mesa: don't advertise bogus GL_ARB_shading_language_120 extension

Instead of using the invalid GL_ARB_shading_language_120 extension to
determine the GLSL version, use a new ctx->Const.GLSLVersion field.
Updated the intel and r600 drivers, but untested.

See fd.o bug 29910

NOTE: This is a candidate for the 7.9 branch (but let's wait and see if
there's any regressions).

src/mesa/drivers/dri/i965/brw_context.c

@@ -42,6 +42,12 @@
 #include "tnl/t_pipeline.h"
 
 
+static const struct dri_extension gl_21_extension[] = {
+  {"GL_VERSION_2_1", GL_VERSION_2_1_functions },
+};
+
+
+
 /***************************************
  * Mesa's Driver Functions
  ***************************************/
@@ -88,6 +94,8 @@ GLboolean brwCreateContext( int api,
 
    TNL_CONTEXT(ctx)->Driver.RunPipeline = _tnl_run_pipeline;
 
+   ctx->Const.GLSLVersion = 120;
+
    ctx->Const.MaxDrawBuffers = BRW_MAX_DRAW_BUFFERS;
    ctx->Const.MaxTextureImageUnits = BRW_MAX_TEX_UNIT;
    ctx->Const.MaxTextureCoordUnits = 8; /* Mesa limit */
@@ -152,6 +160,8 @@ GLboolean brwCreateContext( int api,
       MIN2(ctx->Const.FragmentProgram.MaxNativeParameters,
 	   ctx->Const.FragmentProgram.MaxEnvParams);
 
+   driInitExtensions(ctx, gl_21_extension, GL_TRUE);
+
    if (intel->is_g4x || intel->gen >= 5) {
       brw->CMD_VF_STATISTICS = CMD_VF_STATISTICS_GM45;
       brw->CMD_PIPELINE_SELECT = CMD_PIPELINE_SELECT_GM45;

src/mesa/drivers/dri/intel/intel_extensions.c

@@ -89,7 +89,6 @@ static const struct dri_extension card_extensions[] = {
    { "GL_ARB_point_sprite",               NULL },
    { "GL_ARB_shader_objects",             GL_ARB_shader_objects_functions },
    { "GL_ARB_shading_language_100",       GL_VERSION_2_0_functions },
-   { "GL_ARB_shading_language_120",       GL_VERSION_2_1_functions },
    { "GL_ARB_sync",                       GL_ARB_sync_functions },
    { "GL_ARB_texture_border_clamp",       NULL },
    { "GL_ARB_texture_cube_map",           NULL },

src/mesa/drivers/dri/r600/r600_context.c

@@ -166,7 +166,6 @@ static const struct dri_extension mm_extensions[] = {
 static const struct dri_extension gl_20_extension[] = {
 #ifdef R600_ENABLE_GLSL_TEST
     {"GL_ARB_shading_language_100",			GL_VERSION_2_0_functions },
-    {"GL_ARB_shading_language_120",			GL_VERSION_2_1_functions },
 #else
   {"GL_VERSION_2_0",			GL_VERSION_2_0_functions },
 #endif /* R600_ENABLE_GLSL_TEST */
@@ -266,6 +265,8 @@ static void r600InitConstValues(GLcontext *ctx, radeonScreenPtr screen)
         r700->bShaderUseMemConstant = GL_FALSE;
     }
 
+        ctx->Const.GLSLVersion = 120;
+
 	ctx->Const.MaxTextureImageUnits = 16;
 	/* 8 per clause on r6xx, 16 on r7xx
 	 * but I think mesa only supports 8 at the moment

src/mesa/main/context.c

@@ -597,6 +597,21 @@ _mesa_init_constants(GLcontext *ctx)
    ctx->Const.MaxVarying = MAX_VARYING;
 #endif
 
+   /* Shading language version */
+   if (ctx->API == API_OPENGL) {
+#if FEATURE_ARB_shading_language_120
+      ctx->Const.GLSLVersion = 120;
+#else
+      ctx->Const.GLSLVersion = 110;
+#endif
+   }
+   else if (ctx->API == API_OPENGLES2) {
+      ctx->Const.GLSLVersion = 100;
+   }
+   else if (ctx->API == API_OPENGLES) {
+      ctx->Const.GLSLVersion = 0; /* GLSL not supported */
+   }
+
    /* GL_ARB_framebuffer_object */
    ctx->Const.MaxSamples = 0;
 

src/mesa/main/extensions.c

@@ -77,7 +77,6 @@ static const struct {
    { OFF, "GL_ARB_seamless_cube_map",          F(ARB_seamless_cube_map) },
    { OFF, "GL_ARB_shader_objects",             F(ARB_shader_objects) },
    { OFF, "GL_ARB_shading_language_100",       F(ARB_shading_language_100) },
-   { OFF, "GL_ARB_shading_language_120",       F(ARB_shading_language_120) },
    { OFF, "GL_ARB_shadow",                     F(ARB_shadow) },
    { OFF, "GL_ARB_shadow_ambient",             F(ARB_shadow_ambient) },
    { OFF, "GL_ARB_sync",                       F(ARB_sync) },
@@ -268,9 +267,6 @@ _mesa_enable_sw_extensions(GLcontext *ctx)
 #endif
 #if FEATURE_ARB_shading_language_100
    ctx->Extensions.ARB_shading_language_100 = GL_TRUE;
-#endif
-#if FEATURE_ARB_shading_language_120
-   ctx->Extensions.ARB_shading_language_120 = GL_TRUE;
 #endif
    ctx->Extensions.ARB_shadow = GL_TRUE;
    ctx->Extensions.ARB_shadow_ambient = GL_TRUE;
@@ -513,9 +509,6 @@ _mesa_enable_2_1_extensions(GLcontext *ctx)
 #if FEATURE_EXT_texture_sRGB
    ctx->Extensions.EXT_texture_sRGB = GL_TRUE;
 #endif
-#if FEATURE_ARB_shading_language_120
-   ctx->Extensions.ARB_shading_language_120 = GL_TRUE;
-#endif
 }
 
 

src/mesa/main/getstring.c

@@ -30,26 +30,42 @@
 #include "enums.h"
 #include "extensions.h"
 
+
+/**
+ * Return the string for a glGetString(GL_SHADING_LANGUAGE_VERSION) query.
+ */
 static const GLubyte *
 shading_language_version(GLcontext *ctx)
 {
    switch (ctx->API) {
-#if FEATURE_ARB_shading_language_100
    case API_OPENGL:
-      if (ctx->Extensions.ARB_shading_language_120)
+      if (!ctx->Extensions.ARB_shader_objects) {
-	 return (const GLubyte *) "1.20";
+         _mesa_error(ctx, GL_INVALID_ENUM, "glGetString");
-      else if (ctx->Extensions.ARB_shading_language_100)
+         return (const GLubyte *) 0;
+      }
+
+      switch (ctx->Const.GLSLVersion) {
+      case 110:
          return (const GLubyte *) "1.10";
-      goto error;
+      case 120:
-#endif
+         return (const GLubyte *) "1.20";
+      case 130:
+         return (const GLubyte *) "1.30";
+      default:
+         _mesa_problem(ctx,
+                       "Invalid GLSL version in shading_language_version()");
+         return (const GLubyte *) 0;
+      }
+      break;
 
    case API_OPENGLES2:
       return (const GLubyte *) "OpenGL ES GLSL ES 1.0.16";
 
    case API_OPENGLES:
+      /* fall-through */
+
    default:
-   error:
+      _mesa_problem(ctx, "Unexpected API value in shading_language_version()");
-      _mesa_error( ctx, GL_INVALID_ENUM, "glGetString" );
       return (const GLubyte *) 0;
    }
 }

src/mesa/main/mtypes.h

@@ -2608,6 +2608,8 @@ struct gl_constants
 
    GLuint MaxVarying;  /**< Number of float[4] varying parameters */
 
+   GLuint GLSLVersion;  /**< GLSL version supported (ex: 120 = 1.20) */
+
    /** Which texture units support GL_ATI_envmap_bumpmap as targets */
    GLbitfield SupportedBumpUnits;
 
@@ -2668,7 +2670,6 @@ struct gl_extensions
    GLboolean ARB_seamless_cube_map;
    GLboolean ARB_shader_objects;
    GLboolean ARB_shading_language_100;
-   GLboolean ARB_shading_language_120;
    GLboolean ARB_shadow;
    GLboolean ARB_shadow_ambient;
    GLboolean ARB_sync;

src/mesa/main/version.c

@@ -84,7 +84,7 @@ compute_version(GLcontext *ctx)
 			      (ctx->Extensions.EXT_stencil_two_side
 			       || ctx->Extensions.ATI_separate_stencil));
    const GLboolean ver_2_1 = (ver_2_0 &&
-                              ctx->Extensions.ARB_shading_language_120 &&
+                              ctx->Const.GLSLVersion >= 120 &&
                               ctx->Extensions.EXT_pixel_buffer_object &&
                               ctx->Extensions.EXT_texture_sRGB);
    const GLboolean ver_3_0 = (ver_2_1 &&

src/mesa/state_tracker/st_extensions.c

@@ -186,6 +186,11 @@ void st_init_limits(struct st_context *st)
     * attributes) supported by a driver. */
    c->MaxVarying = screen->get_shader_param(screen, PIPE_SHADER_FRAGMENT, PIPE_SHADER_CAP_MAX_INPUTS) - 2;
    c->MaxVarying = MIN2(c->MaxVarying, MAX_VARYING);
+
+   /* XXX we'll need a better query here someday */
+   if (screen->get_param(screen, PIPE_CAP_GLSL)) {
+      c->GLSLVersion = 120;
+   }
 }
 
 
@@ -285,7 +290,6 @@ void st_init_extensions(struct st_context *st)
       ctx->Extensions.ARB_vertex_shader = GL_TRUE;
       ctx->Extensions.ARB_shader_objects = GL_TRUE;
       ctx->Extensions.ARB_shading_language_100 = GL_TRUE;
-      ctx->Extensions.ARB_shading_language_120 = GL_TRUE;
    }
 
    if (screen->get_param(screen, PIPE_CAP_TEXTURE_MIRROR_REPEAT) > 0) {