glsl: Add support for default layout qualifiers for uniforms.

I ended up having to add rallocing of the ast_type_qualifier in order
to avoid pulling in ast.h for glsl_parser_extras.h, because I wanted
to track an ast_type_qualifier in the state.

Fixes piglit ARB_uniform_buffer_object/row-major.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/glsl/ast.h

@@ -338,6 +338,25 @@ enum {
 };
 
 struct ast_type_qualifier {
+   /* Callers of this ralloc-based new need not call delete. It's
+    * easier to just ralloc_free 'ctx' (or any of its ancestors). */
+   static void* operator new(size_t size, void *ctx)
+   {
+      void *node;
+
+      node = rzalloc_size(ctx, size);
+      assert(node != NULL);
+
+      return node;
+   }
+
+   /* If the user *does* call delete, that's OK, we will just
+    * ralloc_free in that case. */
+   static void operator delete(void *table)
+   {
+      ralloc_free(table);
+   }
+
    union {
       struct {
 	 unsigned invariant:1;
@@ -424,6 +443,10 @@ struct ast_type_qualifier {
     * returned string is undefined but not null.
     */
    const char *interpolation_string() const;
+
+   bool merge_qualifier(YYLTYPE *loc,
+			_mesa_glsl_parse_state *state,
+			ast_type_qualifier q);
 };
 
 class ast_declarator_list;

src/glsl/ast_type.cpp

@@ -71,3 +71,48 @@ ast_type_qualifier::interpolation_string() const
    else
       return NULL;
 }
+
+bool
+ast_type_qualifier::merge_qualifier(YYLTYPE *loc,
+				    _mesa_glsl_parse_state *state,
+				    ast_type_qualifier q)
+{
+   ast_type_qualifier ubo_mat_mask;
+   ubo_mat_mask.flags.i = 0;
+   ubo_mat_mask.flags.q.row_major = 1;
+   ubo_mat_mask.flags.q.column_major = 1;
+
+   ast_type_qualifier ubo_layout_mask;
+   ubo_layout_mask.flags.i = 0;
+   ubo_layout_mask.flags.q.std140 = 1;
+   ubo_layout_mask.flags.q.packed = 1;
+   ubo_layout_mask.flags.q.shared = 1;
+
+   /* Uniform block layout qualifiers get to overwrite each
+    * other (rightmost having priority), while all other
+    * qualifiers currently don't allow duplicates.
+    */
+
+   if ((this->flags.i & q.flags.i & ~(ubo_mat_mask.flags.i |
+				      ubo_layout_mask.flags.i)) != 0) {
+      _mesa_glsl_error(loc, state,
+		       "duplicate layout qualifiers used\n");
+      return false;
+   }
+
+   if ((q.flags.i & ubo_mat_mask.flags.i) != 0)
+      this->flags.i &= ~ubo_mat_mask.flags.i;
+   if ((q.flags.i & ubo_layout_mask.flags.i) != 0)
+      this->flags.i &= ~ubo_layout_mask.flags.i;
+
+   this->flags.i |= q.flags.i;
+
+   if (q.flags.q.explicit_location)
+      this->location = q.location;
+
+   if (q.flags.q.explicit_index)
+      this->index = q.index;
+
+   return true;
+}
+

src/glsl/glsl_parser.yy

@@ -1113,42 +1113,10 @@ layout_qualifier_id_list:
 	layout_qualifier_id
 	| layout_qualifier_id_list ',' layout_qualifier_id
 	{
-	   ast_type_qualifier ubo_mat_mask;
+	   $$ = $1;
-	   ubo_mat_mask.flags.i = 0;
+	   if (!$$.merge_qualifier(& @3, state, $3)) {
-	   ubo_mat_mask.flags.q.row_major = 1;
-	   ubo_mat_mask.flags.q.column_major = 1;
-
-	   ast_type_qualifier ubo_layout_mask;
-	   ubo_layout_mask.flags.i = 0;
-	   ubo_layout_mask.flags.q.std140 = 1;
-	   ubo_layout_mask.flags.q.packed = 1;
-	   ubo_layout_mask.flags.q.shared = 1;
-
-	   /* Uniform block layout qualifiers get to overwrite each
-	    * other (rightmost having priority), while all other
-	    * qualifiers currently don't allow duplicates.
-	    */
-	   if (($1.flags.i & $3.flags.i & ~(ubo_mat_mask.flags.i |
-					    ubo_layout_mask.flags.i)) != 0) {
-	      _mesa_glsl_error(& @3, state,
-			       "duplicate layout qualifiers used\n");
 	      YYERROR;
 	   }
-
-	   $$ = $1;
-
-	   if (($3.flags.i & ubo_mat_mask.flags.i) != 0)
-	      $$.flags.i &= ~ubo_mat_mask.flags.i;
-	   if (($3.flags.i & ubo_layout_mask.flags.i) != 0)
-	      $$.flags.i &= ~ubo_layout_mask.flags.i;
-
-	   $$.flags.i |= $3.flags.i;
-
-	   if ($3.flags.q.explicit_location)
-	      $$.location = $3.location;
-
-	   if ($3.flags.q.explicit_index)
-	      $$.index = $3.index;
 	}
 	;
 
@@ -1938,6 +1906,7 @@ external_declaration:
 	function_definition	{ $$ = $1; }
 	| declaration		{ $$ = $1; }
 	| pragma_statement	{ $$ = NULL; }
+	| layout_defaults	{ $$ = NULL; }
 	;
 
 function_definition:
@@ -1958,14 +1927,18 @@ uniform_block:
 	UNIFORM NEW_IDENTIFIER '{' member_list '}' ';'
 	{
 	   void *ctx = state;
-	   ast_type_qualifier no_qual;
+	   $$ = new(ctx) ast_uniform_block(*state->default_uniform_qualifier,
-	   memset(&no_qual, 0, sizeof(no_qual));
+					   $2, $4);
-	   $$ = new(ctx) ast_uniform_block(no_qual, $2, $4);
 	}
 	| layout_qualifier UNIFORM NEW_IDENTIFIER '{' member_list '}' ';'
 	{
 	   void *ctx = state;
-	   $$ = new(ctx) ast_uniform_block($1, $3, $5);
+
+	   ast_type_qualifier qual = *state->default_uniform_qualifier;
+	   if (!qual.merge_qualifier(& @1, state, $1)) {
+	      YYERROR;
+	   }
+	   $$ = new(ctx) ast_uniform_block(qual, $3, $5);
 	}
 	;
 
@@ -2019,3 +1992,12 @@ member_declaration:
 	   $$->declarations.push_degenerate_list_at_head(& $3->link);
 	}
 	;
+
+layout_defaults:
+	layout_qualifier UNIFORM ';'
+	{
+	   if (!state->default_uniform_qualifier->merge_qualifier(& @1, state,
+								  $1)) {
+	      YYERROR;
+	   }
+	}

src/glsl/glsl_parser_extras.cpp

@@ -107,6 +107,10 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
 
    if (ctx->Const.ForceGLSLExtensionsWarn)
       _mesa_glsl_process_extension("all", NULL, "warn", NULL, this);
+
+   this->default_uniform_qualifier = new(this) ast_type_qualifier();
+   this->default_uniform_qualifier->flags.q.shared = 1;
+   this->default_uniform_qualifier->flags.q.column_major = 1;
 }
 
 const char *

src/glsl/glsl_parser_extras.h

@@ -91,6 +91,13 @@ struct _mesa_glsl_parse_state {
    const char *version_string;
    enum _mesa_glsl_parser_targets target;
 
+   /**
+    * Default uniform layout qualifiers tracked during parsing.
+    * Currently affects uniform blocks and uniform buffer variables in
+    * those blocks.
+    */
+   class ast_type_qualifier *default_uniform_qualifier;
+
    /**
     * Printable list of GLSL versions supported by the current context
     *