glsl: Add new GLSL 1.50 constants.

This patch populates the following built-in GLSL 1.50 variables based
on constants stored in ctx->Const:

- gl_MaxVertexOutputComponents
- gl_MaxGeometryInputComponents
- gl_MaxGeometryOutputComponents
- gl_MaxFragmentInputComponents
- gl_MaxGeometryTextureImageUnits
- gl_MaxGeometryOutputVertices
- gl_MaxGeometryTotalOutputComponents
- gl_MaxGeometryUniformComponents
- gl_MaxGeometryVaryingComponents

On i965/gen7, fixes all Piglit tests in "spec/glsl-1.50/built-in
constants/*" except for gl_MaxCombinedTextureImageUnits and
gl_MaxGeometryUniformComponents.

Reviewed-by: Matt Turner <mattst88@gmail.com>

src/glsl/builtin_variables.cpp

@@ -583,6 +583,37 @@ builtin_variable_generator::generate_constants()
       add_const("gl_MaxVaryingComponents", state->ctx->Const.MaxVarying * 4);
    }
 
+   if (state->is_version(150, 0)) {
+      add_const("gl_MaxVertexOutputComponents",
+                state->Const.MaxVertexOutputComponents);
+      add_const("gl_MaxGeometryInputComponents",
+                state->Const.MaxGeometryInputComponents);
+      add_const("gl_MaxGeometryOutputComponents",
+                state->Const.MaxGeometryOutputComponents);
+      add_const("gl_MaxFragmentInputComponents",
+                state->Const.MaxFragmentInputComponents);
+      add_const("gl_MaxGeometryTextureImageUnits",
+                state->Const.MaxGeometryTextureImageUnits);
+      add_const("gl_MaxGeometryOutputVertices",
+                state->Const.MaxGeometryOutputVertices);
+      add_const("gl_MaxGeometryTotalOutputComponents",
+                state->Const.MaxGeometryTotalOutputComponents);
+      add_const("gl_MaxGeometryUniformComponents",
+                state->Const.MaxGeometryUniformComponents);
+
+      /* Note: the GLSL 1.50-4.40 specs require
+       * gl_MaxGeometryVaryingComponents to be present, and to be at least 64.
+       * But they do not define what it means (and there does not appear to be
+       * any corresponding constant in the GL specs).  However,
+       * ARB_geometry_shader4 defines MAX_GEOMETRY_VARYING_COMPONENTS_ARB to
+       * be the maximum number of components available for use as geometry
+       * outputs.  So we assume this is a synonym for
+       * gl_MaxGeometryOutputComponents.
+       */
+      add_const("gl_MaxGeometryVaryingComponents",
+                state->Const.MaxGeometryOutputComponents);
+   }
+
    if (compatibility) {
       /* Note: gl_MaxLights stopped being listed as an explicit constant in
        * GLSL 1.30, however it continues to be referred to (as a minimum size

src/glsl/glsl_parser_extras.cpp

@@ -108,6 +108,16 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
 
    this->Const.MaxDrawBuffers = ctx->Const.MaxDrawBuffers;
 
+   /* 1.50 constants */
+   this->Const.MaxVertexOutputComponents = ctx->Const.VertexProgram.MaxOutputComponents;
+   this->Const.MaxGeometryInputComponents = ctx->Const.GeometryProgram.MaxInputComponents;
+   this->Const.MaxGeometryOutputComponents = ctx->Const.GeometryProgram.MaxOutputComponents;
+   this->Const.MaxFragmentInputComponents = ctx->Const.FragmentProgram.MaxInputComponents;
+   this->Const.MaxGeometryTextureImageUnits = ctx->Const.GeometryProgram.MaxTextureImageUnits;
+   this->Const.MaxGeometryOutputVertices = ctx->Const.MaxGeometryOutputVertices;
+   this->Const.MaxGeometryTotalOutputComponents = ctx->Const.MaxGeometryTotalOutputComponents;
+   this->Const.MaxGeometryUniformComponents = ctx->Const.GeometryProgram.MaxUniformComponents;
+
    this->current_function = NULL;
    this->toplevel_ir = NULL;
    this->found_return = false;

src/glsl/glsl_parser_extras.h

@@ -219,6 +219,16 @@ struct _mesa_glsl_parse_state {
       /* 3.00 ES */
       int MinProgramTexelOffset;
       int MaxProgramTexelOffset;
+
+      /* 1.50 */
+      unsigned MaxVertexOutputComponents;
+      unsigned MaxGeometryInputComponents;
+      unsigned MaxGeometryOutputComponents;
+      unsigned MaxFragmentInputComponents;
+      unsigned MaxGeometryTextureImageUnits;
+      unsigned MaxGeometryOutputVertices;
+      unsigned MaxGeometryTotalOutputComponents;
+      unsigned MaxGeometryUniformComponents;
    } Const;
 
    /**