1/*
2 * Copyright © 2010 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#include "ir.h"
25#include "glsl_parser_extras.h"
26#include "ast.h"
27#include "compiler/glsl_types.h"
28
29ir_rvalue *
30_mesa_ast_field_selection_to_hir(const ast_expression *expr,
31				 exec_list *instructions,
32				 struct _mesa_glsl_parse_state *state)
33{
34   void *ctx = state;
35   ir_rvalue *result = NULL;
36   ir_rvalue *op;
37
38   op = expr->subexpressions[0]->hir(instructions, state);
39
40   /* There are two kinds of field selection.  There is the selection of a
41    * specific field from a structure, and there is the selection of a
42    * swizzle / mask from a vector.  Which is which is determined entirely
43    * by the base type of the thing to which the field selection operator is
44    * being applied.
45    */
46   YYLTYPE loc = expr->get_location();
47   if (op->type->is_error()) {
48      /* silently propagate the error */
49   } else if (op->type->is_struct() || op->type->is_interface()) {
50      result = new(ctx) ir_dereference_record(op,
51					      expr->primary_expression.identifier);
52
53      if (result->type->is_error()) {
54	 _mesa_glsl_error(& loc, state, "cannot access field `%s' of "
55			  "structure",
56			  expr->primary_expression.identifier);
57      }
58   } else if (op->type->is_vector() ||
59              (state->has_420pack() && op->type->is_scalar())) {
60      ir_swizzle *swiz = ir_swizzle::create(op,
61					    expr->primary_expression.identifier,
62					    op->type->vector_elements);
63      if (swiz != NULL) {
64	 result = swiz;
65      } else {
66	 /* FINISHME: Logging of error messages should be moved into
67	  * FINISHME: ir_swizzle::create.  This allows the generation of more
68	  * FINISHME: specific error messages.
69	  */
70	 _mesa_glsl_error(& loc, state, "invalid swizzle / mask `%s'",
71			  expr->primary_expression.identifier);
72      }
73   } else {
74      _mesa_glsl_error(& loc, state, "cannot access field `%s' of "
75		       "non-structure / non-vector",
76		       expr->primary_expression.identifier);
77   }
78
79   return result ? result : ir_rvalue::error_value(ctx);
80}
81