to configure.ac in acinclude.m4 since it's
pretty bloated.

Note to BSDers: Previously, x86 defaulted to non-PIC on FreeBSD. I
didn't carry that preference into this macro. Instead, you can just use
--disable-pic where desired.

Minor tweak so that running config.status will entirely recreate the
configure settings by replacing the configs/current symlink.

Two fixes to the asm configuration:
 - Disable when the user is cross-compiling for x86 or x86_64 since it
   requires running an executable compiled for the target host.
 - If the user has specified --enable-32-bit on x86_64 or --enable-64-bit
   on x86, respect that and choose the correct asm architecture.

The DRI modules can only be built against libdrm master (currently
version 2.3.1), so this should be enforced to save people from trying to
build against older versions.

Added a section at the top of the script to consolidate all required
versions.

The variable no_x was being set to yes when libX11 was not found through
pkg-config. This causes AC_PATH_XTRA to skip its search for the X11
libraries, which was not the intended effect. Also switched to using the
PKG_CHECK_EXISTS autoconf macro.

Added the make script version.mk to print the various version numbers
from configs/default. This is used to substitute the version in autoconf
rather than duplicating it in both places.

based on patch by Dan Nicholson <dbn.lists@gmail.com>

Instead of postponing the error from missing pkg-config macros to when
configure is run, make autoconf exit by using m4 macros.

Since the autoconf config inherits from default, we don't need to
duplicate and substitute the MESA_* version numbers in configure.ac.
The version number is only needed in configure for the help text.

The autoconf macro AC_PATH_PROGS handles the case of searching for
multiple program names already, so we don't need to open code it. Also
changed the search to AC_CHECK_PROGS so that it doesn't set the full
path unless the user specified. Finally, report back the found value at
the end for what the user should run.

Add DRI2 direct rendering support to libGL and add DRI2 client side
protocol code.  Extend the GLX 1.3 create drawable functions in
glx_pbuffer.c to call into the DRI driver when possible.

Introduce __DRIconfig, opaque struct that represents a DRI driver
configuration.  Get's rid of the open coded __GLcontextModes in the
DRI driver interface and the context modes create and destroy
functions that the loader was requires to provide.  glcore.h is no
longer part of the DRI driver interface.  The DRI config is GL binding
agnostic, that is, not specific to GLX, EGL or other bindings.

The core API is now also an extension, and the driver exports a list
of extensions as the symbol __driDriverExtensions, which the loader
must dlsym() for.  The list of extension will always include the DRI
core extension, which allows creating and manipulating DRI screens,
drawables and contexts.  The DRI legacy extension, when available,
provides alternative entry points for creating the DRI objects that
work with the XF86DRI infrastructure.

Change DRI2 client code to not use drm drawables or contexts.  We
never used drm_drawable_t's and the only use for drm_context_t was as
a unique identifier when taking the lock.  We now just allocate a
unique lock ID out of the DRILock sarea block.  Once we get rid of the
lock entirely, we can drop this hack.

Change the interface between dri_util.c and the drivers, so that the
drivers now export the DriverAPI struct as driDriverAPI instead of the
InitScreen entry point.  This lets us avoid dlsym()'ing for the DRI2
init screen function to see if DRI2 is supported by the driver.

This logic was copied from the xserver.

Since the xdemos only link to libGL now, we can enable them for all but
the osmesa driver target.

Rather than constructing the GCC include path from `-print-search-dirs',
we can get the path directly from `-print-file-name=include'. This is
used in the Linux kernel build, for example. If no output is returned
from the command, then we don't append a -I path the the makedepend
options.

Also, use -include to avoid error message when make initially fails to
include the non-existent depend file.

The platform-specific overrides to the DRI drivers were being ignored
because the default was being set first. Instead, have the default be a
fallback after the platform checks.

Avoids AVC warnings when allocating executable memory by first checking
if the current process has permission to do so.

This change adds -fno-strict-aliasing when using gcc and g++, just like
the existing configs.

The conditional in src/mesa/Makefile currently hardcodes the cases where
libOSMesa can be built on libGL. Likewise, the xlib case always includes
libOSMesa in the stand-alone target.

This changes the conditional to a loop over the DRIVER_DIRS variable.
This means that any driver configuration can enable or disable osmesa.
The current "stand-alone" rule is changed so that DRIVER_DIRS=x11 and
DRIVER_DIRS="x11 osmesa" are both respected.

The configure option is changed to --enable-gl-osmesa as this change
allows libOSMesa to be built upon any of the libGL-enabling drivers.

Two new configure options to add -m32 or -m64 to the CFLAGS and CXXFLAGS
when GCC is in use. By default, the user supplied options are
environment variables are respected, but these options are quick helps
for the common case of x86/x86_64 using GCC.

Changed the text for the default demos to be "auto" instead of "yes"
since that didn't make much sense in this context. Added an example
value for the --with-dri-drivers option as suggested by Brian.

Point bug reports to Bugzilla like bugs.html. Also, a warning from
autoconf w.r.t. AC_OUTPUT was cleaned up.

Brian suggested that there should be more consistency using xlib vs. x11
in the configure script. Changed the options and variables to suit.

Allow the user to disable use of assembly code through the --disable-asm
option. This is only relevant on the platforms where assembly is
normally enabled such as Linux and FreeBSD.