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    /* Section 2.11.6 (Uniform Variables) of the OpenGL ES 3.0.3 spec says:
  81     *
  82     *     "All members of a named uniform block declared with a shared or
  83     *     std140 layout qualifier are considered active, even if they are not
  84     *     referenced in any shader in the program. The uniform block itself is
  85     *     also considered active, even if no member of the block is
  86     *     referenced."
  87     */
  88    if (var->get_interface_type()->interface_packing ==
  89        GLSL_INTERFACE_PACKING_PACKED)
  90       return visit_continue;
  91
  92    /* Process the block.  Bail if there was an error.
  93     */
  94    link_uniform_block_active *const b =
  95       process_block(this->mem_ctx, this->ht, var);
  96    if (b == NULL) {
  97       linker_error(this->prog,
  98                    "uniform block `%s' has mismatching definitions",
  99                    var->get_interface_type()->name);
 100       this->success = false;
 101       return visit_stop;
 102    }
 103
 104    assert(b->num_array_elements == 0);
 105    assert(b->array_elements == NULL);
 106    assert(b->type != NULL);
 107    assert(!b->type->is_array() || b->has_instance_name);
 108
 109    /* For uniform block arrays declared with a shared or std140 layout
 110     * qualifier, mark all its instances as used.
 111     */
 112    if (b->type->is_array() && b->type->length > 0) {
 113       b->num_array_elements = b->type->length;
 114       b->array_elements = reralloc(this->mem_ctx,
 115                                    b->array_elements,
 116                                    unsigned,
 117                                    b->num_array_elements);
 118
 119       for (unsigned i = 0; i < b->num_array_elements; i++) {
 120          b->array_elements[i] = i;
 121       }
 122    }
 123
 124    return visit_continue;
 125 }
 126
 127 ir_visitor_status
 128 link_uniform_block_active_visitor::visit_enter(ir_dereference_array *ir)
 129 {
 130    ir_dereference_variable *const d = ir->array->as_dereference_variable();
 131    ir_variable *const var = (d == NULL) ? NULL : d->var;
 132
 133    /* If the r-value being dereferenced is not a variable (e.g., a field of a
 134     * structure) or is not a uniform block instance, continue.
 135     *
 136     * WARNING: It is not enough for the variable to be part of uniform block.
 137     * It must represent the entire block.  Arrays (or matrices) inside blocks
 138     * that lack an instance name are handled by the ir_dereference_variable
 139     * function.
 140     */
 141    if (var == NULL
 142        || !var->is_in_buffer_block()
 143        || !var->is_interface_instance())
 144       return visit_continue;
 145
 146    /* Process the block.  Bail if there was an error.
 147     */
 148    link_uniform_block_active *const b =
 149       process_block(this->mem_ctx, this->ht, var);
 150    if (b == NULL) {
 151       linker_error(prog,
 152                    "uniform block `%s' has mismatching definitions",
 153                    var->get_interface_type()->name);
 154       this->success = false;
 155       return visit_stop;
 156    }
 157
 158    /* Block arrays must be declared with an instance name.
 159     */
 160    assert(b->has_instance_name);
 161    assert((b->num_array_elements == 0) == (b->array_elements == NULL));
 162    assert(b->type != NULL);
 163
 164    /* If the block array was declared with a shared or
 165     * std140 layout qualifier, all its instances have been already marked
 166     * as used in link_uniform_block_active_visitor::visit(ir_variable *).
 167     */
 168    if (var->get_interface_type()->interface_packing !=
 169        GLSL_INTERFACE_PACKING_PACKED)
 170       return visit_continue_with_parent;
 171
 172    ir_constant *c = ir->array_index->as_constant();
 173
 174    if (c) {
 175       /* Index is a constant, so mark just that element used, if not already */
 176       const unsigned idx = c->get_uint_component(0);
 177
 178       unsigned i;
 179       for (i = 0; i < b->num_array_elements; i++) {
 180          if (b->array_elements[i] == idx)
 181             break;
 182       }
 183
 184       assert(i <= b->num_array_elements);
 185
 186       if (i == b->num_array_elements) {
 187          b->array_elements = reralloc(this->mem_ctx,
 188                                       b->array_elements,
 189                                       unsigned,
 190                                       b->num_array_elements + 1);
 191
 192          b->array_elements[b->num_array_elements] = idx;
 193
 194          b->num_array_elements++;
 195       }
 196    } else {
 197       /* The array index is not a constant, so mark the entire array used. */
 198       assert(b->type->is_array());
 199       if (b->num_array_elements < b->type->length) {
 200          b->num_array_elements = b->type->length;
 201          b->array_elements = reralloc(this->mem_ctx,
 202                                       b->array_elements,
 203                                       unsigned,
 204                                       b->num_array_elements);
 205
 206          for (unsigned i = 0; i < b->num_array_elements; i++) {
 207             b->array_elements[i] = i;
 208          }
 209       }
 210    }
 211
 212    return visit_continue_with_parent;
 213 }
 214
 215 ir_visitor_status
 216 link_uniform_block_active_visitor::visit(ir_dereference_variable *ir)
 217 {
 218    ir_variable *var = ir->var;
 219
 220    if (!var->is_in_buffer_block())
 221       return visit_continue;
 222
 223    assert(!var->is_interface_instance() || !var->type->is_array());
 224
 225    /* Process the block.  Bail if there was an error.
 226     */
 227    link_uniform_block_active *const b =
 228       process_block(this->mem_ctx, this->ht, var);
 229    if (b == NULL) {
 230       linker_error(this->prog,
 231                    "uniform block `%s' has mismatching definitions",
 232                    var->get_interface_type()->name);
 233       this->success = false;
 234       return visit_stop;
 235    }
 236
 237    assert(b->num_array_elements == 0);
 238    assert(b->array_elements == NULL);
 239    assert(b->type != NULL);
 240
 241    return visit_continue;
 242 }