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