From d798e80cc8262955ea57d516249c0969e298a395 Mon Sep 17 00:00:00 2001
From: Brendan King <Brendan.King@imgtec.com>
Date: Thu, 11 Jun 2020 12:29:51 +0100
Subject: [PATCH 35/58] meson: allow libGL to be built without GLX

If Meson is run with option "glx" set to "null", build the
OpenGL library without GLX.

The "eglBindAPI workaround for dEQP bug" change to eglcurrent.h
(commit 2d46c91040aeb8ebad486214159c34417fbc87db) has been
modified to use a new EGL_WITH_OPENGL define, which indicates
whether OpenGL is present or not. This allows EGL to be used
with OpenGL on platforms other than X11.
---
 meson.build               | 10 +++++++---
 meson_options.txt         |  2 +-
 src/egl/main/eglcurrent.h |  7 +++----
 src/glx/meson.build       | 20 ++++++++++++++++----
 src/meson.build           |  2 +-
 5 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/meson.build b/meson.build
index b4d5b849f8b..e021a896a0a 100644
--- a/meson.build
+++ b/meson.build
@@ -484,7 +484,7 @@ elif _egl == 'enabled'
     error('EGL requires dri, haiku, or windows')
   elif not with_shared_glapi
     error('EGL requires shared-glapi')
-  elif not ['disabled', 'dri'].contains(with_glx)
+  elif not ['disabled', 'dri', 'null'].contains(with_glx)
     error('EGL requires dri, but a GLX is being built without dri')
   elif host_machine.system() == 'darwin'
     error('EGL is not available on MacOS')
@@ -510,6 +510,10 @@ if with_egl and not _platforms.contains(egl_native_platform)
   error('-Degl-native-platform does not specify an enabled platform')
 endif
 
+if with_egl and with_opengl and with_glx != 'disabled'
+   pre_args += '-DEGL_WITH_OPENGL'
+endif
+
 if 'x11' in _platforms
   _platforms += 'xcb'
 endif
@@ -572,7 +576,7 @@ if with_platform_windows and with_shared_glapi
   pre_args += '-DUSE_TLS_BEHIND_FUNCTIONS'
 endif
 
-if with_glx != 'disabled'
+if with_glx != 'disabled' and with_glx != 'null'
   if not (with_platform_x11 and with_any_opengl)
     error('Cannot build GLX support without X11 platform support and at least one OpenGL API')
   elif with_glx == 'xlib'
@@ -630,7 +634,7 @@ 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
+  if (with_glx == 'disabled' or with_glx == 'null') and not with_egl and not with_gbm
     error('building dri drivers require at least one windowing system')
   endif
 endif
diff --git a/meson_options.txt b/meson_options.txt
index d76cc4b0405..65f32547267 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -306,7 +306,7 @@ option(
   'glx',
   type : 'combo',
   value : 'auto',
-  choices : ['auto', 'disabled', 'dri', 'xlib'],
+  choices : ['auto', 'disabled', 'dri', 'xlib', 'null'],
   description : 'Build support for GLX platform'
 )
 option(
diff --git a/src/egl/main/eglcurrent.h b/src/egl/main/eglcurrent.h
index 32570970947..dcc418afd6f 100644
--- a/src/egl/main/eglcurrent.h
+++ b/src/egl/main/eglcurrent.h
@@ -71,11 +71,10 @@ struct _egl_thread_info
 static inline EGLBoolean
 _eglIsApiValid(EGLenum api)
 {
-#ifndef HAVE_X11_PLATFORM
-   /* OpenGL is not a valid/supported API on Android */
-   return api == EGL_OPENGL_ES_API;
-#else
+#ifdef EGL_WITH_OPENGL
    return (api == EGL_OPENGL_ES_API || api == EGL_OPENGL_API);
+#else
+   return api == EGL_OPENGL_ES_API;
 #endif
 }
 
diff --git a/src/glx/meson.build b/src/glx/meson.build
index 8f642d5e14b..605a9717e37 100644
--- a/src/glx/meson.build
+++ b/src/glx/meson.build
@@ -122,7 +122,15 @@ else
   )
 endif
 
-libglx = static_library(
+gl_lib_cargs = [
+  '-D_REENTRANT',
+]
+
+if with_glx == 'null'
+  libglx_link = [libglapi]
+  libglx_link_whole = [libglapi_static]
+else
+  libglx = static_library(
   'glx',
   [files_libglx, glx_generated],
   include_directories : [inc_include, inc_src, inc_mapi, inc_mesa, inc_gallium, inc_gallium_aux, inc_glapi, inc_loader],
@@ -138,13 +146,17 @@ libglx = static_library(
     idep_mesautil, idep_xmlconfig,
     dep_libdrm, dep_dri2proto, dep_glproto, dep_x11, dep_glvnd,
   ],
-)
+  )
+
+  libglx_link = [libglapi_static,libglapi]
+  libglx_link_whole = [libglx]
+endif
 
 libgl = shared_library(
   gl_lib_name,
   [],
-  link_with : [libglapi_static, libglapi],
-  link_whole : libglx,
+  link_with : libglx_link,
+  link_whole : libglx_link_whole,
   link_args : [ld_args_bsymbolic, ld_args_gc_sections, extra_ld_args_libgl],
   dependencies : [
     dep_libdrm, dep_dl, dep_m, dep_thread, dep_x11, dep_xcb_glx, dep_xcb,
diff --git a/src/meson.build b/src/meson.build
index 91aca307c87..0846a6035c9 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -127,7 +127,7 @@ endif
 if with_gallium
   subdir('mesa')
   subdir('gallium')
-  if with_glx == 'dri'
+  if with_glx == 'dri' or with_glx == 'null'
      subdir('glx')
   endif
   # This has to be here since it requires libgallium, and subdir cannot
-- 
2.25.1