src/compiler/glsl/hir_field_selection.cpp

   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 *
  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->base_type == GLSL_TYPE_STRUCT
  50               || op->type->base_type == GLSL_TYPE_INTERFACE) {
  51       result = new(ctx) ir_dereference_record(op,
  52                                               expr->primary_expression.identifier);
  53
  54       if (result->type->is_error()) {
  55          _mesa_glsl_error(& loc, state, "cannot access field `%s' of "
  56                           "structure",
  57                           expr->primary_expression.identifier);
  58       }
  59    } else if (op->type->is_vector() ||
  60               (state->has_420pack() && op->type->is_scalar())) {
  61       ir_swizzle *swiz = ir_swizzle::create(op,
  62                                             expr->primary_expression.identifier,
  63                                             op->type->vector_elements);
  64       if (swiz != NULL) {
  65          result = swiz;
  66       } else {
  67          /* FINISHME: Logging of error messages should be moved into
  68           * FINISHME: ir_swizzle::create.  This allows the generation of more
  69           * FINISHME: specific error messages.
  70           */
  71          _mesa_glsl_error(& loc, state, "invalid swizzle / mask `%s'",
  72                           expr->primary_expression.identifier);
  73       }
  74    } else {
  75       _mesa_glsl_error(& loc, state, "cannot access field `%s' of "
  76                        "non-structure / non-vector",
  77                        expr->primary_expression.identifier);
  78    }
  79
  80    return result ? result : ir_rvalue::error_value(ctx);
  81 }