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 
29 ir_rvalue *
_mesa_ast_field_selection_to_hir(const ast_expression * expr,exec_list * instructions,struct _mesa_glsl_parse_state * state)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