mesa: Retire classic OSMesa.

The classic OSMesa renders directly into user memory using
src/mesa/swrast, while gallium OSMesa renders using softpipe or llvmpipe
and copies out at glFlush() time.  This would make gallium look like a
worse choice for OSMesa, except that swrast is:

1) Painfully slow to render compared to llvmpipe
2) Incorrect at derivatives
3) Limited to GL 2.1 instead of GL 4.6

In my survey of OSMesa users, debian was the remaining holdout with
classic OSMesa in use on hurd and some rare non-LLVM-supported
architectures (sh4, alpha, etc.).  As of today, they've switched to
softpipe-based gallium OSMesa for them.

To prevent people from running the wrong OSMesa (to the extent that
running OSMesa can ever be the right thing), delete the classic
version.

Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>

Closes: #320
Closes: #877
Closes: #2297
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/1243>

.gitlab-ci.yml

@@ -643,7 +643,7 @@ meson-gallium:
     GALLIUM_DRIVERS: "iris,nouveau,kmsro,r300,r600,freedreno,swr,swrast,svga,v3d,vc4,virgl,etnaviv,panfrost,lima,zink"
     VULKAN_DRIVERS: swrast
     EXTRA_OPTION: >
-      -D osmesa=gallium
+      -D osmesa=true
       -D tools=all
       -D werror=true
   script:
@@ -675,27 +675,12 @@ meson-release:
     GALLIUM_DRIVERS: "nouveau,kmsro,freedreno,r300,svga,v3d,vc4,virgl,etnaviv,panfrost,lima,zink"
     BUILDTYPE: "release"
     EXTRA_OPTION: >
-      -D osmesa=none
+      -D osmesa=false
       -D tools=all
       -D werror=true
   script:
     - .gitlab-ci/meson-build.sh
 
-meson-classic:
-  extends: .meson-build
-  variables:
-    UNWIND: "enabled"
-    DRI_LOADERS: >
-      -D glx=dri
-      -D gbm=enabled
-      -D egl=enabled
-      -D platforms=x11,wayland
-    DRI_DRIVERS: "auto"
-    EXTRA_OPTION: >
-      -D osmesa=classic
-      -D tools=all
-      -D werror=true
-
 meson-android:
   extends:
     - .meson-cross
@@ -741,7 +726,7 @@ meson-android:
       -D gbm=disabled
       -D egl=enabled
       -D platforms=[]
-      -D osmesa=none
+      -D osmesa=false
     GALLIUM_ST: >
       -D dri3=disabled
       -D gallium-vdpau=disabled
@@ -892,7 +877,7 @@ meson-vulkan:
       -D gbm=disabled
       -D egl=disabled
       -D platforms=x11,wayland
-      -D osmesa=none
+      -D osmesa=false
     GALLIUM_ST: >
       -D dri3=enabled
       -D gallium-vdpau=disabled
@@ -957,7 +942,7 @@ meson-mingw32-x86_64:
     GALLIUM_DRIVERS: "swrast"
     EXTRA_OPTION: >
       -Dllvm=disabled
-      -Dosmesa=gallium
+      -Dosmesa=true
       --cross-file=.gitlab-ci/x86_64-w64-mingw32
 
 .test:

docs/osmesa.rst

@@ -11,11 +11,10 @@ renderings: OSMesaCreateContext(), OSMesaMakeCurrent(), and
 OSMesaDestroyContext(). See the Mesa/include/GL/osmesa.h header for more
 information about the API functions.
 
-The OSMesa interface may be used with any of three software renderers:
+The OSMesa interface may be used with the gallium software renderers:
 
 #. llvmpipe - this is the high-performance Gallium LLVM driver
 #. softpipe - this it the reference Gallium software driver
-#. swrast - this is the legacy Mesa software rasterizer
 
 There are several examples of OSMesa in the mesa/demos repository.
 
@@ -26,7 +25,7 @@ Configure and build Mesa with something like:
 
 ::
 
-   meson builddir -Dosmesa=gallium -Dgallium-drivers=swrast -Ddri-drivers=[] -Dvulkan-drivers=[] -Dprefix=$PWD/builddir/install
+   meson builddir -Dosmesa=true -Dgallium-drivers=swrast -Ddri-drivers=[] -Dvulkan-drivers=[] -Dprefix=$PWD/builddir/install
    ninja -C builddir install
 
 Make sure you have LLVM installed first if you want to use the llvmpipe

docs/relnotes/new_features.txt

@@ -5,3 +5,4 @@ Removed GL_NV_point_sprite for classic swrast.
 driconf: remove glx_disable_oml_sync_control, glx_disable_sgi_video_sync, and glx_disable_ext_buffer_age
 Removed support for loading DRI drivers older than Mesa 8.0, including all DRI1 support
 Add support for VK_VALVE_mutable_descriptor_type on RADV
+Removed classic OSMesa in favor of the newly improved gallium OSMesa

include/meson.build

@@ -96,7 +96,7 @@ if with_egl
   )
 endif
 
-if with_osmesa != 'none'
+if with_osmesa
   install_headers('GL/osmesa.h', subdir : 'GL')
 endif
 

meson.build

@@ -517,8 +517,8 @@ if with_any_vk and (with_platform_x11 and not with_dri3)
   error('Vulkan drivers require dri3 for X11 support')
 endif
 if with_dri
-  if with_glx == 'disabled' and not with_egl and not with_gbm and with_osmesa != 'classic'
-    error('building dri drivers require at least one windowing system or classic osmesa')
+  if with_glx == 'disabled' and not with_egl and not with_gbm
+    error('building dri drivers require at least one windowing system')
   endif
 endif
 
@@ -1737,8 +1737,8 @@ else
   dep_unwind = null_dep
 endif
 
-if with_osmesa != 'none'
-  if with_osmesa == 'gallium' and not with_gallium_softpipe
+if with_osmesa
+  if not with_gallium_softpipe
     error('OSMesa gallium requires gallium softpipe or llvmpipe.')
   endif
   if host_machine.system() == 'windows'
@@ -1976,13 +1976,9 @@ lines = ['',
                                                     with_gles2 ? 'yes' : 'no'),
 ]
 
-if with_osmesa != 'none'
+if with_osmesa
   lines += ''
-  suffix = ''
-  if with_osmesa == 'gallium'
-    suffix = '(Gallium)'
-  endif
-  lines += 'OSMesa:          lib' + osmesa_lib_name + suffix
+  lines += 'OSMesa:          lib' + osmesa_lib_name
 else
   lines += 'OSMesa:          no'
 endif

meson_options.txt

@@ -362,9 +362,8 @@ option(
 )
 option(
   'osmesa',
-  type : 'combo',
-  value : 'none',
-  choices : ['none', 'classic', 'gallium'],
+  type : 'boolean',
+  value : false,
   description : 'Build OSmesa.'
 )
 option(

src/gallium/meson.build

@@ -180,7 +180,7 @@ if with_dri
   subdir('frontends/dri')
   subdir('targets/dri')
 endif
-if with_osmesa == 'gallium'
+if with_osmesa
   subdir('frontends/osmesa')
   subdir('targets/osmesa')
 endif

src/mesa/drivers/osmesa/meson.build

@@ -1,50 +0,0 @@
-# Copyright © 2017 Dylan Baker
-
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-# SOFTWARE.
-
-osmesa_link_with = []
-
-if with_shared_glapi
-  osmesa_link_with += libglapi
-endif
-
-libosmesa = shared_library(
-  osmesa_lib_name,
-  ['osmesa.c', glapitable_h, glapitemp_h],
-  gnu_symbol_visibility : 'hidden',
-  link_args : ld_args_gc_sections,
-  include_directories : [
-    inc_include, inc_src, inc_mapi, inc_mesa, inc_gallium, inc_gallium_aux,
-  ],
-  link_whole : libglapi_static,
-  link_with : [libmesa_classic, osmesa_link_with],
-  dependencies : [dep_thread, dep_selinux],
-  name_prefix : host_machine.system() == 'windows' ? '' : 'lib',  # otherwise mingw will create libosmesa.dll
-  soversion : host_machine.system() == 'windows' ? '' : '8',
-  version : '8.0.0',
-  install : true,
-)
-
-pkg.generate(
-  name : 'osmesa',
-  description : 'Mesa Off-screen Rendering Library',
-  version : '8.0.0',
-  libraries : libosmesa,
-  libraries_private : gl_priv_libs,
-)

src/mesa/drivers/osmesa/osmesa.def

@@ -1,16 +0,0 @@
-;DESCRIPTION 'Mesa OSMesa lib for Win32'
-VERSION 4.1
-
-EXPORTS
-	OSMesaColorClamp
-	OSMesaCreateContext
-	OSMesaCreateContextAttribs
-	OSMesaCreateContextExt
-	OSMesaDestroyContext
-	OSMesaMakeCurrent
-	OSMesaGetCurrentContext
-	OSMesaPixelStore
-	OSMesaGetIntegerv
-	OSMesaGetDepthBuffer
-	OSMesaGetColorBuffer
-	OSMesaGetProcAddress

src/mesa/main/extensions.c

@@ -116,7 +116,7 @@ _mesa_override_extensions(struct gl_context *ctx)
 
 /**
  * Enable all extensions suitable for a software-only renderer.
- * This is a convenience function used by the XMesa, OSMesa, GGI drivers, etc.
+ * This is a convenience function used by the mesa/swrast drivers.
  */
 void
 _mesa_enable_sw_extensions(struct gl_context *ctx)

src/mesa/meson.build

@@ -760,9 +760,6 @@ libmesa_gallium = static_library(
 )
 
 subdir('drivers/dri')
-if with_osmesa == 'classic'
-  subdir('drivers/osmesa')
-endif
 if with_glx == 'xlib'
   subdir('drivers/x11')
 endif