src/mesa/main/version.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2010  VMware, Inc.  All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 #include <stdio.h>
  27 #include "context.h"
  28 #include "imports.h"
  29 #include "mtypes.h"
  30 #include "version.h"
  31 #include "git_sha1.h"
  32
  33 /**
  34  * Scans 'string' to see if it ends with 'ending'.
  35  */
  36 static bool
  37 check_for_ending(const char *string, const char *ending)
  38 {
  39    const size_t len1 = strlen(string);
  40    const size_t len2 = strlen(ending);
  41
  42    if (len2 > len1)
  43       return false;
  44
  45    return strcmp(string + (len1 - len2), ending) == 0;
  46 }
  47
  48 /**
  49  * Returns the gl override data
  50  *
  51  * version > 0 indicates there is an override requested
  52  * fwd_context is only valid if version > 0
  53  */
  54 static void
  55 get_gl_override(gl_api api, int *version, bool *fwd_context,
  56                 bool *compat_context)
  57 {
  58    const char *env_var = (api == API_OPENGL_CORE || api == API_OPENGL_COMPAT)
  59       ? "MESA_GL_VERSION_OVERRIDE" : "MESA_GLES_VERSION_OVERRIDE";
  60    const char *version_str;
  61    int major, minor, n;
  62    static struct override_info {
  63       int version;
  64       bool fc_suffix;
  65       bool compat_suffix;
  66    } override[] = {
  67       { -1, false, false},
  68       { -1, false, false},
  69       { -1, false, false},
  70       { -1, false, false},
  71    };
  72
  73    STATIC_ASSERT(ARRAY_SIZE(override) == API_OPENGL_LAST + 1);
  74
  75    if (api == API_OPENGLES)
  76       goto exit;
  77
  78    if (override[api].version < 0) {
  79       override[api].version = 0;
  80
  81       version_str = getenv(env_var);
  82       if (version_str) {
  83          override[api].fc_suffix = check_for_ending(version_str, "FC");
  84          override[api].compat_suffix = check_for_ending(version_str, "COMPAT");
  85
  86          n = sscanf(version_str, "%u.%u", &major, &minor);
  87          if (n != 2) {
  88             fprintf(stderr, "error: invalid value for %s: %s\n",
  89                     env_var, version_str);
  90             override[api].version = 0;
  91          } else {
  92             override[api].version = major * 10 + minor;
  93
  94             /* There is no such thing as compatibility or forward-compatible for
  95              * OpenGL ES 2.0 or 3.x APIs.
  96              */
  97             if ((override[api].version < 30 && override[api].fc_suffix) ||
  98                 (api == API_OPENGLES2 && (override[api].fc_suffix ||
  99                                           override[api].compat_suffix))) {
 100                fprintf(stderr, "error: invalid value for %s: %s\n",
 101                        env_var, version_str);
 102             }
 103          }
 104       }
 105    }
 106
 107 exit:
 108    *version = override[api].version;
 109    *fwd_context = override[api].fc_suffix;
 110    *compat_context = override[api].compat_suffix;
 111 }
 112
 113 /**
 114  * Builds the Mesa version string.
 115  */
 116 static void
 117 create_version_string(struct gl_context *ctx, const char *prefix)
 118 {
 119    static const int max = 100;
 120
 121    ctx->VersionString = malloc(max);
 122    if (ctx->VersionString) {
 123       _mesa_snprintf(ctx->VersionString, max,
 124                      "%s%u.%u%s Mesa " PACKAGE_VERSION
 125 #ifdef MESA_GIT_SHA1
 126                      " (" MESA_GIT_SHA1 ")"
 127 #endif
 128                      ,
 129                      prefix,
 130                      ctx->Version / 10, ctx->Version % 10,
 131                      (ctx->API == API_OPENGL_CORE) ? " (Core Profile)" : ""
 132                      );
 133    }
 134 }
 135
 136 /**
 137  * Override the context's version and/or API type if the
 138  * environment variable MESA_GL_VERSION_OVERRIDE is set.
 139  *
 140  * Example uses of MESA_GL_VERSION_OVERRIDE:
 141  *
 142  * 2.1: select a compatibility (non-Core) profile with GL version 2.1
 143  * 3.0: select a compatibility (non-Core) profile with GL version 3.0
 144  * 3.0FC: select a Core+Forward Compatible profile with GL version 3.0
 145  * 3.1: select a Core profile with GL version 3.1
 146  * 3.1FC: select a Core+Forward Compatible profile with GL version 3.1
 147  */
 148 bool
 149 _mesa_override_gl_version_contextless(struct gl_constants *consts,
 150                                       gl_api *apiOut, GLuint *versionOut)
 151 {
 152    int version;
 153    bool fwd_context, compat_context;
 154
 155    get_gl_override(*apiOut, &version, &fwd_context, &compat_context);
 156
 157    if (version > 0) {
 158       *versionOut = version;
 159
 160       /* If the API is a desktop API, adjust the context flags.  We may also
 161        * need to modify the API depending on the version.  For example, Mesa
 162        * does not support a GL 3.3 compatibility profile.
 163        */
 164       if (*apiOut == API_OPENGL_CORE || *apiOut == API_OPENGL_COMPAT) {
 165          if (version >= 30 && fwd_context) {
 166             *apiOut = API_OPENGL_CORE;
 167             consts->ContextFlags |= GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
 168          } else if (version >= 31 && !compat_context) {
 169             *apiOut = API_OPENGL_CORE;
 170          } else {
 171             *apiOut = API_OPENGL_COMPAT;
 172          }
 173       }
 174
 175       return true;
 176    }
 177    return false;
 178 }
 179
 180 void
 181 _mesa_override_gl_version(struct gl_context *ctx)
 182 {
 183    if (_mesa_override_gl_version_contextless(&ctx->Const, &ctx->API,
 184                                              &ctx->Version)) {
 185       /* We need to include API in version string for OpenGL ES, otherwise
 186        * application can not detect GLES via glGetString(GL_VERSION) query.
 187        *
 188        * From OpenGL ES 3.2 spec, Page 436:
 189        *
 190        *     "The VERSION string is laid out as follows:
 191        *
 192        *     OpenGL ES N.M vendor-specific information"
 193        *
 194        * From OpenGL 4.5 spec, Page 538:
 195        *
 196        *     "The VERSION and SHADING_LANGUAGE_VERSION strings are laid out as
 197        *     follows:
 198        *
 199        *     <version number><space><vendor-specific information>"
 200        */
 201       create_version_string(ctx, _mesa_is_gles(ctx) ? "OpenGL ES " : "");
 202       ctx->Extensions.Version = ctx->Version;
 203    }
 204 }
 205
 206 /**
 207  * Override the context's GLSL version if the environment variable
 208  * MESA_GLSL_VERSION_OVERRIDE is set. Valid values for
 209  * MESA_GLSL_VERSION_OVERRIDE are integers, such as "130".
 210  */
 211 void
 212 _mesa_override_glsl_version(struct gl_constants *consts)
 213 {
 214    const char *env_var = "MESA_GLSL_VERSION_OVERRIDE";
 215    const char *version;
 216    int n;
 217
 218    version = getenv(env_var);
 219    if (!version) {
 220       return;
 221    }
 222
 223    n = sscanf(version, "%u", &consts->GLSLVersion);
 224    if (n != 1) {
 225       fprintf(stderr, "error: invalid value for %s: %s\n", env_var, version);
 226       return;
 227    }
 228 }
 229
 230 /**
 231  * Examine enabled GL extensions to determine GL version.
 232  */
 233 static GLuint
 234 compute_version(const struct gl_extensions *extensions,
 235                 const struct gl_constants *consts, gl_api api)
 236 {
 237    GLuint major, minor, version;
 238
 239    const bool ver_1_3 = (extensions->ARB_texture_border_clamp &&
 240                          extensions->ARB_texture_cube_map &&
 241                          extensions->ARB_texture_env_combine &&
 242                          extensions->ARB_texture_env_dot3);
 243    const bool ver_1_4 = (ver_1_3 &&
 244                          extensions->ARB_depth_texture &&
 245                          extensions->ARB_shadow &&
 246                          extensions->ARB_texture_env_crossbar &&
 247                          extensions->EXT_blend_color &&
 248                          extensions->EXT_blend_func_separate &&
 249                          extensions->EXT_blend_minmax &&
 250                          extensions->EXT_point_parameters);
 251    const bool ver_1_5 = (ver_1_4 &&
 252                          extensions->ARB_occlusion_query);
 253    const bool ver_2_0 = (ver_1_5 &&
 254                          extensions->ARB_point_sprite &&
 255                          extensions->ARB_vertex_shader &&
 256                          extensions->ARB_fragment_shader &&
 257                          extensions->ARB_texture_non_power_of_two &&
 258                          extensions->EXT_blend_equation_separate &&
 259
 260                          /* Technically, 2.0 requires the functionality of the
 261                           * EXT version.  Enable 2.0 if either extension is
 262                           * available, and assume that a driver that only
 263                           * exposes the ATI extension will fallback to
 264                           * software when necessary.
 265                           */
 266                          (extensions->EXT_stencil_two_side
 267                           || extensions->ATI_separate_stencil));
 268    const bool ver_2_1 = (ver_2_0 &&
 269                          extensions->EXT_pixel_buffer_object &&
 270                          extensions->EXT_texture_sRGB);
 271    const bool ver_3_0 = (ver_2_1 &&
 272                          consts->GLSLVersion >= 130 &&
 273                          (consts->MaxSamples >= 4 || consts->FakeSWMSAA) &&
 274                          (api == API_OPENGL_CORE ||
 275                           extensions->ARB_color_buffer_float) &&
 276                          extensions->ARB_depth_buffer_float &&
 277                          extensions->ARB_half_float_vertex &&
 278                          extensions->ARB_map_buffer_range &&
 279                          extensions->ARB_shader_texture_lod &&
 280                          extensions->ARB_texture_float &&
 281                          extensions->ARB_texture_rg &&
 282                          extensions->ARB_texture_compression_rgtc &&
 283                          extensions->EXT_draw_buffers2 &&
 284                          extensions->ARB_framebuffer_object &&
 285                          extensions->EXT_framebuffer_sRGB &&
 286                          extensions->EXT_packed_float &&
 287                          extensions->EXT_texture_array &&
 288                          extensions->EXT_texture_shared_exponent &&
 289                          extensions->EXT_transform_feedback &&
 290                          extensions->NV_conditional_render);
 291    const bool ver_3_1 = (ver_3_0 &&
 292                          consts->GLSLVersion >= 140 &&
 293                          extensions->ARB_draw_instanced &&
 294                          extensions->ARB_texture_buffer_object &&
 295                          extensions->ARB_uniform_buffer_object &&
 296                          extensions->EXT_texture_snorm &&
 297                          extensions->NV_primitive_restart &&
 298                          extensions->NV_texture_rectangle &&
 299                          consts->Program[MESA_SHADER_VERTEX].MaxTextureImageUnits >= 16);
 300    const bool ver_3_2 = (ver_3_1 &&
 301                          consts->GLSLVersion >= 150 &&
 302                          extensions->ARB_depth_clamp &&
 303                          extensions->ARB_draw_elements_base_vertex &&
 304                          extensions->ARB_fragment_coord_conventions &&
 305                          extensions->EXT_provoking_vertex &&
 306                          extensions->ARB_seamless_cube_map &&
 307                          extensions->ARB_sync &&
 308                          extensions->ARB_texture_multisample &&
 309                          extensions->EXT_vertex_array_bgra);
 310    const bool ver_3_3 = (ver_3_2 &&
 311                          consts->GLSLVersion >= 330 &&
 312                          extensions->ARB_blend_func_extended &&
 313                          extensions->ARB_explicit_attrib_location &&
 314                          extensions->ARB_instanced_arrays &&
 315                          extensions->ARB_occlusion_query2 &&
 316                          extensions->ARB_shader_bit_encoding &&
 317                          extensions->ARB_texture_rgb10_a2ui &&
 318                          extensions->ARB_timer_query &&
 319                          extensions->ARB_vertex_type_2_10_10_10_rev &&
 320                          extensions->EXT_texture_swizzle);
 321    /* ARB_sampler_objects is always enabled in mesa */
 322
 323    const bool ver_4_0 = (ver_3_3 &&
 324                          consts->GLSLVersion >= 400 &&
 325                          extensions->ARB_draw_buffers_blend &&
 326                          extensions->ARB_draw_indirect &&
 327                          extensions->ARB_gpu_shader5 &&
 328                          extensions->ARB_gpu_shader_fp64 &&
 329                          extensions->ARB_sample_shading &&
 330                          extensions->ARB_tessellation_shader &&
 331                          extensions->ARB_texture_buffer_object_rgb32 &&
 332                          extensions->ARB_texture_cube_map_array &&
 333                          extensions->ARB_texture_query_lod &&
 334                          extensions->ARB_transform_feedback2 &&
 335                          extensions->ARB_transform_feedback3);
 336    const bool ver_4_1 = (ver_4_0 &&
 337                          consts->GLSLVersion >= 410 &&
 338                          extensions->ARB_ES2_compatibility &&
 339                          extensions->ARB_shader_precision &&
 340                          extensions->ARB_vertex_attrib_64bit &&
 341                          extensions->ARB_viewport_array);
 342    const bool ver_4_2 = (ver_4_1 &&
 343                          consts->GLSLVersion >= 420 &&
 344                          extensions->ARB_base_instance &&
 345                          extensions->ARB_conservative_depth &&
 346                          extensions->ARB_internalformat_query &&
 347                          extensions->ARB_shader_atomic_counters &&
 348                          extensions->ARB_shader_image_load_store &&
 349                          extensions->ARB_shading_language_420pack &&
 350                          extensions->ARB_shading_language_packing &&
 351                          extensions->ARB_texture_compression_bptc &&
 352                          extensions->ARB_transform_feedback_instanced);
 353    const bool ver_4_3 = (ver_4_2 &&
 354                          consts->GLSLVersion >= 430 &&
 355                          extensions->ARB_ES3_compatibility &&
 356                          extensions->ARB_arrays_of_arrays &&
 357                          extensions->ARB_compute_shader &&
 358                          extensions->ARB_copy_image &&
 359                          extensions->ARB_explicit_uniform_location &&
 360                          extensions->ARB_fragment_layer_viewport &&
 361                          extensions->ARB_framebuffer_no_attachments &&
 362                          extensions->ARB_internalformat_query2 &&
 363                          extensions->ARB_robust_buffer_access_behavior &&
 364                          extensions->ARB_shader_image_size &&
 365                          extensions->ARB_shader_storage_buffer_object &&
 366                          extensions->ARB_stencil_texturing &&
 367                          extensions->ARB_texture_buffer_range &&
 368                          extensions->ARB_texture_query_levels &&
 369                          extensions->ARB_texture_view);
 370    const bool ver_4_4 = (ver_4_3 &&
 371                          consts->GLSLVersion >= 440 &&
 372                          extensions->ARB_buffer_storage &&
 373                          extensions->ARB_clear_texture &&
 374                          extensions->ARB_enhanced_layouts &&
 375                          extensions->ARB_query_buffer_object &&
 376                          extensions->ARB_texture_mirror_clamp_to_edge &&
 377                          extensions->ARB_texture_stencil8 &&
 378                          extensions->ARB_vertex_type_10f_11f_11f_rev);
 379    const bool ver_4_5 = (ver_4_4 &&
 380                          consts->GLSLVersion >= 450 &&
 381                          extensions->ARB_ES3_1_compatibility &&
 382                          extensions->ARB_clip_control &&
 383                          extensions->ARB_conditional_render_inverted &&
 384                          extensions->ARB_cull_distance &&
 385                          extensions->ARB_derivative_control &&
 386                          extensions->ARB_shader_texture_image_samples &&
 387                          extensions->NV_texture_barrier);
 388
 389    if (ver_4_5) {
 390       major = 4;
 391       minor = 5;
 392    }
 393    else if (ver_4_4) {
 394       major = 4;
 395       minor = 4;
 396    }
 397    else if (ver_4_3) {
 398       major = 4;
 399       minor = 3;
 400    }
 401    else if (ver_4_2) {
 402       major = 4;
 403       minor = 2;
 404    }
 405    else if (ver_4_1) {
 406       major = 4;
 407       minor = 1;
 408    }
 409    else if (ver_4_0) {
 410       major = 4;
 411       minor = 0;
 412    }
 413    else if (ver_3_3) {
 414       major = 3;
 415       minor = 3;
 416    }
 417    else if (ver_3_2) {
 418       major = 3;
 419       minor = 2;
 420    }
 421    else if (ver_3_1) {
 422       major = 3;
 423       minor = 1;
 424    }
 425    else if (ver_3_0) {
 426       major = 3;
 427       minor = 0;
 428    }
 429    else if (ver_2_1) {
 430       major = 2;
 431       minor = 1;
 432    }
 433    else if (ver_2_0) {
 434       major = 2;
 435       minor = 0;
 436    }
 437    else if (ver_1_5) {
 438       major = 1;
 439       minor = 5;
 440    }
 441    else if (ver_1_4) {
 442       major = 1;
 443       minor = 4;
 444    }
 445    else if (ver_1_3) {
 446       major = 1;
 447       minor = 3;
 448    }
 449    else {
 450       major = 1;
 451       minor = 2;
 452    }
 453
 454    version = major * 10 + minor;
 455
 456    if (api == API_OPENGL_CORE && version < 31)
 457       return 0;
 458
 459    return version;
 460 }
 461
 462 static GLuint
 463 compute_version_es1(const struct gl_extensions *extensions)
 464 {
 465    /* OpenGL ES 1.0 is derived from OpenGL 1.3 */
 466    const bool ver_1_0 = (extensions->ARB_texture_env_combine &&
 467                          extensions->ARB_texture_env_dot3);
 468    /* OpenGL ES 1.1 is derived from OpenGL 1.5 */
 469    const bool ver_1_1 = (ver_1_0 &&
 470                          extensions->EXT_point_parameters);
 471
 472    if (ver_1_1) {
 473       return 11;
 474    } else if (ver_1_0) {
 475       return 10;
 476    } else {
 477       return 0;
 478    }
 479 }
 480
 481 static GLuint
 482 compute_version_es2(const struct gl_extensions *extensions,
 483                     const struct gl_constants *consts)
 484 {
 485    /* OpenGL ES 2.0 is derived from OpenGL 2.0 */
 486    const bool ver_2_0 = (extensions->ARB_texture_cube_map &&
 487                          extensions->EXT_blend_color &&
 488                          extensions->EXT_blend_func_separate &&
 489                          extensions->EXT_blend_minmax &&
 490                          extensions->ARB_vertex_shader &&
 491                          extensions->ARB_fragment_shader &&
 492                          extensions->ARB_texture_non_power_of_two &&
 493                          extensions->EXT_blend_equation_separate);
 494    /* FINISHME: This list isn't quite right. */
 495    const bool ver_3_0 = (extensions->ARB_half_float_vertex &&
 496                          extensions->ARB_internalformat_query &&
 497                          extensions->ARB_map_buffer_range &&
 498                          extensions->ARB_shader_texture_lod &&
 499                          extensions->ARB_texture_float &&
 500                          extensions->ARB_texture_rg &&
 501                          extensions->ARB_depth_buffer_float &&
 502                          extensions->EXT_draw_buffers2 &&
 503                          /* extensions->ARB_framebuffer_object && */
 504                          extensions->EXT_framebuffer_sRGB &&
 505                          extensions->EXT_packed_float &&
 506                          extensions->EXT_texture_array &&
 507                          extensions->EXT_texture_shared_exponent &&
 508                          extensions->EXT_transform_feedback &&
 509                          extensions->ARB_draw_instanced &&
 510                          extensions->ARB_uniform_buffer_object &&
 511                          extensions->EXT_texture_snorm &&
 512                          extensions->NV_primitive_restart &&
 513                          extensions->OES_depth_texture_cube_map);
 514    const bool es31_compute_shader =
 515       consts->MaxComputeWorkGroupInvocations >= 128;
 516    const bool ver_3_1 = (ver_3_0 &&
 517                          extensions->ARB_arrays_of_arrays &&
 518                          es31_compute_shader &&
 519                          extensions->ARB_draw_indirect &&
 520                          extensions->ARB_explicit_uniform_location &&
 521                          extensions->ARB_framebuffer_no_attachments &&
 522                          extensions->ARB_shader_atomic_counters &&
 523                          extensions->ARB_shader_image_load_store &&
 524                          extensions->ARB_shader_image_size &&
 525                          extensions->ARB_shader_storage_buffer_object &&
 526                          extensions->ARB_shading_language_packing &&
 527                          extensions->ARB_stencil_texturing &&
 528                          extensions->ARB_texture_multisample &&
 529                          extensions->ARB_gpu_shader5 &&
 530                          extensions->EXT_shader_integer_mix);
 531    const bool ver_3_2 = (ver_3_1 &&
 532                          extensions->KHR_blend_equation_advanced &&
 533                          extensions->KHR_robustness &&
 534                          extensions->KHR_texture_compression_astc_ldr &&
 535                          extensions->OES_copy_image &&
 536                          extensions->ARB_draw_buffers_blend &&
 537                          extensions->ARB_draw_elements_base_vertex &&
 538                          extensions->OES_geometry_shader &&
 539                          extensions->OES_primitive_bounding_box &&
 540                          extensions->OES_sample_variables &&
 541                          extensions->ARB_tessellation_shader &&
 542                          extensions->ARB_texture_border_clamp &&
 543                          extensions->OES_texture_buffer &&
 544                          extensions->OES_texture_cube_map_array &&
 545                          extensions->ARB_texture_stencil8);
 546
 547    if (ver_3_2) {
 548       return 32;
 549    } else if (ver_3_1) {
 550       return 31;
 551    } else if (ver_3_0) {
 552       return 30;
 553    } else if (ver_2_0) {
 554       return 20;
 555    } else {
 556       return 0;
 557    }
 558 }
 559
 560 GLuint
 561 _mesa_get_version(const struct gl_extensions *extensions,
 562                   struct gl_constants *consts, gl_api api)
 563 {
 564    switch (api) {
 565    case API_OPENGL_COMPAT:
 566       /* Disable GLSL 1.40 and later for legacy contexts.
 567        * This disallows creation of the GL 3.1 compatibility context. */
 568       if (!consts->AllowHigherCompatVersion) {
 569          if (consts->GLSLVersion > 130) {
 570             consts->GLSLVersion = 130;
 571          }
 572       }
 573       /* fall through */
 574    case API_OPENGL_CORE:
 575       return compute_version(extensions, consts, api);
 576    case API_OPENGLES:
 577       return compute_version_es1(extensions);
 578    case API_OPENGLES2:
 579       return compute_version_es2(extensions, consts);
 580    }
 581    return 0;
 582 }
 583
 584 /**
 585  * Set the context's Version and VersionString fields.
 586  * This should only be called once as part of context initialization
 587  * or to perform version check for GLX_ARB_create_context_profile.
 588  */
 589 void
 590 _mesa_compute_version(struct gl_context *ctx)
 591 {
 592    if (ctx->Version)
 593       return;
 594
 595    ctx->Version = _mesa_get_version(&ctx->Extensions, &ctx->Const, ctx->API);
 596    ctx->Extensions.Version = ctx->Version;
 597
 598    /* Make sure that the GLSL version lines up with the GL version. In some
 599     * cases it can be too high, e.g. if an extension is missing.
 600     */
 601    if (ctx->API == API_OPENGL_CORE) {
 602       switch (ctx->Version) {
 603       case 31:
 604          ctx->Const.GLSLVersion = 140;
 605          break;
 606       case 32:
 607          ctx->Const.GLSLVersion = 150;
 608          break;
 609       default:
 610          ctx->Const.GLSLVersion = ctx->Version * 10;
 611          break;
 612       }
 613    }
 614
 615    switch (ctx->API) {
 616    case API_OPENGL_COMPAT:
 617    case API_OPENGL_CORE:
 618       create_version_string(ctx, "");
 619       break;
 620
 621    case API_OPENGLES:
 622       if (!ctx->Version) {
 623          _mesa_problem(ctx, "Incomplete OpenGL ES 1.0 support.");
 624          return;
 625       }
 626       create_version_string(ctx, "OpenGL ES-CM ");
 627       break;
 628
 629    case API_OPENGLES2:
 630       if (!ctx->Version) {
 631          _mesa_problem(ctx, "Incomplete OpenGL ES 2.0 support.");
 632          return;
 633       }
 634       create_version_string(ctx, "OpenGL ES ");
 635       break;
 636    }
 637 }