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 "program/symbol_table.h"
26#include "glsl_parser_extras.h"
27#include "ast.h"
28#include "glsl_types.h"
29
30ir_rvalue *
31_mesa_ast_field_selection_to_hir(const ast_expression *expr,
32				 exec_list *instructions,
33				 struct _mesa_glsl_parse_state *state)
34{
35   void *ctx = state;
36   ir_rvalue *result = NULL;
37   ir_rvalue *op;
38
39   op = expr->subexpressions[0]->hir(instructions, state);
40
41   /* There are two kinds of field selection.  There is the selection of a
42    * specific field from a structure, and there is the selection of a
43    * swizzle / mask from a vector.  Which is which is determined entirely
44    * by the base type of the thing to which the field selection operator is
45    * being applied.
46    */
47   YYLTYPE loc = expr->get_location();
48   if (op->type->is_error()) {
49      /* silently propagate the error */
50   } else if (op->type->is_vector()) {
51      ir_swizzle *swiz = ir_swizzle::create(op,
52					    expr->primary_expression.identifier,
53					    op->type->vector_elements);
54      if (swiz != NULL) {
55	 result = swiz;
56      } else {
57	 /* FINISHME: Logging of error messages should be moved into
58	  * FINISHME: ir_swizzle::create.  This allows the generation of more
59	  * FINISHME: specific error messages.
60	  */
61	 _mesa_glsl_error(& loc, state, "Invalid swizzle / mask `%s'",
62			  expr->primary_expression.identifier);
63      }
64   } else if (op->type->base_type == GLSL_TYPE_STRUCT) {
65      result = new(ctx) ir_dereference_record(op,
66					      expr->primary_expression.identifier);
67
68      if (result->type->is_error()) {
69	 _mesa_glsl_error(& loc, state, "Cannot access field `%s' of "
70			  "structure",
71			  expr->primary_expression.identifier);
72      }
73   } else if (expr->subexpressions[1] != NULL) {
74      /* Handle "method calls" in GLSL 1.20 - namely, array.length() */
75      if (state->language_version < 120)
76	 _mesa_glsl_error(&loc, state, "Methods not supported in GLSL 1.10.");
77
78      ast_expression *call = expr->subexpressions[1];
79      assert(call->oper == ast_function_call);
80
81      const char *method;
82      method = call->subexpressions[0]->primary_expression.identifier;
83
84      if (op->type->is_array() && strcmp(method, "length") == 0) {
85	 if (!call->expressions.is_empty())
86	    _mesa_glsl_error(&loc, state, "length method takes no arguments.");
87
88	 if (op->type->array_size() == 0)
89	    _mesa_glsl_error(&loc, state, "length called on unsized array.");
90
91	 result = new(ctx) ir_constant(op->type->array_size());
92      } else {
93	 _mesa_glsl_error(&loc, state, "Unknown method: `%s'.", method);
94      }
95   } else {
96      _mesa_glsl_error(& loc, state, "Cannot access field `%s' of "
97		       "non-structure / non-vector.",
98		       expr->primary_expression.identifier);
99   }
100
101   return result ? result : ir_rvalue::error_value(ctx);
102}
103