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