Mesa (master): glsl: Refactor #version validation to be more future-proof.

[Kenneth Graunke]

Module: Mesa
Branch: master
Commit: 3a90dc22d1c74e8719c95221f15043e7f3e69286
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3a90dc22d1c74e8719c95221f15043e7f3e69286

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Tue Jul 31 01:28:35 2012 -0700

glsl: Refactor #version validation to be more future-proof.

The previous implementation required a flag in _mesa_glsl_parse_state
and line of code to initialize it for every version of the shading
language we intend to support.  As we look to add 150, 330, 400, 410,
420, and beyond, this gets rather unwieldy.

This patch retains the switch statement (to reject, say, #version 111),
but removes all the bits.  Code to check for ctx->API == API_OPENGL_CORE
could easily be added to the 110 and 120 cases to reject those.

v2: Use _mesa_is_desktop_gl to preserve the existing behavior in the
    presence of the new API_OPENGL_CORE enumeration.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Eric Anholt <eric at anholt.net> [v1]

---

 src/glsl/glsl_parser.yy         |   23 +++++++++++++++--------
 src/glsl/glsl_parser_extras.cpp |   14 +-------------
 src/glsl/glsl_parser_extras.h   |   17 -----------------
 3 files changed, 16 insertions(+), 38 deletions(-)

diff --git a/src/glsl/glsl_parser.yy b/src/glsl/glsl_parser.yy
index 9873934..d44ec50 100644
--- a/src/glsl/glsl_parser.yy
+++ b/src/glsl/glsl_parser.yy
@@ -29,6 +29,7 @@
 #include "ast.h"
 #include "glsl_parser_extras.h"
 #include "glsl_types.h"
+#include "main/context.h"
 
 #define YYLEX_PARAM state->scanner
 
@@ -259,19 +260,25 @@ version_statement:
 	   switch ($2) {
 	   case 100:
 	      state->es_shader = true;
-	      supported = state->Const.GLSL_100ES;
+	      supported = state->ctx->API == API_OPENGLES2 ||
+		          state->ctx->Extensions.ARB_ES2_compatibility;
 	      break;
 	   case 110:
-	      supported = state->Const.GLSL_110;
-	      break;
 	   case 120:
-	      supported = state->Const.GLSL_120;
-	      break;
+	      /* FINISHME: Once the OpenGL 3.0 'forward compatible' context or
+	       * the OpenGL 3.2 Core context is supported, this logic will need
+	       * change.  Older versions of GLSL are no longer supported
+	       * outside the compatibility contexts of 3.x.
+	       */
 	   case 130:
-	      supported = state->Const.GLSL_130;
-	      break;
 	   case 140:
-	      supported = state->Const.GLSL_140;
+	   case 150:
+	   case 330:
+	   case 400:
+	   case 410:
+	   case 420:
+	      supported = _mesa_is_desktop_gl(state->ctx) &&
+			  ((unsigned) $2) <= state->ctx->Const.GLSLVersion;
 	      break;
 	   default:
 	      supported = false;
diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
index 7a9b221..4e1f332 100644
--- a/src/glsl/glsl_parser_extras.cpp
+++ b/src/glsl/glsl_parser_extras.cpp
@@ -85,23 +85,11 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
 
    this->Const.MaxDrawBuffers = ctx->Const.MaxDrawBuffers;
 
-   /* Note: Once the OpenGL 3.0 'forward compatible' context or the OpenGL 3.2
-    * Core context is supported, this logic will need change.  Older versions of
-    * GLSL are no longer supported outside the compatibility contexts of 3.x.
-    */
-   this->Const.GLSL_100ES = (ctx->API == API_OPENGLES2)
-      || ctx->Extensions.ARB_ES2_compatibility;
-   bool is_desktop_gl = _mesa_is_desktop_gl(ctx);
-   this->Const.GLSL_110 = is_desktop_gl;
-   this->Const.GLSL_120 = is_desktop_gl && (ctx->Const.GLSLVersion >= 120);
-   this->Const.GLSL_130 = is_desktop_gl && (ctx->Const.GLSLVersion >= 130);
-   this->Const.GLSL_140 = is_desktop_gl && (ctx->Const.GLSLVersion >= 140);
-
    const unsigned lowest_version =
       (ctx->API == API_OPENGLES2) || ctx->Extensions.ARB_ES2_compatibility
       ? 100 : 110;
    const unsigned highest_version =
-      is_desktop_gl ? ctx->Const.GLSLVersion : 100;
+      _mesa_is_desktop_gl(ctx) ? ctx->Const.GLSLVersion : 100;
    char *supported = ralloc_strdup(this, "");
 
    for (unsigned ver = lowest_version; ver <= highest_version; ver += 10) {
diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
index fc5d11c..bdb5b67 100644
--- a/src/glsl/glsl_parser_extras.h
+++ b/src/glsl/glsl_parser_extras.h
@@ -122,23 +122,6 @@ struct _mesa_glsl_parse_state {
 
       /* ARB_draw_buffers */
       unsigned MaxDrawBuffers;
-
-      /**
-       * Set of GLSL versions supported by the current context
-       *
-       * Knowing that version X is supported doesn't mean that versions before
-       * X are also supported.  Version 1.00 is only supported in an ES2
-       * context or when GL_ARB_ES2_compatibility is supported.  In an OpenGL
-       * 3.0 "forward compatible" context, GLSL 1.10 and 1.20 are \b not
-       * supported.
-       */
-      /*@{*/
-      unsigned GLSL_100ES:1;
-      unsigned GLSL_110:1;
-      unsigned GLSL_120:1;
-      unsigned GLSL_130:1;
-      unsigned GLSL_140:1;
-      /*@}*/
    } Const;
 
    /**