Mesa (7.10): glsl: Refactor AST-to-HIR code handling variable redeclarations

[Ian Romanick]

Module: Mesa
Branch: 7.10
Commit: f0231a44b91c73795cb5e689ebe92ac5e82f1f78
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f0231a44b91c73795cb5e689ebe92ac5e82f1f78

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Fri Mar  4 15:28:40 2011 -0800

glsl: Refactor AST-to-HIR code handling variable redeclarations

Some significant edits were made to this patch during cherry picking.
There some fairly major conflicts due to GLSL 1.30 features and
extensions added in master that do not exist in the 7.10 branch.

(cherry picked from commit 8e6cb9fe51a2237e51b47198eb7d46b14ad288b5)

---

 src/glsl/ast_to_hir.cpp |  144 +++++++++++++++++++++++++++--------------------
 1 files changed, 82 insertions(+), 62 deletions(-)

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index c26fad3..a05b4cf 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -2017,6 +2017,86 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual,
    }
 }
 
+/**
+ * Get the variable that is being redeclared by this declaration
+ *
+ * Semantic checks to verify the validity of the redeclaration are also
+ * performed.  If semantic checks fail, compilation error will be emitted via
+ * \c _mesa_glsl_error, but a non-\c NULL pointer will still be returned.
+ *
+ * \returns
+ * A pointer to an existing variable in the current scope if the declaration
+ * is a redeclaration, \c NULL otherwise.
+ */
+ir_variable *
+get_variable_being_redeclared(ir_variable *var, ast_declaration *decl,
+			      struct _mesa_glsl_parse_state *state)
+{
+   /* Check if this declaration is actually a re-declaration, either to
+    * resize an array or add qualifiers to an existing variable.
+    *
+    * This is allowed for variables in the current scope, or when at
+    * global scope (for built-ins in the implicit outer scope).
+    */
+   ir_variable *earlier = state->symbols->get_variable(decl->identifier);
+   if (earlier == NULL ||
+       (state->current_function != NULL &&
+	!state->symbols->name_declared_this_scope(decl->identifier))) {
+      return NULL;
+   }
+
+
+   YYLTYPE loc = decl->get_location();
+
+   /* From page 24 (page 30 of the PDF) of the GLSL 1.50 spec,
+    *
+    * "It is legal to declare an array without a size and then
+    *  later re-declare the same name as an array of the same
+    *  type and specify a size."
+    */
+   if ((earlier->type->array_size() == 0)
+       && var->type->is_array()
+       && (var->type->element_type() == earlier->type->element_type())) {
+      /* FINISHME: This doesn't match the qualifiers on the two
+       * FINISHME: declarations.  It's not 100% clear whether this is
+       * FINISHME: required or not.
+       */
+
+      /* From page 54 (page 60 of the PDF) of the GLSL 1.20 spec:
+       *
+       *     "The size [of gl_TexCoord] can be at most
+       *     gl_MaxTextureCoords."
+       */
+      const unsigned size = unsigned(var->type->array_size());
+      if ((strcmp("gl_TexCoord", var->name) == 0)
+	  && (size > state->Const.MaxTextureCoords)) {
+	 _mesa_glsl_error(& loc, state, "`gl_TexCoord' array size cannot "
+			  "be larger than gl_MaxTextureCoords (%u)\n",
+			  state->Const.MaxTextureCoords);
+      } else if ((size > 0) && (size <= earlier->max_array_access)) {
+	 _mesa_glsl_error(& loc, state, "array size must be > %u due to "
+			  "previous access",
+			  earlier->max_array_access);
+      }
+
+      earlier->type = var->type;
+      delete var;
+      var = NULL;
+   } else if (state->ARB_fragment_coord_conventions_enable
+	      && strcmp(var->name, "gl_FragCoord") == 0
+	      && earlier->type == var->type
+	      && earlier->mode == var->mode) {
+      /* Allow redeclaration of gl_FragCoord for ARB_fcc layout
+       * qualifiers.
+       */
+      earlier->origin_upper_left = var->origin_upper_left;
+      earlier->pixel_center_integer = var->pixel_center_integer;
+   } else {
+      _mesa_glsl_error(&loc, state, "`%s' redeclared", decl->identifier);
+   }
+
+   return earlier;
+}
 
 /**
  * Generate the IR for an initializer in a variable declaration
@@ -2448,68 +2528,8 @@ ast_declarator_list::hir(exec_list *instructions,
 			  decl->identifier);
       }
 
-      /* Check if this declaration is actually a re-declaration, either to
-       * resize an array or add qualifiers to an existing variable.
-       *
-       * This is allowed for variables in the current scope, or when at
-       * global scope (for built-ins in the implicit outer scope).
-       */
-      ir_variable *earlier = state->symbols->get_variable(decl->identifier);
-      if (earlier != NULL && (state->current_function == NULL ||
-	  state->symbols->name_declared_this_scope(decl->identifier))) {
-
-	 /* From page 24 (page 30 of the PDF) of the GLSL 1.50 spec,
-	  *
-	  * "It is legal to declare an array without a size and then
-	  *  later re-declare the same name as an array of the same
-	  *  type and specify a size."
-	  */
-	 if ((earlier->type->array_size() == 0)
-	     && var->type->is_array()
-	     && (var->type->element_type() == earlier->type->element_type())) {
-	    /* FINISHME: This doesn't match the qualifiers on the two
-	     * FINISHME: declarations.  It's not 100% clear whether this is
-	     * FINISHME: required or not.
-	     */
-
-	    /* From page 54 (page 60 of the PDF) of the GLSL 1.20 spec:
-	     *
-	     *     "The size [of gl_TexCoord] can be at most
-	     *     gl_MaxTextureCoords."
-	     */
-	    const unsigned size = unsigned(var->type->array_size());
-	    if ((strcmp("gl_TexCoord", var->name) == 0)
-		&& (size > state->Const.MaxTextureCoords)) {
-	       YYLTYPE loc = this->get_location();
-
-	       _mesa_glsl_error(& loc, state, "`gl_TexCoord' array size cannot "
-				"be larger than gl_MaxTextureCoords (%u)\n",
-				state->Const.MaxTextureCoords);
-	    } else if ((size > 0) && (size <= earlier->max_array_access)) {
-	       YYLTYPE loc = this->get_location();
-
-	       _mesa_glsl_error(& loc, state, "array size must be > %u due to "
-				"previous access",
-				earlier->max_array_access);
-	    }
-
-	    earlier->type = var->type;
-	    delete var;
-	    var = NULL;
-	 } else if (state->ARB_fragment_coord_conventions_enable
-		    && strcmp(var->name, "gl_FragCoord") == 0
-		    && earlier->type == var->type
-		    && earlier->mode == var->mode) {
-	    /* Allow redeclaration of gl_FragCoord for ARB_fcc layout
-	     * qualifiers.
-	     */
-	    earlier->origin_upper_left = var->origin_upper_left;
-	    earlier->pixel_center_integer = var->pixel_center_integer;
-	 } else {
-	    YYLTYPE loc = this->get_location();
-	    _mesa_glsl_error(&loc, state, "`%s' redeclared", decl->identifier);
-	 }
-
+      ir_variable *earlier = get_variable_being_redeclared(var, decl, state);
+      if (earlier != NULL) {
 	 continue;
       }