src/glsl/link_uniform_block_active_visitor.cpp

   1 /*
   2  * Copyright © 2013 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 "link_uniform_block_active_visitor.h"
  25 #include "program.h"
  26
  27 link_uniform_block_active *
  28 process_block(void *mem_ctx, struct hash_table *ht, ir_variable *var)
  29 {
  30    const hash_entry *const existing_block =
  31       _mesa_hash_table_search(ht, var->get_interface_type()->name);
  32
  33    const glsl_type *const block_type = var->is_interface_instance()
  34       ? var->type : var->get_interface_type();
  35
  36
  37    /* If a block with this block-name has not previously been seen, add it.
  38     * If a block with this block-name has been seen, it must be identical to
  39     * the block currently being examined.
  40     */
  41    if (existing_block == NULL) {
  42       link_uniform_block_active *const b =
  43          rzalloc(mem_ctx, struct link_uniform_block_active);
  44
  45       b->type = block_type;
  46       b->has_instance_name = var->is_interface_instance();
  47
  48       if (var->data.explicit_binding) {
  49          b->has_binding = true;
  50          b->binding = var->data.binding;
  51       } else {
  52          b->has_binding = false;
  53          b->binding = 0;
  54       }
  55
  56       if (var->data.vk_set) {
  57          b->set = var->data.set;
  58          b->index = var->data.index;
  59       }
  60
  61       _mesa_hash_table_insert(ht, var->get_interface_type()->name, (void *) b);
  62       return b;
  63    } else {
  64       link_uniform_block_active *const b =
  65          (link_uniform_block_active *) existing_block->data;
  66
  67       if (b->type != block_type
  68           || b->has_instance_name != var->is_interface_instance())
  69          return NULL;
  70       else
  71          return b;
  72    }
  73
  74    assert(!"Should not get here.");
  75    return NULL;
  76 }
  77
  78 ir_visitor_status
  79 link_uniform_block_active_visitor::visit(ir_variable *var)
  80 {
  81    if (!var->is_in_uniform_block())
  82       return visit_continue;
  83
  84    const glsl_type *const block_type = var->is_interface_instance()
  85       ? var->type : var->get_interface_type();
  86
  87    /* Section 2.11.6 (Uniform Variables) of the OpenGL ES 3.0.3 spec says:
  88     *
  89     *     "All members of a named uniform block declared with a shared or
  90     *     std140 layout qualifier are considered active, even if they are not
  91     *     referenced in any shader in the program. The uniform block itself is
  92     *     also considered active, even if no member of the block is
  93     *     referenced."
  94     */
  95    if (block_type->interface_packing == GLSL_INTERFACE_PACKING_PACKED)
  96       return visit_continue;
  97
  98    /* Process the block.  Bail if there was an error.
  99     */
 100    link_uniform_block_active *const b =
 101       process_block(this->mem_ctx, this->ht, var);
 102    if (b == NULL) {
 103       linker_error(this->prog,
 104                    "uniform block `%s' has mismatching definitions",
 105                    var->get_interface_type()->name);
 106       this->success = false;
 107       return visit_stop;
 108    }
 109
 110    assert(b->num_array_elements == 0);
 111    assert(b->array_elements == NULL);
 112    assert(b->type != NULL);
 113
 114    return visit_continue;
 115 }
 116
 117 ir_visitor_status
 118 link_uniform_block_active_visitor::visit_enter(ir_dereference_array *ir)
 119 {
 120    ir_dereference_variable *const d = ir->array->as_dereference_variable();
 121    ir_variable *const var = (d == NULL) ? NULL : d->var;
 122
 123    /* If the r-value being dereferenced is not a variable (e.g., a field of a
 124     * structure) or is not a uniform block instance, continue.
 125     *
 126     * WARNING: It is not enough for the variable to be part of uniform block.
 127     * It must represent the entire block.  Arrays (or matrices) inside blocks
 128     * that lack an instance name are handled by the ir_dereference_variable
 129     * function.
 130     */
 131    if (var == NULL
 132        || !var->is_in_uniform_block()
 133        || !var->is_interface_instance())
 134       return visit_continue;
 135
 136    /* Process the block.  Bail if there was an error.
 137     */
 138    link_uniform_block_active *const b =
 139       process_block(this->mem_ctx, this->ht, var);
 140    if (b == NULL) {
 141       linker_error(prog,
 142                    "uniform block `%s' has mismatching definitions",
 143                    var->get_interface_type()->name);
 144       this->success = false;
 145       return visit_stop;
 146    }
 147
 148    /* Block arrays must be declared with an instance name.
 149     */
 150    assert(b->has_instance_name);
 151    assert((b->num_array_elements == 0) == (b->array_elements == NULL));
 152    assert(b->type != NULL);
 153
 154    ir_constant *c = ir->array_index->as_constant();
 155
 156    if (c) {
 157       /* Index is a constant, so mark just that element used, if not already */
 158       const unsigned idx = c->get_uint_component(0);
 159
 160       unsigned i;
 161       for (i = 0; i < b->num_array_elements; i++) {
 162          if (b->array_elements[i] == idx)
 163             break;
 164       }
 165
 166       assert(i <= b->num_array_elements);
 167
 168       if (i == b->num_array_elements) {
 169          b->array_elements = reralloc(this->mem_ctx,
 170                                       b->array_elements,
 171                                       unsigned,
 172                                       b->num_array_elements + 1);
 173
 174          b->array_elements[b->num_array_elements] = idx;
 175
 176          b->num_array_elements++;
 177       }
 178    } else {
 179       /* The array index is not a constant, so mark the entire array used. */
 180       assert(b->type->is_array());
 181       if (b->num_array_elements < b->type->length) {
 182          b->num_array_elements = b->type->length;
 183          b->array_elements = reralloc(this->mem_ctx,
 184                                       b->array_elements,
 185                                       unsigned,
 186                                       b->num_array_elements);
 187
 188          for (unsigned i = 0; i < b->num_array_elements; i++) {
 189             b->array_elements[i] = i;
 190          }
 191       }
 192    }
 193
 194    return visit_continue_with_parent;
 195 }
 196
 197 ir_visitor_status
 198 link_uniform_block_active_visitor::visit(ir_dereference_variable *ir)
 199 {
 200    ir_variable *var = ir->var;
 201
 202    if (!var->is_in_uniform_block())
 203       return visit_continue;
 204
 205    assert(!var->is_interface_instance() || !var->type->is_array());
 206
 207    /* Process the block.  Bail if there was an error.
 208     */
 209    link_uniform_block_active *const b =
 210       process_block(this->mem_ctx, this->ht, var);
 211    if (b == NULL) {
 212       linker_error(this->prog,
 213                    "uniform block `%s' has mismatching definitions",
 214                    var->get_interface_type()->name);
 215       this->success = false;
 216       return visit_stop;
 217    }
 218
 219    assert(b->num_array_elements == 0);
 220    assert(b->array_elements == NULL);
 221    assert(b->type != NULL);
 222
 223    return visit_continue;
 224 }