glthread: track instance divisor changes
[mesa.git] / src / mesa / main / extensions.c
index a57d5baeafd819db0f38f97219850b02fbbda7df..6ded1bb426983fc1262405809f6f2c07d31d8ff1 100644 (file)
@@ -31,7 +31,7 @@
 
 
 #include "glheader.h"
-#include "imports.h"
+
 #include "context.h"
 #include "extensions.h"
 #include "macros.h"
 
 struct gl_extensions _mesa_extension_override_enables;
 struct gl_extensions _mesa_extension_override_disables;
-static char *extra_extensions = NULL;
-static char *cant_disable_extensions = NULL;
-
-enum {
-   DISABLE = 0,
-   GLL = 1 << API_OPENGL_COMPAT,       /* GL Legacy / Compatibility */
-   GLC = 1 << API_OPENGL_CORE,  /* GL Core */
-   GL  = (1 << API_OPENGL_COMPAT) | (1 << API_OPENGL_CORE),
-   ES1 = 1 << API_OPENGLES,
-   ES2 = 1 << API_OPENGLES2,
-   ES3 = 1 << (API_OPENGL_LAST + 1),
-   ES31 = 1 << (API_OPENGL_LAST + 2),
-};
-
-/**
- * \brief An element of the \c extension_table.
- */
-struct extension {
-   /** Name of extension, such as "GL_ARB_depth_clamp". */
-   const char *name;
-
-   /** Offset (in bytes) of the corresponding member in struct gl_extensions. */
-   size_t offset;
-
-   /** Set of API's in which the extension exists, as a bitset. */
-   uint8_t api_set;
-
-   /** Year the extension was proposed or approved.  Used to sort the 
-    * extension string chronologically. */
-   uint16_t year;
-};
 
+#define MAX_UNRECOGNIZED_EXTENSIONS 16
+static struct {
+   char *env;
+   const char *names[MAX_UNRECOGNIZED_EXTENSIONS];
+} unrecognized_extensions;
 
 /**
  * Given a member \c x of struct gl_extensions, return offset of
@@ -78,377 +52,57 @@ struct extension {
  */
 #define o(x) offsetof(struct gl_extensions, x)
 
-
-/**
- * \brief Table of supported OpenGL extensions for all API's.
- */
-static const struct extension extension_table[] = {
-   /* ARB Extensions */
-   { "GL_ARB_ES2_compatibility",                   o(ARB_ES2_compatibility),                   GL,             2009 },
-   { "GL_ARB_ES3_compatibility",                   o(ARB_ES3_compatibility),                   GL,             2012 },
-   { "GL_ARB_arrays_of_arrays",                    o(ARB_arrays_of_arrays),                    GL,             2012 },
-   { "GL_ARB_base_instance",                       o(ARB_base_instance),                       GL,             2011 },
-   { "GL_ARB_blend_func_extended",                 o(ARB_blend_func_extended),                 GL,             2009 },
-   { "GL_ARB_buffer_storage",                      o(ARB_buffer_storage),                      GL,             2013 },
-   { "GL_ARB_clear_buffer_object",                 o(dummy_true),                              GL,             2012 },
-   { "GL_ARB_clear_texture",                       o(ARB_clear_texture),                       GL,             2013 },
-   { "GL_ARB_clip_control",                        o(ARB_clip_control),                        GL,             2014 },
-   { "GL_ARB_color_buffer_float",                  o(ARB_color_buffer_float),                  GL,             2004 },
-   { "GL_ARB_compressed_texture_pixel_storage",    o(dummy_true),                              GL,             2011 },
-   { "GL_ARB_compute_shader",                      o(ARB_compute_shader),                      GL,             2012 },
-   { "GL_ARB_conditional_render_inverted",         o(ARB_conditional_render_inverted),         GL,             2014 },
-   { "GL_ARB_copy_buffer",                         o(dummy_true),                              GL,             2008 },
-   { "GL_ARB_copy_image",                          o(ARB_copy_image),                          GL,             2012 },
-   { "GL_ARB_conservative_depth",                  o(ARB_conservative_depth),                  GL,             2011 },
-   { "GL_ARB_debug_output",                        o(dummy_true),                              GL,             2009 },
-   { "GL_ARB_depth_buffer_float",                  o(ARB_depth_buffer_float),                  GL,             2008 },
-   { "GL_ARB_depth_clamp",                         o(ARB_depth_clamp),                         GL,             2003 },
-   { "GL_ARB_depth_texture",                       o(ARB_depth_texture),                       GLL,            2001 },
-   { "GL_ARB_derivative_control",                  o(ARB_derivative_control),                  GL,             2014 },
-   { "GL_ARB_direct_state_access",                 o(dummy_true),                              GLC,            2014 },
-   { "GL_ARB_draw_buffers",                        o(dummy_true),                              GL,             2002 },
-   { "GL_ARB_draw_buffers_blend",                  o(ARB_draw_buffers_blend),                  GL,             2009 },
-   { "GL_ARB_draw_elements_base_vertex",           o(ARB_draw_elements_base_vertex),           GL,             2009 },
-   { "GL_ARB_draw_indirect",                       o(ARB_draw_indirect),                       GLC,            2010 },
-   { "GL_ARB_draw_instanced",                      o(ARB_draw_instanced),                      GL,             2008 },
-   { "GL_ARB_explicit_attrib_location",            o(ARB_explicit_attrib_location),            GL,             2009 },
-   { "GL_ARB_explicit_uniform_location",           o(ARB_explicit_uniform_location),           GL,             2012 },
-   { "GL_ARB_fragment_coord_conventions",          o(ARB_fragment_coord_conventions),          GL,             2009 },
-   { "GL_ARB_fragment_layer_viewport",             o(ARB_fragment_layer_viewport),             GLC,            2012 },
-   { "GL_ARB_fragment_program",                    o(ARB_fragment_program),                    GLL,            2002 },
-   { "GL_ARB_fragment_program_shadow",             o(ARB_fragment_program_shadow),             GLL,            2003 },
-   { "GL_ARB_fragment_shader",                     o(ARB_fragment_shader),                     GL,             2002 },
-   { "GL_ARB_framebuffer_no_attachments",          o(ARB_framebuffer_no_attachments),          GL,             2012 },
-   { "GL_ARB_framebuffer_object",                  o(ARB_framebuffer_object),                  GL,             2005 },
-   { "GL_ARB_framebuffer_sRGB",                    o(EXT_framebuffer_sRGB),                    GL,             1998 },
-   { "GL_ARB_get_program_binary",                  o(dummy_true),                              GL,             2010 },
-   { "GL_ARB_get_texture_sub_image",               o(dummy_true),                              GL,             2014 },
-   { "GL_ARB_gpu_shader5",                         o(ARB_gpu_shader5),                         GLC,            2010 },
-   { "GL_ARB_gpu_shader_fp64",                     o(ARB_gpu_shader_fp64),                     GLC,            2010 },
-   { "GL_ARB_half_float_pixel",                    o(dummy_true),                              GL,             2003 },
-   { "GL_ARB_half_float_vertex",                   o(ARB_half_float_vertex),                   GL,             2008 },
-   { "GL_ARB_instanced_arrays",                    o(ARB_instanced_arrays),                    GL,             2008 },
-   { "GL_ARB_internalformat_query",                o(ARB_internalformat_query),                GL,             2011 },
-   { "GL_ARB_invalidate_subdata",                  o(dummy_true),                              GL,             2012 },
-   { "GL_ARB_map_buffer_alignment",                o(dummy_true),                              GL,             2011 },
-   { "GL_ARB_map_buffer_range",                    o(ARB_map_buffer_range),                    GL,             2008 },
-   { "GL_ARB_multi_bind",                          o(dummy_true),                              GL,             2013 },
-   { "GL_ARB_multi_draw_indirect",                 o(ARB_draw_indirect),                       GLC,            2012 },
-   { "GL_ARB_multisample",                         o(dummy_true),                              GLL,            1994 },
-   { "GL_ARB_multitexture",                        o(dummy_true),                              GLL,            1998 },
-   { "GL_ARB_occlusion_query2",                    o(ARB_occlusion_query2),                    GL,             2003 },
-   { "GL_ARB_occlusion_query",                     o(ARB_occlusion_query),                     GLL,            2001 },
-   { "GL_ARB_pipeline_statistics_query",           o(ARB_pipeline_statistics_query),           GL,             2014 },
-   { "GL_ARB_pixel_buffer_object",                 o(EXT_pixel_buffer_object),                 GL,             2004 },
-   { "GL_ARB_point_parameters",                    o(EXT_point_parameters),                    GLL,            1997 },
-   { "GL_ARB_point_sprite",                        o(ARB_point_sprite),                        GL,             2003 },
-   { "GL_ARB_program_interface_query",             o(dummy_true),                              GL,             2012 },
-   { "GL_ARB_provoking_vertex",                    o(EXT_provoking_vertex),                    GL,             2009 },
-   { "GL_ARB_robustness",                          o(dummy_true),                              GL,             2010 },
-   { "GL_ARB_sample_shading",                      o(ARB_sample_shading),                      GL,             2009 },
-   { "GL_ARB_sampler_objects",                     o(dummy_true),                              GL,             2009 },
-   { "GL_ARB_seamless_cube_map",                   o(ARB_seamless_cube_map),                   GL,             2009 },
-   { "GL_ARB_seamless_cubemap_per_texture",        o(AMD_seamless_cubemap_per_texture),        GL,             2013 },
-   { "GL_ARB_separate_shader_objects",             o(dummy_true),                              GL,             2010 },
-   { "GL_ARB_shader_atomic_counters",              o(ARB_shader_atomic_counters),              GL,             2011 },
-   { "GL_ARB_shader_bit_encoding",                 o(ARB_shader_bit_encoding),                 GL,             2010 },
-   { "GL_ARB_shader_image_load_store",             o(ARB_shader_image_load_store),             GL,             2011 },
-   { "GL_ARB_shader_image_size",                   o(ARB_shader_image_size),                   GL,             2012 },
-   { "GL_ARB_shader_objects",                      o(dummy_true),                              GL,             2002 },
-   { "GL_ARB_shader_precision",                    o(ARB_shader_precision),                    GL,             2010 },
-   { "GL_ARB_shader_stencil_export",               o(ARB_shader_stencil_export),               GL,             2009 },
-   { "GL_ARB_shader_storage_buffer_object",        o(ARB_shader_storage_buffer_object),        GL,             2012 },
-   { "GL_ARB_shader_subroutine",                   o(ARB_shader_subroutine),                   GLC,            2010 },
-   { "GL_ARB_shader_texture_lod",                  o(ARB_shader_texture_lod),                  GL,             2009 },
-   { "GL_ARB_shading_language_100",                o(dummy_true),                              GLL,            2003 },
-   { "GL_ARB_shading_language_packing",            o(ARB_shading_language_packing),            GL,             2011 },
-   { "GL_ARB_shading_language_420pack",            o(ARB_shading_language_420pack),            GL,             2011 },
-   { "GL_ARB_shadow",                              o(ARB_shadow),                              GLL,            2001 },
-   { "GL_ARB_stencil_texturing",                   o(ARB_stencil_texturing),                   GL,             2012 },
-   { "GL_ARB_sync",                                o(ARB_sync),                                GL,             2003 },
-   { "GL_ARB_texture_barrier",                     o(NV_texture_barrier),                      GL,             2014 },
-   { "GL_ARB_tessellation_shader",                 o(ARB_tessellation_shader),                 GLC,            2009 },
-   { "GL_ARB_texture_border_clamp",                o(ARB_texture_border_clamp),                GLL,            2000 },
-   { "GL_ARB_texture_buffer_object",               o(ARB_texture_buffer_object),               GLC,            2008 },
-   { "GL_ARB_texture_buffer_object_rgb32",         o(ARB_texture_buffer_object_rgb32),         GLC,            2009 },
-   { "GL_ARB_texture_buffer_range",                o(ARB_texture_buffer_range),                GLC,            2012 },
-   { "GL_ARB_texture_compression",                 o(dummy_true),                              GLL,            2000 },
-   { "GL_ARB_texture_compression_bptc",            o(ARB_texture_compression_bptc),            GL,             2010 },
-   { "GL_ARB_texture_compression_rgtc",            o(ARB_texture_compression_rgtc),            GL,             2004 },
-   { "GL_ARB_texture_cube_map",                    o(ARB_texture_cube_map),                    GLL,            1999 },
-   { "GL_ARB_texture_cube_map_array",              o(ARB_texture_cube_map_array),              GL,             2009 },
-   { "GL_ARB_texture_env_add",                     o(dummy_true),                              GLL,            1999 },
-   { "GL_ARB_texture_env_combine",                 o(ARB_texture_env_combine),                 GLL,            2001 },
-   { "GL_ARB_texture_env_crossbar",                o(ARB_texture_env_crossbar),                GLL,            2001 },
-   { "GL_ARB_texture_env_dot3",                    o(ARB_texture_env_dot3),                    GLL,            2001 },
-   { "GL_ARB_texture_float",                       o(ARB_texture_float),                       GL,             2004 },
-   { "GL_ARB_texture_gather",                      o(ARB_texture_gather),                      GL,             2009 },
-   { "GL_ARB_texture_mirrored_repeat",             o(dummy_true),                              GLL,            2001 },
-   { "GL_ARB_texture_mirror_clamp_to_edge",        o(ARB_texture_mirror_clamp_to_edge),        GL,             2013 },
-   { "GL_ARB_texture_multisample",                 o(ARB_texture_multisample),                 GL,             2009 },
-   { "GL_ARB_texture_non_power_of_two",            o(ARB_texture_non_power_of_two),            GL,             2003 },
-   { "GL_ARB_texture_query_levels",                o(ARB_texture_query_levels),                GL,             2012 },
-   { "GL_ARB_texture_query_lod",                   o(ARB_texture_query_lod),                   GL,             2009 },
-   { "GL_ARB_texture_rectangle",                   o(NV_texture_rectangle),                    GL,             2004 },
-   { "GL_ARB_texture_rgb10_a2ui",                  o(ARB_texture_rgb10_a2ui),                  GL,             2009 },
-   { "GL_ARB_texture_rg",                          o(ARB_texture_rg),                          GL,             2008 },
-   { "GL_ARB_texture_stencil8",                    o(ARB_texture_stencil8),                    GL,             2013 },
-   { "GL_ARB_texture_storage",                     o(dummy_true),                              GL,             2011 },
-   { "GL_ARB_texture_storage_multisample",         o(ARB_texture_multisample),                 GL,             2012 },
-   { "GL_ARB_texture_view",                        o(ARB_texture_view),                        GL,             2012 },
-   { "GL_ARB_texture_swizzle",                     o(EXT_texture_swizzle),                     GL,             2008 },
-   { "GL_ARB_timer_query",                         o(ARB_timer_query),                         GL,             2010 },
-   { "GL_ARB_transform_feedback2",                 o(ARB_transform_feedback2),                 GL,             2010 },
-   { "GL_ARB_transform_feedback3",                 o(ARB_transform_feedback3),                 GL,             2010 },
-   { "GL_ARB_transform_feedback_instanced",        o(ARB_transform_feedback_instanced),        GL,             2011 },
-   { "GL_ARB_transpose_matrix",                    o(dummy_true),                              GLL,            1999 },
-   { "GL_ARB_uniform_buffer_object",               o(ARB_uniform_buffer_object),               GL,             2009 },
-   { "GL_ARB_vertex_array_bgra",                   o(EXT_vertex_array_bgra),                   GL,             2008 },
-   { "GL_ARB_vertex_array_object",                 o(dummy_true),                              GL,             2006 },
-   { "GL_ARB_vertex_attrib_binding",               o(dummy_true),                              GL,             2012 },
-   { "GL_ARB_vertex_buffer_object",                o(dummy_true),                              GLL,            2003 },
-   { "GL_ARB_vertex_program",                      o(ARB_vertex_program),                      GLL,            2002 },
-   { "GL_ARB_vertex_shader",                       o(ARB_vertex_shader),                       GL,             2002 },
-   { "GL_ARB_vertex_attrib_64bit",                 o(ARB_vertex_attrib_64bit),                 GLC,            2010 },
-   { "GL_ARB_vertex_type_10f_11f_11f_rev",         o(ARB_vertex_type_10f_11f_11f_rev),         GL,             2013 },
-   { "GL_ARB_vertex_type_2_10_10_10_rev",          o(ARB_vertex_type_2_10_10_10_rev),          GL,             2009 },
-   { "GL_ARB_viewport_array",                      o(ARB_viewport_array),                      GLC,            2010 },
-   { "GL_ARB_window_pos",                          o(dummy_true),                              GLL,            2001 },
-   /* EXT extensions */
-   { "GL_EXT_abgr",                                o(dummy_true),                              GL,             1995 },
-   { "GL_EXT_bgra",                                o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_blend_color",                         o(EXT_blend_color),                         GLL,            1995 },
-   { "GL_EXT_blend_equation_separate",             o(EXT_blend_equation_separate),             GL,             2003 },
-   { "GL_EXT_blend_func_separate",                 o(EXT_blend_func_separate),                 GLL,            1999 },
-   { "GL_EXT_discard_framebuffer",                 o(dummy_true),                                    ES1 | ES2, 2009 },
-   { "GL_EXT_blend_minmax",                        o(EXT_blend_minmax),                        GLL | ES1 | ES2, 1995 },
-   { "GL_EXT_blend_subtract",                      o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_compiled_vertex_array",               o(dummy_true),                              GLL,            1996 },
-   { "GL_EXT_copy_texture",                        o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_depth_bounds_test",                   o(EXT_depth_bounds_test),                   GL,             2002 },
-   { "GL_EXT_draw_buffers",                        o(dummy_true),                                         ES2, 2012 },
-   { "GL_EXT_draw_buffers2",                       o(EXT_draw_buffers2),                       GL,             2006 },
-   { "GL_EXT_draw_instanced",                      o(ARB_draw_instanced),                      GL,             2006 },
-   { "GL_EXT_draw_range_elements",                 o(dummy_true),                              GLL,            1997 },
-   { "GL_EXT_fog_coord",                           o(dummy_true),                              GLL,            1999 },
-   { "GL_EXT_framebuffer_blit",                    o(dummy_true),                              GL,             2005 },
-   { "GL_EXT_framebuffer_multisample",             o(EXT_framebuffer_multisample),             GL,             2005 },
-   { "GL_EXT_framebuffer_multisample_blit_scaled", o(EXT_framebuffer_multisample_blit_scaled), GL,             2011 },
-   { "GL_EXT_framebuffer_object",                  o(dummy_true),                              GLL,            2000 },
-   { "GL_EXT_framebuffer_sRGB",                    o(EXT_framebuffer_sRGB),                    GL,             1998 },
-   { "GL_EXT_gpu_program_parameters",              o(EXT_gpu_program_parameters),              GLL,            2006 },
-   { "GL_EXT_gpu_shader4",                         o(EXT_gpu_shader4),                         GL,             2006 },
-   { "GL_EXT_map_buffer_range",                    o(ARB_map_buffer_range),                          ES1 | ES2, 2012 },
-   { "GL_EXT_multi_draw_arrays",                   o(dummy_true),                              GLL | ES1 | ES2, 1999 },
-   { "GL_EXT_packed_depth_stencil",                o(dummy_true),                              GL,             2005 },
-   { "GL_EXT_packed_float",                        o(EXT_packed_float),                        GL,             2004 },
-   { "GL_EXT_packed_pixels",                       o(dummy_true),                              GLL,            1997 },
-   { "GL_EXT_pixel_buffer_object",                 o(EXT_pixel_buffer_object),                 GL,             2004 },
-   { "GL_EXT_point_parameters",                    o(EXT_point_parameters),                    GLL,            1997 },
-   { "GL_EXT_polygon_offset",                      o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_polygon_offset_clamp",                o(EXT_polygon_offset_clamp),                GL,             2014 },
-   { "GL_EXT_provoking_vertex",                    o(EXT_provoking_vertex),                    GL,             2009 },
-   { "GL_EXT_rescale_normal",                      o(dummy_true),                              GLL,            1997 },
-   { "GL_EXT_secondary_color",                     o(dummy_true),                              GLL,            1999 },
-   { "GL_EXT_separate_shader_objects",             o(dummy_true),                                         ES2, 2013 },
-   { "GL_EXT_separate_specular_color",             o(dummy_true),                              GLL,            1997 },
-   { "GL_EXT_shader_integer_mix",                  o(EXT_shader_integer_mix),                  GL       | ES3, 2013 },
-   { "GL_EXT_shadow_funcs",                        o(ARB_shadow),                              GLL,            2002 },
-   { "GL_EXT_stencil_two_side",                    o(EXT_stencil_two_side),                    GLL,            2001 },
-   { "GL_EXT_stencil_wrap",                        o(dummy_true),                              GLL,            2002 },
-   { "GL_EXT_subtexture",                          o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_texture3D",                           o(EXT_texture3D),                           GLL,            1996 },
-   { "GL_EXT_texture_array",                       o(EXT_texture_array),                       GL,             2006 },
-   { "GL_EXT_texture_compression_dxt1",            o(ANGLE_texture_compression_dxt),           GL | ES1 | ES2, 2004 },
-   { "GL_ANGLE_texture_compression_dxt3",          o(ANGLE_texture_compression_dxt),           GL | ES1 | ES2, 2011 },
-   { "GL_ANGLE_texture_compression_dxt5",          o(ANGLE_texture_compression_dxt),           GL | ES1 | ES2, 2011 },
-   { "GL_EXT_texture_compression_latc",            o(EXT_texture_compression_latc),            GL,             2006 },
-   { "GL_EXT_texture_compression_rgtc",            o(ARB_texture_compression_rgtc),            GL,             2004 },
-   { "GL_EXT_texture_compression_s3tc",            o(EXT_texture_compression_s3tc),            GL,             2000 },
-   { "GL_EXT_texture_cube_map",                    o(ARB_texture_cube_map),                    GLL,            2001 },
-   { "GL_EXT_texture_edge_clamp",                  o(dummy_true),                              GLL,            1997 },
-   { "GL_EXT_texture_env_add",                     o(dummy_true),                              GLL,            1999 },
-   { "GL_EXT_texture_env_combine",                 o(dummy_true),                              GLL,            2000 },
-   { "GL_EXT_texture_env_dot3",                    o(EXT_texture_env_dot3),                    GLL,            2000 },
-   { "GL_EXT_texture_filter_anisotropic",          o(EXT_texture_filter_anisotropic),          GL | ES1 | ES2, 1999 },
-   { "GL_EXT_texture_format_BGRA8888",             o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_EXT_texture_rg",                          o(ARB_texture_rg),                                     ES2, 2011 },
-   { "GL_EXT_read_format_bgra",                    o(dummy_true),                                   ES1 | ES2, 2009 },
-   { "GL_EXT_texture_integer",                     o(EXT_texture_integer),                     GL,             2006 },
-   { "GL_EXT_texture_lod_bias",                    o(dummy_true),                              GLL | ES1,      1999 },
-   { "GL_EXT_texture_mirror_clamp",                o(EXT_texture_mirror_clamp),                GL,             2004 },
-   { "GL_EXT_texture_object",                      o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_texture",                             o(dummy_true),                              GLL,            1996 },
-   { "GL_EXT_texture_rectangle",                   o(NV_texture_rectangle),                    GLL,            2004 },
-   { "GL_EXT_texture_shared_exponent",             o(EXT_texture_shared_exponent),             GL,             2004 },
-   { "GL_EXT_texture_snorm",                       o(EXT_texture_snorm),                       GL,             2009 },
-   { "GL_EXT_texture_sRGB",                        o(EXT_texture_sRGB),                        GL,             2004 },
-   { "GL_EXT_texture_sRGB_decode",                 o(EXT_texture_sRGB_decode),                        GL,      2006 },
-   { "GL_EXT_texture_swizzle",                     o(EXT_texture_swizzle),                     GL,             2008 },
-   { "GL_EXT_texture_type_2_10_10_10_REV",         o(dummy_true),                                         ES2, 2008 },
-   { "GL_EXT_timer_query",                         o(EXT_timer_query),                         GL,             2006 },
-   { "GL_EXT_transform_feedback",                  o(EXT_transform_feedback),                  GL,             2011 },
-   { "GL_EXT_unpack_subimage",                     o(dummy_true),                                         ES2, 2011 },
-   { "GL_EXT_vertex_array_bgra",                   o(EXT_vertex_array_bgra),                   GL,             2008 },
-   { "GL_EXT_vertex_array",                        o(dummy_true),                              GLL,            1995 },
-   { "GL_EXT_color_buffer_float",                  o(dummy_true),                                         ES3, 2013 },
-
-   /* OES extensions */
-   { "GL_OES_blend_equation_separate",             o(EXT_blend_equation_separate),                  ES1,       2009 },
-   { "GL_OES_blend_func_separate",                 o(EXT_blend_func_separate),                      ES1,       2009 },
-   { "GL_OES_blend_subtract",                      o(dummy_true),                                   ES1,       2009 },
-   { "GL_OES_byte_coordinates",                    o(dummy_true),                                   ES1,       2002 },
-   { "GL_OES_compressed_ETC1_RGB8_texture",        o(OES_compressed_ETC1_RGB8_texture),             ES1 | ES2, 2005 },
-   { "GL_OES_compressed_paletted_texture",         o(dummy_true),                                   ES1,       2003 },
-   { "GL_OES_depth24",                             o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_OES_depth32",                             o(dummy_false),                     DISABLE,                2005 },
-   { "GL_OES_depth_texture",                       o(ARB_depth_texture),                                  ES2, 2006 },
-   { "GL_OES_depth_texture_cube_map",              o(OES_depth_texture_cube_map),                         ES2, 2012 },
-   { "GL_OES_draw_texture",                        o(OES_draw_texture),                             ES1,       2004 },
-   { "GL_OES_EGL_sync",                            o(dummy_true),                                   ES1 | ES2, 2010 },
-   /*  FIXME: Mesa expects GL_OES_EGL_image to be available in OpenGL contexts. */
-   { "GL_OES_EGL_image",                           o(OES_EGL_image),                           GL | ES1 | ES2, 2006 },
-   { "GL_OES_EGL_image_external",                  o(OES_EGL_image_external),                       ES1 | ES2, 2010 },
-   { "GL_OES_element_index_uint",                  o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_OES_fbo_render_mipmap",                   o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_OES_fixed_point",                         o(dummy_true),                                   ES1,       2002 },
-   { "GL_OES_framebuffer_object",                  o(dummy_true),                                   ES1,       2005 },
-   { "GL_OES_get_program_binary",                  o(dummy_true),                                         ES2, 2008 },
-   { "GL_OES_mapbuffer",                           o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_OES_packed_depth_stencil",                o(dummy_true),                                   ES1 | ES2, 2007 },
-   { "GL_OES_point_size_array",                    o(dummy_true),                                   ES1,       2004 },
-   { "GL_OES_point_sprite",                        o(ARB_point_sprite),                             ES1,       2004 },
-   { "GL_OES_query_matrix",                        o(dummy_true),                                   ES1,       2003 },
-   { "GL_OES_read_format",                         o(dummy_true),                              GL | ES1,       2003 },
-   { "GL_OES_rgb8_rgba8",                          o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_OES_single_precision",                    o(dummy_true),                                   ES1,       2003 },
-   { "GL_OES_standard_derivatives",                o(OES_standard_derivatives),                           ES2, 2005 },
-   { "GL_OES_stencil1",                            o(dummy_false),                     DISABLE,                2005 },
-   { "GL_OES_stencil4",                            o(dummy_false),                     DISABLE,                2005 },
-   { "GL_OES_stencil8",                            o(dummy_true),                                   ES1 | ES2, 2005 },
-   { "GL_OES_stencil_wrap",                        o(dummy_true),                                   ES1,       2002 },
-   { "GL_OES_surfaceless_context",                 o(dummy_true),                                   ES1 | ES2, 2012 },
-   { "GL_OES_texture_3D",                          o(EXT_texture3D),                                      ES2, 2005 },
-   { "GL_OES_texture_cube_map",                    o(ARB_texture_cube_map),                         ES1,       2007 },
-   { "GL_OES_texture_env_crossbar",                o(ARB_texture_env_crossbar),                     ES1,       2005 },
-   { "GL_OES_texture_float",                       o(OES_texture_float),                                  ES2, 2005 },
-   { "GL_OES_texture_float_linear",                o(OES_texture_float_linear),                           ES2, 2005 },
-   { "GL_OES_texture_half_float",                  o(OES_texture_half_float),                             ES2, 2005 },
-   { "GL_OES_texture_half_float_linear",           o(OES_texture_half_float_linear),                      ES2, 2005 },
-   { "GL_OES_texture_mirrored_repeat",             o(dummy_true),                                   ES1,       2005 },
-   { "GL_OES_texture_storage_multisample_2d_array",o(ARB_texture_multisample),                           ES31, 2014 },
-   { "GL_OES_texture_npot",                        o(ARB_texture_non_power_of_two),                 ES1 | ES2, 2005 },
-   { "GL_OES_vertex_array_object",                 o(dummy_true),                                   ES1 | ES2, 2010 },
-
-   /* KHR extensions */
-   { "GL_KHR_debug",                               o(dummy_true),                              GL,             2012 },
-   { "GL_KHR_context_flush_control",               o(dummy_true),                              GL       | ES2, 2014 },
-   { "GL_KHR_texture_compression_astc_hdr",        o(KHR_texture_compression_astc_hdr),        GL       | ES2, 2012 },
-   { "GL_KHR_texture_compression_astc_ldr",        o(KHR_texture_compression_astc_ldr),        GL       | ES2, 2012 },
-
-   /* Vendor extensions */
-   { "GL_3DFX_texture_compression_FXT1",           o(TDFX_texture_compression_FXT1),           GL,             1999 },
-   { "GL_AMD_conservative_depth",                  o(ARB_conservative_depth),                  GL,             2009 },
-   { "GL_AMD_draw_buffers_blend",                  o(ARB_draw_buffers_blend),                  GL,             2009 },
-   { "GL_AMD_performance_monitor",                 o(AMD_performance_monitor),                 GL,             2007 },
-   { "GL_AMD_pinned_memory",                       o(AMD_pinned_memory),                       GL,             2013 },
-   { "GL_AMD_seamless_cubemap_per_texture",        o(AMD_seamless_cubemap_per_texture),        GL,             2009 },
-   { "GL_AMD_shader_stencil_export",               o(ARB_shader_stencil_export),               GL,             2009 },
-   { "GL_AMD_shader_trinary_minmax",               o(dummy_true),                              GL,             2012 },
-   { "GL_AMD_vertex_shader_layer",                 o(AMD_vertex_shader_layer),                 GLC,            2012 },
-   { "GL_AMD_vertex_shader_viewport_index",        o(AMD_vertex_shader_viewport_index),        GLC,            2012 },
-   { "GL_APPLE_object_purgeable",                  o(APPLE_object_purgeable),                  GL,             2006 },
-   { "GL_APPLE_packed_pixels",                     o(dummy_true),                              GLL,            2002 },
-   { "GL_APPLE_texture_max_level",                 o(dummy_true),                                   ES1 | ES2, 2009 },
-   { "GL_APPLE_vertex_array_object",               o(dummy_true),                              GLL,            2002 },
-   { "GL_ATI_blend_equation_separate",             o(EXT_blend_equation_separate),             GL,             2003 },
-   { "GL_ATI_draw_buffers",                        o(dummy_true),                              GLL,            2002 },
-   { "GL_ATI_fragment_shader",                     o(ATI_fragment_shader),                     GLL,            2001 },
-   { "GL_ATI_separate_stencil",                    o(ATI_separate_stencil),                    GLL,            2006 },
-   { "GL_ATI_texture_compression_3dc",             o(ATI_texture_compression_3dc),             GL,             2004 },
-   { "GL_ATI_texture_env_combine3",                o(ATI_texture_env_combine3),                GLL,            2002 },
-   { "GL_ATI_texture_float",                       o(ARB_texture_float),                       GL,             2002 },
-   { "GL_ATI_texture_mirror_once",                 o(ATI_texture_mirror_once),                 GL,             2006 },
-   { "GL_IBM_multimode_draw_arrays",               o(dummy_true),                              GL,             1998 },
-   { "GL_IBM_rasterpos_clip",                      o(dummy_true),                              GLL,            1996 },
-   { "GL_IBM_texture_mirrored_repeat",             o(dummy_true),                              GLL,            1998 },
-   { "GL_INGR_blend_func_separate",                o(EXT_blend_func_separate),                 GLL,            1999 },
-   { "GL_INTEL_performance_query",                 o(INTEL_performance_query),                       GL | ES2, 2013 },
-   { "GL_MESA_pack_invert",                        o(MESA_pack_invert),                        GL,             2002 },
-   { "GL_MESA_texture_signed_rgba",                o(EXT_texture_snorm),                       GL,             2009 },
-   { "GL_MESA_window_pos",                         o(dummy_true),                              GLL,            2000 },
-   { "GL_MESA_ycbcr_texture",                      o(MESA_ycbcr_texture),                      GL,             2002 },
-   { "GL_NV_blend_square",                         o(dummy_true),                              GLL,            1999 },
-   { "GL_NV_conditional_render",                   o(NV_conditional_render),                   GL,             2008 },
-   { "GL_NV_depth_clamp",                          o(ARB_depth_clamp),                         GL,             2001 },
-   { "GL_NV_draw_buffers",                         o(dummy_true),                                         ES2, 2011 },
-   { "GL_NV_fbo_color_attachments",                o(dummy_true),                                         ES2, 2010 },
-   { "GL_NV_fog_distance",                         o(NV_fog_distance),                         GLL,            2001 },
-   { "GL_NV_fragment_program_option",              o(NV_fragment_program_option),              GLL,            2005 },
-   { "GL_NV_light_max_exponent",                   o(dummy_true),                              GLL,            1999 },
-   { "GL_NV_packed_depth_stencil",                 o(dummy_true),                              GL,             2000 },
-   { "GL_NV_point_sprite",                         o(NV_point_sprite),                         GL,             2001 },
-   { "GL_NV_primitive_restart",                    o(NV_primitive_restart),                    GLL,            2002 },
-   { "GL_NV_read_buffer",                          o(dummy_true),                              ES2,            2011 },
-   { "GL_NV_read_depth",                           o(dummy_true),                              ES2,            2011 },
-   { "GL_NV_read_depth_stencil",                   o(dummy_true),                              ES2,            2011 },
-   { "GL_NV_read_stencil",                         o(dummy_true),                              ES2,            2011 },
-   { "GL_NV_texgen_reflection",                    o(dummy_true),                              GLL,            1999 },
-   { "GL_NV_texture_barrier",                      o(NV_texture_barrier),                      GL,             2009 },
-   { "GL_NV_texture_env_combine4",                 o(NV_texture_env_combine4),                 GLL,            1999 },
-   { "GL_NV_texture_rectangle",                    o(NV_texture_rectangle),                    GLL,            2000 },
-   { "GL_NV_vdpau_interop",                        o(NV_vdpau_interop),                        GL,             2010 },
-   { "GL_S3_s3tc",                                 o(ANGLE_texture_compression_dxt),           GL,             1999 },
-   { "GL_SGIS_generate_mipmap",                    o(dummy_true),                              GLL,            1997 },
-   { "GL_SGIS_texture_border_clamp",               o(ARB_texture_border_clamp),                GLL,            1997 },
-   { "GL_SGIS_texture_edge_clamp",                 o(dummy_true),                              GLL,            1997 },
-   { "GL_SGIS_texture_lod",                        o(dummy_true),                              GLL,            1997 },
-   { "GL_SUN_multi_draw_arrays",                   o(dummy_true),                              GLL,            1999 },
-
-   { 0, 0, 0, 0 },
-};
-
+static int
+extension_name_compare(const void *name, const void *elem)
+{
+   const struct mesa_extension *entry = elem;
+   return strcmp(name, entry->name);
+}
 
 /**
  * Given an extension name, lookup up the corresponding member of struct
- * gl_extensions and return that member's offset (in bytes).  If the name is
- * not found in the \c extension_table, return 0.
+ * gl_extensions and return that member's index.  If the name is
+ * not found in the \c _mesa_extension_table, return -1.
  *
  * \param name Name of extension.
- * \return Offset of member in struct gl_extensions.
+ * \return Index of member in struct gl_extensions.
  */
-static size_t
-name_to_offset(const char* name)
+static int
+name_to_index(const char* name)
 {
-   const struct extension *i;
+   const struct mesa_extension *entry;
 
-   if (name == 0)
-      return 0;
+   if (!name)
+      return -1;
 
-   for (i = extension_table; i->name != 0; ++i) {
-      if (strcmp(name, i->name) == 0)
-        return i->offset;
-   }
+   entry = bsearch(name,
+                   _mesa_extension_table, MESA_EXTENSION_COUNT,
+                   sizeof(_mesa_extension_table[0]),
+                   extension_name_compare);
+
+   if (entry)
+      return entry - _mesa_extension_table;
 
-   return 0;
+   return -1;
 }
 
 /**
  * Overrides extensions in \c ctx based on the values in
  * _mesa_extension_override_enables and _mesa_extension_override_disables.
  */
-static void
-override_extensions_in_context(struct gl_context *ctx)
+void
+_mesa_override_extensions(struct gl_context *ctx)
 {
-   const struct extension *i;
+   unsigned i;
    const GLboolean *enables =
       (GLboolean*) &_mesa_extension_override_enables;
    const GLboolean *disables =
       (GLboolean*) &_mesa_extension_override_disables;
    GLboolean *ctx_ext = (GLboolean*)&ctx->Extensions;
 
-   for (i = extension_table; i->name != 0; ++i) {
-      size_t offset = i->offset;
+   for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
+      size_t offset = _mesa_extension_table[i].offset;
+
       assert(!enables[offset] || !disables[offset]);
       if (enables[offset]) {
          ctx_ext[offset] = 1;
@@ -488,9 +142,8 @@ _mesa_enable_sw_extensions(struct gl_context *ctx)
    ctx->Extensions.ARB_texture_env_combine = GL_TRUE;
    ctx->Extensions.ARB_texture_env_crossbar = GL_TRUE;
    ctx->Extensions.ARB_texture_env_dot3 = GL_TRUE;
-#ifdef TEXTURE_FLOAT_ENABLED
+   ctx->Extensions.ARB_texture_filter_anisotropic = GL_TRUE;
    ctx->Extensions.ARB_texture_float = GL_TRUE;
-#endif
    ctx->Extensions.ARB_texture_mirror_clamp_to_edge = GL_TRUE;
    ctx->Extensions.ARB_texture_non_power_of_two = GL_TRUE;
    ctx->Extensions.ARB_texture_rg = GL_TRUE;
@@ -503,7 +156,6 @@ _mesa_enable_sw_extensions(struct gl_context *ctx)
    ctx->Extensions.ATI_texture_compression_3dc = GL_TRUE;
    ctx->Extensions.ATI_texture_env_combine3 = GL_TRUE;
    ctx->Extensions.ATI_texture_mirror_once = GL_TRUE;
-   ctx->Extensions.ATI_separate_stencil = GL_TRUE;
    ctx->Extensions.EXT_blend_color = GL_TRUE;
    ctx->Extensions.EXT_blend_equation_separate = GL_TRUE;
    ctx->Extensions.EXT_blend_func_separate = GL_TRUE;
@@ -534,10 +186,8 @@ _mesa_enable_sw_extensions(struct gl_context *ctx)
    ctx->Extensions.EXT_gpu_program_parameters = GL_TRUE;
    ctx->Extensions.OES_standard_derivatives = GL_TRUE;
    ctx->Extensions.TDFX_texture_compression_FXT1 = GL_TRUE;
-   if (ctx->Mesa_DXTn) {
-      ctx->Extensions.ANGLE_texture_compression_dxt = GL_TRUE;
-      ctx->Extensions.EXT_texture_compression_s3tc = GL_TRUE;
-   }
+   ctx->Extensions.ANGLE_texture_compression_dxt = GL_TRUE;
+   ctx->Extensions.EXT_texture_compression_s3tc = GL_TRUE;
 }
 
 /**
@@ -545,11 +195,11 @@ _mesa_enable_sw_extensions(struct gl_context *ctx)
  * \return offset of extensions withint `ext' or 0 if extension is not known
  */
 static size_t
-set_extension(struct gl_extensions *ext, const char *name, GLboolean state)
+set_extension(struct gl_extensions *ext, int i, GLboolean state)
 {
    size_t offset;
 
-   offset = name_to_offset(name);
+   offset = i < 0 ? 0 : _mesa_extension_table[i].offset;
    if (offset != 0 && (offset != o(dummy_true) || state != GL_FALSE)) {
       ((GLboolean *) ext)[offset] = state;
    }
@@ -557,62 +207,33 @@ set_extension(struct gl_extensions *ext, const char *name, GLboolean state)
    return offset;
 }
 
-/**
- * \brief Apply the \c MESA_EXTENSION_OVERRIDE environment variable.
- *
- * \c MESA_EXTENSION_OVERRIDE is a space-separated list of extensions to
- * enable or disable. The list is processed thus:
- *    - Enable recognized extension names that are prefixed with '+'.
- *    - Disable recognized extension names that are prefixed with '-'.
- *    - Enable recognized extension names that are not prefixed.
- *    - Collect unrecognized extension names in a new string.
- *
- * \c MESA_EXTENSION_OVERRIDE was previously parsed during
- * _mesa_one_time_init_extension_overrides. We just use the results of that
- * parsing in this function.
- *
- * \return Space-separated list of unrecognized extension names (which must
- *    be freed). Does not return \c NULL.
- */
-static char *
-get_extension_override( struct gl_context *ctx )
-{
-   override_extensions_in_context(ctx);
-
-   if (cant_disable_extensions != NULL) {
-      _mesa_problem(ctx,
-                    "Trying to disable permanently enabled extensions: %s",
-                   cant_disable_extensions);
-   }
-
-   if (extra_extensions == NULL) {
-      return calloc(1, sizeof(char));
-   } else {
-      _mesa_problem(ctx, "Trying to enable unknown extensions: %s",
-                    extra_extensions);
-      return strdup(extra_extensions);
-   }
-}
-
 
 /**
- * \brief Free extra_extensions and cant_disable_extensions strings
+ * \brief Free string pointed by unrecognized_extensions
  *
- * These strings are allocated early during the first context creation by
+ * This string is allocated early during the first context creation by
  * _mesa_one_time_init_extension_overrides.
  */
 static void
 free_unknown_extensions_strings(void)
 {
-   free(extra_extensions);
-   free(cant_disable_extensions);
+   free(unrecognized_extensions.env);
+   for (int i = 0; i < MAX_UNRECOGNIZED_EXTENSIONS; ++i)
+      unrecognized_extensions.names[i] = NULL;
 }
 
 
 /**
- * \brief Initialize extension override tables.
+ * \brief Initialize extension override tables based on \c MESA_EXTENSION_OVERRIDE
  *
  * This should be called one time early during first context initialization.
+
+ * \c MESA_EXTENSION_OVERRIDE is a space-separated list of extensions to
+ * enable or disable. The list is processed thus:
+ *    - Enable recognized extension names that are prefixed with '+'.
+ *    - Disable recognized extension names that are prefixed with '-'.
+ *    - Enable recognized extension names that are not prefixed.
+ *    - Collect unrecognized extension names in a new string.
  */
 void
 _mesa_one_time_init_extension_overrides(void)
@@ -620,10 +241,8 @@ _mesa_one_time_init_extension_overrides(void)
    const char *env_const = getenv("MESA_EXTENSION_OVERRIDE");
    char *env;
    char *ext;
-   int len;
    size_t offset;
-
-   atexit(free_unknown_extensions_strings);
+   unsigned unknown_ext = 0;
 
    memset(&_mesa_extension_override_enables, 0, sizeof(struct gl_extensions));
    memset(&_mesa_extension_override_disables, 0, sizeof(struct gl_extensions));
@@ -632,23 +251,15 @@ _mesa_one_time_init_extension_overrides(void)
       return;
    }
 
-   /* extra_exts: List of unrecognized extensions. */
-   extra_extensions = calloc(ALIGN(strlen(env_const) + 2, 4), sizeof(char));
-   cant_disable_extensions = calloc(ALIGN(strlen(env_const) + 2, 4), sizeof(char));
-
    /* Copy env_const because strtok() is destructive. */
    env = strdup(env_const);
 
-   if (env == NULL || extra_extensions == NULL ||
-           cant_disable_extensions == NULL) {
-       free(env);
-       free(extra_extensions);
-       free(cant_disable_extensions);
-       return;
-   }
+   if (env == NULL)
+      return;
 
    for (ext = strtok(env, " "); ext != NULL; ext = strtok(NULL, " ")) {
       int enable;
+      int i;
       bool recognized;
       switch (ext[0]) {
       case '+':
@@ -664,41 +275,37 @@ _mesa_one_time_init_extension_overrides(void)
          break;
       }
 
-      offset = set_extension(&_mesa_extension_override_enables, ext, enable);
-      if (offset != 0 && (offset != o(dummy_true) || enable != GL_FALSE)) {
-         ((GLboolean *) &_mesa_extension_override_disables)[offset] = !enable;
+      i = name_to_index(ext);
+      offset = set_extension(&_mesa_extension_override_enables, i, enable);
+      offset = set_extension(&_mesa_extension_override_disables, i, !enable);
+      if (offset != 0)
          recognized = true;
-      } else {
+      else
          recognized = false;
-      }
 
-      if (!recognized) {
-         if (enable) {
-            strcat(extra_extensions, ext);
-            strcat(extra_extensions, " ");
-         } else if (offset == o(dummy_true)) {
-            strcat(cant_disable_extensions, ext);
-            strcat(cant_disable_extensions, " ");
+      if (!recognized && enable) {
+         if (unknown_ext >= MAX_UNRECOGNIZED_EXTENSIONS) {
+            static bool warned;
+
+            if (!warned) {
+               warned = true;
+               _mesa_problem(NULL, "Trying to enable too many unknown extension. "
+                                   "Only the first %d will be honoured",
+                                   MAX_UNRECOGNIZED_EXTENSIONS);
+            }
+         } else {
+            unrecognized_extensions.names[unknown_ext] = ext;
+            unknown_ext++;
+            _mesa_problem(NULL, "Trying to enable unknown extension: %s", ext);
          }
       }
    }
 
-   free(env);
-
-   /* Remove trailing space, and free if unused. */
-   len = strlen(extra_extensions);
-   if (len == 0) {
-      free(extra_extensions);
-      extra_extensions = NULL;
-   } else if (extra_extensions[len - 1] == ' ') {
-      extra_extensions[len - 1] = '\0';
-   }
-   len = strlen(cant_disable_extensions);
-   if (len == 0) {
-      free(cant_disable_extensions);
-      cant_disable_extensions = NULL;
-   } else if (cant_disable_extensions[len - 1] == ' ') {
-      cant_disable_extensions[len - 1] = '\0';
+   if (!unknown_ext) {
+      free(env);
+   } else {
+      unrecognized_extensions.env = env;
+      atexit(free_unknown_extensions_strings);
    }
 }
 
@@ -722,26 +329,40 @@ _mesa_init_extensions(struct gl_extensions *extensions)
 
    /* Then, selectively turn default extensions on. */
    extensions->dummy_true = GL_TRUE;
-   extensions->EXT_texture3D = GL_TRUE;
 }
 
 
 typedef unsigned short extension_index;
 
 
+/**
+ * Given an extension enum, return whether or not the extension is supported
+ * dependent on the following factors:
+ * There's driver support and the OpenGL/ES version is at least that
+ * specified in the _mesa_extension_table.
+ */
+static inline bool
+_mesa_extension_supported(const struct gl_context *ctx, extension_index i)
+{
+   const bool *base = (bool *) &ctx->Extensions;
+   const struct mesa_extension *ext = _mesa_extension_table + i;
+
+   return (ctx->Version >= ext->version[ctx->API]) && base[ext->offset];
+}
+
 /**
  * Compare two entries of the extensions table.  Sorts first by year,
  * then by name.
  *
- * Arguments are indices into extension_table.
+ * Arguments are indices into _mesa_extension_table.
  */
 static int
 extension_compare(const void *p1, const void *p2)
 {
    extension_index i1 = * (const extension_index *) p1;
    extension_index i2 = * (const extension_index *) p2;
-   const struct extension *e1 = &extension_table[i1];
-   const struct extension *e2 = &extension_table[i2];
+   const struct mesa_extension *e1 = &_mesa_extension_table[i1];
+   const struct mesa_extension *e2 = &_mesa_extension_table[i2];
    int res;
 
    res = (int)e1->year - (int)e2->year;
@@ -768,18 +389,10 @@ _mesa_make_extension_string(struct gl_context *ctx)
    /* Number of extensions */
    unsigned count;
    /* Indices of the extensions sorted by year */
-   extension_index *extension_indices;
-   /* String of extra extensions. */
-   char *extra_extensions = get_extension_override(ctx);
-   GLboolean *base = (GLboolean *) &ctx->Extensions;
-   const struct extension *i;
+   extension_index extension_indices[MESA_EXTENSION_COUNT];
+   unsigned k;
    unsigned j;
    unsigned maxYear = ~0;
-   unsigned api_set = (1 << ctx->API);
-   if (_mesa_is_gles3(ctx))
-      api_set |= ES3;
-   if (_mesa_is_gles31(ctx))
-      api_set |= ES31;
 
    /* Check if the MESA_EXTENSION_MAX_YEAR env var is set */
    {
@@ -793,41 +406,36 @@ _mesa_make_extension_string(struct gl_context *ctx)
 
    /* Compute length of the extension string. */
    count = 0;
-   for (i = extension_table; i->name != 0; ++i) {
-      if (base[i->offset] &&
-          i->year <= maxYear &&
-          (i->api_set & api_set)) {
+   for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
+      const struct mesa_extension *i = _mesa_extension_table + k;
+
+      if (i->year <= maxYear &&
+          _mesa_extension_supported(ctx, k)) {
         length += strlen(i->name) + 1; /* +1 for space */
         ++count;
       }
    }
-   if (extra_extensions != NULL)
-      length += 1 + strlen(extra_extensions); /* +1 for space */
+   for (k = 0; k < MAX_UNRECOGNIZED_EXTENSIONS; k++)
+      if (unrecognized_extensions.names[k])
+         length += 1 + strlen(unrecognized_extensions.names[k]); /* +1 for space */
 
    exts = calloc(ALIGN(length + 1, 4), sizeof(char));
    if (exts == NULL) {
-      free(extra_extensions);
       return NULL;
    }
 
-   extension_indices = malloc(count * sizeof(extension_index));
-   if (extension_indices == NULL) {
-      free(exts);
-      free(extra_extensions);
-      return NULL;
-   }
-
-   /* Sort extensions in chronological order because certain old applications
-    * (e.g., Quake3 demo) store the extension list in a static size buffer so
-    * chronologically order ensure that the extensions that such applications
-    * expect will fit into that buffer.
+   /* Sort extensions in chronological order because idTech 2/3 games
+    * (e.g., Quake3 demo) store the extension list in a fixed size buffer.
+    * Some cases truncate, while others overflow the buffer. Resulting in
+    * misrendering and crashes, respectively.
+    * Address the former here, while the latter will be addressed by setting
+    * the MESA_EXTENSION_MAX_YEAR environment variable.
     */
    j = 0;
-   for (i = extension_table; i->name != 0; ++i) {
-      if (base[i->offset] &&
-          i->year <= maxYear &&
-          (i->api_set & api_set)) {
-         extension_indices[j++] = i - extension_table;
+   for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
+      if (_mesa_extension_table[k].year <= maxYear &&
+         _mesa_extension_supported(ctx, k)) {
+         extension_indices[j++] = k;
       }
    }
    assert(j == count);
@@ -836,15 +444,16 @@ _mesa_make_extension_string(struct gl_context *ctx)
 
    /* Build the extension string.*/
    for (j = 0; j < count; ++j) {
-      i = &extension_table[extension_indices[j]];
-      assert(base[i->offset] && (i->api_set & api_set));
+      const struct mesa_extension *i = &_mesa_extension_table[extension_indices[j]];
+      assert(_mesa_extension_supported(ctx, extension_indices[j]));
       strcat(exts, i->name);
       strcat(exts, " ");
    }
-   free(extension_indices);
-   if (extra_extensions != 0) {
-      strcat(exts, extra_extensions);
-      free(extra_extensions);
+   for (j = 0; j < MAX_UNRECOGNIZED_EXTENSIONS; j++) {
+      if (unrecognized_extensions.names[j]) {
+         strcat(exts, unrecognized_extensions.names[j]);
+         strcat(exts, " ");
+      }
    }
 
    return (GLubyte *) exts;
@@ -856,23 +465,20 @@ _mesa_make_extension_string(struct gl_context *ctx)
 GLuint
 _mesa_get_extension_count(struct gl_context *ctx)
 {
-   GLboolean *base;
-   const struct extension *i;
-   unsigned api_set = (1 << ctx->API);
-   if (_mesa_is_gles3(ctx))
-      api_set |= ES3;
-   if (_mesa_is_gles31(ctx))
-      api_set |= ES31;
+   unsigned k;
 
    /* only count once */
    if (ctx->Extensions.Count != 0)
       return ctx->Extensions.Count;
 
-   base = (GLboolean *) &ctx->Extensions;
-   for (i = extension_table; i->name != 0; ++i) {
-      if (base[i->offset] && (i->api_set & api_set)) {
+   for (k = 0; k < MESA_EXTENSION_COUNT; ++k) {
+      if (_mesa_extension_supported(ctx, k))
         ctx->Extensions.Count++;
-      }
+   }
+
+   for (k = 0; k < MAX_UNRECOGNIZED_EXTENSIONS; ++k) {
+      if (unrecognized_extensions.names[k])
+         ctx->Extensions.Count++;
    }
    return ctx->Extensions.Count;
 }
@@ -883,25 +489,25 @@ _mesa_get_extension_count(struct gl_context *ctx)
 const GLubyte *
 _mesa_get_enabled_extension(struct gl_context *ctx, GLuint index)
 {
-   const GLboolean *base;
-   size_t n;
-   const struct extension *i;
-   unsigned api_set = (1 << ctx->API);
-   if (_mesa_is_gles3(ctx))
-      api_set |= ES3;
-   if (_mesa_is_gles31(ctx))
-      api_set |= ES31;
-
-   base = (GLboolean*) &ctx->Extensions;
-   n = 0;
-   for (i = extension_table; i->name != 0; ++i) {
-      if (base[i->offset] && (i->api_set & api_set)) {
+   size_t n = 0;
+   unsigned i;
+
+   for (i = 0; i < MESA_EXTENSION_COUNT; ++i) {
+      if (_mesa_extension_supported(ctx, i)) {
          if (n == index)
-            return (const GLubyte*) i->name;
+            return (const GLubyte*) _mesa_extension_table[i].name;
          else
             ++n;
       }
    }
 
+   for (i = 0; i < MAX_UNRECOGNIZED_EXTENSIONS; ++i) {
+      if (unrecognized_extensions.names[i]) {
+         if (n == index)
+            return (const GLubyte*) unrecognized_extensions.names[i];
+         else
+            ++n;
+      }
+   }
    return NULL;
 }